selftests/bpf: Adjust veristat stack depth parsing

The verifier now reports instruction and stack depth statistics using
uniform "subprog <id> (<name>) <kind>" 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 <memxor@gmail.com>
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://patch.msgid.link/20260812221925.3358041-5-memxor@gmail.com
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>

0 files changed, 0 insertions, 0 deletions