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| author |   Oliver O'Halloran <oohall@gmail.com> | 2016-03-08 09:08:47 +1100 |
|---|---|---|
| committer |   Michael Ellerman <mpe@ellerman.id.au> | 2016-03-29 12:08:08 +1100 |
| commit | 01d7c2a2de47890934faba91a71d183795e4348d (patch) | |
| tree | 92b4a3070ef4156cccb042d20144952c4b552497 /arch | |
| parent | powerpc/mm: Fixup preempt underflow with huge pages (diff) | |
| download | linux-dev-01d7c2a2de47890934faba91a71d183795e4348d.tar.xz linux-dev-01d7c2a2de47890934faba91a71d183795e4348d.zip | |
powerpc/process: Fix altivec SPR not being saved
In save_sprs() in process.c contains the following test:
if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC)))
t->vrsave = mfspr(SPRN_VRSAVE);
CPU feature with the mask 0x1 is CPU_FTR_COHERENT_ICACHE so the test
is equivilent to:
if (cpu_has_feature(CPU_FTR_ALTIVEC) &&
cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
On CPUs without support for both (i.e G5) this results in vrsave not
being saved between context switches. The vector register save/restore
code doesn't use VRSAVE to determine which registers to save/restore,
but the value of VRSAVE is used to determine if altivec is being used
in several code paths.
Fixes: 152d523e6307 ("powerpc: Create context switch helpers save_sprs() and restore_sprs()")
Cc: stable@vger.kernel.org
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/powerpc/kernel/process.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c index 612df305886b..b8500b4ac7fe 100644 --- a/arch/powerpc/kernel/process.c +++ b/arch/powerpc/kernel/process.c @@ -983,7 +983,7 @@ void restore_tm_state(struct pt_regs *regs) static inline void save_sprs(struct thread_struct *t) { #ifdef CONFIG_ALTIVEC - if (cpu_has_feature(cpu_has_feature(CPU_FTR_ALTIVEC))) + if (cpu_has_feature(CPU_FTR_ALTIVEC)) t->vrsave = mfspr(SPRN_VRSAVE); #endif #ifdef CONFIG_PPC_BOOK3S_64 |