diff options
| -rw-r--r-- | gdb/ChangeLog | 11 | ||||
| -rw-r--r-- | gdb/linux-nat.c | 97 | ||||
| -rw-r--r-- | gdb/testsuite/ChangeLog | 7 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/fork-plus-threads.c | 115 | ||||
| -rw-r--r-- | gdb/testsuite/gdb.threads/fork-plus-threads.exp | 69 |
5 files changed, 243 insertions, 56 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 4d604de..40403f9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,14 @@ +2015-07-30 Pedro Alves <palves@redhat.com> + Simon Marchi <simon.marchi@ericsson.com> + + PR threads/18600 + * linux-nat.c (linux_handle_extended_wait): On CLONE event, always + mark the new thread as resumed. Remove STOPPING parameter. + (wait_lwp): Adjust call to linux_handle_extended_wait. + (linux_nat_filter_event): Adjust call to + linux_handle_extended_wait. + (resume_stopped_resumed_lwps): Add debug output. + 2015-07-30 Pierre Langlois <pierre.langlois@arm.com> * arch-utils.c (default_fast_tracepoint_valid_at): Remove unused diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index b33abb0..966c6a8 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -2000,8 +2000,7 @@ linux_handle_syscall_trap (struct lwp_info *lp, int stopping) true, the new LWP remains stopped, otherwise it is continued. */ static int -linux_handle_extended_wait (struct lwp_info *lp, int status, - int stopping) +linux_handle_extended_wait (struct lwp_info *lp, int status) { int pid = ptid_get_lwp (lp->ptid); struct target_waitstatus *ourstatus = &lp->waitstatus; @@ -2071,7 +2070,7 @@ linux_handle_extended_wait (struct lwp_info *lp, int status, ourstatus->kind = TARGET_WAITKIND_FORKED; else if (event == PTRACE_EVENT_VFORK) ourstatus->kind = TARGET_WAITKIND_VFORKED; - else + else if (event == PTRACE_EVENT_CLONE) { struct lwp_info *new_lp; @@ -2086,43 +2085,7 @@ linux_handle_extended_wait (struct lwp_info *lp, int status, new_lp = add_lwp (ptid_build (ptid_get_pid (lp->ptid), new_pid, 0)); new_lp->cloned = 1; new_lp->stopped = 1; - - if (WSTOPSIG (status) != SIGSTOP) - { - /* This can happen if someone starts sending signals to - the new thread before it gets a chance to run, which - have a lower number than SIGSTOP (e.g. SIGUSR1). - This is an unlikely case, and harder to handle for - fork / vfork than for clone, so we do not try - but - we handle it for clone events here. We'll send - the other signal on to the thread below. */ - - new_lp->signalled = 1; - } - else - { - struct thread_info *tp; - - /* When we stop for an event in some other thread, and - pull the thread list just as this thread has cloned, - we'll have seen the new thread in the thread_db list - before handling the CLONE event (glibc's - pthread_create adds the new thread to the thread list - before clone'ing, and has the kernel fill in the - thread's tid on the clone call with - CLONE_PARENT_SETTID). If that happened, and the core - had requested the new thread to stop, we'll have - killed it with SIGSTOP. But since SIGSTOP is not an - RT signal, it can only be queued once. We need to be - careful to not resume the LWP if we wanted it to - stop. In that case, we'll leave the SIGSTOP pending. - It will later be reported as GDB_SIGNAL_0. */ - tp = find_thread_ptid (new_lp->ptid); - if (tp != NULL && tp->stop_requested) - new_lp->last_resume_kind = resume_stop; - else - status = 0; - } + new_lp->resumed = 1; /* If the thread_db layer is active, let it record the user level thread id and status, and add the thread to GDB's @@ -2136,19 +2099,23 @@ linux_handle_extended_wait (struct lwp_info *lp, int status, } /* Even if we're stopping the thread for some reason - internal to this module, from the user/frontend's - perspective, this new thread is running. */ + internal to this module, from the perspective of infrun + and the user/frontend, this new thread is running until + it next reports a stop. */ set_running (new_lp->ptid, 1); - if (!stopping) - { - set_executing (new_lp->ptid, 1); - /* thread_db_attach_lwp -> lin_lwp_attach_lwp forced - resume_stop. */ - new_lp->last_resume_kind = resume_continue; - } + set_executing (new_lp->ptid, 1); - if (status != 0) + if (WSTOPSIG (status) != SIGSTOP) { + /* This can happen if someone starts sending signals to + the new thread before it gets a chance to run, which + have a lower number than SIGSTOP (e.g. SIGUSR1). + This is an unlikely case, and harder to handle for + fork / vfork than for clone, so we do not try - but + we handle it for clone events here. */ + + new_lp->signalled = 1; + /* We created NEW_LP so it cannot yet contain STATUS. */ gdb_assert (new_lp->status == 0); @@ -2162,7 +2129,6 @@ linux_handle_extended_wait (struct lwp_info *lp, int status, new_lp->status = status; } - new_lp->resumed = !stopping; return 1; } @@ -2353,7 +2319,7 @@ wait_lwp (struct lwp_info *lp) fprintf_unfiltered (gdb_stdlog, "WL: Handling extended status 0x%06x\n", status); - linux_handle_extended_wait (lp, status, 1); + linux_handle_extended_wait (lp, status); return 0; } @@ -3155,7 +3121,7 @@ linux_nat_filter_event (int lwpid, int status) fprintf_unfiltered (gdb_stdlog, "LLW: Handling extended status 0x%06x\n", status); - if (linux_handle_extended_wait (lp, status, 0)) + if (linux_handle_extended_wait (lp, status)) return NULL; } @@ -3675,9 +3641,28 @@ resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) { ptid_t *wait_ptid_p = data; - if (lp->stopped - && lp->resumed - && !lwp_status_pending_p (lp)) + if (!lp->stopped) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "RSRL: NOT resuming LWP %s, not stopped\n", + target_pid_to_str (lp->ptid)); + } + else if (!lp->resumed) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "RSRL: NOT resuming LWP %s, not resumed\n", + target_pid_to_str (lp->ptid)); + } + else if (lwp_status_pending_p (lp)) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "RSRL: NOT resuming LWP %s, has pending status\n", + target_pid_to_str (lp->ptid)); + } + else { struct regcache *regcache = get_thread_regcache (lp->ptid); struct gdbarch *gdbarch = get_regcache_arch (regcache); diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog index 171784e..06ca987 100644 --- a/gdb/testsuite/ChangeLog +++ b/gdb/testsuite/ChangeLog @@ -1,3 +1,10 @@ +2015-07-30 Simon Marchi <simon.marchi@ericsson.com> + Pedro Alves <palves@redhat.com> + + PR threads/18600 + * gdb.threads/fork-plus-threads.c: New file. + * gdb.threads/fork-plus-threads.exp: New file. + 2015-07-29 Patrick Palka <patrick@parcs.ath.cx> * gdb.base/batch-preserve-term-settings.exp diff --git a/gdb/testsuite/gdb.threads/fork-plus-threads.c b/gdb/testsuite/gdb.threads/fork-plus-threads.c new file mode 100644 index 0000000..780a4b8 --- /dev/null +++ b/gdb/testsuite/gdb.threads/fork-plus-threads.c @@ -0,0 +1,115 @@ +/* This testcase is part of GDB, the GNU debugger. + + Copyright 2015 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/>. */ + +#include <assert.h> +#include <pthread.h> +#include <unistd.h> +#include <stdio.h> +#include <sys/types.h> +#include <sys/wait.h> + + +/* Number of times the main process forks. */ +#define NFORKS 10 + +/* Number of threads by each fork child. */ +#define NTHREADS 10 + +static void * +thread_func (void *arg) +{ + /* Empty. */ +} + +static void +fork_child (void) +{ + pthread_t threads[NTHREADS]; + int i; + int ret; + + for (i = 0; i < NTHREADS; i++) + { + ret = pthread_create (&threads[i], NULL, thread_func, NULL); + assert (ret == 0); + } + + for (i = 0; i < NTHREADS; i++) + { + ret = pthread_join (threads[i], NULL); + assert (ret == 0); + } +} + +int +main (void) +{ + pid_t childs[NFORKS]; + int i; + int status; + int num_exited = 0; + + /* Don't run forever if the wait loop below gets stuck. */ + alarm (180); + + for (i = 0; i < NFORKS; i++) + { + pid_t pid; + + pid = fork (); + + if (pid > 0) + { + /* Parent. */ + childs[i] = pid; + } + else if (pid == 0) + { + /* Child. */ + fork_child (); + return 0; + } + else + { + perror ("fork"); + return 1; + } + } + + while (num_exited != NFORKS) + { + pid_t pid = wait (&status); + + if (pid == -1) + { + perror ("wait"); + return 1; + } + + if (WIFEXITED (status)) + { + num_exited++; + } + else + { + printf ("Hmm, unexpected wait status 0x%x from child %d\n", status, + pid); + } + } + + return 0; +} diff --git a/gdb/testsuite/gdb.threads/fork-plus-threads.exp b/gdb/testsuite/gdb.threads/fork-plus-threads.exp new file mode 100644 index 0000000..53d1102 --- /dev/null +++ b/gdb/testsuite/gdb.threads/fork-plus-threads.exp @@ -0,0 +1,69 @@ +# Copyright (C) 2015 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/>. + +# This test verifies that threads created by the child fork are +# properly handled. Specifically, GDB used to have a bug where it +# would leave child fork threads stuck stopped, even though "info +# threads" would show them running. +# +# See https://sourceware.org/bugzilla/show_bug.cgi?id=18600 + +standard_testfile + +proc do_test { detach_on_fork } { + global GDBFLAGS + global srcfile testfile + global gdb_prompt + + set saved_gdbflags $GDBFLAGS + set GDBFLAGS [concat $GDBFLAGS " -ex \"set non-stop on\""] + + if {[prepare_for_testing "failed to prepare" \ + $testfile $srcfile {debug pthreads}] == -1} { + set GDBFLAGS $saved_gdbflags + return -1 + } + + set GDBFLAGS $saved_gdbflags + + if ![runto_main] then { + fail "Can't run to main" + return 0 + } + + gdb_test_no_output "set detach-on-fork $detach_on_fork" + set test "continue &" + gdb_test_multiple $test $test { + -re "$gdb_prompt " { + pass $test + } + } + + set test "inferior 1 exited" + gdb_test_multiple "" $test { + -re "Inferior 1 \(\[^\r\n\]+\) exited normally" { + pass $test + } + } + + gdb_test "info threads" "No threads\." \ + "no threads left" +} + +foreach detach_on_fork {"on" "off"} { + with_test_prefix "detach-on-fork=$detach_on_fork" { + do_test $detach_on_fork + } +} |