From 5e37460f5f9266bcd037137f1bd9eb24b9940faf Mon Sep 17 00:00:00 2001 From: Ye Bin <yebin10@huawei.com> Date: Fri, 22 Mar 2024 14:43:06 +0800 Subject: 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: Ye Bin <yebin10@huawei.com> Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> --- Documentation/trace/kprobetrace.rst | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'Documentation') diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst index a49662ccd53c..195c942d9bec 100644 --- a/Documentation/trace/kprobetrace.rst +++ b/Documentation/trace/kprobetrace.rst @@ -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 -- cgit v1.2.3