Commit Graph

14 Commits

Author SHA1 Message Date
Michael Neuling 2b3f8e87cf powerpc/tm: Fix userspace stack corruption on signal delivery for active transactions
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: Michael Neuling <mikey@neuling.org>
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-06-01 08:29:23 +10:00
Michael Neuling 2b0a576d15 powerpc: Add new transactional memory state to the signal context
This adds the new transactional memory archtected state to the signal context
in both 32 and 64 bit.

Signed-off-by: Matt Evans <matt@ozlabs.org>
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2013-02-15 17:02:23 +11:00
Al Viro 17440f171e powerpc: get rid of restore_sigmask()
... it's just a call of set_current_blocked() now

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:51 -04:00
Al Viro 77097ae503 most of set_current_blocked() callers want SIGKILL/SIGSTOP removed from set
Only 3 out of 63 do not.  Renamed the current variant to __set_current_blocked(),
added set_current_blocked() that will exclude unblockable signals, switched
open-coded instances to it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-01 12:58:51 -04:00
Benjamin Herrenschmidt 18b246fa60 powerpc: Fix various issues with return to userspace
We have a few problems when returning to userspace. This is a
quick set of fixes for 3.3, I'll look into a more comprehensive
rework for 3.4. This fixes:

 - We kept interrupts soft-disabled when schedule'ing or calling
do_signal when returning to userspace as a result of a hardware
interrupt.

 - Rename do_signal to do_notify_resume like all other archs (and
do_signal_pending back to do_signal, which it was before Roland
changed it).

 - Add the missing call to key_replace_session_keyring() to
do_notify_resume().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
---
2012-02-22 16:48:53 +11:00
Josh Boyer efbda86098 powerpc: Sanitize stack pointer in signal handling code
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: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-27 16:58:24 +11:00
Anton Blanchard a465f9b694 powerpc: Move is_32bit_task
Move is_32bit_task into asm/thread_info.h, that allows us to test for
32/64bit tasks without an ugly CONFIG_PPC64 ifdef.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-02-23 15:53:06 +11:00
Al Viro 2e074004c6 x86, um: get rid of uml signal.h
the only theoretical reason for it these days is ppc; aside of uml/ppc
being dead, do_signal() would be happier in arch/powerpc/kernel/signal.h
anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
2008-10-22 22:55:20 -07:00
Michael Neuling 6a274c08f2 powerpc: Clean up copy_to/from_user for vsx and fpr
This merges and cleans up some of the ugly copy/to from user code
which is required for the new fpr and vsx layout in the thread_struct.

Also fixes some hard coded buffer sizes and removes a redundant
fpr_flush_to_thread.

Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2008-07-03 16:58:11 +10:00
Benjamin Herrenschmidt 2f97cd3912 [POWERPC] Less ifdef's in signal.c/signal.h
This patch moves things around a little bit in the new common signal.c
and signal.h files to remove the last #ifdef in the middle of the
common do_signal().

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:58 +10:00
Benjamin Herrenschmidt a3f61dc0a5 [POWERPC] Merge creation of signal frame
The code for creating signal frames was still duplicated and split
in strange ways between 32 and 64 bits, including the SA_ONSTACK
handling being in do_signal on 32 bits but inside handle_rt_signal
on 64 bits etc...

This moves the 64 bits get_sigframe() to the generic signal.c,
cleans it a bit, moves the access_ok() call done by all callers to
it as well, and adapts/cleanups the 3 different signal handling cases
to use that common function.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:58 +10:00
Christoph Hellwig f478f5430c [POWERPC] Consolidate do_signal
do_signal has exactly the same behaviour on 32bit and 64bit and 32bit
compat on 64bit for handling 32bit signals.  Consolidate all these
into one common function in signal.c.  The only odd left over is
the try_to_free in the 32bit version that no other architecture has
in mainline (only in i386 for some odd SuSE release).  We should
probably get rid of it in a separate patch.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:58 +10:00
Christoph Hellwig db277e9a67 [POWERPC] Consolidate restore_sigmask
restore_sigmask is exactly the same on 32 and 64bit, so move it to
common code.  Also move _BLOCKABLE to signal.h to avoid defining it
multiple times.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:58 +10:00
Benjamin Herrenschmidt 22e38f2932 [POWERPC] Make syscall restart code more common
This patch moves the code in signal_32.c and signal_64.c for handling
syscall restart into a common signal.c file and converge around a single
implementation that is based on the 32 bits one, using trap, ccr
and r3 rather than the special "result" field for deciding what to do.

The "result" field is now pretty much deprecated. We still set it for
the sake of whatever might rely on it in userland but we no longer use
it's content.

This, along with a previous patch that enables ptracers to write to
"trap" and "orig_r3" should allow gdb to properly handle syscall
restarting.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
2007-06-14 22:29:57 +10:00