21159 Commits

Author SHA1 Message Date
Naveen N Rao
5c70542f32 powerpc/ftrace: Fix stack teardown in ftrace_no_trace
commit 4b3338aaa74d7d4ec5b6734dc298f0db94ec83d2 upstream.

Commit 41a506ef71eb ("powerpc/ftrace: Create a dummy stackframe to fix
stack unwind") added use of a new stack frame on ftrace entry to fix
stack unwind. However, the commit missed updating the offset used while
tearing down the ftrace stack when ftrace is disabled. Fix the same.

In addition, the commit missed saving the correct stack pointer in
pt_regs. Update the same.

Fixes: 41a506ef71eb ("powerpc/ftrace: Create a dummy stackframe to fix stack unwind")
Cc: stable@vger.kernel.org # v6.5+
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231130065947.2188860-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20 15:41:26 +01:00
Naveen N Rao
0e1867b482 powerpc/ftrace: Create a dummy stackframe to fix stack unwind
commit 41a506ef71eb38d94fe133f565c87c3e06ccc072 upstream.

With ppc64 -mprofile-kernel and ppc32 -pg, profiling instructions to
call into ftrace are emitted right at function entry. The instruction
sequence used is minimal to reduce overhead. Crucially, a stackframe is
not created for the function being traced. This breaks stack unwinding
since the function being traced does not have a stackframe for itself.
As such, it never shows up in the backtrace:

/sys/kernel/debug/tracing # echo 1 > /proc/sys/kernel/stack_tracer_enabled
/sys/kernel/debug/tracing # cat stack_trace
        Depth    Size   Location    (17 entries)
        -----    ----   --------
  0)     4144      32   ftrace_call+0x4/0x44
  1)     4112     432   get_page_from_freelist+0x26c/0x1ad0
  2)     3680     496   __alloc_pages+0x290/0x1280
  3)     3184     336   __folio_alloc+0x34/0x90
  4)     2848     176   vma_alloc_folio+0xd8/0x540
  5)     2672     272   __handle_mm_fault+0x700/0x1cc0
  6)     2400     208   handle_mm_fault+0xf0/0x3f0
  7)     2192      80   ___do_page_fault+0x3e4/0xbe0
  8)     2112     160   do_page_fault+0x30/0xc0
  9)     1952     256   data_access_common_virt+0x210/0x220
 10)     1696     400   0xc00000000f16b100
 11)     1296     384   load_elf_binary+0x804/0x1b80
 12)      912     208   bprm_execve+0x2d8/0x7e0
 13)      704      64   do_execveat_common+0x1d0/0x2f0
 14)      640     160   sys_execve+0x54/0x70
 15)      480      64   system_call_exception+0x138/0x350
 16)      416     416   system_call_common+0x160/0x2c4

Fix this by having ftrace create a dummy stackframe for the function
being traced. With this, backtraces now capture the function being
traced:

/sys/kernel/debug/tracing # cat stack_trace
        Depth    Size   Location    (17 entries)
        -----    ----   --------
  0)     3888      32   _raw_spin_trylock+0x8/0x70
  1)     3856     576   get_page_from_freelist+0x26c/0x1ad0
  2)     3280      64   __alloc_pages+0x290/0x1280
  3)     3216     336   __folio_alloc+0x34/0x90
  4)     2880     176   vma_alloc_folio+0xd8/0x540
  5)     2704     416   __handle_mm_fault+0x700/0x1cc0
  6)     2288      96   handle_mm_fault+0xf0/0x3f0
  7)     2192      48   ___do_page_fault+0x3e4/0xbe0
  8)     2144     192   do_page_fault+0x30/0xc0
  9)     1952     608   data_access_common_virt+0x210/0x220
 10)     1344      16   0xc0000000334bbb50
 11)     1328     416   load_elf_binary+0x804/0x1b80
 12)      912      64   bprm_execve+0x2d8/0x7e0
 13)      848     176   do_execveat_common+0x1d0/0x2f0
 14)      672     192   sys_execve+0x54/0x70
 15)      480      64   system_call_exception+0x138/0x350
 16)      416     416   system_call_common+0x160/0x2c4

This results in two additional stores in the ftrace entry code, but
produces reliable backtraces.

Fixes: 153086644fd1 ("powerpc/ftrace: Add support for -mprofile-kernel ftrace ABI")
Cc: stable@vger.kernel.org
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230621051349.759567-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-20 15:41:26 +01:00
Timothy Pearson
30b807d736 powerpc: Don't clobber f0/vs0 during fp|altivec register save
commit 5e1d824f9a283cbf90f25241b66d1f69adb3835b upstream.

During floating point and vector save to thread data f0/vs0 are
clobbered by the FPSCR/VSCR store routine. This has been obvserved to
lead to userspace register corruption and application data corruption
with io-uring.

Fix it by restoring f0/vs0 after FPSCR/VSCR store has completed for
all the FP, altivec, VMX register save paths.

Tested under QEMU in kvm mode, running on a Talos II workstation with
dual POWER9 DD2.2 CPUs.

Additional detail (mpe):

Typically save_fpu() is called from __giveup_fpu() which saves the FP
regs and also *turns off FP* in the tasks MSR, meaning the kernel will
reload the FP regs from the thread struct before letting the task use FP
again. So in that case save_fpu() is free to clobber f0 because the FP
regs no longer hold live values for the task.

There is another case though, which is the path via:
  sys_clone()
    ...
    copy_process()
      dup_task_struct()
        arch_dup_task_struct()
          flush_all_to_thread()
            save_all()

That path saves the FP regs but leaves them live. That's meant as an
optimisation for a process that's using FP/VSX and then calls fork(),
leaving the regs live means the parent process doesn't have to take a
fault after the fork to get its FP regs back. The optimisation was added
in commit 8792468da5e1 ("powerpc: Add the ability to save FPU without
giving it up").

That path does clobber f0, but f0 is volatile across function calls,
and typically programs reach copy_process() from userspace via a syscall
wrapper function. So in normal usage f0 being clobbered across a
syscall doesn't cause visible data corruption.

But there is now a new path, because io-uring can call copy_process()
via create_io_thread() from the signal handling path. That's OK if the
signal is handled as part of syscall return, but it's not OK if the
signal is handled due to some other interrupt.

That path is:

interrupt_return_srr_user()
  interrupt_exit_user_prepare()
    interrupt_exit_user_prepare_main()
      do_notify_resume()
        get_signal()
          task_work_run()
            create_worker_cb()
              create_io_worker()
                copy_process()
                  dup_task_struct()
                    arch_dup_task_struct()
                      flush_all_to_thread()
                        save_all()
                          if (tsk->thread.regs->msr & MSR_FP)
                            save_fpu()
                            # f0 is clobbered and potentially live in userspace

Note the above discussion applies equally to save_altivec().

Fixes: 8792468da5e1 ("powerpc: Add the ability to save FPU without giving it up")
Cc: stable@vger.kernel.org # v4.6+
Closes: https://lore.kernel.org/all/480932026.45576726.1699374859845.JavaMail.zimbra@raptorengineeringinc.com/
Closes: https://lore.kernel.org/linuxppc-dev/480221078.47953493.1700206777956.JavaMail.zimbra@raptorengineeringinc.com/
Tested-by: Timothy Pearson <tpearson@raptorengineering.com>
Tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Timothy Pearson <tpearson@raptorengineering.com>
[mpe: Reword change log to describe exact path of corruption & other minor tweaks]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1921539696.48534988.1700407082933.JavaMail.zimbra@raptorengineeringinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-12-08 08:44:26 +01:00
Wang Yufen
247ed618f5 powerpc/pseries: fix potential memory leak in init_cpu_associativity()
[ Upstream commit 95f1a128cd728a7257d78e868f1f5a145fc43736 ]

If the vcpu_associativity alloc memory successfully but the
pcpu_associativity fails to alloc memory, the vcpu_associativity
memory leaks.

Fixes: d62c8deeb6e6 ("powerpc/pseries: Provide vcpu dispatch statistics")
Signed-off-by: Wang Yufen <wangyufen@huawei.com>
Reviewed-by: "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/1671003983-10794-1-git-send-email-wangyufen@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 10:30:14 +01:00
Sebastian Andrzej Siewior
cee681d4b2 powerpc/imc-pmu: Use the correct spinlock initializer.
[ Upstream commit 007240d59c11f87ac4f6cfc6a1d116630b6b634c ]

The macro __SPIN_LOCK_INITIALIZER() is implementation specific. Users
that desire to initialize a spinlock in a struct must use
__SPIN_LOCK_UNLOCKED().

Use __SPIN_LOCK_UNLOCKED() for the spinlock_t in imc_global_refc.

Fixes: 76d588dddc459 ("powerpc/imc-pmu: Fix use of mutex in IRQs disabled section")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230309134831.Nz12nqsU@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 10:30:14 +01:00
Benjamin Gray
dc5804b47b powerpc/xive: Fix endian conversion size
[ Upstream commit ff7a60ab1e065257a0e467c13b519f4debcd7fcf ]

Sparse reports a size mismatch in the endian swap. The Opal
implementation[1] passes the value as a __be64, and the receiving
variable out_qsize is a u64, so the use of be32_to_cpu() appears to be
an error.

[1]: https://github.com/open-power/skiboot/blob/80e2b1dc73/hw/xive.c#L3854

Fixes: 88ec6b93c8e7 ("powerpc/xive: add OPAL extensions for the XIVE native exploitation support")
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20231011053711.93427-2-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-11-20 10:30:14 +01:00
Christophe Leroy
de6e271338 powerpc/64e: Fix wrong test in __ptep_test_and_clear_young()
[ Upstream commit 5ea0bbaa32e8f54e9a57cfee4a3b8769b80be0d2 ]

Commit 45201c879469 ("powerpc/nohash: Remove hash related code from
nohash headers.") replaced:

  if ((pte_val(*ptep) & (_PAGE_ACCESSED | _PAGE_HASHPTE)) == 0)
	return 0;

By:

  if (pte_young(*ptep))
	return 0;

But it should be:

  if (!pte_young(*ptep))
	return 0;

Fix it.

Fixes: 45201c879469 ("powerpc/nohash: Remove hash related code from nohash headers.")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/8bb7f06494e21adada724ede47a4c3d97e879d40.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-25 11:53:20 +02:00
Christophe Leroy
85ae11da85 powerpc/8xx: Fix pte_access_permitted() for PAGE_NONE
[ Upstream commit 5d9cea8a552ee122e21fbd5a3c5d4eb85f648e06 ]

On 8xx, PAGE_NONE is handled by setting _PAGE_NA instead of clearing
_PAGE_USER.

But then pte_user() returns 1 also for PAGE_NONE.

As _PAGE_NA prevent reads, add a specific version of pte_read()
that returns 0 when _PAGE_NA is set instead of always returning 1.

Fixes: 351750331fc1 ("powerpc/mm: Introduce _PAGE_NA")
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/57bcfbe578e43123f9ed73e040229b80f1ad56ec.1695659959.git.christophe.leroy@csgroup.eu
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-25 11:53:20 +02:00
Benjamin Gray
b42eac1462 powerpc/watchpoints: Annotate atomic context in more places
[ Upstream commit 27646b2e02b096a6936b3e3b6ba334ae20763eab ]

It can be easy to miss that the notifier mechanism invokes the callbacks
in an atomic context, so add some comments to that effect on the two
handlers we register here.

Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230829063457.54157-4-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10 21:46:40 +02:00
Kajol Jain
16b88d7a14 powerpc/perf/hv-24x7: Update domain value check
[ Upstream commit 4ff3ba4db5943cac1045e3e4a3c0463ea10f6930 ]

Valid domain value is in range 1 to HV_PERF_DOMAIN_MAX. Current code has
check for domain value greater than or equal to HV_PERF_DOMAIN_MAX. But
the check for domain value 0 is missing.

Fix this issue by adding check for domain value 0.

Before:
  # ./perf stat -v -e hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ sleep 1
  Using CPUID 00800200
  Control descriptor is not initialized
  Error:
  The sys_perf_event_open() syscall returned with 5 (Input/output error) for
  event (hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/).
  /bin/dmesg | grep -i perf may provide additional information.

  Result from dmesg:
  [   37.819387] hv-24x7: hcall failed: [0 0x60040000 0x100 0] => ret
  0xfffffffffffffffc (-4) detail=0x2000000 failing ix=0

After:
  # ./perf stat -v -e hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ sleep 1
  Using CPUID 00800200
  Control descriptor is not initialized
  Warning:
  hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/ event is not supported by the kernel.
  failed to read counter hv_24x7/CPM_ADJUNCT_INST,domain=0,core=1/

Fixes: ebd4a5a3ebd9 ("powerpc/perf/hv-24x7: Minor improvements")
Reported-by: Krishan Gopal Sarawast <krishang@linux.vnet.ibm.com>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
Tested-by: Disha Goel <disgoel@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230825055601.360083-1-kjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-10-10 21:46:37 +02:00
ruanjinjie
7ffe14fce7 powerpc/pseries: fix possible memory leak in ibmebus_bus_init()
[ Upstream commit afda85b963c12947e298ad85d757e333aa40fd74 ]

If device_register() returns error in ibmebus_bus_init(), name of kobject
which is allocated in dev_set_name() called in device_add() is leaked.

As comment of device_add() says, it should call put_device() to drop
the reference count that was set in device_initialize() when it fails,
so the name can be freed in kobject_cleanup().

Signed-off-by: ruanjinjie <ruanjinjie@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20221110011929.3709774-1-ruanjinjie@huawei.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23 11:00:04 +02:00
Russell Currey
65bf8a196b powerpc/iommu: Fix notifiers being shared by PCI and VIO buses
[ Upstream commit c37b6908f7b2bd24dcaaf14a180e28c9132b9c58 ]

fail_iommu_setup() registers the fail_iommu_bus_notifier struct to both
PCI and VIO buses.  struct notifier_block is a linked list node, so this
causes any notifiers later registered to either bus type to also be
registered to the other since they share the same node.

This causes issues in (at least) the vgaarb code, which registers a
notifier for PCI buses.  pci_notify() ends up being called on a vio
device, converted with to_pci_dev() even though it's not a PCI device,
and finally makes a bad access in vga_arbiter_add_pci_device() as
discovered with KASAN:

 BUG: KASAN: slab-out-of-bounds in vga_arbiter_add_pci_device+0x60/0xe00
 Read of size 4 at addr c000000264c26fdc by task swapper/0/1

 Call Trace:
   dump_stack_lvl+0x1bc/0x2b8 (unreliable)
   print_report+0x3f4/0xc60
   kasan_report+0x244/0x698
   __asan_load4+0xe8/0x250
   vga_arbiter_add_pci_device+0x60/0xe00
   pci_notify+0x88/0x444
   notifier_call_chain+0x104/0x320
   blocking_notifier_call_chain+0xa0/0x140
   device_add+0xac8/0x1d30
   device_register+0x58/0x80
   vio_register_device_node+0x9ac/0xce0
   vio_bus_scan_register_devices+0xc4/0x13c
   __machine_initcall_pseries_vio_device_init+0x94/0xf0
   do_one_initcall+0x12c/0xaa8
   kernel_init_freeable+0xa48/0xba8
   kernel_init+0x64/0x400
   ret_from_kernel_thread+0x5c/0x64

Fix this by creating separate notifier_block structs for each bus type.

Fixes: d6b9a81b2a45 ("powerpc: IOMMU fault injection")
Reported-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Signed-off-by: Russell Currey <ruscur@russell.cc>
Tested-by: Nageswara R Sastry <rnsastry@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Add #ifdef to fix CONFIG_IBMVIO=n build]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230322035322.328709-1-ruscur@russell.cc
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23 10:59:48 +02:00
Sourabh Jain
81d1de3b97 powerpc/fadump: reset dump area size if fadump memory reserve fails
[ Upstream commit d1eb75e0dfed80d2d85b664e28a39f65b290ab55 ]

In case fadump_reserve_mem() fails to reserve memory, the
reserve_dump_area_size variable will retain the reserve area size. This
will lead to /sys/kernel/fadump/mem_reserved node displaying an incorrect
memory reserved by fadump.

To fix this problem, reserve dump area size variable is set to 0 if fadump
failed to reserve memory.

Fixes: 8255da95e545 ("powerpc/fadump: release all the memory above boot memory size")
Signed-off-by: Sourabh Jain <sourabhjain@linux.ibm.com>
Acked-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230704050715.203581-1-sourabhjain@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-09-23 10:59:47 +02:00
Christophe Leroy
3e2265cda1 powerpc/32s: Fix assembler warning about r0
commit b51ba4fe2e134b631f9c8f45423707aab71449b5 upstream.

The assembler says:
  arch/powerpc/kernel/head_32.S:1095: Warning: invalid register expression

It's objecting to the use of r0 as the RA argument. That's because
when RA = 0 the literal value 0 is used, rather than the content of
r0, making the use of r0 in the source potentially confusing.

Fix it to use a literal 0, the generated code is identical.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/2b69ac8e1cddff6f808fc7415907179eab4aae9e.1596693679.git.christophe.leroy@csgroup.eu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-23 10:59:40 +02:00
YueHaibing
94aef0fe5a powerpc/pmac/smp: Drop unnecessary volatile qualifier
commit a4037d1f1fc4e92b69d7196d4568c33078d465ea upstream.

core99_l2_cache/core99_l3_cache do not need to be marked as volatile,
remove it.

Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200303085604.24952-1-yuehaibing@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-02 09:19:18 +02:00
Ilie Halip
b29a10fd07 powerpc/pmac/smp: Avoid unused-variable warnings
commit 9451c79bc39e610882bdd12370f01af5004a3c4f upstream.

When building with ppc64_defconfig, the compiler reports
that these 2 variables are not used:
    warning: unused variable 'core99_l2_cache' [-Wunused-variable]
    warning: unused variable 'core99_l3_cache' [-Wunused-variable]

They are only used when CONFIG_PPC64 is not defined. Move
them into a section which does the same macro check.

Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Ilie Halip <ilie.halip@gmail.com>
[mpe: Move them into core99_init_caches() which is their only user]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190920153951.25762-1-ilie.halip@gmail.com
Cc: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-09-02 09:19:18 +02:00
Nathan Lynch
1d29e21ed0 powerpc/rtas_flash: allow user copy to flash block cache objects
commit 4f3175979e62de3b929bfa54a0db4b87d36257a7 upstream.

With hardened usercopy enabled (CONFIG_HARDENED_USERCOPY=y), using the
/proc/powerpc/rtas/firmware_update interface to prepare a system
firmware update yields a BUG():

  kernel BUG at mm/usercopy.c:102!
  Oops: Exception in kernel mode, sig: 5 [#1]
  LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries
  Modules linked in:
  CPU: 0 PID: 2232 Comm: dd Not tainted 6.5.0-rc3+ #2
  Hardware name: IBM,8408-E8E POWER8E (raw) 0x4b0201 0xf000004 of:IBM,FW860.50 (SV860_146) hv:phyp pSeries
  NIP:  c0000000005991d0 LR: c0000000005991cc CTR: 0000000000000000
  REGS: c0000000148c76a0 TRAP: 0700   Not tainted  (6.5.0-rc3+)
  MSR:  8000000000029033 <SF,EE,ME,IR,DR,RI,LE>  CR: 24002242  XER: 0000000c
  CFAR: c0000000001fbd34 IRQMASK: 0
  [ ... GPRs omitted ... ]
  NIP usercopy_abort+0xa0/0xb0
  LR  usercopy_abort+0x9c/0xb0
  Call Trace:
    usercopy_abort+0x9c/0xb0 (unreliable)
    __check_heap_object+0x1b4/0x1d0
    __check_object_size+0x2d0/0x380
    rtas_flash_write+0xe4/0x250
    proc_reg_write+0xfc/0x160
    vfs_write+0xfc/0x4e0
    ksys_write+0x90/0x160
    system_call_exception+0x178/0x320
    system_call_common+0x160/0x2c4

The blocks of the firmware image are copied directly from user memory
to objects allocated from flash_block_cache, so flash_block_cache must
be created using kmem_cache_create_usercopy() to mark it safe for user
access.

Fixes: 6d07d1cd300f ("usercopy: Restrict non-usercopy caches to size 0")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
[mpe: Trim and indent oops]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230810-rtas-flash-vs-hardened-usercopy-v2-1-dcf63793a938@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-30 16:27:15 +02:00
Benjamin Gray
635278e97a powerpc/kasan: Disable KCOV in KASAN code
[ Upstream commit ccb381e1af1ace292153c88eb1fffa5683d16a20 ]

As per the generic KASAN code in mm/kasan, disable KCOV with
KCOV_INSTRUMENT := n in the makefile.

This fixes a ppc64 boot hang when KCOV and KASAN are enabled.
kasan_early_init() gets called before a PACA is initialised, but the
KCOV hook expects a valid PACA.

Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230710044143.146840-1-bgray@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-30 16:27:11 +02:00
Aneesh Kumar K.V
a65e7b4b31 powerpc/mm/altmap: Fix altmap boundary check
[ Upstream commit 6722b25712054c0f903b839b8f5088438dd04df3 ]

altmap->free includes the entire free space from which altmap blocks
can be allocated. So when checking whether the kernel is doing altmap
block free, compute the boundary correctly, otherwise memory hotunplug
can fail.

Fixes: 9ef34630a461 ("powerpc/mm: Fallback to RAM if the altmap is unusable")
Signed-off-by: "Aneesh Kumar K.V" <aneesh.kumar@linux.ibm.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230724181320.471386-1-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-11 11:54:00 +02:00
ndesaulniers@google.com
d2fb096926 word-at-a-time: use the same return type for has_zero regardless of endianness
[ Upstream commit 79e8328e5acbe691bbde029a52c89d70dcbc22f3 ]

Compiling big-endian targets with Clang produces the diagnostic:

  fs/namei.c:2173:13: warning: use of bitwise '|' with boolean operands [-Wbitwise-instead-of-logical]
	} while (!(has_zero(a, &adata, &constants) | has_zero(b, &bdata, &constants)));
	          ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
                                               ||
  fs/namei.c:2173:13: note: cast one or both operands to int to silence this warning

It appears that when has_zero was introduced, two definitions were
produced with different signatures (in particular different return
types).

Looking at the usage in hash_name() in fs/namei.c, I suspect that
has_zero() is meant to be invoked twice per while loop iteration; using
logical-or would not update `bdata` when `a` did not have zeros.  So I
think it's preferred to always return an unsigned long rather than a
bool than update the while loop in hash_name() to use a logical-or
rather than bitwise-or.

[ Also changed powerpc version to do the same  - Linus ]

Link: https://github.com/ClangBuiltLinux/linux/issues/1832
Link: https://lore.kernel.org/lkml/20230801-bitwise-v1-1-799bec468dc4@google.com/
Fixes: 36126f8f2ed8 ("word-at-a-time: make the interfaces truly generic")
Debugged-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Heiko Carstens <hca@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-08-11 11:53:54 +02:00
Thomas Gleixner
944d5c3ffa init: Remove check_bugs() leftovers
commit 61235b24b9cb37c13fcad5b9596d59a1afdcec30 upstream

Everything is converted over to arch_cpu_finalize_init(). Remove the
check_bugs() leftovers including the empty stubs in asm-generic, alpha,
parisc, powerpc and xtensa.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Link: https://lore.kernel.org/r/20230613224545.553215951@linutronix.de
Signed-off-by: Daniel Sneddon <daniel.sneddon@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-08-08 19:56:34 +02:00
Naveen N Rao
b157987242 powerpc: Fail build if using recordmcount with binutils v2.37
commit 25ea739ea1d4d3de41acc4f4eb2d1a97eee0eb75 upstream.

binutils v2.37 drops unused section symbols, which prevents recordmcount
from capturing mcount locations in sections that have no non-weak
symbols. This results in a build failure with a message such as:
	Cannot find symbol for section 12: .text.perf_callchain_kernel.
	kernel/events/callchain.o: failed

The change to binutils was reverted for v2.38, so this behavior is
specific to binutils v2.37:
https://sourceware.org/git/?p=binutils-gdb.git;a=commit;h=c09c8b42021180eee9495bd50d8b35e683d3901b

Objtool is able to cope with such sections, so this issue is specific to
recordmcount.

Fail the build and print a warning if binutils v2.37 is detected and if
we are using recordmcount.

Cc: stable@vger.kernel.org
Suggested-by: Joel Stanley <joel@jms.id.au>
Signed-off-by: Naveen N Rao <naveen@kernel.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230530061436.56925-1-naveen@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-07-27 08:37:34 +02:00
Randy Dunlap
fffa51e786 powerpc: allow PPC_EARLY_DEBUG_CPM only when SERIAL_CPM=y
[ Upstream commit 39f49684036d24af800ff194c33c7b2653c591d7 ]

In a randconfig with CONFIG_SERIAL_CPM=m and
CONFIG_PPC_EARLY_DEBUG_CPM=y, there is a build error:
ERROR: modpost: "udbg_putc" [drivers/tty/serial/cpm_uart/cpm_uart.ko] undefined!

Prevent the build error by allowing PPC_EARLY_DEBUG_CPM only when
SERIAL_CPM=y.

Fixes: c374e00e17f1 ("[POWERPC] Add early debug console for CPM serial ports.")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Pali Rohár <pali@kernel.org>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230701054714.30512-1-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:37:23 +02:00
Aneesh Kumar K.V
2cbfb51d2c powerpc/mm/dax: Fix the condition when checking if altmap vmemap can cross-boundary
[ Upstream commit c8eebc4a99f15280654f23e914e746c40a516e50 ]

Without this fix, the last subsection vmemmap can end up in memory even if
the namespace is created with -M mem and has sufficient space in the altmap
area.

Fixes: cf387d9644d8 ("libnvdimm/altmap: Track namespace boundaries in altmap")
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Tested-by: Sachin Sant <sachinp@linux.ibm.com <mailto:sachinp@linux.ibm.com>>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230616110826.344417-6-aneesh.kumar@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-07-27 08:37:17 +02:00
Stephen Hemminger
6b1203ae83 Remove DECnet support from kernel
commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream.

DECnet is an obsolete network protocol that receives more attention
from kernel janitors than users. It belongs in computer protocol
history museum not in Linux kernel.

It has been "Orphaned" in kernel since 2010. The iproute2 support
for DECnet was dropped in 5.0 release. The documentation link on
Sourceforge says it is abandoned there as well.

Leave the UAPI alone to keep userspace programs compiling.
This means that there is still an empty neighbour table
for AF_DECNET.

The table of /proc/sys/net entries was updated to match
current directories and reformatted to be alphabetical.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Ahern <dsahern@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21 15:44:10 +02:00
Ricardo Ribalda
01fd784b07 powerpc/purgatory: remove PGO flags
commit 20188baceb7a1463dc0bcb0c8678b69c2f447df6 upstream.

If profile-guided optimization is enabled, the purgatory ends up with
multiple .text sections.  This is not supported by kexec and crashes the
system.

Link: https://lkml.kernel.org/r/20230321-kexec_clang16-v7-3-b05c520b7296@chromium.org
Fixes: 930457057abe ("kernel/kexec_file.c: split up __kexec_load_puragory")
Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: <stable@vger.kernel.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Baoquan He <bhe@redhat.com>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Philipp Rudo <prudo@redhat.com>
Cc: Ross Zwisler <zwisler@google.com>
Cc: Simon Horman <horms@kernel.org>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tom Rix <trix@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-21 15:44:10 +02:00
Kees Cook
0638dcc7e7 treewide: Remove uninitialized_var() usage
commit 3f649ab728cda8038259d8f14492fe400fbab911 upstream.

Using uninitialized_var() is dangerous as it papers over real bugs[1]
(or can in the future), and suppresses unrelated compiler warnings
(e.g. "unused variable"). If the compiler thinks it is uninitialized,
either simply initialize the variable or make compiler changes.

In preparation for removing[2] the[3] macro[4], remove all remaining
needless uses with the following script:

git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \
	xargs perl -pi -e \
		's/\buninitialized_var\(([^\)]+)\)/\1/g;
		 s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;'

drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid
pathological white-space.

No outstanding warnings were found building allmodconfig with GCC 9.3.0
for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64,
alpha, and m68k.

[1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/
[2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/
[3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/
[4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/

Reviewed-by: Leon Romanovsky <leonro@mellanox.com> # drivers/infiniband and mlx4/mlx5
Acked-by: Jason Gunthorpe <jgg@mellanox.com> # IB
Acked-by: Kalle Valo <kvalo@codeaurora.org> # wireless drivers
Reviewed-by: Chao Yu <yuchao0@huawei.com> # erofs
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-06-09 10:29:01 +02:00
Michael Ellerman
df89b1753e powerpc/64s/radix: Fix soft dirty tracking
commit 66b2ca086210732954a7790d63d35542936fc664 upstream.

It was reported that soft dirty tracking doesn't work when using the
Radix MMU.

The tracking is supposed to work by clearing the soft dirty bit for a
mapping and then write protecting the PTE. If/when the page is written
to, a page fault occurs and the soft dirty bit is added back via
pte_mkdirty(). For example in wp_page_reuse():

	entry = maybe_mkwrite(pte_mkdirty(entry), vma);
	if (ptep_set_access_flags(vma, vmf->address, vmf->pte, entry, 1))
		update_mmu_cache(vma, vmf->address, vmf->pte);

Unfortunately on radix _PAGE_SOFTDIRTY is being dropped by
radix__ptep_set_access_flags(), called from ptep_set_access_flags(),
meaning the soft dirty bit is not set even though the page has been
written to.

Fix it by adding _PAGE_SOFTDIRTY to the set of bits that are able to be
changed in radix__ptep_set_access_flags().

Fixes: b0b5e9b13047 ("powerpc/mm/radix: Add radix pte #defines")
Cc: stable@vger.kernel.org # v4.7+
Reported-by: Dan Horák <dan@danny.cz>
Link: https://lore.kernel.org/r/20230511095558.56663a50f86bdc4cd97700b7@danny.cz
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230511114224.977423-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-05-30 12:44:07 +01:00
Nathan Lynch
ff3edfb3c8 powerpc/rtas: use memmove for potentially overlapping buffer copy
[ Upstream commit 271208ee5e335cb1ad280d22784940daf7ddf820 ]

Using memcpy() isn't safe when buf is identical to rtas_err_buf, which
can happen during boot before slab is up. Full context which may not
be obvious from the diff:

	if (altbuf) {
		buf = altbuf;
	} else {
		buf = rtas_err_buf;
		if (slab_is_available())
			buf = kmalloc(RTAS_ERROR_LOG_MAX, GFP_ATOMIC);
	}
	if (buf)
		memcpy(buf, rtas_err_buf, RTAS_ERROR_LOG_MAX);

This was found by inspection and I'm not aware of it causing problems
in practice. It appears to have been introduced by commit
033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel"); the
old ppc64 version of this code did not have this problem.

Use memmove() instead.

Fixes: 033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel")
Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230220-rtas-queue-for-6-4-v1-2-010e4416f13f@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17 11:35:50 +02:00
Randy Dunlap
e2dd8bbab7 powerpc/sysdev/tsi108: fix resource printk format warnings
[ Upstream commit 55d8bd02cc1b9f1063993b5c42c9cabf4af67dea ]

Use "%pa" format specifier for resource_size_t to avoid a compiler
printk format warning.

  arch/powerpc/sysdev/tsi108_pci.c: In function 'tsi108_setup_pci':
  include/linux/kern_levels.h:5:25: error: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'resource_size_t'

Fixes: c4342ff92bed ("[POWERPC] Update mpc7448hpc2 board irq support using device tree")
Fixes: 2b9d7467a6db ("[POWERPC] Add tsi108 pci and platform device data register function")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
[mpe: Use pr_info() and unsplit string]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230223070116.660-5-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17 11:35:50 +02:00
Randy Dunlap
770d583cd5 powerpc/wii: fix resource printk format warnings
[ Upstream commit 7b69600d4da0049244e9be2f5ef5a2f8e04fcd9a ]

Use "%pa" format specifier for resource_size_t to avoid compiler
printk format warnings.

../arch/powerpc/platforms/embedded6xx/flipper-pic.c: In function 'flipper_pic_init':
../include/linux/kern_levels.h:5:25: error: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
../arch/powerpc/platforms/embedded6xx/flipper-pic.c:148:9: note: in expansion of macro 'pr_info'
  148 |         pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
      |         ^~~~~~~

../arch/powerpc/platforms/embedded6xx/hlwd-pic.c: In function 'hlwd_pic_init':
../include/linux/kern_levels.h:5:25: error: format '%x' expects argument of type 'unsigned int', but argument 2 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
../arch/powerpc/platforms/embedded6xx/hlwd-pic.c:174:9: note: in expansion of macro 'pr_info'
  174 |         pr_info("controller at 0x%08x mapped to 0x%p\n", res.start, io_base);
      |         ^~~~~~~

../arch/powerpc/platforms/embedded6xx/wii.c: In function 'wii_ioremap_hw_regs':
../include/linux/kern_levels.h:5:25: error: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
../arch/powerpc/platforms/embedded6xx/wii.c:77:17: note: in expansion of macro 'pr_info'
   77 |                 pr_info("%s at 0x%08x mapped to 0x%p\n", name,
      |                 ^~~~~~~

Fixes: 028ee972f032 ("powerpc: gamecube/wii: flipper interrupt controller support")
Fixes: 9c21025c7845 ("powerpc: wii: hollywood interrupt controller support")
Fixes: 5a7ee3198dfa ("powerpc: wii: platform support")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230223070116.660-3-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17 11:35:50 +02:00
Randy Dunlap
f60c8d7c16 powerpc/mpc512x: fix resource printk format warning
[ Upstream commit 7538c97e2b80ff6b7a8ea2ecf16a04355461b439 ]

Use "%pa" format specifier for resource_size_t to avoid a compiler
printk format warning.

../arch/powerpc/platforms/512x/clock-commonclk.c: In function 'mpc5121_clk_provide_backwards_compat':
../arch/powerpc/platforms/512x/clock-commonclk.c:989:44: error: format '%x' expects argument of type 'unsigned int', but argument 4 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
  989 |         snprintf(devname, sizeof(devname), "%08x.%s", res.start, np->name); \
      |                                            ^~~~~~~~~  ~~~~~~~~~
      |                                                          |
      |                                                          resource_size_t {aka long long unsigned int}

Prevents 24 such warnings.

Fixes: 01f25c371658 ("clk: mpc512x: add backwards compat to the CCF code")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230223070116.660-2-rdunlap@infradead.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-05-17 11:35:50 +02:00
Christoph Hellwig
9690e34f22 dma-mapping: drop the dev argument to arch_sync_dma_for_*
[ Upstream commit 56e35f9c5b87ec1ae93e483284e189c84388de16 ]

These are pure cache maintainance routines, so drop the unused
struct device argument.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Stable-dep-of: ab327f8acdf8 ("mips: bmips: BCM6358: disable RAC flush for TP1")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-04-05 11:16:43 +02:00
Michael Ellerman
219cc98501 powerpc/vmlinux.lds: Don't discard .rela* for relocatable builds
commit 07b050f9290ee012a407a0f64151db902a1520f5 upstream.

Relocatable kernels must not discard relocations, they need to be
processed at runtime. As such they are included for CONFIG_RELOCATABLE
builds in the powerpc linker script (line 340).

However they are also unconditionally discarded later in the
script (line 414). Previously that worked because the earlier inclusion
superseded the discard.

However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 137). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier, causing .rela* to
actually be discarded at link time, leading to build warnings and a
kernel that doesn't boot:

  ld: warning: discarding dynamic section .rela.init.rodata

Fix it by conditionally discarding .rela* only when CONFIG_RELOCATABLE
is disabled.

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

Link: https://lore.kernel.org/r/20230105132349.384666-2-mpe@ellerman.id.au
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:32:53 +01:00
Michael Ellerman
4eede1173f powerpc/vmlinux.lds: Define RUNTIME_DISCARD_EXIT
commit 4b9880dbf3bdba3a7c56445137c3d0e30aaa0a40 upstream.

The powerpc linker script explicitly includes .exit.text, because
otherwise the link fails due to references from __bug_table and
__ex_table. The code is freed (discarded) at runtime along with
.init.text and data.

That has worked in the past despite powerpc not defining
RUNTIME_DISCARD_EXIT because DISCARDS appears late in the powerpc linker
script (line 410), and the explicit inclusion of .exit.text
earlier (line 280) supersedes the discard.

However commit 99cb0d917ffa ("arch: fix broken BuildID for arm64 and
riscv") introduced an earlier use of DISCARD as part of the RO_DATA
macro (line 136). With binutils < 2.36 that causes the DISCARD
directives later in the script to be applied earlier [1], causing
.exit.text to actually be discarded at link time, leading to build
errors:

  '.exit.text' referenced in section '__bug_table' of crypto/algboss.o: defined in
  discarded section '.exit.text' of crypto/algboss.o
  '.exit.text' referenced in section '__ex_table' of drivers/nvdimm/core.o: defined in
  discarded section '.exit.text' of drivers/nvdimm/core.o

Fix it by defining RUNTIME_DISCARD_EXIT, which causes the generic
DISCARDS macro to not include .exit.text at all.

1: https://lore.kernel.org/lkml/87fscp2v7k.fsf@igel.home/

Fixes: 99cb0d917ffa ("arch: fix broken BuildID for arm64 and riscv")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230105132349.384666-1-mpe@ellerman.id.au
Signed-off-by: Tom Saeger <tom.saeger@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-03-17 08:32:53 +01:00
Nathan Chancellor
ec6bd0dccd powerpc: Remove linker flag from KBUILD_AFLAGS
[ Upstream commit 31f48f16264bc70962fb3e7ec62da64d0a2ba04a ]

When clang's -Qunused-arguments is dropped from KBUILD_CPPFLAGS, it
points out that KBUILD_AFLAGS contains a linker flag, which will be
unused:

  clang: error: -Wl,-a32: 'linker' input unused [-Werror,-Wunused-command-line-argument]

This was likely supposed to be '-Wa,-a$(BITS)'. However, this change is
unnecessary, as all supported versions of clang and gcc will pass '-a64'
or '-a32' to GNU as based on the value of '-m'; the behavior of the
latest stable release of the oldest supported major version of each
compiler is shown below and each compiler's latest release exhibits the
same behavior (GCC 12.2.0 and Clang 15.0.6).

  $ powerpc64-linux-gcc --version | head -1
  powerpc64-linux-gcc (GCC) 5.5.0

  $ powerpc64-linux-gcc -m64 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as '
  .../as -a64 -mppc64 -many -mbig -o /dev/null /tmp/cctwuBzZ.s

  $ powerpc64-linux-gcc -m32 -### -x assembler-with-cpp -c -o /dev/null /dev/null &| grep 'as '
  .../as -a32 -mppc -many -mbig -o /dev/null /tmp/ccaZP4mF.sg

  $ clang --version | head -1
  Ubuntu clang version 11.1.0-++20211011094159+1fdec59bffc1-1~exp1~20211011214622.5

  $ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \
    -x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as
   "/usr/bin/powerpc64-linux-gnu-as" "-a64" "-mppc64" "-many" "-o" "/dev/null" "/tmp/null-80267c.s"

  $ clang --target=powerpc64-linux-gnu -fno-integrated-as -m64 -### \
    -x assembler-with-cpp -c -o /dev/null /dev/null &| grep gnu-as
   "/usr/bin/powerpc64-linux-gnu-as" "-a32" "-mppc" "-many" "-o" "/dev/null" "/tmp/null-ab8f8d.s"

Remove this flag altogether to avoid future issues.

Fixes: 1421dc6d4829 ("powerpc/kbuild: Use flags variables rather than overriding LD/CC/AS")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Tested-by: Linux Kernel Functional Testing <lkft@linaro.org>
Tested-by: Anders Roxell <anders.roxell@linaro.org>
Acked-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:53 +01:00
Ganesh Goudar
1abc7be57c powerpc/eeh: Set channel state after notifying the drivers
[ Upstream commit 9efcdaac36e1643a1b7f5337e6143ce142d381b1 ]

When a PCI error is encountered 6th time in an hour we
set the channel state to perm_failure and notify the
driver about the permanent failure.

However, after upstream commit 38ddc011478e ("powerpc/eeh:
Make permanently failed devices non-actionable"), EEH handler
stops calling any routine once the device is marked as
permanent failure. This issue can lead to fatal consequences
like kernel hang with certain PCI devices.

Following log is observed with lpfc driver, with and without
this change, Without this change kernel hangs, If PCI error
is encountered 6 times for a device in an hour.

Without the change

 EEH: Beginning: 'error_detected(permanent failure)'
 PCI 0132:60:00.0#600000: EEH: not actionable (1,1,1)
 PCI 0132:60:00.1#600000: EEH: not actionable (1,1,1)
 EEH: Finished:'error_detected(permanent failure)'

With the change

 EEH: Beginning: 'error_detected(permanent failure)'
 EEH: Invoking lpfc->error_detected(permanent failure)
 EEH: lpfc driver reports: 'disconnect'
 EEH: Invoking lpfc->error_detected(permanent failure)
 EEH: lpfc driver reports: 'disconnect'
 EEH: Finished:'error_detected(permanent failure)'

To fix the issue, set channel state to permanent failure after
notifying the drivers.

Fixes: 38ddc011478e ("powerpc/eeh: Make permanently failed devices non-actionable")
Suggested-by: Mahesh Salgaonkar <mahesh@linux.ibm.com>
Signed-off-by: Ganesh Goudar <ganeshgr@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230209105649.127707-1-ganeshgr@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:52 +01:00
Daniel Axtens
7719aba7a3 powerpc/eeh: Small refactor of eeh_handle_normal_event()
[ Upstream commit 10b34ece132ee46dc4e6459c765d180c422a09fa ]

The control flow of eeh_handle_normal_event() is a bit tricky.

Break out one of the error handling paths - rather than be in an else
block, we'll make it part of the regular body of the function and put a
'goto out;' in the true limb of the if.

Signed-off-by: Daniel Axtens <dja@axtens.net>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211015070628.1331635-1-dja@axtens.net
Stable-dep-of: 9efcdaac36e1 ("powerpc/eeh: Set channel state after notifying the drivers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:52 +01:00
Nathan Lynch
a39becb905 powerpc/rtas: ensure 4KB alignment for rtas_data_buf
[ Upstream commit 836b5b9fcc8e09cea7e8a59a070349a00e818308 ]

Some RTAS functions that have work area parameters impose alignment
requirements on the work area passed to them by the OS. Examples
include:

- ibm,configure-connector
- ibm,update-nodes
- ibm,update-properties

4KB is the greatest alignment required by PAPR for such
buffers. rtas_data_buf used to have a __page_aligned attribute in the
arch/ppc64 days, but that was changed to __cacheline_aligned for
unknown reasons by commit 033ef338b6e0 ("powerpc: Merge rtas.c into
arch/powerpc/kernel"). That works out to 128-byte alignment
on ppc64, which isn't right.

This was found by inspection and I'm not aware of any real problems
caused by this. Either current RTAS implementations don't enforce the
alignment constraints, or rtas_data_buf is always being placed at a
4KB boundary by accident (or both, perhaps).

Use __aligned(SZ_4K) to ensure the rtas_data_buf has alignment
appropriate for all users.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 033ef338b6e0 ("powerpc: Merge rtas.c into arch/powerpc/kernel")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-6-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:52 +01:00
Nathan Lynch
0616586eef powerpc/rtas: make all exports GPL
[ Upstream commit 9bce6243848dfd0ff7c2be6e8d82ab9b1e6c7858 ]

The first symbol exports of RTAS functions and data came with the (now
removed) scanlog driver in 2003:

https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/?id=f92e361842d5251e50562b09664082dcbd0548bb

At the time this was applied, EXPORT_SYMBOL_GPL() was very new, and
the exports of rtas_call() etc have remained non-GPL. As new APIs have
been added to the RTAS subsystem, their symbol exports have followed
the convention set by existing code.

However, the historical evidence is that RTAS function exports have been
added over time only to satisfy the needs of in-kernel users, and these
clients must have fairly intimate knowledge of how the APIs work to use
them safely. No out of tree users are known, and future ones seem
unlikely.

Arguably the default for RTAS symbols should have become
EXPORT_SYMBOL_GPL once it was available. Let's make it so now, and
exceptions can be evaluated as needed.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Laurent Dufour <laurent.dufour@fr.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230124140448.45938-3-nathanl@linux.ibm.com
Stable-dep-of: 836b5b9fcc8e ("powerpc/rtas: ensure 4KB alignment for rtas_data_buf")
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:52 +01:00
Nathan Lynch
d8ca498591 powerpc/pseries/lparcfg: add missing RTAS retry status handling
[ Upstream commit 5d08633e5f6564b60f1cbe09af3af40a74d66431 ]

The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again.

lparcfg's parse_system_parameter_string() ignores this, making it
possible to intermittently report incorrect SPLPAR characteristics.

Move the RTAS call into a coventional rtas_busy_delay()-based loop.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-4-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:51 +01:00
Nathan Lynch
421c59c23a powerpc/pseries/lpar: add missing RTAS retry status handling
[ Upstream commit daa8ab59044610aa8ef2ee45a6c157b5e11635e9 ]

The ibm,get-system-parameter RTAS function may return -2 or 990x,
which indicate that the caller should try again.

pseries_lpar_read_hblkrm_characteristics() ignores this, making it
possible to incorrectly detect TLB block invalidation characteristics
at boot.

Move the RTAS call into a coventional rtas_busy_delay()-based loop.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Fixes: 1211ee61b4a8 ("powerpc/pseries: Read TLB Block Invalidate Characteristics")
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230125-b4-powerpc-rtas-queue-v3-3-26929c8cce78@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:51 +01:00
Frederic Barrat
4d178dc25f powerpc/powernv/ioda: Skip unallocated resources when mapping to PE
[ Upstream commit e64e71056f323a1e178dccf04d4c0f032d84436c ]

pnv_ioda_setup_pe_res() calls opal to map a resource with a PE. However,
the code assumes the resource is allocated and it uses the resource
address to find out the segment(s) which need to be mapped to the
PE. In the unlikely case where the resource hasn't been allocated, the
computation for the segment number is garbage, which can lead to
invalid memory access and potentially a kernel crash, such as:

[ ] pci_bus 0002:02: Configuring PE for bus
[ ] pci 0002:02     : [PE# fc] Secondary bus 0x0000000000000002..0x0000000000000002 associated with PE#fc
[ ] BUG: Kernel NULL pointer dereference on write at 0x00000000
[ ] Faulting instruction address: 0xc00000000005eac4
[ ] Oops: Kernel access of bad area, sig: 7 [#1]
[ ] LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA PowerNV
[ ] Modules linked in:
[ ] CPU: 12 PID: 1 Comm: swapper/20 Not tainted 5.10.50-openpower1 #2
[ ] NIP:  c00000000005eac4 LR: c00000000005ea44 CTR: 0000000030061b9c
[ ] REGS: c000200007383650 TRAP: 0300   Not tainted  (5.10.50-openpower1)
[ ] MSR:  9000000000009033 <SF,HV,EE,ME,IR,DR,RI,LE>  CR: 44000224  XER: 20040000
[ ] CFAR: c00000000005eaa0 DAR: 0000000000000000 DSISR: 02080000 IRQMASK: 0
[ ] GPR00: c00000000005dd98 c0002000073838e0 c00000000185de00 c000200fff018960
[ ] GPR04: 00000000000000fc 0000000000000003 0000000000000000 0000000000000000
[ ] GPR08: 0000000000000000 0000000000000000 0000000000000000 9000000000001033
[ ] GPR12: 0000000031cb0000 c000000ffffe6a80 c000000000010a58 0000000000000000
[ ] GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000
[ ] GPR20: 0000000000000000 0000000000000000 0000000000000000 c00000000711e200
[ ] GPR24: 0000000000000100 c000200009501120 c00020000cee2800 00000000000003ff
[ ] GPR28: c000200fff018960 0000000000000000 c000200ffcb7fd00 0000000000000000
[ ] NIP [c00000000005eac4] pnv_ioda_setup_pe_res+0x94/0x1a0
[ ] LR [c00000000005ea44] pnv_ioda_setup_pe_res+0x14/0x1a0
[ ] Call Trace:
[ ] [c0002000073838e0] [c00000000005eb98] pnv_ioda_setup_pe_res+0x168/0x1a0 (unreliable)
[ ] [c000200007383970] [c00000000005dd98] pnv_pci_ioda_dma_dev_setup+0x43c/0x970
[ ] [c000200007383a60] [c000000000032cdc] pcibios_bus_add_device+0x78/0x18c
[ ] [c000200007383aa0] [c00000000028f2bc] pci_bus_add_device+0x28/0xbc
[ ] [c000200007383b10] [c00000000028f3a0] pci_bus_add_devices+0x50/0x7c
[ ] [c000200007383b50] [c00000000028f3c4] pci_bus_add_devices+0x74/0x7c
[ ] [c000200007383b90] [c00000000028f3c4] pci_bus_add_devices+0x74/0x7c
[ ] [c000200007383bd0] [c00000000069ad0c] pcibios_init+0xf0/0x104
[ ] [c000200007383c50] [c0000000000106d8] do_one_initcall+0x84/0x1c4
[ ] [c000200007383d20] [c0000000006910b8] kernel_init_freeable+0x264/0x268
[ ] [c000200007383dc0] [c000000000010a68] kernel_init+0x18/0x138
[ ] [c000200007383e20] [c00000000000cbfc] ret_from_kernel_thread+0x5c/0x80
[ ] Instruction dump:
[ ] 7f89e840 409d000c 7fbbf840 409c000c 38210090 4848f448 809c002c e95e0120
[ ] 7ba91764 38a00003 57a7043e 38c00000 <7c8a492e> 5484043e e87e0018 4bff23bd

Hitting the problem is not that easy. It was seen with a (semi-bogus)
PCI device with a class code of 0. The generic PCI framework doesn't
allocate resources in such a case.

The patch is simply skipping resources which are still flagged with
IORESOURCE_UNSET.

We don't have the problem with 64-bit mem resources, as the address of
the resource is checked to be within the range of the 64-bit mmio
window. See pnv_ioda_reserve_dev_m64_pe() and pnv_pci_is_m64().

Reported-by: Andrew Jeffery <andrew@aj.id.au>
Fixes: 23e79425fe7c ("powerpc/powernv: Simplify pnv_ioda_setup_pe_seg()")
Signed-off-by: Frederic Barrat <fbarrat@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230120093215.19496-1-fbarrat@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-03-11 16:43:51 +01:00
Sean Anderson
dab2066c5f powerpc: dts: t208x: Disable 10G on MAC1 and MAC2
[ Upstream commit 8d8bee13ae9e316443c6666286360126a19c8d94 ]

There aren't enough resources to run these ports at 10G speeds. Disable
10G for these ports, reverting to the previous speed.

Fixes: 36926a7d70c2 ("powerpc: dts: t208x: Mark MAC1 and MAC2 as 10G")
Reported-by: Camelia Alexandra Groza <camelia.groza@nxp.com>
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Tested-by: Camelia Groza <camelia.groza@nxp.com>
Link: https://lore.kernel.org/r/20221216172937.2960054-1-sean.anderson@seco.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-25 11:53:26 +01:00
Sean Anderson
eff0e02f7d powerpc: dts: t208x: Mark MAC1 and MAC2 as 10G
[ Upstream commit 36926a7d70c2d462fca1ed85bfee000d17fd8662 ]

On the T208X SoCs, MAC1 and MAC2 support XGMII. Add some new MAC dtsi
fragments, and mark the QMAN ports as 10G.

Fixes: da414bb923d9 ("powerpc/mpc85xx: Add FSL QorIQ DPAA FMan support to the SoC device tree(s)")
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-25 11:53:25 +01:00
Michael Ellerman
8edda487f0 powerpc/imc-pmu: Revert nest_init_lock to being a mutex
commit ad53db4acb415976761d7302f5b02e97f2bd097e upstream.

The recent commit 76d588dddc45 ("powerpc/imc-pmu: Fix use of mutex in
IRQs disabled section") fixed warnings (and possible deadlocks) in the
IMC PMU driver by converting the locking to use spinlocks.

It also converted the init-time nest_init_lock to a spinlock, even
though it's not used at runtime in IRQ disabled sections or while
holding other spinlocks.

This leads to warnings such as:

  BUG: sleeping function called from invalid context at include/linux/percpu-rwsem.h:49
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 1, expected: 0
  CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc2-14719-gf12cd06109f4-dirty #1
  Hardware name: Mambo,Simulated-System POWER9 0x4e1203 opal:v6.6.6 PowerNV
  Call Trace:
    dump_stack_lvl+0x74/0xa8 (unreliable)
    __might_resched+0x178/0x1a0
    __cpuhp_setup_state+0x64/0x1e0
    init_imc_pmu+0xe48/0x1250
    opal_imc_counters_probe+0x30c/0x6a0
    platform_probe+0x78/0x110
    really_probe+0x104/0x420
    __driver_probe_device+0xb0/0x170
    driver_probe_device+0x58/0x180
    __driver_attach+0xd8/0x250
    bus_for_each_dev+0xb4/0x140
    driver_attach+0x34/0x50
    bus_add_driver+0x1e8/0x2d0
    driver_register+0xb4/0x1c0
    __platform_driver_register+0x38/0x50
    opal_imc_driver_init+0x2c/0x40
    do_one_initcall+0x80/0x360
    kernel_init_freeable+0x310/0x3b8
    kernel_init+0x30/0x1a0
    ret_from_kernel_thread+0x5c/0x64

Fix it by converting nest_init_lock back to a mutex, so that we can call
sleeping functions while holding it. There is no interaction between
nest_init_lock and the runtime spinlocks used by the actual PMU routines.

Fixes: 76d588dddc45 ("powerpc/imc-pmu: Fix use of mutex in IRQs disabled section")
Tested-by: Kajol Jain<kjain@linux.ibm.com>
Reviewed-by: Kajol Jain<kjain@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230130014401.540543-1-mpe@ellerman.id.au
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-22 12:50:29 +01:00
Eric W. Biederman
9a18c9c833 exit: Add and use make_task_dead.
commit 0e25498f8cd43c1b5aa327f373dd094e9a006da7 upstream.

There are two big uses of do_exit.  The first is it's design use to be
the guts of the exit(2) system call.  The second use is to terminate
a task after something catastrophic has happened like a NULL pointer
in kernel code.

Add a function make_task_dead that is initialy exactly the same as
do_exit to cover the cases where do_exit is called to handle
catastrophic failure.  In time this can probably be reduced to just a
light wrapper around do_task_dead. For now keep it exactly the same so
that there will be no behavioral differences introducing this new
concept.

Replace all of the uses of do_exit that use it for catastraphic
task cleanup with make_task_dead to make it clear what the code
is doing.

As part of this rename rewind_stack_do_exit
rewind_stack_and_make_dead.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-02-06 07:52:49 +01:00
Kajol Jain
d0c6d2a310 powerpc/imc-pmu: Fix use of mutex in IRQs disabled section
commit 76d588dddc459fefa1da96e0a081a397c5c8e216 upstream.

Current imc-pmu code triggers a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP
and CONFIG_PROVE_LOCKING enabled, while running a thread_imc event.

Command to trigger the warning:
  # perf stat -e thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/ sleep 5

   Performance counter stats for 'sleep 5':

                   0      thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/

         5.002117947 seconds time elapsed

         0.000131000 seconds user
         0.001063000 seconds sys

Below is snippet of the warning in dmesg:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2869, name: perf-exec
  preempt_count: 2, expected: 0
  4 locks held by perf-exec/2869:
   #0: c00000004325c540 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0x64/0xa90
   #1: c00000004325c5d8 (&sig->exec_update_lock){++++}-{3:3}, at: begin_new_exec+0x460/0xef0
   #2: c0000003fa99d4e0 (&cpuctx_lock){-...}-{2:2}, at: perf_event_exec+0x290/0x510
   #3: c000000017ab8418 (&ctx->lock){....}-{2:2}, at: perf_event_exec+0x29c/0x510
  irq event stamp: 4806
  hardirqs last  enabled at (4805): [<c000000000f65b94>] _raw_spin_unlock_irqrestore+0x94/0xd0
  hardirqs last disabled at (4806): [<c0000000003fae44>] perf_event_exec+0x394/0x510
  softirqs last  enabled at (0): [<c00000000013c404>] copy_process+0xc34/0x1ff0
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 36 PID: 2869 Comm: perf-exec Not tainted 6.2.0-rc2-00011-g1247637727f2 #61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    __might_resched+0x2f8/0x310
    __mutex_lock+0x6c/0x13f0
    thread_imc_event_add+0xf4/0x1b0
    event_sched_in+0xe0/0x210
    merge_sched_in+0x1f0/0x600
    visit_groups_merge.isra.92.constprop.166+0x2bc/0x6c0
    ctx_flexible_sched_in+0xcc/0x140
    ctx_sched_in+0x20c/0x2a0
    ctx_resched+0x104/0x1c0
    perf_event_exec+0x340/0x510
    begin_new_exec+0x730/0xef0
    load_elf_binary+0x3f8/0x1e10
  ...
  do not call blocking ops when !TASK_RUNNING; state=2001 set at [<00000000fd63e7cf>] do_nanosleep+0x60/0x1a0
  WARNING: CPU: 36 PID: 2869 at kernel/sched/core.c:9912 __might_sleep+0x9c/0xb0
  CPU: 36 PID: 2869 Comm: sleep Tainted: G        W          6.2.0-rc2-00011-g1247637727f2 #61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  NIP:  c000000000194a1c LR: c000000000194a18 CTR: c000000000a78670
  REGS: c00000004d2134e0 TRAP: 0700   Tainted: G        W           (6.2.0-rc2-00011-g1247637727f2)
  MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  CR: 48002824  XER: 00000000
  CFAR: c00000000013fb64 IRQMASK: 1

The above warning triggered because the current imc-pmu code uses mutex
lock in interrupt disabled sections. The function mutex_lock()
internally calls __might_resched(), which will check if IRQs are
disabled and in case IRQs are disabled, it will trigger the warning.

Fix the issue by changing the mutex lock to spinlock.

Fixes: 8f95faaac56c ("powerpc/powernv: Detect and create IMC device")
Reported-by: Michael Petlan <mpetlan@redhat.com>
Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kajol Jain <kjain@linux.ibm.com>
[mpe: Fix comments, trim oops in change log, add reported-by tags]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20230106065157.182648-1-kjain@linux.ibm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-18 11:42:03 +01:00
Nathan Lynch
515959eb49 powerpc/rtas: avoid scheduling in rtas_os_term()
[ Upstream commit 6c606e57eecc37d6b36d732b1ff7e55b7dc32dd4 ]

It's unsafe to use rtas_busy_delay() to handle a busy status from
the ibm,os-term RTAS function in rtas_os_term():

Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
BUG: sleeping function called from invalid context at arch/powerpc/kernel/rtas.c:618
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 1, name: swapper/0
preempt_count: 2, expected: 0
CPU: 7 PID: 1 Comm: swapper/0 Tainted: G      D            6.0.0-rc5-02182-gf8553a572277-dirty #9
Call Trace:
[c000000007b8f000] [c000000001337110] dump_stack_lvl+0xb4/0x110 (unreliable)
[c000000007b8f040] [c0000000002440e4] __might_resched+0x394/0x3c0
[c000000007b8f0e0] [c00000000004f680] rtas_busy_delay+0x120/0x1b0
[c000000007b8f100] [c000000000052d04] rtas_os_term+0xb8/0xf4
[c000000007b8f180] [c0000000001150fc] pseries_panic+0x50/0x68
[c000000007b8f1f0] [c000000000036354] ppc_panic_platform_handler+0x34/0x50
[c000000007b8f210] [c0000000002303c4] notifier_call_chain+0xd4/0x1c0
[c000000007b8f2b0] [c0000000002306cc] atomic_notifier_call_chain+0xac/0x1c0
[c000000007b8f2f0] [c0000000001d62b8] panic+0x228/0x4d0
[c000000007b8f390] [c0000000001e573c] do_exit+0x140c/0x1420
[c000000007b8f480] [c0000000001e586c] make_task_dead+0xdc/0x200

Use rtas_busy_delay_time() instead, which signals without side effects
whether to attempt the ibm,os-term RTAS call again.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221118150751.469393-5-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 11:41:43 +01:00
Nathan Lynch
c2fa91abf2 powerpc/rtas: avoid device tree lookups in rtas_os_term()
[ Upstream commit ed2213bfb192ab51f09f12e9b49b5d482c6493f3 ]

rtas_os_term() is called during panic. Its behavior depends on a couple
of conditions in the /rtas node of the device tree, the traversal of
which entails locking and local IRQ state changes. If the kernel panics
while devtree_lock is held, rtas_os_term() as currently written could
hang.

Instead of discovering the relevant characteristics at panic time,
cache them in file-static variables at boot. Note the lookup for
"ibm,extended-os-term" is converted to of_property_read_bool() since it
is a boolean property, not an RTAS function token.

Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
[mpe: Incorporate suggested change from Nick]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221118150751.469393-4-nathanl@linux.ibm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2023-01-18 11:41:43 +01:00