diff options
Diffstat (limited to 'arch/sh/kernel/unwinder.c')
| -rw-r--r-- | arch/sh/kernel/unwinder.c | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/arch/sh/kernel/unwinder.c b/arch/sh/kernel/unwinder.c index 2b30fa28b44..468889d958f 100644 --- a/arch/sh/kernel/unwinder.c +++ b/arch/sh/kernel/unwinder.c @@ -11,6 +11,7 @@ #include <linux/errno.h> #include <linux/list.h> #include <linux/spinlock.h> +#include <linux/module.h> #include <asm/unwinder.h> #include <asm/atomic.h> @@ -53,8 +54,6 @@ static struct list_head unwinder_list = { static DEFINE_SPINLOCK(unwinder_lock); -static atomic_t unwinder_running = ATOMIC_INIT(0); - /** * select_unwinder - Select the best registered stack unwinder. * @@ -122,6 +121,8 @@ int unwinder_register(struct unwinder *u) return ret; } +int unwinder_faulted = 0; + /* * Unwind the call stack and pass information to the stacktrace_ops * functions. Also handle the case where we need to switch to a new @@ -144,19 +145,20 @@ void unwind_stack(struct task_struct *task, struct pt_regs *regs, * Hopefully this will give us a semi-reliable stacktrace so we * can diagnose why curr_unwinder->dump() faulted. */ - if (atomic_inc_return(&unwinder_running) != 1) { + if (unwinder_faulted) { spin_lock_irqsave(&unwinder_lock, flags); - if (!list_is_singular(&unwinder_list)) { + /* Make sure no one beat us to changing the unwinder */ + if (unwinder_faulted && !list_is_singular(&unwinder_list)) { list_del(&curr_unwinder->list); curr_unwinder = select_unwinder(); + + unwinder_faulted = 0; } spin_unlock_irqrestore(&unwinder_lock, flags); - atomic_dec(&unwinder_running); } curr_unwinder->dump(task, regs, sp, ops, data); - - atomic_dec(&unwinder_running); } +EXPORT_SYMBOL_GPL(unwind_stack); |