From: Aaron Thompson dev@aaront.org
commit 647037adcad00f2bab8828d3d41cd0553d41f3bd upstream.
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 <TASK> __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 </TASK>
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 dev@aaront.org Link: https://lore.kernel.org/r/20230207082151.1303-1-dev@aaront.org Signed-off-by: Mike Rapoport (IBM) rppt@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/memblock.c | 8 +------- tools/testing/memblock/internal.h | 4 ---- 2 files changed, 1 insertion(+), 11 deletions(-)
--- a/mm/memblock.c +++ b/mm/memblock.c @@ -1640,13 +1640,7 @@ void __init memblock_free_late(phys_addr 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(); } } --- 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) {