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| author | Markus Armbruster <armbru@redhat.com> | 2024-02-03 09:02:25 +0100 |
|---|---|---|
| committer | Markus Armbruster <armbru@redhat.com> | 2024-02-14 07:44:38 +0100 |
| commit | a58c439a2d2c07ec05429d8774d75faeef4eac1e (patch) | |
| tree | 38398350bc3e1c28027f093d4879d91927754d40 /chardev | |
| parent | 5d1fc614413b10dd94858b07a1b2e26b1aa0296c (diff) | |
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 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 <armbru@redhat.com>
Message-ID: <20240203080228.2766159-2-armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
[Test fixed up for BSDs, indentation fixed up, commit message improved]
Diffstat (limited to 'chardev')
| -rw-r--r-- | chardev/char-parallel.c | 7 | ||||
| -rw-r--r-- | chardev/meson.build | 4 |
2 files changed, 6 insertions, 5 deletions
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({}) |