From: Mao Jinlong <quic_jinlmao@quicinc.com> To: Alexander Shishkin <alexander.shishkin@linux.intel.com>, Maxime Coquelin <mcoquelin.stm32@gmail.com>, Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Mao Jinlong <quic_jinlmao@quicinc.com>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-msm@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, Tingwei Zhang <quic_tingweiz@quicinc.com>, Yuanfang Zhang <quic_yuanfang@quicinc.com>, Tao Zhang <quic_taozha@quicinc.com>, Hao Zhang <quic_hazha@quicinc.com> Subject: [PATCH] stm class: Fix double add issue when store source_link Date: Mon, 18 Apr 2022 19:46:58 +0800 [thread overview] Message-ID: <20220418114658.6491-1-quic_jinlmao@quicinc.com> (raw) If two threads store the same stm device to stm_source_link at the same time when stm->link_list is empty, it is possible that stm_source_link_add will be called for both of these two threads. Then double add issue below will happen. Add mutex lock for stm_source_link drop and stm_source_link add to avoid this race condition. [ 12.386579][ T1024] list_add double add: new=ffffff87b73ebd90, prev=ffffff87b73ebd90, next=ffffffc012737700. [ 12.386657][ T1024] -----------[ cut here ]----------- [ 12.386671][ T1024] kernel BUG at lib/list_debug.c:31! [ 12.388845][ T1024] CPU: 2 PID: 1024 Comm: sh [ 12.389162][ T1024] Call trace: [ 12.389174][ T1024] __list_add_valid+0x68/0x98 [ 12.389199][ T1024] stm_source_link_store+0xcc/0x314 [stm_core] [ 12.389213][ T1024] dev_attr_store+0x38/0x8c [ 12.389228][ T1024] sysfs_kf_write+0xa0/0x100 [ 12.389239][ T1024] kernfs_fop_write_iter+0x1b0/0x2f8 [ 12.389253][ T1024] vfs_write+0x300/0x37c [ 12.389264][ T1024] ksys_write+0x84/0x12c Signed-off-by: Yuanfang Zhang <quic_yuanfang@quicinc.com> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> --- drivers/hwtracing/stm/core.c | 7 ++++++- drivers/hwtracing/stm/stm.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 2712e699ba08..e73ac961acb2 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -1171,11 +1171,14 @@ static ssize_t stm_source_link_store(struct device *dev, struct stm_device *link; int err; + mutex_lock(&src->link_mutex); stm_source_link_drop(src); link = stm_find_device(buf); - if (!link) + if (!link) { + mutex_lock(&src->link_mutex); return -EINVAL; + } pm_runtime_get(&link->dev); @@ -1185,6 +1188,7 @@ static ssize_t stm_source_link_store(struct device *dev, /* matches the stm_find_device() above */ stm_put_device(link); } + mutex_unlock(&src->link_mutex); return err ? : count; } @@ -1251,6 +1255,7 @@ int stm_source_register_device(struct device *parent, stm_output_init(&src->output); spin_lock_init(&src->link_lock); + mutex_init(&src->link_mutex); INIT_LIST_HEAD(&src->link_entry); src->data = data; data->src = src; diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h index a9be49fc7a6b..60b814cc00e0 100644 --- a/drivers/hwtracing/stm/stm.h +++ b/drivers/hwtracing/stm/stm.h @@ -79,6 +79,7 @@ void stm_put_device(struct stm_device *stm); struct stm_source_device { struct device dev; struct stm_source_data *data; + struct mutex link_mutex; spinlock_t link_lock; struct stm_device __rcu *link; struct list_head link_entry; -- 2.17.1
WARNING: multiple messages have this Message-ID (diff)
From: Mao Jinlong <quic_jinlmao@quicinc.com> To: Alexander Shishkin <alexander.shishkin@linux.intel.com>, Maxime Coquelin <mcoquelin.stm32@gmail.com>, Alexandre Torgue <alexandre.torgue@foss.st.com> Cc: Mao Jinlong <quic_jinlmao@quicinc.com>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-msm@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org>, Tingwei Zhang <quic_tingweiz@quicinc.com>, Yuanfang Zhang <quic_yuanfang@quicinc.com>, Tao Zhang <quic_taozha@quicinc.com>, Hao Zhang <quic_hazha@quicinc.com> Subject: [PATCH] stm class: Fix double add issue when store source_link Date: Mon, 18 Apr 2022 19:46:58 +0800 [thread overview] Message-ID: <20220418114658.6491-1-quic_jinlmao@quicinc.com> (raw) If two threads store the same stm device to stm_source_link at the same time when stm->link_list is empty, it is possible that stm_source_link_add will be called for both of these two threads. Then double add issue below will happen. Add mutex lock for stm_source_link drop and stm_source_link add to avoid this race condition. [ 12.386579][ T1024] list_add double add: new=ffffff87b73ebd90, prev=ffffff87b73ebd90, next=ffffffc012737700. [ 12.386657][ T1024] -----------[ cut here ]----------- [ 12.386671][ T1024] kernel BUG at lib/list_debug.c:31! [ 12.388845][ T1024] CPU: 2 PID: 1024 Comm: sh [ 12.389162][ T1024] Call trace: [ 12.389174][ T1024] __list_add_valid+0x68/0x98 [ 12.389199][ T1024] stm_source_link_store+0xcc/0x314 [stm_core] [ 12.389213][ T1024] dev_attr_store+0x38/0x8c [ 12.389228][ T1024] sysfs_kf_write+0xa0/0x100 [ 12.389239][ T1024] kernfs_fop_write_iter+0x1b0/0x2f8 [ 12.389253][ T1024] vfs_write+0x300/0x37c [ 12.389264][ T1024] ksys_write+0x84/0x12c Signed-off-by: Yuanfang Zhang <quic_yuanfang@quicinc.com> Signed-off-by: Mao Jinlong <quic_jinlmao@quicinc.com> --- drivers/hwtracing/stm/core.c | 7 ++++++- drivers/hwtracing/stm/stm.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) diff --git a/drivers/hwtracing/stm/core.c b/drivers/hwtracing/stm/core.c index 2712e699ba08..e73ac961acb2 100644 --- a/drivers/hwtracing/stm/core.c +++ b/drivers/hwtracing/stm/core.c @@ -1171,11 +1171,14 @@ static ssize_t stm_source_link_store(struct device *dev, struct stm_device *link; int err; + mutex_lock(&src->link_mutex); stm_source_link_drop(src); link = stm_find_device(buf); - if (!link) + if (!link) { + mutex_lock(&src->link_mutex); return -EINVAL; + } pm_runtime_get(&link->dev); @@ -1185,6 +1188,7 @@ static ssize_t stm_source_link_store(struct device *dev, /* matches the stm_find_device() above */ stm_put_device(link); } + mutex_unlock(&src->link_mutex); return err ? : count; } @@ -1251,6 +1255,7 @@ int stm_source_register_device(struct device *parent, stm_output_init(&src->output); spin_lock_init(&src->link_lock); + mutex_init(&src->link_mutex); INIT_LIST_HEAD(&src->link_entry); src->data = data; data->src = src; diff --git a/drivers/hwtracing/stm/stm.h b/drivers/hwtracing/stm/stm.h index a9be49fc7a6b..60b814cc00e0 100644 --- a/drivers/hwtracing/stm/stm.h +++ b/drivers/hwtracing/stm/stm.h @@ -79,6 +79,7 @@ void stm_put_device(struct stm_device *stm); struct stm_source_device { struct device dev; struct stm_source_data *data; + struct mutex link_mutex; spinlock_t link_lock; struct stm_device __rcu *link; struct list_head link_entry; -- 2.17.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next reply other threads:[~2022-04-18 11:47 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-18 11:46 Mao Jinlong [this message] 2022-04-18 11:46 ` [PATCH] stm class: Fix double add issue when store source_link Mao Jinlong 2022-05-16 7:14 ` Jinlong Mao 2022-05-16 7:14 ` Jinlong Mao 2022-11-02 9:34 ` Jinlong Mao 2022-11-02 9:34 ` Jinlong Mao
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