Commit bea493a0 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Linus Torvalds

[PATCH] rt-mutex: fixup rt-mutex debug code

BUG: warning at kernel/rtmutex-debug.c:125/rt_mutex_debug_task_free() (Not tainted)
 [<c04051e3>] show_trace_log_lvl+0x58/0x16a
 [<c04057f0>] show_trace+0xd/0x10
 [<c0405900>] dump_stack+0x19/0x1b
 [<c043f03d>] rt_mutex_debug_task_free+0x35/0x6a
 [<c04224c0>] free_task+0x15/0x24
 [<c042378c>] copy_process+0x12bd/0x1324
 [<c0423835>] do_fork+0x42/0x113
 [<c04021dd>] sys_fork+0x19/0x1b
 [<c0403fb7>] syscall_call+0x7/0xb

In copy_process(), dup_task_struct() also duplicates the ->pi_lock,
->pi_waiters and ->pi_blocked_on members.  rt_mutex_debug_task_free()
called from free_task() validates these members.  However free_task() can
be invoked before these members are reset for the new task.

Move the initialization code before the first bail that can hit free_task().
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
Acked-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@osdl.org>
parent 91b943ee
...@@ -984,6 +984,8 @@ static struct task_struct *copy_process(unsigned long clone_flags, ...@@ -984,6 +984,8 @@ static struct task_struct *copy_process(unsigned long clone_flags,
if (!p) if (!p)
goto fork_out; goto fork_out;
rt_mutex_init_task(p);
#ifdef CONFIG_TRACE_IRQFLAGS #ifdef CONFIG_TRACE_IRQFLAGS
DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->hardirqs_enabled);
DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled); DEBUG_LOCKS_WARN_ON(!p->softirqs_enabled);
...@@ -1088,8 +1090,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, ...@@ -1088,8 +1090,6 @@ static struct task_struct *copy_process(unsigned long clone_flags,
p->lockdep_recursion = 0; p->lockdep_recursion = 0;
#endif #endif
rt_mutex_init_task(p);
#ifdef CONFIG_DEBUG_MUTEXES #ifdef CONFIG_DEBUG_MUTEXES
p->blocked_on = NULL; /* not blocked yet */ p->blocked_on = NULL; /* not blocked yet */
#endif #endif
......
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