File 0016-pcm-direct-Protect-from-freeing-semaphore-... of Package alsa.5967

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File 0016-pcm-direct-Protect-from-freeing-semaphore-when-alrea.patch of Package alsa.5967

From 2dd78251ff0c4009b478574cca7aef2eb05c2279 Mon Sep 17 00:00:00 2001
From: Joshua Frkuska <joshua_frkuska@mentor.com>
Date: Fri, 25 Nov 2016 15:43:40 +0530
Subject: [PATCH] pcm: direct: Protect from freeing semaphore when already in
 use

In the case of dshare, dsnoop, and dmix when a device is opened twice
and fails the second time, the semaphore is completely discarded. This
creates dangling semaphore data.

This patch removes the possibility for the semaphore to be destroyed during
a typical open failure by first checking if the shared memory can be destroyed
or not. If the shared memory cannot be released it means both it and the
semaphore are still in use and therefore the semaphore is just released.

Signed-off-by: Joshua Frkuska <joshua_frkuska@mentor.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
---
 src/pcm/pcm_dmix.c   | 7 ++++---
 src/pcm/pcm_dshare.c | 7 ++++---
 src/pcm/pcm_dsnoop.c | 8 +++++---
 3 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/src/pcm/pcm_dmix.c b/src/pcm/pcm_dmix.c
index 2714fb93c758..2fedb1c14a3b 100644
--- a/src/pcm/pcm_dmix.c
+++ b/src/pcm/pcm_dmix.c
@@ -1154,9 +1154,10 @@ int snd_pcm_dmix_open(snd_pcm_t **pcmp, const char *name,
 		snd_pcm_close(spcm);
 	if (dmix->u.dmix.shmid_sum >= 0)
 		shm_sum_discard(dmix);
-	if (dmix->shmid >= 0)
-		snd_pcm_direct_shm_discard(dmix);
-	if (snd_pcm_direct_semaphore_discard(dmix) < 0)
+	if ((dmix->shmid >= 0) && (snd_pcm_direct_shm_discard(dmix))) {
+		if (snd_pcm_direct_semaphore_discard(dmix))
+			snd_pcm_direct_semaphore_final(dmix, DIRECT_IPC_SEM_CLIENT);
+	} else
 		snd_pcm_direct_semaphore_up(dmix, DIRECT_IPC_SEM_CLIENT);
  _err_nosem:
 	if (dmix) {
diff --git a/src/pcm/pcm_dshare.c b/src/pcm/pcm_dshare.c
index 9b478a714468..01f5eed8f97a 100644
--- a/src/pcm/pcm_dshare.c
+++ b/src/pcm/pcm_dshare.c
@@ -846,9 +846,10 @@ int snd_pcm_dshare_open(snd_pcm_t **pcmp, const char *name,
 		snd_pcm_direct_client_discard(dshare);
 	if (spcm)
 		snd_pcm_close(spcm);
-	if (dshare->shmid >= 0)
-		snd_pcm_direct_shm_discard(dshare);
-	if (snd_pcm_direct_semaphore_discard(dshare) < 0)
+	if ((dshare->shmid >= 0) && (snd_pcm_direct_shm_discard(dshare))) {
+		if (snd_pcm_direct_semaphore_discard(dshare))
+			snd_pcm_direct_semaphore_final(dshare, DIRECT_IPC_SEM_CLIENT);
+	} else
 		snd_pcm_direct_semaphore_up(dshare, DIRECT_IPC_SEM_CLIENT);
  _err_nosem:
 	if (dshare) {
diff --git a/src/pcm/pcm_dsnoop.c b/src/pcm/pcm_dsnoop.c
index 4efbc53d177e..1aedf3cb73d2 100644
--- a/src/pcm/pcm_dsnoop.c
+++ b/src/pcm/pcm_dsnoop.c
@@ -719,10 +719,12 @@ int snd_pcm_dsnoop_open(snd_pcm_t **pcmp, const char *name,
 		snd_pcm_direct_client_discard(dsnoop);
 	if (spcm)
 		snd_pcm_close(spcm);
-	if (dsnoop->shmid >= 0)
-		snd_pcm_direct_shm_discard(dsnoop);
-	if (snd_pcm_direct_semaphore_discard(dsnoop) < 0)
+	if ((dsnoop->shmid >= 0) && (snd_pcm_direct_shm_discard(dsnoop))) {
+		if (snd_pcm_direct_semaphore_discard(dsnoop))
+			snd_pcm_direct_semaphore_final(dsnoop, DIRECT_IPC_SEM_CLIENT);
+	} else
 		snd_pcm_direct_semaphore_up(dsnoop, DIRECT_IPC_SEM_CLIENT);
+
  _err_nosem:
 	if (dsnoop) {
 		free(dsnoop->bindings);
-- 
2.10.2

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