[PATCH v2 12/59] dyndbg, module: make proper substructs in _ddebug_info
Jim Cromie
jim.cromie at gmail.com
Thu Mar 20 18:51:50 UTC 2025
recompose struct _ddebug_info, inserting proper sub-structs.
The struct currently has 2 pairs of fields: descs, num_descs and
classes, num_classes. Several for-loops operate on these field pairs,
soon many more will be added.
Looping over these blocks by respective field-pairs is repetitive and
fiddly, differing only by the field-names. Before adding a 3rd
section and compounding the fiddly details problem, make proper
substructs of each section, with the same named fields.
So this patch does:
Adds 3 "vector<T>" structs, each with { <T> *start, int len; }
components, for _ddebug_descriptors, _ddebug_class_maps, and
_ddebug_class_users respectively.
Invariant: These vectors ref a contiguous subrange of __section memory
in builtin/DATA or in loadable modules via mod->dyndbg_info; with
guaranteed life-time for us.
Bundles these 3 vectors (subrange-refs) struct (reformed) _ddebug_info,
where they're __packed to close the paholes introduced otherwise.
The common fields allow improving the for_subvec() macro by dropping
the ugly num_##<T> paste-up.
Also recompose struct ddebug_table to contain a _ddebug_info. This
reinforces its use as a cursor into relevant data for a builtin
module, and access to the full _ddebug state for modules.
NOTES:
Fixup names: section names improved, struct names normalized to
_ddebug_*
struct module contains a _ddebug_info field and module/main.c sets it
up, so that gets adjusted.
The __packed attribute on _ddebug_info and the 3 contained structs
closes the holes otherwise created by the structification (which was
my excuse for not doing it originally).
Signed-off-by: Jim Cromie <jim.cromie at gmail.com>
---
-v2 rework towards front of series
---
include/asm-generic/vmlinux.lds.h | 4 +-
include/linux/dynamic_debug.h | 28 +++++++---
kernel/module/main.c | 12 ++--
lib/dynamic_debug.c | 91 ++++++++++++++++---------------
4 files changed, 74 insertions(+), 61 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index c9c66089ea2f..f834ad1fb8c4 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -366,8 +366,8 @@ defined(CONFIG_AUTOFDO_CLANG) || defined(CONFIG_PROPELLER_CLANG)
*(__tracepoints) \
/* implement dynamic printk debug */ \
. = ALIGN(8); \
- BOUNDED_SECTION_BY(__dyndbg_classes, ___dyndbg_classes) \
- BOUNDED_SECTION_BY(__dyndbg, ___dyndbg) \
+ BOUNDED_SECTION_BY(__dyndbg_class_maps, ___dyndbg_class_maps) \
+ BOUNDED_SECTION_BY(__dyndbg_descriptors, ___dyndbg_descs) \
CODETAG_SECTIONS() \
LIKELY_PROFILE() \
BRANCH_PROFILE() \
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index e458d4b838ac..c388ab05a6e1 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -110,13 +110,23 @@ struct ddebug_class_map {
.class_names = _var##_classnames, \
}
-/* encapsulate linker provided built-in (or module) dyndbg data */
+/*
+ * @_ddebug_info: gathers module/builtin dyndbg_* __sections together.
+ * For builtins, it is used as a cursor, with the inner structs
+ * marking sub-vectors of the builtin __sections in DATA.
+ */
+struct _ddebug_descs {
+ struct _ddebug *start;
+ int len;
+} __packed;
+struct _ddebug_class_maps {
+ struct ddebug_class_map *start;
+ int len;
+} __packed;
struct _ddebug_info {
- struct _ddebug *descs;
- struct ddebug_class_map *classes;
- unsigned int num_descs;
- unsigned int num_classes;
-};
+ struct _ddebug_descs descs;
+ struct _ddebug_class_maps maps;
+} __packed;
struct ddebug_class_param {
union {
@@ -159,7 +169,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
#define DEFINE_DYNAMIC_DEBUG_METADATA_CLS(name, cls, fmt) \
static struct _ddebug __aligned(8) \
- __section("__dyndbg") name = { \
+ __section("__dyndbg_descriptors") name = { \
.modname = KBUILD_MODNAME, \
.function = __func__, \
.filename = __FILE__, \
@@ -242,7 +252,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* macro.
*/
#define _dynamic_func_call_cls(cls, fmt, func, ...) \
- __dynamic_func_call_cls(__UNIQUE_ID(ddebug), cls, fmt, func, ##__VA_ARGS__)
+ __dynamic_func_call_cls(__UNIQUE_ID(_ddebug), cls, fmt, func, ##__VA_ARGS__)
#define _dynamic_func_call(fmt, func, ...) \
_dynamic_func_call_cls(_DPRINTK_CLASS_DFLT, fmt, func, ##__VA_ARGS__)
@@ -252,7 +262,7 @@ void __dynamic_ibdev_dbg(struct _ddebug *descriptor,
* with precisely the macro's varargs.
*/
#define _dynamic_func_call_cls_no_desc(cls, fmt, func, ...) \
- __dynamic_func_call_cls_no_desc(__UNIQUE_ID(ddebug), cls, fmt, \
+ __dynamic_func_call_cls_no_desc(__UNIQUE_ID(_ddebug), cls, fmt, \
func, ##__VA_ARGS__)
#define _dynamic_func_call_no_desc(fmt, func, ...) \
_dynamic_func_call_cls_no_desc(_DPRINTK_CLASS_DFLT, fmt, \
diff --git a/kernel/module/main.c b/kernel/module/main.c
index 1fb9ad289a6f..b60f728e36ac 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2621,12 +2621,12 @@ static int find_module_sections(struct module *mod, struct load_info *info)
pr_warn("%s: Ignoring obsolete parameters\n", mod->name);
#ifdef CONFIG_DYNAMIC_DEBUG_CORE
- mod->dyndbg_info.descs = section_objs(info, "__dyndbg",
- sizeof(*mod->dyndbg_info.descs),
- &mod->dyndbg_info.num_descs);
- mod->dyndbg_info.classes = section_objs(info, "__dyndbg_classes",
- sizeof(*mod->dyndbg_info.classes),
- &mod->dyndbg_info.num_classes);
+ mod->dyndbg_info.descs.start = section_objs(info, "__dyndbg_descriptors",
+ sizeof(*mod->dyndbg_info.descs.start),
+ &mod->dyndbg_info.descs.len);
+ mod->dyndbg_info.maps.start = section_objs(info, "__dyndbg_class_maps",
+ sizeof(*mod->dyndbg_info.maps.start),
+ &mod->dyndbg_info.maps.len);
#endif
return 0;
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 94f6c8fd787b..663c125006d0 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -39,17 +39,15 @@
#include <rdma/ib_verbs.h>
-extern struct _ddebug __start___dyndbg[];
-extern struct _ddebug __stop___dyndbg[];
-extern struct ddebug_class_map __start___dyndbg_classes[];
-extern struct ddebug_class_map __stop___dyndbg_classes[];
+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[];
struct ddebug_table {
struct list_head link;
const char *mod_name;
- struct _ddebug *ddebugs;
- struct ddebug_class_map *classes;
- unsigned int num_ddebugs, num_classes;
+ struct _ddebug_info info;
};
struct ddebug_query {
@@ -128,7 +126,6 @@ do { \
#define v3pr_info(fmt, ...) vnpr_info(3, fmt, ##__VA_ARGS__)
#define v4pr_info(fmt, ...) vnpr_info(4, fmt, ##__VA_ARGS__)
-
/*
* simplify a repeated for-loop pattern walking N steps in a T _vec
* member inside a struct _box. It expects int i and T *_sp to be
@@ -139,8 +136,8 @@ do { \
* @_vec: name of a sub-struct member in _box, with array-ref and length
*/
#define for_subvec(_i, _sp, _box, _vec) \
- for ((_i) = 0, (_sp) = (_box)->_vec; \
- (_i) < (_box)->num_##_vec; \
+ for ((_i) = 0, (_sp) = (_box)->_vec.start; \
+ (_i) < (_box)->_vec.len; \
(_i)++, (_sp)++)
static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
@@ -163,6 +160,13 @@ static void vpr_info_dq(const struct ddebug_query *query, const char *msg)
query->first_lineno, query->last_lineno, query->class_string);
}
+#define vpr_dt_info(dt_p, msg_p, ...) ({ \
+ struct ddebug_table const *_dt = dt_p; \
+ v2pr_info(msg_p " module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \
+ _dt->mod_name, _dt->info.descs.len, _dt->info.maps.len, \
+ _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,
@@ -171,7 +175,7 @@ static struct ddebug_class_map *ddebug_find_valid_class(struct ddebug_table cons
struct ddebug_class_map *map;
int i, idx;
- for_subvec(i, map, dt, classes) {
+ 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;
@@ -217,8 +221,8 @@ static int ddebug_change(const struct ddebug_query *query,
valid_class = _DPRINTK_CLASS_DFLT;
}
- for (i = 0; i < dt->num_ddebugs; i++) {
- struct _ddebug *dp = &dt->ddebugs[i];
+ for (i = 0; i < dt->info.descs.len; i++) {
+ struct _ddebug *dp = &dt->info.descs.start[i];
/* match site against query-class */
if (dp->class_id != valid_class)
@@ -1065,8 +1069,8 @@ static struct _ddebug *ddebug_iter_first(struct ddebug_iter *iter)
}
iter->table = list_entry(ddebug_tables.next,
struct ddebug_table, link);
- iter->idx = iter->table->num_ddebugs;
- return &iter->table->ddebugs[--iter->idx];
+ iter->idx = iter->table->info.descs.len;
+ return &iter->table->info.descs.start[--iter->idx];
}
/*
@@ -1087,10 +1091,10 @@ static struct _ddebug *ddebug_iter_next(struct ddebug_iter *iter)
}
iter->table = list_entry(iter->table->link.next,
struct ddebug_table, link);
- iter->idx = iter->table->num_ddebugs;
+ iter->idx = iter->table->info.descs.len;
--iter->idx;
}
- return &iter->table->ddebugs[iter->idx];
+ return &iter->table->info.descs.start[iter->idx];
}
/*
@@ -1137,12 +1141,12 @@ static void *ddebug_proc_next(struct seq_file *m, void *p, loff_t *pos)
#define class_in_range(class_id, map) \
(class_id >= map->base && class_id < map->base + map->length)
-static const char *ddebug_class_name(struct ddebug_iter *iter, struct _ddebug *dp)
+static const char *ddebug_class_name(struct ddebug_table *dt, struct _ddebug *dp)
{
- struct ddebug_class_map *map = iter->table->classes;
- int i, nc = iter->table->num_classes;
+ struct ddebug_class_map *map;
+ int i;
- for (i = 0; i < nc; i++, map++)
+ for_subvec(i, map, &dt->info, maps)
if (class_in_range(dp->class_id, map))
return map->class_names[dp->class_id - map->base];
@@ -1176,7 +1180,7 @@ static int ddebug_proc_show(struct seq_file *m, void *p)
seq_putc(m, '"');
if (dp->class_id != _DPRINTK_CLASS_DFLT) {
- class = ddebug_class_name(iter, dp);
+ class = ddebug_class_name(iter->table, dp);
if (class)
seq_printf(m, " class:%s", class);
else
@@ -1236,18 +1240,18 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug
* the builtin/modular classmap vector/section. Save the start
* and length of the subrange at its edges.
*/
- for_subvec(i, cm, di, classes) {
+ for_subvec(i, cm, di, maps) {
if (!strcmp(cm->mod_name, dt->mod_name)) {
if (!nc) {
v2pr_info("start subrange, class[%d]: module:%s base:%d len:%d ty:%d\n",
i, cm->mod_name, cm->base, cm->length, cm->map_type);
- dt->classes = cm;
+ dt->info.maps.start = cm;
}
nc++;
}
}
if (nc) {
- dt->num_classes = nc;
+ dt->info.maps.len = nc;
vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
}
}
@@ -1260,10 +1264,10 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
{
struct ddebug_table *dt;
- if (!di->num_descs)
+ if (!di->descs.len)
return 0;
- v3pr_info("add-module: %s %d sites\n", modname, di->num_descs);
+ v3pr_info("add-module: %s %d sites\n", modname, di->descs.len);
dt = kzalloc(sizeof(*dt), GFP_KERNEL);
if (dt == NULL) {
@@ -1277,19 +1281,18 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
* this struct ddebug_table.
*/
dt->mod_name = modname;
- dt->ddebugs = di->descs;
- dt->num_ddebugs = di->num_descs;
+ dt->info = *di;
INIT_LIST_HEAD(&dt->link);
- if (di->classes && di->num_classes)
+ if (di->maps.len)
ddebug_attach_module_classes(dt, di);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
mutex_unlock(&ddebug_lock);
- vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
+ vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
return 0;
}
@@ -1436,10 +1439,10 @@ static int __init dynamic_debug_init(void)
char *cmdline;
struct _ddebug_info di = {
- .descs = __start___dyndbg,
- .classes = __start___dyndbg_classes,
- .num_descs = __stop___dyndbg - __start___dyndbg,
- .num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+ .descs.start = __start___dyndbg_descs,
+ .maps.start = __start___dyndbg_class_maps,
+ .descs.len = __stop___dyndbg_descs - __start___dyndbg_descs,
+ .maps.len = __stop___dyndbg_class_maps - __start___dyndbg_class_maps,
};
#ifdef CONFIG_MODULES
@@ -1450,7 +1453,7 @@ static int __init dynamic_debug_init(void)
}
#endif /* CONFIG_MODULES */
- if (&__start___dyndbg == &__stop___dyndbg) {
+ if (&__start___dyndbg_descs == &__stop___dyndbg_descs) {
if (IS_ENABLED(CONFIG_DYNAMIC_DEBUG)) {
pr_warn("_ddebug table is empty in a CONFIG_DYNAMIC_DEBUG build\n");
return 1;
@@ -1460,16 +1463,16 @@ static int __init dynamic_debug_init(void)
return 0;
}
- iter = iter_mod_start = __start___dyndbg;
+ iter = iter_mod_start = __start___dyndbg_descs;
modname = iter->modname;
i = mod_sites = mod_ct = 0;
- for (; iter < __stop___dyndbg; iter++, i++, mod_sites++) {
+ for (; iter < __stop___dyndbg_descs; iter++, i++, mod_sites++) {
if (strcmp(modname, iter->modname)) {
mod_ct++;
- di.num_descs = mod_sites;
- di.descs = iter_mod_start;
+ di.descs.len = mod_sites;
+ di.descs.start = iter_mod_start;
ret = ddebug_add_module(&di, modname);
if (ret)
goto out_err;
@@ -1479,8 +1482,8 @@ static int __init dynamic_debug_init(void)
iter_mod_start = iter;
}
}
- di.num_descs = mod_sites;
- di.descs = iter_mod_start;
+ di.descs.len = mod_sites;
+ di.descs.start = iter_mod_start;
ret = ddebug_add_module(&di, modname);
if (ret)
goto out_err;
@@ -1490,8 +1493,8 @@ static int __init dynamic_debug_init(void)
i, mod_ct, (int)((mod_ct * sizeof(struct ddebug_table)) >> 10),
(int)((i * sizeof(struct _ddebug)) >> 10));
- if (di.num_classes)
- v2pr_info(" %d builtin ddebug class-maps\n", di.num_classes);
+ if (di.maps.len)
+ v2pr_info(" %d builtin ddebug class-maps\n", di.maps.len);
/* now that ddebug tables are loaded, process all boot args
* again to find and activate queries given in dyndbg params.
--
2.49.0
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