Messages in this thread Patch in this message | | | Date | Mon, 12 Jan 2009 17:27:24 -0800 | From | Greg KH <> | Subject | [patch 16/21] parisc: disable UP-optimized flush_tlb_mm |
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2.6.27-stable review patch. If anyone has any objections, please let us know.
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From: Kyle McMartin <kyle@infradead.org>
commit 5289f46b9de04bde181d833d48df9671b69c4b08 upstream.
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@HansenPartnership.com> Tested-by: Helge Deller <deller@gmx.de> Signed-off-by: Kyle McMartin <kyle@mcmartin.ca> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- include/asm-parisc/tlbflush.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/include/asm-parisc/tlbflush.h +++ b/include/asm-parisc/tlbflush.h @@ -44,9 +44,12 @@ static inline void flush_tlb_mm(struct m { 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);
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