debug.c

  1// SPDX-License-Identifier: GPL-2.0
  2/* For general debugging purposes */
  3
  4#include <inttypes.h>
  5#include <string.h>
  6#include <stdarg.h>
  7#include <stdio.h>
  8#include <stdlib.h>
  9#include <sys/wait.h>
 10#include <api/debug.h>
 11#include <linux/kernel.h>
 12#include <linux/time64.h>
 13#include <sys/time.h>
 14#ifdef HAVE_BACKTRACE_SUPPORT
 15#include <execinfo.h>
 16#endif
 17#include "addr_location.h"
 18#include "color.h"
 19#include "debug.h"
 20#include "env.h"
 21#include "event.h"
 22#include "machine.h"
 23#include "map.h"
 24#include "print_binary.h"
 25#include "srcline.h"
 26#include "symbol.h"
 27#include "synthetic-events.h"
 28#include "target.h"
 29#include "thread.h"
 30#include "trace-event.h"
 31#include "ui/helpline.h"
 32#include "ui/ui.h"
 33#include "util/parse-sublevel-options.h"
 34
 35#include <linux/ctype.h>
 36
 37#ifdef HAVE_LIBTRACEEVENT
 38#include <event-parse.h>
 39#else
 40#define LIBTRACEEVENT_VERSION 0
 41#endif
 42
 43int verbose;
 44int debug_kmaps;
 45int debug_peo_args;
 46bool dump_trace = false, quiet = false;
 47int debug_ordered_events;
 48static int redirect_to_stderr;
 49int debug_data_convert;
 50static FILE *_debug_file;
 51bool debug_display_time;
 52int debug_type_profile;
 53
 54FILE *debug_file(void)
 55{
 56	if (!_debug_file) {
 57		debug_set_file(stderr);
 58		pr_warning_once("debug_file not set");
 59	}
 60	return _debug_file;
 61}
 62
 63void debug_set_file(FILE *file)
 64{
 65	_debug_file = file;
 66}
 67
 68void debug_set_display_time(bool set)
 69{
 70	debug_display_time = set;
 71}
 72
 73static int fprintf_time(FILE *file)
 74{
 75	struct timeval tod;
 76	struct tm ltime;
 77	char date[64];
 78
 79	if (!debug_display_time)
 80		return 0;
 81
 82	if (gettimeofday(&tod, NULL) != 0)
 83		return 0;
 84
 85	if (localtime_r(&tod.tv_sec, &ltime) == NULL)
 86		return 0;
 87
 88	strftime(date, sizeof(date),  "%F %H:%M:%S", &ltime);
 89	return fprintf(file, "[%s.%06lu] ", date, (long)tod.tv_usec);
 90}
 91
 92int veprintf(int level, int var, const char *fmt, va_list args)
 93{
 94	int ret = 0;
 95
 96	if (var >= level) {
 97		if (use_browser >= 1 && !redirect_to_stderr) {
 98			ui_helpline__vshow(fmt, args);
 99		} else {
100			ret = fprintf_time(debug_file());
101			ret += vfprintf(debug_file(), fmt, args);
102		}
103	}
104
105	return ret;
106}
107
108int eprintf(int level, int var, const char *fmt, ...)
109{
110	va_list args;
111	int ret;
112
113	va_start(args, fmt);
114	ret = veprintf(level, var, fmt, args);
115	va_end(args);
116
117	return ret;
118}
119
120static int veprintf_time(u64 t, const char *fmt, va_list args)
121{
122	int ret = 0;
123	u64 secs, usecs, nsecs = t;
124
125	secs   = nsecs / NSEC_PER_SEC;
126	nsecs -= secs  * NSEC_PER_SEC;
127	usecs  = nsecs / NSEC_PER_USEC;
128
129	ret = fprintf(debug_file(), "[%13" PRIu64 ".%06" PRIu64 "] ", secs, usecs);
130	ret += vfprintf(debug_file(), fmt, args);
131	return ret;
132}
133
134int eprintf_time(int level, int var, u64 t, const char *fmt, ...)
135{
136	int ret = 0;
137	va_list args;
138
139	if (var >= level) {
140		va_start(args, fmt);
141		ret = veprintf_time(t, fmt, args);
142		va_end(args);
143	}
144
145	return ret;
146}
147
148/*
149 * Overloading libtraceevent standard info print
150 * function, display with -v in perf.
151 */
152void pr_stat(const char *fmt, ...)
153{
154	va_list args;
155
156	va_start(args, fmt);
157	veprintf(1, verbose, fmt, args);
158	va_end(args);
159	eprintf(1, verbose, "\n");
160}
161
162int dump_printf(const char *fmt, ...)
163{
164	va_list args;
165	int ret = 0;
166
167	if (dump_trace) {
168		va_start(args, fmt);
169		ret = vprintf(fmt, args);
170		va_end(args);
171	}
172
173	return ret;
174}
175
176static int trace_event_printer(enum binary_printer_ops op,
177			       unsigned int val, void *extra, FILE *fp)
178{
179	const char *color = PERF_COLOR_BLUE;
180	union perf_event *event = (union perf_event *)extra;
181	unsigned char ch = (unsigned char)val;
182	int printed = 0;
183
184	switch (op) {
185	case BINARY_PRINT_DATA_BEGIN:
186		printed += fprintf(fp, ".");
187		printed += color_fprintf(fp, color, "\n. ... raw event: size %d bytes\n",
188					 event->header.size);
189		break;
190	case BINARY_PRINT_LINE_BEGIN:
191		printed += fprintf(fp, ".");
192		break;
193	case BINARY_PRINT_ADDR:
194		printed += color_fprintf(fp, color, "  %04x: ", val);
195		break;
196	case BINARY_PRINT_NUM_DATA:
197		printed += color_fprintf(fp, color, " %02x", val);
198		break;
199	case BINARY_PRINT_NUM_PAD:
200		printed += color_fprintf(fp, color, "   ");
201		break;
202	case BINARY_PRINT_SEP:
203		printed += color_fprintf(fp, color, "  ");
204		break;
205	case BINARY_PRINT_CHAR_DATA:
206		printed += color_fprintf(fp, color, "%c",
207			      isprint(ch) && isascii(ch) ? ch : '.');
208		break;
209	case BINARY_PRINT_CHAR_PAD:
210		printed += color_fprintf(fp, color, " ");
211		break;
212	case BINARY_PRINT_LINE_END:
213		printed += color_fprintf(fp, color, "\n");
214		break;
215	case BINARY_PRINT_DATA_END:
216		printed += fprintf(fp, "\n");
217		break;
218	default:
219		break;
220	}
221
222	return printed;
223}
224
225void trace_event(union perf_event *event)
226{
227	unsigned char *raw_event = (void *)event;
228
229	if (!dump_trace)
230		return;
231
232	print_binary(raw_event, event->header.size, 16,
233		     trace_event_printer, event);
234}
235
236static struct sublevel_option debug_opts[] = {
237	{ .name = "verbose",		.value_ptr = &verbose },
238	{ .name = "ordered-events",	.value_ptr = &debug_ordered_events},
239	{ .name = "stderr",		.value_ptr = &redirect_to_stderr},
240	{ .name = "data-convert",	.value_ptr = &debug_data_convert },
241	{ .name = "perf-event-open",	.value_ptr = &debug_peo_args },
242	{ .name = "kmaps",		.value_ptr = &debug_kmaps },
243	{ .name = "type-profile",	.value_ptr = &debug_type_profile },
244	{ .name = NULL, }
245};
246
247int perf_debug_option(const char *str)
248{
249	int ret;
250
251	ret = perf_parse_sublevel_options(str, debug_opts);
252	if (ret)
253		return ret;
254
255	/* Allow only verbose value in range (0, 10), otherwise set 0. */
256	verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
257
258#if LIBTRACEEVENT_VERSION >= MAKE_LIBTRACEEVENT_VERSION(1, 3, 0)
259	if (verbose == 1)
260		tep_set_loglevel(TEP_LOG_INFO);
261	else if (verbose == 2)
262		tep_set_loglevel(TEP_LOG_DEBUG);
263	else if (verbose >= 3)
264		tep_set_loglevel(TEP_LOG_ALL);
265#endif
266	return 0;
267}
268
269int perf_quiet_option(void)
270{
271	struct sublevel_option *opt = &debug_opts[0];
272
273	/* disable all debug messages */
274	while (opt->name) {
275		*opt->value_ptr = -1;
276		opt++;
277	}
278
279	/* For debug variables that are used as bool types, set to 0. */
280	redirect_to_stderr = 0;
281	debug_peo_args = 0;
282	debug_kmaps = 0;
283	debug_type_profile = 0;
284
285	return 0;
286}
287
288#define DEBUG_WRAPPER(__n, __l)				\
289static int pr_ ## __n ## _wrapper(const char *fmt, ...)	\
290{							\
291	va_list args;					\
292	int ret;					\
293							\
294	va_start(args, fmt);				\
295	ret = veprintf(__l, verbose, fmt, args);	\
296	va_end(args);					\
297	return ret;					\
298}
299
300DEBUG_WRAPPER(warning, 0);
301DEBUG_WRAPPER(debug, 1);
302
303void perf_debug_setup(void)
304{
305	debug_set_file(stderr);
306	libapi_set_print(pr_warning_wrapper, pr_warning_wrapper, pr_debug_wrapper);
307}
308
309void __dump_stack(FILE *file, void **stackdump, size_t stackdump_size)
310{
311	/* TODO: async safety. printf, malloc, etc. aren't safe inside a signal handler. */
312	pid_t pid = getpid();
313	struct machine *machine;
314	struct thread *thread = NULL;
315	struct perf_env host_env;
316
317	perf_env__init(&host_env);
318	machine = machine__new_live(&host_env, /*kernel_maps=*/false, pid);
319
320	if (machine)
321		thread = machine__find_thread(machine, pid, pid);
322
323#ifdef HAVE_BACKTRACE_SUPPORT
324	if (!machine || !thread) {
325		/*
326		 * Backtrace functions are async signal safe. Fall back on them
327		 * if machine/thread creation fails.
328		 */
329		backtrace_symbols_fd(stackdump, stackdump_size, fileno(file));
330		machine__delete(machine);
331		perf_env__exit(&host_env);
332		return;
333	}
334#endif
335
336	for (size_t i = 0; i < stackdump_size; i++) {
337		struct addr_location al;
338		u64 addr = (u64)(uintptr_t)stackdump[i];
339		bool printed = false;
340
341		addr_location__init(&al);
342		if (thread && thread__find_map(thread, PERF_RECORD_MISC_USER, addr, &al)) {
343			al.sym = map__find_symbol(al.map, al.addr);
344			if (al.sym) {
345				fprintf(file, "    #%zd %p in %s ", i, stackdump[i], al.sym->name);
346				printed = true;
347			}
348		}
349		if (!printed)
350			fprintf(file, "    #%zd %p ", i, stackdump[i]);
351
352		map__fprintf_srcline(al.map, al.addr, "", file);
353		fprintf(file, "\n");
354		addr_location__exit(&al);
355	}
356	thread__put(thread);
357	machine__delete(machine);
358	perf_env__exit(&host_env);
359}
360
361/* Obtain a backtrace and print it to stdout. */
362#ifdef HAVE_BACKTRACE_SUPPORT
363void dump_stack(void)
364{
365	void *stackdump[32];
366	size_t size = backtrace(stackdump, ARRAY_SIZE(stackdump));
367
368	__dump_stack(stdout, stackdump, size);
369}
370#else
371void dump_stack(void) {}
372#endif
373
374void sighandler_dump_stack(int sig)
375{
376	psignal(sig, "perf");
377	dump_stack();
378	signal(sig, SIG_DFL);
379	raise(sig);
380}