From a58c439a2d2c07ec05429d8774d75faeef4eac1e Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Sat, 3 Feb 2024 09:02:25 +0100 Subject: chardev/parallel: Don't close stdin on inappropriate device MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 new unit 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(). The next commit will fix char_hotswap_test()'s test for success. Signed-off-by: Markus Armbruster Message-ID: <20240203080228.2766159-2-armbru@redhat.com> Reviewed-by: Marc-André Lureau Reviewed-by: Eric Blake [Test fixed up for BSDs, indentation fixed up, commit message improved] --- chardev/char-parallel.c | 7 +++++-- chardev/meson.build | 4 +--- 2 files changed, 6 insertions(+), 5 deletions(-) (limited to 'chardev') diff --git a/chardev/char-parallel.c b/chardev/char-parallel.c index a5164f975a..78697d7522 100644 --- a/chardev/char-parallel.c +++ b/chardev/char-parallel.c @@ -164,13 +164,13 @@ static void qemu_chr_open_pp_fd(Chardev *chr, { ParallelChardev *drv = PARALLEL_CHARDEV(chr); + drv->fd = fd; + if (ioctl(fd, PPCLAIM) < 0) { error_setg_errno(errp, errno, "not a parallel port"); - close(fd); return; } - drv->fd = fd; drv->mode = IEEE1284_MODE_COMPAT; } #endif /* __linux__ */ @@ -238,6 +238,7 @@ static void qemu_chr_open_pp_fd(Chardev *chr, } #endif +#ifdef HAVE_CHARDEV_PARALLEL static void qmp_chardev_open_parallel(Chardev *chr, ChardevBackend *backend, bool *be_opened, @@ -306,3 +307,5 @@ static void register_types(void) } type_init(register_types); + +#endif /* HAVE_CHARDEV_PARALLEL */ diff --git a/chardev/meson.build b/chardev/meson.build index c80337d15f..70070a8279 100644 --- a/chardev/meson.build +++ 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', ), util) - if host_os in ['linux', 'gnu/kfreebsd', 'freebsd', 'dragonfly'] - chardev_ss.add(files('char-parallel.c')) - endif endif chardev_ss = chardev_ss.apply({}) -- cgit v1.2.3