From: Ben Gras <ben@minix3.org>
Date: Sun, 4 Jul 2010 23:09:24 +0000 (+0000)
Subject: kernel: use MF_KCALL_RESUME instead of RTS_VMREQUEST for memcopy retry.
X-Git-Tag: v3.1.8~288
X-Git-Url: http://zhaoyanbai.com/repos/doc/mandoc_char.7.html?a=commitdiff_plain;h=545054c608daa6b05a891305ffd1ec0dc7470eab;p=minix.git

kernel: use MF_KCALL_RESUME instead of RTS_VMREQUEST for memcopy retry.

solves tracker item 499, submitted by Roman Ignatov.
---

diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index cdff15981..b5e9f4add 100644
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -570,6 +570,8 @@ PRIVATE void vm_suspend(struct proc *caller, const struct proc *target,
 	 */								
 	assert(!RTS_ISSET(caller, RTS_VMREQUEST));
 	assert(!RTS_ISSET(target, RTS_VMREQUEST));
+	assert(!(caller->p_misc_flags & MF_KCALL_RESUME));
+	assert(!(target->p_misc_flags & MF_KCALL_RESUME));
 
 	RTS_SET(caller, RTS_VMREQUEST);
 
@@ -819,9 +821,8 @@ int vmcheck;			/* if nonzero, can return VMSUSPEND */
   if(vm_running) {
 	int r;
 
-	if(caller && RTS_ISSET(caller, RTS_VMREQUEST)) {
+	if(caller && (caller->p_misc_flags & MF_KCALL_RESUME)) {
 		assert(caller->p_vmrequest.vmresult != VMSUSPEND);
-		RTS_UNSET(caller, RTS_VMREQUEST);
 		if(caller->p_vmrequest.vmresult != OK) {
 	  		return caller->p_vmrequest.vmresult;
 		}
diff --git a/kernel/system.c b/kernel/system.c
index ac89638cd..e3a1b769a 100644
--- a/kernel/system.c
+++ b/kernel/system.c
@@ -591,11 +591,14 @@ PUBLIC void kernel_call_resume(struct proc *caller)
 			caller->p_rts_flags, caller->p_misc_flags);
 	 */
 
+	/* re-execute the kernel call, with MF_KCALL_RESUME still set so
+	 * the call knows this is a retry.
+	 */
+	result = kernel_call_dispatch(caller, &caller->p_vmrequest.saved.reqmsg);
 	/*
 	 * we are resuming the kernel call so we have to remove this flag so it
 	 * can be set again
 	 */
 	caller->p_misc_flags &= ~MF_KCALL_RESUME;
-	result = kernel_call_dispatch(caller, &caller->p_vmrequest.saved.reqmsg);
 	kernel_call_finish(caller, &caller->p_vmrequest.saved.reqmsg, result);
 }