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authorStephane Eranian <eranian@google.com>2012-06-11 15:44:26 +0200
committerIngo Molnar <mingo@kernel.org>2012-06-13 15:00:28 +0200
commit25f42985825dd93f0593efe454e54c2aa13f7830 (patch)
tree1ceacad99b6bcd462c40ad6c32e4ed4751434595 /arch/x86/lib/usercopy.c
parent9ee6ddc9dada9cc4b2201631bc74fbf203183a10 (diff)
downloadlinux-25f42985825dd93f0593efe454e54c2aa13f7830.tar.bz2
perf/x86: Fix broken LBR fixup code
I noticed that the LBR fixups were not working anymore on programs where they used to. I tracked this down to a recent change to copy_from_user_nmi(): db0dc75d640 ("perf/x86: Check user address explicitly in copy_from_user_nmi()") This commit added a call to __range_not_ok() to the copy_from_user_nmi() routine. The problem is that the logic of the test must be reversed. __range_not_ok() returns 0 if the range is VALID. We want to return early from copy_from_user_nmi() if the range is NOT valid. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Arun Sharma <asharma@fb.com> Link: http://lkml.kernel.org/r/20120611134426.GA7542@quad Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/lib/usercopy.c')
-rw-r--r--arch/x86/lib/usercopy.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/lib/usercopy.c b/arch/x86/lib/usercopy.c
index 677b1ed184c9..4f74d94c8d97 100644
--- a/arch/x86/lib/usercopy.c
+++ b/arch/x86/lib/usercopy.c
@@ -22,7 +22,7 @@ copy_from_user_nmi(void *to, const void __user *from, unsigned long n)
void *map;
int ret;
- if (__range_not_ok(from, n, TASK_SIZE) == 0)
+ if (__range_not_ok(from, n, TASK_SIZE))
return len;
do {