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	To make it portable to non-glibc systems, that follow the XSI variant instead of the GNU specific one that gets in place when _GNU_SOURCE is defined. Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Wang Nan <wangnan0@huawei.com> Link: http://lkml.kernel.org/n/tip-mixgnh3iyajuqogn2opsocdy@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
		
			
				
	
	
		
			136 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			136 lines
		
	
	
	
		
			2.9 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#ifndef _GNU_SOURCE
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# define _GNU_SOURCE
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#endif
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#include <stdio.h>
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#include <stdlib.h>
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#include <string.h>
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#include <linux/string.h>
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#include <errno.h>
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#include <unistd.h>
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#include "fs.h"
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#include "tracing_path.h"
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char tracing_mnt[PATH_MAX]         = "/sys/kernel/debug";
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char tracing_path[PATH_MAX]        = "/sys/kernel/debug/tracing";
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char tracing_events_path[PATH_MAX] = "/sys/kernel/debug/tracing/events";
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static void __tracing_path_set(const char *tracing, const char *mountpoint)
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{
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	snprintf(tracing_mnt, sizeof(tracing_mnt), "%s", mountpoint);
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	snprintf(tracing_path, sizeof(tracing_path), "%s/%s",
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		 mountpoint, tracing);
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	snprintf(tracing_events_path, sizeof(tracing_events_path), "%s/%s%s",
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		 mountpoint, tracing, "events");
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}
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static const char *tracing_path_tracefs_mount(void)
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{
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	const char *mnt;
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	mnt = tracefs__mount();
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	if (!mnt)
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		return NULL;
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	__tracing_path_set("", mnt);
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	return mnt;
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}
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static const char *tracing_path_debugfs_mount(void)
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{
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	const char *mnt;
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	mnt = debugfs__mount();
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	if (!mnt)
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		return NULL;
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	__tracing_path_set("tracing/", mnt);
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	return mnt;
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}
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const char *tracing_path_mount(void)
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{
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	const char *mnt;
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	mnt = tracing_path_tracefs_mount();
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	if (mnt)
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		return mnt;
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	mnt = tracing_path_debugfs_mount();
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	return mnt;
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}
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void tracing_path_set(const char *mntpt)
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{
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	__tracing_path_set("tracing/", mntpt);
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}
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char *get_tracing_file(const char *name)
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{
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	char *file;
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	if (asprintf(&file, "%s/%s", tracing_path, name) < 0)
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		return NULL;
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	return file;
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}
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void put_tracing_file(char *file)
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{
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	free(file);
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}
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static int strerror_open(int err, char *buf, size_t size, const char *filename)
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{
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	char sbuf[128];
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	switch (err) {
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	case ENOENT:
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		/*
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		 * We will get here if we can't find the tracepoint, but one of
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		 * debugfs or tracefs is configured, which means you probably
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		 * want some tracepoint which wasn't compiled in your kernel.
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		 * - jirka
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		 */
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		if (debugfs__configured() || tracefs__configured()) {
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			snprintf(buf, size,
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				 "Error:\tFile %s/%s not found.\n"
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				 "Hint:\tPerhaps this kernel misses some CONFIG_ setting to enable this feature?.\n",
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				 tracing_events_path, filename);
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			break;
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		}
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		snprintf(buf, size, "%s",
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			 "Error:\tUnable to find debugfs/tracefs\n"
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			 "Hint:\tWas your kernel compiled with debugfs/tracefs support?\n"
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			 "Hint:\tIs the debugfs/tracefs filesystem mounted?\n"
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			 "Hint:\tTry 'sudo mount -t debugfs nodev /sys/kernel/debug'");
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		break;
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	case EACCES: {
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		snprintf(buf, size,
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			 "Error:\tNo permissions to read %s/%s\n"
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			 "Hint:\tTry 'sudo mount -o remount,mode=755 %s'\n",
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			 tracing_events_path, filename, tracing_mnt);
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	}
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		break;
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	default:
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		snprintf(buf, size, "%s", str_error_r(err, sbuf, sizeof(sbuf)));
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		break;
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	}
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	return 0;
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}
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int tracing_path__strerror_open_tp(int err, char *buf, size_t size, const char *sys, const char *name)
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{
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	char path[PATH_MAX];
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	snprintf(path, PATH_MAX, "%s/%s", sys, name ?: "*");
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	return strerror_open(err, buf, size, path);
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}
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