[rpms/gdb] gdb-17.2-rebase-f44: Fix non-stop gdb -p <container>: internal error (pedro Alves, RH BZ 1318049).

[Jan Kratochvil <jan.kratochvil@redhat.com>]

A new commit has been pushed.

Repo   : rpms/gdb
Branch : gdb-17.2-rebase-f44
Commit : 76251d61028ba2e9b8aa46c5635114d0b8bc6c32
Author : Jan Kratochvil <jan.kratochvil@redhat.com>
Date   : 2016-04-06T17:36:24+02:00
Stats  : +238/-1 in 2 file(s)
URL    : https://src.fedoraproject.org/rpms/gdb/c/76251d61028ba2e9b8aa46c5635114d0b8bc6c32?branch=gdb-17.2-rebase-f44

Log:
Fix non-stop gdb -p <container>: internal error (pedro Alves, RH BZ 1318049).

---
diff --git a/gdb-rhbz1318049-gdb-p-container-internal-error.patch b/gdb-rhbz1318049-gdb-p-container-internal-error.patch
new file mode 100644
index 0000000..8126be8
--- /dev/null
+++ b/gdb-rhbz1318049-gdb-p-container-internal-error.patch
@@ -0,0 +1,230 @@
+http://post-office.corp.redhat.com/archives/debug-list/2016-April/msg00003.html
+
+>From cb8bfeaa21a2df484d3c4c35cc6ea1c4b32cefc8 Mon Sep 17 00:00:00 2001
+From: Pedro Alves <palves@redhat.com>
+Date: Wed, 6 Apr 2016 15:07:49 +0100
+Subject: [PATCH] Fix PR gdb/19828: gdb -p <process from a container>: internal
+ error
+
+When GDB attaches to a process, it looks at the /proc/PID/task/ dir
+for all clone threads of that process, and attaches to each of them.
+
+Usually, if there is more than one clone thread, it means the program
+is multi threaded and linked with pthreads.  Thus when GDB soon after
+attaching finds and loads a libthread_db matching the process, it'll
+add a thread to the thread list for each of the initially found
+lower-level LWPs.
+
+If, however, GDB fails to find/load a matching libthread_db, nothing
+is adding the LWPs to the thread list.  And because of that, "detach"
+hits an internal error:
+
+  (gdb) PASS: gdb.threads/clone-attach-detach.exp: fg attach 1: attach
+  info threads
+    Id   Target Id         Frame
+  * 1    LWP 6891 "clone-attach-de" 0x00007f87e5fd0790 in __nanosleep_nocancel () at ../sysdeps/unix/syscall-template.S:84
+  (gdb) FAIL: gdb.threads/clone-attach-detach.exp: fg attach 1: info threads shows two LWPs
+  detach
+  .../src/gdb/thread.c:1010: internal-error: is_executing: Assertion `tp' failed.
+  A problem internal to GDB has been detected,
+  further debugging may prove unreliable.
+  Quit this debugging session? (y or n)
+  FAIL: gdb.threads/clone-attach-detach.exp: fg attach 1: detach (GDB internal error)
+
+>From here:
+
+  ...
+  #8  0x00000000007ba7cc in internal_error (file=0x98ea68 ".../src/gdb/thread.c", line=1010, fmt=0x98ea30 "%s: Assertion `%s' failed.")
+      at .../src/gdb/common/errors.c:55
+  #9  0x000000000064bb83 in is_executing (ptid=...) at .../src/gdb/thread.c:1010
+  #10 0x00000000004c23bb in get_pending_status (lp=0x12c5cc0, status=0x7fffffffdc0c) at .../src/gdb/linux-nat.c:1235
+  #11 0x00000000004c2738 in detach_callback (lp=0x12c5cc0, data=0x0) at .../src/gdb/linux-nat.c:1317
+  #12 0x00000000004c1a2a in iterate_over_lwps (filter=..., callback=0x4c2599 <detach_callback>, data=0x0) at .../src/gdb/linux-nat.c:899
+  #13 0x00000000004c295c in linux_nat_detach (ops=0xe7bd30, args=0x0, from_tty=1) at .../src/gdb/linux-nat.c:1358
+  #14 0x000000000068284d in delegate_detach (self=0xe7bd30, arg1=0x0, arg2=1) at .../src/gdb/target-delegates.c:34
+  #15 0x0000000000694141 in target_detach (args=0x0, from_tty=1) at .../src/gdb/target.c:2241
+  #16 0x0000000000630582 in detach_command (args=0x0, from_tty=1) at .../src/gdb/infcmd.c:2975
+  ...
+
+Tested on x86-64 Fedora 23.  Also confirmed the test passes against
+gdbserver with with "maint set target-non-stop".
+
+gdb/ChangeLog:
+yyyy-mm-dd  Pedro Alves  <palves@redhat.com>
+
+	* linux-nat.c (attach_proc_task_lwp_callback): Add the thread to
+	GDB's thread list.
+
+testsuite/ChangeLog:
+yyyy-mm-dd  Pedro Alves  <palves@redhat.com>
+
+	* gdb.threads/clone-attach-detach.c: New file.
+	* gdb.threads/clone-attach-detach.exp: New file.
+---
+ gdb/linux-nat.c                                   |  5 ++
+ gdb/testsuite/gdb.threads/clone-attach-detach.c   | 66 +++++++++++++++++++++++
+ gdb/testsuite/gdb.threads/clone-attach-detach.exp | 63 ++++++++++++++++++++++
+ 3 files changed, 134 insertions(+)
+ create mode 100644 gdb/testsuite/gdb.threads/clone-attach-detach.c
+ create mode 100644 gdb/testsuite/gdb.threads/clone-attach-detach.exp
+
+diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c
+index 0829bcb..2025c19 100644
+--- a/gdb/linux-nat.c
++++ b/gdb/linux-nat.c
+@@ -1088,6 +1088,11 @@ attach_proc_task_lwp_callback (ptid_t ptid)
+ 	  /* We need to wait for a stop before being able to make the
+ 	     next ptrace call on this LWP.  */
+ 	  lp->must_set_ptrace_flags = 1;
++
++	  /* Also add the LWP to gdb's thread list, in case a
++	     matching libthread_db is not found (or the process uses
++	     raw clone).  */
++	  add_thread (lp->ptid);
+ 	}
+ 
+       return 1;
+diff --git a/gdb/testsuite/gdb.threads/clone-attach-detach.c b/gdb/testsuite/gdb.threads/clone-attach-detach.c
+new file mode 100644
+index 0000000..daa8f1f
+--- /dev/null
++++ b/gdb/testsuite/gdb.threads/clone-attach-detach.c
+@@ -0,0 +1,66 @@
++/* This testcase is part of GDB, the GNU debugger.
++
++   Copyright 2016 Free Software Foundation, Inc.
++
++   This program is free software; you can redistribute it and/or modify
++   it under the terms of the GNU General Public License as published by
++   the Free Software Foundation; either version 3 of the License, or
++   (at your option) any later version.
++
++   This program is distributed in the hope that it will be useful,
++   but WITHOUT ANY WARRANTY; without even the implied warranty of
++   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++   GNU General Public License for more details.
++
++   You should have received a copy of the GNU General Public License
++   along with this program.  If not, see <http://www.gnu.org/licenses/>.
++*/
++
++#define _GNU_SOURCE
++#include <sched.h>
++#include <assert.h>
++#include <stdlib.h>
++#include <sys/types.h>
++#include <sys/wait.h>
++#include <unistd.h>
++
++#define STACK_SIZE 0x1000
++
++int clone_pid;
++
++static int
++clone_fn (void *unused)
++{
++  /* Wait for alarm.  */
++  while (1)
++    sleep (1);
++  return 0;
++}
++
++int
++main (int argc, char **argv)
++{
++  unsigned char *stack;
++  int res;
++
++  alarm (300);
++
++  stack = malloc (STACK_SIZE);
++  assert (stack != NULL);
++
++#define CLONE_FLAGS (CLONE_THREAD | CLONE_SIGHAND | CLONE_VM)
++
++#ifdef __ia64__
++  clone_pid = __clone2 (clone_fn, stack, STACK_SIZE, CLONE_FLAGS, NULL);
++#else
++  clone_pid = clone (clone_fn, stack + STACK_SIZE, CLONE_FLAGS, NULL);
++#endif
++
++  assert (clone_pid > 0);
++
++  /* Wait for alarm.  */
++  while (1)
++    sleep (1);
++
++  return 0;
++}
+diff --git a/gdb/testsuite/gdb.threads/clone-attach-detach.exp b/gdb/testsuite/gdb.threads/clone-attach-detach.exp
+new file mode 100644
+index 0000000..0652108
+--- /dev/null
++++ b/gdb/testsuite/gdb.threads/clone-attach-detach.exp
+@@ -0,0 +1,63 @@
++# This testcase is part of GDB, the GNU debugger.
++
++# Copyright 2016 Free Software Foundation, Inc.
++
++# This program is free software; you can redistribute it and/or modify
++# it under the terms of the GNU General Public License as published by
++# the Free Software Foundation; either version 3 of the License, or
++# (at your option) any later version.
++#
++# This program is distributed in the hope that it will be useful,
++# but WITHOUT ANY WARRANTY; without even the implied warranty of
++# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
++# GNU General Public License for more details.
++#
++# You should have received a copy of the GNU General Public License
++# along with this program.  If not, see <http://www.gnu.org/licenses/>.
++
++# Test attach / detach from a process that uses raw clone.  We use raw
++# clone as proxy for when libthread_db is not available.
++
++# This only works on targets with the Linux kernel.
++if ![istarget *-*-linux*] {
++    return
++}
++
++if {![can_spawn_for_attach]} {
++    return 0
++}
++
++standard_testfile
++
++if [prepare_for_testing "failed to prepare" $testfile $srcfile {debug}] {
++    return -1
++}
++
++clean_restart ${binfile}
++
++set test_spawn_id [spawn_wait_for_attach $binfile]
++set testpid [spawn_id_get_pid $test_spawn_id]
++
++# Native/gdbserver.
++set thread_re "(LWP $decimal|Thread )"
++
++# Try attach / detach a few times, in case GDB ends up with stale
++# state after detaching.
++
++set attempts 3
++for {set attempt 1} {$attempt <= $attempts} {incr attempt} {
++    with_test_prefix "fg attach $attempt" {
++
++	gdb_test "attach $testpid" \
++	    "Attaching to program.*process $testpid.*" \
++	    "attach"
++
++	gdb_test "info threads" \
++	    "1.*${thread_re}.*\r\n.*2.*${thread_re}.*" \
++	    "info threads shows two LWPs"
++
++	gdb_test "detach" "Detaching from .*, process $testpid"
++    }
++}
++
++kill_wait_spawned_process $test_spawn_id
+-- 
+2.5.5
+

diff --git a/gdb.spec b/gdb.spec
index 355539b..3c55821 100644
--- a/gdb.spec
+++ b/gdb.spec
@@ -27,7 +27,7 @@ Version: 7.11
 
 # The release always contains a leading reserved number, start it at 1.
 # `upstream' is not a part of `name' to stay fully rpm dependencies compatible for the testing.
-Release: 63%{?dist}
+Release: 64%{?dist}
 
 License: GPLv3+ and GPLv3+ with exceptions and GPLv2+ and GPLv2+ with exceptions and GPL+ and LGPLv2+ and BSD and Public Domain and GFDL
 Group: Development/Debuggers
@@ -554,6 +554,9 @@ Patch1075: gdb-testsuite-readline63-sigint.patch
 #=fedoratest
 Patch1113: gdb-rhbz1261564-aarch64-hw-watchpoint-test.patch 
 
+# Fix non-stop gdb -p <container>: internal error (pedro Alves, RH BZ 1318049).
+Patch1117: gdb-rhbz1318049-gdb-p-container-internal-error.patch
+
 %if 0%{!?rhel:1} || 0%{?rhel} > 6
 # RL_STATE_FEDORA_GDB would not be found for:
 # Patch642: gdb-readline62-ask-more-rh.patch
@@ -860,6 +863,7 @@ find -name "*.info*"|xargs rm -f
 %patch331 -p1
 %patch1075 -p1
 %patch1113 -p1
+%patch1117 -p1
 
 %if 0%{?rhel:1} && 0%{?rhel} <= 7
 %patch1044 -p1
@@ -1377,6 +1381,9 @@ then
 fi
 
 %changelog
+* Wed Apr  6 2016 Jan Kratochvil <jan.kratochvil@redhat.com> - 7.11-64.fc24
+- Fix non-stop gdb -p <container>: internal error (pedro Alves, RH BZ 1318049).
+
 * Sat Mar 19 2016 Jan Kratochvil <jan.kratochvil@redhat.com> - 7.11-63.fc24
 - .spec cleanup: Drop strict-aliasing GCC bug workaround (from RH BZ 1315191).