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| author | Stephane Eranian <eranian@google.com> | 2012-06-11 15:44:26 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2012-06-13 15:00:28 +0200 |
| commit | 25f42985825dd93f0593efe454e54c2aa13f7830 (patch) | |
| tree | 1ceacad99b6bcd462c40ad6c32e4ed4751434595 | |
| parent | 9ee6ddc9dada9cc4b2201631bc74fbf203183a10 (diff) | |
| download | linux-25f42985825dd93f0593efe454e54c2aa13f7830.tar.gz linux-25f42985825dd93f0593efe454e54c2aa13f7830.tar.bz2 linux-25f42985825dd93f0593efe454e54c2aa13f7830.zip | |
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>
| -rw-r--r-- | arch/x86/lib/usercopy.c | 2 |
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 { |