sandbox: Return error code from read/write/seek

The existing API for these functions is different from the rest of
U-Boot, in that any error code must be obtained from the errno variable
on failure. This variable is part of the C library, so accessing it
outside of the special 'sandbox' shim-functions is not ideal.

Adjust the API to return an error code, to avoid this. Update existing
uses to check for any negative value, rather than just -1.

Signed-off-by: Simon Glass <sjg@chromium.org>

1 files changed, 21 insertions, 3 deletions

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index da96ebe43c9..f5c9a8aecf2 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -47,12 +47,24 @@ struct os_mem_hdr {
 
 ssize_t os_read(int fd, void *buf, size_t count)
 {
-	return read(fd, buf, count);
+	ssize_t ret;
+
+	ret = read(fd, buf, count);
+	if (ret == -1)
+		return -errno;
+
+	return ret;
 }
 
 ssize_t os_write(int fd, const void *buf, size_t count)
 {
-	return write(fd, buf, count);
+	ssize_t ret;
+
+	ret = write(fd, buf, count);
+	if (ret == -1)
+		return -errno;
+
+	return ret;
 }
 
 int os_printf(const char *fmt, ...)
@@ -69,6 +81,8 @@ int os_printf(const char *fmt, ...)
 
 off_t os_lseek(int fd, off_t offset, int whence)
 {
+	off_t ret;
+
 	if (whence == OS_SEEK_SET)
 		whence = SEEK_SET;
 	else if (whence == OS_SEEK_CUR)
@@ -77,7 +91,11 @@ off_t os_lseek(int fd, off_t offset, int whence)
 		whence = SEEK_END;
 	else
 		os_exit(1);
-	return lseek(fd, offset, whence);
+	ret = lseek(fd, offset, whence);
+	if (ret == -1)
+		return -errno;
+
+	return ret;
 }
 
 int os_open(const char *pathname, int os_flags)