diff options
author | Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> | 2007-03-10 03:19:49 -0500 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2007-03-10 03:19:49 -0500 |
commit | c0a79b229ac0e3a96fc00d5be65a498ceb06ef63 (patch) | |
tree | 5eda8f742f1480abf16952d6ba820be6a95d29b4 /arch/sparc64/kernel/process.c | |
parent | 63abdcdc021063bf1cfcddfd3c1a14a761539807 (diff) |
[SPARC64]: Fix atomicity of TIF update in flush_thread()
Fix atomicity of TIF update in flush_thread() for sparc64
Fixes correctly the race by using *_ti_thread_flag.
Race :
parent process executing :
sys_ptrace()
(lock_kernel())
(ptrace_get_task_struct(pid))
arch_ptrace()
ptrace_detach()
ptrace_disable(child);
clear_singlestep(child);
clear_tsk_thread_flag(child, TIF_SINGLESTEP);
(which clears the TIF_SINGLESTEP flag atomically from a different
process)
(put_task_struct(child))
(unlock_kernel())
And at the same time, in the child process :
sys_execve()
do_execve()
search_binary_handler()
load_elf_binary()
flush_old_exec()
flush_thread()
doing a non-atomic thread flag update
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'arch/sparc64/kernel/process.c')
-rw-r--r-- | arch/sparc64/kernel/process.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/arch/sparc64/kernel/process.c b/arch/sparc64/kernel/process.c index 7d75cd4eb297..b291060c25a6 100644 --- a/arch/sparc64/kernel/process.c +++ b/arch/sparc64/kernel/process.c | |||
@@ -413,8 +413,13 @@ void flush_thread(void) | |||
413 | struct thread_info *t = current_thread_info(); | 413 | struct thread_info *t = current_thread_info(); |
414 | struct mm_struct *mm; | 414 | struct mm_struct *mm; |
415 | 415 | ||
416 | if (t->flags & _TIF_ABI_PENDING) | 416 | if (test_ti_thread_flag(t, TIF_ABI_PENDING)) { |
417 | t->flags ^= (_TIF_ABI_PENDING | _TIF_32BIT); | 417 | clear_ti_thread_flag(t, TIF_ABI_PENDING); |
418 | if (test_ti_thread_flag(t, TIF_32BIT)) | ||
419 | clear_ti_thread_flag(t, TIF_32BIT); | ||
420 | else | ||
421 | set_ti_thread_flag(t, TIF_32BIT); | ||
422 | } | ||
418 | 423 | ||
419 | mm = t->task->mm; | 424 | mm = t->task->mm; |
420 | if (mm) | 425 | if (mm) |