From FEDORA_PATCHES Mon Sep 17 00:00:00 2001 From: Fedora GDB patches Date: Fri, 27 Oct 2017 21:07:50 +0200 Subject: gdb-gnat-dwarf-crash-3of3.patch ;; Fix crash of -readnow /usr/lib/debug/usr/bin/gnatbind.debug (BZ 1069211). ;;=push+jan http://sourceware.org/ml/gdb-patches/2014-02/msg00731.html --6TrnltStXW4iwmi0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Hi, PR 16581: GDB crash on inherit_abstract_dies infinite recursion https://sourceware.org/bugzilla/show_bug.cgi?id=16581 fixed crash from an infinite recursion. But in rare cases the new code can now gdb_assert() due to weird DWARF file. I do not yet fully understand why the DWARF is as it is but just GDB should never crash due to invalid DWARF anyway. The "invalid" DWARF I see only in Fedora GCC build, not in FSF GCC build, more info at: https://bugzilla.redhat.com/show_bug.cgi?id=1069382 http://people.redhat.com/jkratoch/gcc-debuginfo-4.8.2-7.fc20.x86_64-gnatbind.debug Thanks, Jan --6TrnltStXW4iwmi0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline; filename="complaint.patch" gdb/ 2014-02-24 Jan Kratochvil * dwarf2read.c (process_die): Change gdb_assert to complaint. diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c --- a/gdb/dwarf2read.c +++ b/gdb/dwarf2read.c @@ -10657,6 +10657,13 @@ private: static void process_die (struct die_info *die, struct dwarf2_cu *cu) { + if (die->in_process) + { + complaint (_("DIE at 0x%s attempted to be processed twice"), + sect_offset_str (die->sect_off)); + return; + } + process_die_scope scope (die, cu); switch (die->tag) diff --git a/gdb/infrun.c b/gdb/infrun.c --- a/gdb/infrun.c +++ b/gdb/infrun.c @@ -601,6 +601,13 @@ holding the child stopped. Try \"set detach-on-fork\" or \ target_pid_to_str (process_ptid).c_str ()); } +#ifdef NEED_DETACH_SIGSTOP + /* We should check PID_WAS_STOPPED and detach it stopped accordingly. + In this point of code it cannot be 1 as we would not get FORK + executed without CONTINUE first which resets PID_WAS_STOPPED. + We would have to first TARGET_STOP and WAITPID it as with running + inferior PTRACE_DETACH, SIGSTOP will ignore the signal. */ +#endif target_detach (parent_inf, 0); } diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -189,6 +189,12 @@ struct linux_nat_target *linux_target; /* Does the current host support PTRACE_GETREGSET? */ enum tribool have_ptrace_getregset = TRIBOOL_UNKNOWN; +#ifdef NEED_DETACH_SIGSTOP +/* PID of the inferior stopped by SIGSTOP before attaching (or zero). */ +static pid_t pid_was_stopped; + +#endif + static unsigned int debug_linux_nat; static void show_debug_linux_nat (struct ui_file *file, int from_tty, @@ -1030,6 +1036,9 @@ linux_nat_post_attach_wait (ptid_t ptid, int *signalled) if (debug_linux_nat) fprintf_unfiltered (gdb_stdlog, "LNPAW: Attaching to a stopped process\n"); +#ifdef NEED_DETACH_SIGSTOP + pid_was_stopped = ptid.pid (); +#endif /* The process is definitely stopped. It is in a job control stop, unless the kernel predates the TASK_STOPPED / @@ -1361,6 +1370,25 @@ get_detach_signal (struct lwp_info *lp) return gdb_signal_to_host (signo); } +#ifdef NEED_DETACH_SIGSTOP + /* Workaround RHEL-5 kernel which has unreliable PTRACE_DETACH, SIGSTOP (that + many TIDs are left unstopped). See RH Bug 496732. */ + if (lp->ptid.pid () == pid_was_stopped) + { + int err; + + errno = 0; + err = kill_lwp (lp->ptid.lwp (), SIGSTOP); + if (debug_linux_nat) + { + fprintf_unfiltered (gdb_stdlog, + "SC: lwp kill %d %s\n", + err, + errno ? safe_strerror (errno) : "ERRNO-OK"); + } + } + +#endif return 0; } @@ -1509,6 +1537,10 @@ linux_nat_target::detach (inferior *inf, int from_tty) detach_one_lwp (main_lwp, &signo); detach_success (inf); + +#ifdef NEED_DETACH_SIGSTOP + pid_was_stopped = 0; +#endif } } @@ -1766,6 +1798,16 @@ linux_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signo) return; } +#ifdef NEED_DETACH_SIGSTOP + /* At this point, we are going to resume the inferior and if we + have attached to a stopped process, we no longer should leave + it as stopped if the user detaches. PTID variable has PID set to LWP + while we need to check the real PID here. */ + + if (!step && lp && pid_was_stopped == lp->ptid.pid ()) + pid_was_stopped = 0; + +#endif if (resume_many) iterate_over_lwps (ptid, [=] (struct lwp_info *info) { @@ -3770,6 +3812,10 @@ linux_nat_target::mourn_inferior () /* Let the arch-specific native code know this process is gone. */ linux_target->low_forget_process (pid); +#ifdef NEED_DETACH_SIGSTOP + + pid_was_stopped = 0; +#endif } /* Convert a native/host siginfo object, into/from the siginfo in the diff --git a/gdb/testsuite/gdb.threads/attach-stopped.exp b/gdb/testsuite/gdb.threads/attach-stopped.exp --- a/gdb/testsuite/gdb.threads/attach-stopped.exp +++ b/gdb/testsuite/gdb.threads/attach-stopped.exp @@ -56,7 +56,65 @@ proc corefunc { threadtype } { gdb_reinitialize_dir $srcdir/$subdir gdb_load ${binfile} - # Verify that we can attach to the stopped process. + # Verify that we can attach to the process by first giving its + # executable name via the file command, and using attach with the + # process ID. + + set test "$threadtype: set file, before attach1 to stopped process" + gdb_test_multiple "file $binfile" "$test" { + -re "Load new symbol table from.*y or n. $" { + gdb_test "y" "Reading symbols from $escapedbinfile\.\.\.*done." \ + "$test (re-read)" + } + -re "Reading symbols from $escapedbinfile\.\.\.*done.*$gdb_prompt $" { + pass "$test" + } + } + + set test "$threadtype: attach1 to stopped, after setting file" + gdb_test_multiple "attach $testpid" "$test" { + -re "Attaching to program.*`?$escapedbinfile'?, process $testpid.*$gdb_prompt $" { + pass "$test" + } + } + + # ".*sleep.*clone.*" would fail on s390x as bt stops at START_THREAD there. + if {[string equal $threadtype threaded]} { + gdb_test "thread apply all bt" ".*sleep.*start_thread.*" "$threadtype: attach1 to stopped bt" + } else { + gdb_test "bt" ".*sleep.*main.*" "$threadtype: attach1 to stopped bt" + } + + # Exit and detach the process. + + gdb_exit + + # Avoid some race: + sleep 2 + + if [catch {open /proc/${testpid}/status r} fileid] { + set line2 "NOTFOUND" + } else { + gets $fileid line1; + gets $fileid line2; + close $fileid; + } + + set test "$threadtype: attach1, exit leaves process stopped" + if {[string match "*(stopped)*" $line2]} { + pass $test + } else { + fail $test + } + + # At this point, the process should still be stopped + + gdb_start + gdb_reinitialize_dir $srcdir/$subdir + gdb_load ${binfile} + + # Verify that we can attach to the process just by giving the + # process ID. set test "$threadtype: attach2 to stopped, after setting file" gdb_test_multiple "attach $testpid" "$test" {