On 07.04.24 15:05, Oscar Salvador wrote:
Tony reported that the Machine check recovery was broken in v6.9-rc1,
as he was hitting a VM_BUG_ON when injecting uncorrectable memory errors
to DRAM.
After some more digging and debugging on his side, he realized that this
went back to v6.1, with the introduction of 'commit 0d206b5d2e0d ("mm/swap: add
swp_offset_pfn() to fetch PFN from swap entry")'.
That commit, among other things, introduced swp_offset_pfn(), replacing
hwpoison_entry_to_pfn() in its favour.
The patch also introduced a VM_BUG_ON() check for is_pfn_swap_entry(),
but is_pfn_swap_entry() never got updated to cover hwpoison entries, which
means that we would hit the VM_BUG_ON whenever we would call
swp_offset_pfn() for such entries on environments with CONFIG_DEBUG_VM set.
Fix this by updating the check to cover hwpoison entries as well, and update
the comment while we are it.
Reported-by: Tony Luck <tony.luck@xxxxxxxxx>
Closes: https://lore.kernel.org/all/Zg8kLSl2yAlA3o5D@agluck-desk3/
Tested-by: Tony Luck <tony.luck@xxxxxxxxx>
Fixes: 0d206b5d2e0d ("mm/swap: add swp_offset_pfn() to fetch PFN from swap entry")
Cc: <stable@xxxxxxxxxxxxxxx> # 6.1.x
Signed-off-by: Oscar Salvador <osalvador@xxxxxxx>
---
Reviewed-by: David Hildenbrand <david@xxxxxxxxxx>
--
Cheers,
David / dhildenb
