Historically dynamic-debug gets its module names from KBUILD_MODNAME. This works well for loadable modules, as the module loader has always required them to have unique names, but for builtins it is basically kbasename(srcfile), which sadly gives us many modules named "main".
This makes the following ambiguous: bash-5.3# echo module main +m > /proc/dynamic_debug/control since it would affect 4 independent modules named main: bash-5.3# ddgrep =m init/main.c:1265 [main]initcall_blacklist =m "blacklisting initcall %s\n" kernel/power/main.c:49 [main]pm_restore_gfp_mask =m "GFP mask restored\n" kernel/module/main.c:2862 [main]move_module =m "\t0x%lx 0x%.8lx %s\n" drivers/base/power/main.c:149 [main]device_pm_add =m "Adding info for %s:%s\n" We can improve this by using KBUILD_MODFILE for dyndbg's modname in builtins, and KBUILD_MODNAME for loadables. The above control-file entries then become: init/main.c:1265 [init/main]initcall_blacklist ... kernel/power/main.c:49 [kernel/power/main]pm_restore_gfp_mask ... kernel/module/main.c:2862 [kernel/module/main]move_module ... drivers/base/power/main.c:149 [drivers/base/power/main]device_pm_add ... While this is a user visible change; [params] becomes [kernel/params], it is not a behavior change; we now match the query-module against the subsystem/module name or its kbasename (the simple-modname), which as before, matches all 4 modules. This allows queries to be specific when desired: "module init/main", while preserving the existing meaning of "module main" The deeper reason for this change is not obvious. If any builtin "main" module were to add a classmap, it would attach to all "main" modules. If 2 "main" modules defined separate classmaps, both modules would inadvertently share both classmaps. Since classmaps map classnames to 0..62, and independently defined classmaps are most likely to start at 0 (unless author is planning to share the 0..62 range with other classmaps), we have a setup for later reserved range conflicts. Having unique names prevents future conflicts. This solution isn't perfect: 1. it changes displayed [params] to [kernel/params] etc 2. its mostly redundant with "filename */main.*" 3. "module power", "module module", "module base/power" might be better but would break old queries. Adapt dynamic-debug selftest: 1- Add 'test_subsystem_module_queries' to verify path-based module matching. 2- Use dynamic counting with precise regexes to determine expectations. 3- Reorder tests to run slash-query verification immediately after basic tests. 4- Update basic_tests and comma_terminator_tests to use 'kernel/params' instead of 'params' to match new path-based names for built-ins. And adjust Documentation Signed-off-by: Jim Cromie <[email protected]> --- v4: use new match_wildcard_hyphen() to allow dash vs underscore equivalence in query-modname vs KBUILD_MODFILE string, noted by sashiko. v3: new patch in rev-3 use KBUILD_MODFILE to provide modname for builtin modules, giving unnique values that KBUILD_MODANME does not provide. --- Documentation/admin-guide/dynamic-debug-howto.rst | 40 +++++----- include/linux/dynamic_debug.h | 17 +++- lib/dynamic_debug.c | 3 +- .../selftests/dynamic_debug/dyndbg_selftest.sh | 93 +++++++++++++++++++++- 4 files changed, 126 insertions(+), 27 deletions(-) diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst b/Documentation/admin-guide/dynamic-debug-howto.rst index 9c2f096ed1d8..8befb69575b7 100644 --- a/Documentation/admin-guide/dynamic-debug-howto.rst +++ b/Documentation/admin-guide/dynamic-debug-howto.rst @@ -38,12 +38,12 @@ You can view the currently configured behaviour in the *prdbg* catalog:: :#> head -n7 /proc/dynamic_debug/control # filename:lineno [module]function flags format - init/main.c:1179 [main]initcall_blacklist =_ "blacklisting initcall %s\n" - init/main.c:1218 [main]initcall_blacklisted =_ "initcall %s blacklisted\n" - init/main.c:1424 [main]run_init_process =_ " with arguments:\n" - init/main.c:1426 [main]run_init_process =_ " %s\n" - init/main.c:1427 [main]run_init_process =_ " with environment:\n" - init/main.c:1429 [main]run_init_process =_ " %s\n" + init/main.c:1179 [init/main]initcall_blacklist =_ "blacklisting initcall %s\n" + init/main.c:1218 [init/main]initcall_blacklisted =_ "initcall %s blacklisted\n" + init/main.c:1424 [init/main]run_init_process =_ " with arguments:\n" + init/main.c:1426 [init/main]run_init_process =_ " %s\n" + init/main.c:1427 [init/main]run_init_process =_ " with environment:\n" + init/main.c:1429 [init/main]run_init_process =_ " %s\n" The 3rd space-delimited column shows the current flags, preceded by a ``=`` for easy use with grep/cut. ``=p`` shows enabled callsites. @@ -59,10 +59,10 @@ query/commands to the control file. Example:: :#> ddcmd '-p; module main func run* +p' :#> grep =p /proc/dynamic_debug/control - init/main.c:1424 [main]run_init_process =p " with arguments:\n" - init/main.c:1426 [main]run_init_process =p " %s\n" - init/main.c:1427 [main]run_init_process =p " with environment:\n" - init/main.c:1429 [main]run_init_process =p " %s\n" + init/main.c:1424 [init/main]run_init_process =p " with arguments:\n" + init/main.c:1426 [init/main]run_init_process =p " %s\n" + init/main.c:1427 [init/main]run_init_process =p " with environment:\n" + init/main.c:1429 [init/main]run_init_process =p " %s\n" Error messages go to console/syslog:: @@ -161,17 +161,19 @@ file file kernel/freezer.c # ie column 1 of control file file drivers/usb/* # all callsites under it file inode.c:start_* # parse :tail as a func (above) - file inode.c:1-100 # parse :tail as a line-range (above) + file inode.c:1-100 # parse :tail as a line-range (below) module - The given string is compared against the module name - of each callsite. The module name is the string as - seen in ``lsmod``, i.e. without the directory or the ``.ko`` - suffix and with ``-`` changed to ``_``. Examples:: - - module sunrpc - module nfsd - module drm* # both drm, drm_kms_helper + The query string is compared against the subsystem module name of + each callsite, as shown in the control file. The simple module + name is the string as seen in ``lsmod``, i.e. without the + directory or the ``.ko`` suffix and with ``-`` changed to ``_``. + + Examples:: + + module nfsd # simple modname (as from lsmod) + module init/main # subsystem modname (as in control file) + module drm* # both drm, drm_kms_helper format The given string is searched for in the dynamic debug format diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h index 2d6983186f37..aee6f3d0916f 100644 --- a/include/linux/dynamic_debug.h +++ b/include/linux/dynamic_debug.h @@ -8,6 +8,17 @@ #include <linux/build_bug.h> +/* + * Pick the best name for the module: + * KBUILD_MODFILE includes the path (e.g., drivers/usb/core/usbcore) for built-ins. + * Fall back to KBUILD_MODNAME for modules (loader requires unique names). + */ +#ifdef KBUILD_MODFILE +# define DDEBUG_MODNAME KBUILD_MODFILE +#else +# define DDEBUG_MODNAME KBUILD_MODNAME +#endif + /* * An instance of this structure is created in a special * ELF section at every dynamic debug callsite. At runtime, @@ -128,9 +139,9 @@ struct _ddebug_class_param { #define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \ static const char *_var##_classnames[] = { __VA_ARGS__ }; \ static struct _ddebug_class_map __aligned(8) __used \ - __section("__dyndbg_class_maps") _var = { \ + __section("__dyndbg_class_maps") _var = { \ .mod = THIS_MODULE, \ - .mod_name = KBUILD_MODNAME, \ + .mod_name = DDEBUG_MODNAME, \ .base = _base, \ .map_type = _maptype, \ .length = ARRAY_SIZE(_var##_classnames), \ @@ -169,7 +180,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor, #define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \ static struct _ddebug __aligned(8) \ __section("__dyndbg_descs") name = { \ - .modname = KBUILD_MODNAME, \ + .modname = DDEBUG_MODNAME, \ .function = __func__, \ .filename = __FILE__, \ .format = (fmt), \ diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c index 996daf0a05b5..b6c5634096fa 100644 --- a/lib/dynamic_debug.c +++ b/lib/dynamic_debug.c @@ -248,7 +248,8 @@ static int ddebug_change(const struct ddebug_query *query, /* match against the module name */ if (query->module && - !match_wildcard(query->module, di->mod_name)) + !match_wildcard_hyphen(query->module, di->mod_name) && + !match_wildcard_hyphen(query->module, kbasename(di->mod_name))) continue; if (query->class_string) { diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh index 1239f1e10591..26cca9f24799 100755 --- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh +++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh @@ -76,9 +76,9 @@ function handle_exit_code() { # $1 - pattern to match, pattern in $1 is enclosed by spaces for a match ""\s$1\s" # $2 - number of times the pattern passed in $1 is expected to match # $3 - optional can be set either to "-r" or "-v" -# "-r" means relaxed matching in this case pattern provided in $1 is passed -# as is without enclosing it with spaces -# "-v" prints matching lines +# "-r" means relaxed matching in this case pattern provided in +# $1 is passed as is without enclosing it with spaces "-v" +# prints matching lines # $4 - optional when $3 is set to "-r" then $4 can be used to pass "-v" function check_match_ct { pattern="\s$1\s" @@ -223,7 +223,7 @@ function basic_tests { check_match_ct =p 0 # module params are builtin to handle boot args - check_match_ct '\[params\]' 4 -r + check_match_ct '\[kernel/params\]' 4 -r ddcmd module params +mpf check_match_ct =pmf 4 @@ -238,8 +238,93 @@ EOF ddcmd =_ } +function test_subsystem_module_queries { + echo -e "${GREEN}# TEST_SUBSYTEM_MODULE_QUERIES ${NC}" + ddcmd =_ + + # Find how many 'main' modules we have in total (by basename) + # Use a more precise regex to avoid false positives like [irqdomain] + local total_main=$(grep -c "\[\([^]]*/\)\?main\]" /proc/dynamic_debug/control) + echo "# found $total_main total 'main' modules" + + if [ $total_main -eq 0 ]; then + echo "SKIP - no 'main' modules found to test slashes" + return + fi + + echo "# testing 'module */main'" + ddcmd module "*/main" +p + # This should match modules that HAVE a slash and end in /main + local slash_main=$(grep -c "\[[^]]*/main\]" /proc/dynamic_debug/control) + check_match_ct =p $slash_main -r + + echo "# testing 'module init/main' (specific path)" + ddcmd =_ + ddcmd module "init/main" +p + local init_main=$(grep -c "\[init/main\]" /proc/dynamic_debug/control) + check_match_ct =p $init_main + + echo "# testing 'module main' (basename match)" + ddcmd =_ + ddcmd module main +p + # This should match ALL $total_main entries due to kbasename matching + check_match_ct =p $total_main + + ddcmd =_ +} + +function test_hyphen_underscore { + echo -e "${GREEN}# TEST_HYPHEN_UNDERSCORE ${NC}" + ddcmd =_ + + # Find a module with a hyphen in its name (e.g., from the control file) + local mod_with_hyphen=$(grep -m1 "\[[^]]*-[^]]*\]" /proc/dynamic_debug/control | sed -n 's/.*\[\(.*\)\].*/\1/p') + + if [ -z "$mod_with_hyphen" ]; then + echo "SKIP - no module with hyphen found in /proc/dynamic_debug/control" + return + fi + + echo "# testing hyphen/underscore equivalence for module: $mod_with_hyphen" + local mod_with_underscore=$(echo "$mod_with_hyphen" | tr '-' '_') + + # 1. Enable using literal hyphen name + echo "# trying hyphen name: $mod_with_hyphen" + ddcmd module "$mod_with_hyphen" +p + local count_hyphen=$(grep -c "\[$mod_with_hyphen\]" /proc/dynamic_debug/control) + check_match_ct =p $count_hyphen -r + + # 2. Disable and then enable using underscore name + ddcmd =_ + echo "# trying underscore name: $mod_with_underscore" + ddcmd module "$mod_with_underscore" +p + check_match_ct =p $count_hyphen -r + + # 3. Try kbasename with hyphen (if it has a path) + local base_hyphen=$(basename "$mod_with_hyphen") + if [ "$base_hyphen" != "$mod_with_hyphen" ]; then + ddcmd =_ + echo "# trying hyphen kbasename: $base_hyphen" + ddcmd module "$base_hyphen" +p + local count_base=$(grep -c "\[\([^]]*/\)\?$base_hyphen\]" /proc/dynamic_debug/control) + check_match_ct =p $count_base -r + fi + + # 4. Try kbasename with underscore + local base_underscore=$(echo "$base_hyphen" | tr '-' '_') + ddcmd =_ + echo "# trying underscore kbasename: $base_underscore" + ddcmd module "$base_underscore" +p + local count_base=$(grep -c "\[\([^]]*/\)\?$base_hyphen\]" /proc/dynamic_debug/control) + check_match_ct =p $count_base -r + + ddcmd =_ +} + tests_list=( basic_tests + test_subsystem_module_queries + test_hyphen_underscore ) # Run tests -- 2.54.0
