X-Git-Url: http://git.agner.ch/gitweb/?p=linux-drm-fsl-dcu.git;a=blobdiff_plain;f=arch%2Fum%2Fos-Linux%2Fmem.c;h=f1ea169db85e174cf2d6998043bce9d655eef0cd;hp=c6432e7292411de1ea2006aabf97a13c3a7fa4eb;hb=f8abea8f8c24ecdad6d6861bffb912f23f2741cd;hpb=7c8ce71b092425f1e938285cab2a679c09444d9b

diff --git a/arch/um/os-Linux/mem.c b/arch/um/os-Linux/mem.c
index c6432e729241..f1ea169db85e 100644
--- a/arch/um/os-Linux/mem.c
+++ b/arch/um/os-Linux/mem.c
@@ -20,7 +20,13 @@
 
 #include <sys/param.h>
 
+/* Modified by which_tmpdir, which is called during early boot */
 static char *default_tmpdir = "/tmp";
+
+/*
+ *  Modified when creating the physical memory file and when checking
+ * the tmp filesystem for usability, both happening during early boot.
+ */
 static char *tempdir = NULL;
 
 static void __init find_tempdir(void)
@@ -29,7 +35,8 @@ static void __init find_tempdir(void)
 	int i;
 	char *dir = NULL;
 
-	if(tempdir != NULL) return;	/* We've already been called */
+	if(tempdir != NULL) /* We've already been called */
+		return;
 	for(i = 0; dirs[i]; i++){
 		dir = getenv(dirs[i]);
 		if((dir != NULL) && (*dir != '\0'))
@@ -55,7 +62,7 @@ static void __init find_tempdir(void)
  */
 static int next(int fd, char *buf, int size, char c)
 {
-	int n;
+	int n, len;
 	char *ptr;
 
 	while((ptr = strchr(buf, c)) == NULL){
@@ -69,10 +76,21 @@ static int next(int fd, char *buf, int size, char c)
 	}
 
 	ptr++;
-	memmove(buf, ptr, strlen(ptr) + 1);
+	len = strlen(ptr);
+	memmove(buf, ptr, len + 1);
+
+	/* Refill the buffer so that if there's a partial string that we care
+	 * about, it will be completed, and we can recognize it.
+	 */
+	n = read(fd, &buf[len], size - len - 1);
+	if(n < 0)
+		return -errno;
+
+	buf[len + n] = '\0';
 	return 1;
 }
 
+/* which_tmpdir is called only during early boot */
 static int checked_tmpdir = 0;
 
 /* Look for a tmpfs mounted at /dev/shm.  I couldn't find a cleaner
@@ -104,14 +122,14 @@ static void which_tmpdir(void)
 	}
 
 	while(1){
-		found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
+		found = next(fd, buf, ARRAY_SIZE(buf), ' ');
 		if(found != 1)
 			break;
 
 		if(!strncmp(buf, "/dev/shm", strlen("/dev/shm")))
 			goto found;
 
-		found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), '\n');
+		found = next(fd, buf, ARRAY_SIZE(buf), '\n');
 		if(found != 1)
 			break;
 	}
@@ -122,20 +140,24 @@ err:
 	else if(found < 0)
 		printf("read returned errno %d\n", -found);
 
+out:
+	close(fd);
+
 	return;
 
 found:
-	found = next(fd, buf, sizeof(buf) / sizeof(buf[0]), ' ');
+	found = next(fd, buf, ARRAY_SIZE(buf), ' ');
 	if(found != 1)
 		goto err;
 
 	if(strncmp(buf, "tmpfs", strlen("tmpfs"))){
 		printf("not tmpfs\n");
-		return;
+		goto out;
 	}
 
 	printf("OK\n");
 	default_tmpdir = "/dev/shm";
+	goto out;
 }
 
 /*
@@ -172,7 +194,7 @@ int make_tempfile(const char *template, char **out_tempname, int do_unlink)
 	} else {
 		free(tempname);
 	}
-	return(fd);
+	return fd;
 out:
 	free(tempname);
 	return -1;
@@ -200,8 +222,11 @@ int create_tmp_file(unsigned long long len)
 		exit(1);
 	}
 
-        if (lseek64(fd, len, SEEK_SET) < 0) {
- 		perror("os_seek_file");
+	/* Seek to len - 1 because writing a character there will
+	 * increase the file size by one byte, to the desired length.
+	 */
+	if (lseek64(fd, len - 1, SEEK_SET) < 0) {
+		perror("os_seek_file");
 		exit(1);
 	}
 
@@ -214,7 +239,7 @@ int create_tmp_file(unsigned long long len)
 		exit(1);
 	}
 
-	return(fd);
+	return fd;
 }
 
 int create_mem_file(unsigned long long len)
@@ -228,7 +253,7 @@ int create_mem_file(unsigned long long len)
 		errno = -err;
 		perror("exec_close");
 	}
-	return(fd);
+	return fd;
 }