From 647037adcad00f2bab8828d3d41cd0553d41f3bd Mon Sep 17 00:00:00 2001 From: Aaron Thompson Date: Tue, 7 Feb 2023 08:21:51 +0000 Subject: [PATCH] Revert "mm: Always release pages to the buddy allocator in memblock_free_late()." This reverts commit 115d9d77bb0f9152c60b6e8646369fa7f6167593. The pages being freed by memblock_free_late() have already been initialized, but if they are in the deferred init range, __free_one_page() might access nearby uninitialized pages when trying to coalesce buddies. This can, for example, trigger this BUG: BUG: unable to handle page fault for address: ffffe964c02580c8 RIP: 0010:__list_del_entry_valid+0x3f/0x70 __free_one_page+0x139/0x410 __free_pages_ok+0x21d/0x450 memblock_free_late+0x8c/0xb9 efi_free_boot_services+0x16b/0x25c efi_enter_virtual_mode+0x403/0x446 start_kernel+0x678/0x714 secondary_startup_64_no_verify+0xd2/0xdb A proper fix will be more involved so revert this change for the time being. Fixes: 115d9d77bb0f ("mm: Always release pages to the buddy allocator in memblock_free_late().") Signed-off-by: Aaron Thompson Link: https://lore.kernel.org/r/20230207082151.1303-1-dev@aaront.org Signed-off-by: Mike Rapoport (IBM) --- mm/memblock.c | 8 +------- tools/testing/memblock/internal.h | 4 ---- 2 files changed, 1 insertion(+), 11 deletions(-) diff --git a/mm/memblock.c b/mm/memblock.c index 685e30e6d27c..d036c7861310 100644 --- a/mm/memblock.c +++ b/mm/memblock.c @@ -1640,13 +1640,7 @@ void __init memblock_free_late(phys_addr_t base, phys_addr_t size) end = PFN_DOWN(base + size); for (; cursor < end; cursor++) { - /* - * Reserved pages are always initialized by the end of - * memblock_free_all() (by memmap_init() and, if deferred - * initialization is enabled, memmap_init_reserved_pages()), so - * these pages can be released directly to the buddy allocator. - */ - __free_pages_core(pfn_to_page(cursor), 0); + memblock_free_pages(pfn_to_page(cursor), cursor, 0); totalram_pages_inc(); } } diff --git a/tools/testing/memblock/internal.h b/tools/testing/memblock/internal.h index 85973e55489e..fdb7f5db7308 100644 --- a/tools/testing/memblock/internal.h +++ b/tools/testing/memblock/internal.h @@ -15,10 +15,6 @@ bool mirrored_kernelcore = false; struct page {}; -void __free_pages_core(struct page *page, unsigned int order) -{ -} - void memblock_free_pages(struct page *page, unsigned long pfn, unsigned int order) {