From: Jim Cromie <[email protected]>
Currently, dyndbg binds KBUILD_MODNAME into callsite & classmap
declarator-macros. While loadable modules have unique names enforced at
modprobe, for built-ins, its values suffer some collisions (e.g.
multiple distinct compilation units named "main", "core", or "init").
KBUILD_MODNAME defaults to the leaf of the pathname, so built-in
subsystems are fragmented into the names of their individual
implementation parts. The callsites remain adjacent in their subsystem
directories, but expose 278 separate module labels in
/proc/dynamic_debug/control instead of unified subsystem addresses.
Bind DDEBUG_MODNAME into all callsite and classmap declarator macros
instead. In include/linux/dynamic_debug.h, define DDEBUG_MODNAME to
cascade across KBUILD_DD_MODNAME, KBUILD_MODFILE, and KBUILD_MODNAME.
In scripts/Makefile.lib, compute KBUILD_DD_MODNAME with structured
precedence:
0. Check for per-target override: DD_MODNAME_<target-stem>.o
1. Check for directory-level override: DD_MODNAME in local Makefile
2. Fall back to automatic clean heuristic:
- Strip leading "drivers/" and arch prefixes.
- Map top-level built-in targets to directory names (e.g. power,
init).
- Unify multi-target shared helpers under containing subsystem paths
(e.g. mmc/host, coco/sev, events/amd, kernel/cpu).
- Sanitize commas, hyphens, and whitespace to prevent token
splitting in column 2 of /proc/dynamic_debug/control.
In /proc/dynamic_debug/control on a default boot, unique built-in module
names drop from 278 to 211, consolidating 67 fragmented targets:
Subsystem Group Legacy Names (linux.git) Consolidated Name (wk-A)
---------------- ---------------------------- ------------------------
Power snapshot, swap, suspend, power
hibernate, main, em
Kernel Init main, init, init_64, init
initramfs, do_mounts
Sound / HDA snd_hda_codec_*, snd_intel* sound/hda/codecs,
snd_hda_core, snd_hda_intel sound/hda/controllers
TTY & Serial 8250, 8250_base, 8250_pci, tty/serial,
8250_exar, serial_base tty/serial/8250
GPU / DRM drm, drm_kms_helper, gpu/drm, gpu/drm/display
bridge, display, clients gpu/drm/clients, tiny
ACPI & Platform acpi, acpi_dma, acpi_x86, acpi, acpi/numa,
numa, srat acpi/x86
IOMMU & Perf amd_node, dmar, iommu, iommu/amd, iommu/intel,
ibs, events events/amd, events/intel
Input atkbd, psmouse, libps2 input/keyboard, mouse
Filesystems fuse, overlay, inotify_user fs/fuse, fs/overlayfs,
sysfs, kernfs fs/notify/inotify
Networking tcp, tcp_input, tcp_cong, net/core, net/ipv4,
tcp_cubic, arp, icmp net/sched
This yields unambiguous, user-visible subsystem namespaces across both
built-in objects and loadable modules while maintaining compatibility
with wildcard queries (e.g. `module main` matching `[*/main]`).
Adjust documentation and selftests to track refreshed module names.
Signed-off-by: Jim Cromie <[email protected]>
Revision history (v9):
. implement subsystem-centric KBUILD_DD_MODNAME naming heuristic.
. unify multi-target shared helpers under containing subsystem path.
. eliminate whitespace splitting in control file column 2.
---
Documentation/admin-guide/dynamic-debug-howto.rst | 42 ++++---
include/linux/dynamic_debug.h | 19 ++-
kernel/power/Makefile | 2 +
lib/dynamic_debug.c | 3 +-
scripts/Makefile.lib | 26 ++++
.../selftests/dynamic_debug/dyndbg_selftest.sh | 137 +++++++++++----------
6 files changed, 143 insertions(+), 86 deletions(-)
diff --git a/Documentation/admin-guide/dynamic-debug-howto.rst
b/Documentation/admin-guide/dynamic-debug-howto.rst
index 9c2f096ed1d8..99bbae37d34e 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 +161,21 @@ 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, or its simple name.
+ 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 */main # any subsystem ending in main
+ module main # simple modname, selects same as above
+ 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 baf5c0853f45..54a80e7fdbaf 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -10,6 +10,21 @@
#define __DDEBUG_ARRAY_SIZE(arr) (sizeof(arr) / sizeof((arr)[0]))
+/*
+ * DDEBUG_MODNAME resolves from:
+ * 1. KBUILD_DD_MODNAME: Subsystem-scoped, sanitized name from
scripts/Makefile.lib
+ * (supports directory-level DD_MODNAME and per-target
DD_MODNAME_<target>.o).
+ * 2. KBUILD_MODFILE: Path-based fallback for specialized or out-of-tree
builds.
+ * 3. KBUILD_MODNAME: Default kernel module target name.
+ */
+#ifdef KBUILD_DD_MODNAME
+# define DDEBUG_MODNAME KBUILD_DD_MODNAME
+#elif defined(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,
@@ -121,7 +136,7 @@ struct ddebug_class_param {
static struct ddebug_class_map __aligned(8) __used \
__section("__dyndbg_classes") _var = { \
.mod = THIS_MODULE, \
- .mod_name = KBUILD_MODNAME, \
+ .mod_name = DDEBUG_MODNAME, \
.base = _base, \
.map_type = _maptype, \
.class_names = _var##_classnames, \
@@ -160,7 +175,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \
static struct _ddebug __aligned(8) \
__section("__dyndbg") name = { \
- .modname = KBUILD_MODNAME, \
+ .modname = DDEBUG_MODNAME, \
.function = __func__, \
.filename = __FILE__, \
.format = (fmt), \
diff --git a/kernel/power/Makefile b/kernel/power/Makefile
index 773e2789412b..ddceacfd76d7 100644
--- a/kernel/power/Makefile
+++ b/kernel/power/Makefile
@@ -1,5 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
+DD_MODNAME := power
+
ifeq ($(CONFIG_DYNAMIC_DEBUG), y)
CFLAGS_swap.o := -DDEBUG
CFLAGS_snapshot.o := -DDEBUG
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 2a69f86f973e..d4dbbd1a91ef 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -242,7 +242,8 @@ static int ddebug_change(const struct ddebug_query *query,
/* match against the module name */
if (query->module &&
- !match_wildcard(query->module, dt->mod_name))
+ !match_wildcard_hyphen(query->module, dt->mod_name) &&
+ !match_wildcard_hyphen(query->module,
kbasename(dt->mod_name)))
continue;
if (query->class_string) {
diff --git a/scripts/Makefile.lib b/scripts/Makefile.lib
index 0a4fdd8bd975..e129c4d10ed8 100644
--- a/scripts/Makefile.lib
+++ b/scripts/Makefile.lib
@@ -23,6 +23,32 @@ modname_flags = -DKBUILD_MODNAME=$(call
name-fix,$(modname)) \
-D__KBUILD_MODNAME=$(call name-fix-token,$(modname))
modfile_flags = -DKBUILD_MODFILE=$(call stringify,$(modfile))
+# Dynamic debug subsystem modname with clean heuristic and override support
+dd_modname_override = $(strip $(firstword $(DD_MODNAME_$(target-stem).o) \
+ $(DD_MODNAME)))
+dd_obj := $(strip $(filter-out .,\
+ $(patsubst drivers/%,%,\
+ $(patsubst arch/$(SRCARCH)/%,%,\
+ $(patsubst arch/%/,%,$(obj))))))
+dd_modname_default = $(strip $(if $(filter $(notdir $(obj)),$(__modname)),\
+ $(__modname),\
+ $(if $(filter main core common util init snapshot \
+ process,$(__modname)),\
+ $(dd_obj),\
+ $(if $(word 2,$(__modname)),\
+ $(dd_obj),\
+ $(if $(dd_obj),$(dd_obj),$(__modname))))))
+dd_modname = $(strip $(or $(dd_modname_override),\
+ $(dd_modname_default),\
+ $(__modname)))
+dd-name-subst = $(subst $(comma),_,$(subst -,_,$(strip $1)))
+dd-name-fix-token = $(subst $(space),_,$(call dd-name-subst,$1))
+dd_tok = $(call dd-name-fix-token,$(dd_modname))
+dd_modname_flags = $(if $(dd_modname),\
+ -DKBUILD_DD_MODNAME=$(call stringify,$(dd_tok)))
+
+modfile_flags += $(dd_modname_flags)
+
_c_flags = $(filter-out $(CFLAGS_REMOVE_$(target-stem).o), \
$(filter-out $(ccflags-remove-y), \
$(KBUILD_CPPFLAGS) $(KBUILD_CFLAGS) $(ccflags-y)) \
diff --git a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
index 69a1787a4302..5ef6e313fa4b 100755
--- a/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
+++ b/tools/testing/selftests/dynamic_debug/dyndbg_selftest.sh
@@ -308,98 +308,114 @@ function FT_grammar_errs {
ddcmd =_
}
-# these queries run against the builtin module: params, and change
-# flags. The control file state-of-interest is found by path,
-# kernel/params.c, to avoid module keyword entirely
+# these queries run against the builtin file: kernel/params.c, and change
+# flags. The control file state-of-interest is found by path $f,
+# perfectly binding the stimulus scope to the observation slice.
function FT_basic_queries {
v_echo "${GREEN}# BASIC_TESTS ${NC}"
if [ $LACK_DD_BUILTIN -eq 1 ]; then
- echo "SKIP - test requires params, which is a builtin module"
+ echo "SKIP - test requires dynamic_debug built into kernel"
return
fi
+ local f='kernel/params.c'
ddcmd =_ # zero everything
- ddcmd "module params +mf" 'kernel/params.c'
- ddcmd "module params +l" 'kernel/params.c'
- ddcmd "module params -m" 'kernel/params.c'
- ddcmd "module params =_" 'kernel/params.c'
+ ddcmd "file $f +mf" "$f"
+ ddcmd "file $f +l" "$f"
+ ddcmd "file $f -m" "$f"
+ ddcmd "file $f =_" "$f"
# multi-query commands split on ; on a single line
- ddcmd "module params +mf ; module params func parse_args +sl"
'kernel/params.c'
+ ddcmd "file $f +mf ; file $f func parse_args +sl" "$f"
# verify multi-cmd input, newline separated, with embedded comments
ddcmd =_ # reset before multiline query to capture full transition
- ddcmd "module params =_ # clear params
- module params +ml # set flags
- module params func parse_args +fs # set other flags" \
- 'kernel/params.c'
+ ddcmd "file $f =_ # clear params
+ file $f +ml # set flags
+ file $f func parse_args +fs # set other flags" \
+ "$f"
# clear flags and verify
- ddcmd "module params =_" 'kernel/params.c'
+ ddcmd "file $f =_" "$f"
}
function FT_path_module_queries {
v_echo "${GREEN}# TEST_PATH_MODULE_QUERIES ${NC}"
ddcmd =_
- # Find how many 'main' modules we have in total (by basename)
- # Use a precise OR pattern to match exactly [main] or [*/main] and avoid
irqdomain
- local total_main=$(grep -c "\[main\]\|\[[^]]*/main\]"
/proc/dynamic_debug/control)
- v_echo "# found $total_main total 'main' modules"
+ # Find a module with a path/slash in its name from the control file
+ local slashed_mod
+ slashed_mod=$(awk -F'[][]' \
+ '/^[^#:]+:[0-9]+/ { if ($2 ~ /\//) { print $2; exit } }' \
+ /proc/dynamic_debug/control)
- if [ $total_main -eq 0 ]; then
- echo "SKIP - no 'main' modules found to test slashes"
+ if [ -z "$slashed_mod" ]; then
+ echo "SKIP - no slashed module found to test paths"
return
fi
- # Verify a robust, cross-query state-interaction handshake between
- # narrow path and wide wildcard/basename queries. This dynamically
- # proves they interact with the exact same underlying callsites!
+ local base_mod=$(basename "$slashed_mod")
+ local slice_pattern="\[$slashed_mod\]"
+
+ v_echo "# testing path module queries for module: $slashed_mod (basename:
$base_mod)"
+
+ # 1. Turn ON specific path
+ ddcmd "module '$slashed_mod' +p"
+ local hash_path=$(slice_and_hash_ddctrl "$slice_pattern")
- # 1. Turn ON specific path, verified under '[init/main]' range
- ddcmd "module 'init/main' +p" "init/main.c"
+ # 2. Turn OFF using wide wildcard query
+ ddcmd "module '*/$base_mod' =_"
+ local hash_off=$(slice_and_hash_ddctrl "$slice_pattern")
- # 2. Turn OFF using wide wildcard query,
- ddcmd "module '*/main' =_" "init/main.c"
+ # 3. Turn ON using wide unscoped basename
+ ddcmd "module '$base_mod' +p"
+ local hash_base=$(slice_and_hash_ddctrl "$slice_pattern")
- # 3. Turn ON using wide unscoped basename,
- ddcmd "module 'main' +p" "init/main.c"
+ # 4. Turn OFF using specific narrow path
+ ddcmd "module '$slashed_mod' =_"
- # 4. Turn OFF using specific narrow path,
- ddcmd "module 'init/main' =_" "init/main.c"
+ if [ "$hash_path" != "$hash_base" ]; then
+ echo -e "${RED}: Path vs Basename equivalence check failed! " \
+ "Fingerprints do not match.${NC}"
+ exit $ksft_fail
+ else
+ v_echo "${GREEN}: Proven: Slashed path and basename module queries
match!${NC}"
+ fi
+
+ ddcmd =_
}
function FT_hyphen_underscore {
v_echo "${GREEN}# TEST_HYPHEN_UNDERSCORE ${NC}"
ddcmd =_
- # Find a module with a hyphen in its name (e.g., from the control file)
- local mod_with_hyphen
- mod_with_hyphen=$(awk -F'[][]' \
- '/^[^#:]+:[0-9]+/ { if ($2 ~ /-/) { print $2; exit } }' \
+ # Find a module with an underscore in its name (e.g., from the control
file)
+ local mod_with_underscore
+ mod_with_underscore=$(awk -F'[][]' \
+ '/^[^#:]+:[0-9]+/ { if ($2 ~ /_/) { print $2; exit } }' \
/proc/dynamic_debug/control)
- if [ -z "$mod_with_hyphen" ]; then
- echo "SKIP - no module with hyphen found in
/proc/dynamic_debug/control"
+ if [ -z "$mod_with_underscore" ]; then
+ echo "SKIP - no module with underscore found in
/proc/dynamic_debug/control"
return
fi
- v_echo "# testing hyphen/underscore equivalence for module:
$mod_with_hyphen"
- local mod_with_underscore=$(echo "$mod_with_hyphen" | tr '-' '_')
+ local mod_with_hyphen=$(echo "$mod_with_underscore" | tr '_' '-')
+ local base_underscore=$(basename "$mod_with_underscore")
local base_hyphen=$(basename "$mod_with_hyphen")
- local slice_pattern="\[[^]]*$base_hyphen\]"
+ local slice_pattern="\[$mod_with_underscore\]"
+
+ v_echo "# testing hyphen/underscore equivalence for module:
$mod_with_underscore (hyphen: $mod_with_hyphen)"
# 1. Enable using literal hyphen name, and record the state fingerprint
v_echo "# trying hyphen name: $mod_with_hyphen"
- ddcmd "module $mod_with_hyphen +p"
- # verify_control_slice "$slice_pattern"
+ ddcmd "module '$mod_with_hyphen' +p"
local hash_hyphen=$(slice_and_hash_ddctrl "$slice_pattern")
# 2. Disable and enable using underscore name, record the state fingerprint
ddcmd =_
v_echo "# trying underscore name: $mod_with_underscore"
- ddcmd "module $mod_with_underscore +p"
- # verify_control_slice "$slice_pattern"
+ ddcmd "module '$mod_with_underscore' +p"
local hash_underscore=$(slice_and_hash_ddctrl "$slice_pattern")
# Real-time mathematical proof of hyphen/underscore name equivalence!
@@ -413,19 +429,17 @@ function FT_hyphen_underscore {
v_echo "${GREEN}: Proven: Hyphen/Underscore literal name equivalence
matches!${NC}"
fi
- # Try kbasename with hyphen (if it has a path)
+ # 3. Try kbasename with hyphen (if it has a path)
if [ "$base_hyphen" != "$mod_with_hyphen" ]; then
ddcmd =_
v_echo "# trying hyphen kbasename: $base_hyphen"
- ddcmd "module $base_hyphen +pmf"
- # verify_control_slice "$slice_pattern" # omitted: slice contains
dynamic
- # module info which drifts across different targets
+ ddcmd "module '$base_hyphen' +pmf"
local hash_base_hyphen=$(slice_and_hash_ddctrl "$slice_pattern")
# Prove kbasename hyphen name matches literal path hyphen name (with
different flags)!
v_echo "# trying full path hyphen with pmf flags"
ddcmd =_
- ddcmd "module $mod_with_hyphen +pmf"
+ ddcmd "module '$mod_with_hyphen' +pmf"
local hash_path_pmf=$(slice_and_hash_ddctrl "$slice_pattern")
if [ "$hash_path_pmf" != "$hash_base_hyphen" ]; then
echo -e "${RED}: Hyphen kbasename check failed! " \
@@ -438,17 +452,13 @@ function FT_hyphen_underscore {
fi
# 4. Try kbasename with underscore
- local base_underscore=$(echo "$base_hyphen" | tr '-' '_')
ddcmd =_
v_echo "# trying underscore kbasename: $base_underscore"
- ddcmd "module $base_underscore +pmf"
- # verify_control_slice "$slice_pattern" # omitted: slice contains dynamic
- # module info which drifts across different targets
+ ddcmd "module '$base_underscore' +pmf"
local hash_base_underscore=$(slice_and_hash_ddctrl "$slice_pattern")
# Real-time mathematical proof of hyphen/underscore kbasename equivalence!
- if [ "$hash_base_hyphen" != "$hash_base_underscore" ] && \
- [ -n "$hash_base_hyphen" ]; then
+ if [ -n "$hash_base_hyphen" ] && [ "$hash_base_hyphen" !=
"$hash_base_underscore" ]; then
echo -e "${RED}: Hyphen/Underscore kbasename equivalence check " \
"failed! Fingerprints do not match.${NC}"
exit $ksft_fail
@@ -460,7 +470,6 @@ function FT_hyphen_underscore {
ddcmd =_
}
-
# testing classmap-based query enablers and class configurations
function FT_test_classes {
v_echo "${GREEN}# TEST_CLASSES - classmap-based query enablers and class
configs ${NC}"
@@ -590,7 +599,7 @@ builtin_tests=(
FT_grammar_ok
FT_grammar_errs
FT_basic_queries
- #FT_path_module_queries
+ FT_path_module_queries
FT_hyphen_underscore
)
@@ -657,13 +666,13 @@ function GOLDEN_RECORDS {
#K= 781995971d28f732a792522f3c56cdd3 FT_grammar_errs.40
#K= 6614a677d9f9ac09d9825b4e989d2c42 FT_grammar_errs.41
#K= 70de9afed457a6be9f9c3c81cbd6d4d5 FT_grammar_errs.42
-#K= 6e8599556a312200fb6d484565b6c52f FT_basic_queries.1
-#K= db17180b59444e5e34a8fc20c40e4530 FT_basic_queries.2
-#K= f7bd56bd407ff255ef2e3b5fb093ae6a FT_basic_queries.3
-#K= 4ce44468b3b5f80ae42ade1f261b952f FT_basic_queries.4
-#K= 02e4fd94602e108cb89bfc70d47a5dad FT_basic_queries.5
-#K= f03a7ca7316e8db4c0e16523dc41e75d FT_basic_queries.6
-#K= c518a50ba30ba8099d0dc874a27ecf16 FT_basic_queries.7
+#K= 3c445fb23d701041e920a2a6d2b022c7 FT_basic_queries.1
+#K= d8eb8f226860aa558fb8a98097f05be9 FT_basic_queries.2
+#K= 6a86bb9209a3a0492bc6c2d29f4d5e52 FT_basic_queries.3
+#K= 90804574a5336971465f92d6cc3aa7fb FT_basic_queries.4
+#K= f2b4f24fece9c55f5a5d28323c2019f8 FT_basic_queries.5
+#K= 8c2dd1164fbcefb721345ce62a864a37 FT_basic_queries.6
+#K= 4542e1e5e7eadcbe8f90a9c934635618 FT_basic_queries.7
EOF
# Read the K-recs and skip those for tests that can't run
while read -r line; do
--
2.55.0
