Make errno a positive value

Normally errno contains a positive error value. A certain unnamed developer
mixed this up while implementing U-Boot-v2. Also, normally errno is never
set to zero by any library function.
This patch fixes this.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

4 files changed, 11 insertions, 13 deletions

diff --git a/commands/crc.c b/commands/crc.c
index df229410f6..a0d3af63fa 100644
--- a/commands/crc.c
+++ b/commands/crc.c
@@ -48,7 +48,7 @@ static int file_crc(char* filename, ulong start, ulong size, ulong *crc,
 
 	if (start > 0) {
 		ret = lseek(fd, start, SEEK_SET);
-		if (ret == -1) {
+		if (ret < 0) {
 			perror("lseek");
 			goto out;
 		}
diff --git a/commands/ls.c b/commands/ls.c
index c98d2dad57..ad609f3133 100644
--- a/commands/ls.c
+++ b/commands/ls.c
@@ -49,7 +49,7 @@ int ls(const char *path, ulong flags)
 	string_list_init(&sl);
 
 	if (stat(path, &s))
-		return errno;
+		return -errno;
 
 	if (flags & LS_SHOWARG && s.st_mode & S_IFDIR)
 		printf("%s:\n", path);
@@ -61,7 +61,7 @@ int ls(const char *path, ulong flags)
 
 	dir = opendir(path);
 	if (!dir)
-		return errno;
+		return -errno;
 
 	while ((d = readdir(dir))) {
 		sprintf(tmp, "%s/%s", path, d->d_name);
@@ -85,7 +85,7 @@ int ls(const char *path, ulong flags)
 
 	dir = opendir(path);
 	if (!dir) {
-		errno = -ENOENT;
+		errno = ENOENT;
 		return -ENOENT;
 	}
 
diff --git a/commands/mem.c b/commands/mem.c
index d8e90e056f..f32e5d8299 100644
--- a/commands/mem.c
+++ b/commands/mem.c
@@ -122,7 +122,7 @@ static int open_and_lseek(const char *filename, int mode, off_t pos)
 		return fd;
 
 	ret = lseek(fd, pos, SEEK_SET);
-	if (ret == -1) {
+	if (ret < 0) {
 		perror("lseek");
 		close(fd);
 		return ret;
@@ -170,7 +170,6 @@ static int do_mem_md(int argc, char *argv[])
 	char *filename = DEVMEM;
 	int mode = O_RWSIZE_4;
 
-	errno = 0;
 	if (mem_parse_options(argc, argv, "bwls:", &mode, &filename, NULL) < 0)
 		return 1;
 
@@ -207,7 +206,7 @@ static int do_mem_md(int argc, char *argv[])
 out:
 	close(fd);
 
-	return errno;
+	return ret ? 1 : 0;
 }
 
 static const __maybe_unused char cmd_md_help[] =
@@ -243,8 +242,6 @@ static int do_mem_mw(int argc, char *argv[])
 	int mode = O_RWSIZE_4;
 	ulong adr;
 
-	errno = 0;
-
 	if (mem_parse_options(argc, argv, "bwld:", &mode, NULL, &filename) < 0)
 		return 1;
 
@@ -279,12 +276,13 @@ static int do_mem_mw(int argc, char *argv[])
 			perror("write");
 			break;
 		}
+		ret = 0;
 		optind++;
 	}
 
 	close(fd);
 
-	return errno;
+	return ret ? 1 : 0;
 }
 
 static const __maybe_unused char cmd_mw_help[] =
diff --git a/commands/saveenv.c b/commands/saveenv.c
index a4b279676d..549fcd4279 100644
--- a/commands/saveenv.c
+++ b/commands/saveenv.c
@@ -54,7 +54,7 @@ static int do_saveenv(int argc, char *argv[])
 	ret = protect(fd, ~0, 0, 0);
 
 	/* ENOSYS is no error here, many devices do not need it */
-	if (ret && errno != -ENOSYS) {
+	if (ret && errno != ENOSYS) {
 		printf("could not unprotect %s: %s\n", filename, errno_str());
 		close(fd);
 		return 1;
@@ -63,7 +63,7 @@ static int do_saveenv(int argc, char *argv[])
 	ret = erase(fd, ~0, 0);
 
 	/* ENOSYS is no error here, many devices do not need it */
-	if (ret && errno != -ENOSYS) {
+	if (ret && errno != ENOSYS) {
 		printf("could not erase %s: %s\n", filename, errno_str());
 		close(fd);
 		return 1;
@@ -82,7 +82,7 @@ static int do_saveenv(int argc, char *argv[])
 	ret = protect(fd, ~0, 0, 1);
 
 	/* ENOSYS is no error here, many devices do not need it */
-	if (ret && errno != -ENOSYS) {
+	if (ret && errno != ENOSYS) {
 		printf("could not protect %s: %s\n", filename, errno_str());
 		close(fd);
 		return 1;