| Message ID | 20210517092830.1026418-2-revest@chromium.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d0c0fe10ce6d87734b65c18dc8f4bcae3f4dbea4 |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf,1/2] bpf: Clarify a bpf_bprintf_prepare macro | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | fail | Series targets non-next tree, but doesn't contain any Fixes tags |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Clearly marked for bpf |
| netdev/subject_prefix | success | Link |
| netdev/cc_maintainers | warning | 5 maintainers not CCed: netdev@vger.kernel.org yhs@fb.com kafai@fb.com john.fastabend@gmail.com songliubraving@fb.com |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 6 this patch: 6 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 18 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 6 this patch: 6 |
| netdev/header_inline | success | Link |
On Mon, May 17, 2021 at 2:29 AM Florent Revest <revest@chromium.org> wrote: > > 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@intel.com> > Signed-off-by: Florent Revest <revest@chromium.org> Acked-by: Song Liu <song@kernel.org> > --- > 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 >
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;