DECLARE_DYNDBG_CLASSMAP() has a design error; its usage fails a basic
K&R rule: "define once, refer many times".
When DRM_USE_DYNAMIC_DEBUG=y, it is used across DRM core & drivers;
each invocation allocates/inits the classmap understood by that
module. All must match for the modules to respond together when
DRM.debug categories are enabled. This is brittle; a maintenance
foot-gun.
Further, its culpable in the CONFIG_DRM_USE_DYNAMIC_DEBUG=Y
regression; its use in both core & drivers obfuscates the 2 roles, that
caused incomplete initialization when modprobing drivers:
1st drm.ko loads, and dyndbg initializes its DRM.debug callsites, then
a drm-driver loads, but too late for the DRM.debug enablement.
So retire it, replace with 2 macros:
DYNAMIC_DEBUG_CLASSMAP_DEFINE - invoked once from core - drm.ko
DYNAMIC_DEBUG_CLASSMAP_USE - from all drm drivers and helpers.
DYNAMIC_DEBUG_CLASSMAP_DEFINE: this reworks DECLARE_DYNDBG_CLASSMAP,
by dropping the static qualifier on the classmap, and exporting it
instead.
DYNAMIC_DEBUG_CLASSMAP_USE: then refers to the exported var by name:
used from drivers, helper-mods
lets us drop the repetitive "classname" declarations
fixes 2nd-defn problem
creates a ddebug_class_user record in new __dyndbg_class_users section
new section is scanned "differently"
DECLARE_DYNDBG_CLASSMAP is preserved temporarily, to decouple DRM
adaptation work and avoid compile-errs before its done. IOW, DRM gets
these fixes when they commit the adopt-new-api patches.
The DEFINE,USE distinction, and the separate classmap-use record,
allows dyndbg to initialize the driver's & helper's DRM.debug
callsites separately after each is modprobed.
Basically, the classmap init-scan is repeated for classmap-users.
To review, dyndbg's existing __dyndbg_classes[] section does:
. catalogs the module's classmaps
. tells dyndbg about them, allowing >control
. DYNAMIC_DEBUG_CLASSMAP_DEFINE creates section records.
. we rename it to: __dyndbg_class_maps[]
Then this patch adds __dyndbg_class_users[] section:
. catalogs users of classmap definitions elsewhere
. authorizes dyndbg to >control user's class'd prdbgs
. DYNAMIC_DEBUG_CLASSMAP_USE() creates section records.
Now ddebug_add_module(etal) can handle classmap-uses similar to (and
after) classmaps; when a dependent module is loaded, if it has
classmap-uses (to a classmap-def in another module), that module's
kernel params are scanned to find if it has a kparam that is wired to
dyndbg's param-ops, and whose classmap is the one being ref'd.
To support this, theres a few data/header changes:
new struct ddebug_class_user
contains: user-module-name, &classmap-defn
it records drm-driver's use of a classmap in the section, allowing lookup
struct ddebug_info gets 2 new fields for the new sections:
class_users, num_class_users.
set by dynamic_debug_init() for builtins.
or by kernel/module/main:load_info() for loadable modules.
vmlinux.lds.h: new BOUNDED_SECTION for __dyndbg_class_users
dynamic_debug.c has 2 changes in ddebug_add_module(), ddebug_change():
ddebug_add_module()
called ddebug_attach_module_classes()
now calls ddebug_apply_class_maps() & ddebug_apply_class_users()
these both call ddebug_apply_params().
ddebug_apply_params(new fn):
It scans module's/builtin kernel-params, calls ddebug_match_apply_kparam
for each to find any params/sysfs-nodes which may be wired to a classmap.
ddebug_match_apply_kparam(new fn):
1st, it tests the kernel-param.ops is dyndbg's; this guarantees that
the attached arg is a struct ddebug_class_param, which has a ref to
the param's state, and to the classmap defining the param's handling.
2nd, it requires that the classmap ref'd by the kparam is the one
we're called for; modules can use many separate classmaps (as
test_dynamic_debug does).
Then apply the "parent" kparam's setting to the dependent module,
using ddebug_apply_class_bitmap().
ddebug_change(and callees) also gets adjustments:
ddebug_find_valid_class(): This does a search over the module's
classmaps, looking for the class FOO echo'd to >control. So now it
searches over __dyndbg_class_users[] after __dyndbg_classes[].
ddebug_class_name(): return class-names for defined AND used classes.
test_dynamic_debug.c, test_dynamic_debug_submod.c:
This demonstrates the 2 types of classmaps & sysfs-params, following
the 4-part recipe:
1. define an enum for the classmap: DRM.debug has DRM_UT_{CORE,KMS,...}
multiple classes must share 0-62 classid space.
2. DYNAMIC_DEBUG_CLASSMAP_DEFINE(.. DRM_UT_{CORE,KMS,...})
3. DYNAMIC_DEBUG_CLASSMAP_PARAM* (classmap)
4. DYNAMIC_DEBUG_CLASSMAP_USE()
by _submod only, skipping 2,3
Move all the enum declarations together, to better explain how they
share the 0..62 class-id space available to a module (non-overlapping
subranges).
reorg macros 2,3 by name. This gives a tabular format, making it easy
to see the pattern of repetition, and the points of change.
And extend the test to replicate the 2-module (parent & dependent)
scenario which caused the CONFIG_DRM_USE_DYNAMIC_DEBUG=y regression
seen in drm & drivers.
The _submod.c is a 2-line file: #define _SUBMOD, #include parent.
This gives identical complements of prdbgs in parent & _submod, and
thus identical print behavior when all of: >control, >params, and
parent->_submod propagation are working correctly.
It also puts all the parent/_submod declarations together in the same
source, with the new ifdef _SUBMOD block invoking DYNAMIC_DEBUG_CLASSMAP_USE
for the 2 test-interfaces. I think this is clearer.
These 2 modules are both tristate, allowing 3 super/sub combos: Y/Y,
Y/M, M/M (not N/Y, since this is disallowed by dependence).
Y/Y testing exposed a missing __align(8) in the _METADATA macro, which
M/M didn't see because the module-loader memory placement constrains
it instead.
Fixes: aad0214f3026 ("dyndbg: add DECLARE_DYNDBG_CLASSMAP macro")
cc: linux-doc@xxxxxxxxxxxxxxx
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
v2 a. building 2 .ko's from 1 source file is weird; add a clear
comment at the top to justify it (basically cloning)
ln 138+ in commit-msg is insufficient.
b. retire "DYNDBG_" name shortening b4 adding _CLASSMAP_* macros.
c. s/dd_class/_ddebug_class/
d. s/\bddebug\b/_$1/g in header: chgs 1 struct and UNIQUE_ID bases
v1.9 - commit-msg tweaks
DRM:CHECK warnings on macros: add parens
extern DEFINEd _var, static classnames
change ddebug_class_user.user_mod_name to .mod_name
simplify ddebug_find_valid_class
improve vpr_cm_info msg format
wrap (base) in macro body
move __DYNDBG_CLASSMAP_CHECK above kdoc for DYNDBG_CLASSMAP_DEFINE
v1.8 - split drm parts to separate commits.
preserve DECLARE_DYNDBG_CLASSMAP to decouple DRM, no flag day.
fixup block comment
v1.7 - previous submission-blocking bug:
missing __align(8) in DYNAMIC_DEBUG_DECLARE_METADATA on
ddebug_class_user caused corrupt records, but only for builtin
modules; module loader code probably pinned allocations to the right
alignment naturally, hiding the bug for typical builds.
v6- get rid of WARN_ON_ONCE
v?- fix _var expanded 2x in macro
dyndbg:
This fn formerly returned the map which contained the class (thus
validating it), and as a side-effect set the class-id in an outvar.
But the caller didn't use the map (after checking its not null), only
the valid class-id. So simplify the fn to return the class-id of the
validated classname, or -ENOENT when the queried classname is not
found.
Convey more useful info in the debug-msg: print class-names[0,last],
and [base,+len] instead of the class-type printout, which is almost
always "type:DISJOINT_BITS". And drop ddebug_classmap_typenames,
which is now unused.
[root@v6 b0-dd]# modprobe test_dynamic_debug_submod
[ 18.864962] dyndbg: loaded classmap: test_dynamic_debug [16..24] V0..V7
[ 18.865046] dyndbg: found kp:p_level_num =0x0
[ 18.865048] dyndbg: mapped to: test_dynamic_debug [16..24] V0..V7
[ 18.865164] dyndbg: p_level_num: lvl:0 bits:0x0
[ 18.865217] dyndbg: loaded classmap: test_dynamic_debug [0..10] D2_CORE..D2_DRMRES
[ 18.865297] dyndbg: found kp:p_disjoint_bits =0x0
[ 18.865298] dyndbg: mapped to: test_dynamic_debug [0..10] D2_CORE..D2_DRMRES
[ 18.865424] dyndbg: p_disjoint_bits: classbits: 0x0
[ 18.865472] dyndbg: module:test_dynamic_debug attached 2 classmaps
[ 18.865533] dyndbg: 23 debug prints in module test_dynamic_debug
[ 18.866558] dyndbg: loaded classmap: test_dynamic_debug_submod [16..24] V0..V7
[ 18.866698] dyndbg: found kp:p_level_num =0x0
[ 18.866699] dyndbg: mapped to: test_dynamic_debug_submod [16..24] V0..V7
[ 18.866865] dyndbg: p_level_num: lvl:0 bits:0x0
[ 18.866926] dyndbg: loaded classmap: test_dynamic_debug_submod [0..10] D2_CORE..D2_DRMRES
[ 18.867026] dyndbg: found kp:p_disjoint_bits =0x0
[ 18.867027] dyndbg: mapped to: test_dynamic_debug_submod [0..10] D2_CORE..D2_DRMRES
[ 18.867193] dyndbg: p_disjoint_bits: classbits: 0x0
[ 18.867255] dyndbg: module:test_dynamic_debug_submod attached 2 classmap uses
[ 18.867351] dyndbg: 23 debug prints in module test_dynamic_debug_submod
fixup-test-submod
fixup-test
---
MAINTAINERS | 2 +-
include/asm-generic/vmlinux.lds.h | 1 +
include/linux/dynamic_debug.h | 107 +++++++++++++++++---
kernel/module/main.c | 3 +
lib/Kconfig.debug | 24 ++++-
lib/Makefile | 3 +
lib/dynamic_debug.c | 157 ++++++++++++++++++++++++------
lib/test_dynamic_debug.c | 132 ++++++++++++++++++-------
lib/test_dynamic_debug_submod.c | 14 +++
9 files changed, 354 insertions(+), 89 deletions(-)
create mode 100644 lib/test_dynamic_debug_submod.c
diff --git a/MAINTAINERS b/MAINTAINERS
index c9763412a508..f98aec07a46d 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8136,7 +8136,7 @@ M: Jim Cromie <jim.cromie@xxxxxxxxx>
S: Maintained
F: include/linux/dynamic_debug.h
F: lib/dynamic_debug.c
-F: lib/test_dynamic_debug.c
+F: lib/test_dynamic_debug*.c
DYNAMIC INTERRUPT MODERATION
M: Tal Gilboa <talgi@xxxxxxxxxx>
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index f834ad1fb8c4..fa382caf2ae2 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -367,6 +367,7 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
/* implement dynamic printk debug */ \
. = ALIGN(8); \
BOUNDED_SECTION_BY(__dyndbg_class_maps, ___dyndbg_class_maps) \
+ BOUNDED_SECTION_BY(__dyndbg_class_users, ___dyndbg_class_users) \
BOUNDED_SECTION_BY(__dyndbg_descriptors, ___dyndbg_descs) \
CODETAG_SECTIONS() \
LIKELY_PROFILE() \
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 9fb38d79216e..0e3e14ca4765 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -73,9 +73,28 @@ enum ddebug_class_map_type {
*/
};
-struct ddebug_class_map {
- struct module *mod;
- const char *mod_name; /* needed for builtins */
+/*
+ * dyndbg-classmaps are devised to support DRM.debug directly:
+ * 10 enum-vals: DRM_UT_* define the categories
+ * ~23 categorized *_dbg() macros, each passing a DRM_UT_* val as 1st arg
+ * 2 macros below them: drm_dev_dbg, __drm_dbg
+ * ~5000 calls to the categorized macros, across all of drivers/gpu/drm/
+ *
+ * When CONFIG_DRM_USE_DYNAMIC_DEBUG=y, the 2 low macros are redefined
+ * to invoke _dynamic_func_call_cls(). This compiles the category
+ * into each callsite's class_id field, where dyndbg can select on it
+ * and alter a callsite's patch-state, avoiding repeated __drm_debug
+ * checks.
+ *
+ * To make the callsites manageable from the >control file, authors
+ * provide a "classmap" of names to class_ids in use by the module(s),
+ * usually by stringifying the enum-vals. Modules with multiple
+ * classmaps must arrange to share the 0..62 class_id space.
+ */
+
+struct _ddebug_class_map {
+ const struct module *mod; /* NULL for builtins */
+ const char *mod_name;
const char **class_names;
const int length;
const int base; /* index of 1st .class_id, allows split/shared space */
@@ -83,16 +102,39 @@ struct ddebug_class_map {
};
/**
- * DECLARE_DYNDBG_CLASSMAP - declare classnames known by a module
- * @_var: a struct ddebug_class_map, passed to module_param_cb
- * @_type: enum class_map_type, chooses bits/verbose, numeric/symbolic
- * @_base: offset of 1st class-name. splits .class_id space
- * @classes: class-names used to control class'd prdbgs
+ * DYNAMIC_DEBUG_CLASSMAP_DEFINE - define debug classes used by a module.
+ * @_var: name of the classmap, exported for other modules coordinated use.
+ * @_mapty: enum ddebug_class_map_type: 0:DISJOINT - independent, 1:LEVEL - v2>v1
+ * @_base: reserve N classids starting at _base, to split 0..62 classid space
+ * @classes: names of the N classes.
+ *
+ * This tells dyndbg what class_ids the module is using: _base..+N, by
+ * mapping names onto them. This qualifies "class NAME" >controls on
+ * the defining module, ignoring unknown names.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_DEFINE(_var, _mapty, _base, ...) \
+ static const char *_var##_classnames[] = { __VA_ARGS__ }; \
+ extern struct _ddebug_class_map _var; \
+ struct _ddebug_class_map __aligned(8) __used \
+ __section("__dyndbg_class_maps") _var = { \
+ .mod = THIS_MODULE, \
+ .mod_name = KBUILD_MODNAME, \
+ .base = (_base), \
+ .map_type = (_mapty), \
+ .length = ARRAY_SIZE(_var##_classnames), \
+ .class_names = _var##_classnames, \
+ }; \
+ EXPORT_SYMBOL(_var)
+
+/*
+ * XXX: keep this until DRM adapts to use the DEFINE/USE api, it
+ * differs from DYNAMIC_DEBUG_CLASSMAP_DEFINE by the lack of the
+ * extern/EXPORT on the struct init, and cascading thinkos.
*/
#define DECLARE_DYNDBG_CLASSMAP(_var, _maptype, _base, ...) \
static const char *_var##_classnames[] = { __VA_ARGS__ }; \
- static struct ddebug_class_map __aligned(8) __used \
- __section("__dyndbg_classes") _var = { \
+ static struct _ddebug_class_map __aligned(8) __used \
+ __section("__dyndbg_class_maps") _var = { \
.mod = THIS_MODULE, \
.mod_name = KBUILD_MODNAME, \
.base = _base, \
@@ -101,31 +143,64 @@ struct ddebug_class_map {
.class_names = _var##_classnames, \
}
+struct _ddebug_class_user {
+ char *mod_name;
+ struct _ddebug_class_map *map;
+};
+
+/**
+ * DYNAMIC_DEBUG_CLASSMAP_USE - refer to a classmap, DEFINEd elsewhere.
+ * @_var: name of the exported classmap var
+ *
+ * This tells dyndbg that the module has prdbgs with classids defined
+ * in the named classmap. This qualifies "class NAME" >controls on
+ * the user module, ignoring unknown names.
+ */
+#define DYNAMIC_DEBUG_CLASSMAP_USE(_var) \
+ DYNAMIC_DEBUG_CLASSMAP_USE_(_var, __UNIQUE_ID(_ddebug_class_user))
+#define DYNAMIC_DEBUG_CLASSMAP_USE_(_var, _uname) \
+ extern struct _ddebug_class_map _var; \
+ static struct _ddebug_class_user __aligned(8) __used \
+ __section("__dyndbg_class_users") _uname = { \
+ .mod_name = KBUILD_MODNAME, \
+ .map = &(_var), \
+ }
+
/*
- * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
+ * @_ddebug_info: gathers module/builtin __dyndbg_<T> __sections
+ * together, each is a vector: a struct { <T> *addr, int len }.
+ *
* For builtins, it is used as a cursor, with the inner structs
- * marking sub-vectors of the builtin __sections in DATA.
+ * marking sub-vectors of the builtin __sections in DATA_DATA
*/
struct _ddebug_descs {
struct _ddebug *start;
int len;
} __packed;
+
struct _ddebug_class_maps {
- struct ddebug_class_map *start;
+ struct _ddebug_class_map *start;
int len;
} __packed;
+
+struct _ddebug_class_users {
+ struct _ddebug_class_user *start;
+ int len;
+} __packed;
+
struct _ddebug_info {
struct _ddebug_descs descs;
struct _ddebug_class_maps maps;
+ struct _ddebug_class_users users;
} __packed;
-struct ddebug_class_param {
+struct _ddebug_class_param {
union {
unsigned long *bits;
unsigned long *lvl;
};
char flags[8];
- const struct ddebug_class_map *map;
+ const struct _ddebug_class_map *map;
};
/*
@@ -217,7 +292,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* (|_no_desc): former gets callsite descriptor as 1st arg (for prdbgs)
*/
#define __dynamic_func_call_cls(id, cls, fmt, func, ...) do { \
- DEFINE_DYNAMIC_DEBUG_METADATA_CLS(id, cls, fmt); \
+ DEFINE_DYNAMIC_DEBUG_METADATA_CLS((id), cls, fmt); \
if (DYNAMIC_DEBUG_BRANCH(id)) \
func(&id, ##__VA_ARGS__); \
} while (0)
diff --git a/kernel/module/main.c b/kernel/module/main.c
index b60f728e36ac..c203b0694f7e 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2627,6 +2627,9 @@ static int find_module_sections(struct module *mod, struct load_info *info)
mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
sizeof(*mod->dyndbg_info.maps.start),
&mod->dyndbg_info.maps.len);
+ mod->dyndbg_info.users.start = section_objs(info, "__dyndbg_class_users",
+ sizeof(*mod->dyndbg_info.users.start),
+ &mod->dyndbg_info.users.len);
#endif
return 0;
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index 35796c290ca3..91a75f724c1a 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -2905,12 +2905,26 @@ config TEST_STATIC_KEYS
If unsure, say N.
config TEST_DYNAMIC_DEBUG
- tristate "Test DYNAMIC_DEBUG"
- depends on DYNAMIC_DEBUG
+ tristate "Build test-dynamic-debug module"
+ depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
help
- This module registers a tracer callback to count enabled
- pr_debugs in a 'do_debugging' function, then alters their
- enablements, calls the function, and compares counts.
+ This module exercises/demonstrates dyndbg's classmap API, by
+ creating 2 classes: a DISJOINT classmap (supporting DRM.debug)
+ and a LEVELS/VERBOSE classmap (like verbose2 > verbose1).
+
+ If unsure, say N.
+
+config TEST_DYNAMIC_DEBUG_SUBMOD
+ tristate "Build test-dynamic-debug submodule"
+ default m
+ depends on DYNAMIC_DEBUG || DYNAMIC_DEBUG_CORE
+ depends on TEST_DYNAMIC_DEBUG
+ help
+ This sub-module uses a classmap defined and exported by the
+ parent module, recapitulating drm & driver's shared use of
+ drm.debug to control enabled debug-categories.
+ It is tristate, independent of parent, to allow testing all
+ proper combinations of parent=y/m submod=y/m.
If unsure, say N.
diff --git a/lib/Makefile b/lib/Makefile
index d5cfc7afbbb8..2c344138d990 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -84,6 +84,7 @@ obj-$(CONFIG_TEST_SORT) += test_sort.o
obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_keys.o
obj-$(CONFIG_TEST_STATIC_KEYS) += test_static_key_base.o
obj-$(CONFIG_TEST_DYNAMIC_DEBUG) += test_dynamic_debug.o
+obj-$(CONFIG_TEST_DYNAMIC_DEBUG_SUBMOD) += test_dynamic_debug_submod.o
obj-$(CONFIG_TEST_PRINTF) += test_printf.o
obj-$(CONFIG_TEST_SCANF) += test_scanf.o
@@ -226,6 +227,8 @@ obj-$(CONFIG_ARCH_NEED_CMPXCHG_1_EMU) += cmpxchg-emu.o
obj-$(CONFIG_DYNAMIC_DEBUG_CORE) += dynamic_debug.o
#ensure exported functions have prototypes
CFLAGS_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug.o := -DDYNAMIC_DEBUG_MODULE
+CFLAGS_test_dynamic_debug_submod.o := -DDYNAMIC_DEBUG_MODULE
obj-$(CONFIG_SYMBOLIC_ERRNAME) += errname.o
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 5df9cc732290..aebafa1be06a 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -29,6 +29,7 @@
#include <linux/string_helpers.h>
#include <linux/uaccess.h>
#include <linux/dynamic_debug.h>
+
#include <linux/debugfs.h>
#include <linux/slab.h>
#include <linux/jump_label.h>
@@ -41,8 +42,10 @@
extern struct _ddebug __start___dyndbg_descs[];
extern struct _ddebug __stop___dyndbg_descs[];
-extern struct ddebug_class_map __start___dyndbg_class_maps[];
-extern struct ddebug_class_map __stop___dyndbg_class_maps[];
+extern struct _ddebug_class_map __start___dyndbg_class_maps[];
+extern struct _ddebug_class_map __stop___dyndbg_class_maps[];
+extern struct _ddebug_class_user __start___dyndbg_class_users[];
+extern struct _ddebug_class_user __stop___dyndbg_class_users[];
struct ddebug_table {
struct list_head link;
@@ -167,23 +170,28 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
_dt->info.users.len); \
})
-#define __outvar /* filled by callee */
-static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table const *dt,
- const char *class_string,
- __outvar int *class_id)
+static int ddebug_find_valid_class(struct ddebug_table const *dt, const char *class_string)
{
- struct ddebug_class_map *map;
+ struct _ddebug_class_map *map;
+ struct _ddebug_class_user *cli;
int i, idx;
for_subvec(i, map, &dt->info, maps) {
idx = match_string(map->class_names, map->length, class_string);
if (idx >= 0) {
- *class_id = idx + map->base;
- return map;
+ vpr_dt_info(dt, "good-class: %s.%s ", map->mod_name, class_string);
+ return idx + map->base;
}
}
- *class_id = -ENOENT;
- return NULL;
+ for_subvec(i, cli, &dt->info, users) {
+ idx = match_string(cli->map->class_names, cli->map->length, class_string);
+ if (idx >= 0) {
+ vpr_dt_info(dt, "class-ref: %s -> %s.%s ",
+ cli->mod_name, cli->map->mod_name, class_string);
+ return idx + cli->map->base;
+ }
+ }
+ return -ENOENT;
}
/*
@@ -192,16 +200,14 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
* callsites, normally the same as number of changes. If verbose,
* logs the changes. Takes ddebug_lock.
*/
-static int ddebug_change(const struct ddebug_query *query,
- struct flag_settings *modifiers)
+static int ddebug_change(const struct ddebug_query *query, struct flag_settings *modifiers)
{
int i;
struct ddebug_table *dt;
unsigned int newflags;
unsigned int nfound = 0;
struct flagsbuf fbuf, nbuf;
- struct ddebug_class_map *map = NULL;
- int __outvar valid_class;
+ int valid_class;
/* search for matching ddebugs */
mutex_lock(&ddebug_lock);
@@ -213,8 +219,8 @@ static int ddebug_change(const struct ddebug_query *query,
continue;
if (query->class_string) {
- map = ddebug_find_valid_class(dt, query->class_string, &valid_class);
- if (!map)
+ valid_class = ddebug_find_valid_class(dt, query->class_string);
+ if (valid_class < 0)
continue;
} else {
/* constrain query, do not touch class'd callsites */
@@ -578,7 +584,7 @@ static int ddebug_exec_query(char *query_string, const char *modname)
/* handle multiple queries in query string, continue on error, return
last error or number of matching callsites. Module name is either
- in param (for boot arg) or perhaps in query string.
+ in the modname arg (for boot args) or perhaps in query string.
*/
static int ddebug_exec_queries(char *query, const char *modname)
{
@@ -615,14 +621,14 @@ static int ddebug_exec_queries(char *query, const char *modname)
}
/* apply a new class-param setting */
-static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
+static int ddebug_apply_class_bitmap(const struct _ddebug_class_param *dcp,
const unsigned long *new_bits,
const unsigned long old_bits,
const char *query_modname)
{
#define QUERY_SIZE 128
char query[QUERY_SIZE];
- const struct ddebug_class_map *map = dcp->map;
+ const struct _ddebug_class_map *map = dcp->map;
int matches = 0;
int bi, ct;
@@ -659,8 +665,8 @@ static int param_set_dyndbg_module_classes(const char *instr,
const struct kernel_param *kp,
const char *modnm)
{
- const struct ddebug_class_param *dcp = kp->arg;
- const struct ddebug_class_map *map = dcp->map;
+ const struct _ddebug_class_param *dcp = kp->arg;
+ const struct _ddebug_class_map *map = dcp->map;
unsigned long inrep, new_bits, old_bits;
int rc, totct = 0;
char *nl;
@@ -709,7 +715,7 @@ static int param_set_dyndbg_module_classes(const char *instr,
/**
* param_set_dyndbg_classes - classmap kparam setter
* @instr: string echo>d to sysfs, input depends on map_type
- * @kp: kp->arg has state: bits/lvl, map, map_type
+ * @kp: kp->arg has state: bits/lvl, classmap, map_type
*
* enable/disable all class'd pr_debugs in the classmap. For LEVEL
* map-types, enforce * relative levels by bitpos.
@@ -735,8 +741,8 @@ EXPORT_SYMBOL(param_set_dyndbg_classes);
*/
int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
{
- const struct ddebug_class_param *dcp = kp->arg;
- const struct ddebug_class_map *map = dcp->map;
+ const struct _ddebug_class_param *dcp = kp->arg;
+ const struct _ddebug_class_map *map = dcp->map;
switch (map->map_type) {
case DD_CLASS_TYPE_DISJOINT_BITS:
@@ -746,6 +752,7 @@ int param_get_dyndbg_classes(char *buffer, const struct kernel_param *kp)
default:
return -1;
}
+ return 0;
}
EXPORT_SYMBOL(param_get_dyndbg_classes);
@@ -1067,13 +1074,18 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
{
- struct ddebug_class_map *map;
+ struct _ddebug_class_map *map;
+ struct _ddebug_class_user *cli;
int i;
for_subvec(i, map, &dt->info, maps)
if (class_in_range(dp->class_id, map))
return map->class_names[dp->class_id - map->base];
+ for_subvec(i, cli, &dt->info, users)
+ if (class_in_range(dp->class_id, cli->map))
+ return cli->map->class_names[dp->class_id - cli->map->base];
+
return NULL;
}
@@ -1154,9 +1166,85 @@ static const struct proc_ops proc_fops = {
.proc_write = ddebug_proc_write
};
-static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
+#define vpr_cm_info(cm_p, msg_fmt, ...) ({ \
+ struct _ddebug_class_map const *_cm = cm_p; \
+ v2pr_info(msg_fmt " %s [%d..%d] %s..%s\n", ##__VA_ARGS__, \
+ _cm->mod_name, _cm->base, _cm->base + _cm->length, \
+ _cm->class_names[0], _cm->class_names[_cm->length - 1]); \
+ })
+
+static void ddebug_sync_classbits(const struct kernel_param *kp, const char *modname)
+{
+ const struct _ddebug_class_param *dcp = kp->arg;
+
+ /* clamp initial bitvec, mask off hi-bits */
+ if (*dcp->bits & ~CLASSMAP_BITMASK(dcp->map->length)) {
+ *dcp->bits &= CLASSMAP_BITMASK(dcp->map->length);
+ v2pr_info("preset classbits: %lx\n", *dcp->bits);
+ }
+ /* force class'd prdbgs (in USEr module) to match (DEFINEr module) class-param */
+ ddebug_apply_class_bitmap(dcp, dcp->bits, ~0, modname);
+ ddebug_apply_class_bitmap(dcp, dcp->bits, 0, modname);
+}
+
+static void ddebug_match_apply_kparam(const struct kernel_param *kp,
+ const struct _ddebug_class_map *map,
+ const char *modnm)
{
- vpr_info("module:%s attached %d classes\n", dt->mod_name, dt->info.maps.len);
+ struct _ddebug_class_param *dcp;
+
+ if (kp->ops != ¶m_ops_dyndbg_classes)
+ return;
+
+ dcp = (struct _ddebug_class_param *)kp->arg;
+
+ if (map == dcp->map) {
+ v2pr_info(" kp:%s.%s =0x%lx", modnm, kp->name, *dcp->bits);
+ vpr_cm_info(map, " %s mapped to: ", modnm);
+ ddebug_sync_classbits(kp, modnm);
+ }
+}
+
+static void ddebug_apply_params(const struct _ddebug_class_map *cm, const char *modnm)
+{
+ const struct kernel_param *kp;
+#if IS_ENABLED(CONFIG_MODULES)
+ int i;
+
+ if (cm->mod) {
+ vpr_cm_info(cm, "loaded classmap: %s", modnm);
+ /* ifdef protects the cm->mod->kp deref */
+ for (i = 0, kp = cm->mod->kp; i < cm->mod->num_kp; i++, kp++)
+ ddebug_match_apply_kparam(kp, cm, modnm);
+ }
+#endif
+ if (!cm->mod) {
+ vpr_cm_info(cm, "builtin classmap: %s", modnm);
+ for (kp = __start___param; kp < __stop___param; kp++)
+ ddebug_match_apply_kparam(kp, cm, modnm);
+ }
+}
+
+static void ddebug_apply_class_maps(struct ddebug_table *dt)
+{
+ struct _ddebug_class_map *cm;
+ int i;
+
+ for_subvec(i, cm, &dt->info, maps)
+ ddebug_apply_params(cm, cm->mod_name);
+
+ vpr_dt_info(dt, "attached %d classmaps to module: %s ", i, cm->mod_name);
+}
+
+static void ddebug_apply_class_users(struct ddebug_table *dt)
+{
+ struct _ddebug_class_user *cli;
+ int i;
+
+ for_subvec(i, cli, &dt->info, users)
+ ddebug_apply_params(cli->map, cli->mod_name);
+
+ vpr_dt_info(dt, "attached %d class-users to module: %s ", i, cli->mod_name);
}
/*
@@ -1191,7 +1279,8 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
{
struct ddebug_table *dt;
- struct ddebug_class_map *cm;
+ struct _ddebug_class_map *cm;
+ struct _ddebug_class_user *cli;
int i;
if (!di->descs.len)
@@ -1221,14 +1310,18 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
* start,len of the vectors by mod_name, save to dt.
*/
dd_mark_vector_subrange(i, dt, cm, di, maps);
+ dd_mark_vector_subrange(i, dt, cli, di, users);
- if (di->maps.len)
- ddebug_attach_module_classes(dt, di);
+ if (dt->info.maps.len)
+ ddebug_apply_class_maps(dt);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
mutex_unlock(&ddebug_lock);
+ if (dt->info.users.len)
+ ddebug_apply_class_users(dt);
+
vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
return 0;
}
@@ -1378,8 +1471,10 @@ static int __init dynamic_debug_init(void)
struct _ddebug_info di = {
.descs.start = __start___dyndbg_descs,
.maps.start = __start___dyndbg_class_maps,
+ .users.start = __start___dyndbg_class_users,
.descs.len = __stop___dyndbg_descs - __start___dyndbg_descs,
.maps.len = __stop___dyndbg_class_maps - __start___dyndbg_class_maps,
+ .users.len = __stop___dyndbg_class_users - __start___dyndbg_class_users,
};
#ifdef CONFIG_MODULES
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 74d183ebf3e0..1070107f74f1 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -6,11 +6,30 @@
* Jim Cromie <jim.cromie@xxxxxxxxx>
*/
-#define pr_fmt(fmt) "test_dd: " fmt
+/*
+ * This file is built 2x, also making test_dynamic_debug_submod.ko,
+ * whose 2-line src file #includes this file. This gives us a _submod
+ * clone with identical pr_debugs, without further maintenance.
+ *
+ * If things are working properly, they should operate identically
+ * when printed or adjusted by >control. This eases visual perusal of
+ * the logs, and simplifies testing, by easing the proper accounting
+ * of expectations.
+ *
+ * It also puts both halves of the subsystem _DEFINE & _USE use case
+ * together, and integrates the common ENUM providing both class_ids
+ * and class-names to both _DEFINErs and _USERs. I think this makes
+ * the usage clearer.
+ */
+#if defined(TEST_DYNAMIC_DEBUG_SUBMOD)
+ #define pr_fmt(fmt) "test_dd_submod: " fmt
+#else
+ #define pr_fmt(fmt) "test_dd: " fmt
+#endif
#include <linux/module.h>
-/* run tests by reading or writing sysfs node: do_prints */
+/* re-gen output by reading or writing sysfs node: do_prints */
static void do_prints(void); /* device under test */
static int param_set_do_prints(const char *instr, const struct kernel_param *kp)
@@ -29,24 +48,39 @@ static const struct kernel_param_ops param_ops_do_prints = {
};
module_param_cb(do_prints, ¶m_ops_do_prints, NULL, 0600);
-/*
- * Using the CLASSMAP api:
- * - classmaps must have corresponding enum
- * - enum symbols must match/correlate with class-name strings in the map.
- * - base must equal enum's 1st value
- * - multiple maps must set their base to share the 0-30 class_id space !!
- * (build-bug-on tips welcome)
- * Additionally, here:
- * - tie together sysname, mapname, bitsname, flagsname
- */
-#define DD_SYS_WRAP(_model, _flags) \
- static unsigned long bits_##_model; \
- static struct ddebug_class_param _flags##_model = { \
+#define CLASSMAP_BITMASK(width, base) (((1UL << (width)) - 1) << (base))
+
+/* sysfs param wrapper, proto-API */
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, _init) \
+ static unsigned long bits_##_model = _init; \
+ static struct _ddebug_class_param _flags##_##_model = { \
.bits = &bits_##_model, \
.flags = #_flags, \
.map = &map_##_model, \
}; \
- module_param_cb(_flags##_##_model, ¶m_ops_dyndbg_classes, &_flags##_model, 0600)
+ module_param_cb(_flags##_##_model, ¶m_ops_dyndbg_classes, \
+ &_flags##_##_model, 0600)
+#ifdef DEBUG
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_model, _flags) \
+ DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, ~0)
+#else
+#define DYNAMIC_DEBUG_CLASSMAP_PARAM(_model, _flags) \
+ DYNAMIC_DEBUG_CLASSMAP_PARAM_(_model, _flags, 0)
+#endif
+
+/*
+ * Demonstrate/test DISJOINT & LEVEL typed classmaps with a sys-param.
+ *
+ * To comport with DRM debug-category (an int), classmaps map names to
+ * ids (also an int). So a classmap starts with an enum; DRM has enum
+ * debug_category: with DRM_UT_<CORE,DRIVER,KMS,etc>. We use the enum
+ * values as class-ids, and stringified enum-symbols as classnames.
+ *
+ * Modules with multiple CLASSMAPS must have enums with distinct
+ * value-ranges, as arranged below with explicit enum_sym = X inits.
+ * To clarify this sharing, declare the 2 enums now, for the 2
+ * different classmap types
+ */
/* numeric input, independent bits */
enum cat_disjoint_bits {
@@ -60,26 +94,51 @@ enum cat_disjoint_bits {
D2_LEASE,
D2_DP,
D2_DRMRES };
-DECLARE_DYNDBG_CLASSMAP(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS, 0,
- "D2_CORE",
- "D2_DRIVER",
- "D2_KMS",
- "D2_PRIME",
- "D2_ATOMIC",
- "D2_VBL",
- "D2_STATE",
- "D2_LEASE",
- "D2_DP",
- "D2_DRMRES");
-DD_SYS_WRAP(disjoint_bits, p);
-DD_SYS_WRAP(disjoint_bits, T);
-
-/* numeric verbosity, V2 > V1 related */
-enum cat_level_num { V0 = 14, V1, V2, V3, V4, V5, V6, V7 };
-DECLARE_DYNDBG_CLASSMAP(map_level_num, DD_CLASS_TYPE_LEVEL_NUM, 14,
- "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
-DD_SYS_WRAP(level_num, p);
-DD_SYS_WRAP(level_num, T);
+
+/* numeric verbosity, V2 > V1 related. V0 is > D2_DRM_RES */
+enum cat_level_num { V0 = 16, V1, V2, V3, V4, V5, V6, V7 };
+
+/* recapitulate DRM's multi-classmap setup */
+#if !defined(TEST_DYNAMIC_DEBUG_SUBMOD)
+/*
+ * In single user, or parent / coordinator (drm.ko) modules, define
+ * classmaps on the client enums above, and then declares the PARAMS
+ * ref'g the classmaps. Each is exported.
+ */
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_disjoint_bits, DD_CLASS_TYPE_DISJOINT_BITS,
+ D2_CORE,
+ "D2_CORE",
+ "D2_DRIVER",
+ "D2_KMS",
+ "D2_PRIME",
+ "D2_ATOMIC",
+ "D2_VBL",
+ "D2_STATE",
+ "D2_LEASE",
+ "D2_DP",
+ "D2_DRMRES");
+
+DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_level_num, DD_CLASS_TYPE_LEVEL_NUM,
+ V0, "V0", "V1", "V2", "V3", "V4", "V5", "V6", "V7");
+
+/*
+ * now add the sysfs-params
+ */
+
+DYNAMIC_DEBUG_CLASSMAP_PARAM(disjoint_bits, p);
+DYNAMIC_DEBUG_CLASSMAP_PARAM(level_num, p);
+
+#else /* TEST_DYNAMIC_DEBUG_SUBMOD */
+
+/*
+ * in submod/drm-drivers, use the classmaps defined in top/parent
+ * module above.
+ */
+
+DYNAMIC_DEBUG_CLASSMAP_USE(map_disjoint_bits);
+DYNAMIC_DEBUG_CLASSMAP_USE(map_level_num);
+
+#endif
/* stand-in for all pr_debug etc */
#define prdbg(SYM) __pr_debug_cls(SYM, #SYM " msg\n")
@@ -115,6 +174,7 @@ static void do_levels(void)
static void do_prints(void)
{
+ pr_debug("do_prints:\n");
do_cats();
do_levels();
}
diff --git a/lib/test_dynamic_debug_submod.c b/lib/test_dynamic_debug_submod.c
new file mode 100644
index 000000000000..672aabf40160
--- /dev/null
+++ b/lib/test_dynamic_debug_submod.c
@@ -0,0 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kernel module for testing dynamic_debug
+ *
+ * Authors:
+ * Jim Cromie <jim.cromie@xxxxxxxxx>
+ */
+
+/*
+ * clone the parent, inherit all the properties, for consistency and
+ * simpler accounting in test expectations.
+ */
+#define TEST_DYNAMIC_DEBUG_SUBMOD
+#include "test_dynamic_debug.c"
--
2.49.0
