trace: add build-time check to avoid overrunning hex buffer
Remove the runtime BUG_ON and change to a compile-time check in
the macro that calls the hex format routine
[Noticed by Joe Perches]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 36cbb87..d345d64 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -335,7 +335,8 @@
return len;
}
-#define HEX_CHARS 17
+#define MAX_MEMHEX_BYTES 8
+#define HEX_CHARS (MAX_MEMHEX_BYTES*2 + 1)
static int
trace_seq_putmem_hex(struct trace_seq *s, void *mem, size_t len)
@@ -344,8 +345,6 @@
unsigned char *data = mem;
int i, j;
- BUG_ON(len >= HEX_CHARS);
-
#ifdef __BIG_ENDIAN
for (i = 0, j = 0; i < len; i++) {
#else
@@ -1668,6 +1667,7 @@
#define SEQ_PUT_HEX_FIELD_RET(s, x) \
do { \
+ BUILD_BUG_ON(sizeof(x) > MAX_MEMHEX_BYTES); \
if (!trace_seq_putmem_hex(s, &(x), sizeof(x))) \
return 0; \
} while (0)