4.19-stable review patch. If anyone has any objections, please let me know.
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[ Upstream commit 482f96324a4e08818db7d75bb12beaaea6c9561d ]
The current recovery code gets a pointer to the task struct and does a few things all within the rcu_read_lock. This puts constraints on the types of gfp flags that can be used within the rcu lock. This patch instead gets a reference to the task within the rcu lock and releases the lock immediately, this way the task stays afloat until we need it and we also get to use the desired gfp flags.
Signed-off-by: Sharat Masetty smasetty@codeaurora.org Signed-off-by: Rob Clark robdclark@gmail.com Signed-off-by: Sean Paul seanpaul@chromium.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/msm/msm_gpu.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c index 46e6b82f7b66..52a2146dc1f2 100644 --- a/drivers/gpu/drm/msm/msm_gpu.c +++ b/drivers/gpu/drm/msm/msm_gpu.c @@ -425,10 +425,9 @@ static void recover_worker(struct work_struct *work) if (submit) { struct task_struct *task;
- rcu_read_lock(); - task = pid_task(submit->pid, PIDTYPE_PID); + task = get_pid_task(submit->pid, PIDTYPE_PID); if (task) { - comm = kstrdup(task->comm, GFP_ATOMIC); + comm = kstrdup(task->comm, GFP_KERNEL);
/* * So slightly annoying, in other paths like @@ -441,10 +440,10 @@ static void recover_worker(struct work_struct *work) * about the submit going away. */ mutex_unlock(&dev->struct_mutex); - cmd = kstrdup_quotable_cmdline(task, GFP_ATOMIC); + cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL); + put_task_struct(task); mutex_lock(&dev->struct_mutex); } - rcu_read_unlock();
if (comm && cmd) { dev_err(dev->dev, "%s: offending task: %s (%s)\n",