blob: 2f39f3e0ed31eda081f34fa078b2e3bd833db5d7 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
|
From bde5632fe56cf6aaaec61f7b0192449f585fca6e Mon Sep 17 00:00:00 2001
From: Felix Kuehling <Felix.Kuehling@amd.com>
Date: Tue, 26 Jul 2016 17:22:46 -0400
Subject: [PATCH 1162/4131] drm/amdkfd: Get reference to lead_thread task
struct
Increment the kfd_process.lead_thread's reference counter to make
it safe to dereference. This will be needed for getting a safe
reference to the process' mm_struct.
Change-Id: I2a38f5f2de989dd4f19115d21d31ea6df953806c
Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
---
drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 2 ++
drivers/gpu/drm/amd/amdkfd/kfd_process.c | 3 +++
2 files changed, 5 insertions(+)
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
index 1a9aab7..054a784 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h
@@ -618,6 +618,8 @@ struct kfd_process {
* In any process, the thread that started main() is the lead
* thread and outlives the rest.
* It is here because amd_iommu_bind_pasid wants a task_struct.
+ * It can also be used for safely getting a reference to the
+ * mm_struct of the process.
*/
struct task_struct *lead_thread;
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process.c b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
index ec066d8..889d165 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process.c
@@ -466,6 +466,8 @@ static void kfd_process_ref_release(struct kref *ref)
kfd_pasid_free(p->pasid);
+ put_task_struct(p->lead_thread);
+
kfree(p);
}
@@ -647,6 +649,7 @@ static struct kfd_process *create_process(const struct task_struct *thread)
(uintptr_t)process->mm);
process->lead_thread = thread->group_leader;
+ get_task_struct(process->lead_thread);
INIT_LIST_HEAD(&process->per_device_data);
--
2.7.4
|
