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authorPaul Mundt <lethal@linux-sh.org>2009-09-01 13:54:14 +0900
committerPaul Mundt <lethal@linux-sh.org>2009-09-01 13:54:14 +0900
commitac6a0cf6716bb46813d0161024c66c2af66e53d1 (patch)
treec7f53b1a04c590032c022549f3186fb9b04f8358 /arch/sh/kernel/unwinder.c
parente76a0136a3cf1859fbc07f122e42293d22229558 (diff)
parentce3f7cb96e67d6518c7fc7b361a76409c3817d64 (diff)
Merge branch 'master' into sh/smp
Conflicts: arch/sh/mm/cache-sh4.c
Diffstat (limited to 'arch/sh/kernel/unwinder.c')
-rw-r--r--arch/sh/kernel/unwinder.c16
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);