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

Ian Rogers
2024-02-21T03:41:47Z

On Tue, Feb 20, 2024 at 5:54 PM Namhyung Kim <namhyung@kernel.org> wrote:
>
> 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

Sorry, missed the workaround definition in util.h. Will fix in v6.

Thanks,
Ian

> 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
> >