From 502686233493deca7a516234dd041e22eef97c8b Mon Sep 17 00:00:00 2001 From: Kumar Kartikeya Dwivedi Date: Thu, 13 Aug 2026 00:19:21 +0200 Subject: [PATCH] selftests/bpf: Adjust veristat stack depth parsing The verifier now reports instruction and stack depth statistics using uniform "subprog () " records. Subprogram 0 is classified as main, while other records are global or static. Each record carries insns_self, insns_total, and stack depth. Teach veristat to parse the new records while retaining support for the legacy one-line stack depth format used by older kernels. Skip both instruction counts and match only through the stack value so fields can still be appended without breaking parsing. Increase the bounded backward scan so it can include all 256 per-subprogram records. Zero-initialize the legacy stack buffer because logs using the new format do not populate it before the trailing tokenizer loop. This makes the loop see an empty string instead of reading uninitialized data. Signed-off-by: Kumar Kartikeya Dwivedi Acked-by: Eduard Zingerman Link: https://patch.msgid.link/20260812221925.3358041-5-memxor@gmail.com Signed-off-by: Eduard Zingerman --- tools/testing/selftests/bpf/veristat.c | 23 +++++++++++++++++++---- 1 file changed, 19 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/bpf/veristat.c b/tools/testing/selftests/bpf/veristat.c index c9c257784ee3..5c0ec3edce72 100644 --- a/tools/testing/selftests/bpf/veristat.c +++ b/tools/testing/selftests/bpf/veristat.c @@ -993,13 +993,15 @@ static void free_verif_stats(struct verif_stats *stats, size_t stat_cnt) static char verif_log_buf[64 * 1024]; -#define MAX_PARSED_LOG_LINES 100 +/* Keep room for all 256 subprogram records and trailing statistics. */ +#define MAX_PARSED_LOG_LINES 300 static int parse_verif_log(char * const buf, size_t buf_sz, struct verif_stats *s) { const char *cur; - int pos, lines, sub_stack, cnt = 0; - char *state = NULL, *token, stack[512]; + long sub_stack; + int pos, lines, cnt = 0; + char *state = NULL, *token, stack[512] = {}; buf[buf_sz - 1] = '\0'; @@ -1025,11 +1027,24 @@ static int parse_verif_log(char * const buf, size_t buf_sz, struct verif_stats * &s->stats[MARK_READ_MAX_LEN])) continue; + /* + * New kernels emit one "subprog () " record + * per subprogram with the stack depth at the end, while old + * kernels emit a single "stack depth max " + * line. Match both formats so veristat works against either + * kernel. + */ + if (sscanf(cur, "stack depth max %ld", &s->stats[MAX_STACK]) == 1) + continue; + if (sscanf(cur, "subprog %*d %*s %*s insns_self %*d insns_total %*d stack %ld", &sub_stack) == 1) { + s->stats[STACK] += sub_stack; + continue; + } if (2 == sscanf(cur, "stack depth %511s max %ld", stack, &s->stats[MAX_STACK])) continue; } while ((token = strtok_r(cnt++ ? NULL : stack, "+", &state))) { - if (sscanf(token, "%d", &sub_stack) == 0) + if (sscanf(token, "%ld", &sub_stack) == 0) break; s->stats[STACK] += sub_stack; }