From: Steven Rostedt <rostedt@goodmis.org>
To: linux-kernel@vger.kernel.org
Cc: Ingo Molnar <mingo@kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: [for-next][PATCH 16/26] tracing/kprobes: Support perf-style return probe
Date: Mon, 21 Sep 2020 21:24:30 -0400 [thread overview]
Message-ID: <20200922012452.322184057@goodmis.org> (raw)
In-Reply-To: 20200922012414.115238201@goodmis.org
From: Masami Hiramatsu <mhiramat@kernel.org>
Support perf-style return probe ("SYMBOL%return") for kprobe events.
This will allow boot-time tracing user to define a return probe event.
Link: https://lkml.kernel.org/r/159972813535.428528.4437029657208468954.stgit@devnote2
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
---
kernel/trace/trace.c | 2 +-
kernel/trace/trace_kprobe.c | 18 +++++++++++++++++-
kernel/trace/trace_probe.h | 1 +
3 files changed, 19 insertions(+), 2 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 55b829863127..ca6da462326d 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5122,7 +5122,7 @@ static const char readme_msg[] =
"\t -:[<group>/]<event>\n"
#ifdef CONFIG_KPROBE_EVENTS
"\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n"
- "place (kretprobe): [<module>:]<symbol>[+<offset>]|<memaddr>\n"
+ "place (kretprobe): [<module>:]<symbol>[+<offset>]%return|<memaddr>\n"
#endif
#ifdef CONFIG_UPROBE_EVENTS
" place (uprobe): <path>:<offset>[(ref_ctr_offset)]\n"
diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c
index f8e46929ceba..9d46415296eb 100644
--- a/kernel/trace/trace_kprobe.c
+++ b/kernel/trace/trace_kprobe.c
@@ -718,6 +718,9 @@ static int trace_kprobe_create(int argc, const char *argv[])
* p[:[GRP/]EVENT] [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
* - Add kretprobe:
* r[MAXACTIVE][:[GRP/]EVENT] [MOD:]KSYM[+0] [FETCHARGS]
+ * Or
+ * p:[GRP/]EVENT] [MOD:]KSYM[+0]%return [FETCHARGS]
+ *
* Fetch args:
* $retval : fetch return value
* $stack : fetch stack address
@@ -747,7 +750,6 @@ static int trace_kprobe_create(int argc, const char *argv[])
switch (argv[0][0]) {
case 'r':
is_return = true;
- flags |= TPARG_FL_RETURN;
break;
case 'p':
break;
@@ -805,12 +807,26 @@ static int trace_kprobe_create(int argc, const char *argv[])
symbol = kstrdup(argv[1], GFP_KERNEL);
if (!symbol)
return -ENOMEM;
+
+ tmp = strchr(symbol, '%');
+ if (tmp) {
+ if (!strcmp(tmp, "%return")) {
+ *tmp = '\0';
+ is_return = true;
+ } else {
+ trace_probe_log_err(tmp - symbol, BAD_ADDR_SUFFIX);
+ goto parse_error;
+ }
+ }
+
/* TODO: support .init module functions */
ret = traceprobe_split_symbol_offset(symbol, &offset);
if (ret || offset < 0 || offset > UINT_MAX) {
trace_probe_log_err(0, BAD_PROBE_ADDR);
goto parse_error;
}
+ if (is_return)
+ flags |= TPARG_FL_RETURN;
if (kprobe_on_func_entry(NULL, symbol, offset))
flags |= TPARG_FL_FENTRY;
if (offset && is_return && !(flags & TPARG_FL_FENTRY)) {
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index a22b62813f8c..04d00987da69 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -404,6 +404,7 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(MAXACT_TOO_BIG, "Maxactive is too big"), \
C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
+ C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
C(NO_GROUP_NAME, "Group name is not specified"), \
C(GROUP_TOO_LONG, "Group name is too long"), \
C(BAD_GROUP_NAME, "Group name must follow the same rules as C identifiers"), \
--
2.28.0
next prev parent reply other threads:[~2020-09-22 1:25 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-22 1:24 [for-next][PATCH 00/26] tracing: Updates for 5.10 Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 01/26] tools/bootconfig: Show bootconfig compact tree from bootconfig file Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 02/26] tools/bootconfig: Add list option Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 03/26] tools/bootconfig: Make all functions static Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 04/26] tools/bootconfig: Add a script to generate ftrace shell-command from bootconfig Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 05/26] tools/bootconfig: Add a script to generates bootconfig from ftrace Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 06/26] tools/bootconfig: Add --init option for bconf2ftrace.sh Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 07/26] tracing: toplevel d_entry already initialized Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 08/26] tracing: make tracing_init_dentry() returns an integer instead of a d_entry pointer Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 09/26] tracing: Delete repeated words in comments Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 10/26] tracing: Use __this_cpu_read() in trace_buffered_event_enable() Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 11/26] kprobes: Use module_name() macro Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 12/26] tracing: remove a pointless assignment Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 13/26] fgraph: Convert ret_stack tasklist scanning to rcu Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 14/26] tracing/boot: Add per-instance tracing_on option support Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 15/26] Documentation: tracing: Add tracing_on option to boot-time tracer Steven Rostedt
2020-09-22 1:24 ` Steven Rostedt [this message]
2020-09-22 1:24 ` [for-next][PATCH 17/26] tracing/uprobes: Support perf-style return probe Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 18/26] Documentation: tracing: Add %return suffix description Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 19/26] Documentation: tracing: boot: Add an example of tracing function-calls Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 20/26] selftests/ftrace: Add %return suffix tests Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 21/26] kprobes: Init kprobes in early_initcall Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 22/26] tracing: Define event fields early stage Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 23/26] tracing: Enable adding dynamic events " Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 24/26] tracing: Enable creating new instance early boot Steven Rostedt
2020-09-23 23:52 ` Masami Hiramatsu
2020-09-24 16:40 ` [PATCH] tracing/boot: Initialize per-instance event list in " Masami Hiramatsu
2020-09-25 19:37 ` Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 25/26] tracing/boot, kprobe, synth: Initialize boot-time tracing earlier Steven Rostedt
2020-09-22 1:24 ` [for-next][PATCH 26/26] Documentation: tracing: Add the startup timing of boot-time tracing Steven Rostedt
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