diff options
2 files changed, 181 insertions, 2 deletions
diff --git a/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa/0004-Fixed-the-SIGSEGV-at-PCM-close.patch b/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa/0004-Fixed-the-SIGSEGV-at-PCM-close.patch new file mode 100644 index 00000000..52dbf773 --- /dev/null +++ b/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa/0004-Fixed-the-SIGSEGV-at-PCM-close.patch @@ -0,0 +1,180 @@ +From 23a1f554565c0cb9fade1a8f86ab9a09bf3d04e7 Mon Sep 17 00:00:00 2001 +From: Thierry Bultel <thierry.bultel@iot.bzh> +Date: Wed, 26 Dec 2018 10:06:38 +0100 +Subject: [PATCH] Fixed the SIGSEGV at PCM close + +There is a (still not identified) race condition at PCM +close, producing a SIGSEGV when pthread_cancel is called. +Instead of proposing a trick with pthread_setcancelstate, +this fix introduces a cancellation pipe, on which the io_thread +polls. This guaranties a better, safer, exit path. + +Signed-off-by: Thierry Bultel <thierry.bultel@iot.bzh> +--- + src/asound/bluealsa-pcm.c | 82 +++++++++++++++++++++++++++++++++++++++++------ + 1 file changed, 72 insertions(+), 10 deletions(-) + +diff --git a/src/asound/bluealsa-pcm.c b/src/asound/bluealsa-pcm.c +index 2136964..013aebb 100644 +--- a/src/asound/bluealsa-pcm.c ++++ b/src/asound/bluealsa-pcm.c +@@ -67,6 +67,8 @@ struct bluealsa_pcm { + snd_pcm_uframes_t io_hw_boundary; + snd_pcm_uframes_t io_hw_ptr; + ++ int cancelPipe[2]; ++ + }; + + +@@ -107,7 +109,9 @@ static void *io_thread(void *arg) { + struct asrsync asrs; + asrsync_init(&asrs, io->rate); + +- debug("Starting IO loop"); ++ const char * type = io->stream== SND_PCM_STREAM_CAPTURE?"CAPTURE":"PLAYBACK"; ++ ++ debug("------------ Starting IO loop (%s)-----------------------", type); + for (;;) { + + int tmp; +@@ -124,6 +128,11 @@ static void *io_thread(void *arg) { + debug("IO thread resumed: %d", io->state); + } + ++ if (pcm->io_started == false) { ++ debug("io_thread not started -> exit"); ++ goto final; ++ } ++ + snd_pcm_uframes_t io_ptr = pcm->io_ptr; + snd_pcm_uframes_t io_buffer_size = io->buffer_size; + snd_pcm_uframes_t io_hw_ptr = pcm->io_hw_ptr; +@@ -152,21 +161,44 @@ static void *io_thread(void *arg) { + if (io_hw_ptr >= io_hw_boundary) + io_hw_ptr -= io_hw_boundary; + ++ struct pollfd fds[2]; ++ ++ fds[0].fd = pcm->pcm_fd; ++ fds[1].fd = pcm->cancelPipe[0]; ++ ++ if (io->stream == SND_PCM_STREAM_CAPTURE) ++ fds[0].events |= POLLIN; ++ else ++ fds[0].events |= POLLOUT; ++ ++ fds[1].events = POLLIN | POLLHUP; ++ + if (io->stream == SND_PCM_STREAM_CAPTURE) { + + /* Read the whole period "atomically". This will assure, that frames + * are not fragmented, so the pointer can be correctly updated. */ +- while (len != 0 && (ret = read(pcm->pcm_fd, head, len)) != 0) { ++ while (len != 0 && ++ pcm->io_started) { ++ ++ int pollres = poll(fds, 2, -1); ++ ++ if ((fds[1].revents & POLLIN) != 0) { ++ debug("io_thread: CANCELLED"); ++ goto final; ++ } ++ ++ ret = read(pcm->pcm_fd, head, len); + if (ret == -1) { +- if (errno == EINTR) +- continue; ++ if (errno == EINTR) { ++ break; ++ } + SNDERR("PCM FIFO read error: %s", strerror(errno)); + goto final; + } + head += ret; + len -= ret; +- } + ++ } + if (ret == 0) + goto final; + +@@ -182,9 +214,18 @@ static void *io_thread(void *arg) { + + /* Perform atomic write - see the explanation above. */ + do { ++ ++ int pollres = poll(fds, 2, -1); ++ ++ if ((fds[1].revents & POLLIN) != 0) { ++ debug("io_thread: CANCELLED"); ++ goto final; ++ } ++ + if ((ret = write(pcm->pcm_fd, head, len)) == -1) { +- if (errno == EINTR) +- continue; ++ if (errno == EINTR) { ++ break; ++ } + SNDERR("PCM FIFO write error: %s", strerror(errno)); + goto final; + } +@@ -251,12 +292,24 @@ static int bluealsa_start(snd_pcm_ioplug_t *io) { + + static int bluealsa_stop(snd_pcm_ioplug_t *io) { + struct bluealsa_pcm *pcm = io->private_data; +- debug("Stopping"); ++ debug("Stopping %p", pcm); ++ if (!pcm) { ++ debug("PCM ALREADY CLOSED !"); ++ return 0; ++ } + if (pcm->io_started) { + pcm->io_started = false; +- pthread_cancel(pcm->io_thread); ++ ++ char dummy = 0; ++ ++ if (write(pcm->cancelPipe[1], &dummy, sizeof(dummy)) < 0) ++ debug("Failed to write to the cancellation pipe"); ++ + pthread_join(pcm->io_thread, NULL); + } ++done: ++ debug("Stop done"); ++ + return 0; + } + +@@ -269,10 +322,14 @@ static snd_pcm_sframes_t bluealsa_pointer(snd_pcm_ioplug_t *io) { + + static int bluealsa_close(snd_pcm_ioplug_t *io) { + struct bluealsa_pcm *pcm = io->private_data; +- debug("Closing plugin"); ++ debug("Closing plugin %p", pcm); + close(pcm->fd); + close(pcm->event_fd); ++ close(pcm->cancelPipe[0]); ++ close(pcm->cancelPipe[1]); + free(pcm); ++ io->private_data = NULL; ++ debug("PCM closed"); + return 0; + } + +@@ -649,6 +706,11 @@ SND_PCM_PLUGIN_DEFINE_FUNC(bluealsa) { + pcm->pcm_fd = -1; + pcm->delay_ex = delay; + ++ if (pipe(pcm->cancelPipe) == -1) { ++ SNDERR("BlueALSA failed to create cancellation pipe: %s", strerror(errno)); ++ ret = -errno; ++ } ++ + if ((pcm->fd = bluealsa_open(interface)) == -1) { + SNDERR("BlueALSA connection failed: %s", strerror(errno)); + ret = -errno; +-- +2.16.4 + diff --git a/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa_git.bbappend b/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa_git.bbappend index 43e4632f..8c67037f 100644 --- a/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa_git.bbappend +++ b/meta-audio-4a-framework/recipes-connectivity/bluez-alsa/bluez-alsa_git.bbappend @@ -7,5 +7,4 @@ FILESEXTRAPATHS_prepend := "${THISDIR}/${PN}:" SRC_URI += "file://0001-build-and-link-with-a-shared-library.patch" SRC_URI += "file://0002-log-add-calling-function-name.patch" SRC_URI += "file://0003-increased-the-number-of-connexions-to-16.patch" - - +SRC_URI += "file://0004-Fixed-the-SIGSEGV-at-PCM-close.patch" |