Documentation/trace/fprobetrace.rst | 17 +- kernel/trace/trace.c | 3 +- kernel/trace/trace_fprobe.c | 209 ++++++++++++++---- .../ftrace/test.d/dynevent/fprobe_list.tc | 92 ++++++++ 4 files changed, 269 insertions(+), 52 deletions(-) create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
Extend fprobe to support list-style filters and explicit entry/exit suffixes.
Currentyl, fprobe only supports a single symbol (or wildcard) per event.
This patch allows users to specify a comma-separated list of symbols.
New Syntax:
- f:[GRP/][EVENT] func1,func2,func3:entry
- f:[GRP/][EVENT] func1,func2,func3:exit
Logic changes:
- Refactor parsing logic into 'parse_fprobe_spec'
- Support '!' prefix for exclusion
- Disable BTF lookup ('ctx->funcname = NULL') when a list or wildcard is used,
as a single function signature cannot apply to multiple functions.
- Reject legacy '%return' suffix when used with lists or wildcards
- Update tracefs/README
Testing:
Verified on x86_64 via QEMU. Checked registration of lists, exclusions, and
explicit suffixes. Verified rejection of invalid syntax including trailing
commas and mixed legacy/new syntax.
Seokwoo Chung (Ryan) (3):
docs: tracing/fprobe: Document list filters and :entry/:exit
tracing/fprobe: Support comma-separated symbols and :entry/:exit
selftests/ftrace: Add accept cases for fprobe list syntax
Changes in v4:
- Added validation to reject trailing commas (empty tokens) in symbol lists
- Added vaildation to reject mixed of list syntax with %return suffix
- Refactored parse_fprobe_spec to user __free(kfree) for automatic memory
cleanup
- Removed the now-unused parse_symbol_and_return function to avoid compiler
warnings.
- Tigtened %return detection to ensure it only matches as a strict suffix, not a
substring
- Link to v3: https://lore.kernel.org/lkml/20250904103219.f4937968362bfff1ecd3f004@kernel.org/
Documentation/trace/fprobetrace.rst | 17 +-
kernel/trace/trace.c | 3 +-
kernel/trace/trace_fprobe.c | 209 ++++++++++++++----
.../ftrace/test.d/dynevent/fprobe_list.tc | 92 ++++++++
4 files changed, 269 insertions(+), 52 deletions(-)
create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
--
2.43.0
This series extends fprobe dynamic events to accept a comma-separated list of symbols and explicit/suffixes. Currently, fprobe only supports a single symbol (or wildcard) per event. This series allow users to specify a comma-separated list of symbols, including exclusions, and to select entry/exit explicitly using / Examples: - f:[GRP/][EVENT] func1,func2,func3 - f:[GRP/][EVENT] func1,!func2,func3 (exclude with '!') Logic changes: - Refactor parsing logic into parse_fprobe_spec() - Support comma-separated lists and '!' exclusions - Add / suffixes for explicit entry/exit selection - Preserve legacy single-symbol behavior (single symbols still accept %return) - Disable BTF-based signature lookup when list/wildcard is used, since one function signature cannot apply to multiple functions - Reject mixed legacy/new syntax where applicable (e.g. list + %return) - Update tracefs/README and fprobe documentation - Add ftrace selftests covering accepted list syntax cases *Patch order is adjusted: code first, then docs, then selftest Changes in v5: - Reordered patches (code->docs->selftests) as suggested - Addressed review feedback on README help text to show both legacy and list syntaxes - Added missing traceprobe error IDs used by the new validation and fixed parsing/bracing issues found by automated builds - Removed the dedicated list_mode field and infer list behavior from presence of filter/nofilter and keep struct trace_probe as the last member - Link to v4: https://lore.kernel.org/linux-trace-kernel/20251127151218.4763b25c751bb2aac4b1ee36@kernel.org/ I am not fully confident the runtime testing coverage that I did is sufficient across configs/architectures, so additional verification would be appreciated. Best regards, Ryan Chung Seokwoo Chung (Ryan) (3): tracing/fprobe: Support comma-separated symbols and :entry/:exit docs: tracing/fprobe: Document list filters and :entry/:exit selftests/ftrace: Add accept cases for fprobe list syntax Documentation/trace/fprobetrace.rst | 18 +++++-- kernel/trace/trace.c | 4 +- kernel/trace/trace_fprobe.c | 49 ++++++++++--------- kernel/trace/trace_probe.h | 2 + .../ftrace/test.d/dynevent/fprobe_list.tc | 2 +- 5 files changed, 47 insertions(+), 28 deletions(-) base-commit: f0c13b210e4366e03bd9e8967347b06b227e20a4 -- 2.43.0
Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
---
kernel/trace/trace.c | 4 +--
kernel/trace/trace_fprobe.c | 49 ++++++++++++++++++++-----------------
kernel/trace/trace_probe.h | 2 ++
3 files changed, 31 insertions(+), 24 deletions(-)
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 10cdcc7b194e..73b59d47dfe7 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5578,8 +5578,8 @@ static const char readme_msg[] =
"\t r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
#endif
#ifdef CONFIG_FPROBE_EVENTS
- "\t f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]\n"
- "\t (single symbols still accept %return)\n"
+ "\t f[:[<group>/][<event>]] <func-name>[%return] [<args>]\n"
+ "\t f[:[<group>/][<event>]] <func-list>[:entry|:exit] [<args>]\n"
"\t t[:[<group>/][<event>]] <tracepoint> [<args>]\n"
#endif
#ifdef CONFIG_HIST_TRIGGERS
diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
index 5a2a41eea603..1663c341ddb4 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -187,16 +187,23 @@ DEFINE_FREE(tuser_put, struct tracepoint_user *,
*/
struct trace_fprobe {
struct dyn_event devent;
- char *filter;
+
struct fprobe fp;
- bool list_mode;
- char *nofilter;
const char *symbol;
- struct trace_probe tp;
+ char *filter;
+ char *nofilter;
+
bool tprobe;
struct tracepoint_user *tuser;
+
+ struct trace_probe tp;
};
+static inline bool trace_fprobe_has_list(const struct trace_fprobe *tf)
+{
+ return tf->filter || tf->nofilter;
+}
+
static bool is_trace_fprobe(struct dyn_event *ev)
{
return ev->ops == &trace_fprobe_ops;
@@ -847,7 +854,7 @@ static int __register_trace_fprobe(struct trace_fprobe *tf)
* - list_mode: pass filter/nofilter
* - single: pass symbol only (legacy)
*/
- if (tf->list_mode)
+ if (trace_fprobe_has_list(tf))
return register_fprobe(&tf->fp, tf->filter, tf->nofilter);
return register_fprobe(&tf->fp, tf->symbol, NULL);
}
@@ -1188,11 +1195,18 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
*base = NULL; *filter = NULL; *nofilter = NULL;
*is_return = false; *list_mode = false;
- if (is_tracepoint) {
+ if (is_tracepoint)
+ {
if (strchr(in, ',') || strchr(in, ':'))
+ {
+ trace_probe_log_err(0, BAD_TP_NAME);
return -EINVAL;
+ }
if (strstr(in, "%return"))
+ {
+ trace_probe_log_err(p - in, BAD_TP_NAME);
return -EINVAL;
+ }
for (p = in; *p; p++)
if (!isalnum(*p) && *p != '_')
return -EINVAL;
@@ -1225,6 +1239,7 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
} else if (!strcmp(p, ":entry")) {
*(char *)p = '\0';
} else {
+ trace_probe_log_err(p - work, BAD_LIST_SUFFIX);
return -EINVAL;
}
}
@@ -1233,6 +1248,7 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
list = !!strchr(work, ',');
if (list && legacy_ret) {
+ trace_probe_log_err(p - work, BAD_LEGACY_RET);
return -EINVAL;
}
@@ -1245,12 +1261,9 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
if (list) {
char *tmp = b, *tok;
- size_t fsz, nfsz;
- fsz = nfsz = strlen(b) + 1;
-
- f = kzalloc(fsz, GFP_KERNEL);
- nf = kzalloc(nfsz, GFP_KERNEL);
+ f = kzalloc(strlen(b) + 1, GFP_KERNEL);
+ nf = kzalloc(strlen(b) + 1, GFP_KERNEL);
if (!f || !nf)
return -ENOMEM;
@@ -1261,6 +1274,7 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
if (*tok == '\0') {
trace_probe_log_err(tmp - b - 1, BAD_TP_NAME);
return -EINVAL;
+ }
if (neg)
tok++;
@@ -1455,17 +1469,8 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
/* carry list parsing result into tf */
if (!is_tracepoint) {
- tf->list_mode = list_mode;
- if (parsed_filter) {
- tf->filter = kstrdup(parsed_filter, GFP_KERNEL);
- if (!tf->filter)
- return -ENOMEM;
- }
- if (parsed_nofilter) {
- tf->nofilter = kstrdup(parsed_nofilter, GFP_KERNEL);
- if (!tf->nofilter)
- return -ENOMEM;
- }
+ tf->filter = no_free_ptr(parsed_filter);
+ tf->nofilter = no_free_ptr(parsed_nofilter);
}
/* parse arguments */
diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
index 9fc56c937130..b8b0544eb7cd 100644
--- a/kernel/trace/trace_probe.h
+++ b/kernel/trace/trace_probe.h
@@ -494,9 +494,11 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
C(NON_UNIQ_SYMBOL, "The symbol is not unique"), \
C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
+ C(BAD_LEGACY_RET, "Legacy %return not allowed with list"), \
C(NO_TRACEPOINT, "Tracepoint is not found"), \
C(BAD_TP_NAME, "Invalid character in tracepoint name"),\
C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
+ C(BAD_LIST_SUFFIX, "Bad list 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"), \
--
2.43.0On Wed, 14 Jan 2026 17:13:38 -0500
"Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote:
Missing change log. The subject is the "what" the patch is doing, the
change log needs the "why".
> Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
> ---
> kernel/trace/trace.c | 4 +--
> kernel/trace/trace_fprobe.c | 49 ++++++++++++++++++++-----------------
> kernel/trace/trace_probe.h | 2 ++
> 3 files changed, 31 insertions(+), 24 deletions(-)
>
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index 10cdcc7b194e..73b59d47dfe7 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5578,8 +5578,8 @@ static const char readme_msg[] =
> "\t r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
> #endif
> #ifdef CONFIG_FPROBE_EVENTS
> - "\t f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]\n"
> - "\t (single symbols still accept %return)\n"
> + "\t f[:[<group>/][<event>]] <func-name>[%return] [<args>]\n"
> + "\t f[:[<group>/][<event>]] <func-list>[:entry|:exit] [<args>]\n"
> "\t t[:[<group>/][<event>]] <tracepoint> [<args>]\n"
> #endif
> #ifdef CONFIG_HIST_TRIGGERS
> diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c
> index 5a2a41eea603..1663c341ddb4 100644
> --- a/kernel/trace/trace_fprobe.c
> +++ b/kernel/trace/trace_fprobe.c
> @@ -187,16 +187,23 @@ DEFINE_FREE(tuser_put, struct tracepoint_user *,
> */
> struct trace_fprobe {
> struct dyn_event devent;
> - char *filter;
> +
> struct fprobe fp;
> - bool list_mode;
> - char *nofilter;
> const char *symbol;
> - struct trace_probe tp;
> + char *filter;
> + char *nofilter;
> +
> bool tprobe;
> struct tracepoint_user *tuser;
> +
> + struct trace_probe tp;
Why is this being updated? Nothing in the change log says why?
> };
>
> +static inline bool trace_fprobe_has_list(const struct trace_fprobe *tf)
> +{
> + return tf->filter || tf->nofilter;
> +}
> +
> static bool is_trace_fprobe(struct dyn_event *ev)
> {
> return ev->ops == &trace_fprobe_ops;
> @@ -847,7 +854,7 @@ static int __register_trace_fprobe(struct trace_fprobe *tf)
> * - list_mode: pass filter/nofilter
> * - single: pass symbol only (legacy)
> */
> - if (tf->list_mode)
> + if (trace_fprobe_has_list(tf))
> return register_fprobe(&tf->fp, tf->filter, tf->nofilter);
> return register_fprobe(&tf->fp, tf->symbol, NULL);
> }
> @@ -1188,11 +1195,18 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
> *base = NULL; *filter = NULL; *nofilter = NULL;
> *is_return = false; *list_mode = false;
>
> - if (is_tracepoint) {
> + if (is_tracepoint)
> + {
> if (strchr(in, ',') || strchr(in, ':'))
> + {
> + trace_probe_log_err(0, BAD_TP_NAME);
> return -EINVAL;
> + }
> if (strstr(in, "%return"))
> + {
> + trace_probe_log_err(p - in, BAD_TP_NAME);
> return -EINVAL;
> + }
> for (p = in; *p; p++)
> if (!isalnum(*p) && *p != '_')
> return -EINVAL;
> @@ -1225,6 +1239,7 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
> } else if (!strcmp(p, ":entry")) {
> *(char *)p = '\0';
> } else {
> + trace_probe_log_err(p - work, BAD_LIST_SUFFIX);
> return -EINVAL;
> }
> }
> @@ -1233,6 +1248,7 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
> list = !!strchr(work, ',');
>
> if (list && legacy_ret) {
> + trace_probe_log_err(p - work, BAD_LEGACY_RET);
> return -EINVAL;
> }
>
> @@ -1245,12 +1261,9 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
>
> if (list) {
> char *tmp = b, *tok;
> - size_t fsz, nfsz;
>
> - fsz = nfsz = strlen(b) + 1;
> -
> - f = kzalloc(fsz, GFP_KERNEL);
> - nf = kzalloc(nfsz, GFP_KERNEL);
> + f = kzalloc(strlen(b) + 1, GFP_KERNEL);
> + nf = kzalloc(strlen(b) + 1, GFP_KERNEL);
> if (!f || !nf)
> return -ENOMEM;
>
> @@ -1261,6 +1274,7 @@ static int parse_fprobe_spec(const char *in, bool is_tracepoint,
> if (*tok == '\0') {
> trace_probe_log_err(tmp - b - 1, BAD_TP_NAME);
> return -EINVAL;
> + }
>
> if (neg)
> tok++;
> @@ -1455,17 +1469,8 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>
> /* carry list parsing result into tf */
> if (!is_tracepoint) {
> - tf->list_mode = list_mode;
> - if (parsed_filter) {
> - tf->filter = kstrdup(parsed_filter, GFP_KERNEL);
> - if (!tf->filter)
> - return -ENOMEM;
> - }
> - if (parsed_nofilter) {
> - tf->nofilter = kstrdup(parsed_nofilter, GFP_KERNEL);
> - if (!tf->nofilter)
> - return -ENOMEM;
> - }
> + tf->filter = no_free_ptr(parsed_filter);
> + tf->nofilter = no_free_ptr(parsed_nofilter);
> }
>
> /* parse arguments */
> diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h
> index 9fc56c937130..b8b0544eb7cd 100644
> --- a/kernel/trace/trace_probe.h
> +++ b/kernel/trace/trace_probe.h
> @@ -494,9 +494,11 @@ extern int traceprobe_define_arg_fields(struct trace_event_call *event_call,
> C(BAD_PROBE_ADDR, "Invalid probed address or symbol"), \
> C(NON_UNIQ_SYMBOL, "The symbol is not unique"), \
> C(BAD_RETPROBE, "Retprobe address must be an function entry"), \
> + C(BAD_LEGACY_RET, "Legacy %return not allowed with list"), \
> C(NO_TRACEPOINT, "Tracepoint is not found"), \
> C(BAD_TP_NAME, "Invalid character in tracepoint name"),\
> C(BAD_ADDR_SUFFIX, "Invalid probed address suffix"), \
> + C(BAD_LIST_SUFFIX, "Bad list 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"), \
This definitely needs discussion on why this is needed.
-- Steve
On Tue, 20 Jan 2026 15:50:47 -0500 Steven Rostedt <rostedt@goodmis.org> wrote: > On Wed, 14 Jan 2026 17:13:38 -0500 > "Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote: > > Missing change log. The subject is the "what" the patch is doing, the > change log needs the "why". Ah, just noticed you sent a revision. I'll reply there. -- Steve
Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
---
Documentation/trace/fprobetrace.rst | 18 +++++++++++++++---
1 file changed, 15 insertions(+), 3 deletions(-)
diff --git a/Documentation/trace/fprobetrace.rst b/Documentation/trace/fprobetrace.rst
index b4c2ca3d02c1..5efd9c374365 100644
--- a/Documentation/trace/fprobetrace.rst
+++ b/Documentation/trace/fprobetrace.rst
@@ -25,14 +25,19 @@ Synopsis of fprobe-events
-------------------------
::
- f[:[GRP1/][EVENT1]] SYM [FETCHARGS] : Probe on function entry
- f[MAXACTIVE][:[GRP1/][EVENT1]] SYM%return [FETCHARGS] : Probe on function exit
+ f[:[GRP1/][EVENT1]] SYM [FETCHARGS] : Probe on function entry
+ f[MAXACTIVE][:[GRP1/][EVENT1]] SYM%return [FETCHARGS] : Probe on function exit
+ f[:[GRP1/][EVENT1] SYM[,[!]SYM[,...][:entry|:exit] [FETCHARGS] : Probe on
+ list/wildcard
t[:[GRP2/][EVENT2]] TRACEPOINT [FETCHARGS] : Probe on tracepoint
GRP1 : Group name for fprobe. If omitted, use "fprobes" for it.
GRP2 : Group name for tprobe. If omitted, use "tracepoints" for it.
EVENT1 : Event name for fprobe. If omitted, the event name is
- "SYM__entry" or "SYM__exit".
+ - For a single literal symbol, the event name is
+ "SYM__entry" or "SYM__exit".
+ - For a *list or any wildcard*, an explicit [GRP1/][EVENT1] is
+ required.
EVENT2 : Event name for tprobe. If omitted, the event name is
the same as "TRACEPOINT", but if the "TRACEPOINT" starts
with a digit character, "_TRACEPOINT" is used.
@@ -40,6 +45,13 @@ Synopsis of fprobe-events
can be probed simultaneously, or 0 for the default value
as defined in Documentation/trace/fprobe.rst
+ SYM : Function name or comma-separated list of symbols.
+ - SYM prefixed with "!" are exclusions.
+ - ":entry" suffix means it probes entry of given symbols
+ (default)
+ - ":exit" suffix means it probes exit of given symbols.
+ - "%return" suffix means it probes exit of SYM (single
+ symbol).
FETCHARGS : Arguments. Each probe can have up to 128 args.
ARG : Fetch "ARG" function argument using BTF (only for function
entry or tracepoint.) (\*1)
--
2.43.0On Wed, 14 Jan 2026 17:13:39 -0500 "Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote: Again, no change log :-( -- Steve > Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com> > --- > Documentation/trace/fprobetrace.rst | 18 +++++++++++++++--- > 1 file changed, 15 insertions(+), 3 deletions(-) > > diff --git a/Documentation/trace/fprobetrace.rst b/Documentation/trace/fprobetrace.rst > index b4c2ca3d02c1..5efd9c374365 100644 > --- a/Documentation/trace/fprobetrace.rst > +++ b/Documentation/trace/fprobetrace.rst > @@ -25,14 +25,19 @@ Synopsis of fprobe-events > ------------------------- > :: > > - f[:[GRP1/][EVENT1]] SYM [FETCHARGS] : Probe on function entry > - f[MAXACTIVE][:[GRP1/][EVENT1]] SYM%return [FETCHARGS] : Probe on function exit > + f[:[GRP1/][EVENT1]] SYM [FETCHARGS] : Probe on function entry > + f[MAXACTIVE][:[GRP1/][EVENT1]] SYM%return [FETCHARGS] : Probe on function exit > + f[:[GRP1/][EVENT1] SYM[,[!]SYM[,...][:entry|:exit] [FETCHARGS] : Probe on > + list/wildcard > t[:[GRP2/][EVENT2]] TRACEPOINT [FETCHARGS] : Probe on tracepoint > > GRP1 : Group name for fprobe. If omitted, use "fprobes" for it. > GRP2 : Group name for tprobe. If omitted, use "tracepoints" for it. > EVENT1 : Event name for fprobe. If omitted, the event name is > - "SYM__entry" or "SYM__exit". > + - For a single literal symbol, the event name is > + "SYM__entry" or "SYM__exit". > + - For a *list or any wildcard*, an explicit [GRP1/][EVENT1] is > + required. > EVENT2 : Event name for tprobe. If omitted, the event name is > the same as "TRACEPOINT", but if the "TRACEPOINT" starts > with a digit character, "_TRACEPOINT" is used. > @@ -40,6 +45,13 @@ Synopsis of fprobe-events > can be probed simultaneously, or 0 for the default value > as defined in Documentation/trace/fprobe.rst > > + SYM : Function name or comma-separated list of symbols. > + - SYM prefixed with "!" are exclusions. > + - ":entry" suffix means it probes entry of given symbols > + (default) > + - ":exit" suffix means it probes exit of given symbols. > + - "%return" suffix means it probes exit of SYM (single > + symbol). > FETCHARGS : Arguments. Each probe can have up to 128 args. > ARG : Fetch "ARG" function argument using BTF (only for function > entry or tracepoint.) (\*1)
Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
---
tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
index 45e57c6f487d..79392e268929 100644
--- a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
+++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
@@ -1,7 +1,7 @@
#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
# description: Fprobe event list syntax and :entry/:exit suffixes
-# requires: dynamic_events "f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]":README
+# requires: dynamic_events "f[:[<group>/][<event>]] <func-list>[:entry|:exit] [<args>]":README
# Setup symbols to test. These are common kernel functions.
PLACE=vfs_read
--
2.43.0On Wed, 14 Jan 2026 17:13:40 -0500 "Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote: -ENOCHANGELOG :-( -- Steve > Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com> > --- > tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc > index 45e57c6f487d..79392e268929 100644 > --- a/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc > +++ b/tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc > @@ -1,7 +1,7 @@ > #!/bin/sh > # SPDX-License-Identifier: GPL-2.0 > # description: Fprobe event list syntax and :entry/:exit suffixes > -# requires: dynamic_events "f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]":README > +# requires: dynamic_events "f[:[<group>/][<event>]] <func-list>[:entry|:exit] [<args>]":README > > # Setup symbols to test. These are common kernel functions. > PLACE=vfs_read
This series extends fprobe dynamic events to accept a comma-separated list of symbols and explicit/suffixes. Currently, fprobe only supports a single symbol (or wildcard) per event. This series allow users to specify a comma-separated list of symbols, including exclusions, and to select entry/exit explicitly using / Examples: - f:[GRP/][EVENT] func1,func2,func3 - f:[GRP/][EVENT] func1,!func2,func3 (exclude with '!') Logic changes: - Refactor parsing logic into parse_fprobe_spec() - Support comma-separated lists and '!' exclusions - Add / suffixes for explicit entry/exit selection - Preserve legacy single-symbol behavior (single symbols still accept %return) - Disable BTF-based signature lookup when list/wildcard is used, since one function signature cannot apply to multiple functions - Reject mixed legacy/new syntax where applicable (e.g. list + %return) - Update tracefs/README and fprobe documentation - Add ftrace selftests covering accepted list syntax cases *Patch order is adjusted: code first, then docs, then selftest Changes in v5: - Reordered patches (code->docs->selftests) as suggested - Addressed review feedback on README help text to show both legacy and list syntaxes - Added missing traceprobe error IDs used by the new validation and fixed parsing/bracing issues found by automated builds - Removed the dedicated list_mode field and infer list behavior from presence of filter/nofilter and keep struct trace_probe as the last member - Link to v4: https://lore.kernel.org/linux-trace-kernel/20251127151218.4763b25c751bb2aac4b1ee36@kernel.org/ I am not fully confident the runtime testing coverage that I did is sufficient across configs/architectures, so additional verification would be appreciated. Best regards, Ryan Chung Seokwoo Chung (Ryan) (3): tracing/fprobe: Support comma-separated symbols and :entry/:exit docs: tracing/fprobe: Document list filters and :entry/:exit selftests/ftrace: Add accept cases for fprobe list syntax Documentation/trace/fprobetrace.rst | 18 +++++-- kernel/trace/trace.c | 4 +- kernel/trace/trace_fprobe.c | 49 ++++++++++--------- kernel/trace/trace_probe.h | 2 + .../ftrace/test.d/dynevent/fprobe_list.tc | 2 +- 5 files changed, 47 insertions(+), 28 deletions(-) base-commit: f0c13b210e4366e03bd9e8967347b06b227e20a4 -- 2.43.0
On Wed, 26 Nov 2025 13:41:07 -0500
"Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote:
> Extend fprobe to support list-style filters and explicit entry/exit suffixes.
> Currentyl, fprobe only supports a single symbol (or wildcard) per event.
> This patch allows users to specify a comma-separated list of symbols.
>
> New Syntax:
> - f:[GRP/][EVENT] func1,func2,func3:entry
> - f:[GRP/][EVENT] func1,func2,func3:exit
Thanks for updating!
>
> Logic changes:
> - Refactor parsing logic into 'parse_fprobe_spec'
> - Support '!' prefix for exclusion
> - Disable BTF lookup ('ctx->funcname = NULL') when a list or wildcard is used,
> as a single function signature cannot apply to multiple functions.
> - Reject legacy '%return' suffix when used with lists or wildcards
> - Update tracefs/README
>
> Testing:
> Verified on x86_64 via QEMU. Checked registration of lists, exclusions, and
> explicit suffixes. Verified rejection of invalid syntax including trailing
> commas and mixed legacy/new syntax.
>
> Seokwoo Chung (Ryan) (3):
> docs: tracing/fprobe: Document list filters and :entry/:exit
> tracing/fprobe: Support comma-separated symbols and :entry/:exit
For the next time, please add docs patch after code change because of bisect.
(Or, include the document update into code update.)
> selftests/ftrace: Add accept cases for fprobe list syntax
Testing after code is good. :)
Thank you,
>
> Changes in v4:
> - Added validation to reject trailing commas (empty tokens) in symbol lists
> - Added vaildation to reject mixed of list syntax with %return suffix
> - Refactored parse_fprobe_spec to user __free(kfree) for automatic memory
> cleanup
> - Removed the now-unused parse_symbol_and_return function to avoid compiler
> warnings.
> - Tigtened %return detection to ensure it only matches as a strict suffix, not a
> substring
> - Link to v3: https://lore.kernel.org/lkml/20250904103219.f4937968362bfff1ecd3f004@kernel.org/
>
> Documentation/trace/fprobetrace.rst | 17 +-
> kernel/trace/trace.c | 3 +-
> kernel/trace/trace_fprobe.c | 209 ++++++++++++++----
> .../ftrace/test.d/dynevent/fprobe_list.tc | 92 ++++++++
> 4 files changed, 269 insertions(+), 52 deletions(-)
> create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/fprobe_list.tc
>
> --
> 2.43.0
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
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