[PATCH v9 30/39] dyndbg: control-parser: treat comma as a token separator

From: Jim Cromie via B4 Relay

Date: Tue Sep 08 2026 - 21:06:34 EST


From: Jim Cromie <jim.cromie@xxxxxxxxx>

Treat comma as a token terminator, just like a space. This allows a
user to avoid quoting hassles when spaces are otherwise needed:

:#> modprobe drm dyndbg=class,DRM_UT_CORE,+p\;class,DRM_UT_KMS,+p

Add corresponding Strategy 2 control-file fingerprinting checks to
verify the exact control-file state of kernel/params callsites after
commas-as-spaces, ignored-commas, and quoted-commas queries.

Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
Documentation/admin-guide/dynamic-debug-howto.rst | 4 +++-
lib/dynamic_debug.c | 17 +++++++++++++----
.../testing/selftests/dynamic_debug/dyndbg_selftest.sh | 4 ++--
3 files changed, 18 insertions(+), 7 deletions(-)

diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst
index 99bbae37d34e..fe86a9997ab5 100644
--- a/Documentation/admin-guide/dynamic-debug-howto.rst
+++ b/Documentation/admin-guide/dynamic-debug-howto.rst
@@ -78,11 +78,12 @@ Command Language Reference
==========================

At the basic lexical level, a command is a sequence of words separated
-by spaces or tabs. So these are all equivalent::
+by spaces, tabs, or commas. So these are all equivalent::

:#> ddcmd file svcsock.c line 1603 +p
:#> ddcmd "file svcsock.c line 1603 +p"
:#> ddcmd ' file svcsock.c line 1603 +p '
+ :#> ddcmd file,svcsock.c,line,1603,+p

Command submissions are bounded by a write() system call.
Multiple commands can be written together, separated by ``;`` or ``\n``::
@@ -176,6 +177,7 @@ module
module */main # any subsystem ending in main
module main # simple modname, selects same as above
module drm* # both drm, drm_kms_helper
+ module,sunrpc # with ',' as token separator

format
The given string is searched for in the dynamic debug format
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 15aba978d3c4..d28858acdc8f 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -322,6 +322,14 @@ static int ddebug_change(const struct ddebug_query *query, struct flag_settings
return nfound;
}

+static char *skip_spaces_and_commas(const char *str)
+{
+ str = skip_spaces(str);
+ while (*str == ',')
+ str = skip_spaces(++str);
+ return (char *)str;
+}
+
/*
* Split the buffer `buf' into space-separated words.
* Handles simple " and ' quoting, i.e. without nested,
@@ -335,8 +343,8 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
while (*buf) {
char *end;

- /* Skip leading whitespace */
- buf = skip_spaces(buf);
+ /* Skip leading whitespace and comma */
+ buf = skip_spaces_and_commas(buf);
if (!*buf)
break; /* oh, it was trailing whitespace */
if (*buf == '#')
@@ -352,7 +360,7 @@ static int ddebug_tokenize(char *buf, char *words[], int maxwords)
return -EINVAL; /* unclosed quote */
}
} else {
- for (end = buf; *end && !isspace(*end); end++)
+ for (end = buf; *end && !isspace(*end) && *end != ','; end++)
;
if (end == buf) {
pr_err("parse err after word:%d=%s\n", nwords,
@@ -627,7 +635,8 @@ static int ddebug_exec_queries(char *query, const char *modname)
if (split)
*split++ = '\0';

- query = skip_spaces(query);
+ query = skip_spaces_and_commas(query);
+
if (!query || !*query || *query == '#')
continue;

diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index 97588c9b07a7..89c9cfa23d2c 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -653,8 +653,8 @@ function GOLDEN_RECORDS {
#K= f2b4f24fece9c55f5a5d28323c2019f8 FT_basic_queries.5
#K= 8c2dd1164fbcefb721345ce62a864a37 FT_basic_queries.6
#K= 4542e1e5e7eadcbe8f90a9c934635618 FT_basic_queries.7
-#K= 3bcbdc30323082d6e961b5f0e269fff7 FT_test_classes.1
-#K= 5516e3d13cba7ea4197a7fb6c033887a FT_test_classes.2
+#K= 8146f6f983c3a76783c89b78b892ed48 FT_test_classes.1
+#K= a15ec4843acd721fbdfddc0b512c8032 FT_test_classes.2
#K= 20d4545f9753e677e72e3adf52527fd3 FT_test_classes.3
#K= 3a6afd41fadaaf70fad18f8a4632ffec FT_classmap_inheritance.1
#K= 6f1e347f0a7930814d2e54d589439465 FT_classmap_inheritance.2

--
2.55.0