Revert "mm: Always release pages to the buddy allocator in memblock_free_late()."
PATCH 1/1 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 <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.
--- mm/memblock.c | 8 +------- tools/testing/memblock/internal.h | 4 ---- 2 files changed, 1 insertion(+), 11 deletions(-)
mm/memblock.c +1 -7
@@ -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 (); } }
tools/testing/memblock/internal.h +0 -4
@@ -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) {
Signature · 1 line
2.30.2
Quoted 22 lines · Aaron Thompson
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.
Quoted 6 lines
Fixes 115d9d77bb0f ("mm: Always release pages to the buddy allocator in memblock_free_late().")Signed-off-by Aaron Thompson <[email protected]>--- mm/memblock.c | 8 +------- tools/testing/memblock/internal.h | 4 ---- 2 files changed, 1 insertion(+), 11 deletions(-)
Applied, thanks!
Quoted 38 lines
mm/memblock.c +1
-7@@ -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 (); } }tools/testing/memblock/internal.h +0
-4@@ -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) {Signature · 1 line
2.30.2
Signature · 2 lines
Sincerely yours, Mike.