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

Namhyung Kim
2024-02-21T01:54:49Z

On Fri, Feb 16, 2024 at 3:55 PM Ian Rogers <irogers@google.com> wrote:
>
> 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>

Ditto.

tests/tests-scripts.c: In function 'append_scripts_in_dir':
tests/tests-scripts.c:200:18: error: implicit declaration of
function 'scandirat'; did you mean 'scandir'?
[-Werror=implicit-function-declaration]
200 | n_dirs = scandirat(dir_fd, ".", &entlist, NULL,
alphasort);
| ^~~~~~~~~
| scandir

Thanks,
Namhyung

> ---
> 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
>