Remove unnecessary mmap in memory_map ipc

This is similar patch as master e684e4ca6fed709c14d79d8d81f254aa48e1c65a
but for whole IPC.

Signed-off-by: Jan Friesse <jfriesse@redhat.com>
Reviewed-by: Fabio M. Di Nitto <fdinitto@redhat.com>

exec/coroipcs.c

@@ -222,7 +222,6 @@ memory_map (
 	void **buf)
 {
 	int32_t fd;
-	void *addr_orig;
 	void *addr;
 	int32_t res;
 
@@ -239,18 +238,10 @@ memory_map (
 		goto error_close_unlink;
 	}
 
-	addr_orig = mmap (NULL, bytes, PROT_NONE,
-		MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+	addr = mmap (NULL, bytes, PROT_READ | PROT_WRITE,
+		MAP_SHARED, fd, 0);
 
-	if (addr_orig == MAP_FAILED) {
-		goto error_close_unlink;
-	}
-
-	addr = mmap (addr_orig, bytes, PROT_READ | PROT_WRITE,
-		MAP_FIXED | MAP_SHARED, fd, 0);
-
-	if (addr != addr_orig) {
-		munmap(addr_orig, bytes);
+	if (addr == MAP_FAILED) {
 		goto error_close_unlink;
 	}
 #if (defined COROSYNC_BSD && defined MADV_NOSYNC)
@@ -261,7 +252,7 @@ memory_map (
 	if (res) {
 		return (-1);
 	}
-	*buf = addr_orig;
+	*buf = addr;
 	return (0);
 
 error_close_unlink:

lib/coroipcc.c

@@ -405,7 +405,6 @@ static int
 memory_map (char *path, const char *file, void **buf, size_t bytes)
 {
 	int32_t fd;
-	void *addr_orig;
 	void *addr;
 	int32_t res;
 	char *buffer;
@@ -451,28 +450,22 @@ retry_write:
 	}
 	free (buffer);
 
-	addr_orig = mmap (NULL, bytes, PROT_NONE,
-		MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
-
-	if (addr_orig == MAP_FAILED) {
-		goto error_close_unlink;
-	}
 
-	addr = mmap (addr_orig, bytes, PROT_READ | PROT_WRITE,
-		MAP_FIXED | MAP_SHARED, fd, 0);
+	addr = mmap (NULL, bytes, PROT_READ | PROT_WRITE,
+		MAP_SHARED, fd, 0);
 
-	if (addr != addr_orig) {
+	if (addr == MAP_FAILED) {
 		goto error_close_unlink;
 	}
 #if (defined COROSYNC_BSD && defined MADV_NOSYNC)
-	madvise(addr_orig, bytes, MADV_NOSYNC);
+	madvise(addr, bytes, MADV_NOSYNC);
 #endif
 
 	res = close (fd);
 	if (res) {
 		return (-1);
 	}
-	*buf = addr_orig;
+	*buf = addr;
 
 	return 0;