[PATCH AUTOSEL for 4.4 086/101] powerpc/perf/hv-24x7: Fix incorrect comparison in memord

From: alexander . levin
Date: Thu Dec 07 2017 - 11:33:09 EST


From: Michael Ellerman <mpe@xxxxxxxxxxxxxx>

[ Upstream commit 05c14c03138532a3cb2aa29c2960445c8753343b ]

In the hv-24x7 code there is a function memord() which tries to
implement a sort function return -1, 0, 1. However one of the
conditions is incorrect, such that it can never be true, because we
will have already returned.

I don't believe there is a bug in practice though, because the
comparisons are an optimisation prior to calling memcmp().

Fix it by swapping the second comparision, so it can be true.

Reported-by: David Binderman <dcb314@xxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxx>
---
arch/powerpc/perf/hv-24x7.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/perf/hv-24x7.c b/arch/powerpc/perf/hv-24x7.c
index 9f9dfda9ed2c..e8ca0fad2e69 100644
--- a/arch/powerpc/perf/hv-24x7.c
+++ b/arch/powerpc/perf/hv-24x7.c
@@ -514,7 +514,7 @@ static int memord(const void *d1, size_t s1, const void *d2, size_t s2)
{
if (s1 < s2)
return 1;
- if (s2 > s1)
+ if (s1 > s2)
return -1;

return memcmp(d1, d2, s1);
--
2.11.0