diff options
| author | Andy Lutomirski <luto@kernel.org> | 2016-09-30 20:58:58 +0300 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-10-20 10:21:41 +0300 |
| commit | d17af5056cf9e9fc05e68832f7c15687fcc12281 (patch) | |
| tree | 5849ec3001300e88b215f9d4e47e6b2b18e335fa /mm/util.c | |
| parent | b18cb64ead400c01bf1580eeba330ace51f8087d (diff) | |
| download | linux-d17af5056cf9e9fc05e68832f7c15687fcc12281.tar.xz | |
mm: Change vm_is_stack_for_task() to vm_is_stack_for_current()
Asking for a non-current task's stack can't be done without races
unless the task is frozen in kernel mode. As far as I know,
vm_is_stack_for_task() never had a safe non-current use case.
The __unused annotation is because some KSTK_ESP implementations
ignore their parameter, which IMO is further justification for this
patch.
Signed-off-by: Andy Lutomirski <luto@kernel.org>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Jann Horn <jann@thejh.net>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Linux API <linux-api@vger.kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tycho Andersen <tycho.andersen@canonical.com>
Link: http://lkml.kernel.org/r/4c3f68f426e6c061ca98b4fc7ef85ffbb0a25b0c.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'mm/util.c')
| -rw-r--r-- | mm/util.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/mm/util.c b/mm/util.c index 662cddf914af..c174e8921995 100644 --- a/mm/util.c +++ b/mm/util.c @@ -230,8 +230,10 @@ void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma, } /* Check if the vma is being used as a stack by this task */ -int vma_is_stack_for_task(struct vm_area_struct *vma, struct task_struct *t) +int vma_is_stack_for_current(struct vm_area_struct *vma) { + struct task_struct * __maybe_unused t = current; + return (vma->vm_start <= KSTK_ESP(t) && vma->vm_end >= KSTK_ESP(t)); } |