mm: don't skip arch_sync_kernel_mappings() in error paths

Fix callers that previously skipped calling arch_sync_kernel_mappings() if
an error occurred during a pgtable update.  The call is still required to
sync any pgtable updates that may have occurred prior to hitting the error
condition.

These are theoretical bugs discovered during code review.

Link: https://lkml.kernel.org/r/20250226121610.2401743-1-ryan.roberts@arm.com
Fixes: 2ba3e6947a ("mm/vmalloc: track which page-table levels were modified")
Fixes: 0c95cba492 ("mm: apply_to_pte_range warn and fail if a large pte is encountered")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christop Hellwig <hch@infradead.org>
Cc: "Uladzislau Rezki (Sony)" <urezki@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
pull/1172/head
Ryan Roberts 2025-02-26 12:16:09 +00:00 committed by Andrew Morton
parent adae46ac1e
commit 3685024edd
2 changed files with 6 additions and 4 deletions

View File

@ -3051,8 +3051,10 @@ static int __apply_to_page_range(struct mm_struct *mm, unsigned long addr,
next = pgd_addr_end(addr, end);
if (pgd_none(*pgd) && !create)
continue;
if (WARN_ON_ONCE(pgd_leaf(*pgd)))
return -EINVAL;
if (WARN_ON_ONCE(pgd_leaf(*pgd))) {
err = -EINVAL;
break;
}
if (!pgd_none(*pgd) && WARN_ON_ONCE(pgd_bad(*pgd))) {
if (!create)
continue;

View File

@ -586,13 +586,13 @@ static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
mask |= PGTBL_PGD_MODIFIED;
err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
if (err)
return err;
break;
} while (pgd++, addr = next, addr != end);
if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
arch_sync_kernel_mappings(start, end);
return 0;
return err;
}
/*