Module Name: src
Committed By: ad
Date: Mon Jan 13 11:40:15 UTC 2020
Modified Files:
src/sys/arch/amd64/amd64: locore.S
Log Message:
It looks like Xen cpu_hatch() calls cpu_switchto() with prevlwp=NULL,
instead of calling idle_loop() directly. I can't test a change to
cpu_hatch() right now so allow for prevlwp=NULL.
To generate a diff of this commit:
cvs rdiff -u -r1.198 -r1.199 src/sys/arch/amd64/amd64/locore.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/amd64/amd64/locore.S
diff -u src/sys/arch/amd64/amd64/locore.S:1.198 src/sys/arch/amd64/amd64/locore.S:1.199
--- src/sys/arch/amd64/amd64/locore.S:1.198 Thu Jan 9 00:42:24 2020
+++ src/sys/arch/amd64/amd64/locore.S Mon Jan 13 11:40:15 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: locore.S,v 1.198 2020/01/09 00:42:24 manu Exp $ */
+/* $NetBSD: locore.S,v 1.199 2020/01/13 11:40:15 ad Exp $ */
/*
* Copyright-o-rama!
@@ -1079,10 +1079,14 @@ ENTRY(cpu_switchto)
movq %rdi,%r13 /* oldlwp */
movq %rsi,%r12 /* newlwp */
+ testq %r13,%r13 /* oldlwp = NULL ? */
+ jz .Lskip_save
+
/* Save old context. */
movq L_PCB(%r13),%rax
movq %rsp,PCB_RSP(%rax)
movq %rbp,PCB_RBP(%rax)
+.Lskip_save:
/* Switch to newlwp's stack. */
movq L_PCB(%r12),%r14
