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
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* Copyright IBM Corp. 2012
* Author(s): Jan Glauber <jang@linux.vnet.ibm.com>
*/
#include <linux/kernel.h>
#include <linux/syscalls.h>
#include <linux/signal.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/kernel_stat.h>
#include <asm/runtime_instr.h>
#include <asm/cpu_mf.h>
#include <asm/irq.h>
/* empty control block to disable RI by loading it */
struct runtime_instr_cb runtime_instr_empty_cb;
static int runtime_instr_avail(void)
{
return test_facility(64);
}
static void disable_runtime_instr(void)
{
struct pt_regs *regs = task_pt_regs(current);
load_runtime_instr_cb(&runtime_instr_empty_cb);
/*
* Make sure the RI bit is deleted from the PSW. If the user did not
* switch off RI before the system call the process will get a
* specification exception otherwise.
*/
regs->psw.mask &= ~PSW_MASK_RI;
}
static void init_runtime_instr_cb(struct runtime_instr_cb *cb)
{
cb->buf_limit = 0xfff;
if (s390_user_mode == HOME_SPACE_MODE)
cb->home_space = 1;
cb->int_requested = 1;
cb->pstate = 1;
cb->pstate_set_buf = 1;
cb->pstate_sample = 1;
cb->pstate_collect = 1;
cb->key = PAGE_DEFAULT_KEY;
cb->valid = 1;
}
void exit_thread_runtime_instr(void)
{
struct task_struct *task = current;
if (!task->thread.ri_cb)
return;
disable_runtime_instr();
kfree(task->thread.ri_cb);
task->thread.ri_signum = 0;
task->thread.ri_cb = NULL;
}
static void runtime_instr_int_handler(struct ext_code ext_code,
unsigned int param32, unsigned long param64)
{
struct siginfo info;
if (!(param32 & CPU_MF_INT_RI_MASK))
return;
inc_irq_stat(IRQEXT_CMR);
if (!current->thread.ri_cb)
return;
if (current->thread.ri_signum < SIGRTMIN ||
current->thread.ri_signum > SIGRTMAX) {
WARN_ON_ONCE(1);
return;
}
memset(&info, 0, sizeof(info));
info.si_signo = current->thread.ri_signum;
info.si_code = SI_QUEUE;
if (param32 & CPU_MF_INT_RI_BUF_FULL)
info.si_int = ENOBUFS;
else if (param32 & CPU_MF_INT_RI_HALTED)
info.si_int = ECANCELED;
else
return; /* unknown reason */
send_sig_info(current->thread.ri_signum, &info, current);
}
SYSCALL_DEFINE2(s390_runtime_instr, int, command, int, signum)
{
struct runtime_instr_cb *cb;
if (!runtime_instr_avail())
return -EOPNOTSUPP;
if (command == S390_RUNTIME_INSTR_STOP) {
preempt_disable();
exit_thread_runtime_instr();
preempt_enable();
return 0;
}
if (command != S390_RUNTIME_INSTR_START ||
(signum < SIGRTMIN || signum > SIGRTMAX))
return -EINVAL;
if (!current->thread.ri_cb) {
cb = kzalloc(sizeof(*cb), GFP_KERNEL);
if (!cb)
return -ENOMEM;
} else {
cb = current->thread.ri_cb;
memset(cb, 0, sizeof(*cb));
}
init_runtime_instr_cb(cb);
current->thread.ri_signum = signum;
/* now load the control block to make it available */
preempt_disable();
current->thread.ri_cb = cb;
load_runtime_instr_cb(cb);
preempt_enable();
return 0;
}
static int __init runtime_instr_init(void)
{
int rc;
if (!runtime_instr_avail())
return 0;
measurement_alert_subclass_register();
rc = register_external_interrupt(0x1407, runtime_instr_int_handler);
if (rc)
measurement_alert_subclass_unregister();
else
pr_info("Runtime instrumentation facility initialized\n");
return rc;
}
device_initcall(runtime_instr_init);
|
