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1 /*
2  * Copyright (c) 2013 Ben Noordhuis <info@bnoordhuis.nl>
3  * Copyright (c) 2013-2015 Dmitry V. Levin <ldv@altlinux.org>
4  * Copyright (c) 2016 Eugene Syromyatnikov <evgsyr@gmail.com>
5  * Copyright (c) 2015-2018 The strace developers.
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  * 3. The name of the author may not be used to endorse or promote products
17  *    derived from this software without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
20  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
21  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
22  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
23  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
24  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
28  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29  */
30 
31 #include "defs.h"
32 
33 #include "perf_event_struct.h"
34 #include "print_fields.h"
35 
36 #include "xlat/hw_breakpoint_len.h"
37 #include "xlat/hw_breakpoint_type.h"
38 #include "xlat/perf_attr_size.h"
39 #include "xlat/perf_branch_sample_type.h"
40 #include "xlat/perf_event_open_flags.h"
41 #include "xlat/perf_event_read_format.h"
42 #include "xlat/perf_event_sample_format.h"
43 #include "xlat/perf_hw_cache_id.h"
44 #include "xlat/perf_hw_cache_op_id.h"
45 #include "xlat/perf_hw_cache_op_result_id.h"
46 #include "xlat/perf_hw_id.h"
47 #include "xlat/perf_sw_ids.h"
48 #include "xlat/perf_type_id.h"
49 
50 struct pea_desc {
51 	struct perf_event_attr *attr;
52 	uint32_t size;
53 };
54 
55 static void
free_pea_desc(void * pea_desc_ptr)56 free_pea_desc(void *pea_desc_ptr)
57 {
58 	struct pea_desc *desc = pea_desc_ptr;
59 
60 	free(desc->attr);
61 	free(desc);
62 }
63 
64 int
fetch_perf_event_attr(struct tcb * const tcp,const kernel_ulong_t addr)65 fetch_perf_event_attr(struct tcb *const tcp, const kernel_ulong_t addr)
66 {
67 	struct pea_desc *desc;
68 	struct perf_event_attr *attr;
69 	uint32_t size;
70 
71 	if (umove(tcp, addr + offsetof(struct perf_event_attr, size), &size)) {
72 		printaddr(addr);
73 		return 1;
74 	}
75 
76 	if (size > sizeof(*attr))
77 		size = sizeof(*attr);
78 
79 	if (!size)
80 		size = PERF_ATTR_SIZE_VER0;
81 
82 	/*
83 	 * Kernel (rightfully) deems invalid attribute structures with size less
84 	 * than first published format size, and we do the same.
85 	 */
86 	if (size < PERF_ATTR_SIZE_VER0) {
87 		printaddr(addr);
88 		return 1;
89 	}
90 
91 	if (abbrev(tcp))
92 		size = offsetofend(struct perf_event_attr, config);
93 
94 	/* Size should be multiple of 8, but kernel doesn't check for it */
95 	/* size &= ~7; */
96 
97 	attr = xcalloc(1, sizeof(*attr));
98 
99 	if (umoven_or_printaddr(tcp, addr, size, attr)) {
100 		free(attr);
101 
102 		return 1;
103 	}
104 
105 	desc = xmalloc(sizeof(*desc));
106 
107 	desc->attr = attr;
108 	desc->size = size;
109 
110 	set_tcb_priv_data(tcp, desc, free_pea_desc);
111 
112 	return 0;
113 }
114 
115 void
print_perf_event_attr(struct tcb * const tcp,const kernel_ulong_t addr)116 print_perf_event_attr(struct tcb *const tcp, const kernel_ulong_t addr)
117 {
118 	static const char *precise_ip_desc[] = {
119 		"arbitrary skid",
120 		"constant skid",
121 		"requested to have 0 skid",
122 		"must have 0 skid",
123 	};
124 
125 	struct pea_desc *desc;
126 	struct perf_event_attr *attr;
127 	uint32_t size;
128 	uint32_t new_size;
129 	int use_new_size = 0;
130 
131 	/*
132 	 * Amusingly, kernel accepts structures with only part of the field
133 	 * present, so we making check like this (instead of checking
134 	 * offsetofend against size) in order to print fields as kernel sees
135 	 * them. This also should work great on big endian architectures.
136 	 */
137 	#define _PERF_CHECK_FIELD(_field) \
138 		do { \
139 			if (offsetof(struct perf_event_attr, _field) >= size) \
140 				goto print_perf_event_attr_out; \
141 		} while (0)
142 
143 	desc = get_tcb_priv_data(tcp);
144 
145 	attr = desc->attr;
146 	size = desc->size;
147 
148 	/* The only error which expected to change size field currently */
149 	if (tcp->u_error == E2BIG) {
150 		if (umove(tcp, addr + offsetof(struct perf_event_attr, size),
151 		    &new_size))
152 			use_new_size = -1;
153 		else
154 			use_new_size = 1;
155 	}
156 
157 	PRINT_FIELD_XVAL("{", *attr, type, perf_type_id, "PERF_TYPE_???");
158 	PRINT_FIELD_XVAL(", ", *attr, size, perf_attr_size,
159 			 "PERF_ATTR_SIZE_???");
160 
161 	if (use_new_size) {
162 		tprints(" => ");
163 
164 		if (use_new_size > 0)
165 			printxval(perf_attr_size, new_size,
166 				  "PERF_ATTR_SIZE_???");
167 		else
168 			tprints("???");
169 	}
170 
171 	switch (attr->type) {
172 	case PERF_TYPE_HARDWARE:
173 		PRINT_FIELD_XVAL(", ", *attr, config, perf_hw_id,
174 				 "PERF_COUNT_HW_???");
175 		break;
176 	case PERF_TYPE_SOFTWARE:
177 		PRINT_FIELD_XVAL(", ", *attr, config, perf_sw_ids,
178 				 "PERF_COUNT_SW_???");
179 		break;
180 	case PERF_TYPE_TRACEPOINT:
181 		/*
182 		 * "The value to use in config can be obtained from under
183 		 * debugfs tracing/events/../../id if ftrace is enabled
184 		 * in the kernel."
185 		 */
186 		PRINT_FIELD_U(", ", *attr, config);
187 		break;
188 	case PERF_TYPE_HW_CACHE:
189 		/*
190 		 * (perf_hw_cache_id) | (perf_hw_cache_op_id << 8) |
191 		 * (perf_hw_cache_op_result_id << 16)
192 		 */
193 		tprints(", config=");
194 		printxval(perf_hw_cache_id, attr->config & 0xFF,
195 			  "PERF_COUNT_HW_CACHE_???");
196 		tprints("|");
197 		printxval(perf_hw_cache_op_id, (attr->config >> 8) & 0xFF,
198 			   "PERF_COUNT_HW_CACHE_OP_???");
199 		tprints("<<8|");
200 		/*
201 		 * Current code (see set_ext_hw_attr in arch/x86/events/core.c,
202 		 * tile_map_cache_event in arch/tile/kernel/perf_event.c,
203 		 * arc_pmu_cache_event in arch/arc/kernel/perf_event.c,
204 		 * hw_perf_cache_event in arch/blackfin/kernel/perf_event.c,
205 		 * _hw_perf_cache_event in arch/metag/kernel/perf/perf_event.c,
206 		 * mipspmu_map_cache_event in arch/mips/kernel/perf_event_mipsxx.c,
207 		 * hw_perf_cache_event in arch/powerpc/perf/core-book3s.c,
208 		 * hw_perf_cache_event in arch/powerpc/perf/core-fsl-emb.c,
209 		 * hw_perf_cache_event in arch/sh/kernel/perf_event.c,
210 		 * sparc_map_cache_event in arch/sparc/kernel/perf_event.c,
211 		 * xtensa_pmu_cache_event in arch/xtensa/kernel/perf_event.c,
212 		 * armpmu_map_cache_event in drivers/perf/arm_pmu.c) assumes
213 		 * that cache result is 8 bits in size.
214 		 */
215 		printxval(perf_hw_cache_op_result_id,
216 			  (attr->config >> 16) & 0xFF,
217 			  "PERF_COUNT_HW_CACHE_RESULT_???");
218 		tprints("<<16");
219 		if (attr->config >> 24) {
220 			tprintf("|%#" PRIx64 "<<24", attr->config >> 24);
221 			tprints_comment("PERF_COUNT_HW_CACHE_???");
222 		}
223 		break;
224 	case PERF_TYPE_RAW:
225 		/*
226 		 * "If type is PERF_TYPE_RAW, then a custom "raw" config
227 		 * value is needed. Most CPUs support events that are not
228 		 * covered by the "generalized" events. These are
229 		 * implementation defined; see your CPU manual (for example the
230 		 * Intel Volume 3B documentation or the AMD BIOS and Kernel
231 		 * Developer Guide). The libpfm4 library can be used to
232 		 * translate from the name in the architectural manuals
233 		 * to the raw hex value perf_event_open() expects in this
234 		 * field."
235 		 */
236 	case PERF_TYPE_BREAKPOINT:
237 		/*
238 		 * "If type is PERF_TYPE_BREAKPOINT, then leave config set
239 		 * to zero. Its parameters are set in other places."
240 		 */
241 	default:
242 		PRINT_FIELD_X(", ", *attr, config);
243 		break;
244 	}
245 
246 	if (abbrev(tcp))
247 		goto print_perf_event_attr_out;
248 
249 	if (attr->freq)
250 		PRINT_FIELD_U(", ", *attr, sample_freq);
251 	else
252 		PRINT_FIELD_U(", ", *attr, sample_period);
253 
254 	PRINT_FIELD_FLAGS(", ", *attr, sample_type, perf_event_sample_format,
255 			  "PERF_SAMPLE_???");
256 	PRINT_FIELD_FLAGS(", ", *attr, read_format, perf_event_read_format,
257 			  "PERF_FORMAT_???");
258 
259 	tprintf(", disabled=%u"
260 		", inherit=%u"
261 		", pinned=%u"
262 		", exclusive=%u"
263 		", exclusive_user=%u"
264 		", exclude_kernel=%u"
265 		", exclude_hv=%u"
266 		", exclude_idle=%u"
267 		", mmap=%u"
268 		", comm=%u"
269 		", freq=%u"
270 		", inherit_stat=%u"
271 		", enable_on_exec=%u"
272 		", task=%u"
273 		", watermark=%u"
274 		", precise_ip=%u",
275 		attr->disabled,
276 		attr->inherit,
277 		attr->pinned,
278 		attr->exclusive,
279 		attr->exclude_user,
280 		attr->exclude_kernel,
281 		attr->exclude_hv,
282 		attr->exclude_idle,
283 		attr->mmap,
284 		attr->comm,
285 		attr->freq,
286 		attr->inherit_stat,
287 		attr->enable_on_exec,
288 		attr->task,
289 		attr->watermark,
290 		attr->precise_ip);
291 	tprints_comment(precise_ip_desc[attr->precise_ip]);
292 	tprintf(", mmap_data=%u"
293 		", sample_id_all=%u"
294 		", exclude_host=%u"
295 		", exclude_guest=%u"
296 		", exclude_callchain_kernel=%u"
297 		", exclude_callchain_user=%u"
298 		", mmap2=%u"
299 		", comm_exec=%u"
300 		", use_clockid=%u"
301 		", context_switch=%u"
302 		", write_backward=%u"
303 		", namespaces=%u",
304 		attr->mmap_data,
305 		attr->sample_id_all,
306 		attr->exclude_host,
307 		attr->exclude_guest,
308 		attr->exclude_callchain_kernel,
309 		attr->exclude_callchain_user,
310 		attr->mmap2,
311 		attr->comm_exec,
312 		attr->use_clockid,
313 		attr->context_switch,
314 		attr->write_backward,
315 		attr->namespaces);
316 
317 	/*
318 	 * Print it only in case it is non-zero, since it may contain flags we
319 	 * are not aware about.
320 	 */
321 	if (attr->__reserved_1) {
322 		tprintf(", __reserved_1=%#" PRIx64,
323 			(uint64_t) attr->__reserved_1);
324 		tprints_comment("Bits 63..29");
325 	}
326 
327 	if (attr->watermark)
328 		PRINT_FIELD_U(", ", *attr, wakeup_watermark);
329 	else
330 		PRINT_FIELD_U(", ", *attr, wakeup_events);
331 
332 	if (attr->type == PERF_TYPE_BREAKPOINT)
333 		/* Any combination of R/W with X is deemed invalid */
334 		PRINT_FIELD_XVAL(", ", *attr, bp_type, hw_breakpoint_type,
335 				 (attr->bp_type <=
336 					(HW_BREAKPOINT_X | HW_BREAKPOINT_RW))
337 						? "HW_BREAKPOINT_INVALID"
338 						: "HW_BREAKPOINT_???");
339 
340 	if (attr->type == PERF_TYPE_BREAKPOINT)
341 		PRINT_FIELD_X(", ", *attr, bp_addr);
342 	else
343 		PRINT_FIELD_X(", ", *attr, config1);
344 
345 	/*
346 	 * Fields after bp_addr/config1 are optional and may not present; check
347 	 * against size is needed.
348 	 */
349 
350 	_PERF_CHECK_FIELD(bp_len);
351 	if (attr->type == PERF_TYPE_BREAKPOINT)
352 		PRINT_FIELD_U(", ", *attr, bp_len);
353 	else
354 		PRINT_FIELD_X(", ", *attr, config2);
355 
356 	_PERF_CHECK_FIELD(branch_sample_type);
357 	if (attr->sample_type & PERF_SAMPLE_BRANCH_STACK) {
358 		PRINT_FIELD_FLAGS(", ", *attr, branch_sample_type,
359 				  perf_branch_sample_type,
360 				  "PERF_SAMPLE_BRANCH_???");
361 	}
362 
363 	_PERF_CHECK_FIELD(sample_regs_user);
364 	/*
365 	 * "This bit mask defines the set of user CPU registers to dump on
366 	 * samples. The layout of the register mask is architecture-specific and
367 	 * described in the kernel header
368 	 * arch/ARCH/include/uapi/asm/perf_regs.h."
369 	 */
370 	PRINT_FIELD_X(", ", *attr, sample_regs_user);
371 
372 	_PERF_CHECK_FIELD(sample_stack_user);
373 	/*
374 	 * "size of the user stack to dump if PERF_SAMPLE_STACK_USER is
375 	 * specified."
376 	 */
377 	if (attr->sample_type & PERF_SAMPLE_STACK_USER)
378 		PRINT_FIELD_X(", ", *attr, sample_stack_user);
379 
380 	if (attr->use_clockid) {
381 		_PERF_CHECK_FIELD(clockid);
382 		PRINT_FIELD_XVAL(", ", *attr, clockid, clocknames, "CLOCK_???");
383 	}
384 
385 	_PERF_CHECK_FIELD(sample_regs_intr);
386 	PRINT_FIELD_X(", ", *attr, sample_regs_intr);
387 
388 	_PERF_CHECK_FIELD(aux_watermark);
389 	PRINT_FIELD_U(", ", *attr, aux_watermark);
390 
391 	_PERF_CHECK_FIELD(sample_max_stack);
392 	PRINT_FIELD_U(", ", *attr, sample_max_stack);
393 
394 	/* _PERF_CHECK_FIELD(__reserved_2);
395 	PRINT_FIELD_U(", ", *attr, __reserved2); */
396 
397 print_perf_event_attr_out:
398 	if ((attr->size && (attr->size > size)) ||
399 	    (!attr->size && (size < PERF_ATTR_SIZE_VER0)))
400 		tprints(", ...");
401 
402 	tprints("}");
403 }
404 
SYS_FUNC(perf_event_open)405 SYS_FUNC(perf_event_open)
406 {
407 	/*
408 	 * We try to copy out the whole structure on entering in order to check
409 	 * size value on exiting. We do not check the rest of the fields because
410 	 * they shouldn't be changed, but copy the whole structure instead
411 	 * of just size field because they could.
412 	 */
413 	if (entering(tcp)) {
414 		if (!fetch_perf_event_attr(tcp, tcp->u_arg[0]))
415 			return 0;
416 	} else {
417 		print_perf_event_attr(tcp, tcp->u_arg[0]);
418 	}
419 
420 	tprintf(", %d, %d, ",
421 		(int) tcp->u_arg[1],
422 		(int) tcp->u_arg[2]);
423 	printfd(tcp, tcp->u_arg[3]);
424 	tprints(", ");
425 	printflags64(perf_event_open_flags, tcp->u_arg[4], "PERF_FLAG_???");
426 
427 	return RVAL_DECODED | RVAL_FD;
428 }
429