Merge tag 'v3.15-rc1' into patchwork

Linux 3.15-rc1

* tag 'v3.15-rc1': (12180 commits)
  Linux 3.15-rc1
  mm: Initialize error in shmem_file_aio_read()
  cifs: Use min_t() when comparing "size_t" and "unsigned long"
  sym53c8xx_2: Set DID_REQUEUE return code when aborting squeue
  powerpc: Don't try to set LPCR unless we're in hypervisor mode
  futex: update documentation for ordering guarantees
  ceph: fix pr_fmt() redefinition
  vti: don't allow to add the same tunnel twice
  gre: don't allow to add the same tunnel twice
  drivers: net: xen-netfront: fix array initialization bug
  missing bits of "splice: fix racy pipe->buffers uses"
  cifs: fix the race in cifs_writev()
  ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
  pktgen: be friendly to LLTX devices
  r8152: check RTL8152_UNPLUG
  net: sun4i-emac: add promiscuous support
  net/apne: replace IS_ERR and PTR_ERR with PTR_ERR_OR_ZERO
  blackfin: cleanup board files
  bf609: clock: drop unused clock bit set/clear functions
  Blackfin: bf537: rename "CONFIG_ADT75"
  ...

1 files changed, 41 insertions, 5 deletions

diff --git a/arch/x86/kernel/dumpstack_32.c b/arch/x86/kernel/dumpstack_32.c
index f2a1770ca176..5abd4cd4230c 100644
--- a/arch/x86/kernel/dumpstack_32.c
+++ b/arch/x86/kernel/dumpstack_32.c
@@ -16,12 +16,35 @@
 
 #include <asm/stacktrace.h>
 
+static void *is_irq_stack(void *p, void *irq)
+{
+	if (p < irq || p >= (irq + THREAD_SIZE))
+		return NULL;
+	return irq + THREAD_SIZE;
+}
+
+
+static void *is_hardirq_stack(unsigned long *stack, int cpu)
+{
+	void *irq = per_cpu(hardirq_stack, cpu);
+
+	return is_irq_stack(stack, irq);
+}
+
+static void *is_softirq_stack(unsigned long *stack, int cpu)
+{
+	void *irq = per_cpu(softirq_stack, cpu);
+
+	return is_irq_stack(stack, irq);
+}
 
 void dump_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long *stack, unsigned long bp,
 		const struct stacktrace_ops *ops, void *data)
 {
+	const unsigned cpu = get_cpu();
 	int graph = 0;
+	u32 *prev_esp;
 
 	if (!task)
 		task = current;
@@ -30,7 +53,7 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 		unsigned long dummy;
 
 		stack = &dummy;
-		if (task && task != current)
+		if (task != current)
 			stack = (unsigned long *)task->thread.sp;
 	}
 
@@ -39,18 +62,31 @@ void dump_trace(struct task_struct *task, struct pt_regs *regs,
 
 	for (;;) {
 		struct thread_info *context;
+		void *end_stack;
+
+		end_stack = is_hardirq_stack(stack, cpu);
+		if (!end_stack)
+			end_stack = is_softirq_stack(stack, cpu);
 
-		context = (struct thread_info *)
-			((unsigned long)stack & (~(THREAD_SIZE - 1)));
-		bp = ops->walk_stack(context, stack, bp, ops, data, NULL, &graph);
+		context = task_thread_info(task);
+		bp = ops->walk_stack(context, stack, bp, ops, data,
+				     end_stack, &graph);
 
-		stack = (unsigned long *)context->previous_esp;
+		/* Stop if not on irq stack */
+		if (!end_stack)
+			break;
+
+		/* The previous esp is saved on the bottom of the stack */
+		prev_esp = (u32 *)(end_stack - THREAD_SIZE);
+		stack = (unsigned long *)*prev_esp;
 		if (!stack)
 			break;
+
 		if (ops->stack(data, "IRQ") < 0)
 			break;
 		touch_nmi_watchdog();
 	}
+	put_cpu();
 }
 EXPORT_SYMBOL(dump_trace);