Commit | Line | Data |
---|---|---|
b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
916cda1a MS |
2 | /* |
3 | * Copyright IBM Corp. 2016 | |
4 | * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> | |
5 | */ | |
6 | ||
7 | #include <linux/kernel.h> | |
8 | #include <linux/syscalls.h> | |
9 | #include <linux/signal.h> | |
10 | #include <linux/mm.h> | |
11 | #include <linux/slab.h> | |
12 | #include <asm/guarded_storage.h> | |
13 | #include "entry.h" | |
14 | ||
7b83c629 | 15 | void guarded_storage_release(struct task_struct *tsk) |
916cda1a | 16 | { |
7b83c629 HC |
17 | kfree(tsk->thread.gs_cb); |
18 | kfree(tsk->thread.gs_bc_cb); | |
916cda1a MS |
19 | } |
20 | ||
21 | static int gs_enable(void) | |
22 | { | |
23 | struct gs_cb *gs_cb; | |
24 | ||
25 | if (!current->thread.gs_cb) { | |
26 | gs_cb = kzalloc(sizeof(*gs_cb), GFP_KERNEL); | |
27 | if (!gs_cb) | |
28 | return -ENOMEM; | |
29 | gs_cb->gsd = 25; | |
30 | preempt_disable(); | |
99441a38 | 31 | local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT); |
916cda1a MS |
32 | load_gs_cb(gs_cb); |
33 | current->thread.gs_cb = gs_cb; | |
34 | preempt_enable(); | |
35 | } | |
36 | return 0; | |
37 | } | |
38 | ||
39 | static int gs_disable(void) | |
40 | { | |
41 | if (current->thread.gs_cb) { | |
42 | preempt_disable(); | |
43 | kfree(current->thread.gs_cb); | |
44 | current->thread.gs_cb = NULL; | |
99441a38 | 45 | local_ctl_clear_bit(2, CR2_GUARDED_STORAGE_BIT); |
916cda1a MS |
46 | preempt_enable(); |
47 | } | |
48 | return 0; | |
49 | } | |
50 | ||
51 | static int gs_set_bc_cb(struct gs_cb __user *u_gs_cb) | |
52 | { | |
53 | struct gs_cb *gs_cb; | |
54 | ||
55 | gs_cb = current->thread.gs_bc_cb; | |
56 | if (!gs_cb) { | |
57 | gs_cb = kzalloc(sizeof(*gs_cb), GFP_KERNEL); | |
58 | if (!gs_cb) | |
59 | return -ENOMEM; | |
60 | current->thread.gs_bc_cb = gs_cb; | |
61 | } | |
62 | if (copy_from_user(gs_cb, u_gs_cb, sizeof(*gs_cb))) | |
63 | return -EFAULT; | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static int gs_clear_bc_cb(void) | |
68 | { | |
69 | struct gs_cb *gs_cb; | |
70 | ||
71 | gs_cb = current->thread.gs_bc_cb; | |
72 | current->thread.gs_bc_cb = NULL; | |
73 | kfree(gs_cb); | |
74 | return 0; | |
75 | } | |
76 | ||
77 | void gs_load_bc_cb(struct pt_regs *regs) | |
78 | { | |
79 | struct gs_cb *gs_cb; | |
80 | ||
81 | preempt_disable(); | |
82 | clear_thread_flag(TIF_GUARDED_STORAGE); | |
83 | gs_cb = current->thread.gs_bc_cb; | |
84 | if (gs_cb) { | |
85 | kfree(current->thread.gs_cb); | |
86 | current->thread.gs_bc_cb = NULL; | |
99441a38 | 87 | local_ctl_set_bit(2, CR2_GUARDED_STORAGE_BIT); |
916cda1a MS |
88 | load_gs_cb(gs_cb); |
89 | current->thread.gs_cb = gs_cb; | |
90 | } | |
91 | preempt_enable(); | |
92 | } | |
93 | ||
94 | static int gs_broadcast(void) | |
95 | { | |
96 | struct task_struct *sibling; | |
97 | ||
98 | read_lock(&tasklist_lock); | |
99 | for_each_thread(current, sibling) { | |
100 | if (!sibling->thread.gs_bc_cb) | |
101 | continue; | |
102 | if (test_and_set_tsk_thread_flag(sibling, TIF_GUARDED_STORAGE)) | |
103 | kick_process(sibling); | |
104 | } | |
105 | read_unlock(&tasklist_lock); | |
106 | return 0; | |
107 | } | |
108 | ||
109 | SYSCALL_DEFINE2(s390_guarded_storage, int, command, | |
110 | struct gs_cb __user *, gs_cb) | |
111 | { | |
112 | if (!MACHINE_HAS_GS) | |
113 | return -EOPNOTSUPP; | |
114 | switch (command) { | |
115 | case GS_ENABLE: | |
116 | return gs_enable(); | |
117 | case GS_DISABLE: | |
118 | return gs_disable(); | |
119 | case GS_SET_BC_CB: | |
120 | return gs_set_bc_cb(gs_cb); | |
121 | case GS_CLEAR_BC_CB: | |
122 | return gs_clear_bc_cb(); | |
123 | case GS_BROADCAST: | |
124 | return gs_broadcast(); | |
125 | default: | |
126 | return -EINVAL; | |
127 | } | |
128 | } |