The cppcheck static code analysis reported the following error:
>> helpers.c:713:43: warning: Uninitialized variable: bufs [uninitvar]
if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bufs->tmp_bufs))) {
^
ARRAY_SIZE is a macro that expands to sizeofs, so bufs is not actually
dereferenced at runtime, and the code is actually safe. But to keep
things tidy, this patch removes the need for a call to ARRAY_SIZE by
extracting the size of the array into a macro. Cppcheck should no longer
be confused and the code ends up being a bit cleaner.
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Florent Revest <revest@xxxxxxxxxxxx>
---
kernel/bpf/helpers.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index 3a5ab614cbb0..73443498d88f 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -698,8 +698,9 @@ static int bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype,
#define MAX_BPRINTF_BUF_LEN 512
/* Support executing three nested bprintf helper calls on a given CPU */
+#define MAX_BPRINTF_NEST_LEVEL 3
struct bpf_bprintf_buffers {
- char tmp_bufs[3][MAX_BPRINTF_BUF_LEN];
+ char tmp_bufs[MAX_BPRINTF_NEST_LEVEL][MAX_BPRINTF_BUF_LEN];
};
static DEFINE_PER_CPU(struct bpf_bprintf_buffers, bpf_bprintf_bufs);
static DEFINE_PER_CPU(int, bpf_bprintf_nest_level);
@@ -711,7 +712,7 @@ static int try_get_fmt_tmp_buf(char **tmp_buf)
preempt_disable();
nest_level = this_cpu_inc_return(bpf_bprintf_nest_level);
- if (WARN_ON_ONCE(nest_level > ARRAY_SIZE(bufs->tmp_bufs))) {
+ if (WARN_ON_ONCE(nest_level > MAX_BPRINTF_NEST_LEVEL)) {
this_cpu_dec(bpf_bprintf_nest_level);
preempt_enable();
return -EBUSY;
--
2.31.1.751.gd2f1c929bd-goog
