-
Notifications
You must be signed in to change notification settings - Fork 580
/
VirtualPerfCounterMonitor.cc
171 lines (150 loc) · 4.95 KB
/
VirtualPerfCounterMonitor.cc
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/* -*- Mode: C++; tab-width: 8; c-basic-offset: 2; indent-tabs-mode: nil; -*- */
#include "VirtualPerfCounterMonitor.h"
#include <linux/perf_event.h>
#include <stdlib.h>
#include "AutoRemoteSyscalls.h"
#include "RecordSession.h"
#include "RecordTask.h"
#include "log.h"
using namespace std;
namespace rr {
std::map<TaskUid, VirtualPerfCounterMonitor*>
VirtualPerfCounterMonitor::tasks_with_interrupts =
std::map<TaskUid, VirtualPerfCounterMonitor*>();
bool VirtualPerfCounterMonitor::should_virtualize(
const struct perf_event_attr& attr) {
return PerfCounters::is_rr_ticks_attr(attr);
}
VirtualPerfCounterMonitor::VirtualPerfCounterMonitor(
Task* t, Task* target, const struct perf_event_attr& attr)
: initial_ticks(target->tick_count()),
target_tuid_(target->tuid()),
owner_tid(0),
flags(0),
sig(0),
enabled(false) {
ASSERT(t, should_virtualize(attr));
if (t->session().is_recording()) {
maybe_enable_interrupt(t, attr.sample_period);
}
}
VirtualPerfCounterMonitor::~VirtualPerfCounterMonitor() { disable_interrupt(); }
bool VirtualPerfCounterMonitor::emulate_ioctl(RecordTask* t, uint64_t* result) {
switch ((int)t->regs().arg2()) {
case PERF_EVENT_IOC_ENABLE:
*result = 0;
enabled = true;
break;
case PERF_EVENT_IOC_DISABLE:
*result = 0;
enabled = false;
break;
case PERF_EVENT_IOC_RESET: {
*result = 0;
RecordTask* target = t->session().find_task(target_tuid());
initial_ticks = target->tick_count();
break;
}
case PERF_EVENT_IOC_PERIOD: {
*result = 0;
maybe_enable_interrupt(
t, t->read_mem(remote_ptr<uint64_t>(t->regs().arg3())));
break;
}
default:
ASSERT(t, false) << "Unsupported perf event ioctl "
<< HEX((int)t->regs().arg2());
break;
}
return true;
}
bool VirtualPerfCounterMonitor::emulate_fcntl(RecordTask* t, uint64_t* result) {
*result = -(int64_t)EINVAL;
switch ((int)t->regs().arg2()) {
case F_SETOWN_EX: {
auto owner = t->read_mem(remote_ptr<struct f_owner_ex>(t->regs().arg3()));
ASSERT(t, owner.type == F_OWNER_TID)
<< "Unsupported perf event F_SETOWN_EX type " << owner.type;
ASSERT(t, owner.pid == target_tuid().tid())
<< "Perf event F_SETOWN_EX is only supported to the target tid";
owner_tid = owner.pid;
*result = 0;
break;
}
case F_SETFL:
ASSERT(t, !(t->regs().arg3() & ~O_ASYNC))
<< "Unsupported perf event flags " << HEX((int)t->regs().arg3());
flags = (int)t->regs().arg3();
*result = 0;
break;
case F_SETSIG:
sig = (int)t->regs().arg3();
*result = 0;
break;
default:
ASSERT(t, false) << "Unsupported perf event fnctl "
<< HEX((int)t->regs().arg2());
break;
}
return true;
}
bool VirtualPerfCounterMonitor::emulate_read(RecordTask* t,
const vector<Range>& ranges,
LazyOffset&, uint64_t* result) {
RecordTask* target = t->session().find_task(target_tuid());
if (target) {
int64_t val;
val = target->tick_count() - initial_ticks;
*result = t->write_ranges(ranges, &val, sizeof(val));
} else {
*result = 0;
}
return true;
}
void VirtualPerfCounterMonitor::maybe_enable_interrupt(Task* t,
uint64_t after) {
Task* target = t->session().find_task(target_tuid());
if (after == 0 || after > 0xffffffff) {
return;
}
auto previous =
tasks_with_interrupts.insert(std::make_pair(target_tuid(), this));
ASSERT(t, previous.second || previous.first->second == this)
<< "Multiple virtualized performance counters with interrupts\n\tFirst "
"at "
<< previous.first->second << "\tSecond at " << this;
target_ticks_ = target->tick_count() + after;
}
void VirtualPerfCounterMonitor::disable_interrupt() const {
auto found = tasks_with_interrupts.find(target_tuid());
if (found == tasks_with_interrupts.end()) {
return;
}
if (found->second == this) {
tasks_with_interrupts.erase(found);
}
}
void VirtualPerfCounterMonitor::synthesize_signal(RecordTask* t) const {
// Use NativeArch here because different versions of system headers
// have inconsistent field naming.
union {
NativeArch::siginfo_t native_api;
siginfo_t linux_api;
} si;
memset(&si, 0, sizeof(si));
si.native_api.si_signo = sig;
si.native_api.si_errno = VIRTUAL_PERF_COUNTER_SIGNAL_SI_ERRNO;
LOG(debug) << "Synthesizing vpmc signal " << si.linux_api;
t->stash_synthetic_sig(si.linux_api, NONDETERMINISTIC_SIG);
disable_interrupt();
}
/* static */
VirtualPerfCounterMonitor*
VirtualPerfCounterMonitor::interrupting_virtual_pmc_for_task(Task* t) {
auto found = tasks_with_interrupts.find(t->tuid());
if (found == tasks_with_interrupts.end()) {
return nullptr;
}
return found->second;
}
} // namespace rr