Re: [PATCH 1/4] chardev/parallel: Don't close stdin on inappropriate device

The __linux__ version of qemu_chr_open_pp_fd() tries to claim the parport device with a PPCLAIM ioctl(). On success, it stores the file descriptor in the chardev object, and returns success. On failure, it closes the file descriptor, and returns failure. chardev_new() then passes the Chardev to object_unref(). This duly calls char_parallel_finalize(), which closes the file descriptor stored in the chardev object. Since qemu_chr_open_pp_fd() didn't store it, it's still zero, so this closes standard input. Ooopsie. To demonstate, add a unit test. With the bug above unfixed, running this test closes standard input. char_hotswap_test() happens to run next. It opens a socket, duly gets file descriptor 0, and since it tests for success with > 0 instead of >= 0, it fails.

The test needs to be conditional exactly like the chardev it tests. Since the condition is rather complicated, steal the solution from the serial chardev: define HAVE_CHARDEV_PARALLEL in qemu/osdep.h. This also permits simplifying chardev/meson.build a bit. The bug fix is easy enough: store the file descriptor, and leave closing it to char_parallel_finalize(). Signed-off-by: Markus Armbruster <armbru(a)redhat.com&gt; ---

+++ b/include/qemu/osdep.h @@ -508,11 +508,18 @@ void qemu_anon_ram_free(void *ptr, size_t size); #ifdef _WIN32 #define HAVE_CHARDEV_SERIAL 1 -#elif defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ +#define HAVE_CHARDEV_PARALLEL 1 +#else +#if defined(__linux__) || defined(__sun__) || defined(__FreeBSD__) \ || defined(__NetBSD__) || defined(__OpenBSD__) || defined(__DragonFly__) \ || defined(__GLIBC__) || defined(__APPLE__) #define HAVE_CHARDEV_SERIAL 1 #endif +#if defined(__linux__) || defined(__FreeBSD__) \ + || defined(__FreeBSD_kernel__) || defined(__DragonFly__) +#define HAVE_CHARDEV_PARALLEL 1 +#endif +#endif

+++ b/chardev/meson.build @@ -21,11 +21,9 @@ if host_os == 'windows' else chardev_ss.add(files( 'char-fd.c', + 'char-parallel.c', 'char-pty.c',