diff options
| author | Xiu Jianfeng <xiujianfeng@huawei.com> | 2023-09-06 10:33:12 +0000 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2023-10-04 10:32:21 -0700 |
| commit | 7fa38d0ea00ffe2cd3c95c96c85221b8ae221875 (patch) | |
| tree | c69cae9292de0ff50d7a918fb416cb2fb67a540d /mm/mmap.c | |
| parent | 2d00946bd7f4e8c17cbd2fce5fd7c3ab58046dff (diff) | |
mm: remove duplicated vma->vm_flags check when expanding stack
expand_upwards() and expand_downwards() will return -EFAULT if VM_GROWSUP
or VM_GROWSDOWN is not correctly set in vma->vm_flags, however in
!CONFIG_STACK_GROWSUP case, expand_stack_locked() returns -EINVAL first if
!(vma->vm_flags & VM_GROWSDOWN) before calling expand_downwards(), to keep
the consistency with CONFIG_STACK_GROWSUP case, remove this check.
The usages of this function are as below:
A:fs/exec.c
ret = expand_stack_locked(vma, stack_base);
if (ret)
ret = -EFAULT;
or
B:mm/memory.c mm/mmap.c
if (expand_stack_locked(vma, addr))
return NULL;
which means the return value will not propagate to other places, so I
believe there is no user-visible effects of this change, and it's
unnecessary to backport to earlier versions.
Link: https://lkml.kernel.org/r/20230906103312.645712-1-xiujianfeng@huaweicloud.com
Fixes: f440fa1ac955 ("mm: make find_extend_vma() fail if write lock not held")
Signed-off-by: Xiu Jianfeng <xiujianfeng@huawei.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 2 |
1 files changed, 0 insertions, 2 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index 1ec6c875a7f9..42870c4d8704 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -2159,8 +2159,6 @@ struct vm_area_struct *find_extend_vma_locked(struct mm_struct *mm, unsigned lon #else int expand_stack_locked(struct vm_area_struct *vma, unsigned long address) { - if (unlikely(!(vma->vm_flags & VM_GROWSDOWN))) - return -EINVAL; return expand_downwards(vma, address); } |