Commit Graph

42843 Commits

Author SHA1 Message Date
Linus Torvalds
3b517966c5 dma-mapping fixes for Linux 6.6
- fix the narea calculation in swiotlb initialization (Ross Lagerwall)
  - fix the check whether a device has used swiotlb (Petr Tesarik)
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Merge tag 'dma-mapping-6.6-2023-09-30' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix the narea calculation in swiotlb initialization (Ross Lagerwall)

 - fix the check whether a device has used swiotlb (Petr Tesarik)

* tag 'dma-mapping-6.6-2023-09-30' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: fix the check whether a device has used software IO TLB
  swiotlb: use the calculated number of areas
2023-09-30 11:07:26 -07:00
Hou Tao
9077fc228f bpf: Use kmalloc_size_roundup() to adjust size_index
Commit d52b59315b ("bpf: Adjust size_index according to the value of
KMALLOC_MIN_SIZE") uses KMALLOC_MIN_SIZE to adjust size_index, but as
reported by Nathan, the adjustment is not enough, because
__kmalloc_minalign() also decides the minimal alignment of slab object
as shown in new_kmalloc_cache() and its value may be greater than
KMALLOC_MIN_SIZE (e.g., 64 bytes vs 8 bytes under a riscv QEMU VM).

Instead of invoking __kmalloc_minalign() in bpf subsystem to find the
maximal alignment, just using kmalloc_size_roundup() directly to get the
corresponding slab object size for each allocation size. If these two
sizes are unmatched, adjust size_index to select a bpf_mem_cache with
unit_size equal to the object_size of the underlying slab cache for the
allocation size.

Fixes: 822fb26bdb ("bpf: Add a hint to allocated objects.")
Reported-by: Nathan Chancellor <nathan@kernel.org>
Closes: https://lore.kernel.org/bpf/20230914181407.GA1000274@dev-arch.thelio-3990X/
Signed-off-by: Hou Tao <houtao1@huawei.com>
Tested-by: Emil Renner Berthing <emil.renner.berthing@canonical.com>
Link: https://lore.kernel.org/r/20230928101558.2594068-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-30 09:39:28 -07:00
Baoquan He
e2a8f20dd8 Crash: add lock to serialize crash hotplug handling
Eric reported that handling corresponding crash hotplug event can be
failed easily when many memory hotplug event are notified in a short
period.  They failed because failing to take __kexec_lock.

=======
[   78.714569] Fallback order for Node 0: 0
[   78.714575] Built 1 zonelists, mobility grouping on.  Total pages: 1817886
[   78.717133] Policy zone: Normal
[   78.724423] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[   78.727207] crash hp: kexec_trylock() failed, elfcorehdr may be inaccurate
[   80.056643] PEFILE: Unsigned PE binary
=======

The memory hotplug events are notified very quickly and very many, while
the handling of crash hotplug is much slower relatively.  So the atomic
variable __kexec_lock and kexec_trylock() can't guarantee the
serialization of crash hotplug handling.

Here, add a new mutex lock __crash_hotplug_lock to serialize crash hotplug
handling specifically.  This doesn't impact the usage of __kexec_lock.

Link: https://lkml.kernel.org/r/20230926120905.392903-1-bhe@redhat.com
Fixes: 2472627561 ("crash: add generic infrastructure for crash hotplug support")
Signed-off-by: Baoquan He <bhe@redhat.com>
Tested-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Eric DeVolder <eric.devolder@oracle.com>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Cc: Sourabh Jain <sourabhjain@linux.ibm.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-29 17:20:48 -07:00
Daniel Borkmann
f9b0e1088b bpf, mprog: Fix maximum program check on mprog attachment
After Paul's recent improvement to syzkaller to improve coverage for
bpf_mprog and tcx, it hit a splat that the program limit was surpassed.
What happened is that the maximum number of progs got added, followed
by another prog add request which adds with BPF_F_BEFORE flag relative
to the last program in the array. The idx >= bpf_mprog_max() check in
bpf_mprog_attach() still passes because the index is below the maximum
but the maximum will be surpassed. We need to add a check upfront for
insertions to catch this situation.

Fixes: 053c8e1f23 ("bpf: Add generic attach/detach/query API for multi-progs")
Reported-by: syzbot+baa44e3dbbe48e05c1ad@syzkaller.appspotmail.com
Reported-by: syzbot+b97d20ed568ce0951a06@syzkaller.appspotmail.com
Reported-by: syzbot+2558ca3567a77b7af4e3@syzkaller.appspotmail.com
Co-developed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: syzbot+baa44e3dbbe48e05c1ad@syzkaller.appspotmail.com
Tested-by: syzbot+b97d20ed568ce0951a06@syzkaller.appspotmail.com
Link: https://github.com/google/syzkaller/pull/4207
Link: https://lore.kernel.org/bpf/20230929204121.20305-1-daniel@iogearbox.net
2023-09-29 15:49:57 -07:00
Joel Fernandes (Google)
fc09027786 sched/rt: Fix live lock between select_fallback_rq() and RT push
During RCU-boost testing with the TREE03 rcutorture config, I found that
after a few hours, the machine locks up.

On tracing, I found that there is a live lock happening between 2 CPUs.
One CPU has an RT task running, while another CPU is being offlined
which also has an RT task running.  During this offlining, all threads
are migrated. The migration thread is repeatedly scheduled to migrate
actively running tasks on the CPU being offlined. This results in a live
lock because select_fallback_rq() keeps picking the CPU that an RT task
is already running on only to get pushed back to the CPU being offlined.

It is anyway pointless to pick CPUs for pushing tasks to if they are
being offlined only to get migrated away to somewhere else. This could
also add unwanted latency to this task.

Fix these issues by not selecting CPUs in RT if they are not 'active'
for scheduling, using the cpu_active_mask. Other parts in core.c already
use cpu_active_mask to prevent tasks from being put on CPUs going
offline.

With this fix I ran the tests for days and could not reproduce the
hang. Without the patch, I hit it in a few hours.

Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Paul E. McKenney <paulmck@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20230923011409.3522762-1-joel@joelfernandes.org
2023-09-28 22:58:13 +02:00
Petr Tesarik
2d5780bbef swiotlb: fix the check whether a device has used software IO TLB
When CONFIG_SWIOTLB_DYNAMIC=y, devices which do not use the software IO TLB
can avoid swiotlb lookup. A flag is added by commit 1395706a14 ("swiotlb:
search the software IO TLB only if the device makes use of it"), the flag
is correctly set, but it is then never checked. Add the actual check here.

Note that this code is an alternative to the default pool check, not an
additional check, because:

1. swiotlb_find_pool() also searches the default pool;
2. if dma_uses_io_tlb is false, the default swiotlb pool is not used.

Tested in a KVM guest against a QEMU RAM-backed SATA disk over virtio and
*not* using software IO TLB, this patch increases IOPS by approx 2% for
4-way parallel I/O.

The write memory barrier in swiotlb_dyn_alloc() is not needed, because a
newly allocated pool must always be observed by swiotlb_find_slots() before
an address from that pool is passed to is_swiotlb_buffer().

Correctness was verified using the following litmus test:

C swiotlb-new-pool

(*
 * Result: Never
 *
 * Check that a newly allocated pool is always visible when the
 *  corresponding swiotlb buffer is visible.
 *)

{
	mem_pools = default;
}

P0(int **mem_pools, int *pool)
{
	/* add_mem_pool() */
	WRITE_ONCE(*pool, 999);
	rcu_assign_pointer(*mem_pools, pool);
}

P1(int **mem_pools, int *flag, int *buf)
{
	/* swiotlb_find_slots() */
	int *r0;
	int r1;

	rcu_read_lock();
	r0 = READ_ONCE(*mem_pools);
	r1 = READ_ONCE(*r0);
	rcu_read_unlock();

	if (r1) {
		WRITE_ONCE(*flag, 1);
		smp_mb();
	}

	/* device driver (presumed) */
	WRITE_ONCE(*buf, r1);
}

P2(int **mem_pools, int *flag, int *buf)
{
	/* device driver (presumed) */
	int r0 = READ_ONCE(*buf);

	/* is_swiotlb_buffer() */
	int r1;
	int *r2;
	int r3;

	smp_rmb();
	r1 = READ_ONCE(*flag);
	if (r1) {
		/* swiotlb_find_pool() */
		rcu_read_lock();
		r2 = READ_ONCE(*mem_pools);
		r3 = READ_ONCE(*r2);
		rcu_read_unlock();
	}
}

exists (2:r0<>0 /\ 2:r3=0) (* Not found. *)

Fixes: 1395706a14 ("swiotlb: search the software IO TLB only if the device makes use of it")
Reported-by: Jonathan Corbet <corbet@lwn.net>
Closes: https://lore.kernel.org/linux-iommu/87a5uz3ob8.fsf@meer.lwn.net/
Signed-off-by: Petr Tesarik <petr@tesarici.cz>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-09-27 11:19:15 +02:00
Linus Torvalds
0e945134b6 Workqueue fixes for v6.6-rc3
* Remove double allocation of wq_update_pod_attrs_buf.
 
 * Fix missing allocation of pwq_release_worker when
   wq_cpu_intensive_thresh_us is set to a custom value.
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Merge tag 'wq-for-6.6-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq

Pull workqueue fixes from Tejun Heo:

 - Remove double allocation of wq_update_pod_attrs_buf

 - Fix missing allocation of pwq_release_worker when
   wq_cpu_intensive_thresh_us is set to a custom value

* tag 'wq-for-6.6-rc3-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
  workqueue: Fix missed pwq_release_worker creation in wq_cpu_intensive_thresh_init()
  workqueue: Removed double allocation of wq_update_pod_attrs_buf
2023-09-26 11:36:17 -07:00
Jiri Olsa
dd8657894c bpf: Count missed stats in trace_call_bpf
Increase misses stats in case bpf array execution is skipped
because of recursion check in trace_call_bpf.

Adding bpf_prog_inc_misses_counters that increase misses
counts for all bpf programs in bpf_prog_array.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20230920213145.1941596-5-jolsa@kernel.org
2023-09-25 16:37:44 -07:00
Jiri Olsa
3acf8ace68 bpf: Add missed value to kprobe perf link info
Add missed value to kprobe attached through perf link info to
hold the stats of missed kprobe handler execution.

The kprobe's missed counter gets incremented when kprobe handler
is not executed due to another kprobe running on the same cpu.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230920213145.1941596-4-jolsa@kernel.org
2023-09-25 16:37:44 -07:00
Jiri Olsa
e2b2cd592a bpf: Add missed value to kprobe_multi link info
Add missed value to kprobe_multi link info to hold the stats of missed
kprobe_multi probe.

The missed counter gets incremented when fprobe fails the recursion
check or there's no rethook available for return probe. In either
case the attached bpf program is not executed.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/bpf/20230920213145.1941596-3-jolsa@kernel.org
2023-09-25 16:37:44 -07:00
Jiri Olsa
f915fcb385 bpf: Count stats for kprobe_multi programs
Adding support to gather missed stats for kprobe_multi
programs due to bpf_prog_active protection.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Song Liu <song@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20230920213145.1941596-2-jolsa@kernel.org
2023-09-25 16:37:44 -07:00
Linus Torvalds
5edc6bb321 Tracing fixes for 6.6-rc2:
- Fix the "bytes" output of the per_cpu stat file
   The tracefs/per_cpu/cpu*/stats "bytes" was giving bogus values as the
   accounting was not accurate. It is suppose to show how many used bytes are
   still in the ring buffer, but even when the ring buffer was empty it would
   still show there were bytes used.
 
 - Fix a bug in eventfs where reading a dynamic event directory (open) and then
   creating a dynamic event that goes into that diretory screws up the accounting.
   On close, the newly created event dentry will get a "dput" without ever having
   a "dget" done for it. The fix is to allocate an array on dir open to save what
   dentries were actually "dget" on, and what ones to "dput" on close.
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Merge tag 'trace-v6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Fix the "bytes" output of the per_cpu stat file

   The tracefs/per_cpu/cpu*/stats "bytes" was giving bogus values as the
   accounting was not accurate. It is suppose to show how many used
   bytes are still in the ring buffer, but even when the ring buffer was
   empty it would still show there were bytes used.

 - Fix a bug in eventfs where reading a dynamic event directory (open)
   and then creating a dynamic event that goes into that diretory screws
   up the accounting.

   On close, the newly created event dentry will get a "dput" without
   ever having a "dget" done for it. The fix is to allocate an array on
   dir open to save what dentries were actually "dget" on, and what ones
   to "dput" on close.

* tag 'trace-v6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Remember what dentries were created on dir open
  ring-buffer: Fix bytes info in per_cpu buffer stats
2023-09-24 13:55:34 -07:00
Linus Torvalds
85eba5f175 13 hotfixes, 10 of which pertain to post-6.5 issues. The other 3 are
cc:stable.
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Merge tag 'mm-hotfixes-stable-2023-09-23-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull misc fixes from Andrew Morton:
 "13 hotfixes, 10 of which pertain to post-6.5 issues. The other three
  are cc:stable"

* tag 'mm-hotfixes-stable-2023-09-23-10-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
  proc: nommu: fix empty /proc/<pid>/maps
  filemap: add filemap_map_order0_folio() to handle order0 folio
  proc: nommu: /proc/<pid>/maps: release mmap read lock
  mm: memcontrol: fix GFP_NOFS recursion in memory.high enforcement
  pidfd: prevent a kernel-doc warning
  argv_split: fix kernel-doc warnings
  scatterlist: add missing function params to kernel-doc
  selftests/proc: fixup proc-empty-vm test after KSM changes
  revert "scripts/gdb/symbols: add specific ko module load command"
  selftests: link libasan statically for tests with -fsanitize=address
  task_work: add kerneldoc annotation for 'data' argument
  mm: page_alloc: fix CMA and HIGHATOMIC landing on the wrong buddy list
  sh: mm: re-add lost __ref to ioremap_prot() to fix modpost warning
2023-09-23 11:51:16 -07:00
Zheng Yejian
45d99ea451 ring-buffer: Fix bytes info in per_cpu buffer stats
The 'bytes' info in file 'per_cpu/cpu<X>/stats' means the number of
bytes in cpu buffer that have not been consumed. However, currently
after consuming data by reading file 'trace_pipe', the 'bytes' info
was not changed as expected.

  # cat per_cpu/cpu0/stats
  entries: 0
  overrun: 0
  commit overrun: 0
  bytes: 568             <--- 'bytes' is problematical !!!
  oldest event ts:  8651.371479
  now ts:  8653.912224
  dropped events: 0
  read events: 8

The root cause is incorrect stat on cpu_buffer->read_bytes. To fix it:
  1. When stat 'read_bytes', account consumed event in rb_advance_reader();
  2. When stat 'entries_bytes', exclude the discarded padding event which
     is smaller than minimum size because it is invisible to reader. Then
     use rb_page_commit() instead of BUF_PAGE_SIZE at where accounting for
     page-based read/remove/overrun.

Also correct the comments of ring_buffer_bytes_cpu() in this patch.

Link: https://lore.kernel.org/linux-trace-kernel/20230921125425.1708423-1-zhengyejian1@huawei.com

Cc: stable@vger.kernel.org
Fixes: c64e148a3b ("trace: Add ring buffer stats to measure rate of events")
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-22 16:57:14 -04:00
Linus Torvalds
5b47b5766b Fix a PF_IDLE initialization bug that generated warnings on tiny-RCU.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2023-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fix from Ingo Molnar:
 "Fix a PF_IDLE initialization bug that generated warnings on tiny-RCU"

* tag 'sched-urgent-2023-09-22' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  kernel/sched: Modify initial boot task idle setup
2023-09-22 12:16:46 -07:00
Ilya Leoshkevich
577c06af81 bpf: Disable zero-extension for BPF_MEMSX
On the architectures that use bpf_jit_needs_zext(), e.g., s390x, the
verifier incorrectly inserts a zero-extension after BPF_MEMSX, leading
to miscompilations like the one below:

      24:       89 1a ff fe 00 00 00 00 "r1 = *(s16 *)(r10 - 2);"       # zext_dst set
   0x3ff7fdb910e:       lgh     %r2,-2(%r13,%r0)                        # load halfword
   0x3ff7fdb9114:       llgfr   %r2,%r2                                 # wrong!
      25:       65 10 00 03 00 00 7f ff if r1 s> 32767 goto +3 <l0_1>   # check_cond_jmp_op()

Disable such zero-extensions. The JITs need to insert sign-extension
themselves, if necessary.

Suggested-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Reviewed-by: Puranjay Mohan <puranjay12@gmail.com>
Link: https://lore.kernel.org/r/20230919101336.2223655-2-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-21 14:21:59 -07:00
Paolo Abeni
e9cbc89067 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

No conflicts.

Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2023-09-21 21:49:45 +02:00
Linus Torvalds
27bbf45eae Networking fixes for 6.6-rc2, including fixes from netfilter and bpf
Current release - regressions:
 
  - bpf: adjust size_index according to the value of KMALLOC_MIN_SIZE
 
  - netfilter: fix entries val in rule reset audit log
 
  - eth: stmmac: fix incorrect rxq|txq_stats reference
 
 Previous releases - regressions:
 
  - ipv4: fix null-deref in ipv4_link_failure
 
  - netfilter:
    - fix several GC related issues
    - fix race between IPSET_CMD_CREATE and IPSET_CMD_SWAP
 
  - eth: team: fix null-ptr-deref when team device type is changed
 
  - eth: i40e: fix VF VLAN offloading when port VLAN is configured
 
  - eth: ionic: fix 16bit math issue when PAGE_SIZE >= 64KB
 
 Previous releases - always broken:
 
  - core: fix ETH_P_1588 flow dissector
 
  - mptcp: fix several connection hang-up conditions
 
  - bpf:
    - avoid deadlock when using queue and stack maps from NMI
    - add override check to kprobe multi link attach
 
  - hsr: properly parse HSRv1 supervisor frames.
 
  - eth: igc: fix infinite initialization loop with early XDP redirect
 
  - eth: octeon_ep: fix tx dma unmap len values in SG
 
  - eth: hns3: fix GRE checksum offload issue
 
 Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-6.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking fixes from Paolo Abeni:
 "Including fixes from netfilter and bpf.

  Current release - regressions:

   - bpf: adjust size_index according to the value of KMALLOC_MIN_SIZE

   - netfilter: fix entries val in rule reset audit log

   - eth: stmmac: fix incorrect rxq|txq_stats reference

  Previous releases - regressions:

   - ipv4: fix null-deref in ipv4_link_failure

   - netfilter:
      - fix several GC related issues
      - fix race between IPSET_CMD_CREATE and IPSET_CMD_SWAP

   - eth: team: fix null-ptr-deref when team device type is changed

   - eth: i40e: fix VF VLAN offloading when port VLAN is configured

   - eth: ionic: fix 16bit math issue when PAGE_SIZE >= 64KB

  Previous releases - always broken:

   - core: fix ETH_P_1588 flow dissector

   - mptcp: fix several connection hang-up conditions

   - bpf:
      - avoid deadlock when using queue and stack maps from NMI
      - add override check to kprobe multi link attach

   - hsr: properly parse HSRv1 supervisor frames.

   - eth: igc: fix infinite initialization loop with early XDP redirect

   - eth: octeon_ep: fix tx dma unmap len values in SG

   - eth: hns3: fix GRE checksum offload issue"

* tag 'net-6.6-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (87 commits)
  sfc: handle error pointers returned by rhashtable_lookup_get_insert_fast()
  igc: Expose tx-usecs coalesce setting to user
  octeontx2-pf: Do xdp_do_flush() after redirects.
  bnxt_en: Flush XDP for bnxt_poll_nitroa0()'s NAPI
  net: ena: Flush XDP packets on error.
  net/handshake: Fix memory leak in __sock_create() and sock_alloc_file()
  net: hinic: Fix warning-hinic_set_vlan_fliter() warn: variable dereferenced before check 'hwdev'
  netfilter: ipset: Fix race between IPSET_CMD_CREATE and IPSET_CMD_SWAP
  netfilter: nf_tables: fix memleak when more than 255 elements expired
  netfilter: nf_tables: disable toggling dormant table state more than once
  vxlan: Add missing entries to vxlan_get_size()
  net: rds: Fix possible NULL-pointer dereference
  team: fix null-ptr-deref when team device type is changed
  net: bridge: use DEV_STATS_INC()
  net: hns3: add 5ms delay before clear firmware reset irq source
  net: hns3: fix fail to delete tc flower rules during reset issue
  net: hns3: only enable unicast promisc when mac table full
  net: hns3: fix GRE checksum offload issue
  net: hns3: add cmdq check for vf periodic service task
  net: stmmac: fix incorrect rxq|txq_stats reference
  ...
2023-09-21 11:28:16 -07:00
Andrii Nakryiko
81335f90e8 bpf: unconditionally reset backtrack_state masks on global func exit
In mark_chain_precision() logic, when we reach the entry to a global
func, it is expected that R1-R5 might be still requested to be marked
precise. This would correspond to some integer input arguments being
tracked as precise. This is all expected and handled as a special case.

What's not expected is that we'll leave backtrack_state structure with
some register bits set. This is because for subsequent precision
propagations backtrack_state is reused without clearing masks, as all
code paths are carefully written in a way to leave empty backtrack_state
with zeroed out masks, for speed.

The fix is trivial, we always clear register bit in the register mask, and
then, optionally, set reg->precise if register is SCALAR_VALUE type.

Reported-by: Chris Mason <clm@meta.com>
Fixes: be2ef81615 ("bpf: allow precision tracking for programs with subprogs")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230918210110.2241458-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-20 03:26:25 -07:00
Randy Dunlap
0c7752d5b1 pidfd: prevent a kernel-doc warning
Change the comment to match the function name that the SYSCALL_DEFINE()
macros generate to prevent a kernel-doc warning.

kernel/pid.c:628: warning: expecting prototype for pidfd_open(). Prototype was for sys_pidfd_open() instead

Link: https://lkml.kernel.org/r/20230912060822.2500-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-19 13:21:33 -07:00
Jens Axboe
4653e5dd04 task_work: add kerneldoc annotation for 'data' argument
A previous commit changed the arguments to task_work_cancel_match(), but
didn't document all of them.

Link: https://lkml.kernel.org/r/93938bff-baa3-4091-85f5-784aae297a07@kernel.dk
Fixes: c7aab1a7c5 ("task_work: add helper for more targeted task_work canceling")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309120307.zis3yQGe-lkp@intel.com/
Acked-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2023-09-19 13:21:32 -07:00
Alexei Starovoitov
aec42f3623 bpf: Remove unused variables.
Remove unused prev_offset, min_size, krec_size variables.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202309190634.fL17FWoT-lkp@intel.com/
Fixes: aaa619ebcc ("bpf: Refactor check_btf_func and split into two phases")
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-19 02:26:47 -07:00
Kumar Kartikeya Dwivedi
7d3460632d bpf: Fix bpf_throw warning on 32-bit arch
On 32-bit architectures, the pointer width is 32-bit, while we try to
cast from a u64 down to it, the compiler complains on mismatch in
integer size. Fix this by first casting to long which should match
the pointer width on targets supported by Linux.

Fixes: ec5290a178 ("bpf: Prevent KASAN false positive with bpf_throw")
Reported-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Tested-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Link: https://lore.kernel.org/r/20230918155233.297024-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-19 02:07:36 -07:00
Liam R. Howlett
cff9b2332a kernel/sched: Modify initial boot task idle setup
Initial booting is setting the task flag to idle (PF_IDLE) by the call
path sched_init() -> init_idle().  Having the task idle and calling
call_rcu() in kernel/rcu/tiny.c means that TIF_NEED_RESCHED will be
set.  Subsequent calls to any cond_resched() will enable IRQs,
potentially earlier than the IRQ setup has completed.  Recent changes
have caused just this scenario and IRQs have been enabled early.

This causes a warning later in start_kernel() as interrupts are enabled
before they are fully set up.

Fix this issue by setting the PF_IDLE flag later in the boot sequence.

Although the boot task was marked as idle since (at least) d80e4fda576d,
I am not sure that it is wrong to do so.  The forced context-switch on
idle task was introduced in the tiny_rcu update, so I'm going to claim
this fixes 5f6130fa52.

Fixes: 5f6130fa52 ("tiny_rcu: Directly force QS when call_rcu_[bh|sched]() on idle_task")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/linux-mm/CAMuHMdWpvpWoDa=Ox-do92czYRvkok6_x6pYUH+ZouMcJbXy+Q@mail.gmail.com/
2023-09-19 10:48:04 +02:00
Zqiang
dd64c873ed workqueue: Fix missed pwq_release_worker creation in wq_cpu_intensive_thresh_init()
Currently, if the wq_cpu_intensive_thresh_us is set to specific
value, will cause the wq_cpu_intensive_thresh_init() early exit
and missed creation of pwq_release_worker. this commit therefore
create the pwq_release_worker in advance before checking the
wq_cpu_intensive_thresh_us.

Signed-off-by: Zqiang <qiang.zhang1211@gmail.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Fixes: 967b494e2f ("workqueue: Use a kthread_worker to release pool_workqueues")
2023-09-18 08:50:31 -10:00
Steven Rostedt (Google)
a682821448 workqueue: Removed double allocation of wq_update_pod_attrs_buf
First commit 2930155b2e ("workqueue: Initialize unbound CPU pods later in
the boot") added the initialization of wq_update_pod_attrs_buf to
workqueue_init_early(), and then latter on, commit 84193c0710
("workqueue: Generalize unbound CPU pods") added it as well. This appeared
in a kmemleak run where the second allocation made the first allocation
leak.

Fixes: 84193c0710 ("workqueue: Generalize unbound CPU pods")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Tejun Heo <tj@kernel.org>
2023-09-18 08:35:25 -10:00
Linus Torvalds
e5a710d132 Fix a performance regression on large SMT systems, an Intel SMT4
balancing bug, and a topology setup bug on (Intel) hybrid processors.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler fixes from Ingo Molnar:
 "Fix a performance regression on large SMT systems, an Intel SMT4
  balancing bug, and a topology setup bug on (Intel) hybrid processors"

* tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sched: Restore the SD_ASYM_PACKING flag in the DIE domain
  sched/fair: Fix SMT4 group_smt_balance handling
  sched/fair: Optimize should_we_balance() for large SMT systems
2023-09-17 11:10:23 -07:00
Linus Torvalds
99a73f9e8d Fix a missing preempt-enable in the WARN() slowpath.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull WARN fix from Ingo Molnar:
 "Fix a missing preempt-enable in the WARN() slowpath"

* tag 'core-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  panic: Reenable preemption in WARN slowpath
2023-09-17 10:55:35 -07:00
David S. Miller
685c6d5b2c Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:

====================
The following pull-request contains BPF updates for your *net-next* tree.

We've added 73 non-merge commits during the last 9 day(s) which contain
a total of 79 files changed, 5275 insertions(+), 600 deletions(-).

The main changes are:

1) Basic BTF validation in libbpf, from Andrii Nakryiko.

2) bpf_assert(), bpf_throw(), exceptions in bpf progs, from Kumar Kartikeya Dwivedi.

3) next_thread cleanups, from Oleg Nesterov.

4) Add mcpu=v4 support to arm32, from Puranjay Mohan.

5) Add support for __percpu pointers in bpf progs, from Yonghong Song.

6) Fix bpf tailcall interaction with bpf trampoline, from Leon Hwang.

7) Raise irq_work in bpf_mem_alloc while irqs are disabled to improve refill probabablity, from Hou Tao.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Alan Maguire, Andrey Konovalov, Dave Marchevsky, "Eric W. Biederman",
Jiri Olsa, Maciej Fijalkowski, Quentin Monnet, Russell King (Oracle),
Song Liu, Stanislav Fomichev, Yonghong Song
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-17 15:12:06 +01:00
Kumar Kartikeya Dwivedi
06d686f771 bpf: Fix kfunc callback register type handling
The kfunc code to handle KF_ARG_PTR_TO_CALLBACK does not check the reg
type before using reg->subprogno. This can accidently permit invalid
pointers from being passed into callback helpers (e.g. silently from
different paths). Likewise, reg->subprogno from the per-register type
union may not be meaningful either. We need to reject any other type
except PTR_TO_FUNC.

Acked-by: Dave Marchevsky <davemarchevsky@fb.com>
Fixes: 5d92ddc3de ("bpf: Add callback validation to kfunc verifier logic")
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-14-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:36:43 -07:00
Kumar Kartikeya Dwivedi
fd548e1a46 bpf: Disallow fentry/fexit/freplace for exception callbacks
During testing, it was discovered that extensions to exception callbacks
had no checks, upon running a testcase, the kernel ended up running off
the end of a program having final call as bpf_throw, and hitting int3
instructions.

The reason is that while the default exception callback would have reset
the stack frame to return back to the main program's caller, the
replacing extension program will simply return back to bpf_throw, which
will instead return back to the program and the program will continue
execution, now in an undefined state where anything could happen.

The way to support extensions to an exception callback would be to mark
the BPF_PROG_TYPE_EXT main subprog as an exception_cb, and prevent it
from calling bpf_throw. This would make the JIT produce a prologue that
restores saved registers and reset the stack frame. But let's not do
that until there is a concrete use case for this, and simply disallow
this for now.

Similar issues will exist for fentry and fexit cases, where trampoline
saves data on the stack when invoking exception callback, which however
will then end up resetting the stack frame, and on return, the fexit
program will never will invoked as the return address points to the main
program's caller in the kernel. Instead of additional complexity and
back and forth between the two stacks to enable such a use case, simply
forbid it.

One key point here to note is that currently X86_TAIL_CALL_OFFSET didn't
require any modifications, even though we emit instructions before the
corresponding endbr64 instruction. This is because we ensure that a main
subprog never serves as an exception callback, and therefore the
exception callback (which will be a global subprog) can never serve as
the tail call target, eliminating any discrepancies. However, once we
support a BPF_PROG_TYPE_EXT to also act as an exception callback, it
will end up requiring change to the tail call offset to account for the
extra instructions. For simplicitly, tail calls could be disabled for
such targets.

Noting the above, it appears better to wait for a concrete use case
before choosing to permit extension programs to replace exception
callbacks.

As a precaution, we disable fentry and fexit for exception callbacks as
well.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-13-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:36:32 -07:00
Kumar Kartikeya Dwivedi
66d9111f35 bpf: Detect IP == ksym.end as part of BPF program
Now that bpf_throw kfunc is the first such call instruction that has
noreturn semantics within the verifier, this also kicks in dead code
elimination in unprecedented ways. For one, any instruction following
a bpf_throw call will never be marked as seen. Moreover, if a callchain
ends up throwing, any instructions after the call instruction to the
eventually throwing subprog in callers will also never be marked as
seen.

The tempting way to fix this would be to emit extra 'int3' instructions
which bump the jited_len of a program, and ensure that during runtime
when a program throws, we can discover its boundaries even if the call
instruction to bpf_throw (or to subprogs that always throw) is emitted
as the final instruction in the program.

An example of such a program would be this:

do_something():
	...
	r0 = 0
	exit

foo():
	r1 = 0
	call bpf_throw
	r0 = 0
	exit

bar(cond):
	if r1 != 0 goto pc+2
	call do_something
	exit
	call foo
	r0 = 0  // Never seen by verifier
	exit	//

main(ctx):
	r1 = ...
	call bar
	r0 = 0
	exit

Here, if we do end up throwing, the stacktrace would be the following:

bpf_throw
foo
bar
main

In bar, the final instruction emitted will be the call to foo, as such,
the return address will be the subsequent instruction (which the JIT
emits as int3 on x86). This will end up lying outside the jited_len of
the program, thus, when unwinding, we will fail to discover the return
address as belonging to any program and end up in a panic due to the
unreliable stack unwinding of BPF programs that we never expect.

To remedy this case, make bpf_prog_ksym_find treat IP == ksym.end as
part of the BPF program, so that is_bpf_text_address returns true when
such a case occurs, and we are able to unwind reliably when the final
instruction ends up being a call instruction.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-12-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:22 -07:00
Kumar Kartikeya Dwivedi
ec5290a178 bpf: Prevent KASAN false positive with bpf_throw
The KASAN stack instrumentation when CONFIG_KASAN_STACK is true poisons
the stack of a function when it is entered and unpoisons it when
leaving. However, in the case of bpf_throw, we will never return as we
switch our stack frame to the BPF exception callback. Later, this
discrepancy will lead to confusing KASAN splats when kernel resumes
execution on return from the BPF program.

Fix this by unpoisoning everything below the stack pointer of the BPF
program, which should cover the range that would not be unpoisoned. An
example splat is below:

BUG: KASAN: stack-out-of-bounds in stack_trace_consume_entry+0x14e/0x170
Write of size 8 at addr ffffc900013af958 by task test_progs/227

CPU: 0 PID: 227 Comm: test_progs Not tainted 6.5.0-rc2-g43f1c6c9052a-dirty #26
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.2-2.fc39 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x4a/0x80
 print_report+0xcf/0x670
 ? arch_stack_walk+0x79/0x100
 kasan_report+0xda/0x110
 ? stack_trace_consume_entry+0x14e/0x170
 ? stack_trace_consume_entry+0x14e/0x170
 ? __pfx_stack_trace_consume_entry+0x10/0x10
 stack_trace_consume_entry+0x14e/0x170
 ? __sys_bpf+0xf2e/0x41b0
 arch_stack_walk+0x8b/0x100
 ? __sys_bpf+0xf2e/0x41b0
 ? bpf_prog_test_run_skb+0x341/0x1c70
 ? bpf_prog_test_run_skb+0x341/0x1c70
 stack_trace_save+0x9b/0xd0
 ? __pfx_stack_trace_save+0x10/0x10
 ? __kasan_slab_free+0x109/0x180
 ? bpf_prog_test_run_skb+0x341/0x1c70
 ? __sys_bpf+0xf2e/0x41b0
 ? __x64_sys_bpf+0x78/0xc0
 ? do_syscall_64+0x3c/0x90
 ? entry_SYSCALL_64_after_hwframe+0x6e/0xd8
 kasan_save_stack+0x33/0x60
 ? kasan_save_stack+0x33/0x60
 ? kasan_set_track+0x25/0x30
 ? kasan_save_free_info+0x2b/0x50
 ? __kasan_slab_free+0x109/0x180
 ? kmem_cache_free+0x191/0x460
 ? bpf_prog_test_run_skb+0x341/0x1c70
 kasan_set_track+0x25/0x30
 kasan_save_free_info+0x2b/0x50
 __kasan_slab_free+0x109/0x180
 kmem_cache_free+0x191/0x460
 bpf_prog_test_run_skb+0x341/0x1c70
 ? __pfx_bpf_prog_test_run_skb+0x10/0x10
 ? __fget_light+0x51/0x220
 __sys_bpf+0xf2e/0x41b0
 ? __might_fault+0xa2/0x170
 ? __pfx___sys_bpf+0x10/0x10
 ? lock_release+0x1de/0x620
 ? __might_fault+0xcd/0x170
 ? __pfx_lock_release+0x10/0x10
 ? __pfx_blkcg_maybe_throttle_current+0x10/0x10
 __x64_sys_bpf+0x78/0xc0
 ? syscall_enter_from_user_mode+0x20/0x50
 do_syscall_64+0x3c/0x90
 entry_SYSCALL_64_after_hwframe+0x6e/0xd8
RIP: 0033:0x7f0fbb38880d
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d
89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d f3 45 12 00 f7 d8 64
89 01 48
RSP: 002b:00007ffe13907de8 EFLAGS: 00000206 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007ffe13908708 RCX: 00007f0fbb38880d
RDX: 0000000000000050 RSI: 00007ffe13907e20 RDI: 000000000000000a
RBP: 00007ffe13907e00 R08: 0000000000000000 R09: 00007ffe13907e20
R10: 0000000000000064 R11: 0000000000000206 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f0fbb532000 R15: 0000000000cfbd90
 </TASK>

The buggy address belongs to stack of task test_progs/227
KASAN internal error: frame info validation failed; invalid marker: 0

The buggy address belongs to the virtual mapping at
 [ffffc900013a8000, ffffc900013b1000) created by:
 kernel_clone+0xcd/0x600

The buggy address belongs to the physical page:
page:00000000b70f4332 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11418f
flags: 0x2fffe0000000000(node=0|zone=2|lastcpupid=0x7fff)
page_type: 0xffffffff()
raw: 02fffe0000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffffc900013af800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900013af880: 00 00 00 f1 f1 f1 f1 00 00 00 f3 f3 f3 f3 f3 00
>ffffc900013af900: 00 00 00 00 00 00 00 00 00 00 00 f1 00 00 00 00
                                                    ^
 ffffc900013af980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc900013afa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
Disabling lock debugging due to kernel taint

Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-11-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:22 -07:00
Kumar Kartikeya Dwivedi
a923819fb2 bpf: Treat first argument as return value for bpf_throw
In case of the default exception callback, change the behavior of
bpf_throw, where the passed cookie value is no longer ignored, but
is instead the return value of the default exception callback. As
such, we need to place restrictions on the value being passed into
bpf_throw in such a case, only allowing those permitted by the
check_return_code function.

Thus, bpf_throw can now control the return value of the program from
each call site without having the user install a custom exception
callback just to override the return value when an exception is thrown.

We also modify the hidden subprog instructions to now move BPF_REG_1 to
BPF_REG_0, so as to set the return value before exit in the default
callback.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
b62bf8a5e9 bpf: Perform CFG walk for exception callback
Since exception callbacks are not referenced using bpf_pseudo_func and
bpf_pseudo_call instructions, check_cfg traversal will never explore
instructions of the exception callback. Even after adding the subprog,
the program will then fail with a 'unreachable insn' error.

We thus need to begin walking from the start of the exception callback
again in check_cfg after a complete CFG traversal finishes, so as to
explore the CFG rooted at the exception callback.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
b9ae0c9dd0 bpf: Add support for custom exception callbacks
By default, the subprog generated by the verifier to handle a thrown
exception hardcodes a return value of 0. To allow user-defined logic
and modification of the return value when an exception is thrown,
introduce the 'exception_callback:' declaration tag, which marks a
callback as the default exception handler for the program.

The format of the declaration tag is 'exception_callback:<value>', where
<value> is the name of the exception callback. Each main program can be
tagged using this BTF declaratiion tag to associate it with an exception
callback. In case the tag is absent, the default callback is used.

As such, the exception callback cannot be modified at runtime, only set
during verification.

Allowing modification of the callback for the current program execution
at runtime leads to issues when the programs begin to nest, as any
per-CPU state maintaing this information will have to be saved and
restored. We don't want it to stay in bpf_prog_aux as this takes a
global effect for all programs. An alternative solution is spilling
the callback pointer at a known location on the program stack on entry,
and then passing this location to bpf_throw as a parameter.

However, since exceptions are geared more towards a use case where they
are ideally never invoked, optimizing for this use case and adding to
the complexity has diminishing returns.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
aaa619ebcc bpf: Refactor check_btf_func and split into two phases
This patch splits the check_btf_info's check_btf_func check into two
separate phases.  The first phase sets up the BTF and prepares
func_info, but does not perform any validation of required invariants
for subprogs just yet. This is left to the second phase, which happens
where check_btf_info executes currently, and performs the line_info and
CO-RE relocation.

The reason to perform this split is to obtain the userspace supplied
func_info information before we perform the add_subprog call, where we
would now require finding and adding subprogs that may not have a
bpf_pseudo_call or bpf_pseudo_func instruction in the program.

We require this as we want to enable userspace to supply exception
callbacks that can override the default hidden subprogram generated by
the verifier (which performs a hardcoded action). In such a case, the
exception callback may never be referenced in an instruction, but will
still be suitably annotated (by way of BTF declaration tags). For
finding this exception callback, we would require the program's BTF
information, and the supplied func_info information which maps BTF type
IDs to subprograms.

Since the exception callback won't actually be referenced through
instructions, later checks in check_cfg and do_check_subprogs will not
verify the subprog. This means that add_subprog needs to add them in the
add_subprog_and_kfunc phase before we move forward, which is why the BTF
and func_info are required at that point.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-6-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
f18b03faba bpf: Implement BPF exceptions
This patch implements BPF exceptions, and introduces a bpf_throw kfunc
to allow programs to throw exceptions during their execution at runtime.
A bpf_throw invocation is treated as an immediate termination of the
program, returning back to its caller within the kernel, unwinding all
stack frames.

This allows the program to simplify its implementation, by testing for
runtime conditions which the verifier has no visibility into, and assert
that they are true. In case they are not, the program can simply throw
an exception from the other branch.

BPF exceptions are explicitly *NOT* an unlikely slowpath error handling
primitive, and this objective has guided design choices of the
implementation of the them within the kernel (with the bulk of the cost
for unwinding the stack offloaded to the bpf_throw kfunc).

The implementation of this mechanism requires use of add_hidden_subprog
mechanism introduced in the previous patch, which generates a couple of
instructions to move R1 to R0 and exit. The JIT then rewrites the
prologue of this subprog to take the stack pointer and frame pointer as
inputs and reset the stack frame, popping all callee-saved registers
saved by the main subprog. The bpf_throw function then walks the stack
at runtime, and invokes this exception subprog with the stack and frame
pointers as parameters.

Reviewers must take note that currently the main program is made to save
all callee-saved registers on x86_64 during entry into the program. This
is because we must do an equivalent of a lightweight context switch when
unwinding the stack, therefore we need the callee-saved registers of the
caller of the BPF program to be able to return with a sane state.

Note that we have to additionally handle r12, even though it is not used
by the program, because when throwing the exception the program makes an
entry into the kernel which could clobber r12 after saving it on the
stack. To be able to preserve the value we received on program entry, we
push r12 and restore it from the generated subprogram when unwinding the
stack.

For now, bpf_throw invocation fails when lingering resources or locks
exist in that path of the program. In a future followup, bpf_throw will
be extended to perform frame-by-frame unwinding to release lingering
resources for each stack frame, removing this limitation.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
335d1c5b54 bpf: Implement support for adding hidden subprogs
Introduce support in the verifier for generating a subprogram and
include it as part of a BPF program dynamically after the do_check phase
is complete. The first user will be the next patch which generates
default exception callbacks if none are set for the program. The phase
of invocation will be do_misc_fixups. Note that this is an internal
verifier function, and should be used with instruction blocks which
uphold the invariants stated in check_subprogs.

Since these subprogs are always appended to the end of the instruction
sequence of the program, it becomes relatively inexpensive to do the
related adjustments to the subprog_info of the program. Only the fake
exit subprogram is shifted forward, making room for our new subprog.

This is useful to insert a new subprogram, get it JITed, and obtain its
function pointer. The next patch will use this functionality to insert a
default exception callback which will be invoked after unwinding the
stack.

Note that these added subprograms are invisible to userspace, and never
reported in BPF_OBJ_GET_INFO_BY_ID etc. For now, only a single
subprogram is supported, but more can be easily supported in the future.

To this end, two function counts are introduced now, the existing
func_cnt, and real_func_cnt, the latter including hidden programs. This
allows us to conver the JIT code to use the real_func_cnt for management
of resources while syscall path continues working with existing
func_cnt.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
Kumar Kartikeya Dwivedi
fd5d27b701 arch/x86: Implement arch_bpf_stack_walk
The plumbing for offline unwinding when we throw an exception in
programs would require walking the stack, hence introduce a new
arch_bpf_stack_walk function. This is provided when the JIT supports
exceptions, i.e. bpf_jit_supports_exceptions is true. The arch-specific
code is really minimal, hence it should be straightforward to extend
this support to other architectures as well, as it reuses the logic of
arch_stack_walk, but allowing access to unwind_state data.

Once the stack pointer and frame pointer are known for the main subprog
during the unwinding, we know the stack layout and location of any
callee-saved registers which must be restored before we return back to
the kernel. This handling will be added in the subsequent patches.

Note that while we primarily unwind through BPF frames, which are
effectively CONFIG_UNWINDER_FRAME_POINTER, we still need one of this or
CONFIG_UNWINDER_ORC to be able to unwind through the bpf_throw frame
from which we begin walking the stack. We also require both sp and bp
(stack and frame pointers) from the unwind_state structure, which are
only available when one of these two options are enabled.

Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230912233214.1518551-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-16 09:34:21 -07:00
David S. Miller
1612cc4b14 Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Alexei Starovoitov says:

====================

The following pull-request contains BPF updates for your *net* tree.

We've added 21 non-merge commits during the last 8 day(s) which contain
a total of 21 files changed, 450 insertions(+), 36 deletions(-).

The main changes are:

1) Adjust bpf_mem_alloc buckets to match ksize(), from Hou Tao.

2) Check whether override is allowed in kprobe mult, from Jiri Olsa.

3) Fix btf_id symbol generation with ld.lld, from Jiri and Nick.

4) Fix potential deadlock when using queue and stack maps from NMI, from Toke Høiland-Jørgensen.

Please consider pulling these changes from:

  git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf.git

Thanks a lot!

Also thanks to reporters, reviewers and testers of commits in this pull-request:

Alan Maguire, Biju Das, Björn Töpel, Dan Carpenter, Daniel Borkmann,
Eduard Zingerman, Hsin-Wei Hung, Marcus Seyfarth, Nathan Chancellor,
Satya Durga Srinivasu Prabhala, Song Liu, Stephen Rothwell
====================

Signed-off-by: David S. Miller <davem@davemloft.net>
2023-09-16 11:16:00 +01:00
Linus Torvalds
4eb2bd2475 Power management updates for 6.6-rc2
Fix the handling of block devices in the test_resume mode of
 hibernation (Chen Yu).
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Merge tag 'pm-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm

Pull power management fixes from Rafael Wysocki:
 "Fix the handling of block devices in the test_resume mode of
  hibernation (Chen Yu)"

* tag 'pm-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
  PM: hibernate: Fix the exclusive get block device in test_resume mode
  PM: hibernate: Rename function parameter from snapshot_test to exclusive
2023-09-15 15:11:53 -07:00
Larysa Zaremba
9b2b86332a bpf: Allow to use kfunc XDP hints and frags together
There is no fundamental reason, why multi-buffer XDP and XDP kfunc RX hints
cannot coexist in a single program.

Allow those features to be used together by modifying the flags condition
for dev-bound-only programs, segments are still prohibited for fully
offloaded programs, hence additional check.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/CAKH8qBuzgtJj=OKMdsxEkyML36VsAuZpcrsXcyqjdKXSJCBq=Q@mail.gmail.com/
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Larysa Zaremba <larysa.zaremba@intel.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230915083914.65538-1-larysa.zaremba@intel.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-15 11:39:46 -07:00
Stanislav Fomichev
a9c2a60854 bpf: expose information about supported xdp metadata kfunc
Add new xdp-rx-metadata-features member to netdev netlink
which exports a bitmask of supported kfuncs. Most of the patch
is autogenerated (headers), the only relevant part is netdev.yaml
and the changes in netdev-genl.c to marshal into netlink.

Example output on veth:

$ ip link add veth0 type veth peer name veth1 # ifndex == 12
$ ./tools/net/ynl/samples/netdev 12

Select ifc ($ifindex; or 0 = dump; or -2 ntf check): 12
   veth1[12]    xdp-features (23): basic redirect rx-sg xdp-rx-metadata-features (3): timestamp hash xdp-zc-max-segs=0

Cc: netdev@vger.kernel.org
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230913171350.369987-3-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-15 11:26:58 -07:00
Stanislav Fomichev
fc45c5b642 bpf: make it easier to add new metadata kfunc
No functional changes.

Instead of having hand-crafted code in bpf_dev_bound_resolve_kfunc,
move kfunc <> xmo handler relationship into XDP_METADATA_KFUNC_xxx.
This way, any time new kfunc is added, we don't have to touch
bpf_dev_bound_resolve_kfunc.

Also document XDP_METADATA_KFUNC_xxx arguments since we now have
more than two and it might be confusing what is what.

Cc: netdev@vger.kernel.org
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230913171350.369987-2-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-15 11:26:58 -07:00
Jiri Olsa
57eb5e1c5c bpf: Fix uprobe_multi get_pid_task error path
Dan reported Smatch static checker warning due to missing error
value set in uprobe multi link's get_pid_task error path.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/bpf/c5ffa7c0-6b06-40d5-aca2-63833b5cd9af@moroto.mountain/
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reviewed-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230915101420.1193800-1-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-15 10:32:40 -07:00
Hou Tao
dca7acd84e bpf: Skip unit_size checking for global per-cpu allocator
For global per-cpu allocator, the size of free object in free list
doesn't match with unit_size and now there is no way to get the size of
per-cpu pointer saved in free object, so just skip the checking.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Closes: https://lore.kernel.org/bpf/20230913133436.0eeec4cb@canb.auug.org.au/
Signed-off-by: Hou Tao <houtao1@huawei.com>
Tested-by: Biju Das <biju.das.jz@bp.renesas.com>
Link: https://lore.kernel.org/r/20230913135943.3137292-1-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-15 10:22:24 -07:00
Lukas Wunner
cccd328165 panic: Reenable preemption in WARN slowpath
Commit:

  5a5d7e9bad ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG")

amended warn_slowpath_fmt() to disable preemption until the WARN splat
has been emitted.

However the commit neglected to reenable preemption in the !fmt codepath,
i.e. when a WARN splat is emitted without additional format string.

One consequence is that users may see more splats than intended.  E.g. a
WARN splat emitted in a work item results in at least two extra splats:

  BUG: workqueue leaked lock or atomic
  (emitted by process_one_work())

  BUG: scheduling while atomic
  (emitted by worker_thread() -> schedule())

Ironically the point of the commit was to *avoid* extra splats. ;)

Fix it.

Fixes: 5a5d7e9bad ("cpuidle: lib/bug: Disable rcu_is_watching() during WARN/BUG")
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/3ec48fde01e4ee6505f77908ba351bad200ae3d1.1694763684.git.lukas@wunner.de
2023-09-15 11:28:08 +02:00
Song Liu
5c04433daf bpf: Charge modmem for struct_ops trampoline
Current code charges modmem for regular trampoline, but not for struct_ops
trampoline. Add bpf_jit_[charge|uncharge]_modmem() to struct_ops so the
trampoline is charged in both cases.

Signed-off-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/r/20230914222542.2986059-1-song@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-14 15:30:45 -07:00
Linus Torvalds
99214f6778 Tracing fixes for 6.6:
- Add missing LOCKDOWN checks for eventfs callers
   When LOCKDOWN is active for tracing, it causes inconsistent state
   when some functions succeed and others fail.
 
 - Use dput() to free the top level eventfs descriptor
   There was a race between accesses and freeing it.
 
 - Fix a long standing bug that eventfs exposed due to changing timings
   by dynamically creating files. That is, If a event file is opened
   for an instance, there's nothing preventing the instance from being
   removed which will make accessing the files cause use-after-free bugs.
 
 - Fix a ring buffer race that happens when iterating over the ring
   buffer while writers are active. Check to make sure not to read
   the event meta data if it's beyond the end of the ring buffer sub buffer.
 
 - Fix the print trigger that disappeared because the test to create it
   was looking for the event dir field being filled, but now it has the
   "ef" field filled for the eventfs structure.
 
 - Remove the unused "dir" field from the event structure.
 
 - Fix the order of the trace_dynamic_info as it had it backwards for the
   offset and len fields for which one was for which endianess.
 
 - Fix NULL pointer dereference with eventfs_remove_rec()
   If an allocation fails in one of the eventfs_add_*() functions,
   the caller of it in event_subsystem_dir() or event_create_dir()
   assigns the result to the structure. But it's assigning the ERR_PTR
   and not NULL. This was passed to eventfs_remove_rec() which expects
   either a good pointer or a NULL, not ERR_PTR. The fix is to not
   assign the ERR_PTR to the structure, but to keep it NULL on error.
 
 - Fix list_for_each_rcu() to use list_for_each_srcu() in
   dcache_dir_open_wrapper(). One iteration of the code used RCU
   but because it had to call sleepable code, it had to be changed
   to use SRCU, but one of the iterations was missed.
 
 - Fix synthetic event print function to use "as_u64" instead of
   passing in a pointer to the union. To fix big/little endian issues,
   the u64 that represented several types was turned into a union to
   define the types properly.
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Merge tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull tracing fixes from Steven Rostedt:

 - Add missing LOCKDOWN checks for eventfs callers

   When LOCKDOWN is active for tracing, it causes inconsistent state
   when some functions succeed and others fail.

 - Use dput() to free the top level eventfs descriptor

   There was a race between accesses and freeing it.

 - Fix a long standing bug that eventfs exposed due to changing timings
   by dynamically creating files. That is, If a event file is opened for
   an instance, there's nothing preventing the instance from being
   removed which will make accessing the files cause use-after-free
   bugs.

 - Fix a ring buffer race that happens when iterating over the ring
   buffer while writers are active. Check to make sure not to read the
   event meta data if it's beyond the end of the ring buffer sub buffer.

 - Fix the print trigger that disappeared because the test to create it
   was looking for the event dir field being filled, but now it has the
   "ef" field filled for the eventfs structure.

 - Remove the unused "dir" field from the event structure.

 - Fix the order of the trace_dynamic_info as it had it backwards for
   the offset and len fields for which one was for which endianess.

 - Fix NULL pointer dereference with eventfs_remove_rec()

   If an allocation fails in one of the eventfs_add_*() functions, the
   caller of it in event_subsystem_dir() or event_create_dir() assigns
   the result to the structure. But it's assigning the ERR_PTR and not
   NULL. This was passed to eventfs_remove_rec() which expects either a
   good pointer or a NULL, not ERR_PTR. The fix is to not assign the
   ERR_PTR to the structure, but to keep it NULL on error.

 - Fix list_for_each_rcu() to use list_for_each_srcu() in
   dcache_dir_open_wrapper(). One iteration of the code used RCU but
   because it had to call sleepable code, it had to be changed to use
   SRCU, but one of the iterations was missed.

 - Fix synthetic event print function to use "as_u64" instead of passing
   in a pointer to the union. To fix big/little endian issues, the u64
   that represented several types was turned into a union to define the
   types properly.

* tag 'trace-v6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  eventfs: Fix the NULL pointer dereference bug in eventfs_remove_rec()
  tracefs/eventfs: Use list_for_each_srcu() in dcache_dir_open_wrapper()
  tracing/synthetic: Print out u64 values properly
  tracing/synthetic: Fix order of struct trace_dynamic_info
  selftests/ftrace: Fix dependencies for some of the synthetic event tests
  tracing: Remove unused trace_event_file dir field
  tracing: Use the new eventfs descriptor for print trigger
  ring-buffer: Do not attempt to read past "commit"
  tracefs/eventfs: Free top level files on removal
  ring-buffer: Avoid softlockup in ring_buffer_resize()
  tracing: Have event inject files inc the trace array ref count
  tracing: Have option files inc the trace array ref count
  tracing: Have current_trace inc the trace array ref count
  tracing: Have tracing_max_latency inc the trace array ref count
  tracing: Increase trace array ref count on enable and filter files
  tracefs/eventfs: Use dput to free the toplevel events directory
  tracefs/eventfs: Add missing lockdown checks
  tracefs: Add missing lockdown check to tracefs_create_dir()
2023-09-13 11:30:11 -07:00
Tim Chen
450e749707 sched/fair: Fix SMT4 group_smt_balance handling
For SMT4, any group with more than 2 tasks will be marked as
group_smt_balance. Retain the behaviour of group_has_spare by marking
the busiest group as the group which has the least number of idle_cpus.

Also, handle rounding effect of adding (ncores_local + ncores_busy) when
the local is fully idle and busy group imbalance is less than 2 tasks.
Local group should try to pull at least 1 task in this case so imbalance
should be set to 2 instead.

Fixes: fee1759e4f ("sched/fair: Determine active load balance for SMT sched groups")
Acked-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: http://lkml.kernel.org/r/6cd1633036bb6b651af575c32c2a9608a106702c.camel@linux.intel.com
2023-09-13 15:03:06 +02:00
Ross Lagerwall
a6a241764f swiotlb: use the calculated number of areas
Commit 8ac0406335 ("swiotlb: reduce the number of areas to match
actual memory pool size") calculated the reduced number of areas in
swiotlb_init_remap() but didn't actually use the value. Replace usage of
default_nareas accordingly.

Fixes: 8ac0406335 ("swiotlb: reduce the number of areas to match actual memory pool size")
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
2023-09-13 09:13:15 -03:00
Randy Dunlap
214bfd267f bpf, cgroup: fix multiple kernel-doc warnings
Fix missing or extra function parameter kernel-doc warnings
in cgroup.c:

kernel/bpf/cgroup.c:1359: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_skb'
kernel/bpf/cgroup.c:1359: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_skb'
kernel/bpf/cgroup.c:1439: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sk'
kernel/bpf/cgroup.c:1439: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sk'
kernel/bpf/cgroup.c:1467: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sock_addr'
kernel/bpf/cgroup.c:1467: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sock_addr'
kernel/bpf/cgroup.c:1512: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sock_ops'
kernel/bpf/cgroup.c:1512: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sock_ops'
kernel/bpf/cgroup.c:1685: warning: Excess function parameter 'type' description in '__cgroup_bpf_run_filter_sysctl'
kernel/bpf/cgroup.c:1685: warning: Function parameter or member 'atype' not described in '__cgroup_bpf_run_filter_sysctl'
kernel/bpf/cgroup.c:795: warning: Excess function parameter 'type' description in '__cgroup_bpf_replace'
kernel/bpf/cgroup.c:795: warning: Function parameter or member 'new_prog' not described in '__cgroup_bpf_replace'

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: bpf@vger.kernel.org
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230912060812.1715-1-rdunlap@infradead.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12 13:19:07 -07:00
Christophe JAILLET
a8f1257286 bpf: Fix a erroneous check after snprintf()
snprintf() does not return negative error code on error, it returns the
number of characters which *would* be generated for the given input.

Fix the error handling check.

Fixes: 57539b1c0a ("bpf: Enable annotating trusted nested pointers")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/393bdebc87b22563c08ace094defa7160eb7a6c0.1694190795.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12 13:15:46 -07:00
Leon Hwang
2b5dcb31a1 bpf, x64: Fix tailcall infinite loop
From commit ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall
handling in JIT"), the tailcall on x64 works better than before.

From commit e411901c0b ("bpf: allow for tailcalls in BPF subprograms
for x64 JIT"), tailcall is able to run in BPF subprograms on x64.

From commit 5b92a28aae ("bpf: Support attaching tracing BPF program
to other BPF programs"), BPF program is able to trace other BPF programs.

How about combining them all together?

1. FENTRY/FEXIT on a BPF subprogram.
2. A tailcall runs in the BPF subprogram.
3. The tailcall calls the subprogram's caller.

As a result, a tailcall infinite loop comes up. And the loop would halt
the machine.

As we know, in tail call context, the tail_call_cnt propagates by stack
and rax register between BPF subprograms. So do in trampolines.

Fixes: ebf7d1f508 ("bpf, x64: rework pro/epilogue and tailcall handling in JIT")
Fixes: e411901c0b ("bpf: allow for tailcalls in BPF subprograms for x64 JIT")
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Leon Hwang <hffilwlqm@gmail.com>
Link: https://lore.kernel.org/r/20230912150442.2009-3-hffilwlqm@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-12 13:06:12 -07:00
Jinjie Ruan
c8414dab16 eventfs: Fix the NULL pointer dereference bug in eventfs_remove_rec()
Inject fault while probing btrfs.ko, if kstrdup() fails in
eventfs_prepare_ef() in eventfs_add_dir(), it will return ERR_PTR
to assign file->ef. But the eventfs_remove() check NULL in
trace_module_remove_events(), which causes the below NULL
pointer dereference.

As both Masami and Steven suggest, allocater side should handle the
error carefully and remove it, so fix the places where it failed.

 Could not create tracefs 'raid56_write' directory
 Btrfs loaded, zoned=no, fsverity=no
 Unable to handle kernel NULL pointer dereference at virtual address 000000000000001c
 Mem abort info:
   ESR = 0x0000000096000004
   EC = 0x25: DABT (current EL), IL = 32 bits
   SET = 0, FnV = 0
   EA = 0, S1PTW = 0
   FSC = 0x04: level 0 translation fault
 Data abort info:
   ISV = 0, ISS = 0x00000004, ISS2 = 0x00000000
   CM = 0, WnR = 0, TnD = 0, TagAccess = 0
   GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0
 user pgtable: 4k pages, 48-bit VAs, pgdp=0000000102544000
 [000000000000001c] pgd=0000000000000000, p4d=0000000000000000
 Internal error: Oops: 0000000096000004 [#1] PREEMPT SMP
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Modules linked in: btrfs(-) libcrc32c xor xor_neon raid6_pq cfg80211 rfkill 8021q garp mrp stp llc ipv6 [last unloaded: btrfs]
 CPU: 15 PID: 1343 Comm: rmmod Tainted: G                 N 6.5.0+ #40
 Hardware name: linux,dummy-virt (DT)
 pstate: 80000005 (Nzcv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
 pc : eventfs_remove_rec+0x24/0xc0
 lr : eventfs_remove+0x68/0x1d8
 sp : ffff800082d63b60
 x29: ffff800082d63b60 x28: ffffb84b80ddd00c x27: ffffb84b3054ba40
 x26: 0000000000000002 x25: ffff800082d63bf8 x24: ffffb84b8398e440
 x23: ffffb84b82af3000 x22: dead000000000100 x21: dead000000000122
 x20: ffff800082d63bf8 x19: fffffffffffffff4 x18: ffffb84b82508820
 x17: 0000000000000000 x16: 0000000000000000 x15: 000083bc876a3166
 x14: 000000000000006d x13: 000000000000006d x12: 0000000000000000
 x11: 0000000000000001 x10: 00000000000017e0 x9 : 0000000000000001
 x8 : 0000000000000000 x7 : 0000000000000000 x6 : ffffb84b84289804
 x5 : 0000000000000000 x4 : 9696969696969697 x3 : ffff33a5b7601f38
 x2 : 0000000000000000 x1 : ffff800082d63bf8 x0 : fffffffffffffff4
 Call trace:
  eventfs_remove_rec+0x24/0xc0
  eventfs_remove+0x68/0x1d8
  remove_event_file_dir+0x88/0x100
  event_remove+0x140/0x15c
  trace_module_notify+0x1fc/0x230
  notifier_call_chain+0x98/0x17c
  blocking_notifier_call_chain+0x4c/0x74
  __arm64_sys_delete_module+0x1a4/0x298
  invoke_syscall+0x44/0x100
  el0_svc_common.constprop.1+0x68/0xe0
  do_el0_svc+0x1c/0x28
  el0_svc+0x3c/0xc4
  el0t_64_sync_handler+0xa0/0xc4
  el0t_64_sync+0x174/0x178
 Code: 5400052c a90153b3 aa0003f3 aa0103f4 (f9401400)
 ---[ end trace 0000000000000000 ]---
 Kernel panic - not syncing: Oops: Fatal exception
 SMP: stopping secondary CPUs
 Dumping ftrace buffer:
    (ftrace buffer empty)
 Kernel Offset: 0x384b00c00000 from 0xffff800080000000
 PHYS_OFFSET: 0xffffcc5b80000000
 CPU features: 0x88000203,3c020000,1000421b
 Memory Limit: none
 Rebooting in 1 seconds..

Link: https://lore.kernel.org/linux-trace-kernel/20230912134752.1838524-1-ruanjinjie@huawei.com
Link: https://lore.kernel.org/all/20230912025808.668187-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230911052818.1020547-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230909072817.182846-1-ruanjinjie@huawei.com/
Link: https://lore.kernel.org/all/20230908074816.3724716-1-ruanjinjie@huawei.com/

Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 5bdcd5f533 ("eventfs: Implement removal of meta data from eventfs")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Suggested-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Suggested-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-12 09:57:01 -04:00
Chen Yu
148b6f4cc3 PM: hibernate: Fix the exclusive get block device in test_resume mode
Commit 5904de0d73 ("PM: hibernate: Do not get block device exclusively
in test_resume mode") fixes a hibernation issue under test_resume mode.
That commit is supposed to open the block device in non-exclusive mode
when in test_resume. However the code does the opposite, which is against
its description.

In summary, the swap device is only opened exclusively by swsusp_check()
with its corresponding *close(), and must be in non test_resume mode.
This is to avoid the race condition that different processes scribble the
device at the same time. All the other cases should use non-exclusive mode.

Fix it by really disabling exclusive mode under test_resume.

Fixes: 5904de0d73 ("PM: hibernate: Do not get block device exclusively in test_resume mode")
Closes: https://lore.kernel.org/lkml/000000000000761f5f0603324129@google.com/
Reported-by: Pengfei Xu <pengfei.xu@intel.com>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Tested-by: Chenzhou Feng <chenzhoux.feng@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-09-12 11:45:15 +02:00
Chen Yu
40d84e198b PM: hibernate: Rename function parameter from snapshot_test to exclusive
Several functions reply on snapshot_test to decide whether to
open the resume device exclusively. However there is no strict
connection between the snapshot_test and the open mode. Rename
the 'snapshot_test' input parameter to 'exclusive' to better reflect
the use case.

No functional change is expected.

Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2023-09-12 11:45:15 +02:00
Eduard Zingerman
1a49f4195d bpf: Avoid dummy bpf_offload_netdev in __bpf_prog_dev_bound_init
Fix for a bug observable under the following sequence of events:
1. Create a network device that does not support XDP offload.
2. Load a device bound XDP program with BPF_F_XDP_DEV_BOUND_ONLY flag
   (such programs are not offloaded).
3. Load a device bound XDP program with zero flags
   (such programs are offloaded).

At step (2) __bpf_prog_dev_bound_init() associates with device (1)
a dummy bpf_offload_netdev struct with .offdev field set to NULL.
At step (3) __bpf_prog_dev_bound_init() would reuse dummy struct
allocated at step (2).
However, downstream usage of the bpf_offload_netdev assumes that
.offdev field can't be NULL, e.g. in bpf_prog_offload_verifier_prep().

Adjust __bpf_prog_dev_bound_init() to require bpf_offload_netdev
with non-NULL .offdev for offloaded BPF programs.

Fixes: 2b3486bc2d ("bpf: Introduce device-bound XDP programs")
Reported-by: syzbot+291100dcb32190ec02a8@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/bpf/000000000000d97f3c060479c4f8@google.com/
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230912005539.2248244-2-eddyz87@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-09-11 22:06:06 -07:00
Toke Høiland-Jørgensen
a34a9f1a19 bpf: Avoid deadlock when using queue and stack maps from NMI
Sysbot discovered that the queue and stack maps can deadlock if they are
being used from a BPF program that can be called from NMI context (such as
one that is attached to a perf HW counter event). To fix this, add an
in_nmi() check and use raw_spin_trylock() in NMI context, erroring out if
grabbing the lock fails.

Fixes: f1a2e44a3a ("bpf: add queue and stack maps")
Reported-by: Hsin-Wei Hung <hsinweih@uci.edu>
Tested-by: Hsin-Wei Hung <hsinweih@uci.edu>
Co-developed-by: Hsin-Wei Hung <hsinweih@uci.edu>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://lore.kernel.org/r/20230911132815.717240-1-toke@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11 19:04:49 -07:00
Tero Kristo
62663b8496 tracing/synthetic: Print out u64 values properly
The synth traces incorrectly print pointer to the synthetic event values
instead of the actual value when using u64 type. Fix by addressing the
contents of the union properly.

Link: https://lore.kernel.org/linux-trace-kernel/20230911141704.3585965-1-tero.kristo@linux.intel.com

Fixes: ddeea494a1 ("tracing/synthetic: Use union instead of casts")
Cc: stable@vger.kernel.org
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-11 18:23:10 -04:00
Hou Tao
c930472552 bpf: Ensure unit_size is matched with slab cache object size
Add extra check in bpf_mem_alloc_init() to ensure the unit_size of
bpf_mem_cache is matched with the object_size of underlying slab cache.
If these two sizes are unmatched, print a warning once and return
-EINVAL in bpf_mem_alloc_init(), so the mismatch can be found early and
the potential issue can be prevented.

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230908133923.2675053-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11 12:41:37 -07:00
Hou Tao
b1d53958b6 bpf: Don't prefill for unused bpf_mem_cache
When the unit_size of a bpf_mem_cache is unmatched with the object_size
of the underlying slab cache, the bpf_mem_cache will not be used, and
the allocation will be redirected to a bpf_mem_cache with a bigger
unit_size instead, so there is no need to prefill for these
unused bpf_mem_caches.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230908133923.2675053-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11 12:41:37 -07:00
Hou Tao
d52b59315b bpf: Adjust size_index according to the value of KMALLOC_MIN_SIZE
The following warning was reported when running "./test_progs -a
link_api -a linked_list" on a RISC-V QEMU VM:

  ------------[ cut here ]------------
  WARNING: CPU: 3 PID: 261 at kernel/bpf/memalloc.c:342 bpf_mem_refill
  Modules linked in: bpf_testmod(OE)
  CPU: 3 PID: 261 Comm: test_progs- ... 6.5.0-rc5-01743-gdcb152bb8328 #2
  Hardware name: riscv-virtio,qemu (DT)
  epc : bpf_mem_refill+0x1fc/0x206
   ra : irq_work_single+0x68/0x70
  epc : ffffffff801b1bc4 ra : ffffffff8015fe84 sp : ff2000000001be20
   gp : ffffffff82d26138 tp : ff6000008477a800 t0 : 0000000000046600
   t1 : ffffffff812b6ddc t2 : 0000000000000000 s0 : ff2000000001be70
   s1 : ff5ffffffffe8998 a0 : ff5ffffffffe8998 a1 : ff600003fef4b000
   a2 : 000000000000003f a3 : ffffffff80008250 a4 : 0000000000000060
   a5 : 0000000000000080 a6 : 0000000000000000 a7 : 0000000000735049
   s2 : ff5ffffffffe8998 s3 : 0000000000000022 s4 : 0000000000001000
   s5 : 0000000000000007 s6 : ff5ffffffffe8570 s7 : ffffffff82d6bd30
   s8 : 000000000000003f s9 : ffffffff82d2c5e8 s10: 000000000000ffff
   s11: ffffffff82d2c5d8 t3 : ffffffff81ea8f28 t4 : 0000000000000000
   t5 : ff6000008fd28278 t6 : 0000000000040000
  [<ffffffff801b1bc4>] bpf_mem_refill+0x1fc/0x206
  [<ffffffff8015fe84>] irq_work_single+0x68/0x70
  [<ffffffff8015feb4>] irq_work_run_list+0x28/0x36
  [<ffffffff8015fefa>] irq_work_run+0x38/0x66
  [<ffffffff8000828a>] handle_IPI+0x3a/0xb4
  [<ffffffff800a5c3a>] handle_percpu_devid_irq+0xa4/0x1f8
  [<ffffffff8009fafa>] generic_handle_domain_irq+0x28/0x36
  [<ffffffff800ae570>] ipi_mux_process+0xac/0xfa
  [<ffffffff8000a8ea>] sbi_ipi_handle+0x2e/0x88
  [<ffffffff8009fafa>] generic_handle_domain_irq+0x28/0x36
  [<ffffffff807ee70e>] riscv_intc_irq+0x36/0x4e
  [<ffffffff812b5d3a>] handle_riscv_irq+0x54/0x86
  [<ffffffff812b6904>] do_irq+0x66/0x98
  ---[ end trace 0000000000000000 ]---

The warning is due to WARN_ON_ONCE(tgt->unit_size != c->unit_size) in
free_bulk(). The direct reason is that a object is allocated and
freed by bpf_mem_caches with different unit_size.

The root cause is that KMALLOC_MIN_SIZE is 64 and there is no 96-bytes
slab cache in the specific VM. When linked_list test allocates a
72-bytes object through bpf_obj_new(), bpf_global_ma will allocate it
from a bpf_mem_cache with 96-bytes unit_size, but this bpf_mem_cache is
backed by 128-bytes slab cache. When the object is freed, bpf_mem_free()
uses ksize() to choose the corresponding bpf_mem_cache. Because the
object is allocated from 128-bytes slab cache, ksize() returns 128,
bpf_mem_free() chooses a 128-bytes bpf_mem_cache to free the object and
triggers the warning.

A similar warning will also be reported when using CONFIG_SLAB instead
of CONFIG_SLUB in a x86-64 kernel. Because CONFIG_SLUB defines
KMALLOC_MIN_SIZE as 8 but CONFIG_SLAB defines KMALLOC_MIN_SIZE as 32.

An alternative fix is to use kmalloc_size_round() in bpf_mem_alloc() to
choose a bpf_mem_cache which has the same unit_size with the backing
slab cache, but it may introduce performance degradation, so fix the
warning by adjusting the indexes in size_index according to the value of
KMALLOC_MIN_SIZE just like setup_kmalloc_cache_index_table() does.

Fixes: 822fb26bdb ("bpf: Add a hint to allocated objects.")
Reported-by: Björn Töpel <bjorn@kernel.org>
Closes: https://lore.kernel.org/bpf/87jztjmmy4.fsf@all.your.base.are.belong.to.us
Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230908133923.2675053-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-11 12:41:36 -07:00
Linus Torvalds
1b37a0a2d4 RISC-V Patches for the 6.6 Merge Window, Part 2 (try 2)
* The kernel now dynamically probes for misaligned access speed, as
   opposed to relying on a table of known implementations.
 * Support for non-coherent devices on systems using the Andes AX45MP
   core, including the RZ/Five SoCs.
 * Support for the V extension in ptrace(), again.
 * Support for KASLR.
 * Support for the BPF prog pack allocator in RISC-V.
 * A handful of bug fixes and cleanups.
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Merge tag 'riscv-for-linus-6.6-mw2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux

Pull more RISC-V updates from Palmer Dabbelt:

 - The kernel now dynamically probes for misaligned access speed, as
   opposed to relying on a table of known implementations.

 - Support for non-coherent devices on systems using the Andes AX45MP
   core, including the RZ/Five SoCs.

 - Support for the V extension in ptrace(), again.

 - Support for KASLR.

 - Support for the BPF prog pack allocator in RISC-V.

 - A handful of bug fixes and cleanups.

* tag 'riscv-for-linus-6.6-mw2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (25 commits)
  soc: renesas: Kconfig: For ARCH_R9A07G043 select the required configs if dependencies are met
  riscv: Kconfig.errata: Add dependency for RISCV_SBI in ERRATA_ANDES config
  riscv: Kconfig.errata: Drop dependency for MMU in ERRATA_ANDES_CMO config
  riscv: Kconfig: Select DMA_DIRECT_REMAP only if MMU is enabled
  bpf, riscv: use prog pack allocator in the BPF JIT
  riscv: implement a memset like function for text
  riscv: extend patch_text_nosync() for multiple pages
  bpf: make bpf_prog_pack allocator portable
  riscv: libstub: Implement KASLR by using generic functions
  libstub: Fix compilation warning for rv32
  arm64: libstub: Move KASLR handling functions to kaslr.c
  riscv: Dump out kernel offset information on panic
  riscv: Introduce virtual kernel mapping KASLR
  RISC-V: Add ptrace support for vectors
  soc: renesas: Kconfig: Select the required configs for RZ/Five SoC
  cache: Add L2 cache management for Andes AX45MP RISC-V core
  dt-bindings: cache: andestech,ax45mp-cache: Add DT binding documentation for L2 cache controller
  riscv: mm: dma-noncoherent: nonstandard cache operations support
  riscv: errata: Add Andes alternative ports
  riscv: asm: vendorid_list: Add Andes Technology to the vendors list
  ...
2023-09-09 14:25:11 -07:00
Linus Torvalds
474197a4f7 dma-mapping fixes for Linux 6.6
- move a dma-debug call that prints a message out from a lock that's
    causing problems with the lock order in serial drivers (Sergey Senozhatsky)
  - fix the CONFIG_DMA_NUMA_CMA Kconfig entry to have the right dependency
    on not default to y (Christoph Hellwig)
  - move an ifdef a bit to remove a __maybe_unused that seems to trip up
    some sensitivities (Christoph Hellwig)
  - revert a bogus check in the CMA allocator (Zhenhua Huang)
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Merge tag 'dma-mapping-6.6-2023-09-09' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - move a dma-debug call that prints a message out from a lock that's
   causing problems with the lock order in serial drivers (Sergey
   Senozhatsky)

 - fix the CONFIG_DMA_NUMA_CMA Kconfig entry to have the right
   dependency and not default to y (Christoph Hellwig)

 - move an ifdef a bit to remove a __maybe_unused that seems to trip up
   some sensitivities (Christoph Hellwig)

 - revert a bogus check in the CMA allocator (Zhenhua Huang)

* tag 'dma-mapping-6.6-2023-09-09' of git://git.infradead.org/users/hch/dma-mapping:
  Revert "dma-contiguous: check for memory region overlap"
  dma-pool: remove a __maybe_unused label in atomic_pool_expand
  dma-contiguous: fix the Kconfig entry for CONFIG_DMA_NUMA_CMA
  dma-debug: don't call __dma_entry_alloc_check_leak() under free_entries_lock
2023-09-09 11:41:22 -07:00
Steven Rostedt (Google)
6fdac58c56 tracing: Remove unused trace_event_file dir field
Now that eventfs structure is used to create the events directory via the
eventfs dynamically allocate code, the "dir" field of the trace_event_file
structure is no longer used. Remove it.

Link: https://lkml.kernel.org/r/20230908022001.580400115@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-08 23:13:02 -04:00
Steven Rostedt (Google)
1ef26d8b2c tracing: Use the new eventfs descriptor for print trigger
The check to create the print event "trigger" was using the obsolete "dir"
value of the trace_event_file to determine if it should create the trigger
or not. But that value will now be NULL because it uses the event file
descriptor.

Change it to test the "ef" field of the trace_event_file structure so that
the trace_marker "trigger" file appears again.

Link: https://lkml.kernel.org/r/20230908022001.371815239@goodmis.org

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ajay Kaher <akaher@vmware.com>
Fixes: 27152bceea ("eventfs: Move tracing/events to eventfs")
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-08 23:13:01 -04:00
Steven Rostedt (Google)
95a404bd60 ring-buffer: Do not attempt to read past "commit"
When iterating over the ring buffer while the ring buffer is active, the
writer can corrupt the reader. There's barriers to help detect this and
handle it, but that code missed the case where the last event was at the
very end of the page and has only 4 bytes left.

The checks to detect the corruption by the writer to reads needs to see the
length of the event. If the length in the first 4 bytes is zero then the
length is stored in the second 4 bytes. But if the writer is in the process
of updating that code, there's a small window where the length in the first
4 bytes could be zero even though the length is only 4 bytes. That will
cause rb_event_length() to read the next 4 bytes which could happen to be off the
allocated page.

To protect against this, fail immediately if the next event pointer is
less than 8 bytes from the end of the commit (last byte of data), as all
events must be a minimum of 8 bytes anyway.

Link: https://lore.kernel.org/all/20230905141245.26470-1-Tze-nan.Wu@mediatek.com/
Link: https://lore.kernel.org/linux-trace-kernel/20230907122820.0899019c@gandalf.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Reported-by: Tze-nan Wu <Tze-nan.Wu@mediatek.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-08 23:12:19 -04:00
Jiri Olsa
41bc46c12a bpf: Add override check to kprobe multi link attach
Currently the multi_kprobe link attach does not check error
injection list for programs with bpf_override_return helper
and allows them to attach anywhere. Adding the missing check.

Fixes: 0dcac27254 ("bpf: Add multi kprobe link")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Alan Maguire <alan.maguire@oracle.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/bpf/20230907200652.926951-1-jolsa@kernel.org
2023-09-08 16:53:10 -07:00
Linus Torvalds
01a46efcd8 printk fixup for 6.6
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Merge tag 'printk-for-6.6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk fix from Petr Mladek:

 - Revert exporting symbols needed for dumping the raw printk buffer in
   panic().

   I pushed the export prematurely before the user was ready for merging
   into the mainline.

* tag 'printk-for-6.6-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  Revert "printk: export symbols for debug modules"
2023-09-08 12:13:01 -07:00
Palmer Dabbelt
77eea559ba
Merge patch series "bpf, riscv: use BPF prog pack allocator in BPF JIT"
Puranjay Mohan <puranjay12@gmail.com> says:

Here is some data to prove the V2 fixes the problem:

Without this series:
root@rv-selftester:~/src/kselftest/bpf# time ./test_tag
test_tag: OK (40945 tests)

real    7m47.562s
user    0m24.145s
sys     6m37.064s

With this series applied:
root@rv-selftester:~/src/selftest/bpf# time ./test_tag
test_tag: OK (40945 tests)

real    7m29.472s
user    0m25.865s
sys     6m18.401s

BPF programs currently consume a page each on RISCV. For systems with many BPF
programs, this adds significant pressure to instruction TLB. High iTLB pressure
usually causes slow down for the whole system.

Song Liu introduced the BPF prog pack allocator[1] to mitigate the above issue.
It packs multiple BPF programs into a single huge page. It is currently only
enabled for the x86_64 BPF JIT.

I enabled this allocator on the ARM64 BPF JIT[2]. It is being reviewed now.

This patch series enables the BPF prog pack allocator for the RISCV BPF JIT.

======================================================
Performance Analysis of prog pack allocator on RISCV64
======================================================

Test setup:
===========

Host machine: Debian GNU/Linux 11 (bullseye)
Qemu Version: QEMU emulator version 8.0.3 (Debian 1:8.0.3+dfsg-1)
u-boot-qemu Version: 2023.07+dfsg-1
opensbi Version: 1.3-1

To test the performance of the BPF prog pack allocator on RV, a stresser
tool[4] linked below was built. This tool loads 8 BPF programs on the system and
triggers 5 of them in an infinite loop by doing system calls.

The runner script starts 20 instances of the above which loads 8*20=160 BPF
programs on the system, 5*20=100 of which are being constantly triggered.
The script is passed a command which would be run in the above environment.

The script was run with following perf command:
./run.sh "perf stat -a \
        -e iTLB-load-misses \
        -e dTLB-load-misses  \
        -e dTLB-store-misses \
        -e instructions \
        --timeout 60000"

The output of the above command is discussed below before and after enabling the
BPF prog pack allocator.

The tests were run on qemu-system-riscv64 with 8 cpus, 16G memory. The rootfs
was created using Bjorn's riscv-cross-builder[5] docker container linked below.

Results
=======

Before enabling prog pack allocator:
------------------------------------

Performance counter stats for 'system wide':

           4939048      iTLB-load-misses
           5468689      dTLB-load-misses
            465234      dTLB-store-misses
     1441082097998      instructions

      60.045791200 seconds time elapsed

After enabling prog pack allocator:
-----------------------------------

Performance counter stats for 'system wide':

           3430035      iTLB-load-misses
           5008745      dTLB-load-misses
            409944      dTLB-store-misses
     1441535637988      instructions

      60.046296600 seconds time elapsed

Improvements in metrics
=======================

It was expected that the iTLB-load-misses would decrease as now a single huge
page is used to keep all the BPF programs compared to a single page for each
program earlier.

--------------------------------------------
The improvement in iTLB-load-misses: -30.5 %
--------------------------------------------

I repeated this expriment more than 100 times in different setups and the
improvement was always greater than 30%.

This patch series is boot tested on the Starfive VisionFive 2 board[6].
The performance analysis was not done on the board because it doesn't
expose iTLB-load-misses, etc. The stresser program was run on the board to test
the loading and unloading of BPF programs

[1] https://lore.kernel.org/bpf/20220204185742.271030-1-song@kernel.org/
[2] https://lore.kernel.org/all/20230626085811.3192402-1-puranjay12@gmail.com/
[3] https://lore.kernel.org/all/20230626085811.3192402-2-puranjay12@gmail.com/
[4] https://github.com/puranjaymohan/BPF-Allocator-Bench
[5] https://github.com/bjoto/riscv-cross-builder
[6] https://www.starfivetech.com/en/site/boards

* b4-shazam-merge:
  bpf, riscv: use prog pack allocator in the BPF JIT
  riscv: implement a memset like function for text
  riscv: extend patch_text_nosync() for multiple pages
  bpf: make bpf_prog_pack allocator portable

Link: https://lore.kernel.org/r/20230831131229.497941-1-puranjay12@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-08 11:25:25 -07:00
Oleg Nesterov
780aa8dfcb bpf: task_group_seq_get_next: simplify the "next tid" logic
Kill saved_tid. It looks ugly to update *tid and then restore the
previous value if __task_pid_nr_ns() returns 0. Change this code
to update *tid and common->pid_visiting once before return.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154656.GA24950@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:19 -07:00
Oleg Nesterov
0ee9808b0a bpf: task_group_seq_get_next: kill next_task
It only adds the unnecessary confusion and compicates the "retry" code.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154654.GA24945@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:19 -07:00
Oleg Nesterov
87abbf7a54 bpf: task_group_seq_get_next: fix the skip_if_dup_files check
Unless I am notally confused it is wrong. We are going to return or
skip next_task so we need to check next_task-files, not task->files.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154651.GA24940@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:19 -07:00
Oleg Nesterov
4981921350 bpf: task_group_seq_get_next: cleanup the usage of get/put_task_struct
get_pid_task() makes no sense, the code does put_task_struct() soon after.
Use find_task_by_pid_ns() instead of find_pid_ns + get_pid_task and kill
put_task_struct(), this allows to do get_task_struct() only once before
return.

While at it, kill the unnecessary "if (!pid)" check in the "if (!*tid)"
block, this matches the next usage of find_pid_ns() + get_pid_task() in
this function.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154649.GA24935@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:19 -07:00
Oleg Nesterov
1a00ef57d9 bpf: task_group_seq_get_next: cleanup the usage of next_thread()
1. find_pid_ns() + get_pid_task() under rcu_read_lock() guarantees that we
   can safely iterate the task->thread_group list. Even if this task exits
   right after get_pid_task() (or goto retry) and pid_alive() returns 0.

   Kill the unnecessary pid_alive() check.

2. next_thread() simply can't return NULL, kill the bogus "if (!next_task)"
   check.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230905154646.GA24928@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:19 -07:00
Hou Tao
62cf51cb0e bpf: Enable IRQ after irq_work_raise() completes in unit_free{_rcu}()
Both unit_free() and unit_free_rcu() invoke irq_work_raise() to free
freed objects back to slab and the invocation may also be preempted by
unit_alloc() and unit_alloc() may return NULL unexpectedly as shown in
the following case:

task A         task B

unit_free()
  // high_watermark = 48
  // free_cnt = 49 after free
  irq_work_raise()
    // mark irq work as IRQ_WORK_PENDING
    irq_work_claim()

               // task B preempts task A
               unit_alloc()
                 // free_cnt = 48 after alloc

               // does unit_alloc() 32-times
	       ......
	       // free_cnt = 16

	       unit_alloc()
	         // free_cnt = 15 after alloc
                 // irq work is already PENDING,
                 // so just return
                 irq_work_raise()

	       // does unit_alloc() 15-times
               ......
	       // free_cnt = 0

               unit_alloc()
                 // free_cnt = 0 before alloc
                 return NULL

Fix it by enabling IRQ after irq_work_raise() completes.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230901111954.1804721-3-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:19 -07:00
Hou Tao
566f6de3ce bpf: Enable IRQ after irq_work_raise() completes in unit_alloc()
When doing stress test for qp-trie, bpf_mem_alloc() returned NULL
unexpectedly because all qp-trie operations were initiated from
bpf syscalls and there was still available free memory. bpf_obj_new()
has the same problem as shown by the following selftest.

The failure is due to the preemption. irq_work_raise() will invoke
irq_work_claim() first to mark the irq work as pending and then inovke
__irq_work_queue_local() to raise an IPI. So when the current task
which is invoking irq_work_raise() is preempted by other task,
unit_alloc() may return NULL for preemption task as shown below:

task A         task B

unit_alloc()
  // low_watermark = 32
  // free_cnt = 31 after alloc
  irq_work_raise()
    // mark irq work as IRQ_WORK_PENDING
    irq_work_claim()

	       // task B preempts task A
	       unit_alloc()
	         // free_cnt = 30 after alloc
	         // irq work is already PENDING,
	         // so just return
	         irq_work_raise()
	       // does unit_alloc() 30-times
	       ......
	       unit_alloc()
	         // free_cnt = 0 before alloc
	         return NULL

Fix it by enabling IRQ after irq_work_raise() completes. An alternative
fix is using preempt_{disable|enable}_notrace() pair, but it may have
extra overhead. Another feasible fix is to only disable preemption or
IRQ before invoking irq_work_queue() and enable preemption or IRQ after
the invocation completes, but it can't handle the case when
c->low_watermark is 1.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230901111954.1804721-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:18 -07:00
Yonghong Song
5b221ecb3a bpf: Mark OBJ_RELEASE argument as MEM_RCU when possible
In previous selftests/bpf patch, we have
  p = bpf_percpu_obj_new(struct val_t);
  if (!p)
          goto out;

  p1 = bpf_kptr_xchg(&e->pc, p);
  if (p1) {
          /* race condition */
          bpf_percpu_obj_drop(p1);
  }

  p = e->pc;
  if (!p)
          goto out;

After bpf_kptr_xchg(), we need to re-read e->pc into 'p'.
This is due to that the second argument of bpf_kptr_xchg() is marked
OBJ_RELEASE and it will be marked as invalid after the call.
So after bpf_kptr_xchg(), 'p' is an unknown scalar,
and the bpf program needs to reread from the map value.

This patch checks if the 'p' has type MEM_ALLOC and MEM_PERCPU,
and if 'p' is RCU protected. If this is the case, 'p' can be marked
as MEM_RCU. MEM_ALLOC needs to be removed since 'p' is not
an owning reference any more. Such a change makes re-read
from the map value unnecessary.

Note that re-reading 'e->pc' after bpf_kptr_xchg() might get
a different value from 'p' if immediately before 'p = e->pc',
another cpu may do another bpf_kptr_xchg() and swap in another value
into 'e->pc'. If this is the case, then 'p = e->pc' may
get either 'p' or another value, and race condition already exists.
So removing direct re-reading seems fine too.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152816.2000760-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:18 -07:00
Yonghong Song
01cc55af93 bpf: Add bpf_this_cpu_ptr/bpf_per_cpu_ptr support for allocated percpu obj
The bpf helpers bpf_this_cpu_ptr() and bpf_per_cpu_ptr() are re-purposed
for allocated percpu objects. For an allocated percpu obj,
the reg type is 'PTR_TO_BTF_ID | MEM_PERCPU | MEM_RCU'.

The return type for these two re-purposed helpera is
'PTR_TO_MEM | MEM_RCU | MEM_ALLOC'.
The MEM_ALLOC allows that the per-cpu data can be read and written.

Since the memory allocator bpf_mem_alloc() returns
a ptr to a percpu ptr for percpu data, the first argument
of bpf_this_cpu_ptr() and bpf_per_cpu_ptr() is patched
with a dereference before passing to the helper func.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152749.1997202-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:17 -07:00
Yonghong Song
36d8bdf75a bpf: Add alloc/xchg/direct_access support for local percpu kptr
Add two new kfunc's, bpf_percpu_obj_new_impl() and
bpf_percpu_obj_drop_impl(), to allocate a percpu obj.
Two functions are very similar to bpf_obj_new_impl()
and bpf_obj_drop_impl(). The major difference is related
to percpu handling.

    bpf_rcu_read_lock()
    struct val_t __percpu_kptr *v = map_val->percpu_data;
    ...
    bpf_rcu_read_unlock()

For a percpu data map_val like above 'v', the reg->type
is set as
	PTR_TO_BTF_ID | MEM_PERCPU | MEM_RCU
if inside rcu critical section.

MEM_RCU marking here is similar to NON_OWN_REF as 'v'
is not a owning reference. But NON_OWN_REF is
trusted and typically inside the spinlock while
MEM_RCU is under rcu read lock. RCU is preferred here
since percpu data structures mean potential concurrent
access into its contents.

Also, bpf_percpu_obj_new_impl() is restricted such that
no pointers or special fields are allowed. Therefore,
the bpf_list_head and bpf_rb_root will not be supported
in this patch set to avoid potential memory leak issue
due to racing between bpf_obj_free_fields() and another
bpf_kptr_xchg() moving an allocated object to
bpf_list_head and bpf_rb_root.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152744.1996739-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:17 -07:00
Yonghong Song
55db92f42f bpf: Add BPF_KPTR_PERCPU as a field type
BPF_KPTR_PERCPU represents a percpu field type like below

  struct val_t {
    ... fields ...
  };
  struct t {
    ...
    struct val_t __percpu_kptr *percpu_data_ptr;
    ...
  };

where
  #define __percpu_kptr __attribute__((btf_type_tag("percpu_kptr")))

While BPF_KPTR_REF points to a trusted kernel object or a trusted
local object, BPF_KPTR_PERCPU points to a trusted local
percpu object.

This patch added basic support for BPF_KPTR_PERCPU
related to percpu_kptr field parsing, recording and free operations.
BPF_KPTR_PERCPU also supports the same map types
as BPF_KPTR_REF does.

Note that unlike a local kptr, it is possible that
a BPF_KTPR_PERCPU struct may not contain any
special fields like other kptr, bpf_spin_lock, bpf_list_head, etc.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152739.1996391-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:17 -07:00
Yonghong Song
41a5db8d81 bpf: Add support for non-fix-size percpu mem allocation
This is needed for later percpu mem allocation when the
allocation is done by bpf program. For such cases, a global
bpf_global_percpu_ma is added where a flexible allocation
size is needed.

Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20230827152734.1995725-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-09-08 08:42:17 -07:00
Zhenhua Huang
f875db4f20 Revert "dma-contiguous: check for memory region overlap"
This reverts commit 3fa6456ebe.

The Commit broke the CMA region creation through DT on arm64,
as showed below logs with "memblock=debug":
[    0.000000] memblock_phys_alloc_range: 41943040 bytes align=0x200000
from=0x0000000000000000 max_addr=0x00000000ffffffff
early_init_dt_alloc_reserved_memory_arch+0x34/0xa0
[    0.000000] memblock_reserve: [0x00000000fd600000-0x00000000ffdfffff]
memblock_alloc_range_nid+0xc0/0x19c
[    0.000000] Reserved memory: overlap with other memblock reserved region

>From call flow, region we defined in DT was always reserved before entering
into rmem_cma_setup. Also, rmem_cma_setup has one routine cma_init_reserved_mem
to ensure the region was reserved. Checking the region not reserved here seems
not correct.

early_init_fdt_scan_reserved_mem:
    fdt_scan_reserved_mem
        __reserved_mem_reserve_reg
		early_init_dt_reserve_memory
			memblock_reserve(using “reg” prop case)
        fdt_init_reserved_mem
		__reserved_mem_alloc_size
			*early_init_dt_alloc_reserved_memory_arch*
				memblock_reserve(dynamic alloc case)
        __reserved_mem_init_node
		rmem_cma_setup(region overlap check here should always fail)

Example DT can be used to reproduce issue:

    dump_mem: mem_dump_region {
            compatible = "shared-dma-pool";
            alloc-ranges = <0x0 0x00000000 0x0 0xffffffff>;
            reusable;
            size = <0 0x2800000>;
    };

Signed-off-by: Zhenhua Huang <quic_zhenhuah@quicinc.com>
2023-09-08 05:58:32 -03:00
Linus Torvalds
73be7fb14e Including fixes from netfilter and bpf.
Current release - regressions:
 
  - eth: stmmac: fix failure to probe without MAC interface specified
 
 Current release - new code bugs:
 
  - docs: netlink: fix missing classic_netlink doc reference
 
 Previous releases - regressions:
 
  - deal with integer overflows in kmalloc_reserve()
 
  - use sk_forward_alloc_get() in sk_get_meminfo()
 
  - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc
 
  - fib: avoid warn splat in flow dissector after packet mangling
 
  - skb_segment: call zero copy functions before using skbuff frags
 
  - eth: sfc: check for zero length in EF10 RX prefix
 
 Previous releases - always broken:
 
  - af_unix: fix msg_controllen test in scm_pidfd_recv() for
    MSG_CMSG_COMPAT
 
  - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR()
 
  - netfilter:
    - nft_exthdr: fix non-linear header modification
    - xt_u32, xt_sctp: validate user space input
    - nftables: exthdr: fix 4-byte stack OOB write
    - nfnetlink_osf: avoid OOB read
    - one more fix for the garbage collection work from last release
 
  - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU
 
  - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t
 
  - handshake: fix null-deref in handshake_nl_done_doit()
 
  - ip: ignore dst hint for multipath routes to ensure packets
    are hashed across the nexthops
 
  - phy: micrel:
    - correct bit assignments for cable test errata
    - disable EEE according to the KSZ9477 errata
 
 Misc:
 
  - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations
 
  - Revert "net: macsec: preserve ingress frame ordering", it appears
    to have been developed against an older kernel, problem doesn't
    exist upstream
 
 Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

Pull networking updates from Jakub Kicinski:
 "Including fixes from netfilter and bpf.

  Current release - regressions:

   - eth: stmmac: fix failure to probe without MAC interface specified

  Current release - new code bugs:

   - docs: netlink: fix missing classic_netlink doc reference

  Previous releases - regressions:

   - deal with integer overflows in kmalloc_reserve()

   - use sk_forward_alloc_get() in sk_get_meminfo()

   - bpf_sk_storage: fix the missing uncharge in sk_omem_alloc

   - fib: avoid warn splat in flow dissector after packet mangling

   - skb_segment: call zero copy functions before using skbuff frags

   - eth: sfc: check for zero length in EF10 RX prefix

  Previous releases - always broken:

   - af_unix: fix msg_controllen test in scm_pidfd_recv() for
     MSG_CMSG_COMPAT

   - xsk: fix xsk_build_skb() dereferencing possible ERR_PTR()

   - netfilter:
      - nft_exthdr: fix non-linear header modification
      - xt_u32, xt_sctp: validate user space input
      - nftables: exthdr: fix 4-byte stack OOB write
      - nfnetlink_osf: avoid OOB read
      - one more fix for the garbage collection work from last release

   - igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU

   - bpf, sockmap: fix preempt_rt splat when using raw_spin_lock_t

   - handshake: fix null-deref in handshake_nl_done_doit()

   - ip: ignore dst hint for multipath routes to ensure packets are
     hashed across the nexthops

   - phy: micrel:
      - correct bit assignments for cable test errata
      - disable EEE according to the KSZ9477 errata

  Misc:

   - docs/bpf: document compile-once-run-everywhere (CO-RE) relocations

   - Revert "net: macsec: preserve ingress frame ordering", it appears
     to have been developed against an older kernel, problem doesn't
     exist upstream"

* tag 'net-6.6-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (95 commits)
  net: enetc: distinguish error from valid pointers in enetc_fixup_clear_rss_rfs()
  Revert "net: team: do not use dynamic lockdep key"
  net: hns3: remove GSO partial feature bit
  net: hns3: fix the port information display when sfp is absent
  net: hns3: fix invalid mutex between tc qdisc and dcb ets command issue
  net: hns3: fix debugfs concurrency issue between kfree buffer and read
  net: hns3: fix byte order conversion issue in hclge_dbg_fd_tcam_read()
  net: hns3: Support query tx timeout threshold by debugfs
  net: hns3: fix tx timeout issue
  net: phy: Provide Module 4 KSZ9477 errata (DS80000754C)
  netfilter: nf_tables: Unbreak audit log reset
  netfilter: ipset: add the missing IP_SET_HASH_WITH_NET0 macro for ip_set_hash_netportnet.c
  netfilter: nft_set_rbtree: skip sync GC for new elements in this transaction
  netfilter: nf_tables: uapi: Describe NFTA_RULE_CHAIN_ID
  netfilter: nfnetlink_osf: avoid OOB read
  netfilter: nftables: exthdr: fix 4-byte stack OOB write
  selftests/bpf: Check bpf_sk_storage has uncharged sk_omem_alloc
  bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc
  bpf: bpf_sk_storage: Fix invalid wait context lockdep report
  s390/bpf: Pass through tail call counter in trampolines
  ...
2023-09-07 18:33:07 -07:00
Zheng Yejian
f6bd2c9248 ring-buffer: Avoid softlockup in ring_buffer_resize()
When user resize all trace ring buffer through file 'buffer_size_kb',
then in ring_buffer_resize(), kernel allocates buffer pages for each
cpu in a loop.

If the kernel preemption model is PREEMPT_NONE and there are many cpus
and there are many buffer pages to be allocated, it may not give up cpu
for a long time and finally cause a softlockup.

To avoid it, call cond_resched() after each cpu buffer allocation.

Link: https://lore.kernel.org/linux-trace-kernel/20230906081930.3939106-1-zhengyejian1@huawei.com

Cc: <mhiramat@kernel.org>
Signed-off-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:54 -04:00
Steven Rostedt (Google)
e5c624f027 tracing: Have event inject files inc the trace array ref count
The event inject files add events for a specific trace array. For an
instance, if the file is opened and the instance is deleted, reading or
writing to the file will cause a use after free.

Up the ref count of the trace_array when a event inject file is opened.

Link: https://lkml.kernel.org/r/20230907024804.292337868@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 6c3edaf9fd ("tracing: Introduce trace event injection")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:54 -04:00
Steven Rostedt (Google)
7e2cfbd2d3 tracing: Have option files inc the trace array ref count
The option files update the options for a given trace array. For an
instance, if the file is opened and the instance is deleted, reading or
writing to the file will cause a use after free.

Up the ref count of the trace_array when an option file is opened.

Link: https://lkml.kernel.org/r/20230907024804.086679464@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:54 -04:00
Steven Rostedt (Google)
9b37febc57 tracing: Have current_trace inc the trace array ref count
The current_trace updates the trace array tracer. For an instance, if the
file is opened and the instance is deleted, reading or writing to the file
will cause a use after free.

Up the ref count of the trace array when current_trace is opened.

Link: https://lkml.kernel.org/r/20230907024803.877687227@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:53 -04:00
Steven Rostedt (Google)
7d660c9b2b tracing: Have tracing_max_latency inc the trace array ref count
The tracing_max_latency file points to the trace_array max_latency field.
For an instance, if the file is opened and the instance is deleted,
reading or writing to the file will cause a use after free.

Up the ref count of the trace_array when tracing_max_latency is opened.

Link: https://lkml.kernel.org/r/20230907024803.666889383@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Zheng Yejian <zhengyejian1@huawei.com>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:38:53 -04:00
Steven Rostedt (Google)
f5ca233e2e tracing: Increase trace array ref count on enable and filter files
When the trace event enable and filter files are opened, increment the
trace array ref counter, otherwise they can be accessed when the trace
array is being deleted. The ref counter keeps the trace array from being
deleted while those files are opened.

Link: https://lkml.kernel.org/r/20230907024803.456187066@goodmis.org
Link: https://lore.kernel.org/all/1cb3aee2-19af-c472-e265-05176fe9bd84@huawei.com/

Cc: stable@vger.kernel.org
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Fixes: 8530dec63e ("tracing: Add tracing_check_open_get_tr()")
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Reported-by: Zheng Yejian <zhengyejian1@huawei.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2023-09-07 16:05:46 -04:00
Christoph Hellwig
4952801fc6 Revert "printk: export symbols for debug modules"
This reverts commit 3e00123a13.

No, we never export random symbols for out of tree modules.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
Link: https://lore.kernel.org/r/20230905081902.321778-1-hch@lst.de
2023-09-07 14:19:42 +02:00
Puranjay Mohan
20e490adea
bpf: make bpf_prog_pack allocator portable
The bpf_prog_pack allocator currently uses module_alloc() and
module_memfree() to allocate and free memory. This is not portable
because different architectures use different methods for allocating
memory for BPF programs. Like ARM64 and riscv use vmalloc()/vfree().

Use bpf_jit_alloc_exec() and bpf_jit_free_exec() for memory management
in bpf_prog_pack allocator. Other architectures can override these with
their implementation and will be able to use bpf_prog_pack directly.

On architectures that don't override bpf_jit_alloc/free_exec() this is
basically a NOP.

Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Acked-by: Song Liu <song@kernel.org>
Acked-by: Björn Töpel <bjorn@kernel.org>
Tested-by: Björn Töpel <bjorn@rivosinc.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/r/20230831131229.497941-2-puranjay12@gmail.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
2023-09-06 06:26:05 -07:00
Martin KaFai Lau
55d49f750b bpf: bpf_sk_storage: Fix the missing uncharge in sk_omem_alloc
The commit c83597fa5d ("bpf: Refactor some inode/task/sk storage functions
for reuse"), refactored the bpf_{sk,task,inode}_storage_free() into
bpf_local_storage_unlink_nolock() which then later renamed to
bpf_local_storage_destroy(). The commit accidentally passed the
"bool uncharge_mem = false" argument to bpf_selem_unlink_storage_nolock()
which then stopped the uncharge from happening to the sk->sk_omem_alloc.

This missing uncharge only happens when the sk is going away (during
__sk_destruct).

This patch fixes it by always passing "uncharge_mem = true". It is a
noop to the task/inode/cgroup storage because they do not have the
map_local_storage_(un)charge enabled in the map_ops. A followup patch
will be done in bpf-next to remove the uncharge_mem argument.

A selftest is added in the next patch.

Fixes: c83597fa5d ("bpf: Refactor some inode/task/sk storage functions for reuse")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230901231129.578493-3-martin.lau@linux.dev
2023-09-06 11:08:14 +02:00
Martin KaFai Lau
a96a44aba5 bpf: bpf_sk_storage: Fix invalid wait context lockdep report
'./test_progs -t test_local_storage' reported a splat:

[   27.137569] =============================
[   27.138122] [ BUG: Invalid wait context ]
[   27.138650] 6.5.0-03980-gd11ae1b16b0a #247 Tainted: G           O
[   27.139542] -----------------------------
[   27.140106] test_progs/1729 is trying to lock:
[   27.140713] ffff8883ef047b88 (stock_lock){-.-.}-{3:3}, at: local_lock_acquire+0x9/0x130
[   27.141834] other info that might help us debug this:
[   27.142437] context-{5:5}
[   27.142856] 2 locks held by test_progs/1729:
[   27.143352]  #0: ffffffff84bcd9c0 (rcu_read_lock){....}-{1:3}, at: rcu_lock_acquire+0x4/0x40
[   27.144492]  #1: ffff888107deb2c0 (&storage->lock){..-.}-{2:2}, at: bpf_local_storage_update+0x39e/0x8e0
[   27.145855] stack backtrace:
[   27.146274] CPU: 0 PID: 1729 Comm: test_progs Tainted: G           O       6.5.0-03980-gd11ae1b16b0a #247
[   27.147550] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014
[   27.149127] Call Trace:
[   27.149490]  <TASK>
[   27.149867]  dump_stack_lvl+0x130/0x1d0
[   27.152609]  dump_stack+0x14/0x20
[   27.153131]  __lock_acquire+0x1657/0x2220
[   27.153677]  lock_acquire+0x1b8/0x510
[   27.157908]  local_lock_acquire+0x29/0x130
[   27.159048]  obj_cgroup_charge+0xf4/0x3c0
[   27.160794]  slab_pre_alloc_hook+0x28e/0x2b0
[   27.161931]  __kmem_cache_alloc_node+0x51/0x210
[   27.163557]  __kmalloc+0xaa/0x210
[   27.164593]  bpf_map_kzalloc+0xbc/0x170
[   27.165147]  bpf_selem_alloc+0x130/0x510
[   27.166295]  bpf_local_storage_update+0x5aa/0x8e0
[   27.167042]  bpf_fd_sk_storage_update_elem+0xdb/0x1a0
[   27.169199]  bpf_map_update_value+0x415/0x4f0
[   27.169871]  map_update_elem+0x413/0x550
[   27.170330]  __sys_bpf+0x5e9/0x640
[   27.174065]  __x64_sys_bpf+0x80/0x90
[   27.174568]  do_syscall_64+0x48/0xa0
[   27.175201]  entry_SYSCALL_64_after_hwframe+0x6e/0xd8
[   27.175932] RIP: 0033:0x7effb40e41ad
[   27.176357] Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d8
[   27.179028] RSP: 002b:00007ffe64c21fc8 EFLAGS: 00000202 ORIG_RAX: 0000000000000141
[   27.180088] RAX: ffffffffffffffda RBX: 00007ffe64c22768 RCX: 00007effb40e41ad
[   27.181082] RDX: 0000000000000020 RSI: 00007ffe64c22008 RDI: 0000000000000002
[   27.182030] RBP: 00007ffe64c21ff0 R08: 0000000000000000 R09: 00007ffe64c22788
[   27.183038] R10: 0000000000000064 R11: 0000000000000202 R12: 0000000000000000
[   27.184006] R13: 00007ffe64c22788 R14: 00007effb42a1000 R15: 0000000000000000
[   27.184958]  </TASK>

It complains about acquiring a local_lock while holding a raw_spin_lock.
It means it should not allocate memory while holding a raw_spin_lock
since it is not safe for RT.

raw_spin_lock is needed because bpf_local_storage supports tracing
context. In particular for task local storage, it is easy to
get a "current" task PTR_TO_BTF_ID in tracing bpf prog.
However, task (and cgroup) local storage has already been moved to
bpf mem allocator which can be used after raw_spin_lock.

The splat is for the sk storage. For sk (and inode) storage,
it has not been moved to bpf mem allocator. Using raw_spin_lock or not,
kzalloc(GFP_ATOMIC) could theoretically be unsafe in tracing context.
However, the local storage helper requires a verifier accepted
sk pointer (PTR_TO_BTF_ID), it is hypothetical if that (mean running
a bpf prog in a kzalloc unsafe context and also able to hold a verifier
accepted sk pointer) could happen.

This patch avoids kzalloc after raw_spin_lock to silent the splat.
There is an existing kzalloc before the raw_spin_lock. At that point,
a kzalloc is very likely required because a lookup has just been done
before. Thus, this patch always does the kzalloc before acquiring
the raw_spin_lock and remove the later kzalloc usage after the
raw_spin_lock. After this change, it will have a charge and then
uncharge during the syscall bpf_map_update_elem() code path.
This patch opts for simplicity and not continue the old
optimization to save one charge and uncharge.

This issue is dated back to the very first commit of bpf_sk_storage
which had been refactored multiple times to create task, inode, and
cgroup storage. This patch uses a Fixes tag with a more recent
commit that should be easier to do backport.

Fixes: b00fa38a9c ("bpf: Enable non-atomic allocations in local storage")
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230901231129.578493-2-martin.lau@linux.dev
2023-09-06 11:07:54 +02:00
Sebastian Andrzej Siewior
6764e767f4 bpf: Assign bpf_tramp_run_ctx::saved_run_ctx before recursion check.
__bpf_prog_enter_recur() assigns bpf_tramp_run_ctx::saved_run_ctx before
performing the recursion check which means in case of a recursion
__bpf_prog_exit_recur() uses the previously set bpf_tramp_run_ctx::saved_run_ctx
value.

__bpf_prog_enter_sleepable_recur() assigns bpf_tramp_run_ctx::saved_run_ctx
after the recursion check which means in case of a recursion
__bpf_prog_exit_sleepable_recur() uses an uninitialized value. This does not
look right. If I read the entry trampoline code right, then bpf_tramp_run_ctx
isn't initialized upfront.

Align __bpf_prog_enter_sleepable_recur() with __bpf_prog_enter_recur() and
set bpf_tramp_run_ctx::saved_run_ctx before the recursion check is made.
Remove the assignment of saved_run_ctx in kern_sys_bpf() since it happens
a few cycles later.

Fixes: e384c7b7b4 ("bpf, x86: Create bpf_tramp_run_ctx on the caller thread's stack")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230830080405.251926-3-bigeasy@linutronix.de
2023-09-06 10:44:28 +02:00
Sebastian Andrzej Siewior
7645629f7d bpf: Invoke __bpf_prog_exit_sleepable_recur() on recursion in kern_sys_bpf().
If __bpf_prog_enter_sleepable_recur() detects recursion then it returns
0 without undoing rcu_read_lock_trace(), migrate_disable() or
decrementing the recursion counter. This is fine in the JIT case because
the JIT code will jump in the 0 case to the end and invoke the matching
exit trampoline (__bpf_prog_exit_sleepable_recur()).

This is not the case in kern_sys_bpf() which returns directly to the
caller with an error code.

Add __bpf_prog_exit_sleepable_recur() as clean up in the recursion case.

Fixes: b1d18a7574 ("bpf: Extend sys_bpf commands for bpf_syscall programs.")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230830080405.251926-2-bigeasy@linutronix.de
2023-09-06 10:39:31 +02:00
Linus Torvalds
61401a8724 Kbuild updates for v6.6
- Enable -Wenum-conversion warning option
 
  - Refactor the rpm-pkg target
 
  - Fix scripts/setlocalversion to consider annotated tags for rt-kernel
 
  - Add a jump key feature for the search menu of 'make nconfig'
 
  - Support Qt6 for 'make xconfig'
 
  - Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow, and
    -Wrestrict warnings for W=1 builds
 
  - Replace <asm/export.h> with <linux/export.h> for alpha, ia64, and sparc
 
  - Support DEB_BUILD_OPTIONS=parallel=N for the debian source package
 
  - Refactor scripts/Makefile.modinst and fix some modules_sign issues
 
  - Add a new Kconfig env variable to warn symbols that are not defined anywhere
 
  - Show help messages of config fragments in 'make help'
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Merge tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Enable -Wenum-conversion warning option

 - Refactor the rpm-pkg target

 - Fix scripts/setlocalversion to consider annotated tags for rt-kernel

 - Add a jump key feature for the search menu of 'make nconfig'

 - Support Qt6 for 'make xconfig'

 - Enable -Wformat-overflow, -Wformat-truncation, -Wstringop-overflow,
   and -Wrestrict warnings for W=1 builds

 - Replace <asm/export.h> with <linux/export.h> for alpha, ia64, and
   sparc

 - Support DEB_BUILD_OPTIONS=parallel=N for the debian source package

 - Refactor scripts/Makefile.modinst and fix some modules_sign issues

 - Add a new Kconfig env variable to warn symbols that are not defined
   anywhere

 - Show help messages of config fragments in 'make help'

* tag 'kbuild-v6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (62 commits)
  kconfig: fix possible buffer overflow
  kbuild: Show marked Kconfig fragments in "help"
  kconfig: add warn-unknown-symbols sanity check
  kbuild: dummy-tools: make MPROFILE_KERNEL checks work on BE
  Documentation/llvm: refresh docs
  modpost: Skip .llvm.call-graph-profile section check
  kbuild: support modules_sign for external modules as well
  kbuild: support 'make modules_sign' with CONFIG_MODULE_SIG_ALL=n
  kbuild: move more module installation code to scripts/Makefile.modinst
  kbuild: reduce the number of mkdir calls during modules_install
  kbuild: remove $(MODLIB)/source symlink
  kbuild: move depmod rule to scripts/Makefile.modinst
  kbuild: add modules_sign to no-{compiler,sync-config}-targets
  kbuild: do not run depmod for 'make modules_sign'
  kbuild: deb-pkg: support DEB_BUILD_OPTIONS=parallel=N in debian/rules
  alpha: remove <asm/export.h>
  alpha: replace #include <asm/export.h> with #include <linux/export.h>
  ia64: remove <asm/export.h>
  ia64: replace #include <asm/export.h> with #include <linux/export.h>
  sparc: remove <asm/export.h>
  ...
2023-09-05 11:01:47 -07:00
Linus Torvalds
3c31041e37 printk changes for 6.6
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Merge tag 'printk-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux

Pull printk updates from Petr Mladek:

 - Do not try to get the console lock when it is not need or useful in
   panic()

 - Replace the global console_suspended state by a per-console flag

 - Export symbols needed for dumping the raw printk buffer in panic()

 - Fix documentation of printf formats for integer types

 - Moved Sergey Senozhatsky to the reviewer role

 - Misc cleanups

* tag 'printk-for-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
  printk: export symbols for debug modules
  lib: test_scanf: Add explicit type cast to result initialization in test_number_prefix()
  printk: ringbuffer: Fix truncating buffer size min_t cast
  printk: Rename abandon_console_lock_in_panic() to other_cpu_in_panic()
  printk: Add per-console suspended state
  printk: Consolidate console deferred printing
  printk: Do not take console lock for console_flush_on_panic()
  printk: Keep non-panic-CPUs out of console lock
  printk: Reduce console_unblank() usage in unsafe scenarios
  kdb: Do not assume write() callback available
  docs: printk-formats: Treat char as always unsigned
  docs: printk-formats: Fix hex printing of signed values
  MAINTAINERS: adjust printk/vsprintf entries
2023-09-04 13:20:19 -07:00