From: Andrew Cooper <andrew.cooper3@citrix.com>
Date: Thu, 21 May 2020 08:19:33 +0000 (+0100)
Subject: xen/trace: Don't dump offline CPUs in debugtrace_dump_worker()
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~210
X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=abf378e6483195b98a3f32e2c9d017e0eeeb275f;p=xen.git

xen/trace: Don't dump offline CPUs in debugtrace_dump_worker()

The 'T' debugkey reliably wedges on one of my systems, which has a sparse
APIC_ID layout due to a non power-of-2 number of cores per socket.  The
per_cpu(dt_cpu_data, cpu) calcution falls over the deliberately non-canonical
poison value.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---

diff --git a/xen/common/debugtrace.c b/xen/common/debugtrace.c
index c21ec99ee0..f3794b9453 100644
--- a/xen/common/debugtrace.c
+++ b/xen/common/debugtrace.c
@@ -95,7 +95,7 @@ static void debugtrace_dump_worker(void)
 
     debugtrace_dump_buffer(dt_data, "global");
 
-    for ( cpu = 0; cpu < nr_cpu_ids; cpu++ )
+    for_each_online_cpu ( cpu )
     {
         char buf[16];