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[v4,1/9] Documentation: probes: Add a new ret_ip callback parameter

Message ID 169280373992.282662.14835192462715188987.stgit@devnote2 (mailing list archive)
State Not Applicable
Delegated to: BPF
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Series bpf: fprobe: rethook: Use ftrace_regs instead of pt_regs | expand

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Commit Message

Masami Hiramatsu (Google) Aug. 23, 2023, 3:15 p.m. UTC 
From: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Add a new ret_ip callback parameter description.

Fixes: cb16330d1274 ("fprobe: Pass return address to the handlers")
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
---
 Changes in v4:
  - Update ret_ip description (Thanks Florent!)
---
 Documentation/trace/fprobe.rst |    8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

Comments

Florent Revest Aug. 25, 2023, 4:11 p.m. UTC | #1 
On Wed, Aug 23, 2023 at 5:15 PM Masami Hiramatsu (Google)
<mhiramat@kernel.org> wrote:
>
> From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
>
> Add a new ret_ip callback parameter description.
>
> Fixes: cb16330d1274 ("fprobe: Pass return address to the handlers")
> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>

Acked-by: Florent Revest <revest@chromium.org>
diff mbox series

Patch

diff --git a/Documentation/trace/fprobe.rst b/Documentation/trace/fprobe.rst
index 40dd2fbce861..5851a14eb893 100644
--- a/Documentation/trace/fprobe.rst
+++ b/Documentation/trace/fprobe.rst
@@ -91,9 +91,9 @@  The prototype of the entry/exit callback function are as follows:
 
 .. code-block:: c
 
- int entry_callback(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs, void *entry_data);
+ int entry_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct pt_regs *regs, void *entry_data);
 
- void exit_callback(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs, void *entry_data);
+ void exit_callback(struct fprobe *fp, unsigned long entry_ip, unsigned long ret_ip, struct pt_regs *regs, void *entry_data);
 
 Note that the @entry_ip is saved at function entry and passed to exit handler.
 If the entry callback function returns !0, the corresponding exit callback will be cancelled.
@@ -108,6 +108,10 @@  If the entry callback function returns !0, the corresponding exit callback will
         Note that this may not be the actual entry address of the function but
         the address where the ftrace is instrumented.
 
+@ret_ip
+        This is the return address that the traced function will return to,
+        somewhere in the caller. This can be used at both entry and exit.
+
 @regs
         This is the `pt_regs` data structure at the entry and exit. Note that
         the instruction pointer of @regs may be different from the @entry_ip