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| author | Liam R. Howlett <Liam.Howlett@oracle.com> | 2023-06-16 15:58:54 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-06-24 14:13:54 -0700 |
| commit | f440fa1ac955e2898893f9301568435eb5cdfc4b (patch) | |
| tree | 5acff3435c93fdcb5527124ae4aadfcbd46ab866 /fs/exec.c | |
| parent | 2cd76c50d0b41cec5c87abfcdf25b236a2793fb6 (diff) | |
| download | lwn-f440fa1ac955e2898893f9301568435eb5cdfc4b.tar.gz lwn-f440fa1ac955e2898893f9301568435eb5cdfc4b.zip | |
mm: make find_extend_vma() fail if write lock not held
Make calls to extend_vma() and find_extend_vma() fail if the write lock
is required.
To avoid making this a flag-day event, this still allows the old
read-locking case for the trivial situations, and passes in a flag to
say "is it write-locked". That way write-lockers can say "yes, I'm
being careful", and legacy users will continue to work in all the common
cases until they have been fully converted to the new world order.
Co-Developed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/exec.c')
| -rw-r--r-- | fs/exec.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/exec.c b/fs/exec.c index a466e797c8e2..a61eb256e5e4 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -205,7 +205,8 @@ static struct page *get_arg_page(struct linux_binprm *bprm, unsigned long pos, #ifdef CONFIG_STACK_GROWSUP if (write) { - ret = expand_downwards(bprm->vma, pos); + /* We claim to hold the lock - nobody to race with */ + ret = expand_downwards(bprm->vma, pos, true); if (ret < 0) return NULL; } @@ -853,7 +854,7 @@ int setup_arg_pages(struct linux_binprm *bprm, stack_base = vma->vm_end - stack_expand; #endif current->mm->start_stack = bprm->p; - ret = expand_stack(vma, stack_base); + ret = expand_stack_locked(vma, stack_base, true); if (ret) ret = -EFAULT; |