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| author | Yong Zhang <yong.zhang@windriver.com> | 2012-05-15 13:53:56 +0800 |
|---|---|---|
| committer | Steven Rostedt <rostedt@rostedt.homelinux.com> | 2013-12-06 20:55:51 -0500 |
| commit | a4e89a3786cd52f5f22682bafc4e8ccbb737f5c8 (patch) | |
| tree | 6c003ab15fd7cd10d2a03e31ef85aca05c8c52f3 /fs | |
| parent | 2171393bc02a63bfe8f81d0ecfa7c47d1112ab2c (diff) | |
| download | linux-rt-a4e89a3786cd52f5f22682bafc4e8ccbb737f5c8.tar.gz | |
mm: Protect activate_mm() by preempt_[disable%7Cenable]_rt()
Otherwise there will be warning on ARM like below:
WARNING: at build/linux/kernel/smp.c:459 smp_call_function_many+0x98/0x264()
Modules linked in:
[<c0013bb4>] (unwind_backtrace+0x0/0xe4) from [<c001be94>] (warn_slowpath_common+0x4c/0x64)
[<c001be94>] (warn_slowpath_common+0x4c/0x64) from [<c001bec4>] (warn_slowpath_null+0x18/0x1c)
[<c001bec4>] (warn_slowpath_null+0x18/0x1c) from [<c0053ff8>](smp_call_function_many+0x98/0x264)
[<c0053ff8>] (smp_call_function_many+0x98/0x264) from [<c0054364>] (smp_call_function+0x44/0x6c)
[<c0054364>] (smp_call_function+0x44/0x6c) from [<c0017d50>] (__new_context+0xbc/0x124)
[<c0017d50>] (__new_context+0xbc/0x124) from [<c009e49c>] (flush_old_exec+0x460/0x5e4)
[<c009e49c>] (flush_old_exec+0x460/0x5e4) from [<c00d61ac>] (load_elf_binary+0x2e0/0x11ac)
[<c00d61ac>] (load_elf_binary+0x2e0/0x11ac) from [<c009d060>] (search_binary_handler+0x94/0x2a4)
[<c009d060>] (search_binary_handler+0x94/0x2a4) from [<c009e8fc>] (do_execve+0x254/0x364)
[<c009e8fc>] (do_execve+0x254/0x364) from [<c0010e84>] (sys_execve+0x34/0x54)
[<c0010e84>] (sys_execve+0x34/0x54) from [<c000da00>] (ret_fast_syscall+0x0/0x30)
---[ end trace 0000000000000002 ]---
The reason is that ARM need irq enabled when doing activate_mm().
According to mm-protect-activate-switch-mm.patch, actually
preempt_[disable|enable]_rt() is sufficient.
Inspired-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Yong Zhang <yong.zhang0@gmail.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/1337061236-1766-1-git-send-email-yong.zhang0@gmail.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/exec.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/fs/exec.c b/fs/exec.c index 453f2098bc0f..1c2119291549 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -840,12 +840,12 @@ static int exec_mmap(struct mm_struct *mm) } } task_lock(tsk); - local_irq_disable_rt(); + preempt_disable_rt(); active_mm = tsk->active_mm; tsk->mm = mm; tsk->active_mm = mm; activate_mm(active_mm, mm); - local_irq_enable_rt(); + preempt_enable_rt(); task_unlock(tsk); arch_pick_mmap_layout(mm); if (old_mm) { |