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  1. 01 6月, 2013 1 次提交
    • M
      powerpc/tm: Fix userspace stack corruption on signal delivery for active transactions · 2b3f8e87
      由 Michael Neuling 提交于 
      When in an active transaction that takes a signal, we need to be careful with
the stack.  It's possible that the stack has moved back up after the tbegin.
The obvious case here is when the tbegin is called inside a function that
returns before a tend.  In this case, the stack is part of the checkpointed
transactional memory state.  If we write over this non transactionally or in
suspend, we are in trouble because if we get a tm abort, the program counter
and stack pointer will be back at the tbegin but our in memory stack won't be
valid anymore.

To avoid this, when taking a signal in an active transaction, we need to use
the stack pointer from the checkpointed state, rather than the speculated
state.  This ensures that the signal context (written tm suspended) will be
written below the stack required for the rollback.  The transaction is aborted
becuase of the treclaim, so any memory written between the tbegin and the
signal will be rolled back anyway.

For signals taken in non-TM or suspended mode, we use the
normal/non-checkpointed stack pointer.

Tested with 64 and 32 bit signals
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      2b3f8e87
  3. 10 4月, 2013 1 次提交
  5. 15 2月, 2013 1 次提交
  7. 04 2月, 2013 1 次提交
  9. 19 11月, 2012 1 次提交
  11. 02 6月, 2012 1 次提交
  13. 29 3月, 2012 1 次提交
  15. 01 11月, 2011 1 次提交
  17. 29 6月, 2011 1 次提交
  19. 27 4月, 2011 1 次提交
  21. 23 9月, 2010 1 次提交
  23. 27 3月, 2009 1 次提交
    • J
      powerpc: Sanitize stack pointer in signal handling code · efbda860
      由 Josh Boyer 提交于 
      On powerpc64 machines running 32-bit userspace, we can get garbage bits in the
stack pointer passed into the kernel.  Most places handle this correctly, but
the signal handling code uses the passed value directly for allocating signal
stack frames.

This fixes the issue by introducing a get_clean_sp function that returns a
sanitized stack pointer.  For 32-bit tasks on a 64-bit kernel, the stack
pointer is masked correctly.  In all other cases, the stack pointer is simply
returned.

Additionally, we pass an 'is_32' parameter to get_sigframe now in order to
get the properly sanitized stack.  The callers are know to be 32 or 64-bit
statically.
Signed-off-by: NJosh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
      efbda860
  25. 31 10月, 2008 1 次提交
    • M
      powerpc: Fix swapcontext system for VSX + old ucontext size · 16c29d18
      由 Michael Neuling 提交于 
      Since VSX support was added, we now have two sizes of ucontext_t;
the older, smaller size without the extra VSX state, and the new
larger size with the extra VSX state.  A program using the
sys_swapcontext system call and supplying smaller ucontext_t
structures will currently get an EINVAL error if the task has
used VSX (e.g. because of calling library code that uses VSX) and
the old_ctx argument is non-NULL (i.e. the program is asking for
its current context to be saved).  Thus the program will start
getting EINVAL errors on calls that previously worked.

This commit changes this behaviour so that we don't send an EINVAL in
this case.  It will now return the smaller context but the VSX MSR bit
will always be cleared to indicate that the ucontext_t doesn't include
the extra VSX state, even if the task has executed VSX instructions.

Both 32 and 64 bit cases are updated.

[paulus@samba.org - also fix some access_ok() and get_user() calls]

Thanks to Ben Herrenschmidt for noticing this problem.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      16c29d18
  27. 22 10月, 2008 1 次提交
  29. 15 7月, 2008 1 次提交
  31. 09 7月, 2008 1 次提交
  33. 03 7月, 2008 1 次提交
  35. 01 7月, 2008 4 次提交
    • M
      powerpc: Fix compile error for CONFIG_VSX · 436db693
      由 Michael Neuling 提交于 
      Fix compile error when CONFIG_VSX is enabled.

arch/powerpc/kernel/signal_64.c: In function 'restore_sigcontext':
arch/powerpc/kernel/signal_64.c:241: error: 'i' undeclared (first use in this function)
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      436db693
    • S
      powerpc: Explicitly copy elements of pt_regs · fcbc5a97
      由 Stephen Rothwell 提交于 
      Gcc 4.3 produced this warning:

arch/powerpc/kernel/signal_64.c: In function 'restore_sigcontext':
arch/powerpc/kernel/signal_64.c:161: warning: array subscript is above array bounds

This is caused by us copying to aliases of elements of the pt_regs
structure.  Make those explicit.

This adds one extra __get_user and unrolls a loop.
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      fcbc5a97
    • M
      powerpc: Add VSX context save/restore, ptrace and signal support · ce48b210
      由 Michael Neuling 提交于 
      This patch extends the floating point save and restore code to use the
VSX load/stores when VSX is available.  This will make FP context
save/restore marginally slower on FP only code, when VSX is available,
as it has to load/store 128bits rather than just 64bits.

Mixing FP, VMX and VSX code will get constant architected state.

The signals interface is extended to enable access to VSR 0-31
doubleword 1 after discussions with tool chain maintainers.  Backward
compatibility is maintained.

The ptrace interface is also extended to allow access to VSR 0-31 full
registers.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      ce48b210
    • M
      powerpc: Introduce VSX thread_struct and CONFIG_VSX · c6e6771b
      由 Michael Neuling 提交于 
      The layout of the new VSR registers and how they overlap on top of the
legacy FPR and VR registers is:

                   VSR doubleword 0               VSR doubleword 1
          ----------------------------------------------------------------
  VSR[0]  |             FPR[0]            |                              |
          ----------------------------------------------------------------
  VSR[1]  |             FPR[1]            |                              |
          ----------------------------------------------------------------
          |              ...              |                              |
          |              ...              |                              |
          ----------------------------------------------------------------
  VSR[30] |             FPR[30]           |                              |
          ----------------------------------------------------------------
  VSR[31] |             FPR[31]           |                              |
          ----------------------------------------------------------------
  VSR[32] |                             VR[0]                            |
          ----------------------------------------------------------------
  VSR[33] |                             VR[1]                            |
          ----------------------------------------------------------------
          |                              ...                             |
          |                              ...                             |
          ----------------------------------------------------------------
  VSR[62] |                             VR[30]                           |
          ----------------------------------------------------------------
  VSR[63] |                             VR[31]                           |
          ----------------------------------------------------------------

VSX has 64 128bit registers.  The first 32 regs overlap with the FP
registers and hence extend them with and additional 64 bits.  The
second 32 regs overlap with the VMX registers.

This commit introduces the thread_struct changes required to reflect
this register layout.  Ptrace and signals code is updated so that the
floating point registers are correctly accessed from the thread_struct
when CONFIG_VSX is enabled.
Signed-off-by: NMichael Neuling <mikey@neuling.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      c6e6771b
  37. 09 6月, 2008 1 次提交
  39. 12 10月, 2007 1 次提交
  41. 26 6月, 2007 1 次提交
    • P
      [POWERPC] Fix subtle FP state corruption bug in signal return on SMP · ae62fbb5
      由 Paul Mackerras 提交于 
      This fixes a bug which can cause corruption of the floating-point state
on return from a signal handler.  If we have a signal handler that has
used the floating-point registers, and it happens to context-switch to
another task while copying the interrupted floating-point state from the
user stack into the thread struct (e.g. because of a page fault, or
because it gets preempted), the context switch code will think that the
FP registers contain valid FP state that needs to be copied into the
thread_struct, and will thus overwrite the values that the signal return
code has put into the thread_struct.

This can occur because we clear the MSR bits that indicate the presence
of valid FP state after copying the state into the thread_struct.  To fix
this we just move the clearing of the MSR bits to before the copy.  A
similar potential problem also occurs with the Altivec state, and this
fixes that in the same way.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      ae62fbb5
  43. 14 6月, 2007 5 次提交
  45. 09 5月, 2007 1 次提交
  47. 01 7月, 2006 1 次提交
  49. 09 6月, 2006 3 次提交
    • P
      [PATCH] powerpc: Implement support for setting little-endian mode via prctl · fab5db97
      由 Paul Mackerras 提交于 
      This adds the PowerPC part of the code to allow processes to change
their endian mode via prctl.

This also extends the alignment exception handler to be able to fix up
alignment exceptions that occur in little-endian mode, both for
"PowerPC" little-endian and true little-endian.

We always enter signal handlers in big-endian mode -- the support for
little-endian mode does not amount to the creation of a little-endian
user/kernel ABI.  If the signal handler returns, the endian mode is
restored to what it was when the signal was delivered.

We have two new kernel CPU feature bits, one for PPC little-endian and
one for true little-endian.  Most of the classic 32-bit processors
support PPC little-endian, and this is reflected in the CPU feature
table.  There are two corresponding feature bits reported to userland
in the AT_HWCAP aux vector entry.

This is based on an earlier patch by Anton Blanchard.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      fab5db97
    • B
      [PATCH] powerpc vdso updates · a5bba930
      由 Benjamin Herrenschmidt 提交于 
      This patch cleans up some locking & error handling in the ppc vdso and
moves the vdso base pointer from the thread struct to the mm context
where it more logically belongs. It brings the powerpc implementation
closer to Ingo's new x86 one and also adds an arch_vma_name() function
allowing to print [vsdo] in /proc/<pid>/maps if Ingo's x86 vdso patch is
also applied.
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      a5bba930
    • P
      powerpc: Fix machine check problem on 32-bit kernels · 7c85d1f9
      由 Paul Mackerras 提交于 
      This fixes a bug found by Dave Jones that means that it is possible
for userspace to provoke a machine check on 32-bit kernels.  This
also fixes a couple of other places where I found similar problems
by inspection.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      7c85d1f9
  51. 28 3月, 2006 1 次提交
    • L
      [PATCH] powerpc: fix incorrect SA_ONSTACK behaviour for 64-bit processes · 11089f08
      由 Laurent MEYER 提交于 
      *) When setting a sighandler using sigaction() call, if the flag
SA_ONSTACK is set and no alternate stack is provided via sigaltstack(),
the kernel still try to install the alternate stack. This behavior is
the opposite of the one which is documented in Single Unix
Specifications V3.

*) Also when setting an alternate stack using sigaltstack() with the
flag SS_DISABLE, the kernel try to install the alternate stack on
signal delivery.

These two use cases makes the process crash at signal delivery.

This fixes it.
Signed-off-by: NLaurent Meyer <meyerlau@fr.ibm.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      11089f08
  53. 27 3月, 2006 1 次提交
  55. 08 3月, 2006 1 次提交
    • P
      powerpc: Fix various syscall/signal/swapcontext bugs · 1bd79336
      由 Paul Mackerras 提交于 
      A careful reading of the recent changes to the system call entry/exit
paths revealed several problems, plus some things that could be
simplified and improved:

* 32-bit wasn't testing the _TIF_NOERROR bit in the syscall fast exit
  path, so it was only doing anything with it once it saw some other
  bit being set.  In other words, the noerror behaviour would apply to
  the next system call where we had to reschedule or deliver a signal,
  which is not necessarily the current system call.

* 32-bit wasn't doing the call to ptrace_notify in the syscall exit
  path when the _TIF_SINGLESTEP bit was set.

* _TIF_RESTOREALL was in both _TIF_USER_WORK_MASK and
  _TIF_PERSYSCALL_MASK, which is odd since _TIF_RESTOREALL is only set
  by system calls.  I took it out of _TIF_USER_WORK_MASK.

* On 64-bit, _TIF_RESTOREALL wasn't causing the non-volatile registers
  to be restored (unless perhaps a signal was delivered or the syscall
  was traced or single-stepped).  Thus the non-volatile registers
  weren't restored on exit from a signal handler.  We probably got
  away with it mostly because signal handlers written in C wouldn't
  alter the non-volatile registers.

* On 32-bit I simplified the code and made it more like 64-bit by
  making the syscall exit path jump to ret_from_except to handle
  preemption and signal delivery.

* 32-bit was calling do_signal unnecessarily when _TIF_RESTOREALL was
  set - but I think because of that 32-bit was actually restoring the
  non-volatile registers on exit from a signal handler.

* I changed the order of enabling interrupts and saving the
  non-volatile registers before calling do_syscall_trace_leave; now we
  enable interrupts first.
Signed-off-by: NPaul Mackerras <paulus@samba.org>
      1bd79336
  57. 10 2月, 2006 1 次提交
  59. 08 2月, 2006 1 次提交
  61. 19 1月, 2006 1 次提交