diff options
| author | David Hildenbrand <david@redhat.com> | 2025-04-08 10:59:50 +0200 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-04-11 17:32:41 -0700 |
| commit | 8c56c5dbcf52220cc9be7a36e7f21ebd5939e0b9 (patch) | |
| tree | 1ae5ef4d77251090221b07f28c7c16098ceb0a52 /mm | |
| parent | 8ab1b16023961dc640023b10436d282f905835ad (diff) | |
mm: (un)track_pfn_copy() fix + doc improvements
We got a late smatch warning and some additional review feedback.
smatch warnings:
mm/memory.c:1428 copy_page_range() error: uninitialized symbol 'pfn'.
We actually use the pfn only when it is properly initialized; however, we
may pass an uninitialized value to a function -- although it will not use
it that likely still is UB in C.
So let's just fix it by always initializing pfn in the caller of
track_pfn_copy(), and improving the documentation of track_pfn_copy().
While at it, clarify the doc of untrack_pfn_copy(), that internal checks
make sure if we actually have to untrack anything.
Link: https://lkml.kernel.org/r/20250408085950.976103-1-david@redhat.com
Fixes: dc84bc2aba85 ("x86/mm/pat: Fix VM_PAT handling when fork() fails in copy_page_range()")
Signed-off-by: David Hildenbrand <david@redhat.com>
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/r/202503270941.IFILyNCX-lkp@intel.com/
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Rik van Riel <riel@surriel.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/memory.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/memory.c b/mm/memory.c index 2d8c265fc7d6..1a35165622e1 100644 --- a/mm/memory.c +++ b/mm/memory.c @@ -1361,7 +1361,7 @@ copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma) struct mm_struct *dst_mm = dst_vma->vm_mm; struct mm_struct *src_mm = src_vma->vm_mm; struct mmu_notifier_range range; - unsigned long next, pfn; + unsigned long next, pfn = 0; bool is_cow; int ret; |