Commit 370ce164 authored by Ian Rogers's avatar Ian Rogers Committed by Arnaldo Carvalho de Melo
Browse files

perf path: Make mkpath thread safe, remove 16384 bytes from .bss 



Avoid 4 static arrays for paths, pass in a char[] buffer to use. Makes
mkpath thread safe for the small number of users. Also removes 16,384
bytes from .bss.

Signed-off-by: default avatarIan Rogers <irogers@google.com>
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: K Prateek Nayak <kprateek.nayak@amd.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ravi Bangoria <ravi.bangoria@amd.com>
Cc: Ross Zwisler <zwisler@chromium.org>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Tiezhu Yang <yangtiezhu@loongson.cn>
Cc: Yang Jihong <yangjihong1@huawei.com>
Link: https://lore.kernel.org/r/20230526183401.2326121-13-irogers@google.com


Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
parent 430952e6

tools/perf/builtin-config.c

+3 −1
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include "util/debug.h"

#include "util/config.h"

#include <linux/string.h>

#include <limits.h>

#include <stdio.h>

#include <stdlib.h>
@@ -157,7 +158,8 @@ int cmd_config(int argc, const char **argv) 
{

	int i, ret = -1;

	struct perf_config_set *set;

	char *user_config = mkpath("%s/.perfconfig", getenv("HOME"));

	char path[PATH_MAX];

	char *user_config = mkpath(path, sizeof(path), "%s/.perfconfig", getenv("HOME"));

	const char *config_filename;

	bool changed = false;

tools/perf/builtin-help.c

+3 −1
Original line number Diff line number Diff line
@@ -19,6 +19,7 @@ 
#include <linux/string.h>

#include <linux/zalloc.h>

#include <errno.h>

#include <limits.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>
@@ -389,9 +390,10 @@ static int get_html_page_path(char **page_path, const char *page) 
{

	struct stat st;

	const char *html_path = system_path(PERF_HTML_PATH);

	char path[PATH_MAX];



	/* Check that we have a perf documentation directory. */

	if (stat(mkpath("%s/perf.html", html_path), &st)

	if (stat(mkpath(path, sizeof(path), "%s/perf.html", html_path), &st)

	    || !S_ISREG(st.st_mode)) {

		pr_err("'%s': not a documentation directory.", html_path);

		return -1;

tools/perf/util/cache.h

+1 −1
Original line number Diff line number Diff line
@@ -26,6 +26,6 @@ static inline int is_absolute_path(const char *path) 
	return path[0] == '/';

}



char *mkpath(const char *fmt, ...) __printf(1, 2);

char *mkpath(char *path_buf, size_t sz, const char *fmt, ...) __printf(3, 4);



#endif /* __PERF_CACHE_H */

tools/perf/util/config.c

+2 −1
Original line number Diff line number Diff line
@@ -543,6 +543,7 @@ static char *home_perfconfig(void) 
	const char *home = NULL;

	char *config;

	struct stat st;

	char path[PATH_MAX];



	home = getenv("HOME");
@@ -554,7 +555,7 @@ static char *home_perfconfig(void) 
	if (!home || !*home || !perf_config_global())

		return NULL;



	config = strdup(mkpath("%s/.perfconfig", home));

	config = strdup(mkpath(path, sizeof(path), "%s/.perfconfig", home));

	if (config == NULL) {

		pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.\n", home);

		return NULL;

tools/perf/util/path.c

+5 −30
Original line number Diff line number Diff line 
// SPDX-License-Identifier: GPL-2.0

/*

 * I'm tired of doing "vsnprintf()" etc just to open a

 * file, so here's a "return static buffer with printf"

 * interface for paths.

 *

 * It's obviously not thread-safe. Sue me. But it's quite

 * useful for doing things like

 *

 *   f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);

 *

 * which is what it's designed for.

 */

#include "path.h"

#include "cache.h"

#include <linux/kernel.h>
@@ -22,18 +10,6 @@ 
#include <dirent.h>

#include <unistd.h>



static char bad_path[] = "/bad-path/";

/*

 * One hack:

 */

static char *get_pathname(void)

{

	static char pathname_array[4][PATH_MAX];

	static int idx;



	return pathname_array[3 & ++idx];

}



static char *cleanup_path(char *path)

{

	/* Clean it up */
@@ -45,18 +21,17 @@ static char *cleanup_path(char *path) 
	return path;

}



char *mkpath(const char *fmt, ...)

char *mkpath(char *path_buf, size_t sz, const char *fmt, ...)

{

	va_list args;

	unsigned len;

	char *pathname = get_pathname();



	va_start(args, fmt);

	len = vsnprintf(pathname, PATH_MAX, fmt, args);

	len = vsnprintf(path_buf, sz, fmt, args);

	va_end(args);

	if (len >= PATH_MAX)

		return bad_path;

	return cleanup_path(pathname);

	if (len >= sz)

		strncpy(path_buf, "/bad-path/", sz);

	return cleanup_path(path_buf);

}



int path__join(char *bf, size_t size, const char *path1, const char *path2)