| Message ID | 20230724201247.748146-3-irogers@google.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Delegated to: | BPF |
| Headers | show |
| Series | Perf tool LTO support | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch |
| bpf/vmtest-bpf-next-PR | success | PR summary |
| bpf/vmtest-bpf-next-VM_Test-1 | success | Logs for ShellCheck |
| bpf/vmtest-bpf-next-VM_Test-6 | success | Logs for set-matrix |
| bpf/vmtest-bpf-next-VM_Test-2 | success | Logs for build for aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-4 | success | Logs for build for x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-5 | success | Logs for build for x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-3 | success | Logs for build for s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-10 | success | Logs for test_maps on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-20 | success | Logs for test_progs_no_alu32_parallel on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-21 | success | Logs for test_progs_no_alu32_parallel on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-24 | success | Logs for test_progs_parallel on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-25 | success | Logs for test_verifier on aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-27 | success | Logs for test_verifier on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-28 | success | Logs for test_verifier on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-29 | success | Logs for veristat |
| bpf/vmtest-bpf-next-VM_Test-7 | success | Logs for test_maps on aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-9 | success | Logs for test_maps on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-11 | success | Logs for test_progs on aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-13 | success | Logs for test_progs on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-14 | success | Logs for test_progs on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-15 | success | Logs for test_progs_no_alu32 on aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-17 | success | Logs for test_progs_no_alu32 on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-18 | success | Logs for test_progs_no_alu32 on x86_64 with llvm-16 |
| bpf/vmtest-bpf-next-VM_Test-19 | success | Logs for test_progs_no_alu32_parallel on aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-22 | success | Logs for test_progs_parallel on aarch64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-23 | success | Logs for test_progs_parallel on x86_64 with gcc |
| bpf/vmtest-bpf-next-VM_Test-26 | success | Logs for test_verifier on s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-12 | success | Logs for test_progs on s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-16 | success | Logs for test_progs_no_alu32 on s390x with gcc |
| bpf/vmtest-bpf-next-VM_Test-8 | success | Logs for test_maps on s390x with gcc |
On Mon, Jul 24, 2023 at 1:13 PM Ian Rogers <irogers@google.com> wrote: > > With GCC LTO a potential use uninitialized is spotted: > ``` > In function ‘parse_events_config_bpf’, > inlined from ‘parse_events_load_bpf’ at util/parse-events.c:874:8: > util/parse-events.c:792:37: error: ‘error_pos’ may be used uninitialized [-Werror=maybe-uninitialized] > 792 | idx = term->err_term + error_pos; > | ^ > util/parse-events.c: In function ‘parse_events_load_bpf’: > util/parse-events.c:765:13: note: ‘error_pos’ was declared here > 765 | int error_pos; > | ^ > ``` > So initialize at declaration. This common pattern in C is error prone (conditional assignment in the callee; callers maybe forget to initialize, then unconditionally use the value). Clang's static analyzer can spot these, but isn't run for tools/ AFAIK. Reviewed-by: Nick Desaulniers <ndesaulniers@google.com> > > Signed-off-by: Ian Rogers <irogers@google.com> > --- > tools/perf/util/parse-events.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c > index acde097e327c..da29061ecf49 100644 > --- a/tools/perf/util/parse-events.c > +++ b/tools/perf/util/parse-events.c > @@ -762,7 +762,7 @@ parse_events_config_bpf(struct parse_events_state *parse_state, > struct list_head *head_config) > { > struct parse_events_term *term; > - int error_pos; > + int error_pos = 0; > > if (!head_config || list_empty(head_config)) > return 0; > -- > 2.41.0.487.g6d72f3e995-goog >
diff --git a/tools/perf/util/parse-events.c b/tools/perf/util/parse-events.c index acde097e327c..da29061ecf49 100644 --- a/tools/perf/util/parse-events.c +++ b/tools/perf/util/parse-events.c @@ -762,7 +762,7 @@ parse_events_config_bpf(struct parse_events_state *parse_state, struct list_head *head_config) { struct parse_events_term *term; - int error_pos; + int error_pos = 0; if (!head_config || list_empty(head_config)) return 0;
With GCC LTO a potential use uninitialized is spotted: ``` In function ‘parse_events_config_bpf’, inlined from ‘parse_events_load_bpf’ at util/parse-events.c:874:8: util/parse-events.c:792:37: error: ‘error_pos’ may be used uninitialized [-Werror=maybe-uninitialized] 792 | idx = term->err_term + error_pos; | ^ util/parse-events.c: In function ‘parse_events_load_bpf’: util/parse-events.c:765:13: note: ‘error_pos’ was declared here 765 | int error_pos; | ^ ``` So initialize at declaration. Signed-off-by: Ian Rogers <irogers@google.com> --- tools/perf/util/parse-events.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)