Date: Mon, 08 Jun 2026 22:50:05 +0000 From: Mark Johnston <markj@FreeBSD.org> To: src-committers@FreeBSD.org, dev-commits-src-all@FreeBSD.org, dev-commits-src-main@FreeBSD.org Subject: git: 6cd8a1bf4f15 - main - tests/ptrace: Validate PT_SC_REMOTE with some tricky syscalls Message-ID: <6a27471d.243f4.4559ed13@gitrepo.freebsd.org>
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The branch main has been updated by markj: URL: https://cgit.FreeBSD.org/src/commit/?id=6cd8a1bf4f15ff8a9b646dc94ac90b3fe0926650 commit 6cd8a1bf4f15ff8a9b646dc94ac90b3fe0926650 Author: Mark Johnston <markj@FreeBSD.org> AuthorDate: 2026-06-08 22:45:54 +0000 Commit: Mark Johnston <markj@FreeBSD.org> CommitDate: 2026-06-08 22:49:51 +0000 tests/ptrace: Validate PT_SC_REMOTE with some tricky syscalls Reviewed by: kib MFC after: 2 weeks Differential Revision: https://reviews.freebsd.org/D57485 --- tests/sys/kern/ptrace_test.c | 215 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 215 insertions(+) diff --git a/tests/sys/kern/ptrace_test.c b/tests/sys/kern/ptrace_test.c index 3a55a6f48033..478e787d129b 100644 --- a/tests/sys/kern/ptrace_test.c +++ b/tests/sys/kern/ptrace_test.c @@ -26,6 +26,8 @@ #include <sys/types.h> #include <sys/cpuset.h> #include <sys/elf.h> +#define _WANT_KERNEL_ERRNO +#include <sys/errno.h> #include <sys/event.h> #include <sys/file.h> #include <sys/mman.h> @@ -4472,6 +4474,215 @@ ATF_TC_BODY(ptrace__PT_SC_REMOTE_syscall_validation, tc) ATF_REQUIRE(ptrace(PT_DETACH, fpid, (caddr_t)1, 0) != -1); } +ATF_TC_WITHOUT_HEAD(ptrace__PT_SC_REMOTE_exit); +ATF_TC_BODY(ptrace__PT_SC_REMOTE_exit, tc) +{ + struct ptrace_sc_remote pscr; + syscallarg_t args[1]; + pid_t fpid, wpid; + int status; + + ATF_REQUIRE((fpid = fork()) != -1); + if (fpid == 0) { + trace_me(); + exit(0); + } + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + REQUIRE_EQ(WSTOPSIG(status), SIGSTOP); + + args[0] = 42; + pscr.pscr_syscall = SYS_exit; + pscr.pscr_nargs = 1; + pscr.pscr_args = args; + ATF_REQUIRE(ptrace(PT_SC_REMOTE, fpid, (caddr_t)&pscr, + sizeof(pscr)) != -1); + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, 0) != -1); + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFEXITED(status)); + REQUIRE_EQ(WEXITSTATUS(status), 42); +} + +/* + * Trace a forking process with FOLLOW_FORK. Once the child stops in + * fork_return(), use PT_SC_REMOTE to force it to call exit(). + */ +ATF_TC_WITHOUT_HEAD(ptrace__PT_SC_REMOTE_exit_child); +ATF_TC_BODY(ptrace__PT_SC_REMOTE_exit_child, tc) +{ + struct ptrace_sc_remote pscr; + syscallarg_t args[1]; + pid_t child, fpid, wpid; + int status; + + ATF_REQUIRE((fpid = fork()) != -1); + if (fpid == 0) { + trace_me(); + follow_fork_parent(false); + } + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + REQUIRE_EQ(WSTOPSIG(status), SIGSTOP); + + ATF_REQUIRE(ptrace(PT_LWP_EVENTS, fpid, NULL, 1) != -1); + ATF_REQUIRE(ptrace(PT_FOLLOW_FORK, fpid, NULL, 1) != -1); + ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, 0) != -1); + + child = handle_fork_events(fpid, NULL); + ATF_REQUIRE(child > 0); + + args[0] = 42; + pscr.pscr_syscall = SYS_exit; + pscr.pscr_nargs = 1; + pscr.pscr_args = args; + + /* The child must be at the syscall boundary. */ + ATF_REQUIRE_ERRNO(EBUSY, + ptrace(PT_SC_REMOTE, child, (caddr_t)&pscr, sizeof(pscr)) == -1); + + /* Resume the child and ask it to stop during syscall exits. */ + ATF_REQUIRE(ptrace(PT_TO_SCX, child, (caddr_t)1, 0) != -1); + + wpid = waitpid(child, &status, 0); + REQUIRE_EQ(wpid, child); + ATF_REQUIRE(WIFSTOPPED(status)); + + ATF_REQUIRE(ptrace(PT_SC_REMOTE, child, (caddr_t)&pscr, sizeof(pscr)) != + -1); + + wpid = waitpid(child, &status, 0); + REQUIRE_EQ(wpid, child); + ATF_REQUIRE(WIFSTOPPED(status)); + ATF_REQUIRE(ptrace(PT_CONTINUE, child, (caddr_t)1, 0) != -1); + + wpid = waitpid(child, &status, 0); + REQUIRE_EQ(wpid, child); + ATF_REQUIRE(WIFEXITED(status)); + REQUIRE_EQ(WEXITSTATUS(status), 42); +} + +/* + * Use PT_SC_REMOTE to ask the tracee to exit, then send SIGKILL before + * continuing it. + */ +ATF_TC_WITHOUT_HEAD(ptrace__PT_SC_REMOTE_exit_sigkill); +ATF_TC_BODY(ptrace__PT_SC_REMOTE_exit_sigkill, tc) +{ + struct ptrace_sc_remote pscr; + syscallarg_t args[1]; + pid_t fpid, wpid; + int status; + + ATF_REQUIRE((fpid = fork()) != -1); + if (fpid == 0) { + trace_me(); + exit(0); + } + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + REQUIRE_EQ(WSTOPSIG(status), SIGSTOP); + + args[0] = 42; + pscr.pscr_syscall = SYS_exit; + pscr.pscr_nargs = 1; + pscr.pscr_args = args; + ATF_REQUIRE(ptrace(PT_SC_REMOTE, fpid, (caddr_t)&pscr, + sizeof(pscr)) != -1); + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + + ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, SIGKILL) != -1); + + /* The child should honour the original exit() call. */ + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFEXITED(status)); + REQUIRE_EQ(WEXITSTATUS(status), 42); +} + +ATF_TC_WITHOUT_HEAD(ptrace__PT_SC_REMOTE_execve); +ATF_TC_BODY(ptrace__PT_SC_REMOTE_execve, tc) +{ + struct ptrace_sc_remote pscr; + syscallarg_t args[3]; + char *ping_path; + char *argv[5]; + char *envp[1]; + pid_t fpid, wpid; + int status; + + ping_path = __DECONST(char *, "/sbin/ping"); + argv[0] = ping_path; + argv[1] = __DECONST(char *, "-c"); + argv[2] = __DECONST(char *, "1"); + argv[3] = __DECONST(char *, "localhost"); + argv[4] = NULL; + envp[0] = NULL; + + ATF_REQUIRE((fpid = fork()) != -1); + if (fpid == 0) { + trace_me(); + exit(0); + } + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + REQUIRE_EQ(WSTOPSIG(status), SIGSTOP); + + args[0] = (syscallarg_t)ping_path; + args[1] = (syscallarg_t)argv; + args[2] = (syscallarg_t)envp; + pscr.pscr_syscall = SYS_execve; + pscr.pscr_nargs = 3; + pscr.pscr_args = args; + ATF_REQUIRE(ptrace(PT_SC_REMOTE, fpid, (caddr_t)&pscr, + sizeof(pscr)) != -1); + /* EJUSTRETURN here is an implementation detail. */ + REQUIRE_EQ(pscr.pscr_ret.sr_error, EJUSTRETURN); + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + REQUIRE_EQ(WSTOPSIG(status), SIGSTOP); + + { + struct kinfo_proc kp; + size_t len; + int mib[4]; + + mib[0] = CTL_KERN; + mib[1] = KERN_PROC; + mib[2] = KERN_PROC_PID; + mib[3] = fpid; + len = sizeof(kp); + ATF_REQUIRE(sysctl(mib, nitems(mib), &kp, &len, NULL, 0) == 0); + ATF_REQUIRE_STREQ(kp.ki_comm, "ping"); + } + + /* Let the child (now ping) run to completion. */ + ATF_REQUIRE(ptrace(PT_DETACH, fpid, (caddr_t)1, 0) != -1); + + wpid = waitpid(fpid, &status, 0); + REQUIRE_EQ(wpid, fpid); + ATF_REQUIRE(WIFEXITED(status)); + REQUIRE_EQ(WEXITSTATUS(status), 0); +} + /* * Ensure that procctl(PROC_REAP_KILL) won't block forever waiting for a target * process that stopped to report its status to a debugger. @@ -4712,6 +4923,10 @@ ATF_TP_ADD_TCS(tp) ATF_TP_ADD_TC(tp, ptrace__procdesc_reparent_wait_child); ATF_TP_ADD_TC(tp, ptrace__PT_SC_REMOTE_getpid); ATF_TP_ADD_TC(tp, ptrace__PT_SC_REMOTE_syscall_validation); + ATF_TP_ADD_TC(tp, ptrace__PT_SC_REMOTE_exit); + ATF_TP_ADD_TC(tp, ptrace__PT_SC_REMOTE_exit_child); + ATF_TP_ADD_TC(tp, ptrace__PT_SC_REMOTE_exit_sigkill); + ATF_TP_ADD_TC(tp, ptrace__PT_SC_REMOTE_execve); ATF_TP_ADD_TC(tp, ptrace__reap_kill_stopped); ATF_TP_ADD_TC(tp, ptrace__PT_ATTACH_no_EINTR); ATF_TP_ADD_TC(tp, ptrace__PT_DETACH_continued);home | help
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