From owner-svn-src-all@freebsd.org Wed Jan 2 19:11:51 2019 Return-Path: Delivered-To: svn-src-all@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 3B237142D592; Wed, 2 Jan 2019 19:11:51 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from mxrelay.nyi.freebsd.org (mxrelay.nyi.freebsd.org [IPv6:2610:1c1:1:606c::19:3]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "mxrelay.nyi.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id D44C66C092; Wed, 2 Jan 2019 19:11:50 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org (repo.freebsd.org [IPv6:2610:1c1:1:6068::e6a:0]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mxrelay.nyi.freebsd.org (Postfix) with ESMTPS id C6835E0DA; Wed, 2 Jan 2019 19:11:50 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from repo.freebsd.org ([127.0.1.37]) by repo.freebsd.org (8.15.2/8.15.2) with ESMTP id x02JBoLF071007; Wed, 2 Jan 2019 19:11:50 GMT (envelope-from jhb@FreeBSD.org) Received: (from jhb@localhost) by repo.freebsd.org (8.15.2/8.15.2/Submit) id x02JBolx071004; Wed, 2 Jan 2019 19:11:50 GMT (envelope-from jhb@FreeBSD.org) Message-Id: <201901021911.x02JBolx071004@repo.freebsd.org> X-Authentication-Warning: repo.freebsd.org: jhb set sender to jhb@FreeBSD.org using -f From: John Baldwin Date: Wed, 2 Jan 2019 19:11:50 +0000 (UTC) To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-stable@freebsd.org, svn-src-stable-12@freebsd.org Subject: svn commit: r342704 - in stable: 10/sys/kern 10/tests/sys/kern 11/sys/kern 11/tests/sys/kern 12/sys/kern 12/tests/sys/kern X-SVN-Group: stable-12 X-SVN-Commit-Author: jhb X-SVN-Commit-Paths: in stable: 10/sys/kern 10/tests/sys/kern 11/sys/kern 11/tests/sys/kern 12/sys/kern 12/tests/sys/kern X-SVN-Commit-Revision: 342704 X-SVN-Commit-Repository: base MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: D44C66C092 X-Spamd-Bar: -- Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-2.97 / 15.00]; local_wl_from(0.00)[FreeBSD.org]; NEURAL_HAM_MEDIUM(-1.00)[-0.999,0]; NEURAL_HAM_SHORT(-0.97)[-0.970,0]; ASN(0.00)[asn:11403, ipnet:2610:1c1:1::/48, country:US]; NEURAL_HAM_LONG(-1.00)[-0.998,0] X-BeenThere: svn-src-all@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: "SVN commit messages for the entire src tree \(except for " user" and " projects" \)" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 02 Jan 2019 19:11:51 -0000 Author: jhb Date: Wed Jan 2 19:11:49 2019 New Revision: 342704 URL: https://svnweb.freebsd.org/changeset/base/342704 Log: MFC 341800: Don't report stale signal information in ptrace_lwpinfo. Once a signal's siginfo was copied to 'td_si' as part of the signal exchange in issignal(), it was never cleared. This caused future thread events that are reported as SIGTRAP events without signal information to report the stale siginfo in 'td_si'. For example, if a debugger created a new process and used SIGSTOP to stop it after PT_ATTACH, future system call entry / exit events would set PL_FLAG_SI with the SIGSTOP siginfo in pl_siginfo. This broke 'catch syscall' in current versions of gdb as it assumed PL_FLAG_SI with SIGTRAP indicates a breakpoint or single step trap. Modified: stable/12/sys/kern/kern_sig.c stable/12/tests/sys/kern/ptrace_test.c Directory Properties: stable/12/ (props changed) Changes in other areas also in this revision: Modified: stable/10/sys/kern/kern_sig.c stable/10/tests/sys/kern/ptrace_test.c stable/11/sys/kern/kern_sig.c stable/11/tests/sys/kern/ptrace_test.c Directory Properties: stable/10/ (props changed) stable/11/ (props changed) Modified: stable/12/sys/kern/kern_sig.c ============================================================================== --- stable/12/sys/kern/kern_sig.c Wed Jan 2 18:35:40 2019 (r342703) +++ stable/12/sys/kern/kern_sig.c Wed Jan 2 19:11:49 2019 (r342704) @@ -2847,6 +2847,8 @@ issignal(struct thread *td) sig = ptracestop(td, sig, &ksi); mtx_lock(&ps->ps_mtx); + td->td_si.si_signo = 0; + /* * Keep looking if the debugger discarded or * replaced the signal. Modified: stable/12/tests/sys/kern/ptrace_test.c ============================================================================== --- stable/12/tests/sys/kern/ptrace_test.c Wed Jan 2 18:35:40 2019 (r342703) +++ stable/12/tests/sys/kern/ptrace_test.c Wed Jan 2 19:11:49 2019 (r342704) @@ -3772,6 +3772,78 @@ ATF_TC_BODY(ptrace__PT_CONTINUE_different_thread, tc) } #endif +/* + * Verify that PT_LWPINFO doesn't return stale siginfo. + */ +ATF_TC_WITHOUT_HEAD(ptrace__PT_LWPINFO_stale_siginfo); +ATF_TC_BODY(ptrace__PT_LWPINFO_stale_siginfo, tc) +{ + struct ptrace_lwpinfo pl; + pid_t fpid, wpid; + int events, status; + + ATF_REQUIRE((fpid = fork()) != -1); + if (fpid == 0) { + trace_me(); + raise(SIGABRT); + exit(1); + } + + /* The first wait() should report the stop from SIGSTOP. */ + wpid = waitpid(fpid, &status, 0); + ATF_REQUIRE(wpid == fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + ATF_REQUIRE(WSTOPSIG(status) == SIGSTOP); + + ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, 0) == 0); + + /* The next stop should report the SIGABRT in the child body. */ + wpid = waitpid(fpid, &status, 0); + ATF_REQUIRE(wpid == fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + ATF_REQUIRE(WSTOPSIG(status) == SIGABRT); + + ATF_REQUIRE(ptrace(PT_LWPINFO, wpid, (caddr_t)&pl, sizeof(pl)) != -1); + ATF_REQUIRE(pl.pl_flags & PL_FLAG_SI); + ATF_REQUIRE(pl.pl_siginfo.si_signo == SIGABRT); + + /* + * Continue the process ignoring the signal, but enabling + * syscall traps. + */ + ATF_REQUIRE(ptrace(PT_SYSCALL, fpid, (caddr_t)1, 0) == 0); + + /* + * The next stop should report a system call entry from + * exit(). PL_FLAGS_SI should not be set. + */ + wpid = waitpid(fpid, &status, 0); + ATF_REQUIRE(wpid == fpid); + ATF_REQUIRE(WIFSTOPPED(status)); + ATF_REQUIRE(WSTOPSIG(status) == SIGTRAP); + + ATF_REQUIRE(ptrace(PT_LWPINFO, wpid, (caddr_t)&pl, sizeof(pl)) != -1); + ATF_REQUIRE(pl.pl_flags & PL_FLAG_SCE); + ATF_REQUIRE((pl.pl_flags & PL_FLAG_SI) == 0); + + /* Disable syscall tracing and continue the child to let it exit. */ + ATF_REQUIRE(ptrace(PT_GET_EVENT_MASK, fpid, (caddr_t)&events, + sizeof(events)) == 0); + events &= ~PTRACE_SYSCALL; + ATF_REQUIRE(ptrace(PT_SET_EVENT_MASK, fpid, (caddr_t)&events, + sizeof(events)) == 0); + ATF_REQUIRE(ptrace(PT_CONTINUE, fpid, (caddr_t)1, 0) == 0); + + /* The last event should be for the child process's exit. */ + wpid = waitpid(fpid, &status, 0); + ATF_REQUIRE(WIFEXITED(status)); + ATF_REQUIRE(WEXITSTATUS(status) == 1); + + wpid = wait(&status); + ATF_REQUIRE(wpid == -1); + ATF_REQUIRE(errno == ECHILD); +} + ATF_TP_ADD_TCS(tp) { @@ -3831,6 +3903,7 @@ ATF_TP_ADD_TCS(tp) #if defined(HAVE_BREAKPOINT) && defined(SKIP_BREAK) ATF_TP_ADD_TC(tp, ptrace__PT_CONTINUE_different_thread); #endif + ATF_TP_ADD_TC(tp, ptrace__PT_LWPINFO_stale_siginfo); return (atf_no_error()); }