Hi Jiri,
On Thu, 11 Aug 2022 11:15:21 +0200
Jiri Olsa <jolsa@xxxxxxxxxx> wrote:
> Adding KPROBE_FLAG_ON_FUNC_ENTRY kprobe flag to indicate that
> attach address is on function entry. This is used in following
> changes in get_func_ip helper to return correct function address.
Sorry about late reply.
>
> Signed-off-by: Jiri Olsa <jolsa@xxxxxxxxxx>
> ---
> include/linux/kprobes.h | 1 +
> kernel/kprobes.c | 6 +++++-
> 2 files changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/include/linux/kprobes.h b/include/linux/kprobes.h
> index 55041d2f884d..a0b92be98984 100644
> --- a/include/linux/kprobes.h
> +++ b/include/linux/kprobes.h
> @@ -103,6 +103,7 @@ struct kprobe {
> * this flag is only for optimized_kprobe.
> */
> #define KPROBE_FLAG_FTRACE 8 /* probe is using ftrace */
> +#define KPROBE_FLAG_ON_FUNC_ENTRY 16 /* probe is on the function entry */
>
> /* Has this kprobe gone ? */
> static inline bool kprobe_gone(struct kprobe *p)
> diff --git a/kernel/kprobes.c b/kernel/kprobes.c
> index f214f8c088ed..a6b1b5c49d92 100644
> --- a/kernel/kprobes.c
> +++ b/kernel/kprobes.c
> @@ -1605,9 +1605,10 @@ int register_kprobe(struct kprobe *p)
> struct kprobe *old_p;
> struct module *probed_mod;
> kprobe_opcode_t *addr;
> + bool on_func_entry;
>
> /* Adjust probe address from symbol */
> - addr = kprobe_addr(p);
> + addr = _kprobe_addr(p->addr, p->symbol_name, p->offset, &on_func_entry);
Hmm, OK. And I think now we can remove kprobe_addr() itself. It is still
used in register_kretprobe() but that is redundant.
Anyway, this patch itself looks good to me.
Acked-by: Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
Thank you!
> if (IS_ERR(addr))
> return PTR_ERR(addr);
> p->addr = addr;
> @@ -1627,6 +1628,9 @@ int register_kprobe(struct kprobe *p)
>
> mutex_lock(&kprobe_mutex);
>
> + if (on_func_entry)
> + p->flags |= KPROBE_FLAG_ON_FUNC_ENTRY;
> +
> old_p = get_kprobe(p->addr);
> if (old_p) {
> /* Since this may unoptimize 'old_p', locking 'text_mutex'. */
> --
> 2.37.1
>
--
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
