Commit 5e37460f authored by Ye Bin's avatar Ye Bin Committed by Masami Hiramatsu (Google)
Browse files

Documentation: tracing: add new type '%pd' and '%pD' for kprobe 

Similar to printk() '%pd' is for fetch dentry's name from struct dentry's
pointer, and '%pD' is for fetch file's name from struct file's pointer.

Link: https://lore.kernel.org/all/20240322064308.284457-4-yebin10@huawei.com/



Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Acked-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: default avatarMasami Hiramatsu (Google) <mhiramat@kernel.org>
parent 20fe4d07

Documentation/trace/kprobetrace.rst

+6 −2
Original line number Diff line number Diff line
@@ -58,8 +58,9 @@ Synopsis of kprobe_events 
  NAME=FETCHARG : Set NAME as the argument name of FETCHARG.

  FETCHARG:TYPE : Set TYPE as the type of FETCHARG. Currently, basic types

		  (u8/u16/u32/u64/s8/s16/s32/s64), hexadecimal types

		  (x8/x16/x32/x64), "char", "string", "ustring", "symbol", "symstr"

                  and bitfield are supported.

		  (x8/x16/x32/x64), VFS layer common type(%pd/%pD), "char",

                  "string", "ustring", "symbol", "symstr" and bitfield are

                  supported.



  (\*1) only for the probe on function entry (offs == 0). Note, this argument access

        is best effort, because depending on the argument type, it may be passed on
@@ -122,6 +123,9 @@ With 'symstr' type, you can filter the event with wildcard pattern of the 
symbols, and you don't need to solve symbol name by yourself.

For $comm, the default type is "string"; any other type is invalid.



VFS layer common type(%pd/%pD) is a special type, which fetches dentry's or

file's name from struct dentry's address or struct file's address.



.. _user_mem_access:



User Memory Access