From: Alexey Dobriyan <adobriyan@xxxxxxxxx> Subject: proc: selftests: shotgun testing of read/readdir/readlink/write Perform reads with nearly everything in /proc, and some writing as well. Hopefully memleak checkers and KASAN will find something. [adobriyan@xxxxxxxxx: /proc/kmsg can and will block if read under root] Link: http://lkml.kernel.org/r/20180316232147.GA20146@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> [adobriyan@xxxxxxxxx: /proc/sysrq-trigger lives on the ground floor] Link: http://lkml.kernel.org/r/20180317164911.GA3445@avx2 Link: http://lkml.kernel.org/r/20180315201251.GA12396@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- tools/testing/selftests/proc/.gitignore | 1 tools/testing/selftests/proc/Makefile | 1 tools/testing/selftests/proc/read.c | 147 ++++++++++++++++++++++ 3 files changed, 149 insertions(+) diff -puN tools/testing/selftests/proc/.gitignore~proc-shotgun-test-read-readdir-readlink-a-little-write tools/testing/selftests/proc/.gitignore --- a/tools/testing/selftests/proc/.gitignore~proc-shotgun-test-read-readdir-readlink-a-little-write +++ a/tools/testing/selftests/proc/.gitignore @@ -3,3 +3,4 @@ /proc-self-map-files-002 /proc-self-syscall /proc-self-wchan +/read diff -puN tools/testing/selftests/proc/Makefile~proc-shotgun-test-read-readdir-readlink-a-little-write tools/testing/selftests/proc/Makefile --- a/tools/testing/selftests/proc/Makefile~proc-shotgun-test-read-readdir-readlink-a-little-write +++ a/tools/testing/selftests/proc/Makefile @@ -6,5 +6,6 @@ TEST_GEN_PROGS += proc-self-map-files-00 TEST_GEN_PROGS += proc-self-map-files-002 TEST_GEN_PROGS += proc-self-syscall TEST_GEN_PROGS += proc-self-wchan +TEST_GEN_PROGS += read include ../lib.mk diff -puN /dev/null tools/testing/selftests/proc/read.c --- /dev/null +++ a/tools/testing/selftests/proc/read.c @@ -0,0 +1,147 @@ +/* + * Copyright _ 2018 Alexey Dobriyan <adobriyan@xxxxxxxxx> + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF + * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ +// Test +// 1) read of every file in /proc +// 2) readlink of every symlink in /proc +// 3) recursively (1) + (2) for every directory in /proc +// 4) write to /proc/*/clear_refs and /proc/*/task/*/clear_refs +// 5) write to /proc/sysrq-trigger +#undef NDEBUG +#include <assert.h> +#include <errno.h> +#include <sys/types.h> +#include <dirent.h> +#include <stdbool.h> +#include <stdlib.h> +#include <string.h> +#include <sys/stat.h> +#include <fcntl.h> +#include <unistd.h> + +static inline bool streq(const char *s1, const char *s2) +{ + return strcmp(s1, s2) == 0; +} + +static struct dirent *xreaddir(DIR *d) +{ + struct dirent *de; + + errno = 0; + de = readdir(d); + if (!de && errno != 0) { + exit(1); + } + return de; +} + +static void f_reg(DIR *d, const char *filename) +{ + char buf[4096]; + int fd; + ssize_t rv; + + /* read from /proc/kmsg can block */ + fd = openat(dirfd(d), filename, O_RDONLY|O_NONBLOCK); + if (fd == -1) + return; + rv = read(fd, buf, sizeof(buf)); + assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); + close(fd); +} + +static void f_reg_write(DIR *d, const char *filename, const char *buf, size_t len) +{ + int fd; + ssize_t rv; + + fd = openat(dirfd(d), filename, O_WRONLY); + if (fd == -1) + return; + rv = write(fd, buf, len); + assert((0 <= rv && rv <= len) || rv == -1); + close(fd); +} + +static void f_lnk(DIR *d, const char *filename) +{ + char buf[4096]; + ssize_t rv; + + rv = readlinkat(dirfd(d), filename, buf, sizeof(buf)); + assert((0 <= rv && rv <= sizeof(buf)) || rv == -1); +} + +static void f(DIR *d, unsigned int level) +{ + struct dirent *de; + + de = xreaddir(d); + assert(de->d_type == DT_DIR); + assert(streq(de->d_name, ".")); + + de = xreaddir(d); + assert(de->d_type == DT_DIR); + assert(streq(de->d_name, "..")); + + while ((de = xreaddir(d))) { + assert(!streq(de->d_name, ".")); + assert(!streq(de->d_name, "..")); + + switch (de->d_type) { + DIR *dd; + int fd; + + case DT_REG: + if (level == 0 && streq(de->d_name, "sysrq-trigger")) { + f_reg_write(d, de->d_name, "h", 1); + } else if (level == 1 && streq(de->d_name, "clear_refs")) { + f_reg_write(d, de->d_name, "1", 1); + } else if (level == 3 && streq(de->d_name, "clear_refs")) { + f_reg_write(d, de->d_name, "1", 1); + } else { + f_reg(d, de->d_name); + } + break; + case DT_DIR: + fd = openat(dirfd(d), de->d_name, O_DIRECTORY|O_RDONLY); + if (fd == -1) + continue; + dd = fdopendir(fd); + if (!dd) + continue; + f(dd, level + 1); + closedir(dd); + break; + case DT_LNK: + f_lnk(d, de->d_name); + break; + default: + assert(0); + } + } +} + +int main(void) +{ + DIR *d; + + d = opendir("/proc"); + if (!d) + return 2; + f(d, 0); + return 0; +} _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
