On Wed, 2024-08-21 at 13:08 -0700, Andrii Nakryiko wrote:
[...]
> Ok, then let's do that. I don't want static analysers complaining
> about this when checking libbpf code base.
Just want to rant a bit.
Here is a footgun in the relo_core.c:
#ifdef __KERNEL__
...
#undef pr_warn
#undef pr_info
#undef pr_debug
#define pr_warn(fmt, log, ...) bpf_log((void *)log, fmt, "", ##__VA_ARGS__)
#define pr_info(fmt, log, ...) bpf_log((void *)log, fmt, "", ##__VA_ARGS__)
#define pr_debug(fmt, log, ...) bpf_log((void *)log, fmt, "", ##__VA_ARGS__)
^^^ ^^^^^^^^^^^ ^^
first format param, prog_name replacement for
usually prog_name cast to first param
verifier log
...
#else
...
#endif
int bpf_core_calc_relo_insn(const char *prog_name, ...)
{
...
pr_warn("prog '%s': relo #%d: bad type id %u\n",
prog_name, relo_idx, local_id);
...
}
And in the verifier.c:
err = bpf_core_calc_relo_insn((void *)ctx->log, relo, ...);
^^^^^^^^^^^^^^^^
This is a prog_name parameter
Just spent more than an hour trying to figure out why passing real
program name (char *) does not work.
I'll think on a refactoring, but that is for another series.
