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alloc_tag: introduce clear_page_tag_ref() helper function

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In several cases we are freeing pages which were not allocated using
common page allocators.  For such cases, in order to keep allocation
accounting correct, we should clear the page tag to indicate that the page
being freed is expected to not have a valid allocation tag.  Introduce
clear_page_tag_ref() helper function to be used for this.

Link: https://lkml.kernel.org/r/20240813150758.855881-1-surenb@google.com
Fixes: d224eb0287 ("codetag: debug: mark codetags for reserved pages as empty")
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>	[6.10]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Suren Baghdasaryan 2024-08-13 08:07:56 -07:00 committed by Andrew Morton
parent edb907a613
commit a8fc28dad6
3 changed files with 15 additions and 17 deletions
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13
include/linux/pgalloc_tag.h
View File

@ -43,6 +43,18 @@ static inline void put_page_tag_ref(union codetag_ref *ref)
page_ext_put(page_ext_from_codetag_ref(ref));
}
static inline void clear_page_tag_ref(struct page *page)
{
if (mem_alloc_profiling_enabled()) {
union codetag_ref *ref = get_page_tag_ref(page);
if (ref) {
set_codetag_empty(ref);
put_page_tag_ref(ref);
}
}
}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr)
{
@ -126,6 +138,7 @@ static inline void pgalloc_tag_sub_pages(struct alloc_tag *tag, unsigned int nr)
static inline union codetag_ref *get_page_tag_ref(struct page *page) { return NULL; }
static inline void put_page_tag_ref(union codetag_ref *ref) {}
static inline void clear_page_tag_ref(struct page *page) {}
static inline void pgalloc_tag_add(struct page *page, struct task_struct *task,
unsigned int nr) {}
static inline void pgalloc_tag_sub(struct page *page, unsigned int nr) {}

10
mm/mm_init.c
View File

@ -2459,15 +2459,7 @@ void __init memblock_free_pages(struct page *page, unsigned long pfn,
}
/* pages were reserved and not allocated */
if (mem_alloc_profiling_enabled()) {
union codetag_ref *ref = get_page_tag_ref(page);
if (ref) {
set_codetag_empty(ref);
put_page_tag_ref(ref);
}
}
clear_page_tag_ref(page);
__free_pages_core(page, order, MEMINIT_EARLY);
}

9
mm/page_alloc.c
View File

@ -5815,14 +5815,7 @@ unsigned long free_reserved_area(void *start, void *end, int poison, const char
void free_reserved_page(struct page *page)
{
if (mem_alloc_profiling_enabled()) {
union codetag_ref *ref = get_page_tag_ref(page);
if (ref) {
set_codetag_empty(ref);
put_page_tag_ref(ref);
}
}
clear_page_tag_ref(page);
ClearPageReserved(page);
init_page_count(page);
__free_page(page);