From: Uladzislau Rezki (Sony) Date: Tue, 7 Oct 2025 12:20:31 +0000 (+0200) Subject: mm/kasan: support non-blocking GFP in kasan_populate_vmalloc() X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=eee2352830226fa4fc8dda46a16bdc5a546ecd01;p=users%2Fjedix%2Flinux-maple.git mm/kasan: support non-blocking GFP in kasan_populate_vmalloc() A "gfp_mask" is already passed to kasan_populate_vmalloc() as an argument to respect GFPs from callers and KASAN uses it for its internal allocations. But apply_to_page_range() function ignores GFP flags due to a hard-coded mask. Wrap the call with memalloc_apply_gfp_scope()/memalloc_restore_scope() so that non-blocking GFP flags(GFP_ATOMIC, GFP_NOWAIT) are respected. Link: https://lkml.kernel.org/r/20251007122035.56347-7-urezki@gmail.com Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Baoquan He Reviewed-by: Andrey Ryabinin Cc: Alexander Potapenko Cc: Marco Elver Cc: Michal Hocko Cc: Michal Hocko Signed-off-by: Andrew Morton --- diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 5d2a876035d6..a30d84bfdd52 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -377,18 +377,10 @@ static int __kasan_populate_vmalloc(unsigned long start, unsigned long end, gfp_ * page tables allocations ignore external gfp mask, enforce it * by the scope API */ - if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) - flags = memalloc_nofs_save(); - else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) - flags = memalloc_noio_save(); - + flags = memalloc_apply_gfp_scope(gfp_mask); ret = apply_to_page_range(&init_mm, start, nr_pages * PAGE_SIZE, kasan_populate_vmalloc_pte, &data); - - if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) - memalloc_nofs_restore(flags); - else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) - memalloc_noio_restore(flags); + memalloc_restore_scope(flags); ___free_pages_bulk(data.pages, nr_pages); if (ret)