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	In debug_file, pr_warning_once is called on error. As that function
calls debug_file the function will yield a stack overflow. Switch the
location of the call so the recursion is avoided.
Reviewed-by: Howard Chu <howardchu95@gmail.com>
Signed-off-by: Ian Rogers <irogers@google.com>
Reviewed-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/r/20250228222308.626803-2-irogers@google.com
Fixes: ec49230cf6 ("perf debug: Expose debug file")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
		
	
			
		
			
				
	
	
		
			327 lines
		
	
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			327 lines
		
	
	
	
		
			6.6 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/* For general debugging purposes */
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#include <inttypes.h>
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#include <string.h>
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#include <stdarg.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <sys/wait.h>
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#include <api/debug.h>
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#include <linux/kernel.h>
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#include <linux/time64.h>
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#include <sys/time.h>
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#ifdef HAVE_BACKTRACE_SUPPORT
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#include <execinfo.h>
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#endif
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#include "color.h"
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#include "event.h"
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#include "debug.h"
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#include "print_binary.h"
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#include "target.h"
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#include "trace-event.h"
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#include "ui/helpline.h"
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#include "ui/ui.h"
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#include "util/parse-sublevel-options.h"
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#include <linux/ctype.h>
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#ifdef HAVE_LIBTRACEEVENT
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#include <event-parse.h>
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#else
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#define LIBTRACEEVENT_VERSION 0
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#endif
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int verbose;
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int debug_kmaps;
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int debug_peo_args;
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bool dump_trace = false, quiet = false;
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int debug_ordered_events;
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static int redirect_to_stderr;
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int debug_data_convert;
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static FILE *_debug_file;
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bool debug_display_time;
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int debug_type_profile;
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FILE *debug_file(void)
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{
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	if (!_debug_file) {
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		debug_set_file(stderr);
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		pr_warning_once("debug_file not set");
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	}
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	return _debug_file;
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}
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void debug_set_file(FILE *file)
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{
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	_debug_file = file;
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}
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void debug_set_display_time(bool set)
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{
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	debug_display_time = set;
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}
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static int fprintf_time(FILE *file)
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{
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	struct timeval tod;
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	struct tm ltime;
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	char date[64];
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	if (!debug_display_time)
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		return 0;
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	if (gettimeofday(&tod, NULL) != 0)
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		return 0;
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	if (localtime_r(&tod.tv_sec, <ime) == NULL)
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		return 0;
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	strftime(date, sizeof(date),  "%F %H:%M:%S", <ime);
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	return fprintf(file, "[%s.%06lu] ", date, (long)tod.tv_usec);
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}
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int veprintf(int level, int var, const char *fmt, va_list args)
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{
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	int ret = 0;
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	if (var >= level) {
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		if (use_browser >= 1 && !redirect_to_stderr) {
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			ui_helpline__vshow(fmt, args);
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		} else {
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			ret = fprintf_time(debug_file());
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			ret += vfprintf(debug_file(), fmt, args);
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		}
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	}
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	return ret;
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}
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int eprintf(int level, int var, const char *fmt, ...)
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{
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	va_list args;
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	int ret;
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	va_start(args, fmt);
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	ret = veprintf(level, var, fmt, args);
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	va_end(args);
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	return ret;
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}
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static int veprintf_time(u64 t, const char *fmt, va_list args)
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{
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	int ret = 0;
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	u64 secs, usecs, nsecs = t;
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	secs   = nsecs / NSEC_PER_SEC;
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	nsecs -= secs  * NSEC_PER_SEC;
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	usecs  = nsecs / NSEC_PER_USEC;
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	ret = fprintf(debug_file(), "[%13" PRIu64 ".%06" PRIu64 "] ", secs, usecs);
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	ret += vfprintf(debug_file(), fmt, args);
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	return ret;
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}
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int eprintf_time(int level, int var, u64 t, const char *fmt, ...)
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{
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	int ret = 0;
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	va_list args;
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	if (var >= level) {
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		va_start(args, fmt);
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		ret = veprintf_time(t, fmt, args);
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		va_end(args);
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	}
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	return ret;
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}
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/*
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 * Overloading libtraceevent standard info print
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 * function, display with -v in perf.
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 */
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void pr_stat(const char *fmt, ...)
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{
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	va_list args;
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	va_start(args, fmt);
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	veprintf(1, verbose, fmt, args);
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	va_end(args);
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	eprintf(1, verbose, "\n");
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}
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int dump_printf(const char *fmt, ...)
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{
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	va_list args;
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	int ret = 0;
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	if (dump_trace) {
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		va_start(args, fmt);
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		ret = vprintf(fmt, args);
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		va_end(args);
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	}
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	return ret;
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}
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static int trace_event_printer(enum binary_printer_ops op,
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			       unsigned int val, void *extra, FILE *fp)
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{
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	const char *color = PERF_COLOR_BLUE;
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	union perf_event *event = (union perf_event *)extra;
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	unsigned char ch = (unsigned char)val;
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	int printed = 0;
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	switch (op) {
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	case BINARY_PRINT_DATA_BEGIN:
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		printed += fprintf(fp, ".");
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		printed += color_fprintf(fp, color, "\n. ... raw event: size %d bytes\n",
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					 event->header.size);
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		break;
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	case BINARY_PRINT_LINE_BEGIN:
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		printed += fprintf(fp, ".");
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		break;
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	case BINARY_PRINT_ADDR:
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		printed += color_fprintf(fp, color, "  %04x: ", val);
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		break;
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	case BINARY_PRINT_NUM_DATA:
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		printed += color_fprintf(fp, color, " %02x", val);
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		break;
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	case BINARY_PRINT_NUM_PAD:
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		printed += color_fprintf(fp, color, "   ");
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		break;
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	case BINARY_PRINT_SEP:
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		printed += color_fprintf(fp, color, "  ");
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		break;
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	case BINARY_PRINT_CHAR_DATA:
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		printed += color_fprintf(fp, color, "%c",
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			      isprint(ch) && isascii(ch) ? ch : '.');
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		break;
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	case BINARY_PRINT_CHAR_PAD:
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		printed += color_fprintf(fp, color, " ");
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		break;
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	case BINARY_PRINT_LINE_END:
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		printed += color_fprintf(fp, color, "\n");
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		break;
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	case BINARY_PRINT_DATA_END:
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		printed += fprintf(fp, "\n");
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		break;
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	default:
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		break;
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	}
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	return printed;
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}
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void trace_event(union perf_event *event)
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{
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	unsigned char *raw_event = (void *)event;
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	if (!dump_trace)
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		return;
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	print_binary(raw_event, event->header.size, 16,
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		     trace_event_printer, event);
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}
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static struct sublevel_option debug_opts[] = {
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	{ .name = "verbose",		.value_ptr = &verbose },
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	{ .name = "ordered-events",	.value_ptr = &debug_ordered_events},
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	{ .name = "stderr",		.value_ptr = &redirect_to_stderr},
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	{ .name = "data-convert",	.value_ptr = &debug_data_convert },
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	{ .name = "perf-event-open",	.value_ptr = &debug_peo_args },
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	{ .name = "kmaps",		.value_ptr = &debug_kmaps },
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	{ .name = "type-profile",	.value_ptr = &debug_type_profile },
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	{ .name = NULL, }
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};
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int perf_debug_option(const char *str)
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{
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	int ret;
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	ret = perf_parse_sublevel_options(str, debug_opts);
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	if (ret)
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		return ret;
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	/* Allow only verbose value in range (0, 10), otherwise set 0. */
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	verbose = (verbose < 0) || (verbose > 10) ? 0 : verbose;
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#if LIBTRACEEVENT_VERSION >= MAKE_LIBTRACEEVENT_VERSION(1, 3, 0)
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	if (verbose == 1)
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		tep_set_loglevel(TEP_LOG_INFO);
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	else if (verbose == 2)
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		tep_set_loglevel(TEP_LOG_DEBUG);
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	else if (verbose >= 3)
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		tep_set_loglevel(TEP_LOG_ALL);
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#endif
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	return 0;
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}
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int perf_quiet_option(void)
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{
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	struct sublevel_option *opt = &debug_opts[0];
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	/* disable all debug messages */
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	while (opt->name) {
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		*opt->value_ptr = -1;
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		opt++;
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	}
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	/* For debug variables that are used as bool types, set to 0. */
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	redirect_to_stderr = 0;
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	debug_peo_args = 0;
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	debug_kmaps = 0;
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	debug_type_profile = 0;
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	return 0;
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}
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#define DEBUG_WRAPPER(__n, __l)				\
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static int pr_ ## __n ## _wrapper(const char *fmt, ...)	\
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{							\
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	va_list args;					\
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	int ret;					\
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							\
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	va_start(args, fmt);				\
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	ret = veprintf(__l, verbose, fmt, args);	\
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	va_end(args);					\
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	return ret;					\
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}
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DEBUG_WRAPPER(warning, 0);
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DEBUG_WRAPPER(debug, 1);
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void perf_debug_setup(void)
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{
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	debug_set_file(stderr);
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	libapi_set_print(pr_warning_wrapper, pr_warning_wrapper, pr_debug_wrapper);
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}
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/* Obtain a backtrace and print it to stdout. */
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#ifdef HAVE_BACKTRACE_SUPPORT
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void dump_stack(void)
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{
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	void *array[16];
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	size_t size = backtrace(array, ARRAY_SIZE(array));
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	char **strings = backtrace_symbols(array, size);
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	size_t i;
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	printf("Obtained %zd stack frames.\n", size);
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	for (i = 0; i < size; i++)
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		printf("%s\n", strings[i]);
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	free(strings);
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}
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#else
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void dump_stack(void) {}
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#endif
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void sighandler_dump_stack(int sig)
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{
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	psignal(sig, "perf");
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	dump_stack();
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	signal(sig, SIG_DFL);
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	raise(sig);
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}
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