From: Andrii Anisov <andrii_anisov@epam.com>
Date: Wed, 8 May 2019 09:59:38 +0000 (+0300)
Subject: xen:arm: we never get into schedule_tail() with prev==current
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~2232
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks://%22Dat/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22Dat?a=commitdiff_plain;h=5945b57b055abcab803d23974e95c3657ef597fb;p=xen.git

xen:arm: we never get into schedule_tail() with prev==current

ARM's schedule_tail() is called from two places: context_switch() and
continue_new_vcpu(). Both functions are always called with
prev!=current. So replace the correspondent check in schedule_tail()
with ASSERT() which is the development (debug) build guard.

Signed-off-by: Andrii Anisov <andrii_anisov@epam.com>
Reviewed-by: Dario Faggioli <dfaggioli@suse.com>
Acked-by: Julien Grall <julien.grall@arm.com>
---

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index 915ae0b4c6..ff330b35e6 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -305,6 +305,8 @@ static void update_runstate_area(struct vcpu *v)
 
 static void schedule_tail(struct vcpu *prev)
 {
+    ASSERT(prev != current);
+
     ctxt_switch_from(prev);
 
     ctxt_switch_to(current);
@@ -313,8 +315,7 @@ static void schedule_tail(struct vcpu *prev)
 
     context_saved(prev);
 
-    if ( prev != current )
-        update_runstate_area(current);
+    update_runstate_area(current);
 
     /* Ensure that the vcpu has an up-to-date time base. */
     update_vcpu_system_time(current);