From: Ben Gras <ben@minix3.org>
Date: Wed, 3 Jun 2009 15:28:13 +0000 (+0000)
Subject: only switch pagetable if necessary and it's different for copying messages
X-Git-Tag: v3.1.4~13
X-Git-Url: http://zhaoyanbai.com/repos/?a=commitdiff_plain;h=9d56ac3fc9832c3657891ec4aa6680c5a891df78;p=minix.git

only switch pagetable if necessary and it's different for copying messages
---

diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index 44896b90f..1c3f6d6c6 100644
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -704,11 +704,14 @@ u32_t read_cr3(void)
 phys_bytes arch_switch_copymsg(struct proc *rp, message *m, phys_bytes lin)
 {
 	phys_bytes r;
-	if(rp->p_seg.p_cr3) {
+	int u = 0;
+	if(!intr_disabled()) { lock; u = 1; }
+	if(rp->p_seg.p_cr3 && ptproc != rp) {
 		vm_set_cr3(rp->p_seg.p_cr3);
 		ptproc = rp;
 	}
 	r = phys_copy(vir2phys(m), lin, sizeof(message));
+	if(u) { unlock; }
 }
 
 /*===========================================================================*