From: Tomas Hruby <tom@minix3.org>
Date: Fri, 11 Jun 2010 08:16:10 +0000 (+0000)
Subject: No linear addresses in message delivery
X-Git-Tag: v3.1.8~456
X-Git-Url: http://zhaoyanbai.com/repos/%22http:/www.isc.org/icons/index.html?a=commitdiff_plain;h=360de619c037df609ef7f5765e1092676a0e61b6;p=minix.git

No linear addresses in message delivery

- removes p_delivermsg_lin item from the process structure and code
  related to it

- as the send part, the receive does not need to use the
  PHYS_COPY_CATCH() and umap_local() couple.

- The address space of the target process is installed before
  delivermsg() is called.

- unlike the linear address, the virtual address does not change when
  paging is turned on nor after fork().
---

diff --git a/kernel/arch/i386/memory.c b/kernel/arch/i386/memory.c
index b465a8fa3..4f11d9e80 100644
--- a/kernel/arch/i386/memory.c
+++ b/kernel/arch/i386/memory.c
@@ -588,7 +588,7 @@ PRIVATE void vm_suspend(struct proc *caller, const struct proc *target,
 /*===========================================================================*
  *                              delivermsg                                *
  *===========================================================================*/
-int delivermsg(struct proc *rp)
+PUBLIC void delivermsg(struct proc *rp)
 {
 	phys_bytes addr;  
 	int r;
@@ -596,26 +596,22 @@ int delivermsg(struct proc *rp)
 	assert(rp->p_misc_flags & MF_DELIVERMSG);
 	assert(rp->p_delivermsg.m_source != NONE);
 
-	assert(rp->p_delivermsg_lin);
-	assert(rp->p_delivermsg_lin == umap_local(rp, D, rp->p_delivermsg_vir, sizeof(message)));
-
-	PHYS_COPY_CATCH(vir2phys(&rp->p_delivermsg),
-		rp->p_delivermsg_lin, sizeof(message), addr);
-
-	if(addr) {
-		vm_suspend(rp, rp, rp->p_delivermsg_lin, sizeof(message),
-			VMSTYPE_DELIVERMSG);
-		r = VMSUSPEND;
+	if (copy_msg_to_user(rp, &rp->p_delivermsg,
+				(message *) rp->p_delivermsg_vir)) {
+		printf("WARNING wrong user pointer 0x%08x from "
+				"process %s / %d\n",
+				rp->p_delivermsg_vir,
+				rp->p_name,
+				rp->p_endpoint);
+		r = EFAULT;
 	} else {
 		/* Indicate message has been delivered; address is 'used'. */
 		rp->p_delivermsg.m_source = NONE;
-		rp->p_delivermsg_lin = 0;
-
 		rp->p_misc_flags &= ~MF_DELIVERMSG;
 		r = OK;
 	}
 
-	return r;
+	rp->p_reg.retreg = r;
 }
 
 PRIVATE char *flagstr(u32_t e, const int dir)
@@ -1051,10 +1047,6 @@ PUBLIC int arch_enable_paging(struct proc * caller, const message * m_ptr)
 	if (newmap(caller, caller, ep_data.mem_map) != OK)
 		panic("arch_enable_paging: newmap failed");
 
-	FIXLINMSG(caller);
-	assert(caller->p_delivermsg_lin == umap_local(caller, D,
-				caller->p_delivermsg_vir, sizeof(message)));
-
 #ifdef CONFIG_APIC
 	/* if local APIC is enabled */
 	if (lapic_addr) {
diff --git a/kernel/proc.c b/kernel/proc.c
index dc4eda719..809597dc4 100644
--- a/kernel/proc.c
+++ b/kernel/proc.c
@@ -159,13 +159,7 @@ check_misc_flags:
 		else if (proc_ptr->p_misc_flags & MF_DELIVERMSG) {
 			TRACE(VF_SCHEDULING, printf("delivering to %s / %d\n",
 				proc_ptr->p_name, proc_ptr->p_endpoint););
-			if(delivermsg(proc_ptr) == VMSUSPEND) {
-				TRACE(VF_SCHEDULING,
-					printf("suspending %s / %d\n",
-					proc_ptr->p_name,
-					proc_ptr->p_endpoint););
-				assert(!proc_is_runnable(proc_ptr));
-			}
+			delivermsg(proc_ptr);
 		}
 		else if (proc_ptr->p_misc_flags & MF_SC_DEFER) {
 			/* Perform the system call that we deferred earlier. */
@@ -605,12 +599,10 @@ PUBLIC int mini_send(
 /*===========================================================================*
  *				mini_receive				     * 
  *===========================================================================*/
-PRIVATE int mini_receive(
-  register struct proc *caller_ptr,	/* process trying to get message */
-  endpoint_t src_e,			/* which message source is wanted */
-  message *m_ptr,			/* pointer to message buffer */
-  const int flags
-)
+PRIVATE int mini_receive(struct proc * caller_ptr,
+			int src_e, /* which message source is wanted */
+			message * m_buff_usr, /* pointer to message buffer */
+			const int flags)
 {
 /* A process or task wants to get a message.  If a message is already queued,
  * acquire it and deblock the sender.  If no message from the desired source
@@ -620,18 +612,11 @@ PRIVATE int mini_receive(
   sys_map_t *map;
   bitchunk_t *chunk;
   int i, r, src_id, src_proc_nr, src_p;
-  phys_bytes linaddr;
 
   assert(!(caller_ptr->p_misc_flags & MF_DELIVERMSG));
 
-  if(!(linaddr = umap_local(caller_ptr, D, (vir_bytes) m_ptr,
-	sizeof(message)))) {
-	return EFAULT;
-  }
-
   /* This is where we want our message. */
-  caller_ptr->p_delivermsg_lin = linaddr;
-  caller_ptr->p_delivermsg_vir = (vir_bytes) m_ptr;
+  caller_ptr->p_delivermsg_vir = (vir_bytes) m_buff_usr;
 
   if(src_e == ANY) src_p = ANY;
   else
diff --git a/kernel/proc.h b/kernel/proc.h
index d84f17aec..544fd8a62 100644
--- a/kernel/proc.h
+++ b/kernel/proc.h
@@ -56,7 +56,6 @@ struct proc {
   message p_sendmsg;		/* Message from this process if SENDING */
   message p_delivermsg;		/* Message for this process if MF_DELIVERMSG */
   vir_bytes p_delivermsg_vir;	/* Virtual addr this proc wants message at */
-  vir_bytes p_delivermsg_lin;	/* Linear addr this proc wants message at */
 
   /* If handler functions detect a process wants to do something with
    * memory that isn't present, VM has to fix it. Until it has asked
diff --git a/kernel/proto.h b/kernel/proto.h
index 727d987c9..b727eab22 100644
--- a/kernel/proto.h
+++ b/kernel/proto.h
@@ -176,7 +176,7 @@ _PROTOTYPE( int arch_do_vmctl, (message *m_ptr, struct proc *p));
 _PROTOTYPE( int vm_contiguous, (const struct proc *targetproc, vir_bytes vir_buf, size_t count));
 _PROTOTYPE( void proc_stacktrace, (struct proc *proc)	         );
 _PROTOTYPE( int vm_lookup, (const struct proc *proc, vir_bytes virtual, vir_bytes *result, u32_t *ptent));
-_PROTOTYPE( int delivermsg, (struct proc *target));
+_PROTOTYPE( void delivermsg, (struct proc *target));
 _PROTOTYPE( void arch_do_syscall, (struct proc *proc)			);
 _PROTOTYPE( int arch_phys_map, (int index, phys_bytes *addr,
 	phys_bytes *len, int *flags));
diff --git a/kernel/system/do_exec.c b/kernel/system/do_exec.c
index e6fe9892f..85aaf1a3b 100644
--- a/kernel/system/do_exec.c
+++ b/kernel/system/do_exec.c
@@ -29,7 +29,6 @@ PUBLIC int do_exec(struct proc * caller, message * m_ptr)
 
   if(rp->p_misc_flags & MF_DELIVERMSG) {
 	rp->p_misc_flags &= ~MF_DELIVERMSG;
-	rp->p_delivermsg_lin = 0;
   }
 
   /* Save command name for debugging, ps(1) output, etc. */
diff --git a/kernel/system/do_fork.c b/kernel/system/do_fork.c
index 302e7262b..4a1180cc6 100644
--- a/kernel/system/do_fork.c
+++ b/kernel/system/do_fork.c
@@ -109,7 +109,6 @@ PUBLIC int do_fork(struct proc * caller, message * m_ptr)
 
   /* Install new map */
   r = newmap(caller, rpc, map_ptr);
-  FIXLINMSG(rpc);
 
   /* Don't schedule process in VM mode until it has a new pagetable. */
   if(m_ptr->PR_FORK_FLAGS & PFF_VMINHIBIT) {
diff --git a/kernel/vm.h b/kernel/vm.h
index 43461e68f..404537338 100644
--- a/kernel/vm.h
+++ b/kernel/vm.h
@@ -7,8 +7,6 @@
 #define EFAULT_SRC	(-995)
 #define EFAULT_DST	(-994)
 
-#define FIXLINMSG(prp) { prp->p_delivermsg_lin = umap_local(prp, D, prp->p_delivermsg_vir, sizeof(message)); }
-
 #define PHYS_COPY_CATCH(src, dst, size, a) {	\
 	catch_pagefaults++;			\
 	a = phys_copy(src, dst, size);		\