arch: sandbox: Add function to create temporary files

When working with sparse data buffers that may be larger than the address
space, it is convenient to work with files instead. Add a function to create
temporary files of a certain size.

Signed-off-by: Sean Anderson <seanga2@gmail.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/arch/sandbox/cpu/os.c b/arch/sandbox/cpu/os.c
index 85d0d6a..8847c4c 100644
--- a/arch/sandbox/cpu/os.c
+++ b/arch/sandbox/cpu/os.c
@@ -282,6 +282,23 @@ int os_persistent_file(char *buf, int maxsize, const char *fname)
 	return 0;
 }
 
+int os_mktemp(char *fname, off_t size)
+{
+	int fd;
+
+	fd = mkostemp(fname, O_CLOEXEC);
+	if (fd < 0)
+		return -errno;
+
+	if (unlink(fname) < 0)
+		return -errno;
+
+	if (ftruncate(fd, size))
+		return -errno;
+
+	return fd;
+}
+
 /* Restore tty state when we exit */
 static struct termios orig_term;
 static bool term_setup;