git: 43b4da44118e - main - ptrace tests: Add a test using PROC_REAP_KILL to kill a traced debuggee

[Mark Johnston]

The branch main has been updated by markj:

URL: 
https://cgit.FreeBSD.org/src/commit/?id=43b4da44118e4fe29e9d7456db4390c9cbb53636

commit 43b4da44118e4fe29e9d7456db4390c9cbb53636
Author:     Mark Johnston <ma...@freebsd.org>
AuthorDate: 2024-03-31 18:11:47 +0000
Commit:     Mark Johnston <ma...@freebsd.org>
CommitDate: 2024-03-31 18:11:47 +0000

    ptrace tests: Add a test using PROC_REAP_KILL to kill a traced debuggee
    
    This exercises the bug fix in commit 9241ebc796c1
    ("thread_single(9): decline external requests for traced or 
debugger-stopped procs").
    
    Reviewed by:    kib
    MFC after:      2 weeks
    Differential Revision:  https://reviews.freebsd.org/D44564
---
 tests/sys/kern/ptrace_test.c | 47 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

diff --git a/tests/sys/kern/ptrace_test.c b/tests/sys/kern/ptrace_test.c
index bd176e2963f0..b65c84144ad0 100644
--- a/tests/sys/kern/ptrace_test.c
+++ b/tests/sys/kern/ptrace_test.c
@@ -4368,6 +4368,52 @@ ATF_TC_BODY(ptrace__PT_SC_REMOTE_getpid, tc)
        ATF_REQUIRE(ptrace(PT_DETACH, fpid, (caddr_t)1, 0) != -1);
 }
 
+/*
+ * Ensure that procctl(PROC_REAP_KILL) won't block forever waiting for a target
+ * process that stopped to report its status to a debugger.
+ */
+ATF_TC_WITHOUT_HEAD(ptrace__reap_kill_stopped);
+ATF_TC_BODY(ptrace__reap_kill_stopped, tc)
+{
+       struct procctl_reaper_kill prk;
+       pid_t debuggee, wpid;
+       int error, status;
+
+       REQUIRE_EQ(procctl(P_PID, getpid(), PROC_REAP_ACQUIRE, NULL), 0);
+
+       debuggee = fork();
+       ATF_REQUIRE(debuggee >= 0);
+       if (debuggee == 0) {
+               trace_me();
+               for (;;)
+                       sleep(10);
+               _exit(0);
+       }
+       wpid = waitpid(debuggee, &status, 0);
+       REQUIRE_EQ(wpid, debuggee);
+       ATF_REQUIRE(WIFSTOPPED(status));
+       REQUIRE_EQ(WSTOPSIG(status), SIGSTOP);
+
+       /* Resume the child and ask it to stop during syscall exits. */
+       ATF_REQUIRE(ptrace(PT_TO_SCX, debuggee, (caddr_t)1, 0) != -1);
+
+       /* Give the debuggee some time to go to sleep. */
+       usleep(100000);
+
+       /*
+        * Kill the child process.  procctl() may attempt to stop the target
+        * process to prevent it from adding new children to the reaper subtree,
+        * and this should not conflict with the child stopping itself for the
+        * debugger.
+        */
+       memset(&prk, 0, sizeof(prk));
+       prk.rk_sig = SIGTERM;
+       error = procctl(P_PID, getpid(), PROC_REAP_KILL, &prk);
+       REQUIRE_EQ(error, 0);
+       REQUIRE_EQ(1, prk.rk_killed);
+       REQUIRE_EQ(-1, prk.rk_fpid);
+}
+
 ATF_TP_ADD_TCS(tp)
 {
        ATF_TP_ADD_TC(tp, ptrace__parent_wait_after_trace_me);
@@ -4434,6 +4480,7 @@ ATF_TP_ADD_TCS(tp)
        ATF_TP_ADD_TC(tp, ptrace__procdesc_wait_child);
        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__reap_kill_stopped);
 
        return (atf_no_error());
 }