Re: [PATCH bpf-next v1 1/3] bpf: Extract bpf_get_linfo_file_line

Mykyta Yatsenko
2026-03-30T11:28:06Z

Kumar Kartikeya Dwivedi <memxor@gmail.com> writes:

> Extract bpf_get_linfo_file_line as its own function so that the logic to
> obtain the file, line, and line number for a given program can be shared
> in subsequent patches.
>
> Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
> ---
The patch extracted bpf_get_linfo_file_line() and modified it slightly
to support optional output arguments.
Acked-by: Mykyta Yatsenko <yatsenko@meta.com>
> include/linux/bpf.h | 2 ++
> kernel/bpf/core.c | 32 +++++++++++++++++++++++---------
> 2 files changed, 25 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/bpf.h b/include/linux/bpf.h
> index 05b34a6355b0..2c4f92085d79 100644
> --- a/include/linux/bpf.h
> +++ b/include/linux/bpf.h
> @@ -3946,6 +3946,8 @@ static inline bool bpf_is_subprog(const struct bpf_prog *prog)
> return prog->aux->func_idx != 0;
> }
>
> +int bpf_get_linfo_file_line(struct btf *btf, const struct bpf_line_info *linfo,
> + const char **filep, const char **linep, int *nump);
> int bpf_prog_get_file_line(struct bpf_prog *prog, unsigned long ip, const char **filep,
> const char **linep, int *nump);
> struct bpf_prog *bpf_prog_find_from_stack(void);
> diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
> index 1af5fb3f21d9..052dd78a2d81 100644
> --- a/kernel/bpf/core.c
> +++ b/kernel/bpf/core.c
> @@ -3313,6 +3313,28 @@ EXPORT_TRACEPOINT_SYMBOL_GPL(xdp_bulk_tx);
>
> #ifdef CONFIG_BPF_SYSCALL
>
> +int bpf_get_linfo_file_line(struct btf *btf, const struct bpf_line_info *linfo,
> + const char **filep, const char **linep, int *nump)
> +{
> + /* Get base component of the file path. */
> + if (filep) {
> + *filep = btf_name_by_offset(btf, linfo->file_name_off);
> + *filep = kbasename(*filep);
> + }
> +
> + /* Obtain the source line, and strip whitespace in prefix. */
> + if (linep) {
> + *linep = btf_name_by_offset(btf, linfo->line_off);
> + while (isspace(**linep))
> + *linep += 1;
> + }
> +
> + if (nump)
> + *nump = BPF_LINE_INFO_LINE_NUM(linfo->line_col);
> +
> + return 0;
> +}
> +
> int bpf_prog_get_file_line(struct bpf_prog *prog, unsigned long ip, const char **filep,
> const char **linep, int *nump)
> {
> @@ -3347,15 +3369,7 @@ int bpf_prog_get_file_line(struct bpf_prog *prog, unsigned long ip, const char *
> if (idx == -1)
> return -ENOENT;
>
> - /* Get base component of the file path. */
> - *filep = btf_name_by_offset(btf, linfo[idx].file_name_off);
> - *filep = kbasename(*filep);
> - /* Obtain the source line, and strip whitespace in prefix. */
> - *linep = btf_name_by_offset(btf, linfo[idx].line_off);
> - while (isspace(**linep))
> - *linep += 1;
> - *nump = BPF_LINE_INFO_LINE_NUM(linfo[idx].line_col);
> - return 0;
> + return bpf_get_linfo_file_line(btf, &linfo[idx], filep, linep, nump);
> }
>
> struct walk_stack_ctx {
> --
> 2.52.0