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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-27 10:05:51 +0000 |
commit | 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 (patch) | |
tree | a94efe259b9009378be6d90eb30d2b019d95c194 /tools/testing/selftests/proc/read.c | |
parent | Initial commit. (diff) | |
download | linux-upstream.tar.xz linux-upstream.zip |
Adding upstream version 5.10.209.upstream/5.10.209upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'tools/testing/selftests/proc/read.c')
-rw-r--r-- | tools/testing/selftests/proc/read.c | 146 |
1 files changed, 146 insertions, 0 deletions
diff --git a/tools/testing/selftests/proc/read.c b/tools/testing/selftests/proc/read.c new file mode 100644 index 000000000..b3ef9e14d --- /dev/null +++ b/tools/testing/selftests/proc/read.c @@ -0,0 +1,146 @@ +/* + * Copyright © 2018 Alexey Dobriyan <adobriyan@gmail.com> + * + * 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 <stdio.h> +#include <string.h> +#include <sys/stat.h> +#include <sys/vfs.h> +#include <fcntl.h> +#include <unistd.h> + +#include "proc.h" + +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; + struct statfs sfs; + + d = opendir("/proc"); + if (!d) + return 4; + + /* Ensure /proc is proc. */ + if (fstatfs(dirfd(d), &sfs) == -1) { + return 1; + } + if (sfs.f_type != 0x9fa0) { + fprintf(stderr, "error: unexpected f_type %lx\n", (long)sfs.f_type); + return 2; + } + + f(d, 0); + + return 0; +} |