Re: [PATCH 01/23] arm: allow pte_offset_map[_lock]() to fail
From: Matthew Wilcox <willy@infradead.org>
Date: 2023-05-10 14:29:17
Also in:
linux-m68k, linux-mips, linux-mm, linux-riscv, linux-s390, linux-sh, lkml, sparclinux
On Tue, May 09, 2023 at 09:42:44PM -0700, Hugh Dickins wrote:
quoted hunk ↗ jump to hunk
diff --git a/arch/arm/lib/uaccess_with_memcpy.c b/arch/arm/lib/uaccess_with_memcpy.c index e4c2677cc1e9..2f6163f05e93 100644 --- a/arch/arm/lib/uaccess_with_memcpy.c +++ b/arch/arm/lib/uaccess_with_memcpy.c@@ -74,6 +74,9 @@ pin_page_for_write(const void __user *_addr, pte_t **ptep, spinlock_t **ptlp) return 0; pte = pte_offset_map_lock(current->mm, pmd, addr, &ptl); + if (unlikely(!pte)) + return 0;
Failing seems like the wrong thig to do if we transitioned from a PTE to PMD here? Looks to me like we should goto a new label right after the 'pmd = pmd_offset(pud, addr);', no?