[alsa-devel] [PATCH alsa-lib 1/3] Open device nodes with close-on-exec flag
From: Rémi Denis-Courmont remi@remlab.net
This avoid leaking device descriptors through exec. Thus ALSA applications can safely spawn other processes in their background.
Signed-off-by: Rémi Denis-Courmont remi@remlab.net --- include/local.h | 23 +++++++++++++++++------ 1 files changed, 17 insertions(+), 6 deletions(-)
diff --git a/include/local.h b/include/local.h index b5a1c45..5b54def 100644 --- a/include/local.h +++ b/include/local.h @@ -230,22 +230,33 @@ extern snd_lib_error_handler_t snd_err_msg; # define link_warning(symbol, msg) #endif
-/* open with resmgr */ -#ifdef SUPPORT_RESMGR static inline int snd_open_device(const char *filename, int fmode) { - int fd = open(filename, fmode); + int fd; + +#ifdef O_CLOEXEC + fd = open(filename, fmode|O_CLOEXEC); if (fd >= 0) return fd; + if (errno == EINVAL) +#endif + { + fd = open(filename, fmode); + if (fd >= 0) { + fcntl(fd, F_SETFD, FD_CLOEXEC); + return fd; + } + } + +/* open with resmgr */ +#ifdef SUPPORT_RESMGR if (errno == EAGAIN || errno == EBUSY) return fd; if (! access(filename, F_OK)) return rsm_open_device(filename, fmode); +#endif return -1; } -#else -#define snd_open_device(filename, fmode) open(filename, fmode); -#endif
/* make local functions really local */ #define snd_dlobj_cache_lookup \
From: Rémi Denis-Courmont remi@remlab.net
Signed-off-by: Rémi Denis-Courmont remi@remlab.net --- src/control/control_hw.c | 11 ----------- src/hwdep/hwdep_hw.c | 11 ----------- src/pcm/pcm_hw.c | 12 ------------ src/rawmidi/rawmidi_hw.c | 11 ----------- src/seq/seq_hw.c | 11 ----------- src/timer/timer_hw.c | 11 ----------- 6 files changed, 0 insertions(+), 67 deletions(-)
diff --git a/src/control/control_hw.c b/src/control/control_hw.c index e9a6be2..cf258b4 100644 --- a/src/control/control_hw.c +++ b/src/control/control_hw.c @@ -392,17 +392,6 @@ int snd_ctl_hw_open(snd_ctl_t **handle, const char *name, int card, int mode) if (fd < 0) return -errno; } -#if 0 - /* - * this is bogus, an application have to care about open filedescriptors - */ - if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) { - SYSERR("fcntl FD_CLOEXEC failed"); - err = -errno; - close(fd); - return err; - } -#endif if (ioctl(fd, SNDRV_CTL_IOCTL_PVERSION, &ver) < 0) { err = -errno; close(fd); diff --git a/src/hwdep/hwdep_hw.c b/src/hwdep/hwdep_hw.c index 238a507..e4fcdc3 100644 --- a/src/hwdep/hwdep_hw.c +++ b/src/hwdep/hwdep_hw.c @@ -122,17 +122,6 @@ int snd_hwdep_hw_open(snd_hwdep_t **handle, const char *name, int card, int devi if (fd < 0) return -errno; } -#if 0 - /* - * this is bogus, an application have to care about open filedescriptors - */ - if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) { - SYSERR("fcntl FD_CLOEXEC failed"); - ret = -errno; - close(fd); - return ret; - } -#endif if (ioctl(fd, SNDRV_HWDEP_IOCTL_PVERSION, &ver) < 0) { ret = -errno; close(fd); diff --git a/src/pcm/pcm_hw.c b/src/pcm/pcm_hw.c index 8abb204..2095b01 100644 --- a/src/pcm/pcm_hw.c +++ b/src/pcm/pcm_hw.c @@ -1144,18 +1144,6 @@ int snd_pcm_hw_open_fd(snd_pcm_t **pcmp, const char *name, if (fmode & O_ASYNC) mode |= SND_PCM_ASYNC;
-#if 0 - /* - * this is bogus, an application have to care about open filedescriptors - */ - if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) { - ret = -errno; - SYSMSG("fcntl FD_CLOEXEC failed"); - close(fd); - return ret; - } -#endif - if (ioctl(fd, SNDRV_PCM_IOCTL_PVERSION, &ver) < 0) { ret = -errno; SYSMSG("SNDRV_PCM_IOCTL_PVERSION failed"); diff --git a/src/rawmidi/rawmidi_hw.c b/src/rawmidi/rawmidi_hw.c index 87829fd..e08dca7 100644 --- a/src/rawmidi/rawmidi_hw.c +++ b/src/rawmidi/rawmidi_hw.c @@ -234,17 +234,6 @@ int snd_rawmidi_hw_open(snd_rawmidi_t **inputp, snd_rawmidi_t **outputp, return -errno; } } -#if 0 - /* - * this is bogus, an application have to care about open filedescriptors - */ - if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) { - SYSERR("fcntl FD_CLOEXEC failed"); - ret = -errno; - close(fd); - return ret; - } -#endif if (ioctl(fd, SNDRV_RAWMIDI_IOCTL_PVERSION, &ver) < 0) { ret = -errno; SYSERR("SNDRV_RAWMIDI_IOCTL_PVERSION failed"); diff --git a/src/seq/seq_hw.c b/src/seq/seq_hw.c index 0e94593..5bb26f3 100644 --- a/src/seq/seq_hw.c +++ b/src/seq/seq_hw.c @@ -457,17 +457,6 @@ int snd_seq_hw_open(snd_seq_t **handle, const char *name, int streams, int mode) SYSERR("open %s failed", filename); return -errno; } -#if 0 - /* - * this is bogus, an application have to care about open filedescriptors - */ - if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) { - SYSERR("fcntl FD_CLOEXEC failed"); - ret = -errno; - close(fd); - return ret; - } -#endif if (ioctl(fd, SNDRV_SEQ_IOCTL_PVERSION, &ver) < 0) { SYSERR("SNDRV_SEQ_IOCTL_PVERSION failed"); ret = -errno; diff --git a/src/timer/timer_hw.c b/src/timer/timer_hw.c index 3453858..25f3bab 100644 --- a/src/timer/timer_hw.c +++ b/src/timer/timer_hw.c @@ -236,17 +236,6 @@ int snd_timer_hw_open(snd_timer_t **handle, const char *name, int dev_class, int fd = snd_open_device(SNDRV_FILE_TIMER, tmode); if (fd < 0) return -errno; -#if 0 - /* - * this is bogus, an application have to care about open filedescriptors - */ - if (fcntl(fd, F_SETFD, FD_CLOEXEC) != 0) { - SYSERR("fcntl FD_CLOEXEC failed"); - ret = -errno; - close(fd); - return ret; - } -#endif if (ioctl(fd, SNDRV_TIMER_IOCTL_PVERSION, &ver) < 0) { ret = -errno; close(fd);
From: Rémi Denis-Courmont remi@remlab.net
This enables thread-safe close-on-exec file descriptor flag setting if the underlying kernel supports it.
Signed-off-by: Rémi Denis-Courmont remi@remlab.net --- configure.in | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-)
diff --git a/configure.in b/configure.in index a455de1..cc8950f 100644 --- a/configure.in +++ b/configure.in @@ -38,6 +38,8 @@ then AC_MSG_RESULT($CC) fi +CFLAGS="$CFLAGS -D_GNU_SOURCE" +
AC_PROG_CC AC_PROG_CPP
participants (1)
-
Rémi Denis-Courmont