Wed Jun 24 04:47:10 2020 UTC ()

Fix core_dump_procinfo tests for powerpc, for which child process was
stalled indefinitely in trap instruction even after PT_CONTINUE.

For powerpc, program counter is not automatically incremented by trap
instruction. We cannot increment PC in the trap handler, which breaks
applications depending on this behavior, e.g., GDB.

Therefore, we need to pass (PC + 4) instead of (void *)1 (== PC) to
PT_CONTINUE when child process traps itself.


(rin)

diff -r1.1 -r1.2 src/tests/lib/libc/sys/t_ptrace_core_wait.h

--- src/tests/lib/libc/sys/t_ptrace_core_wait.h 2020/05/05 01:24:29	1.1
+++ src/tests/lib/libc/sys/t_ptrace_core_wait.h 2020/06/24 04:47:10	1.2

 @@ -1,14 +1,14 @@
-/*	$NetBSD: t_ptrace_core_wait.h,v 1.1 2020/05/05 01:24:29 kamil Exp $	*/
+/*	$NetBSD: t_ptrace_core_wait.h,v 1.2 2020/06/24 04:47:10 rin Exp $	*/
 /*-
  * Copyright (c) 2016, 2017, 2018, 2019, 2020 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
 @@ -197,26 +197,41 @@ ATF_TC_BODY(core_dump_procinfo, tc)
 	ATF_CHECK_EQ(procinfo.cpi_pgrp, getpgid(child));
 	ATF_CHECK_EQ(procinfo.cpi_sid, getsid(child));
 	ATF_CHECK_EQ(procinfo.cpi_ruid, getuid());
 	ATF_CHECK_EQ(procinfo.cpi_euid, geteuid());
 	ATF_CHECK_EQ(procinfo.cpi_rgid, getgid());
 	ATF_CHECK_EQ(procinfo.cpi_egid, getegid());
 	ATF_CHECK_EQ(procinfo.cpi_nlwps, 1);
 	ATF_CHECK(procinfo.cpi_siglwp > 0);
 	unlink(core_path);
 	DPRINTF("Before resuming the child process where it left off and "
 	    "without signal to be sent\n");
 #ifndef __powerpc__
 	SYSCALL_REQUIRE(ptrace(PT_CONTINUE, child, (void *)1, 0) != -1);
 #else
 	/*
 	 * For powerpc, program counter is not automatically incremented by
 	 * a trap instruction. We cannot increment PC in the trap handler,
 	 * which breaks applications depending on this behavior, e.g., GDB.
 	 * Therefore, we need to pass (PC + 4) instead of (void *)1 (== PC)
 	 * to PT_CONTINUE here.
 	 */
 	struct reg r;
 	SYSCALL_REQUIRE(ptrace(PT_GETREGS, child, &r, 0) != -1);
 	SYSCALL_REQUIRE(
 	    ptrace(PT_CONTINUE, child, (void *)(r.pc + 4), 0) != -1);
 #endif
 	DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
 	TWAIT_REQUIRE_SUCCESS(wpid = TWAIT_GENERIC(child, &status, 0), child);
 	validate_status_exited(status, exitval);
 	DPRINTF("Before calling %s() for the child\n", TWAIT_FNAME);
 	TWAIT_REQUIRE_FAILURE(ECHILD, wpid = TWAIT_GENERIC(child, &status, 0));
+}
 #define ATF_TP_ADD_TCS_PTRACE_WAIT_CORE() \
 	ATF_TP_ADD_TC(tp, core_dump_procinfo);