util/nvmutil: handle errno after file read

errno shouldn't be set, after reading a file successfully.

if it is, that's a bug. handle it accordingly.

Signed-off-by: Leah Rowe <leah@libreboot.org>

1 files changed, 7 insertions, 3 deletions

diff --git a/util/nvmutil/nvmutil.c b/util/nvmutil/nvmutil.c
index ea799997..bff8bab0 100644
--- a/util/nvmutil/nvmutil.c
+++ b/util/nvmutil/nvmutil.c
@@ -299,6 +299,9 @@ read_gbe_part(int p, int invert)
 			break;
 	}
 
+	if (errno)
+		err(errno, "Unhandled error on read of file '%s'", fname);
+
 	swap(p ^ invert); /* handle big-endian host CPU */
 }
 
@@ -420,16 +423,17 @@ read_urandom(uint8_t *rnum, size_t rsize)
 		    rsize, retry, "read"))
 			break;
 	}
+
+	if (errno)
+		err(errno, "Unhandled error on read of file '/dev/urandom'");
 }
 
 static int
 check_read_or_die(const char *rpath, ssize_t rval, size_t rsize,
     int retry, const char *readtype)
 {
-	if (rval == (ssize_t) rsize) {
-		errno = 0;
+	if (rval == (ssize_t) rsize)
 		return 1; /* Successful read */
-	}
 
 	if (rval != -1)
 		err(ECANCELED, "Short %s, %zd bytes, on file: %s",