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 -EOPNOTSUPP from load_module() when profiling is off: codetag_module_init() drops the module's cmod, no counters are allocated and the module loads without its tags. codetag_unload_module() now always calls free_section_mem(), since a module whose module_load() returned -EOPNOTSUPP is not in the idr but may still hold a reserved section. Reported-by: Sashiko <[email protected]> Fixes: 4835f747d3ed ("alloc_tag: support for page allocation tag compression") Cc: [email protected] Suggested-by: Suren Baghdasaryan <[email protected]> Acked-by: Suren Baghdasaryan <[email protected]> Signed-off-by: Hao Ge <[email protected]> --- lib/codetag.c | 10 ++++++++-- mm/alloc_tag.c | 4 ++++ 2 files changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/codetag.c b/lib/codetag.c index a9cda4c962a3..a0b600720afc 100644 --- a/lib/codetag.c +++ b/lib/codetag.c @@ -240,7 +240,9 @@ static int codetag_module_init(struct codetag_type *cttype, struct module *mod) if (err < 0) { kfree(cmod); - return err; + /* -EOPNOTSUPP means we can load the module without its tag. */ + if (err != -EOPNOTSUPP) + return err; } return 0; @@ -388,7 +390,11 @@ void codetag_unload_module(struct module *mod) ++cttype->content_id; } up_write(&cttype->mod_lock); - if (found && cttype->desc.free_section_mem) + /* + * A module whose module_load() returned -EOPNOTSUPP is not + * in the idr but may still hold reserved 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 5836803898ad..1ca0409b492b 100644 --- a/mm/alloc_tag.c +++ b/mm/alloc_tag.c @@ -988,6 +988,10 @@ 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 without its tags. */ + if (!mem_profiling_support) + return -EOPNOTSUPP; + /* percpu counters for core allocations are already statically allocated */ if (!mod) return 0; -- 2.25.1
