From: Juergen Gross <jgross@suse.com>
Date: Mon, 29 Jul 2019 04:36:24 +0000 (+0200)
Subject: xen: don't longjmp() after domain_crash() in check_wakeup_from_wait()
X-Git-Tag: archive/raspbian/4.14.0+80-gd101b417b7-1+rpi1^2~63^2~1840
X-Git-Url: https://dgit.raspbian.org/%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22man:///%22http:/www.example.com/cgi/%22https:/%22bookmarks:/%22man:/?a=commitdiff_plain;h=3ef59a85411eb7391876bed6f5c7541126e2de25;p=xen.git

xen: don't longjmp() after domain_crash() in check_wakeup_from_wait()

Continuing on the stack saved by __prepare_to_wait() on the wrong cpu
is rather dangerous.

Instead of doing so just call the scheduler again as it already is
happening in the similar case in __prepare_to_wait() when doing the
setjmp() would be wrong.

Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
---

diff --git a/xen/common/wait.c b/xen/common/wait.c
index 3fc5f68611..24716e7676 100644
--- a/xen/common/wait.c
+++ b/xen/common/wait.c
@@ -196,6 +196,11 @@ void check_wakeup_from_wait(void)
     {
         gdprintk(XENLOG_ERR, "vcpu affinity lost\n");
         domain_crash(curr->domain);
+
+        /* Re-initiate scheduler and don't longjmp(). */
+        raise_softirq(SCHEDULE_SOFTIRQ);
+        for ( ; ; )
+            do_softirq();
     }
 
     /*