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authorIngo Molnar <mingo@elte.hu>2009-09-15 12:18:15 +0200
committerIngo Molnar <mingo@elte.hu>2009-09-15 12:18:15 +0200
commitdca2d6ac09d9ef59ff46820d4f0c94b08a671202 (patch)
treefdec753b842dad09e3a4151954fab3eb5c43500d /arch/powerpc/mm/stab.c
parentd6a65dffb30d8636b1e5d4c201564ef401a246cf (diff)
parent18240904960a39e582ced8ba8ececb10b8c22dd3 (diff)
downloadlinux-next-dca2d6ac09d9ef59ff46820d4f0c94b08a671202.tar.gz
linux-next-dca2d6ac09d9ef59ff46820d4f0c94b08a671202.zip
Merge branch 'linus' into tracing/hw-breakpoints
Conflicts: arch/x86/kernel/process_64.c Semantic conflict fixed in: arch/x86/kvm/x86.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/powerpc/mm/stab.c')
-rw-r--r--arch/powerpc/mm/stab.c11
1 files changed, 10 insertions, 1 deletions
diff --git a/arch/powerpc/mm/stab.c b/arch/powerpc/mm/stab.c
index 98cd1dc2ae75..ab5fb48b3e90 100644
--- a/arch/powerpc/mm/stab.c
+++ b/arch/powerpc/mm/stab.c
@@ -164,7 +164,7 @@ void switch_stab(struct task_struct *tsk, struct mm_struct *mm)
{
struct stab_entry *stab = (struct stab_entry *) get_paca()->stab_addr;
struct stab_entry *ste;
- unsigned long offset = __get_cpu_var(stab_cache_ptr);
+ unsigned long offset;
unsigned long pc = KSTK_EIP(tsk);
unsigned long stack = KSTK_ESP(tsk);
unsigned long unmapped_base;
@@ -172,6 +172,15 @@ void switch_stab(struct task_struct *tsk, struct mm_struct *mm)
/* Force previous translations to complete. DRENG */
asm volatile("isync" : : : "memory");
+ /*
+ * We need interrupts hard-disabled here, not just soft-disabled,
+ * so that a PMU interrupt can't occur, which might try to access
+ * user memory (to get a stack trace) and possible cause an STAB miss
+ * which would update the stab_cache/stab_cache_ptr per-cpu variables.
+ */
+ hard_irq_disable();
+
+ offset = __get_cpu_var(stab_cache_ptr);
if (offset <= NR_STAB_CACHE_ENTRIES) {
int i;