On a Thursday in 2020, Daniel P. Berrangé wrote:
On Thu, Feb 27, 2020 at 11:06:21AM +0100, Philippe Mathieu-Daudé wrote:Use GLib g_file_open_tmp() instead of getenv + snprintf + mkstemp.Signed-off-by: Philippe Mathieu-Daudé <phi...@redhat.com> --- RFC because I'm not sure g_autoptr(GError) works this way.It does work. Any struct that's defined in GLib has support for g_autoptr(). If you aren't suyre though, just check for a G_DEFINE_AUTOPTR_CLEANUP_FUNC() macro usage that refers to the struct in question $ grep -r 'G_DEFINE_AUTOPTR_CLEANUP_FUNC(GError' /usr/include/glib-2.0 /usr/include/glib-2.0/glib/glib-autocleanups.h:G_DEFINE_AUTOPTR_CLEANUP_FUNC(GError, g_error_free)linux-user/syscall.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/linux-user/syscall.c b/linux-user/syscall.c index 8d27d10807..0e44969e16 100644 --- a/linux-user/syscall.c +++ b/linux-user/syscall.c @@ -7282,17 +7282,14 @@ static int do_openat(void *cpu_env, int dirfd, const char *pathname, int flags, } if (fake_open->filename) { - const char *tmpdir; - char filename[PATH_MAX]; + g_autoptr(GError) gerr = NULL; + g_autofree gchar *filename = NULL; int fd, r; /* create temporary file to map stat to */ - tmpdir = getenv("TMPDIR"); - if (!tmpdir) - tmpdir = "/tmp"; - snprintf(filename, sizeof(filename), "%s/qemu-open.XXXXXX", tmpdir); - fd = mkstemp(filename); + fd = g_file_open_tmp("qemu-open.XXXXXX", &filename, &gerr);g_file_open_tmp, calls g_get_tmp_name, which calls g_get_tmp_dir, which defaults to $TMPDIR, falling back to /tmp. So we're using the same dir as before.if (fd < 0) { + fprintf(stderr, "Error opening %s: %s\n", filename, gerr->message);This is wrong - the returned "filename" is only valid when g_file_open_tmp succeeds. So the use of "filename" here is likely a NULL. Given that the only place you use "filename" is in the error path, and that's not valid, we can simply eliminate it entirely, and pass NULL into g_file_open_tmp
'filename' is used right below to unlink it. But it can be dropped from the error message here since it's included in the error reported by GLib. Jano
return fd; } unlink(filename);Regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
signature.asc
Description: PGP signature
