diff options
author | Andy Lutomirski <luto@kernel.org> | 2016-09-30 10:58:57 -0700 |
---|---|---|
committer | Ingo Molnar <mingo@kernel.org> | 2016-10-20 09:21:41 +0200 |
commit | b18cb64ead400c01bf1580eeba330ace51f8087d (patch) | |
tree | 2debc729e803790223c723bb4a4883f14135147f /include | |
parent | 0a1eb2d474edfe75466be6b4677ad84e5e8ca3f5 (diff) |
fs/proc: Stop trying to report thread stacks
This reverts more of:
b76437579d13 ("procfs: mark thread stack correctly in proc/<pid>/maps")
... which was partially reverted by:
65376df58217 ("proc: revert /proc/<pid>/maps [stack:TID] annotation")
Originally, /proc/PID/task/TID/maps was the same as /proc/TID/maps.
In current kernels, /proc/PID/maps (or /proc/TID/maps even for
threads) shows "[stack]" for VMAs in the mm's stack address range.
In contrast, /proc/PID/task/TID/maps uses KSTK_ESP to guess the
target thread's stack's VMA. This is racy, probably returns garbage
and, on arches with CONFIG_TASK_INFO_IN_THREAD=y, is also crash-prone:
KSTK_ESP is not safe to use on tasks that aren't known to be running
ordinary process-context kernel code.
This patch removes the difference and just shows "[stack]" for VMAs
in the mm's stack range. This is IMO much more sensible -- the
actual "stack" address really is treated specially by the VM code,
and the current thread stack isn't even well-defined for programs
that frequently switch stacks on their own.
Reported-by: Jann Horn <jann@thejh.net>
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: Johannes Weiner <hannes@cmpxchg.org>
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/3e678474ec14e0a0ec34c611016753eea2e1b8ba.1475257877.git.luto@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
0 files changed, 0 insertions, 0 deletions