2.6.32-longterm review patch. If anyone has any objections, please let me know.
------------------ From: Junxiao Bi <[email protected]> If one kernel path is using KM_USER0 slot and is interrupted by the oprofile nmi, then in copy_from_user_nmi(), the KM_USER0 slot will be overwrite and cleared to zero at last, when the control return to the original kernel path, it will access an invalid virtual address and trigger a crash. Cc: Robert Richter <[email protected]> Cc: Greg KH <[email protected]> Cc: [email protected] Signed-off-by: Junxiao Bi <[email protected]> [WT: According to Junxiao and Robert, this patch is needed for stable kernels which include a backport of a0e3e70243f5b270bc3eca718f0a9fa5e6b8262e without 3e4d3af501cccdc8a8cca41bdbe57d54ad7e7e73, but there is no exact equivalent in mainline] Signed-off-by: Willy Tarreau <[email protected]> --- arch/x86/oprofile/backtrace.c | 4 ++-- 1 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/x86/oprofile/backtrace.c b/arch/x86/oprofile/backtrace.c index 829edf0..b50a280 100644 --- a/arch/x86/oprofile/backtrace.c +++ b/arch/x86/oprofile/backtrace.c @@ -71,9 +71,9 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n) offset = addr & (PAGE_SIZE - 1); size = min(PAGE_SIZE - offset, n - len); - map = kmap_atomic(page, KM_USER0); + map = kmap_atomic(page, KM_NMI); memcpy(to, map+offset, size); - kunmap_atomic(map, KM_USER0); + kunmap_atomic(map, KM_NMI); put_page(page); len += size; -- 1.7.2.1.45.g54fbc -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
