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[PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit

Seokwoo Chung (Ryan) posted 3 patches 5 days, 3 hours ago
[PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
Posted by Seokwoo Chung (Ryan) 5 days, 3 hours ago 
- Update DEFINE_FREE to use standard __free()
- Extend fprobe to support multiple symbols per event. Add parsing logic for
  lists, ! exclusions, and explicit suffixes. Update tracefs/README to reflect
  the new syntax

Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
---
 kernel/trace/trace.c        |   3 +-
 kernel/trace/trace_fprobe.c | 209 +++++++++++++++++++++++++++---------
 2 files changed, 163 insertions(+), 49 deletions(-)

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index d1e527cf2aae..e0b77268a702 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5518,7 +5518,8 @@ static const char readme_msg[] =
 	"\t           r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
 #endif
 #ifdef CONFIG_FPROBE_EVENTS
-	"\t           f[:[<group>/][<event>]] <func-name>[%return] [<args>]\n"
+	"\t           f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]\n"
+	"\t		(single symbols still accept %return)\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 8001dbf16891..6307d7d7dd9c 100644
--- a/kernel/trace/trace_fprobe.c
+++ b/kernel/trace/trace_fprobe.c
@@ -187,11 +187,14 @@ 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;
 	bool			tprobe;
 	struct tracepoint_user	*tuser;
-	struct trace_probe	tp;
 };
 
 static bool is_trace_fprobe(struct dyn_event *ev)
@@ -559,6 +562,8 @@ static void free_trace_fprobe(struct trace_fprobe *tf)
 		trace_probe_cleanup(&tf->tp);
 		if (tf->tuser)
 			tracepoint_user_put(tf->tuser);
+		kfree(tf->filter);
+		kfree(tf->nofilter);
 		kfree(tf->symbol);
 		kfree(tf);
 	}
@@ -838,7 +843,12 @@ static int __register_trace_fprobe(struct trace_fprobe *tf)
 	if (trace_fprobe_is_tracepoint(tf))
 		return __regsiter_tracepoint_fprobe(tf);
 
-	/* TODO: handle filter, nofilter or symbol list */
+	/* Registration path:
+	 * - list_mode: pass filter/nofilter
+	 * - single: pass symbol only (legacy)
+	 */
+	if (tf->list_mode)
+		return register_fprobe(&tf->fp, tf->filter, tf->nofilter);
 	return register_fprobe(&tf->fp, tf->symbol, NULL);
 }
 
@@ -1154,60 +1164,119 @@ static struct notifier_block tprobe_event_module_nb = {
 };
 #endif /* CONFIG_MODULES */
 
-static int parse_symbol_and_return(int argc, const char *argv[],
-				   char **symbol, bool *is_return,
-				   bool is_tracepoint)
+static bool has_wildcard(const char *s)
 {
-	char *tmp = strchr(argv[1], '%');
-	int i;
+	return s && (strchr(s, '*') || strchr(s, '?'));
+}
 
-	if (tmp) {
-		int len = tmp - argv[1];
+static int parse_fprobe_spec(const char *in, bool is_tracepoint,
+		char **base, bool *is_return, bool *list_mode,
+		char **filter, char **nofilter)
+{
+	char *work __free(kfree) = NULL;
+	char *b __free(kfree) = NULL;
+	char *f __free(kfree) = NULL;
+	char *nf __free(kfree) = NULL;
+	bool legacy_ret = false;
+	bool list = false;
+	const char *p;
+	int ret = 0;
 
-		if (!is_tracepoint && !strcmp(tmp, "%return")) {
-			*is_return = true;
-		} else {
-			trace_probe_log_err(len, BAD_ADDR_SUFFIX);
-			return -EINVAL;
-		}
-		*symbol = kmemdup_nul(argv[1], len, GFP_KERNEL);
-	} else
-		*symbol = kstrdup(argv[1], GFP_KERNEL);
-	if (!*symbol)
-		return -ENOMEM;
+	if (!in || !base || !is_return || !list_mode || !filter || !nofilter)
+		return -EINVAL;
 
-	if (*is_return)
-		return 0;
+	*base = NULL; *filter = NULL; *nofilter = NULL;
+	*is_return = false; *list_mode = false;
 
 	if (is_tracepoint) {
-		tmp = *symbol;
-		while (*tmp && (isalnum(*tmp) || *tmp == '_'))
-			tmp++;
-		if (*tmp) {
-			/* find a wrong character. */
-			trace_probe_log_err(tmp - *symbol, BAD_TP_NAME);
-			kfree(*symbol);
-			*symbol = NULL;
+		if (strchr(in, ',') || strchr(in, ':'))
 			return -EINVAL;
-		}
+		if (strstr(in, "%return"))
+			return -EINVAL;
+		for (p = in; *p; p++)
+			if (!isalnum(*p) && *p != '_')
+				return -EINVAL;
+		b = kstrdup(in, GFP_KERNEL);
+		if (!b)
+			return -ENOMEM;
+		*base = no_free_ptr(b);
+		return 0;
 	}
 
-	/* If there is $retval, this should be a return fprobe. */
-	for (i = 2; i < argc; i++) {
-		tmp = strstr(argv[i], "$retval");
-		if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') {
-			if (is_tracepoint) {
-				trace_probe_log_set_index(i);
-				trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE);
-				kfree(*symbol);
-				*symbol = NULL;
+	work = kstrdup(in, GFP_KERNEL);
+	if (!work)
+		return -ENOMEM;
+
+	p = strstr(work, "%return");
+	if (p && p[7] == '\0') {
+		*is_return = true;
+		legacy_ret = true;
+		*(char *)p = '\0';
+	} else {
+		/*
+		 * If "symbol:entry" or "symbol:exit" is given, it is new
+		 * style probe.
+		 */
+		p = strrchr(work, ':');
+		if (p) {
+			if (!strcmp(p, ":exit")) {
+				*is_return = true;
+				*(char *)p = '\0';
+			} else if (!strcmp(p, ":entry")) {
+				*(char *)p = '\0';
+			} else {
 				return -EINVAL;
 			}
-			*is_return = true;
-			break;
 		}
 	}
-	return 0;
+
+	list = !!strchr(work, ',');
+	
+	if (list && legacy_ret) {
+		return -EINVAL;
+	}
+
+	if (legacy_ret)
+		*is_return = true;
+
+	b = kstrdup(work, GFP_KERNEL);
+	if (!b)
+		return -ENOMEM;
+
+	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);
+		if (!f || !nf)
+			return -ENOMEM;
+
+		while ((tok = strsep(&tmp, ",")) != NULL) {
+			char *dst;
+			bool neg = (*tok == '!');
+
+			if (*tok == '\0') {
+				trace_probe_log_err(tmp - b - 1, BAD_TP_NAME);
+				return -EINVAL;
+
+			if (neg)
+				tok++;
+			dst = neg ? nf : f;
+			if (dst[0] != '\0')
+				strcat(dst, ",");
+			strcat(dst, tok);
+		}
+		*list_mode = true;
+	}
+
+	*base = no_free_ptr(b);
+	*filter = no_free_ptr(f);
+	*nofilter = no_free_ptr(nf);
+
+	return ret;
 }
 
 static int trace_fprobe_create_internal(int argc, const char *argv[],
@@ -1241,6 +1310,8 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
 	const char *event = NULL, *group = FPROBE_EVENT_SYSTEM;
 	struct module *mod __free(module_put) = NULL;
 	const char **new_argv __free(kfree) = NULL;
+	char *parsed_nofilter __free(kfree) = NULL;
+	char *parsed_filter __free(kfree) = NULL;
 	char *symbol __free(kfree) = NULL;
 	char *ebuf __free(kfree) = NULL;
 	char *gbuf __free(kfree) = NULL;
@@ -1249,6 +1320,7 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
 	char *dbuf __free(kfree) = NULL;
 	int i, new_argc = 0, ret = 0;
 	bool is_tracepoint = false;
+	bool list_mode = false;
 	bool is_return = false;
 
 	if ((argv[0][0] != 'f' && argv[0][0] != 't') || argc < 2)
@@ -1270,11 +1342,26 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
 
 	trace_probe_log_set_index(1);
 
-	/* a symbol(or tracepoint) must be specified */
-	ret = parse_symbol_and_return(argc, argv, &symbol, &is_return, is_tracepoint);
+	/* Parse spec early (single vs list, suffix, base symbol) */
+	ret = parse_fprobe_spec(argv[1], is_tracepoint, &symbol, &is_return,
+			&list_mode, &parsed_filter, &parsed_nofilter);
 	if (ret < 0)
 		return -EINVAL;
 
+	for (i = 2; i < argc; i++) {
+		char *tmp = strstr(argv[i], "$retval");
+
+		if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') {
+			if (is_tracepoint) {
+				trace_probe_log_set_index(i);
+				trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE);
+				return -EINVAL;
+			}
+			is_return = true;
+			break;
+		}
+	}
+
 	trace_probe_log_set_index(0);
 	if (event) {
 		gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
@@ -1287,6 +1374,15 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
 	}
 
 	if (!event) {
+		/*
+		 * Event name rules:
+		 * - For list/wildcard: require explicit [GROUP/]EVENT
+		 * - For single literal: autogenerate symbol__entry/symbol__exit
+		 */
+		if (list_mode || has_wildcard(symbol)) {
+			trace_probe_log_err(0, NO_GROUP_NAME);
+			return -EINVAL;
+		}
 		ebuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
 		if (!ebuf)
 			return -ENOMEM;
@@ -1322,7 +1418,8 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
 							NULL, NULL, NULL, sbuf);
 		}
 	}
-	if (!ctx->funcname)
+
+	if (!list_mode && !has_wildcard(symbol) && !is_tracepoint)
 		ctx->funcname = symbol;
 
 	abuf = kmalloc(MAX_BTF_ARGS_LEN, GFP_KERNEL);
@@ -1356,6 +1453,21 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
 		return ret;
 	}
 
+	/* 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;
+		}
+	}
+
 	/* parse arguments */
 	for (i = 0; i < argc; i++) {
 		trace_probe_log_set_index(i + 2);
@@ -1442,8 +1554,9 @@ static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
 	seq_printf(m, ":%s/%s", trace_probe_group_name(&tf->tp),
 				trace_probe_name(&tf->tp));
 
-	seq_printf(m, " %s%s", trace_fprobe_symbol(tf),
-			       trace_fprobe_is_return(tf) ? "%return" : "");
+	seq_printf(m, " %s", trace_fprobe_symbol(tf));
+	if (!trace_fprobe_is_tracepoint(tf) && trace_fprobe_is_return(tf))
+		seq_puts(m, ":exit");
 
 	for (i = 0; i < tf->tp.nr_args; i++)
 		seq_printf(m, " %s=%s", tf->tp.args[i].name, tf->tp.args[i].comm);
-- 
2.43.0
Re: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
Posted by kernel test robot 4 days, 7 hours ago 
Hi Seokwoo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on trace/for-next]
[also build test WARNING on linus/master v6.18-rc7 next-20251127]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Seokwoo-Chung-Ryan/docs-tracing-fprobe-Document-list-filters-and-entry-exit/20251127-024245
base:   https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link:    https://lore.kernel.org/r/20251126184110.72241-3-seokwoo.chung130%40gmail.com
patch subject: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
config: x86_64-randconfig-003-20251127 (https://download.01.org/0day-ci/archive/20251127/202511272241.s6tUpIgv-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251127/202511272241.s6tUpIgv-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511272241.s6tUpIgv-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/trace/trace_fprobe.c: In function 'parse_fprobe_spec':
   kernel/trace/trace_fprobe.c:1282:12: error: invalid storage class for function 'trace_fprobe_create_internal'
    1282 | static int trace_fprobe_create_internal(int argc, const char *argv[],
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1513:12: error: invalid storage class for function 'trace_fprobe_create_cb'
    1513 | static int trace_fprobe_create_cb(int argc, const char *argv[])
         |            ^~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1530:12: error: invalid storage class for function 'trace_fprobe_create'
    1530 | static int trace_fprobe_create(const char *raw_command)
         |            ^~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1535:12: error: invalid storage class for function 'trace_fprobe_release'
    1535 | static int trace_fprobe_release(struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1545:12: error: invalid storage class for function 'trace_fprobe_show'
    1545 | static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1572:12: error: invalid storage class for function 'enable_trace_fprobe'
    1572 | static int enable_trace_fprobe(struct trace_event_call *call,
         |            ^~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1608:12: error: invalid storage class for function 'disable_trace_fprobe'
    1608 | static int disable_trace_fprobe(struct trace_event_call *call,
         |            ^~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1653:12: error: invalid storage class for function 'fprobe_register'
    1653 | static int fprobe_register(struct trace_event_call *event,
         |            ^~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1683:19: error: invalid storage class for function 'init_fprobe_trace_early'
    1683 | static __init int init_fprobe_trace_early(void)
         |                   ^~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/fprobe.h:6,
                    from kernel/trace/trace_fprobe.c:8:
   include/linux/compiler.h:286:52: error: initializer element is not constant
     286 |         __UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)(uintptr_t)&sym;
         |                                                    ^
   include/linux/compiler.h:289:9: note: in expansion of macro '___ADDRESSABLE'
     289 |         ___ADDRESSABLE(sym, __section(".discard.addressable"))
         |         ^~~~~~~~~~~~~~
   include/linux/init.h:250:9: note: in expansion of macro '__ADDRESSABLE'
     250 |         __ADDRESSABLE(fn)
         |         ^~~~~~~~~~~~~
   include/linux/init.h:255:9: note: in expansion of macro '__define_initcall_stub'
     255 |         __define_initcall_stub(__stub, fn)                      \
         |         ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/init.h:268:9: note: in expansion of macro '____define_initcall'
     268 |         ____define_initcall(fn,                                 \
         |         ^~~~~~~~~~~~~~~~~~~
   include/linux/init.h:274:9: note: in expansion of macro '__unique_initcall'
     274 |         __unique_initcall(fn, id, __sec, __initcall_id(fn))
         |         ^~~~~~~~~~~~~~~~~
   include/linux/init.h:276:35: note: in expansion of macro '___define_initcall'
     276 | #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id)
         |                                   ^~~~~~~~~~~~~~~~~~
   include/linux/init.h:294:41: note: in expansion of macro '__define_initcall'
     294 | #define core_initcall(fn)               __define_initcall(fn, 1)
         |                                         ^~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1702:1: note: in expansion of macro 'core_initcall'
    1702 | core_initcall(init_fprobe_trace_early);
         | ^~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1702:1: error: expected declaration or statement at end of input
   kernel/trace/trace_fprobe.c: At top level:
>> kernel/trace/trace_fprobe.c:28:12: warning: 'trace_fprobe_create' used but never defined
      28 | static int trace_fprobe_create(const char *raw_command);
         |            ^~~~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:29:12: warning: 'trace_fprobe_show' used but never defined
      29 | static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev);
         |            ^~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:30:12: warning: 'trace_fprobe_release' used but never defined
      30 | static int trace_fprobe_release(struct dyn_event *ev);
         |            ^~~~~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:741:12: warning: 'fprobe_register' used but never defined
     741 | static int fprobe_register(struct trace_event_call *event,
         |            ^~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1653:12: warning: 'fprobe_register' defined but not used [-Wunused-function]
    1653 | static int fprobe_register(struct trace_event_call *event,
         |            ^~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1545:12: warning: 'trace_fprobe_show' defined but not used [-Wunused-function]
    1545 | static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1535:12: warning: 'trace_fprobe_release' defined but not used [-Wunused-function]
    1535 | static int trace_fprobe_release(struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1530:12: warning: 'trace_fprobe_create' defined but not used [-Wunused-function]
    1530 | static int trace_fprobe_create(const char *raw_command)
         |            ^~~~~~~~~~~~~~~~~~~


vim +/trace_fprobe_create +28 kernel/trace/trace_fprobe.c

334e5519c375701 Masami Hiramatsu (Google  2023-06-06  27) 
334e5519c375701 Masami Hiramatsu (Google  2023-06-06 @28) static int trace_fprobe_create(const char *raw_command);
334e5519c375701 Masami Hiramatsu (Google  2023-06-06 @29) static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev);
334e5519c375701 Masami Hiramatsu (Google  2023-06-06 @30) static int trace_fprobe_release(struct dyn_event *ev);
334e5519c375701 Masami Hiramatsu (Google  2023-06-06  31) static bool trace_fprobe_is_busy(struct dyn_event *ev);
334e5519c375701 Masami Hiramatsu (Google  2023-06-06  32) static bool trace_fprobe_match(const char *system, const char *event,
334e5519c375701 Masami Hiramatsu (Google  2023-06-06  33) 			int argc, const char **argv, struct dyn_event *ev);
334e5519c375701 Masami Hiramatsu (Google  2023-06-06  34) 

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
Posted by kernel test robot 4 days, 7 hours ago 
Hi Seokwoo,

kernel test robot noticed the following build errors:

[auto build test ERROR on trace/for-next]
[also build test ERROR on linus/master v6.18-rc7 next-20251127]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Seokwoo-Chung-Ryan/docs-tracing-fprobe-Document-list-filters-and-entry-exit/20251127-024245
base:   https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link:    https://lore.kernel.org/r/20251126184110.72241-3-seokwoo.chung130%40gmail.com
patch subject: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
config: x86_64-randconfig-001-20251127 (https://download.01.org/0day-ci/archive/20251127/202511272254.BX8oUzwu-lkp@intel.com/config)
compiler: clang version 20.1.8 (https://github.com/llvm/llvm-project 87f0227cb60147a26a1eeb4fb06e3b505e9c7261)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251127/202511272254.BX8oUzwu-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511272254.BX8oUzwu-lkp@intel.com/

All errors (new ones prefixed by >>):

>> kernel/trace/trace_fprobe.c:1284:1: error: function definition is not allowed here
    1284 | {
         | ^
   kernel/trace/trace_fprobe.c:1514:1: error: function definition is not allowed here
    1514 | {
         | ^
   kernel/trace/trace_fprobe.c:1531:1: error: function definition is not allowed here
    1531 | {
         | ^
   kernel/trace/trace_fprobe.c:1536:1: error: function definition is not allowed here
    1536 | {
         | ^
   kernel/trace/trace_fprobe.c:1546:1: error: function definition is not allowed here
    1546 | {
         | ^
   kernel/trace/trace_fprobe.c:1574:1: error: function definition is not allowed here
    1574 | {
         | ^
   kernel/trace/trace_fprobe.c:1610:1: error: function definition is not allowed here
    1610 | {
         | ^
   kernel/trace/trace_fprobe.c:1655:1: error: function definition is not allowed here
    1655 | {
         | ^
   kernel/trace/trace_fprobe.c:1684:1: error: function definition is not allowed here
    1684 | {
         | ^
>> kernel/trace/trace_fprobe.c:1702:15: error: use of undeclared identifier 'init_fprobe_trace_early'
    1702 | core_initcall(init_fprobe_trace_early);
         |               ^
>> kernel/trace/trace_fprobe.c:1702:15: error: use of undeclared identifier 'init_fprobe_trace_early'
>> kernel/trace/trace_fprobe.c:1702:40: error: expected '}'
    1702 | core_initcall(init_fprobe_trace_early);
         |                                        ^
   kernel/trace/trace_fprobe.c:1175:1: note: to match this '{'
    1175 | {
         | ^
   12 errors generated.


vim +1284 kernel/trace/trace_fprobe.c

08c9306fc2e32b Masami Hiramatsu (Google  2023-08-23  1281) 
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1282) static int trace_fprobe_create_internal(int argc, const char *argv[],
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1283) 					struct traceprobe_parse_context *ctx)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06 @1284) {
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1285) 	/*
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1286) 	 * Argument syntax:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1287) 	 *  - Add fentry probe:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1288) 	 *      f[:[GRP/][EVENT]] [MOD:]KSYM [FETCHARGS]
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1289) 	 *  - Add fexit probe:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1290) 	 *      f[N][:[GRP/][EVENT]] [MOD:]KSYM%return [FETCHARGS]
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1291) 	 *  - Add tracepoint probe:
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1292) 	 *      t[:[GRP/][EVENT]] TRACEPOINT [FETCHARGS]
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1293) 	 *
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1294) 	 * Fetch args:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1295) 	 *  $retval	: fetch return value
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1296) 	 *  $stack	: fetch stack address
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1297) 	 *  $stackN	: fetch Nth entry of stack (N:0-)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1298) 	 *  $argN	: fetch Nth argument (N:1-)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1299) 	 *  $comm       : fetch current task comm
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1300) 	 *  @ADDR	: fetch memory at ADDR (ADDR should be in kernel)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1301) 	 *  @SYM[+|-offs] : fetch memory at SYM +|- offs (SYM is a data symbol)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1302) 	 * Dereferencing memory fetch:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1303) 	 *  +|-offs(ARG) : fetch memory at ARG +|- offs address.
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1304) 	 * Alias name of args:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1305) 	 *  NAME=FETCHARG : set NAME as alias of FETCHARG.
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1306) 	 * Type of args:
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1307) 	 *  FETCHARG:TYPE : use TYPE instead of unsigned long.
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1308) 	 */
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1309) 	struct trace_fprobe *tf __free(free_trace_fprobe) = NULL;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1310) 	const char *event = NULL, *group = FPROBE_EVENT_SYSTEM;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1311) 	struct module *mod __free(module_put) = NULL;
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1312) 	const char **new_argv __free(kfree) = NULL;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1313) 	char *parsed_nofilter __free(kfree) = NULL;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1314) 	char *parsed_filter __free(kfree) = NULL;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1315) 	char *symbol __free(kfree) = NULL;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1316) 	char *ebuf __free(kfree) = NULL;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1317) 	char *gbuf __free(kfree) = NULL;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1318) 	char *sbuf __free(kfree) = NULL;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1319) 	char *abuf __free(kfree) = NULL;
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1320) 	char *dbuf __free(kfree) = NULL;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1321) 	int i, new_argc = 0, ret = 0;
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1322) 	bool is_tracepoint = false;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1323) 	bool list_mode = false;
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1324) 	bool is_return = false;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1325) 
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1326) 	if ((argv[0][0] != 'f' && argv[0][0] != 't') || argc < 2)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1327) 		return -ECANCELED;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1328) 
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1329) 	if (argv[0][0] == 't') {
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1330) 		is_tracepoint = true;
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1331) 		group = TRACEPOINT_EVENT_SYSTEM;
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1332) 	}
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1333) 
a2224559cbba1d Masami Hiramatsu (Google  2024-12-26  1334) 	if (argv[0][1] != '\0') {
a2224559cbba1d Masami Hiramatsu (Google  2024-12-26  1335) 		if (argv[0][1] != ':') {
a2224559cbba1d Masami Hiramatsu (Google  2024-12-26  1336) 			trace_probe_log_set_index(0);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1337) 			trace_probe_log_err(1, BAD_MAXACT);
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1338) 			return -EINVAL;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1339) 		}
a2224559cbba1d Masami Hiramatsu (Google  2024-12-26  1340) 		event = &argv[0][2];
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1341) 	}
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1342) 
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1343) 	trace_probe_log_set_index(1);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1344) 
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1345) 	/* Parse spec early (single vs list, suffix, base symbol) */
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1346) 	ret = parse_fprobe_spec(argv[1], is_tracepoint, &symbol, &is_return,
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1347) 			&list_mode, &parsed_filter, &parsed_nofilter);
08c9306fc2e32b Masami Hiramatsu (Google  2023-08-23  1348) 	if (ret < 0)
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1349) 		return -EINVAL;
08c9306fc2e32b Masami Hiramatsu (Google  2023-08-23  1350) 
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1351) 	for (i = 2; i < argc; i++) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1352) 		char *tmp = strstr(argv[i], "$retval");
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1353) 
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1354) 		if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1355) 			if (is_tracepoint) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1356) 				trace_probe_log_set_index(i);
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1357) 				trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE);
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1358) 				return -EINVAL;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1359) 			}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1360) 			is_return = true;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1361) 			break;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1362) 		}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1363) 	}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1364) 
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1365) 	trace_probe_log_set_index(0);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1366) 	if (event) {
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1367) 		gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1368) 		if (!gbuf)
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1369) 			return -ENOMEM;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1370) 		ret = traceprobe_parse_event_name(&event, &group, gbuf,
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1371) 						  event - argv[0]);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1372) 		if (ret)
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1373) 			return -EINVAL;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1374) 	}
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1375) 
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1376) 	if (!event) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1377) 		/*
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1378) 		 * Event name rules:
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1379) 		 * - For list/wildcard: require explicit [GROUP/]EVENT
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1380) 		 * - For single literal: autogenerate symbol__entry/symbol__exit
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1381) 		 */
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1382) 		if (list_mode || has_wildcard(symbol)) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1383) 			trace_probe_log_err(0, NO_GROUP_NAME);
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1384) 			return -EINVAL;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1385) 		}
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1386) 		ebuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1387) 		if (!ebuf)
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1388) 			return -ENOMEM;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1389) 		/* Make a new event name */
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1390) 		if (is_tracepoint)
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1391) 			snprintf(ebuf, MAX_EVENT_NAME_LEN, "%s%s",
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1392) 				 isdigit(*symbol) ? "_" : "", symbol);
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1393) 		else
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1394) 			snprintf(ebuf, MAX_EVENT_NAME_LEN, "%s__%s", symbol,
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1395) 				 is_return ? "exit" : "entry");
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1396) 		sanitize_event_name(ebuf);
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1397) 		event = ebuf;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1398) 	}
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1399) 
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1400) 	if (is_return)
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1401) 		ctx->flags |= TPARG_FL_RETURN;
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1402) 	else
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1403) 		ctx->flags |= TPARG_FL_FENTRY;
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1404) 
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1405) 	ctx->funcname = NULL;
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1406) 	if (is_tracepoint) {
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1407) 		/* Get tracepoint and lock its module until the end of the registration. */
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1408) 		struct tracepoint *tpoint;
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1409) 
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1410) 		ctx->flags |= TPARG_FL_TPOINT;
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1411) 		mod = NULL;
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1412) 		tpoint = find_tracepoint(symbol, &mod);
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1413) 		if (tpoint) {
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1414) 			sbuf = kmalloc(KSYM_NAME_LEN, GFP_KERNEL);
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1415) 			if (!sbuf)
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1416) 				return -ENOMEM;
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1417) 			ctx->funcname = kallsyms_lookup((unsigned long)tpoint->probestub,
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1418) 							NULL, NULL, NULL, sbuf);
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1419) 		}
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1420) 	}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1421) 
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1422) 	if (!list_mode && !has_wildcard(symbol) && !is_tracepoint)
e3d6e1b9a34c74 Masami Hiramatsu (Google  2025-04-01  1423) 		ctx->funcname = symbol;
b576e09701c7d0 Masami Hiramatsu (Google  2023-06-06  1424) 
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1425) 	abuf = kmalloc(MAX_BTF_ARGS_LEN, GFP_KERNEL);
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1426) 	if (!abuf)
d643eaa7082dc3 Masami Hiramatsu (Google  2025-07-23  1427) 		return -ENOMEM;
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1428) 	argc -= 2; argv += 2;
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1429) 	new_argv = traceprobe_expand_meta_args(argc, argv, &new_argc,
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1430) 					       abuf, MAX_BTF_ARGS_LEN, ctx);
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1431) 	if (IS_ERR(new_argv))
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1432) 		return PTR_ERR(new_argv);
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1433) 	if (new_argv) {
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1434) 		argc = new_argc;
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1435) 		argv = new_argv;
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1436) 	}
57faaa04804ccb Masami Hiramatsu (Google  2025-03-27  1437) 	if (argc > MAX_TRACE_ARGS) {
57faaa04804ccb Masami Hiramatsu (Google  2025-03-27  1438) 		trace_probe_log_set_index(2);
57faaa04804ccb Masami Hiramatsu (Google  2025-03-27  1439) 		trace_probe_log_err(0, TOO_MANY_ARGS);
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1440) 		return -E2BIG;
57faaa04804ccb Masami Hiramatsu (Google  2025-03-27  1441) 	}
18b1e870a49671 Masami Hiramatsu (Google  2023-06-06  1442) 
d9b15224dd8ff8 Ye Bin                    2024-03-22  1443  	ret = traceprobe_expand_dentry_args(argc, argv, &dbuf);
d9b15224dd8ff8 Ye Bin                    2024-03-22  1444  	if (ret)
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1445) 		return ret;
d9b15224dd8ff8 Ye Bin                    2024-03-22  1446  
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1447) 	/* setup a probe */
2867495dea8632 Masami Hiramatsu (Google  2025-04-01  1448) 	tf = alloc_trace_fprobe(group, event, symbol, argc, is_return, is_tracepoint);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1449) 	if (IS_ERR(tf)) {
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1450) 		ret = PTR_ERR(tf);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1451) 		/* This must return -ENOMEM, else there is a bug */
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1452) 		WARN_ON_ONCE(ret != -ENOMEM);
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1453) 		return ret;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1454) 	}
e2d0d7b2f42dca Masami Hiramatsu (Google  2023-06-06  1455) 
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1456) 	/* carry list parsing result into tf */
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1457) 	if (!is_tracepoint) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1458) 		tf->list_mode = list_mode;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1459) 		if (parsed_filter) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1460) 			tf->filter = kstrdup(parsed_filter, GFP_KERNEL);
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1461) 			if (!tf->filter)
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1462) 				return -ENOMEM;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1463) 		}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1464) 		if (parsed_nofilter) {
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1465) 			tf->nofilter = kstrdup(parsed_nofilter, GFP_KERNEL);
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1466) 			if (!tf->nofilter)
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1467) 				return -ENOMEM;
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1468) 		}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1469) 	}
a90d508c939bee Seokwoo Chung (Ryan       2025-11-26  1470) 
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1471) 	/* parse arguments */
73f35080477e89 Mikel Rychliski           2024-09-30  1472  	for (i = 0; i < argc; i++) {
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1473) 		trace_probe_log_set_index(i + 2);
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1474) 		ctx->offset = 0;
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1475) 		ret = traceprobe_parse_probe_arg(&tf->tp, i, argv[i], ctx);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1476) 		if (ret)
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1477) 			return ret;	/* This can be -ENOMEM */
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1478) 	}
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1479) 
25f00e40ce7953 Masami Hiramatsu (Google  2024-03-04  1480) 	if (is_return && tf->tp.entry_arg) {
25f00e40ce7953 Masami Hiramatsu (Google  2024-03-04  1481) 		tf->fp.entry_handler = trace_fprobe_entry_handler;
25f00e40ce7953 Masami Hiramatsu (Google  2024-03-04  1482) 		tf->fp.entry_data_size = traceprobe_get_entry_data_size(&tf->tp);
db5e228611b118 Masami Hiramatsu (Google  2025-02-26  1483) 		if (ALIGN(tf->fp.entry_data_size, sizeof(long)) > MAX_FPROBE_DATA_SIZE) {
db5e228611b118 Masami Hiramatsu (Google  2025-02-26  1484) 			trace_probe_log_set_index(2);
db5e228611b118 Masami Hiramatsu (Google  2025-02-26  1485) 			trace_probe_log_err(0, TOO_MANY_EARGS);
db5e228611b118 Masami Hiramatsu (Google  2025-02-26  1486) 			return -E2BIG;
db5e228611b118 Masami Hiramatsu (Google  2025-02-26  1487) 		}
25f00e40ce7953 Masami Hiramatsu (Google  2024-03-04  1488) 	}
25f00e40ce7953 Masami Hiramatsu (Google  2024-03-04  1489) 
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1490) 	ret = traceprobe_set_print_fmt(&tf->tp,
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1491) 			is_return ? PROBE_PRINT_RETURN : PROBE_PRINT_NORMAL);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1492) 	if (ret < 0)
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1493) 		return ret;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1494) 
2db832ec9090d3 Masami Hiramatsu (Google  2025-04-01  1495) 	ret = register_trace_fprobe_event(tf);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1496) 	if (ret) {
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1497) 		trace_probe_log_set_index(1);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1498) 		if (ret == -EILSEQ)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1499) 			trace_probe_log_err(0, BAD_INSN_BNDRY);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1500) 		else if (ret == -ENOENT)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1501) 			trace_probe_log_err(0, BAD_PROBE_ADDR);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1502) 		else if (ret != -ENOMEM && ret != -EEXIST)
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1503) 			trace_probe_log_err(0, FAIL_REG_PROBE);
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1504) 		return -EINVAL;
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1505) 	}
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  1506) 
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1507) 	/* 'tf' is successfully registered. To avoid freeing, assign NULL. */
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1508) 	tf = NULL;
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1509) 
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1510) 	return 0;
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1511) }
8275637215bd3d Masami Hiramatsu (Google  2025-01-17  1512) 

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
Posted by kernel test robot 4 days, 10 hours ago 
Hi Seokwoo,

kernel test robot noticed the following build warnings:

[auto build test WARNING on trace/for-next]
[also build test WARNING on linus/master v6.18-rc7 next-20251127]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Seokwoo-Chung-Ryan/docs-tracing-fprobe-Document-list-filters-and-entry-exit/20251127-024245
base:   https://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace for-next
patch link:    https://lore.kernel.org/r/20251126184110.72241-3-seokwoo.chung130%40gmail.com
patch subject: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
config: x86_64-randconfig-003-20251127 (https://download.01.org/0day-ci/archive/20251127/202511271925.xuaUx8bB-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251127/202511271925.xuaUx8bB-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202511271925.xuaUx8bB-lkp@intel.com/

All warnings (new ones prefixed by >>):

   kernel/trace/trace_fprobe.c: In function 'parse_fprobe_spec':
   kernel/trace/trace_fprobe.c:1282:12: error: invalid storage class for function 'trace_fprobe_create_internal'
    1282 | static int trace_fprobe_create_internal(int argc, const char *argv[],
         |            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1513:12: error: invalid storage class for function 'trace_fprobe_create_cb'
    1513 | static int trace_fprobe_create_cb(int argc, const char *argv[])
         |            ^~~~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1530:12: error: invalid storage class for function 'trace_fprobe_create'
    1530 | static int trace_fprobe_create(const char *raw_command)
         |            ^~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1535:12: error: invalid storage class for function 'trace_fprobe_release'
    1535 | static int trace_fprobe_release(struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1545:12: error: invalid storage class for function 'trace_fprobe_show'
    1545 | static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1572:12: error: invalid storage class for function 'enable_trace_fprobe'
    1572 | static int enable_trace_fprobe(struct trace_event_call *call,
         |            ^~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1608:12: error: invalid storage class for function 'disable_trace_fprobe'
    1608 | static int disable_trace_fprobe(struct trace_event_call *call,
         |            ^~~~~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1653:12: error: invalid storage class for function 'fprobe_register'
    1653 | static int fprobe_register(struct trace_event_call *event,
         |            ^~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1683:19: error: invalid storage class for function 'init_fprobe_trace_early'
    1683 | static __init int init_fprobe_trace_early(void)
         |                   ^~~~~~~~~~~~~~~~~~~~~~~
   In file included from include/linux/fprobe.h:6,
                    from kernel/trace/trace_fprobe.c:8:
   include/linux/compiler.h:286:52: error: initializer element is not constant
     286 |         __UNIQUE_ID(__PASTE(__addressable_,sym)) = (void *)(uintptr_t)&sym;
         |                                                    ^
   include/linux/compiler.h:289:9: note: in expansion of macro '___ADDRESSABLE'
     289 |         ___ADDRESSABLE(sym, __section(".discard.addressable"))
         |         ^~~~~~~~~~~~~~
   include/linux/init.h:250:9: note: in expansion of macro '__ADDRESSABLE'
     250 |         __ADDRESSABLE(fn)
         |         ^~~~~~~~~~~~~
   include/linux/init.h:255:9: note: in expansion of macro '__define_initcall_stub'
     255 |         __define_initcall_stub(__stub, fn)                      \
         |         ^~~~~~~~~~~~~~~~~~~~~~
   include/linux/init.h:268:9: note: in expansion of macro '____define_initcall'
     268 |         ____define_initcall(fn,                                 \
         |         ^~~~~~~~~~~~~~~~~~~
   include/linux/init.h:274:9: note: in expansion of macro '__unique_initcall'
     274 |         __unique_initcall(fn, id, __sec, __initcall_id(fn))
         |         ^~~~~~~~~~~~~~~~~
   include/linux/init.h:276:35: note: in expansion of macro '___define_initcall'
     276 | #define __define_initcall(fn, id) ___define_initcall(fn, id, .initcall##id)
         |                                   ^~~~~~~~~~~~~~~~~~
   include/linux/init.h:294:41: note: in expansion of macro '__define_initcall'
     294 | #define core_initcall(fn)               __define_initcall(fn, 1)
         |                                         ^~~~~~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1702:1: note: in expansion of macro 'core_initcall'
    1702 | core_initcall(init_fprobe_trace_early);
         | ^~~~~~~~~~~~~
   kernel/trace/trace_fprobe.c:1702:1: error: expected declaration or statement at end of input
   kernel/trace/trace_fprobe.c: At top level:
>> kernel/trace/trace_fprobe.c:28:12: warning: 'trace_fprobe_create' used but never defined
      28 | static int trace_fprobe_create(const char *raw_command);
         |            ^~~~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:29:12: warning: 'trace_fprobe_show' used but never defined
      29 | static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev);
         |            ^~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:30:12: warning: 'trace_fprobe_release' used but never defined
      30 | static int trace_fprobe_release(struct dyn_event *ev);
         |            ^~~~~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:741:12: warning: 'fprobe_register' used but never defined
     741 | static int fprobe_register(struct trace_event_call *event,
         |            ^~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1653:12: warning: 'fprobe_register' defined but not used [-Wunused-function]
    1653 | static int fprobe_register(struct trace_event_call *event,
         |            ^~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1545:12: warning: 'trace_fprobe_show' defined but not used [-Wunused-function]
    1545 | static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1535:12: warning: 'trace_fprobe_release' defined but not used [-Wunused-function]
    1535 | static int trace_fprobe_release(struct dyn_event *ev)
         |            ^~~~~~~~~~~~~~~~~~~~
>> kernel/trace/trace_fprobe.c:1530:12: warning: 'trace_fprobe_create' defined but not used [-Wunused-function]
    1530 | static int trace_fprobe_create(const char *raw_command)
         |            ^~~~~~~~~~~~~~~~~~~


vim +/trace_fprobe_create +28 kernel/trace/trace_fprobe.c

334e5519c37570 Masami Hiramatsu (Google  2023-06-06  27) 
334e5519c37570 Masami Hiramatsu (Google  2023-06-06 @28) static int trace_fprobe_create(const char *raw_command);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06 @29) static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06 @30) static int trace_fprobe_release(struct dyn_event *ev);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  31) static bool trace_fprobe_is_busy(struct dyn_event *ev);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  32) static bool trace_fprobe_match(const char *system, const char *event,
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  33) 			int argc, const char **argv, struct dyn_event *ev);
334e5519c37570 Masami Hiramatsu (Google  2023-06-06  34) 

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki
Re: [PATCH v4 2/3] tracing/fprobe: Support comma-separated symbols and :entry/:exit
Posted by Masami Hiramatsu (Google) 4 days, 16 hours ago 
On Wed, 26 Nov 2025 13:41:09 -0500
"Seokwoo Chung (Ryan)" <seokwoo.chung130@gmail.com> wrote:

> - Update DEFINE_FREE to use standard __free()
> - Extend fprobe to support multiple symbols per event. Add parsing logic for
>   lists, ! exclusions, and explicit suffixes. Update tracefs/README to reflect
>   the new syntax
> 
> Signed-off-by: Seokwoo Chung (Ryan) <seokwoo.chung130@gmail.com>
> ---
>  kernel/trace/trace.c        |   3 +-
>  kernel/trace/trace_fprobe.c | 209 +++++++++++++++++++++++++++---------
>  2 files changed, 163 insertions(+), 49 deletions(-)
> 
> diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
> index d1e527cf2aae..e0b77268a702 100644
> --- a/kernel/trace/trace.c
> +++ b/kernel/trace/trace.c
> @@ -5518,7 +5518,8 @@ static const char readme_msg[] =
>  	"\t           r[maxactive][:[<group>/][<event>]] <place> [<args>]\n"
>  #endif
>  #ifdef CONFIG_FPROBE_EVENTS
> -	"\t           f[:[<group>/][<event>]] <func-name>[%return] [<args>]\n"
> +	"\t           f[:[<group>/][<event>]] <func-name>[:entry|:exit] [<args>]\n"
> +	"\t		(single symbols still accept %return)\n"

Hm, I would like to keep previous line. What about this (instead of 
adding a note line)?

	"\t           f[:[<group>/][<event>]] <func-name>[%return] [<args>]\n"
	"\t           f[:[<group>/][<event>]] <func-list>[:entry|:exit] [<args>]\n"

This shows both syntax exists clearly, and the new one accepts a list
of functions.

>  	"\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 8001dbf16891..6307d7d7dd9c 100644
> --- a/kernel/trace/trace_fprobe.c
> +++ b/kernel/trace/trace_fprobe.c
> @@ -187,11 +187,14 @@ DEFINE_FREE(tuser_put, struct tracepoint_user *,
>   */
>  struct trace_fprobe {
>  	struct dyn_event	devent;
> +	char			*filter;

Please do not sort the field alphabetically. It should be gathered by
semantics.

>  	struct fprobe		fp;
> +	bool			list_mode;

So filter should be here.

> +	char			*nofilter;
>  	const char		*symbol;
> +	struct trace_probe	tp;

Actually trace_probe must be the last field, because it has a variable
length array at the end.

>  	bool			tprobe;
>  	struct tracepoint_user	*tuser;
> -	struct trace_probe	tp;
>  };
>  
>  static bool is_trace_fprobe(struct dyn_event *ev)
> @@ -559,6 +562,8 @@ static void free_trace_fprobe(struct trace_fprobe *tf)
>  		trace_probe_cleanup(&tf->tp);
>  		if (tf->tuser)
>  			tracepoint_user_put(tf->tuser);
> +		kfree(tf->filter);
> +		kfree(tf->nofilter);
>  		kfree(tf->symbol);
>  		kfree(tf);
>  	}
> @@ -838,7 +843,12 @@ static int __register_trace_fprobe(struct trace_fprobe *tf)
>  	if (trace_fprobe_is_tracepoint(tf))
>  		return __regsiter_tracepoint_fprobe(tf);
>  
> -	/* TODO: handle filter, nofilter or symbol list */
> +	/* Registration path:
> +	 * - list_mode: pass filter/nofilter
> +	 * - single: pass symbol only (legacy)
> +	 */
> +	if (tf->list_mode)

If tf have filter or nofilter, that means it is list_mode, right?

	if (tf->filter || tf->nofilter)

is more straight. 

I think you can add

static bool trace_fprobe_has_list(struct trace_fprobe *tf)
{
	return tf->filter || tf->nofilter;
}

then we don't need tf::list_mode.

> +		return register_fprobe(&tf->fp, tf->filter, tf->nofilter);
>  	return register_fprobe(&tf->fp, tf->symbol, NULL);
>  }
>  
> @@ -1154,60 +1164,119 @@ static struct notifier_block tprobe_event_module_nb = {
>  };
>  #endif /* CONFIG_MODULES */
>  
> -static int parse_symbol_and_return(int argc, const char *argv[],
> -				   char **symbol, bool *is_return,
> -				   bool is_tracepoint)
> +static bool has_wildcard(const char *s)
>  {
> -	char *tmp = strchr(argv[1], '%');
> -	int i;
> +	return s && (strchr(s, '*') || strchr(s, '?'));
> +}
>  
> -	if (tmp) {
> -		int len = tmp - argv[1];
> +static int parse_fprobe_spec(const char *in, bool is_tracepoint,
> +		char **base, bool *is_return, bool *list_mode,
> +		char **filter, char **nofilter)
> +{
> +	char *work __free(kfree) = NULL;
> +	char *b __free(kfree) = NULL;
> +	char *f __free(kfree) = NULL;
> +	char *nf __free(kfree) = NULL;
> +	bool legacy_ret = false;
> +	bool list = false;
> +	const char *p;
> +	int ret = 0;
>  
> -		if (!is_tracepoint && !strcmp(tmp, "%return")) {
> -			*is_return = true;
> -		} else {
> -			trace_probe_log_err(len, BAD_ADDR_SUFFIX);
> -			return -EINVAL;
> -		}
> -		*symbol = kmemdup_nul(argv[1], len, GFP_KERNEL);
> -	} else
> -		*symbol = kstrdup(argv[1], GFP_KERNEL);
> -	if (!*symbol)
> -		return -ENOMEM;
> +	if (!in || !base || !is_return || !list_mode || !filter || !nofilter)
> +		return -EINVAL;
>  
> -	if (*is_return)
> -		return 0;
> +	*base = NULL; *filter = NULL; *nofilter = NULL;
> +	*is_return = false; *list_mode = false;
>  
>  	if (is_tracepoint) {
> -		tmp = *symbol;
> -		while (*tmp && (isalnum(*tmp) || *tmp == '_'))
> -			tmp++;
> -		if (*tmp) {
> -			/* find a wrong character. */
> -			trace_probe_log_err(tmp - *symbol, BAD_TP_NAME);
> -			kfree(*symbol);
> -			*symbol = NULL;
> +		if (strchr(in, ',') || strchr(in, ':'))
>  			return -EINVAL;
> -		}
> +		if (strstr(in, "%return"))
> +			return -EINVAL;

Please report some error before returning !ENOMEM error by
trace_probe_log_err().

> +		for (p = in; *p; p++)
> +			if (!isalnum(*p) && *p != '_')
> +				return -EINVAL;
> +		b = kstrdup(in, GFP_KERNEL);
> +		if (!b)
> +			return -ENOMEM;
> +		*base = no_free_ptr(b);
> +		return 0;
>  	}
>  
> -	/* If there is $retval, this should be a return fprobe. */
> -	for (i = 2; i < argc; i++) {
> -		tmp = strstr(argv[i], "$retval");
> -		if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') {
> -			if (is_tracepoint) {
> -				trace_probe_log_set_index(i);
> -				trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE);
> -				kfree(*symbol);
> -				*symbol = NULL;
> +	work = kstrdup(in, GFP_KERNEL);
> +	if (!work)
> +		return -ENOMEM;
> +
> +	p = strstr(work, "%return");
> +	if (p && p[7] == '\0') {
> +		*is_return = true;
> +		legacy_ret = true;
> +		*(char *)p = '\0';
> +	} else {
> +		/*
> +		 * If "symbol:entry" or "symbol:exit" is given, it is new
> +		 * style probe.
> +		 */
> +		p = strrchr(work, ':');
> +		if (p) {
> +			if (!strcmp(p, ":exit")) {
> +				*is_return = true;
> +				*(char *)p = '\0';
> +			} else if (!strcmp(p, ":entry")) {
> +				*(char *)p = '\0';
> +			} else {

trace_probe_log_err(p - work, BAD_LIST_SUFFIX);

>  				return -EINVAL;
>  			}
> -			*is_return = true;
> -			break;
>  		}
>  	}
> -	return 0;
> +
> +	list = !!strchr(work, ',');
> +	
> +	if (list && legacy_ret) {

trace_probe_log_err(<legacy_ret offset>, BAD_LEGACY_RET);

> +		return -EINVAL;
> +	}

Or, you don't need this brace for 1 line if block.

> +
> +	if (legacy_ret)
> +		*is_return = true;

You've already done this for legacy_ret.

> +
> +	b = kstrdup(work, GFP_KERNEL);
> +	if (!b)
> +		return -ENOMEM;
> +
> +	if (list) {
> +		char *tmp = b, *tok;
> +		size_t fsz, nfsz;
> +
> +		fsz = nfsz = strlen(b) + 1;

fsz and nfsz are used only once. Can be replaced with "strlen(b) + 1".

> +
> +		f = kzalloc(fsz, GFP_KERNEL);
> +		nf = kzalloc(nfsz, GFP_KERNEL);
> +		if (!f || !nf)
> +			return -ENOMEM;
> +
> +		while ((tok = strsep(&tmp, ",")) != NULL) {
> +			char *dst;
> +			bool neg = (*tok == '!');
> +
> +			if (*tok == '\0') {
> +				trace_probe_log_err(tmp - b - 1, BAD_TP_NAME);
> +				return -EINVAL;

Forgot a closing brace here. (did you build and test it?)

> +
> +			if (neg)
> +				tok++;
> +			dst = neg ? nf : f;
> +			if (dst[0] != '\0')
> +				strcat(dst, ",");
> +			strcat(dst, tok);
> +		}
> +		*list_mode = true;
> +	}
> +
> +	*base = no_free_ptr(b);
> +	*filter = no_free_ptr(f);
> +	*nofilter = no_free_ptr(nf);
> +
> +	return ret;
>  }
>  
>  static int trace_fprobe_create_internal(int argc, const char *argv[],
> @@ -1241,6 +1310,8 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>  	const char *event = NULL, *group = FPROBE_EVENT_SYSTEM;
>  	struct module *mod __free(module_put) = NULL;
>  	const char **new_argv __free(kfree) = NULL;
> +	char *parsed_nofilter __free(kfree) = NULL;
> +	char *parsed_filter __free(kfree) = NULL;
>  	char *symbol __free(kfree) = NULL;
>  	char *ebuf __free(kfree) = NULL;
>  	char *gbuf __free(kfree) = NULL;
> @@ -1249,6 +1320,7 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>  	char *dbuf __free(kfree) = NULL;
>  	int i, new_argc = 0, ret = 0;
>  	bool is_tracepoint = false;
> +	bool list_mode = false;
>  	bool is_return = false;
>  
>  	if ((argv[0][0] != 'f' && argv[0][0] != 't') || argc < 2)
> @@ -1270,11 +1342,26 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>  
>  	trace_probe_log_set_index(1);
>  
> -	/* a symbol(or tracepoint) must be specified */
> -	ret = parse_symbol_and_return(argc, argv, &symbol, &is_return, is_tracepoint);
> +	/* Parse spec early (single vs list, suffix, base symbol) */
> +	ret = parse_fprobe_spec(argv[1], is_tracepoint, &symbol, &is_return,
> +			&list_mode, &parsed_filter, &parsed_nofilter);
>  	if (ret < 0)
>  		return -EINVAL;
>  
> +	for (i = 2; i < argc; i++) {
> +		char *tmp = strstr(argv[i], "$retval");
> +
> +		if (tmp && !isalnum(tmp[7]) && tmp[7] != '_') {
> +			if (is_tracepoint) {
> +				trace_probe_log_set_index(i);
> +				trace_probe_log_err(tmp - argv[i], RETVAL_ON_PROBE);
> +				return -EINVAL;
> +			}
> +			is_return = true;
> +			break;
> +		}
> +	}
> +
>  	trace_probe_log_set_index(0);
>  	if (event) {
>  		gbuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
> @@ -1287,6 +1374,15 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>  	}
>  
>  	if (!event) {
> +		/*
> +		 * Event name rules:
> +		 * - For list/wildcard: require explicit [GROUP/]EVENT
> +		 * - For single literal: autogenerate symbol__entry/symbol__exit
> +		 */
> +		if (list_mode || has_wildcard(symbol)) {
> +			trace_probe_log_err(0, NO_GROUP_NAME);
> +			return -EINVAL;
> +		}
>  		ebuf = kmalloc(MAX_EVENT_NAME_LEN, GFP_KERNEL);
>  		if (!ebuf)
>  			return -ENOMEM;
> @@ -1322,7 +1418,8 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>  							NULL, NULL, NULL, sbuf);
>  		}
>  	}
> -	if (!ctx->funcname)
> +
> +	if (!list_mode && !has_wildcard(symbol) && !is_tracepoint)
>  		ctx->funcname = symbol;
>  
>  	abuf = kmalloc(MAX_BTF_ARGS_LEN, GFP_KERNEL);
> @@ -1356,6 +1453,21 @@ static int trace_fprobe_create_internal(int argc, const char *argv[],
>  		return ret;
>  	}
>  
> +	/* 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;
> +		}

You can just move it.

	tf->filter = no_free_ptr(parsed_filter);

> +		if (parsed_nofilter) {
> +			tf->nofilter = kstrdup(parsed_nofilter, GFP_KERNEL);
> +			if (!tf->nofilter)
> +				return -ENOMEM;
> +		}

Ditto.

> +	}
> +
>  	/* parse arguments */
>  	for (i = 0; i < argc; i++) {
>  		trace_probe_log_set_index(i + 2);
> @@ -1442,8 +1554,9 @@ static int trace_fprobe_show(struct seq_file *m, struct dyn_event *ev)
>  	seq_printf(m, ":%s/%s", trace_probe_group_name(&tf->tp),
>  				trace_probe_name(&tf->tp));
>  
> -	seq_printf(m, " %s%s", trace_fprobe_symbol(tf),
> -			       trace_fprobe_is_return(tf) ? "%return" : "");
> +	seq_printf(m, " %s", trace_fprobe_symbol(tf));
> +	if (!trace_fprobe_is_tracepoint(tf) && trace_fprobe_is_return(tf))
> +		seq_puts(m, ":exit");
>  
>  	for (i = 0; i < tf->tp.nr_args; i++)
>  		seq_printf(m, " %s=%s", tf->tp.args[i].name, tf->tp.args[i].comm);
> -- 
> 2.43.0
> 

Please build and run ftracetest under tools/testing/selftests.

Thank you,

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>

Patchew 2.1-devel-b67e4c2

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