OpenCloudOS-Kernel/arch/powerpc
Paul Mackerras ae62fbb5f1 [POWERPC] Fix subtle FP state corruption bug in signal return on SMP
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: Paul Mackerras <paulus@samba.org>
2007-06-26 14:49:11 +10:00
..
boot [POWERPC] Fix building of COFF zImages 2007-06-07 22:21:31 +10:00
configs [POWERPC] Update defconfigs 2007-06-26 14:38:47 +10:00
kernel [POWERPC] Fix subtle FP state corruption bug in signal return on SMP 2007-06-26 14:49:11 +10:00
lib [POWERPC] rheap - eliminates internal fragments caused by alignment 2007-06-19 22:35:53 -05:00
math-emu [POWERPC] ppc math-emu needs -fno-builtin-fabs for math.c and fabs.c 2006-09-26 15:24:35 +10:00
mm [POWERPC] PowerPC: Prevent data exception in kernel space (32-bit) 2007-06-20 22:07:38 +10:00
oprofile Fix misspellings collected by members of KJ list. 2007-05-09 07:14:03 +02:00
platforms [POWERPC] Fix powermac late initcall to only run on powermac 2007-06-20 22:07:38 +10:00
sysdev [POWERPC] QE: fix Kconfig 'select' warning with UCC_FAST 2007-05-23 07:23:55 -05:00
xmon Simplify kallsyms_lookup() 2007-05-08 11:15:08 -07:00
.gitignore [POWERPC] Add files build to .gitignore 2006-12-04 20:41:29 +11:00
Kconfig [POWERPC] Fix Kconfig warning 2007-05-23 09:51:46 -05:00
Kconfig.debug Fix trivial typos in Kconfig* files 2007-05-09 07:12:20 +02:00
Makefile [POWERPC] Create a zImage for legacy iSeries 2007-06-02 21:01:56 +10:00