On Thu, 26 Dec 2024 14:15:25 +0900
"Masami Hiramatsu (Google)" <mhiramat@xxxxxxxxxx> wrote:
> From: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
>
> Add ftrace_get_entry_ip() which is only for ftrace based probes, and use
> it for kprobe multi probes because they are based on fprobe which uses
> ftrace instead of kprobes.
>
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
On my 32bit build, I hit a new warning;
kernel/trace/bpf_trace.c:1073:22: warning: ‘ftrace_get_entry_ip’ defined but not used [-Wunused-function]
1073 | static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
| ^~~~~~~~~~~~~~~~~~~
Config attached.
-- Steve
> ---
> Changes in v21:
> - Use new ftreace_get_symaddr() only for kprobe multi probes.
> Changes in v19:
> - Use ftrace_get_symaddr() instead of introducing new arch dependent code.
> - Also, replace x86 code with ftrace_get_symaddr(), which does the same
> thing.
> ---
> kernel/trace/bpf_trace.c | 13 +++++++++++--
> 1 file changed, 11 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
> index 863351559334..47beb70187d7 100644
> --- a/kernel/trace/bpf_trace.c
> +++ b/kernel/trace/bpf_trace.c
> @@ -1070,6 +1070,13 @@ static unsigned long get_entry_ip(unsigned long fentry_ip)
> #define get_entry_ip(fentry_ip) fentry_ip
> #endif
>
> +static unsigned long ftrace_get_entry_ip(unsigned long fentry_ip)
> +{
> + unsigned long ip = ftrace_get_symaddr(fentry_ip);
> +
> + return ip ? : fentry_ip;
> +}
> +
> BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs)
> {
> struct bpf_trace_run_ctx *run_ctx __maybe_unused;
> @@ -2829,7 +2836,8 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip,
> int err;
>
> link = container_of(fp, struct bpf_kprobe_multi_link, fp);
> - err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs, false, data);
> + err = kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
> + fregs, false, data);
> return is_kprobe_session(link->link.prog) ? err : 0;
> }
>
> @@ -2841,7 +2849,8 @@ kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip,
> struct bpf_kprobe_multi_link *link;
>
> link = container_of(fp, struct bpf_kprobe_multi_link, fp);
> - kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), fregs, true, data);
> + kprobe_multi_link_prog_run(link, ftrace_get_entry_ip(fentry_ip),
> + fregs, true, data);
> }
>
> static int symbols_cmp_r(const void *a, const void *b, const void *priv)
Attachment:
config
Description: Binary data
