From 3d549ee3749049d41e9e530ca98016f2c215e8db Mon Sep 17 00:00:00 2001 From: Bhavik Sachdev Date: Mon, 26 Aug 2024 20:56:14 +0530 Subject: [PATCH] zdtm: Check pidfd for thread is valid after C/R We open a pidfd to a thread using `PIDFD_THREAD` flag and after C/R ensure that we can send signals using it with `PIDFD_SIGNAL_THREAD`. signed-off-by: Bhavik Sachdev --- test/zdtm/static/Makefile | 1 + test/zdtm/static/pidfd_of_thread.c | 114 ++++++++++++++++++++++++++ test/zdtm/static/pidfd_of_thread.desc | 1 + 3 files changed, 116 insertions(+) create mode 100644 test/zdtm/static/pidfd_of_thread.c create mode 100644 test/zdtm/static/pidfd_of_thread.desc diff --git a/test/zdtm/static/Makefile b/test/zdtm/static/Makefile index f4dbb1d96a..44ac64fe57 100644 --- a/test/zdtm/static/Makefile +++ b/test/zdtm/static/Makefile @@ -54,6 +54,7 @@ TST_NOFILE := \ shm-mp \ ptrace_sig \ pidfd_self \ + pidfd_of_thread \ pidfd_dead \ pidfd_child \ pidfd_kill \ diff --git a/test/zdtm/static/pidfd_of_thread.c b/test/zdtm/static/pidfd_of_thread.c new file mode 100644 index 0000000000..0a2269b66d --- /dev/null +++ b/test/zdtm/static/pidfd_of_thread.c @@ -0,0 +1,114 @@ +#include +#include +#include +#include + +#include "zdtmtst.h" +#include "lock.h" + +const char *test_doc = "Check C/R of pidfds that point to threads\n"; +const char *test_author = "Bhavik Sachdev "; + +/* see also: https://codebrowser.dev/glibc/glibc/sysdeps/unix/sysv/linux/tst-clone3.c.html */ + +#ifndef PIDFD_THREAD +#define PIDFD_THREAD O_EXCL +#endif + +#ifndef PIDFD_SIGNAL_THREAD +#define PIDFD_SIGNAL_THREAD (1UL << 0) +#endif + +#ifndef PID_FS_MAGIC +#define PID_FS_MAGIC 0x50494446 +#endif + +static long get_fs_type(int lfd) +{ + struct statfs fst; + + if (fstatfs(lfd, &fst)) { + return -1; + } + return fst.f_type; +} + +static int pidfd_open(pid_t pid, unsigned int flags) +{ + return syscall(__NR_pidfd_open, pid, flags); +} + +static int pidfd_send_signal(int pidfd, int sig, siginfo_t* info, unsigned int flags) +{ + return syscall(__NR_pidfd_send_signal, pidfd, sig, info, flags); +} + +static int thread_func(void *a) +{ + test_waitsig(); + return 0; +} + +#define CTID_INIT_VAL 1 + +int main(int argc, char* argv[]) +{ + char st[64 * 1024] __attribute__ ((aligned)); + pid_t tid; + int pidfd, test_pidfd; + futex_t exited; + + int clone_flags = CLONE_THREAD; + clone_flags |= CLONE_VM | CLONE_SIGHAND; + clone_flags |= CLONE_CHILD_CLEARTID; + + test_init(argc, argv); + + test_pidfd = pidfd_open(getpid(), 0); + if (test_pidfd < 0) { + pr_perror("pidfd_open() failed"); + return 1; + } + + /* PIDFD_THREAD, PIDFD_SIGNAL_THREAD are supported only with pidfs */ + if (get_fs_type(test_pidfd) != PID_FS_MAGIC) { + test_daemon(); + test_waitsig(); + fail("skipping as pidfs not supported."); + close(test_pidfd); + return 0; + } + close(test_pidfd); + + futex_set(&exited, CTID_INIT_VAL); + + tid = clone(thread_func, st + sizeof(st), clone_flags, NULL, NULL, NULL, &(exited.raw)); + if (tid == -1) { + pr_perror("clone() failed"); + return 1; + } + + test_msg("Successfully created a thread with tid: %d\n", tid); + pidfd = pidfd_open(tid, PIDFD_THREAD); + if (pidfd < 0) { + pr_perror("pidfd_open() failed"); + return 1; + } + + test_daemon(); + test_waitsig(); + + if (pidfd_send_signal(pidfd, SIGTERM, NULL, PIDFD_SIGNAL_THREAD)) { + pr_perror("pidfd_send_signal() failed"); + fail(); + close(pidfd); + return 1; + } + + test_msg("Waiting for thread to exit\n"); + futex_wait_until(&exited, 0); + + pass(); + close(pidfd); + return 0; +} diff --git a/test/zdtm/static/pidfd_of_thread.desc b/test/zdtm/static/pidfd_of_thread.desc new file mode 100644 index 0000000000..ded89879a9 --- /dev/null +++ b/test/zdtm/static/pidfd_of_thread.desc @@ -0,0 +1 @@ +{'flags': 'crfail'}