Cleaned up libposix mmap()

Now we have proper setting of errno and using pfn based mmap for both types of mmap calls.

tasks/libl4/include/l4lib/ipcdefs.h

@@ -40,7 +40,7 @@
 #define L4_IPC_TAG_BRK			17
 #define L4_IPC_TAG_READDIR		18
 #define L4_IPC_TAG_MKDIR		19
-#define L4_IPC_TAG_MMAP2		20
+#define L4_IPC_TAG_EXECVE		20
 #define L4_IPC_TAG_CHDIR		21
 #define L4_IPC_TAG_FORK			22
 #define L4_IPC_TAG_STAT			23

tasks/libposix/mmap.c

@@ -26,7 +26,7 @@ struct mmap_descriptor {
 	off_t offset;
 };
 
-void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
+static inline void *l4_mmap(void *start, size_t length, int prot, int flags, int fd, off_t pgoffset)
 {
 	/* Not enough MRs for all arguments, therefore we fill in a structure */
 	struct mmap_descriptor desc = {
@@ -35,38 +35,69 @@ void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset
 		.prot = prot,
 		.flags = flags,
 		.fd = fd,
-		.offset = offset,
+		.offset = pgoffset,
 	};
-	int err;
+	int ret;
 
 	write_mr(L4SYS_ARG0, (unsigned long)&desc);
 
-	/* Call pager with MMAP request. */
+	/* Call pager with MMAP request. Check ipc error. */
-	if ((errno = l4_sendrecv(PAGER_TID, PAGER_TID, L4_IPC_TAG_MMAP)) < 0) {
+	if ((ret = l4_sendrecv(PAGER_TID, PAGER_TID, L4_IPC_TAG_MMAP)) < 0) {
-		printf("%s: IPC Error: %d.\n", __FUNCTION__, errno);
+		printf("%s: IPC Error: %d.\n", __FUNCTION__, ret);
+		return PTR_ERR(ret);
+	}
+
+	if (IS_ERR(ret = l4_get_retval()))
+		printf("%s: MMAP Error: %d.\n", __FUNCTION__, ret);
+
+	return (void *)ret;
+}
+
+void *mmap2(void *start, size_t length, int prot, int flags, int fd, off_t pgoffset)
+{
+	void *ret = l4_mmap(start, length, prot, flags, fd, pgoffset);
+
+	if (IS_ERR(ret)) {
+		errno = -(int)ret;
 		return MAP_FAILED;
 	}
+	return 0;
+}
+
+
+void *mmap(void *start, size_t length, int prot, int flags, int fd, off_t offset)
+{
+	return mmap2(start, length, prot, flags, fd, __pfn(offset));
+}
+
+int l4_munmap(void *start, size_t length)
+{
+	int err;
+
+	write_mr(L4SYS_ARG0, (unsigned long)start);
+	write_mr(L4SYS_ARG1, length);
+
+	/* Call pager with MMAP request. */
+	if ((err = l4_sendrecv(PAGER_TID, PAGER_TID, L4_IPC_TAG_MMAP)) < 0) {
+		printf("%s: IPC Error: %d.\n", __FUNCTION__, err);
+		return err;
+	}
+
 	/* Check if syscall itself was successful */
-	if ((errno = l4_get_retval()) < 0) {
+	if ((err = l4_get_retval()) < 0) {
-		printf("%s: MMAP Error: %d.\n", __FUNCTION__, errno);
+		printf("%s: MUNMAP Error: %d.\n", __FUNCTION__, err);
-		return MAP_FAILED;
+		return err;
 	}
 	return 0;
 }
 
 int munmap(void *start, size_t length)
 {
-	write_mr(L4SYS_ARG0, (unsigned long)start);
+	int ret = l4_munmap(start, length);
-	write_mr(L4SYS_ARG1, length);
 
-	/* Call pager with MMAP request. */
+	/* If error, return positive error code */
-	if ((errno = l4_sendrecv(PAGER_TID, PAGER_TID, L4_IPC_TAG_MMAP)) < 0) {
+	if (ret < 0) {
-		printf("%s: IPC Error: %d.\n", __FUNCTION__, errno);
+		errno = -ret;
-		return -1;
-	}
-	/* Check if syscall itself was successful */
-	if ((errno = l4_get_retval()) < 0) {
-		printf("%s: MUNMAP Error: %d.\n", __FUNCTION__, errno);
 		return -1;
 	}
 	return 0;
@@ -93,6 +124,12 @@ int l4_msync(void *start, size_t length, int flags)
 
 int msync(void *start, size_t length, int flags)
 {
-	return l4_msync(start, length, flags);
+	int ret = l4_msync(start, length, flags);
+
+	if (ret < 0) {
+		errno = -ret;
+		return -1;
+	}
+	return 0;
 }
 

tasks/mm0/include/syscalls.h

@@ -24,7 +24,7 @@ struct sys_mmap_args {
 };
 
 void *sys_mmap(struct tcb *sender, void *start, size_t length, int prot,
-	       int flags, int fd, off_t offset);
+	       int flags, int fd, off_t pfn);
 
 int sys_munmap(struct tcb *sender, void *vaddr, unsigned long size);
 int sys_msync(struct tcb *task, void *start, unsigned long length, int flags);

tasks/mm0/main.c

@@ -110,17 +110,11 @@ void handle_requests(void)
 		ret = sys_lseek(sender, (int)mr[0], (off_t)mr[1], (int)mr[2]);
 		break;
 
-	case L4_IPC_TAG_MMAP2: {
+	case L4_IPC_TAG_MMAP: {
 		struct sys_mmap_args *args = (struct sys_mmap_args *)mr[0];
 		ret = (int)sys_mmap(sender, args->start, args->length, args->prot,
 			 args->flags, args->fd, args->offset);
 	}
-	case L4_IPC_TAG_MMAP: {
-		struct sys_mmap_args *args = (struct sys_mmap_args *)&mr[0];
-		ret = (int)sys_mmap(sender, args->start, args->length, args->prot,
-			 args->flags, args->fd, __pfn(args->offset));
-		break;
-	}
 	case L4_IPC_TAG_MUNMAP: {
 		ret = sys_munmap(sender, (void *)mr[0], (unsigned long)mr[1]);
 		break;