diff options
| author | Ye Bin <yebin10@huawei.com> | 2024-03-22 07:43:05 +0100 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org> | 2024-05-01 16:18:47 +0200 |
| commit | 20fe4d07bde67ec26716835b61be2c4eeca1c6bc (patch) | |
| tree | 240fd448fd6c2231ccd8a7ce48681d441440ea79 /kernel/trace/trace.c | |
| parent | tracing/probes: support '%pd' type for print struct dentry's name (diff) | |
| download | linux-20fe4d07bde67ec26716835b61be2c4eeca1c6bc.tar.xz linux-20fe4d07bde67ec26716835b61be2c4eeca1c6bc.zip | |
tracing/probes: support '%pD' type for print struct file's name
As like '%pd' type, this patch supports print type '%pD' for print file's
name. For example "name=$arg1:%pD" casts the `$arg1` as (struct file*),
dereferences the "file.f_path.dentry.d_name.name" field and stores it to
"name" argument as a kernel string.
Here is an example:
[tracing]# echo 'p:testprobe vfs_read name=$arg1:%pD' > kprobe_event
[tracing]# echo 1 > events/kprobes/testprobe/enable
[tracing]# grep -q "1" events/kprobes/testprobe/enable
[tracing]# echo 0 > events/kprobes/testprobe/enable
[tracing]# grep "vfs_read" trace | grep "enable"
grep-15108 [003] ..... 5228.328609: testprobe: (vfs_read+0x4/0xbb0) name="enable"
Note that this expects the given argument (e.g. $arg1) is an address of struct
file. User must ensure it.
Link: https://lore.kernel.org/all/20240322064308.284457-3-yebin10@huawei.com/
[Masami: replaced "previous patch" with '%pd' type]
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>
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 869978d84672..7fe4b539a423 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5540,7 +5540,7 @@ static const char readme_msg[] = "\t kernel return probes support: $retval, $arg<N>, $comm\n" "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, char, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" - "\t symstr, %pd, <type>\\[<array-size>\\]\n" + "\t symstr, %pd/%pD, <type>\\[<array-size>\\]\n" #ifdef CONFIG_HIST_TRIGGERS "\t field: <stype> <name>;\n" "\t stype: u8/u16/u32/u64, s8/s16/s32/s64, pid_t,\n" |