summaryrefslogtreecommitdiffstats
blob: 11d3095ef6d20a39cd3c84e466d7c7c886c7cbbf (plain) (blame)
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
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
/**
 * Copyright (C) ARM Limited 2010-2014. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#define __STDC_FORMAT_MACROS

#include "DriverSource.h"

#include <fcntl.h>
#include <inttypes.h>
#include <sys/prctl.h>
#include <unistd.h>

#include "Buffer.h"
#include "Child.h"
#include "DynBuf.h"
#include "Fifo.h"
#include "Logging.h"
#include "Proc.h"
#include "Sender.h"
#include "SessionData.h"

extern Child *child;

DriverSource::DriverSource(sem_t *senderSem, sem_t *startProfile) : mBuffer(NULL), mFifo(NULL), mSenderSem(senderSem), mStartProfile(startProfile), mBufferSize(0), mBufferFD(0), mLength(1) {
	int driver_version = 0;

	mBuffer = new Buffer(0, FRAME_PERF_ATTRS, 4*1024*1024, senderSem);
	if (readIntDriver("/dev/gator/version", &driver_version) == -1) {
		logg->logError(__FILE__, __LINE__, "Error reading gator driver version");
		handleException();
	}

	// Verify the driver version matches the daemon version
	if (driver_version != PROTOCOL_VERSION) {
		if ((driver_version > PROTOCOL_DEV) || (PROTOCOL_VERSION > PROTOCOL_DEV)) {
			// One of the mismatched versions is development version
			logg->logError(__FILE__, __LINE__,
				"DEVELOPMENT BUILD MISMATCH: gator driver version \"%d\" is not in sync with gator daemon version \"%d\".\n"
				">> The following must be synchronized from engineering repository:\n"
				">> * gator driver\n"
				">> * gator daemon\n"
				">> * Streamline", driver_version, PROTOCOL_VERSION);
			handleException();
		} else {
			// Release version mismatch
			logg->logError(__FILE__, __LINE__,
				"gator driver version \"%d\" is different than gator daemon version \"%d\".\n"
				">> Please upgrade the driver and daemon to the latest versions.", driver_version, PROTOCOL_VERSION);
			handleException();
		}
	}

	int enable = -1;
	if (readIntDriver("/dev/gator/enable", &enable) != 0 || enable != 0) {
		logg->logError(__FILE__, __LINE__, "Driver already enabled, possibly a session is already in progress.");
		handleException();
	}

	readIntDriver("/dev/gator/cpu_cores", &gSessionData->mCores);
	if (gSessionData->mCores == 0) {
		gSessionData->mCores = 1;
	}

	if (readIntDriver("/dev/gator/buffer_size", &mBufferSize) || mBufferSize <= 0) {
		logg->logError(__FILE__, __LINE__, "Unable to read the driver buffer size");
		handleException();
	}
}

DriverSource::~DriverSource() {
	delete mFifo;

	// Write zero for safety, as a zero should have already been written
	writeDriver("/dev/gator/enable", "0");

	// Calls event_buffer_release in the driver
	if (mBufferFD) {
		close(mBufferFD);
	}
}

bool DriverSource::prepare() {
	// Create user-space buffers, add 5 to the size to account for the 1-byte type and 4-byte length
	logg->logMessage("Created %d MB collector buffer with a %d-byte ragged end", gSessionData->mTotalBufferSize, mBufferSize);
	mFifo = new Fifo(mBufferSize + 5, gSessionData->mTotalBufferSize*1024*1024, mSenderSem);

	return true;
}

void DriverSource::bootstrapThread() {
	prctl(PR_SET_NAME, (unsigned long)&"gatord-bootstrap", 0, 0, 0);

	DynBuf printb;
	DynBuf b1;
	DynBuf b2;
	DynBuf b3;

	if (!readProc(mBuffer, false, &printb, &b1, &b2, &b3)) {
		logg->logMessage("%s(%s:%i): readProc failed", __FUNCTION__, __FILE__, __LINE__);
		handleException();
	}

	mBuffer->commit(1);
	mBuffer->setDone();
}

void *DriverSource::bootstrapThreadStatic(void *arg) {
	static_cast<DriverSource *>(arg)->bootstrapThread();
	return NULL;
}

void DriverSource::run() {
	// Get the initial pointer to the collect buffer
	char *collectBuffer = mFifo->start();
	int bytesCollected = 0;

	logg->logMessage("********** Profiling started **********");

	// Set the maximum backtrace depth
	if (writeReadDriver("/dev/gator/backtrace_depth", &gSessionData->mBacktraceDepth)) {
		logg->logError(__FILE__, __LINE__, "Unable to set the driver backtrace depth");
		handleException();
	}

	// open the buffer which calls userspace_buffer_open() in the driver
	mBufferFD = open("/dev/gator/buffer", O_RDONLY);
	if (mBufferFD < 0) {
		logg->logError(__FILE__, __LINE__, "The gator driver did not set up properly. Please view the linux console or dmesg log for more information on the failure.");
		handleException();
	}

	// set the tick rate of the profiling timer
	if (writeReadDriver("/dev/gator/tick", &gSessionData->mSampleRate) != 0) {
		logg->logError(__FILE__, __LINE__, "Unable to set the driver tick");
		handleException();
	}

	// notify the kernel of the response type
	int response_type = gSessionData->mLocalCapture ? 0 : RESPONSE_APC_DATA;
	if (writeDriver("/dev/gator/response_type", response_type)) {
		logg->logError(__FILE__, __LINE__, "Unable to write the response type");
		handleException();
	}

	// Set the live rate
	if (writeReadDriver("/dev/gator/live_rate", &gSessionData->mLiveRate)) {
		logg->logError(__FILE__, __LINE__, "Unable to set the driver live rate");
		handleException();
	}

	logg->logMessage("Start the driver");

	// This command makes the driver start profiling by calling gator_op_start() in the driver
	if (writeDriver("/dev/gator/enable", "1") != 0) {
		logg->logError(__FILE__, __LINE__, "The gator driver did not start properly. Please view the linux console or dmesg log for more information on the failure.");
		handleException();
	}

	lseek(mBufferFD, 0, SEEK_SET);

	sem_post(mStartProfile);

	pthread_t bootstrapThreadID;
	if (pthread_create(&bootstrapThreadID, NULL, bootstrapThreadStatic, this) != 0) {
		logg->logError(__FILE__, __LINE__, "Unable to start the gator_bootstrap thread");
		handleException();
	}

	// Collect Data
	do {
		// This command will stall until data is received from the driver
		// Calls event_buffer_read in the driver
		errno = 0;
		bytesCollected = read(mBufferFD, collectBuffer, mBufferSize);

		// If read() returned due to an interrupt signal, re-read to obtain the last bit of collected data
		if (bytesCollected == -1 && errno == EINTR) {
			bytesCollected = read(mBufferFD, collectBuffer, mBufferSize);
		}

		// return the total bytes written
		logg->logMessage("Driver read of %d bytes", bytesCollected);

		// In one shot mode, stop collection once all the buffers are filled
		if (gSessionData->mOneShot && gSessionData->mSessionIsActive) {
			if (bytesCollected == -1 || mFifo->willFill(bytesCollected)) {
				logg->logMessage("One shot");
				child->endSession();
			}
		}
		collectBuffer = mFifo->write(bytesCollected);
	} while (bytesCollected > 0);

	logg->logMessage("Exit collect data loop");

	pthread_join(bootstrapThreadID, NULL);
}

void DriverSource::interrupt() {
	// This command should cause the read() function in collect() to return and stop the driver from profiling
	if (writeDriver("/dev/gator/enable", "0") != 0) {
		logg->logMessage("Stopping kernel failed");
	}
}

bool DriverSource::isDone() {
	return mLength <= 0 && (mBuffer == NULL || mBuffer->isDone());
}

void DriverSource::write(Sender *sender) {
	char *data = mFifo->read(&mLength);
	if (data != NULL) {
		sender->writeData(data, mLength, RESPONSE_APC_DATA);
		mFifo->release();
		// Assume the summary packet is in the first block received from the driver
		gSessionData->mSentSummary = true;
	}
	if (mBuffer != NULL && !mBuffer->isDone()) {
		mBuffer->write(sender);
		if (mBuffer->isDone()) {
			Buffer *buf = mBuffer;
			mBuffer = NULL;
			delete buf;
		}
	}
}

int DriverSource::readIntDriver(const char *fullpath, int *value) {
	char data[40]; // Sufficiently large to hold any integer
	const int fd = open(fullpath, O_RDONLY);
	if (fd < 0) {
		return -1;
	}

	const ssize_t bytes = read(fd, data, sizeof(data) - 1);
	close(fd);
	if (bytes < 0) {
		return -1;
	}
	data[bytes] = '\0';

	char *endptr;
	errno = 0;
	*value = strtol(data, &endptr, 10);
	if (errno != 0 || *endptr != '\n') {
		logg->logMessage("Invalid value in file %s", fullpath);
		return -1;
	}

	return 0;
}

int DriverSource::readInt64Driver(const char *fullpath, int64_t *value) {
	char data[40]; // Sufficiently large to hold any integer
	const int fd = open(fullpath, O_RDONLY);
	if (fd < 0) {
		return -1;
	}

	const ssize_t bytes = read(fd, data, sizeof(data) - 1);
	close(fd);
	if (bytes < 0) {
		return -1;
	}
	data[bytes] = '\0';

	char *endptr;
	errno = 0;
	*value = strtoll(data, &endptr, 10);
	if (errno != 0 || (*endptr != '\n' && *endptr != '\0')) {
		logg->logMessage("Invalid value in file %s", fullpath);
		return -1;
	}

	return 0;
}

int DriverSource::writeDriver(const char *fullpath, const char *data) {
	int fd = open(fullpath, O_WRONLY);
	if (fd < 0) {
		return -1;
	}
	if (::write(fd, data, strlen(data)) < 0) {
		close(fd);
		logg->logMessage("Opened but could not write to %s", fullpath);
		return -1;
	}
	close(fd);
	return 0;
}

int DriverSource::writeDriver(const char *path, int value) {
	char data[40]; // Sufficiently large to hold any integer
	snprintf(data, sizeof(data), "%d", value);
	return writeDriver(path, data);
}

int DriverSource::writeDriver(const char *path, int64_t value) {
	char data[40]; // Sufficiently large to hold any integer
	snprintf(data, sizeof(data), "%" PRIi64, value);
	return writeDriver(path, data);
}

int DriverSource::writeReadDriver(const char *path, int *value) {
	if (writeDriver(path, *value) || readIntDriver(path, value)) {
		return -1;
	}
	return 0;
}

int DriverSource::writeReadDriver(const char *path, int64_t *value) {
	if (writeDriver(path, *value) || readInt64Driver(path, value)) {
		return -1;
	}
	return 0;
}