Merge tag 'v4.15-rc6' into patchwork

Linux 4.15-rc6

* tag 'v4.15-rc6': (734 commits)
  Linux 4.15-rc6
  MAINTAINERS: mark arch/blackfin/ and its gubbins as orphaned
  x86/ldt: Make LDT pgtable free conditional
  x86/ldt: Plug memory leak in error path
  x86/mm: Remove preempt_disable/enable() from __native_flush_tlb()
  x86/smpboot: Remove stale TLB flush invocations
  objtool: Fix seg fault with clang-compiled objects
  objtool: Fix seg fault caused by missing parameter
  kbuild: add '-fno-stack-check' to kernel build options
  timerqueue: Document return values of timerqueue_add/del()
  timers: Invoke timer_start_debug() where it makes sense
  nohz: Prevent a timer interrupt storm in tick_nohz_stop_sched_tick()
  timers: Reinitialize per cpu bases on hotplug
  timers: Use deferrable base independent of base::nohz_active
  genirq/msi, x86/vector: Prevent reservation mode for non maskable MSI
  genirq/irqdomain: Rename early argument of irq_domain_activate_irq()
  x86/vector: Use IRQD_CAN_RESERVE flag
  genirq: Introduce IRQD_CAN_RESERVE flag
  genirq/msi: Handle reactivation only on success
  gpio: brcmstb: Make really use of the new lockdep class
  ...

1 files changed, 5 insertions, 1 deletions

diff --git a/arch/x86/kernel/stacktrace.c b/arch/x86/kernel/stacktrace.c
index 77835bc021c7..20161ef53537 100644
--- a/arch/x86/kernel/stacktrace.c
+++ b/arch/x86/kernel/stacktrace.c
@@ -164,8 +164,12 @@ int save_stack_trace_tsk_reliable(struct task_struct *tsk,
 {
 	int ret;
 
+	/*
+	 * If the task doesn't have a stack (e.g., a zombie), the stack is
+	 * "reliably" empty.
+	 */
 	if (!try_get_task_stack(tsk))
-		return -EINVAL;
+		return 0;
 
 	ret = __save_stack_trace_reliable(trace, tsk);