[PATCH v5 6/8] perf tests: Use scandirat for shell script finding

Ian Rogers
2024-02-16T23:55:27Z

Avoid filename appending buffers by using openat, faccessat and
scandirat more widely. Turn the script's path back to a file name
using readlink from /proc/<pid>/fd/<fd>.

Read the script's description using api/io.h to avoid fdopen
conversions. Whilst reading perform additional sanity checks on the
script's contents.

Signed-off-by: Ian Rogers <irogers@google.com>
---
tools/perf/tests/builtin-test.c | 20 ++---
tools/perf/tests/tests-scripts.c | 144 ++++++++++++++++++-------------
tools/perf/tests/tests-scripts.h | 1 -
3 files changed, 94 insertions(+), 71 deletions(-)

diff --git a/tools/perf/tests/builtin-test.c b/tools/perf/tests/builtin-test.c
index eff3c62e9b47..162f9eb090ac 100644
--- a/tools/perf/tests/builtin-test.c
+++ b/tools/perf/tests/builtin-test.c
@@ -300,22 +300,19 @@ static int test_and_print(struct test_suite *t, int subtest)
}

struct shell_test {
- const char *dir;
const char *file;
};

static int shell_test__run(struct test_suite *test, int subdir __maybe_unused)
{
int err;
- char script[PATH_MAX];
struct shell_test *st = test->priv;
+ char *cmd = NULL;

- path__join(script, sizeof(script) - 3, st->dir, st->file);
-
- if (verbose > 0)
- strncat(script, " -v", sizeof(script) - strlen(script) - 1);
-
- err = system(script);
+ if (asprintf(&cmd, "%s%s", st->file, verbose ? " -v" : "") < 0)
+ return TEST_FAIL;
+ err = system(cmd);
+ free(cmd);
if (!err)
return TEST_OK;

@@ -331,7 +328,7 @@ static int run_shell_tests(int argc, const char *argv[], int i, int width,
files = list_script_files();
if (!files)
return 0;
- for (file = files; file->dir; file++) {
+ for (file = files; file->file; file++) {
int curr = i++;
struct test_case test_cases[] = {
{
@@ -345,13 +342,12 @@ static int run_shell_tests(int argc, const char *argv[], int i, int width,
.test_cases = test_cases,
.priv = &st,
};
- st.dir = file->dir;
+ st.file = file->file;

if (test_suite.desc == NULL ||
!perf_test__matches(test_suite.desc, curr, argc, argv))
continue;

- st.file = file->file;
pr_info("%3d: %-*s:", i, width, test_suite.desc);

if (intlist__find(skiplist, i)) {
@@ -455,7 +451,7 @@ static int perf_test__list_shell(int argc, const char **argv, int i)
files = list_script_files();
if (!files)
return 0;
- for (file = files; file->dir; file++) {
+ for (file = files; file->file; file++) {
int curr = i++;
struct test_suite t = {
.desc = file->desc
diff --git a/tools/perf/tests/tests-scripts.c b/tools/perf/tests/tests-scripts.c
index 4ebd841da05b..9b3b66dd5508 100644
--- a/tools/perf/tests/tests-scripts.c
+++ b/tools/perf/tests/tests-scripts.c
@@ -14,6 +14,7 @@
#include <subcmd/parse-options.h>
#include <sys/wait.h>
#include <sys/stat.h>
+#include <api/io.h>
#include "builtin.h"
#include "tests-scripts.h"
#include "color.h"
@@ -35,55 +36,69 @@ static size_t files_num = 0;
static struct script_file *files = NULL;
static int files_max_width = 0;

-static const char *shell_tests__dir(char *path, size_t size)
+static int shell_tests__dir_fd(void)
{
- const char *devel_dirs[] = { "./tools/perf/tests", "./tests", };
- char *exec_path;
- unsigned int i;
+ char path[PATH_MAX], *exec_path;
+ static const char * const devel_dirs[] = { "./tools/perf/tests/shell", "./tests/shell", };

- for (i = 0; i < ARRAY_SIZE(devel_dirs); ++i) {
- struct stat st;
+ for (size_t i = 0; i < ARRAY_SIZE(devel_dirs); ++i) {
+ int fd = open(devel_dirs[i], O_PATH);

- if (!lstat(devel_dirs[i], &st)) {
- scnprintf(path, size, "%s/shell", devel_dirs[i]);
- if (!lstat(devel_dirs[i], &st))
- return path;
- }
+ if (fd >= 0)
+ return fd;
}

/* Then installed path. */
exec_path = get_argv_exec_path();
- scnprintf(path, size, "%s/tests/shell", exec_path);
+ scnprintf(path, sizeof(path), "%s/tests/shell", exec_path);
free(exec_path);
- return path;
+ return open(path, O_PATH);
}

-static const char *shell_test__description(char *description, size_t size,
- const char *path, const char *name)
+static char *shell_test__description(int dir_fd, const char *name)
{
- FILE *fp;
- char filename[PATH_MAX];
- int ch;
+ struct io io;
+ char buf[128], desc[256];
+ int ch, pos = 0;

- path__join(filename, sizeof(filename), path, name);
- fp = fopen(filename, "r");
- if (!fp)
+ io__init(&io, openat(dir_fd, name, O_RDONLY), buf, sizeof(buf));
+ if (io.fd < 0)
return NULL;

/* Skip first line - should be #!/bin/sh Shebang */
+ if (io__get_char(&io) != '#')
+ goto err_out;
+ if (io__get_char(&io) != '!')
+ goto err_out;
do {
- ch = fgetc(fp);
- } while (ch != EOF && ch != '\n');
-
- description = fgets(description, size, fp);
- fclose(fp);
+ ch = io__get_char(&io);
+ if (ch < 0)
+ goto err_out;
+ } while (ch != '\n');

- /* Assume first char on line is omment everything after that desc */
- return description ? strim(description + 1) : NULL;
+ do {
+ ch = io__get_char(&io);
+ if (ch < 0)
+ goto err_out;
+ } while (ch == '#' || isspace(ch));
+ while (ch > 0 && ch != '\n') {
+ desc[pos++] = ch;
+ if (pos >= (int)sizeof(desc) - 1)
+ break;
+ ch = io__get_char(&io);
+ }
+ while (pos > 0 && isspace(desc[--pos]))
+ ;
+ desc[++pos] = '\0';
+ close(io.fd);
+ return strdup(desc);
+err_out:
+ close(io.fd);
+ return NULL;
}

/* Is this full file path a shell script */
-static bool is_shell_script(const char *path)
+static bool is_shell_script(int dir_fd, const char *path)
{
const char *ext;

@@ -91,20 +106,16 @@ static bool is_shell_script(const char *path)
if (!ext)
return false;
if (!strcmp(ext, ".sh")) { /* Has .sh extension */
- if (access(path, R_OK | X_OK) == 0) /* Is executable */
+ if (faccessat(dir_fd, path, R_OK | X_OK, 0) == 0) /* Is executable */
return true;
}
return false;
}

/* Is this file in this dir a shell script (for test purposes) */
-static bool is_test_script(const char *path, const char *name)
+static bool is_test_script(int dir_fd, const char *name)
{
- char filename[PATH_MAX];
-
- path__join(filename, sizeof(filename), path, name);
- if (!is_shell_script(filename)) return false;
- return true;
+ return is_shell_script(dir_fd, name);
}

/* Duplicate a string and fall over and die if we run out of memory */
@@ -120,12 +131,21 @@ static char *strdup_check(const char *str)
return newstr;
}

-static void append_script(const char *dir, const char *file, const char *desc)
+static void append_script(int dir_fd, const char *name, char *desc)
{
+ char filename[PATH_MAX], link[128];
struct script_file *files_tmp;
- size_t files_num_tmp;
+ size_t files_num_tmp, len;
int width;

+ snprintf(link, sizeof(link), "/proc/%d/fd/%d", getpid(), dir_fd);
+ len = readlink(link, filename, sizeof(filename));
+ if (len < 0) {
+ pr_err("Failed to readlink %s", link);
+ return;
+ }
+ filename[len++] = '/';
+ strcpy(&filename[len], name);
files_num_tmp = files_num + 1;
if (files_num_tmp >= SIZE_MAX) {
pr_err("Too many script files\n");
@@ -142,10 +162,8 @@ static void append_script(const char *dir, const char *file, const char *desc)
/* Add file to end and NULL terminate the struct array */
files = files_tmp;
files_num = files_num_tmp;
- files[files_num - 1].dir = strdup_check(dir);
- files[files_num - 1].file = strdup_check(file);
- files[files_num - 1].desc = strdup_check(desc);
- files[files_num].dir = NULL;
+ files[files_num - 1].file = strdup_check(filename);
+ files[files_num - 1].desc = desc;
files[files_num].file = NULL;
files[files_num].desc = NULL;

@@ -154,32 +172,39 @@ static void append_script(const char *dir, const char *file, const char *desc)
files_max_width = width;
}

-static void append_scripts_in_dir(const char *path)
+static void append_scripts_in_dir(int dir_fd)
{
struct dirent **entlist;
struct dirent *ent;
int n_dirs, i;
- char filename[PATH_MAX];

/* List files, sorted by alpha */
- n_dirs = scandir(path, &entlist, NULL, alphasort);
+ n_dirs = scandirat(dir_fd, ".", &entlist, NULL, alphasort);
if (n_dirs == -1)
return;
for (i = 0; i < n_dirs && (ent = entlist[i]); i++) {
+ int fd;
+
if (ent->d_name[0] == '.')
continue; /* Skip hidden files */
- if (is_test_script(path, ent->d_name)) { /* It's a test */
- char bf[256];
- const char *desc = shell_test__description
- (bf, sizeof(bf), path, ent->d_name);
+ if (is_test_script(dir_fd, ent->d_name)) { /* It's a test */
+ char *desc = shell_test__description(dir_fd, ent->d_name);

if (desc) /* It has a desc line - valid script */
- append_script(path, ent->d_name, desc);
- } else if (is_directory(path, ent)) { /* Scan the subdir */
- path__join(filename, sizeof(filename),
- path, ent->d_name);
- append_scripts_in_dir(filename);
+ append_script(dir_fd, ent->d_name, desc);
+ continue;
+ }
+ if (ent->d_type != DT_DIR) {
+ struct stat st;
+
+ if (ent->d_type != DT_UNKNOWN)
+ continue;
+ fstatat(dir_fd, ent->d_name, &st, 0);
+ if (!S_ISDIR(st.st_mode))
+ continue;
}
+ fd = openat(dir_fd, ent->d_name, O_PATH);
+ append_scripts_in_dir(fd);
}
for (i = 0; i < n_dirs; i++) /* Clean up */
zfree(&entlist[i]);
@@ -188,14 +213,17 @@ static void append_scripts_in_dir(const char *path)

const struct script_file *list_script_files(void)
{
- char path_dir[PATH_MAX];
- const char *path;
+ int dir_fd;

if (files)
return files; /* Singleton - we already know our list */

- path = shell_tests__dir(path_dir, sizeof(path_dir)); /* Walk dir */
- append_scripts_in_dir(path);
+ dir_fd = shell_tests__dir_fd(); /* Walk dir */
+ if (dir_fd < 0)
+ return NULL;
+
+ append_scripts_in_dir(dir_fd);
+ close(dir_fd);

return files;
}
diff --git a/tools/perf/tests/tests-scripts.h b/tools/perf/tests/tests-scripts.h
index 3a3ec6191848..3508a293aaf9 100644
--- a/tools/perf/tests/tests-scripts.h
+++ b/tools/perf/tests/tests-scripts.h
@@ -3,7 +3,6 @@
#define TESTS_SCRIPTS_H

struct script_file {
- char *dir;
char *file;
char *desc;
};
--
2.44.0.rc0.258.g7320e95886-goog