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commit 10835c854685393a921b68f529bf740fa7c9984d upstream.
On parisc the privilege level of a process is stored in the lowest two bits of
the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0
for the kernel and privilege level 3 for user-space. So userspace should not be
allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege
level to e.g. 0 to try to gain kernel privileges.
This patch prevents such modifications by always setting the two lowest bits to
one (which relates to privilege level 3 for user-space) if IAOQ0 or IAOQ1 are
modified via ptrace calls in the native and compat ptrace paths.
Link: https://bugs.gentoo.org/481768
Reported-by: Jeroen Roovers <jer@gentoo.org>
Cc: <stable@vger.kernel.org>
Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 34c32fc603311a72cb558e5e337555434f64c27b upstream.
On parisc the privilege level of a process is stored in the lowest two bits of
the instruction pointers (IAOQ0 and IAOQ1). On Linux we use privilege level 0
for the kernel and privilege level 3 for user-space. So userspace should not be
allowed to modify IAOQ0 or IAOQ1 of a ptraced process to change it's privilege
level to e.g. 0 to try to gain kernel privileges.
This patch prevents such modifications in the regset support functions by
always setting the two lowest bits to one (which relates to privilege level 3
for user-space) if IAOQ0 or IAOQ1 are modified via ptrace regset calls.
Link: https://bugs.gentoo.org/481768
Cc: <stable@vger.kernel.org> # v4.7+
Tested-by: Rolf Eike Beer <eike-kernel@sf-tec.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1829dda0e87f4462782ca81be474c7890efe31ce upstream.
LEVEL is a very common word, and now after many years it suddenly
clashed with another LEVEL define in the DRBD code.
Rename it to PA_ASM_LEVEL instead.
Reported-by: kbuild test robot <lkp@intel.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5ffa8518851f1401817c15d2a7eecc0373c26ff9 upstream.
When running on qemu we know that the (emulated) cr16 cpu-internal
clocks are syncronized. So let's use them unconditionally on qemu.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d006e95b5561f708d0385e9677ffe2c46f2ae345 upstream.
While adding LASI support to QEMU, I noticed that the QEMU detection in
the kernel happens much too late. For example, when a LASI chip is found
by the kernel, it registers the LASI LED driver as well. But when we
run on QEMU it makes sense to avoid spending unnecessary CPU cycles, so
we need to access the running_on_QEMU flag earlier than before.
This patch now makes the QEMU detection the fist task of the Linux
kernel by moving it to where the kernel enters the C-coding.
Fixes: 310d82784fb4 ("parisc: qemu idle sleep support")
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # v4.14+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b7dc5a071ddf69c0350396b203cba32fe5bab510 upstream.
Commit 910cd32e552e ("parisc: Fix and enable seccomp filter support")
introduced a regression in ptrace-based syscall tampering: when tracer
changes syscall number to -1, the kernel fails to initialize %r28 with
-ENOSYS and subsequently fails to return the error code of the failed
syscall to userspace.
This erroneous behaviour could be observed with a simple strace syscall
fault injection command which is expected to print something like this:
$ strace -a0 -ewrite -einject=write:error=enospc echo hello
write(1, "hello\n", 6) = -1 ENOSPC (No space left on device) (INJECTED)
write(2, "echo: ", 6) = -1 ENOSPC (No space left on device) (INJECTED)
write(2, "write error", 11) = -1 ENOSPC (No space left on device) (INJECTED)
write(2, "\n", 1) = -1 ENOSPC (No space left on device) (INJECTED)
+++ exited with 1 +++
After commit 910cd32e552ea09caa89cdbe328e468979b030dd it loops printing
something like this instead:
write(1, "hello\n", 6../strace: Failed to tamper with process 12345: unexpectedly got no error (return value 0, error 0)
) = 0 (INJECTED)
This bug was found by strace test suite.
Fixes: 910cd32e552e ("parisc: Fix and enable seccomp filter support")
Cc: stable@vger.kernel.org # v4.5+
Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>
Tested-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 99a3ae51d557d8e38a7aece65678a31f9db215ee ]
In the C-code we need to put the physical address of the hpmc handler in
the interrupt vector table (IVA) in order to get HPMCs working. Since
on parisc64 function pointers are indirect (in fact they are function
descriptors) we instead export the address as variable and not as
function.
This reverts a small part of commit f39cce654f9a ("parisc: Add
cfi_startproc and cfi_endproc to assembly code").
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> [4.9+]
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d5654e156bc4d68a87bbaa6d7e020baceddf6e68 ]
Make sure that the HPMC (High Priority Machine Check) handler is 16-byte
aligned and that it's length in the IVT is a multiple of 16 bytes.
Otherwise PDC may decide not to call the HPMC crash handler.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 0ed9d3de5f8f97e6efd5ca0e3377cab5f0451ead ]
The os_hpmc_size variable sometimes wasn't aligned at word boundary and thus
triggered the unaligned fault handler at startup.
Fix it by aligning it properly.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.14+
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 7797167ffde1f00446301cb22b37b7c03194cfaf upstream.
Now that we use a sync prior to releasing the locks in syscall.S, we don't need
the PA 2.0 ordered stores used to release some locks. Using an ordered store,
potentially slows the release and subsequent code.
There are a number of other ordered stores and loads that serve no purpose. I
have converted these to normal stores.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit fedb8da96355f5f64353625bf96dc69423ad1826 upstream.
For years I thought all parisc machines executed loads and stores in
order. However, Jeff Law recently indicated on gcc-patches that this is
not correct. There are various degrees of out-of-order execution all the
way back to the PA7xxx processor series (hit-under-miss). The PA8xxx
series has full out-of-order execution for both integer operations, and
loads and stores.
This is described in the following article:
http://web.archive.org/web/20040214092531/http://www.cpus.hp.com/technical_references/advperf.shtml
For this reason, we need to define mb() and to insert a memory barrier
before the store unlocking spinlocks. This ensures that all memory
accesses are complete prior to unlocking. The ldcw instruction performs
the same function on entry.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.0+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 615b2665fd20c327b631ff1e79426775de748094 upstream.
As found by the ubsan checker, the value of the 'index' variable can be
out of range for the bc[] array:
UBSAN: Undefined behaviour in arch/parisc/kernel/drivers.c:655:21
index 6 is out of range for type 'char [6]'
Backtrace:
[<104fa850>] __ubsan_handle_out_of_bounds+0x68/0x80
[<1019d83c>] check_parent+0xc0/0x170
[<1019d91c>] descend_children+0x30/0x6c
[<1059e164>] device_for_each_child+0x60/0x98
[<1019cd54>] parse_tree_node+0x40/0x54
[<1019d86c>] check_parent+0xf0/0x170
[<1019d91c>] descend_children+0x30/0x6c
[<1059e164>] device_for_each_child+0x60/0x98
[<1019d938>] descend_children+0x4c/0x6c
[<1059e164>] device_for_each_child+0x60/0x98
[<1019cd54>] parse_tree_node+0x40/0x54
[<1019cffc>] hwpath_to_device+0xa4/0xc4
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9ef0f88fe5466c2ca1d2975549ba6be502c464c1 upstream.
Just when I had decided that flush_cache_range() was always called with
a valid context, Helge reported two cases where the
"BUG_ON(!vma->vm_mm->context);" was hit on the phantom buildd:
kernel BUG at /mnt/sdb6/linux/linux-4.15.4/arch/parisc/kernel/cache.c:587!
CPU: 1 PID: 3254 Comm: kworker/1:2 Tainted: G D 4.15.0-1-parisc64-smp #1 Debian 4.15.4-1+b1
Workqueue: events free_ioctx
IAOQ[0]: flush_cache_range+0x164/0x168
IAOQ[1]: flush_cache_page+0x0/0x1c8
RP(r2): unmap_page_range+0xae8/0xb88
Backtrace:
[<00000000404a6980>] unmap_page_range+0xae8/0xb88
[<00000000404a6ae0>] unmap_single_vma+0xc0/0x188
[<00000000404a6cdc>] zap_page_range_single+0x134/0x1f8
[<00000000404a702c>] unmap_mapping_range+0x1cc/0x208
[<0000000040461518>] truncate_pagecache+0x98/0x108
[<0000000040461624>] truncate_setsize+0x9c/0xb8
[<00000000405d7f30>] put_aio_ring_file+0x80/0x100
[<00000000405d803c>] aio_free_ring+0x8c/0x290
[<00000000405d82c0>] free_ioctx+0x80/0x180
[<0000000040284e6c>] process_one_work+0x21c/0x668
[<00000000402854c4>] worker_thread+0x20c/0x778
[<0000000040291d44>] kthread+0x2d4/0x2e0
[<0000000040204020>] end_fault_vector+0x20/0xc0
This indicates that we need to handle the no context case in
flush_cache_range() as we do in flush_cache_mm().
In thinking about this, I realized that we don't need to flush the TLB
when there is no context. So, I added context checks to the large flush
cases in flush_cache_mm() and flush_cache_range(). The large flush case
occurs frequently in flush_cache_mm() and the change should improve fork
performance.
The v2 version of this change removes the BUG_ON from flush_cache_page()
by skipping the TLB flush when there is no context. I also added code
to flush the TLB in flush_cache_mm() and flush_cache_range() when we
have a context that's not current. Now all three routines handle TLB
flushes in a similar manner.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0adb24e03a124b79130c9499731936b11ce2677d upstream.
The change to flush_kernel_vmap_range() wasn't sufficient to avoid the
SMP stalls. The problem is some drivers call these routines with
interrupts disabled. Interrupts need to be enabled for flush_tlb_all()
and flush_cache_all() to work. This version adds checks to ensure
interrupts are not disabled before calling routines that need IPI
interrupts. When interrupts are disabled, we now drop into slower code.
The attached change fixes the ordering of cache and TLB flushes in
several cases. When we flush the cache using the existing PTE/TLB
entries, we need to flush the TLB after doing the cache flush. We don't
need to do this when we flush the entire instruction and data caches as
these flushes don't use the existing TLB entries. The same is true for
tmpalias region flushes.
The flush_kernel_vmap_range() and invalidate_kernel_vmap_range()
routines have been updated.
Secondly, we added a new purge_kernel_dcache_range_asm() routine to
pacache.S and use it in invalidate_kernel_vmap_range(). Nominally,
purges are faster than flushes as the cache lines don't have to be
written back to memory.
Hopefully, this is sufficient to resolve the remaining problems due to
cache speculation. So far, testing indicates that this is the case. I
did work up a patch using tmpalias flushes, but there is a performance
hit because we need the physical address for each page, and we also need
to sequence access to the tmpalias flush code. This increases the
probability of stalls.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 310d82784fb4d60c80569f5ca9f53a7f3bf1d477 upstream.
Add qemu idle sleep support when running under qemu with SeaBIOS PDC
firmware.
Like the power architecture we use the "or" assembler instructions,
which translate to nops on real hardware, to indicate that qemu shall
idle sleep.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 88776c0e70be0290f8357019d844aae15edaa967 upstream.
Qemu for PARISC reported on a 32bit SMP parisc kernel strange failures
about "Not-handled unaligned insn 0x0e8011d6 and 0x0c2011c9."
Those opcodes evaluate to the ldcw() assembly instruction which requires
(on 32bit) an alignment of 16 bytes to ensure atomicity.
As it turns out, qemu is correct and in our assembly code in entry.S and
pacache.S we don't pay attention to the required alignment.
This patch fixes the problem by aligning the lock offset in assembly
code in the same manner as we do in our C-code.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 05f016d2ca7a4fab99d5d5472168506ddf95e74f upstream.
As noted by Christoph Biedl, passing a pointer size of 4 in the new CAS
implementation causes a kernel crash. The attached patch corrects the
off by one error in the argument validity check.
In reviewing the code, I noticed that we only perform word operations
with the pointer size argument. The subi instruction intentionally uses
a word condition on 64-bit kernels. Nullification was used instead of a
cmpib instruction as the branch should never be taken. The shlw
pseudo-operation generates a depw,z instruction and it clears the target
before doing a shift left word deposit. Thus, we don't need to clip the
upper 32 bits of this argument on 64-bit kernels.
Tested with a gcc testsuite run with a 64-bit kernel. The gcc atomic
code in libgcc is the only direct user of the new CAS implementation
that I am aware of.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 374b3bf8e8b519f61eb9775888074c6e46b3bf0c upstream.
As discussed on the debian-hppa list, double-wordcompare and exchange
operations fail on 32-bit kernels. Looking at the code, I realized that
the ",ma" completer does the wrong thing in the "ldw,ma 4(%r26), %r29"
instruction. This increments %r26 and causes the following store to
write to the wrong location.
Note by Helge Deller:
The patch applies cleanly to stable kernel series if this upstream
commit is merged in advance:
f4125cfdb300 ("parisc: Avoid trashing sr2 and sr3 in LWS code").
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Tested-by: Christoph Biedl <debian.axhn@manchmal.in-ulm.de>
Fixes: 89206491201c ("parisc: Implement new LWS CAS supporting 64 bit operations.")
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 13d57093c141db2036364d6be35e394fc5b64728 upstream.
In testing James' patch to drivers/parisc/pdc_stable.c, I hit the BUG
statement in flush_cache_range() during a system shutdown:
kernel BUG at arch/parisc/kernel/cache.c:595!
CPU: 2 PID: 6532 Comm: kworker/2:0 Not tainted 4.13.0-rc2+ #1
Workqueue: events free_ioctx
IAOQ[0]: flush_cache_range+0x144/0x148
IAOQ[1]: flush_cache_page+0x0/0x1a8
RP(r2): flush_cache_range+0xec/0x148
Backtrace:
[<00000000402910ac>] unmap_page_range+0x84/0x880
[<00000000402918f4>] unmap_single_vma+0x4c/0x60
[<0000000040291a18>] zap_page_range_single+0x110/0x160
[<0000000040291c34>] unmap_mapping_range+0x174/0x1a8
[<000000004026ccd8>] truncate_pagecache+0x50/0xa8
[<000000004026cd84>] truncate_setsize+0x54/0x70
[<000000004033d534>] put_aio_ring_file+0x44/0xb0
[<000000004033d5d8>] aio_free_ring+0x38/0x140
[<000000004033d714>] free_ioctx+0x34/0xa8
[<00000000401b0028>] process_one_work+0x1b8/0x4d0
[<00000000401b04f4>] worker_thread+0x1b4/0x648
[<00000000401b9128>] kthread+0x1b0/0x208
[<0000000040150020>] end_fault_vector+0x20/0x28
[<0000000040639518>] nf_ip_reroute+0x50/0xa8
[<0000000040638ed0>] nf_ip_route+0x10/0x78
[<0000000040638c90>] xfrm4_mode_tunnel_input+0x180/0x1f8
CPU: 2 PID: 6532 Comm: kworker/2:0 Not tainted 4.13.0-rc2+ #1
Workqueue: events free_ioctx
Backtrace:
[<0000000040163bf0>] show_stack+0x20/0x38
[<0000000040688480>] dump_stack+0xa8/0x120
[<0000000040163dc4>] die_if_kernel+0x19c/0x2b0
[<0000000040164d0c>] handle_interruption+0xa24/0xa48
This patch modifies flush_cache_range() to handle non current contexts.
In as much as this occurs infrequently, the simplest approach is to
flush the entire cache when this happens.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 56188832a50f09998cb570ba3771a1d25c193c0e upstream.
Some machines can't power off the machine, so disable the lockup detectors to
avoid this watchdog BUG to show up every few seconds:
watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [systemd-shutdow:1]
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 56008c04ebc099940021b714da2d7779117cf6a7 upstream.
It's always bothered me that we only disable preemption in
copy_user_page around the call to flush_dcache_page_asm.
This patch extends this to after the copy.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit ae7a609c34b6fb12328c553b5f9aab26ae74a28e upstream.
Helge noticed that we flush the TLB page in flush_cache_page but not in
flush_cache_range or flush_cache_mm.
For a long time, we have had random segmentation faults building
packages on machines with PA8800/8900 processors. These machines only
support equivalent aliases. We don't see these faults on machines that
don't require strict coherency. So, it appears TLB speculation
sometimes leads to cache corruption on machines that require coherency.
This patch adds TLB flushes to flush_cache_range and flush_cache_mm when
coherency is required. We only flush the TLB in flush_cache_page when
coherency is required.
The patch also optimizes flush_cache_range. It turns out we always have
the right context to use flush_user_dcache_range_asm and
flush_user_icache_range_asm.
The patch has been tested for some time on rp3440, rp3410 and A500-44.
It's been boot tested on c8000. No random segmentation faults were
observed during testing.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit b0f94efd5aa8daa8a07d7601714c2573266cd4c9 upstream.
Architectures with a compat syscall table must put compat_sys_keyctl()
in it, not sys_keyctl(). The parisc architecture was not doing this;
fix it.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Helge Deller <deller@gmx.de>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream.
Stack guard page is a useful feature to reduce a risk of stack smashing
into a different mapping. We have been using a single page gap which
is sufficient to prevent having stack adjacent to a different mapping.
But this seems to be insufficient in the light of the stack usage in
userspace. E.g. glibc uses as large as 64kB alloca() in many commonly
used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX]
which is 256kB or stack strings with MAX_ARG_STRLEN.
This will become especially dangerous for suid binaries and the default
no limit for the stack size limit because those applications can be
tricked to consume a large portion of the stack and a single glibc call
could jump over the guard page. These attacks are not theoretical,
unfortunatelly.
Make those attacks less probable by increasing the stack guard gap
to 1MB (on systems with 4k pages; but make it depend on the page size
because systems with larger base pages might cap stack allocations in
the PAGE_SIZE units) which should cover larger alloca() and VLA stack
allocations. It is obviously not a full fix because the problem is
somehow inherent, but it should reduce attack space a lot.
One could argue that the gap size should be configurable from userspace,
but that can be done later when somebody finds that the new 1MB is wrong
for some special case applications. For now, add a kernel command line
option (stack_guard_gap) to specify the stack gap size (in page units).
Implementation wise, first delete all the old code for stack guard page:
because although we could get away with accounting one extra page in a
stack vma, accounting a larger gap can break userspace - case in point,
a program run with "ulimit -S -v 20000" failed when the 1MB gap was
counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK
and strict non-overcommit mode.
Instead of keeping gap inside the stack vma, maintain the stack guard
gap as a gap between vmas: using vm_start_gap() in place of vm_start
(or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few
places which need to respect the gap - mainly arch_get_unmapped_area(),
and and the vma tree's subtree_gap support for that.
Original-patch-by: Oleg Nesterov <oleg@redhat.com>
Original-patch-by: Michal Hocko <mhocko@suse.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[wt: backport to 4.11: adjust context]
[wt: backport to 4.9: adjust context ; kernel doc was not in admin-guide]
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 476e75a44b56038bee9207242d4bc718f6b4de06 upstream.
Commit 73580dac7618 ("parisc: Fix system shutdown halt") introduced an endless
loop for systems which don't provide a software power off function. But the
soft lockup detector will detect this and report stalled CPUs after some time.
Avoid those unwanted warnings by disabling the soft lockup detector.
Fixes: 73580dac7618 ("parisc: Fix system shutdown halt")
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d19f5e41b344a057bb2450024a807476f30978d2 upstream.
Al Viro noticed that userspace accesses via get_user()/put_user() can be
simplified a lot with regard to usage of the exception handling.
This patch implements a fixup routine for get_user() and put_user() in such
that the exception handler will automatically load -EFAULT into the register
%r8 (the error value) in case on a fault on userspace. Additionally the fixup
routine will zero the target register on fault in case of a get_user() call.
The target register is extracted out of the faulting assembly instruction.
This patch brings a few benefits over the old implementation:
1. Exception handling gets much cleaner, easier and smaller in size.
2. Helper functions like fixup_get_user_skip_1 (all of fixup.S) can be dropped.
3. No need to hardcode %r9 as target register for get_user() any longer. This
helps the compiler register allocator and thus creates less assembler
statements.
4. No dependency on the exception_data contents any longer.
5. Nested faults will be handled cleanly.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 73580dac7618e4bcd21679f553cf3c97323fec46 upstream.
On those parisc machines which don't provide a software power off
function, the system currently kills the init process at the end of a
shutdown and unexpectedly restarts insteads of halting.
Fix it by adding a loop which will not return.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 316ec0624f951166daedbe446988ef92ae72b59f upstream.
The previously submitted patch did not resolve the random segmentation
faults observed on the phantom buildd system. There are still
unresolved problems with the Debian 4.8 and 4.9 kernels on C8000.
The attached patch removes the flush of the offset map pages and does a
whole data cache flush for large ranges. No other arch flushes the
offset map in these routines as far as I can tell.
I have not observed any random segmentation faults on rp3440 in two
weeks of testing with 4.10.0 and 4.10.1.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 41744213602a206f24adcb4a2b7551db3c700e72 upstream.
The cr16 interval timer of each CPU is not syncronized to other cr16
timers in other CPUs in a SMP system. So, delay the registration of the
cr16 clocksource until all CPUs have been detected and then - if we are
on a SMP machine - mark the cr16 clocksource as unstable and lower it's
rating before registering it at the clocksource framework.
This patch fixes the stalled CPU warnings which we have seen since
introduction of the cr16 clocksource.
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
At bootup we run measurements to calculate the best threshold for when we
should be using full TLB flushes instead of just flushing a specific amount of
TLB entries. This performance test is run over the kernel text segment.
But running this TLB performance test on the kernel text segment turned out to
crash some SMP machines when the kernel text pages were mapped as huge pages.
To avoid those crashes this patch simply skips this test on some SMP machines
and calculates an optimal threshold based on the maximum number of available
TLB entries and number of online CPUs.
On a technical side, this seems to happen:
The TLB measurement code uses flush_tlb_kernel_range() to flush specific TLB
entries with a page size of 4k (pdtlb 0(sr1,addr)). On UP systems this purge
instruction seems to work without problems even if the pages were mapped as
huge pages. But on SMP systems the TLB purge instruction is broadcasted to
other CPUs. Those CPUs then crash the machine because the page size is not as
expected. C8000 machines with PA8800/PA8900 CPUs were not affected by this
problem, because the required cache coherency prohibits to use huge pages at
all. Sadly I didn't found any documentation about this behaviour, so this
finding is purely based on testing with phyiscal SMP machines (A500-44 and
J5000, both were 2-way boxes).
Cc: <stable@vger.kernel.org> # v3.18+
Signed-off-by: Helge Deller <deller@gmx.de>
We have four routines in pacache.S that use temporary alias pages:
copy_user_page_asm(), clear_user_page_asm(), flush_dcache_page_asm() and
flush_icache_page_asm(). copy_user_page_asm() and clear_user_page_asm()
don't purge the TLB entry used for the operation.
flush_dcache_page_asm() and flush_icache_page_asm do purge the entry.
Presumably, this was thought to optimize TLB use. However, the
operation is quite heavy weight on PA 1.X processors as we need to take
the TLB lock and a TLB broadcast is sent to all processors.
This patch removes the purges from flush_dcache_page_asm() and
flush_icache_page_asm.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Helge Deller <deller@gmx.de>
This is the second issue I noticed in reviewing the parisc TLB code.
The fic instruction may use either the instruction or data TLB in
flushing the instruction cache. Thus, on machines with a split TLB, we
should also flush the data TLB after setting up the temporary alias
registers.
Although this has no functional impact, I changed the pdtlb and pitlb
instructions to consistently use the index register %r0. These
instructions do not support integer displacements.
Tested on rp3440 and c8000.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Helge Deller <deller@gmx.de>
We are still troubled by occasional random segmentation faults and
memory memory corruption on SMP machines. The causes quite a few
package builds to fail on the Debian buildd machines for parisc. When
gcc-6 failed to build three times in a row, I looked again at the TLB
related code. I found a couple of issues. This is the first.
In general, we need to ensure page table updates and corresponding TLB
purges are atomic. The attached patch fixes an instance in pci-dma.c
where the page table update was not guarded by the TLB lock.
Tested on rp3440 and c8000. So far, no further random segmentation
faults have been observed.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Cc: <stable@vger.kernel.org> # v3.16+
Signed-off-by: Helge Deller <deller@gmx.de>
Drop the open-coded sched_clock() function and replace it by the provided
GENERIC_SCHED_CLOCK implementation. We have seen quite some hung tasks in the
past, which seem to be fixed by this patch.
Signed-off-by: Helge Deller <deller@gmx.de>
Cc: <stable@vger.kernel.org> # v4.7+
Signed-off-by: Helge Deller <deller@gmx.de>
We have one critical section in the syscall entry path in which we switch from
the userspace stack to kernel stack. In the event of an external interrupt, the
interrupt code distinguishes between those two states by analyzing the value of
sr7. If sr7 is zero, it uses the kernel stack. Therefore it's important, that
the value of sr7 is in sync with the currently enabled stack.
This patch now disables interrupts while executing the critical section. This
prevents the interrupt handler to possibly see an inconsistent state which in
the worst case can lead to crashes.
Interestingly, in the syscall exit path interrupts were already disabled in the
critical section which switches back to the userspace stack.
Cc: <stable@vger.kernel.org>
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
There is no need to trash sr2 and sr3 in the Light-weight syscall (LWS). sr2
already points to kernel space (it's zero in userspace, otherwise syscalls
wouldn't work), and since the LWS code is executed in userspace, we can simply
ignore to preload sr3.
Signed-off-by: John David Anglin <dave.anglin@bell.net>
Signed-off-by: Helge Deller <deller@gmx.de>
Recent changes to printk require KERN_CONT uses to continue logging messages.
So add KERN_CONT to output of device inventory.
Signed-off-by: Helge Deller <deller@gmx.de>
Pull parisc fixes from Helge Deller:
"Some final updates and fixes for this merge window for the parisc
architecture. Changes include:
- Fix boot problems with new memblock allocator on rp3410 machine
- Increase initial kernel mapping size for 32- and 64-bit kernels,
this allows to boot bigger kernels which have many modules built-in
- Fix kernel layout regarding __gp and move exception table into RO
section
- Show trap names in crashes, use extable.h header instead of
module.h"
* 'parisc-4.9-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
parisc: Show trap name in kernel crash
parisc: Zero-initialize newly alloced memblock
parisc: Move exception table into read-only section
parisc: Fix kernel memory layout regarding position of __gp
parisc: Increase initial kernel mapping size
parisc: Migrate exception table users off module.h and onto extable.h
Pull misc vfs updates from Al Viro:
"Assorted misc bits and pieces.
There are several single-topic branches left after this (rename2
series from Miklos, current_time series from Deepa Dinamani, xattr
series from Andreas, uaccess stuff from from me) and I'd prefer to
send those separately"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits)
proc: switch auxv to use of __mem_open()
hpfs: support FIEMAP
cifs: get rid of unused arguments of CIFSSMBWrite()
posix_acl: uapi header split
posix_acl: xattr representation cleanups
fs/aio.c: eliminate redundant loads in put_aio_ring_file
fs/internal.h: add const to ns_dentry_operations declaration
compat: remove compat_printk()
fs/buffer.c: make __getblk_slow() static
proc: unsigned file descriptors
fs/file: more unsigned file descriptors
fs: compat: remove redundant check of nr_segs
cachefiles: Fix attempt to read i_blocks after deleting file [ver #2]
cifs: don't use memcpy() to copy struct iov_iter
get rid of separate multipage fault-in primitives
fs: Avoid premature clearing of capabilities
fs: Give dentry to inode_change_ok() instead of inode
fuse: Propagate dentry down to inode_change_ok()
ceph: Propagate dentry down to inode_change_ok()
xfs: Propagate dentry down to inode_change_ok()
...
Architecturally we need to keep __gp below 0x1000000.
But because of ftrace and tracepoint support, the RO_DATA_SECTION now gets much
bigger than it was before. By moving the linkage tables before RO_DATA_SECTION
we can avoid that __gp gets positioned at a too high address.
Cc: stable@vger.kernel.org # 4.4+
Signed-off-by: Helge Deller <deller@gmx.de>
Merge updates from Andrew Morton:
- fsnotify updates
- ocfs2 updates
- all of MM
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (127 commits)
console: don't prefer first registered if DT specifies stdout-path
cred: simpler, 1D supplementary groups
CREDITS: update Pavel's information, add GPG key, remove snail mail address
mailmap: add Johan Hovold
.gitattributes: set git diff driver for C source code files
uprobes: remove function declarations from arch/{mips,s390}
spelling.txt: "modeled" is spelt correctly
nmi_backtrace: generate one-line reports for idle cpus
arch/tile: adopt the new nmi_backtrace framework
nmi_backtrace: do a local dump_stack() instead of a self-NMI
nmi_backtrace: add more trigger_*_cpu_backtrace() methods
min/max: remove sparse warnings when they're nested
Documentation/filesystems/proc.txt: add more description for maps/smaps
mm, proc: fix region lost in /proc/self/smaps
proc: fix timerslack_ns CAP_SYS_NICE check when adjusting self
proc: add LSM hook checks to /proc/<tid>/timerslack_ns
proc: relax /proc/<tid>/timerslack_ns capability requirements
meminfo: break apart a very long seq_printf with #ifdefs
seq/proc: modify seq_put_decimal_[u]ll to take a const char *, not char
proc: faster /proc/*/status
...
