diff options
| author |  Masami Hiramatsu (Google) <mhiramat@kernel.org>
| 2022-11-14 13:47:56 +0900 |
|---|---|---|
| committer | Masami Hiramatsu (Google) <mhiramat@kernel.org>
| 2022-12-15 08:48:57 +0900 |
| commit | b26a124cbfa80f42bfc4e63e1d5643ca98159d66 (patch) | |
| tree | 7ee46364505d3e2947596f13b731c752907f724e /kernel/trace/trace.c | |
| parent | kprobes: kretprobe events missing on 2-core KVM guest (diff) | |
| download | linux-b26a124cbfa80f42bfc4e63e1d5643ca98159d66.tar.gz linux-b26a124cbfa80f42bfc4e63e1d5643ca98159d66.tar.bz2 linux-b26a124cbfa80f42bfc4e63e1d5643ca98159d66.zip | |
tracing/probes: Add symstr type for dynamic events
Add 'symstr' type for storing the kernel symbol as a string data
instead of the symbol address. This allows us to filter the
events by wildcard symbol name.
e.g.
# echo 'e:wqfunc workqueue.workqueue_execute_start symname=$function:symstr' >> dynamic_events
# cat events/eprobes/wqfunc/format
name: wqfunc
ID: 2110
format:
field:unsigned short common_type; offset:0; size:2; signed:0;
field:unsigned char common_flags; offset:2; size:1; signed:0;
field:unsigned char common_preempt_count; offset:3; size:1; signed:0;
field:int common_pid; offset:4; size:4; signed:1;
field:__data_loc char[] symname; offset:8; size:4; signed:1;
print fmt: " symname=\"%s\"", __get_str(symname)
Note that there is already 'symbol' type which just change the
print format (so it still stores the symbol address in the tracing
ring buffer.) On the other hand, 'symstr' type stores the actual
"symbol+offset/size" data as a string.
Link: https://lore.kernel.org/all/166679930847.1528100.4124308529180235965.stgit@devnote3/
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 c6c7a0af3ed2..9ee519ad164e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5608,7 +5608,7 @@ static const char readme_msg[] = "\t +|-[u]<offset>(<fetcharg>), \\imm-value, \\\"imm-string\"\n" "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string, symbol,\n" "\t b<bit-width>@<bit-offset>/<container-size>, ustring,\n" - "\t <type>\\[<array-size>\\]\n" + "\t symstr, <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" |