From: Julien Grall <julien.grall@linaro.org>
Date: Wed, 25 Sep 2013 12:12:47 +0000 (+0100)
Subject: xen/arm: Don't dump stack when the VCPU is offline
X-Git-Tag: archive/raspbian/4.8.0-1+rpi1~1^2~6261
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=f042e3280babbe66884371eee18bd0f38b016a8e;p=xen.git

xen/arm: Don't dump stack when the VCPU is offline

When a VCPU is not yet online, the registers contain garbagge. This will
result to call randomly BUG() in show_guest_stack.

Signed-off-by: Julien Grall <julien.grall@linaro.org>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index 0e9a141905..4c0fc323ac 100644
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -612,6 +612,12 @@ static void show_guest_stack(struct vcpu *v, struct cpu_user_regs *regs)
     void *mapped;
     unsigned long *stack, addr;
 
+    if ( test_bit(_VPF_down, &v->pause_flags) )
+    {
+        printk("No stack trace, VCPU offline\n");
+        return;
+    }
+
     switch ( regs->cpsr & PSR_MODE_MASK )
     {
     case PSR_MODE_USR: