Kernel can crash on failed VM_BUG_ON assertion in function move_freepages() on some rare physical memory mappings (with huge range(s) of memory reserved by BIOS followed by usable memory not aligned to pageblock).
crash> page_init_bug -v | grep resource | sed '/RAM .3/,/RAM .4/!d' <struct resource 0xffff88067fffd480> 4bfac000 - 646b1fff System RAM (391.02 MiB = 400408.00 KiB) <struct resource 0xffff88067fffd4b8> 646b2000 - 793fefff reserved (333.30 MiB = 341300.00 KiB) <struct resource 0xffff88067fffd4f0> 793ff000 - 7b3fefff ACPI Non-volatile Storage ( 32.00 MiB) <struct resource 0xffff88067fffd528> 7b3ff000 - 7b787fff ACPI Tables ( 3.54 MiB = 3620.00 KiB) <struct resource 0xffff88067fffd560> 7b788000 - 7b7fffff System RAM (480.00 KiB)
More details in second patch.
v2: Use -1 constant for max_pfn and remove the parameter. That's mostly just a cosmetics. v3: Split to two patches series to make clear what is the actual fix and what is just a clean up. No code changes compared to v2 and second patch is identical to original v1.
Cc: stable@vger.kernel.org
Daniel Vacek (2): mm/memblock: hardcode the max_pfn being -1 mm/page_alloc: fix memmap_init_zone pageblock alignment
mm/memblock.c | 13 ++++++------- mm/page_alloc.c | 9 +++++++-- 2 files changed, 13 insertions(+), 9 deletions(-)