xref: /optee_os/lib/libutee/arch/arm/gprof/gprof.c (revision 8e81e2f5366a971afdd2ac47fb8529d1def5feb0)
1 /*
2  * Copyright (c) 2016, Linaro Limited
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions are met:
7  *
8  * 1. Redistributions of source code must retain the above copyright notice,
9  * this list of conditions and the following disclaimer.
10  *
11  * 2. Redistributions in binary form must reproduce the above copyright notice,
12  * this list of conditions and the following disclaimer in the documentation
13  * and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
16  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
18  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
19  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
25  * POSSIBILITY OF SUCH DAMAGE.
26  */
27 
28 /*
29  * Portions of this file are adapted from glibc:
30  *   gmon/gmon.c
31  *   gmon/mcount.c
32  *
33  *-
34  * Copyright (c) 1983, 1992, 1993, 2011
35  *	The Regents of the University of California.  All rights reserved.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 4. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  */
61 
62 #include <assert.h>
63 #include <compiler.h>
64 #include <inttypes.h>
65 #include <malloc.h>
66 #include <stdint.h>
67 #include <string.h>
68 #include <tee_api_private.h>
69 #include <trace.h>
70 #include <user_ta_header.h>
71 #include <utee_types.h>
72 #include "gmon.h"
73 #include "gmon_out.h"
74 #include "gprof_pta.h"
75 
76 /* Defined by the linker script */
77 extern uint8_t __gprof_buf_end[];
78 extern uint8_t __gprof_buf_start[];
79 
80 static bool ta_instrumented(void)
81 {
82 	return (__gprof_buf_end != __gprof_buf_start);
83 }
84 
85 static void *gprof_alloc(size_t len)
86 {
87 	if (len > (size_t)(__gprof_buf_end - __gprof_buf_start))
88 		return NULL;
89 	return __gprof_buf_start;
90 }
91 
92 static struct gmonparam _gmonparam = { GMON_PROF_OFF };
93 
94 static uint32_t _gprof_file_id; /* File id returned by tee-supplicant */
95 
96 static int _gprof_s_scale;
97 #define SCALE_1_TO_1 0x10000L
98 
99 /* Adjust PC so that gprof can locate it in the TA ELF file */
100 static unsigned long __noprof adjust_pc(unsigned long pc)
101 {
102 	return pc - (unsigned long)__text_start + sizeof(struct ta_head);
103 }
104 
105 void __utee_gprof_init(void)
106 {
107 	unsigned long lowpc;
108 	unsigned long highpc;
109 	struct gmonparam *p = &_gmonparam;
110 	size_t bufsize;
111 	TEE_Result res;
112 	char *cp;
113 
114 	if (!ta_instrumented())
115 		return;
116 
117 	lowpc = adjust_pc((unsigned long)__text_start);
118 	highpc = adjust_pc((unsigned long)__text_end);
119 
120 	/*
121 	 * Round lowpc and highpc to multiples of the density we're using
122 	 * so the rest of the scaling (here and in gprof) stays in ints.
123 	 */
124 	p->lowpc = ROUNDDOWN(lowpc, HISTFRACTION * sizeof(HISTCOUNTER));
125 	p->highpc = ROUNDUP(highpc, HISTFRACTION * sizeof(HISTCOUNTER));
126 	p->textsize = p->highpc - p->lowpc;
127 	p->kcountsize = ROUNDUP(p->textsize / HISTFRACTION, sizeof(*p->froms));
128 	p->hashfraction = HASHFRACTION;
129 	p->log_hashfraction = -1;
130 	/*
131 	 * The following test must be kept in sync with the corresponding
132 	 * test in __mcount_internal
133 	 */
134 	if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) {
135 		/*
136 		 * If HASHFRACTION is a power of two, mcount can use shifting
137 		 * instead of integer division. Precompute shift amount.
138 		 */
139 		p->log_hashfraction = __builtin_ffs(p->hashfraction *
140 						    sizeof(*p->froms)) - 1;
141 	}
142 	p->fromssize = p->textsize / HASHFRACTION;
143 	p->tolimit = p->textsize * ARCDENSITY / 100;
144 	if (p->tolimit < MINARCS)
145 		p->tolimit = MINARCS;
146 	else if (p->tolimit > MAXARCS)
147 		p->tolimit = MAXARCS;
148 	p->tossize = p->tolimit * sizeof(struct tostruct);
149 
150 	bufsize = p->kcountsize + p->fromssize + p->tossize;
151 
152 	IMSG("gprof: initializing");
153 	DMSG("TA text size: %zu, gprof buffer size: %zu",
154 	     __text_end - __text_start, bufsize);
155 
156 	cp = gprof_alloc(bufsize);
157 	if (!cp) {
158 		EMSG("gprof: could not allocate profiling buffer");
159 		p->tos = NULL;
160 		p->state = GMON_PROF_ERROR;
161 		return;
162 	}
163 
164 	p->tos = (struct tostruct *)cp;
165 	cp += p->tossize;
166 	p->kcount = (HISTCOUNTER *)cp;
167 	cp += p->kcountsize;
168 	p->froms = (ARCINDEX *)cp;
169 
170 	p->tos[0].link = 0;
171 
172 	if (p->kcountsize < p->textsize)
173 		_gprof_s_scale = ((float)p->kcountsize / p->textsize) *
174 				  SCALE_1_TO_1;
175 	else
176 		_gprof_s_scale = SCALE_1_TO_1;
177 
178 	res = __pta_gprof_pc_sampling_start(p->kcount, p->kcountsize,
179 					    p->lowpc +
180 					    ((unsigned long)__text_start -
181 						sizeof(struct ta_head)),
182 					    _gprof_s_scale);
183 	if (res != TEE_SUCCESS)
184 		EMSG("gprof: could not start PC sampling (0x%08x)", res);
185 
186 	p->state = GMON_PROF_ON;
187 }
188 
189 static void _gprof_write_buf(void *buf, size_t size)
190 {
191 	TEE_Result res;
192 
193 	res = __pta_gprof_send(buf, size, &_gprof_file_id);
194 	if (res != TEE_SUCCESS)
195 		EMSG("gprof: could not send gprof data (0x%08x)", res);
196 }
197 
198 static void _gprof_write_header(void)
199 {
200 	struct gmon_hdr ghdr;
201 	size_t size = sizeof(struct gmon_hdr);
202 
203 	memcpy(&ghdr.cookie[0], GMON_MAGIC, sizeof(ghdr.cookie));
204 	ghdr.version = GMON_VERSION;
205 	memset(ghdr.spare, '\0', sizeof(ghdr.spare));
206 
207 	_gprof_write_buf(&ghdr, size);
208 }
209 
210 static void _gprof_write_hist(void)
211 {
212 	struct out_record {
213 		uint8_t tag;
214 		struct gmon_hist_hdr hist_hdr;
215 	} __packed out = {
216 		.tag = GMON_TAG_TIME_HIST,
217 		.hist_hdr = {
218 			.low_pc = _gmonparam.lowpc,
219 			.high_pc = _gmonparam.highpc,
220 			.hist_size = _gmonparam.kcountsize/sizeof(HISTCOUNTER),
221 			.prof_rate = _gmonparam.prof_rate,
222 			.dimen = "seconds",
223 			.dimen_abbrev = 's',
224 		}
225 	};
226 
227 	_gprof_write_buf(&out, sizeof(out));
228 	_gprof_write_buf(_gmonparam.kcount, _gmonparam.kcountsize);
229 }
230 
231 static void _gprof_write_call_graph(void)
232 {
233 #define NARCS_PER_WRITE 16
234 	struct out_record {
235 		uint8_t tag;
236 		uint8_t data[sizeof(struct gmon_cg_arc_record)];
237 	} out[NARCS_PER_WRITE];
238 	struct gmon_cg_arc_record arc;
239 	ARCINDEX from_index, to_index;
240 	unsigned long from_len;
241 	unsigned long frompc;
242 	int nfilled = 0;
243 
244 	from_len = _gmonparam.fromssize / sizeof(*_gmonparam.froms);
245 
246 	for (from_index = 0; from_index < from_len; ++from_index) {
247 
248 		if (_gmonparam.froms[from_index] == 0)
249 			continue;
250 
251 		frompc = _gmonparam.lowpc;
252 		frompc += (from_index * _gmonparam.hashfraction
253 			   * sizeof(*_gmonparam.froms));
254 		for (to_index = _gmonparam.froms[from_index];
255 		     to_index != 0;
256 		     to_index = _gmonparam.tos[to_index].link) {
257 
258 			arc.from_pc = frompc;
259 			arc.self_pc = _gmonparam.tos[to_index].selfpc;
260 			arc.count = _gmonparam.tos[to_index].count;
261 
262 			out[nfilled].tag = GMON_TAG_CG_ARC;
263 			memcpy(out[nfilled].data, &arc, sizeof(arc));
264 
265 			if (++nfilled == NARCS_PER_WRITE) {
266 				_gprof_write_buf(out, sizeof(out));
267 				nfilled = 0;
268 			}
269 		}
270 	}
271 	if (nfilled > 0)
272 		_gprof_write_buf(out, nfilled * sizeof(out[0]));
273 }
274 
275 /* Stop profiling and send profile data in gmon.out format to Normal World */
276 void __utee_gprof_fini(void)
277 {
278 	TEE_Result res;
279 
280 	if (_gmonparam.state != GMON_PROF_ON)
281 		return;
282 
283 	/* Stop call graph tracing */
284 	_gmonparam.state = GMON_PROF_OFF_EXITING;
285 
286 	/* Stop TA sampling */
287 	res = __pta_gprof_pc_sampling_stop(&_gmonparam.prof_rate);
288 
289 	_gprof_write_header();
290 	if (res == TEE_SUCCESS)
291 		_gprof_write_hist();
292 	_gprof_write_call_graph();
293 
294 	__pta_gprof_fini();
295 }
296 
297 /*
298  * Called from the assembly stub (_mcount or __gnu_mcount_nc).
299  *
300  * __mcount_internal updates data structures that represent traversals of the
301  * program's call graph edges.  frompc and selfpc are the return
302  * address and function address that represents the given call graph edge.
303  */
304 void __noprof __mcount_internal(unsigned long frompc, unsigned long selfpc)
305 {
306 	ARCINDEX *frompcindex;
307 	struct tostruct *top, *prevtop;
308 	struct gmonparam *p;
309 	ARCINDEX toindex;
310 	int i;
311 
312 	p = &_gmonparam;
313 
314 	/*
315 	 * Check that we are profiling and that we aren't recursively invoked.
316 	 */
317 	if (p->state != GMON_PROF_ON)
318 		return;
319 	p->state = GMON_PROF_BUSY;
320 
321 	frompc = adjust_pc(frompc);
322 	selfpc = adjust_pc(selfpc);
323 
324 	/* Check that frompcindex is a reasonable pc value. */
325 	frompc -= p->lowpc;
326 	if (frompc > p->textsize)
327 		goto done;
328 
329 	/* Note: keep in sync. with the initialization function above */
330 	if ((HASHFRACTION & (HASHFRACTION - 1)) == 0) {
331 		/* Avoid integer divide if possible */
332 		i = frompc >> p->log_hashfraction;
333 	} else {
334 		i = frompc / (p->hashfraction * sizeof(*p->froms));
335 	}
336 	frompcindex = &p->froms[i];
337 	toindex = *frompcindex;
338 	if (toindex == 0) {
339 		/* First time traversing this arc */
340 		toindex = ++p->tos[0].link;
341 		if (toindex >= p->tolimit) {
342 			/* Halt further profiling */
343 			goto overflow;
344 		}
345 
346 		*frompcindex = toindex;
347 		top = &p->tos[toindex];
348 		top->selfpc = selfpc;
349 		top->count = 1;
350 		top->link = 0;
351 		goto done;
352 	}
353 	top = &p->tos[toindex];
354 	if (top->selfpc == selfpc) {
355 		/* Arc at front of chain; usual case */
356 		top->count++;
357 		goto done;
358 	}
359 	/*
360 	 * Have to go looking down chain for it.
361 	 * top points to what we are looking at,
362 	 * prevtop points to previous top.
363 	 * we know it is not at the head of the chain.
364 	 */
365 	for (;;) {
366 		if (top->link == 0) {
367 			/*
368 			 * top is end of the chain and none of the chain
369 			 * had top->selfpc == selfpc.
370 			 * so we allocate a new tostruct
371 			 * and link it to the head of the chain.
372 			 */
373 			toindex = ++p->tos[0].link;
374 			if (toindex >= p->tolimit)
375 				goto overflow;
376 
377 			top = &p->tos[toindex];
378 			top->selfpc = selfpc;
379 			top->count = 1;
380 			top->link = *frompcindex;
381 			*frompcindex = toindex;
382 			goto done;
383 		}
384 		/*
385 		 * Otherwise, check the next arc on the chain.
386 		 */
387 		prevtop = top;
388 		top = &p->tos[top->link];
389 		if (top->selfpc == selfpc) {
390 			/*
391 			 * There it is. Increment its count, move it to the
392 			 * head of the chain.
393 			 */
394 			top->count++;
395 			toindex = prevtop->link;
396 			prevtop->link = top->link;
397 			top->link = *frompcindex;
398 			*frompcindex = toindex;
399 			goto done;
400 		}
401 	}
402 done:
403 	p->state = GMON_PROF_ON;
404 	return;
405 overflow:
406 	p->state = GMON_PROF_ERROR;
407 }
408