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  1. 19 10月, 2017 1 次提交
  3. 23 9月, 2017 6 次提交
  5. 14 9月, 2017 1 次提交
  7. 22 8月, 2017 7 次提交
  9. 31 7月, 2017 2 次提交
    • H
      parisc: Increase thread and stack size to 32kb · 8f8201df
      由 Helge Deller 提交于 
      Since kernel 4.11 the thread and irq stacks on parisc randomly overflow
the default size of 16k. The reason why stack usage suddenly grew is yet
unknown.
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.11+
Signed-off-by: NHelge Deller <deller@gmx.de>
      8f8201df
    • J
      parisc: Handle vma's whose context is not current in flush_cache_range · 13d57093
      由 John David Anglin 提交于 
      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: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: NHelge Deller <deller@gmx.de>
      13d57093
  11. 26 7月, 2017 6 次提交
    • J
      parisc: Extend disabled preemption in copy_user_page · 56008c04
      由 John David Anglin 提交于 
      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: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: NHelge Deller <deller@gmx.de>
      56008c04
    • J
      parisc: Prevent TLB speculation on flushed pages on CPUs that only support equivalent aliases · ae7a609c
      由 John David Anglin 提交于 
      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: NJohn David Anglin <dave.anglin@bell.net>
Cc: stable@vger.kernel.org # 4.9+
Signed-off-by: NHelge Deller <deller@gmx.de>
      ae7a609c
    • H
      parisc: Suspend lockup detectors before system halt · 56188832
      由 Helge Deller 提交于 
      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: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.9+
      56188832
    • H
      parisc: Show DIMM slot number which holds broken memory module · c46bafc4
      由 Helge Deller 提交于 
      The Page Deallocation Table (PDT) holds the physical addresses of all broken
memory addresses. With the physical address we now are able to show which DIMM
slot (e.g. 1a, 3c) actually holds the broken memory module so that users are
able to replace it.
Signed-off-by: NHelge Deller <deller@gmx.de>
      c46bafc4
    • H
      parisc: Add function to return DIMM slot of physical address · 25a9b765
      由 Helge Deller 提交于 
      Add a firmware wrapper function, which asks PDC firmware for the DIMM slot of a
physical address. This is needed to show users which DIMM module needs
replacement in case a broken DIMM was encountered.
Signed-off-by: NHelge Deller <deller@gmx.de>
      25a9b765
    • H
      parisc: Fix crash when calling PDC_PAT_MEM PDT firmware function · f520e552
      由 Helge Deller 提交于 
      Commit c9c2877d ("parisc: Add Page Deallocation Table (PDT) support")
introduced the pdc_pat_mem_read_pd_pdt() firmware helper function, which
crashed the system because it trashed the stack if the
pdc_pat_mem_read_pd_retinfo struct was located on the stack (and which is
in size less than the required 32 64-bit values).

Fix it by using the pdc_result struct instead when calling firmware and copy
the return values back into the result struct when finished sucessfully.

While debugging this code I noticed that the pdc_type wasn't set correctly
either, so let's fix that too.

Fixes: c9c2877d ("parisc: Add Page Deallocation Table (PDT) support")
Signed-off-by: NHelge Deller <deller@gmx.de>
      f520e552
  13. 25 7月, 2017 1 次提交
    • E
      signal: Remove kernel interal si_code magic · cc731525
      由 Eric W. Biederman 提交于 
      struct siginfo is a union and the kernel since 2.4 has been hiding a union
tag in the high 16bits of si_code using the values:
__SI_KILL
__SI_TIMER
__SI_POLL
__SI_FAULT
__SI_CHLD
__SI_RT
__SI_MESGQ
__SI_SYS

While this looks plausible on the surface, in practice this situation has
not worked well.

- Injected positive signals are not copied to user space properly
  unless they have these magic high bits set.

- Injected positive signals are not reported properly by signalfd
  unless they have these magic high bits set.

- These kernel internal values leaked to userspace via ptrace_peek_siginfo

- It was possible to inject these kernel internal values and cause the
  the kernel to misbehave.

- Kernel developers got confused and expected these kernel internal values
  in userspace in kernel self tests.

- Kernel developers got confused and set si_code to __SI_FAULT which
  is SI_USER in userspace which causes userspace to think an ordinary user
  sent the signal and that it was not kernel generated.

- The values make it impossible to reorganize the code to transform
  siginfo_copy_to_user into a plain copy_to_user.  As si_code must
  be massaged before being passed to userspace.

So remove these kernel internal si codes and make the kernel code simpler
and more maintainable.

To replace these kernel internal magic si_codes introduce the helper
function siginfo_layout, that takes a signal number and an si_code and
computes which union member of siginfo is being used.  Have
siginfo_layout return an enumeration so that gcc will have enough
information to warn if a switch statement does not handle all of union
members.

A couple of architectures have a messed up ABI that defines signal
specific duplications of SI_USER which causes more special cases in
siginfo_layout than I would like.  The good news is only problem
architectures pay the cost.

Update all of the code that used the previous magic __SI_ values to
use the new SIL_ values and to call siginfo_layout to get those
values.  Escept where not all of the cases are handled remove the
defaults in the switch statements so that if a new case is missed in
the future the lack will show up at compile time.

Modify the code that copies siginfo si_code to userspace to just copy
the value and not cast si_code to a short first.  The high bits are no
longer used to hold a magic union member.

Fixup the siginfo header files to stop including the __SI_ values in
their constants and for the headers that were missing it to properly
update the number of si_codes for each signal type.

The fixes to copy_siginfo_from_user32 implementations has the
interesting property that several of them perviously should never have
worked as the __SI_ values they depended up where kernel internal.
With that dependency gone those implementations should work much
better.

The idea of not passing the __SI_ values out to userspace and then
not reinserting them has been tested with criu and criu worked without
changes.

Ref: 2.4.0-test1
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      cc731525
  15. 24 7月, 2017 2 次提交
  17. 03 7月, 2017 1 次提交
  19. 29 6月, 2017 1 次提交
  21. 19 6月, 2017 1 次提交
    • H
      mm: larger stack guard gap, between vmas · 1be7107f
      由 Hugh Dickins 提交于 
      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: NOleg Nesterov <oleg@redhat.com>
Original-patch-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NHugh Dickins <hughd@google.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Tested-by: Helge Deller <deller@gmx.de> # parisc
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      1be7107f
  23. 09 6月, 2017 2 次提交
  25. 12 5月, 2017 1 次提交
    • H
      parisc: Add Page Deallocation Table (PDT) support · c9c2877d
      由 Helge Deller 提交于 
      The firmare in most parisc machines maintains a Page Deallocation Table (PDT)
which holds a list of physical memory addresses where hardware detected memory
errors (single bit and double bit errors).

This patch adds the missing PDC firmware calls and the logic to read the PDT
from firmware, report all current PDT entries and exclude the reported bad
memory from being used by Linux.
Signed-off-by: NHelge Deller <deller@gmx.de>
      c9c2877d
  27. 10 5月, 2017 2 次提交
  29. 09 5月, 2017 2 次提交
  31. 20 4月, 2017 2 次提交
  33. 30 3月, 2017 2 次提交
    • H
      parisc: Avoid stalled CPU warnings after system shutdown · 476e75a4
      由 Helge Deller 提交于 
      Commit 73580dac ("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: 73580dac ("parisc: Fix system shutdown halt")
Signed-off-by: NHelge Deller <deller@gmx.de>
Cc: stable@vger.kernel.org # 4.9+
      476e75a4
    • H
      parisc: Clean up fixup routines for get_user()/put_user() · d19f5e41
      由 Helge Deller 提交于 
      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: NAl Viro <viro@ZenIV.linux.org.uk>
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: NHelge Deller <deller@gmx.de>
      d19f5e41