diff options
| author | Ihor Solodrai <ihor.solodrai@linux.dev> | 2026-02-23 22:07:33 +0300 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2026-02-24 19:19:49 +0300 |
| commit | 3e711c8e4707c46cc45d9775b50204d0f2790d77 (patch) | |
| tree | cf6eb06de01427aa16955be4e0eaabf22ffe76e6 | |
| parent | 2bb270a0ac68990648c5e84abf73bb7493230ea6 (diff) | |
| download | linux-3e711c8e4707c46cc45d9775b50204d0f2790d77.tar.xz | |
selftests/bpf: Fix array bounds warning in jit_disasm_helpers
Compiler cannot infer upper bound for labels.cnt and warns about
potential buffer overflow in snprintf. Add an explicit bounds
check (... && i < MAX_LOCAL_LABELS) in the loop condition to fix the
warning.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
Link: https://lore.kernel.org/r/20260223190736.649171-18-ihor.solodrai@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| -rw-r--r-- | tools/testing/selftests/bpf/jit_disasm_helpers.c | 18 |
1 files changed, 9 insertions, 9 deletions
diff --git a/tools/testing/selftests/bpf/jit_disasm_helpers.c b/tools/testing/selftests/bpf/jit_disasm_helpers.c index febd6b12e372..364c557c5115 100644 --- a/tools/testing/selftests/bpf/jit_disasm_helpers.c +++ b/tools/testing/selftests/bpf/jit_disasm_helpers.c @@ -122,15 +122,15 @@ static int disasm_one_func(FILE *text_out, uint8_t *image, __u32 len) pc += cnt; } qsort(labels.pcs, labels.cnt, sizeof(*labels.pcs), cmp_u32); - for (i = 0; i < labels.cnt; ++i) - /* gcc is unable to infer upper bound for labels.cnt and assumes - * it to be U32_MAX. U32_MAX takes 10 decimal digits. - * snprintf below prints into labels.names[*], - * which has space only for two digits and a letter. - * To avoid truncation warning use (i % MAX_LOCAL_LABELS), - * which informs gcc about printed value upper bound. - */ - snprintf(labels.names[i], sizeof(labels.names[i]), "L%d", i % MAX_LOCAL_LABELS); + /* gcc is unable to infer upper bound for labels.cnt and + * assumes it to be U32_MAX. U32_MAX takes 10 decimal digits. + * snprintf below prints into labels.names[*], which has space + * only for two digits and a letter. To avoid truncation + * warning use (i < MAX_LOCAL_LABELS), which informs gcc about + * printed value upper bound. + */ + for (i = 0; i < labels.cnt && i < MAX_LOCAL_LABELS; ++i) + snprintf(labels.names[i], sizeof(labels.names[i]), "L%d", i); /* now print with labels */ labels.print_phase = true; |