If a module _DEFINEs + _USEs 2 or more classmaps, it must devise them
to share the per-module 0..62 class-id space; ie their respective
base,+length reservations cannot overlap.
To detect conflicts at modprobe, add ddebug_class_range_overlap(),
call it from ddebug_add_module(), and WARN and return -EINVAL when
they're detected.
test_dynamic_debug.c:
If built with -DFORCE_CLASSID_CONFLICT, the test-modules get 2 bad
DYNDBG_CLASS_DEFINE declarations, into parent and the _submod. These
conflict with one of the good ones in the parent (D2_CORE..etc),
causing the modprobe(s) to warn
Signed-off-by: Jim Cromie <jim.cro...@gmail.com>
---
---
lib/dynamic_debug.c | 29 +++++++++++++++++++++++++++++
lib/test_dynamic_debug.c | 8 ++++++++
2 files changed, 37 insertions(+)
diff --git a/lib/dynamic_debug.c b/lib/dynamic_debug.c
index 53e261dbf81e..56b503af0b31 100644
--- a/lib/dynamic_debug.c
+++ b/lib/dynamic_debug.c
@@ -1267,6 +1267,22 @@ static void ddebug_apply_class_users(const struct
_ddebug_info *di)
(_dst)->info._vec.len = nc; \
})
+static int __maybe_unused
+ddebug_class_range_overlap(struct _ddebug_class_map *cm,
+ u64 *reserved_ids)
+{
+ u64 range = (((1ULL << cm->length) - 1) << cm->base);
+
+ if (range & *reserved_ids) {
+ pr_err("[%d..%d] on %s conflicts with %llx\n", cm->base,
+ cm->base + cm->length - 1, cm->class_names[0],
+ *reserved_ids);
+ return -EINVAL;
+ }
+ *reserved_ids |= range;
+ return 0;
+}
+
/*
* Allocate a new ddebug_table for the given module
* and add it to the global list.
@@ -1276,6 +1292,7 @@ static int ddebug_add_module(struct _ddebug_info *di)
struct ddebug_table *dt;
struct _ddebug_class_map *cm;
struct _ddebug_class_user *cli;
+ u64 reserved_ids = 0;
int i;
if (!di->descs.len)
@@ -1301,6 +1318,13 @@ static int ddebug_add_module(struct _ddebug_info *di)
dd_mark_vector_subrange(i, dt, cm, di, maps);
dd_mark_vector_subrange(i, dt, cli, di, users);
+ for_subvec(i, cm, &dt->info, maps)
+ if (ddebug_class_range_overlap(cm, &reserved_ids))
+ goto cleanup;
+ for_subvec(i, cli, &dt->info, users)
+ if (ddebug_class_range_overlap(cli->map, &reserved_ids))
+ goto cleanup;
+
if (dt->info.maps.len)
ddebug_apply_class_maps(&dt->info);
@@ -1313,6 +1337,11 @@ static int ddebug_add_module(struct _ddebug_info *di)
vpr_info("%3u debug prints in module %s\n", di->descs.len,
di->mod_name);
return 0;
+cleanup:
+ WARN_ONCE("dyndbg multi-classmap conflict in %s\n", di->mod_name);
+ kfree(dt);
+ return -EINVAL;
+
}
/* helper for ddebug_dyndbg_(boot|module)_param_cb */
diff --git a/lib/test_dynamic_debug.c b/lib/test_dynamic_debug.c
index 1070107f74f1..e42916b08fd4 100644
--- a/lib/test_dynamic_debug.c
+++ b/lib/test_dynamic_debug.c
@@ -128,6 +128,14 @@ DYNAMIC_DEBUG_CLASSMAP_DEFINE(map_level_num,
DD_CLASS_TYPE_LEVEL_NUM,
DYNAMIC_DEBUG_CLASSMAP_PARAM(disjoint_bits, p);
DYNAMIC_DEBUG_CLASSMAP_PARAM(level_num, p);
+#ifdef FORCE_CLASSID_CONFLICT
+/*
+ * Enable with -Dflag on compile to test overlapping class-id range
+ * detection. This should warn on modprobes.
+ */
+DYNDBG_CLASSMAP_DEFINE(classid_range_conflict, 0, D2_CORE + 1, "D3_CORE");
+#endif
+
#else /* TEST_DYNAMIC_DEBUG_SUBMOD */
/*
--
2.49.0
