Now that the DECLARE_DYNDBG_CLASSMAP macro has been split into
DYNDBG_CLASSMAP_DEFINE and DYNDBG_CLASSMAP_USE, lets differentiate
them according to their separate jobs.
Dyndbg's existing __dyndbg_classes[] section does:
. catalogs the classmaps defined by the module (or builtin modules)
. authorizes dyndbg to >control those class'd prdbgs for the module.
This patch adds __dyndbg_class_refs[] section:
. catalogs references/uses of the above classmap definitions.
. authorizes dyndbg to >control those class'd prdbgs in ref'g module.
. maps the client module to classmap definitions
drm-drivers and helpers are clients.
this allows dyndbg to apply drm.debug to the client module, when added.
The distinction of the 2 roles yields 2 gains:
It follows the define-once-declare-elsewhere pattern that K&R gave us,
dumping the weird coordinated-changes-by-identical-classmaps API.
It should help solve the chicken-egg problem that DRM_USE_DYNAMIC_DEBUG
has; the _USEr module must propagate the drm.debug setting once the
using module has loaded.
The new DYNDBG_CLASSMAP_* macros add records to the sections:
DYNDBG_CLASSMAP_DEFINE:
invoked just once per sub-system.
for drm, its drm_print, where drm.debug is exposed.
defines the classmap, names "DRM_UT_*", maps to class_id's
authorizes dyndbg to exert >control
populates __dyndbg_classes[] "section", __used.
exports the classmap.
DYNDBG_CLASSMAP_USE:
invoked by modules using classmaps defined & exported elsewhere
populates __dyndbg_class_refs[] "section", __used.
maps client-module name to the extern'd classmap.
has client-name, so dyndbg can recognize loading client modules.
also:
struct ddebug_info gets 2 new fields to encapsulate the new section:
class_refs, num_class_refs.
set by dynamic_debug_init() for builtins.
or by kernel/module/main:load_info() for loadable modules.
. struct ddebug_class_user
contains: user-module-name, ref to classmap-defn
dyndbg finds drm-driver's use of a classmap, gets/applies its settings
. vmlinux.lds.h additions: linker symbols, KEEP for new section
dynamic_debug.c: 2 sets of changes;
those "under" ddebug_add_module(), immediately below
those "under" ddebug_change(), further below
ddebug_attach_module_classes():
as before:
called from ddebug_add_module
finds classmaps whose .mod_name matches module being added.
attaches them to the module's ddebug_table.
ddebug_attach_client_module_classes():
new:
called from ddebug_add_module, after list-add to ddebug-tables.
like above, but works class-refs, not classes.
foreach __dyndbg_class_refs: ddebug_param_load_dependent_class(classmap*)
s/ddebug_find_kparams/ddebug_apply_parents_params/.
ddebug_find_kparam(classmap*):
scans module's/builtin kernel-params, calls ddebug_match_attach_kparam
for each to find the params/sysfs-nodes using a classmap.
ddebug_match_apply_kparam():
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.
Then compare the modname being loaded to the classmap.mod_name; if it
matches, save the debug_class_param into the classmap.dc_parm. This
lets users of the classmap (in particular a client) access the state.
ddebug_param_load_dependent_class():
Called from ddebug_attach_client_module_classes() on each class_refs[]
entry. Each user refs a classmap which has already been seen by
ddebug_find_kparam(), and whose .dc_parm has the state.
So this fn just copies the state to a local var, then calls
ddebug_apply_class_bitmap() to apply it to the dependent module.
ddebug_apply_class_bitmap() tests for bit changes before sending
messages without making changes.
ddebug_find_valid_class():
This helps ddebug_change(), doing the search over classmaps, looking
for the class given to >control. So now it searches over
__dyndbg_class_refs[] after __dyndbg_classes[].
Thats the theory anyway. things are still broken (differently) for
both builtins and loadables. For loadables, the >control is applied,
but doesnt alter any callsites. For builtins, things break earlier.
[*] consider swapping struct ddebug_class_param's dc_parm for kparam.
This gives access to kparam->name, helpful for current debugging.
Attaching that kp via macro would simplify attach-*module-classes too.
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
dyndbg: rework ddebug_(|client_)_module_attach_classes
move ddebug_attach_module_classes() up.
name-refinements++:
s/ddebug_param_load_dependent_class/ddebug_apply_parents_params/
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
---
include/asm-generic/vmlinux.lds.h | 3 +
include/linux/dynamic_debug.h | 39 ++++---
kernel/module/main.c | 2 +
lib/dynamic_debug.c | 166 ++++++++++++++++++++++++++----
4 files changed, 176 insertions(+), 34 deletions(-)
diff --git a/include/asm-generic/vmlinux.lds.h b/include/asm-generic/vmlinux.lds.h
index 3dc5824141cd..7100701fb68c 100644
--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -363,6 +363,9 @@
__start___dyndbg_classes = .; \
KEEP(*(__dyndbg_classes)) \
__stop___dyndbg_classes = .; \
+ __start___dyndbg_class_refs = .; \
+ KEEP(*(__dyndbg_class_refs)) \
+ __stop___dyndbg_class_refs = .; \
__start___dyndbg = .; \
KEEP(*(__dyndbg)) \
__stop___dyndbg = .; \
diff --git a/include/linux/dynamic_debug.h b/include/linux/dynamic_debug.h
index 1cdfd62fd2e4..397ac8294230 100644
--- a/include/linux/dynamic_debug.h
+++ b/include/linux/dynamic_debug.h
@@ -81,8 +81,8 @@ enum ddebug_class_map_type {
};
struct ddebug_class_map {
- struct module *mod;
- const char *mod_name; /* needed for builtins */
+ 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 */
@@ -99,8 +99,8 @@ struct ddebug_class_map {
* @classes: class-names used to control class'd prdbgs
*/
#define DYNDBG_CLASSMAP_DEFINE(_var, _maptype, _base, ...) \
- static const char *_var##_classnames[] = { __VA_ARGS__ }; \
- static struct ddebug_class_map __aligned(8) __used \
+ const char *_var##_classnames[] = { __VA_ARGS__ }; \
+ struct ddebug_class_map __aligned(8) __used \
__section("__dyndbg_classes") _var = { \
.mod = THIS_MODULE, \
.mod_name = KBUILD_MODNAME, \
@@ -108,24 +108,37 @@ struct ddebug_class_map {
.map_type = _maptype, \
.length = ARRAY_SIZE(_var##_classnames), \
.class_names = _var##_classnames, \
- }
+ }; \
+ EXPORT_SYMBOL(_var)
-/*
- * refer to the classmap instantiated once, by the macro above. This
- * distinguishes the multiple users of drm.debug from the single
- * definition, allowing them to specialize. ATM its a pass-thru, but
- * it should help regularize the admittedly wierd sharing by identical
- * definitions.
+struct ddebug_class_user {
+ char *user_mod_name;
+ struct ddebug_class_map *map;
+};
+/**
+ * DYNDBG_CLASSMAP_USE - Use a classmap DEFINEd in another module.
+ * This lets dyndbg initialize the dependent module's prdbgs from the
+ * other module's controlling sysfs node.
*/
-#define DYNDBG_CLASSMAP_USE(_var, _maptype, _base, ...) \
- DYNDBG_CLASSMAP_DEFINE(_var, _maptype, _base, __VA_ARGS__)
+#define DYNDBG_CLASSMAP_USE(_var, ...) \
+ DYNDBG_CLASSMAP_USE_(_var, __UNIQUE_ID(ddebug_class_user), \
+ __VA_ARGS__)
+#define DYNDBG_CLASSMAP_USE_(_var, _uname, ...) \
+ extern struct ddebug_class_map _var; \
+ static struct ddebug_class_user __used \
+ __section("__dyndbg_class_refs") _uname = { \
+ .user_mod_name = KBUILD_MODNAME, \
+ .map = &_var, \
+ }
/* encapsulate linker provided built-in (or module) dyndbg data */
struct _ddebug_info {
struct _ddebug *descs;
struct ddebug_class_map *classes;
+ struct ddebug_class_user *class_refs;
unsigned int num_descs;
unsigned int num_classes;
+ unsigned int num_class_refs;
};
struct ddebug_class_param {
diff --git a/kernel/module/main.c b/kernel/module/main.c
index d02d39c7174e..ee4f85a3b8f0 100644
--- a/kernel/module/main.c
+++ b/kernel/module/main.c
@@ -2111,6 +2111,8 @@ static int find_module_sections(struct module *mod, struct load_info *info)
sizeof(*info->dyndbg.descs), &info->dyndbg.num_descs);
info->dyndbg.classes = section_objs(info, "__dyndbg_classes",
sizeof(*info->dyndbg.classes), &info->dyndbg.num_classes);
+ info->dyndbg.class_refs = section_objs(info, "__dyndbg_class_refs",
+ sizeof(*info->dyndbg.class_refs), &info->dyndbg.num_class_refs);
return 0;
}
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index b51f4bde6198..19bf66229d45 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -43,13 +43,16 @@ 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_class_user __start___dyndbg_class_refs[];
+extern struct ddebug_class_user __stop___dyndbg_class_refs[];
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_class_user *class_refs;
+ unsigned int num_ddebugs, num_classes, num_class_refs;
};
struct ddebug_query {
@@ -147,21 +150,36 @@ 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, _msg, ...) \
+ v2pr_info(_msg " module:%s nd:%d nc:%d nu:%d\n", ##__VA_ARGS__, \
+ dt->mod_name, dt->num_ddebugs, dt->num_classes, dt->num_class_refs);
+
#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)
{
struct ddebug_class_map *map;
+ struct ddebug_class_user *cli;
int i, idx;
- for (map = dt->classes, i = 0; i < dt->num_classes; i++, map++) {
+ for (i = 0, map = dt->classes; i < dt->num_classes; i++, map++) {
idx = match_string(map->class_names, map->length, class_string);
if (idx >= 0) {
*class_id = idx + map->base;
+ vpr_dt_info(dt, "good-class: %s.%s ", map->mod_name, class_string);
return map;
}
}
+ for (i = 0, cli = dt->class_refs; i < dt->num_class_refs; i++, cli++) {
+ idx = match_string(cli->map->class_names, cli->map->length, class_string);
+ if (idx >= 0) {
+ *class_id = idx + cli->map->base;
+ vpr_dt_info(dt, "class-ref: %s.%s ",
+ cli->user_mod_name, class_string);
+ return cli->map;
+ }
+ }
*class_id = -ENOENT;
return NULL;
}
@@ -590,9 +608,10 @@ static int ddebug_exec_queries(char *query, const char *modname)
return nfound;
}
-/* apply a new bitmap to the sys-knob's current bit-state */
+/* apply a new class-param setting */
static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
- const unsigned long *new_bits, const unsigned long *old_bits,
+ const unsigned long *new_bits,
+ const unsigned long *old_bits,
const char *query_modname)
{
#define QUERY_SIZE 128
@@ -601,8 +620,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
int matches = 0;
int bi, ct;
- v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
- query_modname ?: "");
+ if (*new_bits != *old_bits)
+ v2pr_info("apply bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+ *old_bits, query_modname ?: "'*'");
for (bi = 0; bi < map->length; bi++) {
if (test_bit(bi, new_bits) == test_bit(bi, old_bits))
@@ -617,8 +637,9 @@ static int ddebug_apply_class_bitmap(const struct ddebug_class_param *dcp,
v2pr_info("bit_%d: %d matches on class: %s -> 0x%lx\n", bi,
ct, map->class_names[bi], *new_bits);
}
- v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits, *old_bits,
- query_modname ?: "");
+ if (*new_bits != *old_bits)
+ v2pr_info("applied bitmap: 0x%lx to: 0x%lx for %s\n", *new_bits,
+ *old_bits, query_modname ?: "'*'");
return matches;
}
@@ -720,7 +741,10 @@ static int param_set_dyndbg_module_classes(const char *instr,
/* numeric input, accept and fall-thru */
rc = kstrtoul(instr, 0, &inrep);
if (rc) {
- pr_err("expecting numeric input: %s > %s\n", instr, KP_NAME(kp));
+ char *nl = strchr(instr, '\n');
+ if (nl)
+ *nl = '\0';
+ pr_err("expecting numeric input, not: %s > %s\n", instr, KP_NAME(kp));
return -EINVAL;
}
break;
@@ -1113,12 +1137,17 @@ 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 = dt->classes;
+ struct ddebug_class_user *cli = dt->class_refs;
int i;
for (i = 0; i < dt->num_classes; i++, map++)
if (class_in_range(dp->class_id, map))
return map->class_names[dp->class_id - map->base];
+ for (i = 0; i < dt->num_class_refs; i++, cli++)
+ if (class_in_range(dp->class_id, cli->map))
+ return cli->map->class_names[dp->class_id - cli->map->base];
+
return NULL;
}
@@ -1199,31 +1228,120 @@ static const struct proc_ops proc_fops = {
.proc_write = ddebug_proc_write
};
+
+/*
+ * Find this module's classmaps in a sub/whole-range of the builtin/
+ * modular classmap vector/section. Save the start and length of the
+ * subrange at its edges.
+ */
static void ddebug_attach_module_classes(struct ddebug_table *dt, struct _ddebug_info *di)
{
struct ddebug_class_map *cm;
int i, nc = 0;
- /*
- * Find this module's classmaps in a subrange/wholerange of
- * the builtin/modular classmap vector/section. Save the start
- * and length of the subrange at its edges.
- */
- for (cm = di->classes, i = 0; i < di->num_classes; i++, cm++) {
+ for (i = 0, cm = di->classes; i < di->num_classes; i++, cm++) {
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;
+ v2pr_info("classes[0..]: module:%s base:%d len:%d ty:%d\n",
+ cm->mod_name, cm->base, cm->length, cm->map_type);
}
nc++;
}
}
- if (nc) {
- dt->num_classes = nc;
+ dt->num_classes = nc;
+ if (nc)
vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
+}
+
+#define vpr_cm_info(cm, _msg, ...) \
+ v2pr_info(_msg "module:%s base:%d len:%d type:%d\n", ##__VA_ARGS__, \
+ cm->mod_name, cm->base, cm->length, cm->map_type)
+
+static void ddebug_match_apply_kparam(const struct kernel_param *kp,
+ const struct ddebug_class_map *cm,
+ const char *cli_name)
+{
+ struct ddebug_class_param *dcp;
+ unsigned long new_bits, old_bits = 0;
+ int totct = 0;
+
+ if (kp->ops != ¶m_ops_dyndbg_classes)
+ return;
+
+ dcp = (struct ddebug_class_param *)kp->arg;
+
+ if (cm == dcp->map) {
+ v2pr_info("found kp:%s =0x%lx", kp->name, *dcp->bits);
+ vpr_cm_info(cm, "mapped to:");
+ /*
+ * using apply-bitmap is too low.
+ * param_set_dyndbg_classes uses map_type to sort
+ * levels-to-bits.
+ * param_set_dyndbg_classes is too high, it takes
+ * string inputs.
+ * de-union-ing levels/bits might solve it (partly),
+ * at least simplifying the translation, and possibly
+ * the apply-bitmap fn/iface
+ */
+ new_bits = *dcp->bits;
+ totct += ddebug_apply_class_bitmap(dcp, &new_bits, &old_bits, cli_name);
+ }
+}
+
+static void ddebug_apply_parents_params(const struct ddebug_class_map *cm,
+ const char *user_modname)
+{
+ const struct kernel_param *kp;
+#if IS_ENABLED(CONFIG_MODULES)
+ int i;
+
+ if (cm->mod) {
+ vpr_cm_info(cm, "loaded class:");
+ for (i = 0, kp = cm->mod->kp; i < cm->mod->num_kp; i++, kp++)
+ ddebug_match_apply_kparam(kp, cm, user_modname);
+ }
+#endif
+ if (!cm->mod) {
+ vpr_cm_info(cm, "builtin class:");
+ for (kp = __start___param; kp < __stop___param; kp++)
+ ddebug_match_apply_kparam(kp, cm, user_modname);
+ }
+}
+
+/*
+ * propagates class-params thru their classmaps to class-users. this
+ * means a query against the dt/module, which means it must be on the
+ * list to be seen by ddebug_change.
+ */
+static void ddebug_attach_client_module_classes(struct ddebug_table *dt, const struct _ddebug_info *di)
+{
+ struct ddebug_class_user *cli;
+ const struct ddebug_class_map *cm;
+ int i, nc = 0;
+
+ for (i = 0, cli = di->class_refs; i < di->num_class_refs; i++, cli++) {
+
+ BUG_ON(!cli || !cli->map || !cli->user_mod_name);
+
+ if (!strcmp(cli->user_mod_name, dt->mod_name)) {
+
+ v2pr_info("class_ref[%d] %s -> %s\n", i,
+ cli->user_mod_name, cli->map->mod_name);
+
+ if (!nc++)
+ dt->class_refs = cli;
+ }
+ }
+ dt->num_class_refs = nc;
+
+ for (i = 0, cli = dt->class_refs; i < dt->num_class_refs; i++, cli++) {
+ cm = cli->map;
+ ddebug_apply_parents_params(cm, cli->user_mod_name);
}
+
+ vpr_dt_info(dt, "attach-client-module: ");
}
/*
@@ -1235,7 +1353,8 @@ static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
{
struct ddebug_table *dt;
- v3pr_info("add-module: %s.%d sites\n", modname, di->num_descs);
+ v3pr_info("add-module: %s %d sites %d.%d\n", modname, di->num_descs,
+ di->num_classes, di->num_class_refs);
if (!di->num_descs) {
v3pr_info(" skip %s\n", modname);
return 0;
@@ -1258,13 +1377,16 @@ static int __ddebug_add_module(struct _ddebug_info *di, unsigned int base,
INIT_LIST_HEAD(&dt->link);
- if (di->classes && di->num_classes)
+ if (di->num_classes)
ddebug_attach_module_classes(dt, di);
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
mutex_unlock(&ddebug_lock);
+ if (di->num_class_refs)
+ ddebug_attach_client_module_classes(dt, di);
+
vpr_info("%3u debug prints in module %s\n", di->num_descs, modname);
return 0;
}
@@ -1390,8 +1512,10 @@ static int __init dynamic_debug_init(void)
struct _ddebug_info di = {
.descs = __start___dyndbg,
.classes = __start___dyndbg_classes,
+ .class_refs = __start___dyndbg_class_refs,
.num_descs = __stop___dyndbg - __start___dyndbg,
.num_classes = __stop___dyndbg_classes - __start___dyndbg_classes,
+ .num_class_refs = __stop___dyndbg_class_refs - __start___dyndbg_class_refs,
};
if (&__start___dyndbg == &__stop___dyndbg) {
--
2.39.0
