diff options
| author | Michael Neuling <mikey@neuling.org> | 2013-12-16 15:12:43 +1100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-01-08 09:42:11 -0800 |
| commit | 4e6cc83041aacf32013022d922c34230ee6e6e90 (patch) | |
| tree | ddccdec6b806662e471834a8b2c8f7e6835f4b7c /tools/lguest | |
| parent | 7110adb76087508116e4ce1496b8ca7a57e2d85d (diff) | |
powerpc: Fix bad stack check in exception entry
commit 90ff5d688e61f49f23545ffab6228bd7e87e6dc7 upstream.
In EXCEPTION_PROLOG_COMMON() we check to see if the stack pointer (r1)
is valid when coming from the kernel. If it's not valid, we die but
with a nice oops message.
Currently we allocate a stack frame (subtract INT_FRAME_SIZE) before we
check to see if the stack pointer is negative. Unfortunately, this
won't detect a bad stack where r1 is less than INT_FRAME_SIZE.
This patch fixes the check to compare the modified r1 with
-INT_FRAME_SIZE. With this, bad kernel stack pointers (including NULL
pointers) are correctly detected again.
Kudos to Paulus for finding this.
Signed-off-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'tools/lguest')
0 files changed, 0 insertions, 0 deletions