Maksytka/linux
1
1
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2025-11-30 23:16:01 +07:00
Code Issues Packages Projects Releases Wiki Activity

kho: warn and exit when unpreserved page wasn't preserved

Browse Source 
Calling __kho_unpreserve() on a pair of (pfn, end_pfn) that wasn't
preserved is a bug.  Currently, if that is done, the physxa or bits can be
NULL.  This results in a soft lockup since a NULL physxa or bits results
in redoing the loop without ever making any progress.

Return when physxa or bits are not found, but WARN first to loudly
indicate invalid behaviour.

Link: https://lkml.kernel.org/r/20251103180235.71409-3-pratyush@kernel.org
Fixes: fc33e4b44b ("kexec: enable KHO support for memory preservation")
Signed-off-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
This commit is contained in:
Pratyush Yadav
2025-11-03 19:02:32 +01:00
committed by Andrew Morton
parent 7ecd2e439d
commit b05addf6f0
1 changed files with 4 additions and 4 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
kernel/kexec_handover.c
View File

@@ -171,12 +171,12 @@ static void __kho_unpreserve(struct kho_mem_track *track, unsigned long pfn,
const unsigned long pfn_high = pfn >> order;
physxa = xa_load(&track->orders, order);
if (!physxa)
continue;
if (WARN_ON_ONCE(!physxa))
return;
bits = xa_load(&physxa->phys_bits, pfn_high / PRESERVE_BITS);
if (!bits)
continue;
if (WARN_ON_ONCE(!bits))
return;
clear_bit(pfn_high % PRESERVE_BITS, bits->preserve);