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authorSteven Rostedt (VMware) <[email protected]>2019-12-11 20:44:22 +0000
committerSteven Rostedt (VMware) <[email protected]>2019-12-19 23:26:00 +0000
commit106f41f5a302cb1f36c7543fae6a05de12e96fa4 (patch)
treec3b4c17919575dd2ad393048409cb142ce435115
parenttracing: Avoid memory leak in process_system_preds() (diff)
downloadkernel-106f41f5a302cb1f36c7543fae6a05de12e96fa4.tar.gz
kernel-106f41f5a302cb1f36c7543fae6a05de12e96fa4.zip
tracing: Have the histogram compare functions convert to u64 first
The compare functions of the histogram code would be specific for the size of the value being compared (byte, short, int, long long). It would reference the value from the array via the type of the compare, but the value was stored in a 64 bit number. This is fine for little endian machines, but for big endian machines, it would end up comparing zeros or all ones (depending on the sign) for anything but 64 bit numbers. To fix this, first derference the value as a u64 then convert it to the type being compared. Link: http://lkml.kernel.org/r/[email protected] Cc: [email protected] Fixes: 08d43a5fa063e ("tracing: Add lock-free tracing_map") Acked-by: Tom Zanussi <[email protected]> Reported-by: Sven Schnelle <[email protected]> Signed-off-by: Steven Rostedt (VMware) <[email protected]>
-rw-r--r--kernel/trace/tracing_map.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c
index 9a1c22310323..9e31bfc818ff 100644
--- a/kernel/trace/tracing_map.c
+++ b/kernel/trace/tracing_map.c
@@ -148,8 +148,8 @@ static int tracing_map_cmp_atomic64(void *val_a, void *val_b)
#define DEFINE_TRACING_MAP_CMP_FN(type) \
static int tracing_map_cmp_##type(void *val_a, void *val_b) \
{ \
- type a = *(type *)val_a; \
- type b = *(type *)val_b; \
+ type a = (type)(*(u64 *)val_a); \
+ type b = (type)(*(u64 *)val_b); \
\
return (a > b) ? 1 : ((a < b) ? -1 : 0); \
}