After shutdown_mem_profiling() clears mem_profiling_support,
needs_section_mem() returns false, so later modules have their codetag
section placed as regular data and never enter the alloc_tag maple tree.
codetag_load_module() still called load_module(), which allocated a percpu
counter for every tag; release_module_tags() could not find these modules
on unload, so the counters leaked.
Return CODETAG_MODULE_EXCLUDED from load_module() when profiling is off:
codetag_module_init() drops the module's cmod and no counters are
allocated. codetag_unload_module() now always calls free_section_mem(),
since an excluded module may still hold a reserved section.
Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compression")
Signed-off-by: Hao Ge <[email protected]>
---
include/linux/codetag.h | 4 ++++
lib/codetag.c | 8 +++++---
mm/alloc_tag.c | 8 ++++++--
3 files changed, 15 insertions(+), 5 deletions(-)
diff --git a/include/linux/codetag.h b/include/linux/codetag.h
index a25a085c2df1..88081c618673 100644
--- a/include/linux/codetag.h
+++ b/include/linux/codetag.h
@@ -52,6 +52,10 @@ struct codetag_type_desc {
#endif
};
+/* module_load() return values */
+#define CODETAG_MODULE_LOAD 0 /* module loads with its tags */
+#define CODETAG_MODULE_EXCLUDED 1 /* module loads without its
tags */
+
struct codetag_iterator {
struct codetag_type *cttype;
struct codetag_module *cmod;
diff --git a/lib/codetag.c b/lib/codetag.c
index a9cda4c962a3..8506ecab9ea7 100644
--- a/lib/codetag.c
+++ b/lib/codetag.c
@@ -238,9 +238,10 @@ static int codetag_module_init(struct codetag_type
*cttype, struct module *mod)
}
up_write(&cttype->mod_lock);
- if (err < 0) {
+ if (err) {
+ /* Error or excluded: cmod is dropped, free it. */
kfree(cmod);
- return err;
+ return err < 0 ? err : 0;
}
return 0;
@@ -388,7 +389,8 @@ void codetag_unload_module(struct module *mod)
++cttype->content_id;
}
up_write(&cttype->mod_lock);
- if (found && cttype->desc.free_section_mem)
+ /* an excluded module may still hold section memory */
+ if (cttype->desc.free_section_mem)
cttype->desc.free_section_mem(mod, true);
}
mutex_unlock(&codetag_lock);
diff --git a/mm/alloc_tag.c b/mm/alloc_tag.c
index 0a7b657fe2de..461fa87fbb0b 100644
--- a/mm/alloc_tag.c
+++ b/mm/alloc_tag.c
@@ -977,9 +977,13 @@ static int load_module(struct module *mod, struct codetag
*start, struct codetag
struct alloc_tag *stop_tag;
struct alloc_tag *tag;
+ /* Profiling disabled: load the module but exclude its tags. */
+ if (!mem_profiling_support)
+ return CODETAG_MODULE_EXCLUDED;
+
/* percpu counters for core allocations are already statically
allocated */
if (!mod)
- return 0;
+ return CODETAG_MODULE_LOAD;
start_tag = ct_to_alloc_tag(start);
stop_tag = ct_to_alloc_tag(stop);
@@ -1002,7 +1006,7 @@ static int load_module(struct module *mod, struct codetag
*start, struct codetag
*/
kmemleak_ignore_percpu(tag->counters);
}
- return 0;
+ return CODETAG_MODULE_LOAD;
}
static void replace_module(struct module *mod, struct module *new_mod)
--
2.25.1
