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@xxxxxxxxxx>
---
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)
{
--
2.30.2
