Le 25/01/2025 à 07:45, Jim Cromie a écrit :
To prep for failing modprobe on classid conflicts, upgrade the
call-chain around ddebug_add_module(), in 2 ways:
1. in ddebug_add_module() add local reserved_ids to accumulate
reservations, pass it by ref to ddebug_attach_{,user_}module_classes()
so they can examine the reservations as they work.
2. return int from both ddebug_attach_{,user_}module_classes(), up to
ddebug_add_module(), then to ddebug_module_notify().
No conflicts are currently detected or returned.
TBD: This is updated further by hoisting the reservation-check, which
obsoletes part of 2, creating churn, maybe squash it away.
Hi Jim,
It could be very nice to squash when possible yes!
Signed-off-by: Jim Cromie <jim.cromie@xxxxxxxxx>
Reviewed-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>
---
lib/dynamic_debug.c | 40 +++++++++++++++++++++++++++++-----------
1 file changed, 29 insertions(+), 11 deletions(-)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 16c9b752822b..0ef243e30663 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1216,8 +1216,9 @@ static void ddebug_apply_params(const struct ddebug_class_map *cm, const char *m
* 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,
- const struct _ddebug_info *di)
+static int ddebug_attach_module_classes(struct ddebug_table *dt,
+ const struct _ddebug_info *di,
+ u64 *reserved_ids)
{
struct ddebug_class_map *cm;
int i, nc = 0;
@@ -1230,13 +1231,14 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt,
}
}
if (!nc)
- return;
+ return 0;
vpr_info("module:%s attached %d classes\n", dt->mod_name, nc);
dt->info.maps.len = nc;
for_subvec(i, cm, &dt->info, maps)
ddebug_apply_params(cm, cm->mod_name);
+ return 0;
}
/*
@@ -1244,8 +1246,9 @@ static void ddebug_attach_module_classes(struct ddebug_table *dt,
* 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_user_module_classes(struct ddebug_table *dt,
- const struct _ddebug_info *di)
+static int ddebug_attach_user_module_classes(struct ddebug_table *dt,
+ const struct _ddebug_info *di,
+ u64 *reserved_ids)
{
struct ddebug_class_user *cli;
int i, nc = 0;
@@ -1266,7 +1269,7 @@ static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
}
}
if (!nc)
- return;
+ return 0;
dt->info.users.len = nc;
@@ -1275,6 +1278,7 @@ static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
ddebug_apply_params(cli->map, cli->mod_name);
vpr_dt_info(dt, "attach-client-module: ");
+ return 0;
}
/*
@@ -1284,6 +1288,8 @@ static void ddebug_attach_user_module_classes(struct ddebug_table *dt,
static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
{
struct ddebug_table *dt;
+ u64 reserved_ids = 0;
+ int rc;
if (!di->descs.len)
return 0;
@@ -1306,16 +1312,23 @@ static int ddebug_add_module(struct _ddebug_info *di, const char *modname)
INIT_LIST_HEAD(&dt->link);
- if (di->maps.len)
- ddebug_attach_module_classes(dt, di);
-
+ if (di->maps.len) {
+ rc = ddebug_attach_module_classes(dt, di, &reserved_ids);
+ if (rc) {
+ kfree(dt);
+ return rc;
+ }
+ }
mutex_lock(&ddebug_lock);
list_add_tail(&dt->link, &ddebug_tables);
mutex_unlock(&ddebug_lock);
- if (di->users.len)
- ddebug_attach_user_module_classes(dt, di);
+ if (di->users.len) {
+ rc = ddebug_attach_user_module_classes(dt, di, &reserved_ids);
+ if (rc)
+ return rc;
+ }
vpr_info("%3u debug prints in module %s\n", di->descs.len, modname);
return 0;
}
@@ -1400,6 +1413,11 @@ static int ddebug_module_notify(struct notifier_block *self, unsigned long val,
switch (val) {
case MODULE_STATE_COMING:
ret = ddebug_add_module(&mod->dyndbg_info, mod->name);
+ if (ret == -EINVAL) {
+ pr_err("conflicting dyndbg-classmap reservations\n");
+ ddebug_remove_module(mod->name);
+ break;
+ }
if (ret)
WARN(1, "Failed to allocate memory: dyndbg may not work properly.\n");
break;
--
Louis Chauvet, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com
