flush_tlb_mm's "optimized" uniprocessor case of allocating a new context for userspace is exposing a race where we can suddely return to a syscall with the protection id and space id out of sync, trapping on the next userspace access. Debugged-by: James Bottomley <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> Tested-by: Helge Deller <deller@xxxxxx> Signed-off-by: Kyle McMartin <kyle@xxxxxxxxxxx> --- Linus, Greg, please apply to stable and HEAD, this is a fairly important fix for parisc. Thanks, Kyle arch/parisc/include/asm/tlbflush.h | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/arch/parisc/include/asm/tlbflush.h b/arch/parisc/include/asm/tlbflush.h index b72ec66..1f6fd4f 100644 --- a/arch/parisc/include/asm/tlbflush.h +++ b/arch/parisc/include/asm/tlbflush.h @@ -44,9 +44,12 @@ static inline void flush_tlb_mm(struct mm_struct *mm) { BUG_ON(mm == &init_mm); /* Should never happen */ -#ifdef CONFIG_SMP +#if 1 || defined(CONFIG_SMP) flush_tlb_all(); #else + /* FIXME: currently broken, causing space id and protection ids + * to go out of sync, resulting in faults on userspace accesses. + */ if (mm) { if (mm->context != 0) free_sid(mm->context); -- 1.6.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-parisc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html