diff options
Diffstat (limited to 'gdb')
| -rw-r--r-- | gdb/ChangeLog | 6 | ||||
| -rw-r--r-- | gdb/linux-nat.c | 328 |
2 files changed, 175 insertions, 159 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index fa6de88..a48c0a9 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,9 @@ +2008-03-17 Pedro Alves <pedro@codesourcery.com> + + * linux-nat.c (linux_nat_filter_event): New, refactored from + linux_nat_wait. + (linux_nat_wait): Call linux_nat_filter_event. + 2008-03-17 Ulrich Weigand <uweigand@de.ibm.com> * top.c (execute_command): Fix uninitialized variable error. diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index b021db4..9de9cf7 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -1902,6 +1902,173 @@ stop_and_resume_callback (struct lwp_info *lp, void *data) return 0; } +/* Check if we should go on and pass this event to common code. + Return the affected lpw if we are, or NULL otherwise. */ +static struct lwp_info * +linux_nat_filter_event (int lwpid, int status, int options) +{ + struct lwp_info *lp; + + lp = find_lwp_pid (pid_to_ptid (lwpid)); + + /* Check for stop events reported by a process we didn't already + know about - anything not already in our LWP list. + + If we're expecting to receive stopped processes after + fork, vfork, and clone events, then we'll just add the + new one to our list and go back to waiting for the event + to be reported - the stopped process might be returned + from waitpid before or after the event is. */ + if (WIFSTOPPED (status) && !lp) + { + linux_record_stopped_pid (lwpid, status); + return NULL; + } + + /* Make sure we don't report an event for the exit of an LWP not in + our list, i.e. not part of the current process. This can happen + if we detach from a program we original forked and then it + exits. */ + if (!WIFSTOPPED (status) && !lp) + return NULL; + + /* NOTE drow/2003-06-17: This code seems to be meant for debugging + CLONE_PTRACE processes which do not use the thread library - + otherwise we wouldn't find the new LWP this way. That doesn't + currently work, and the following code is currently unreachable + due to the two blocks above. If it's fixed some day, this code + should be broken out into a function so that we can also pick up + LWPs from the new interface. */ + if (!lp) + { + lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid))); + if (options & __WCLONE) + lp->cloned = 1; + + gdb_assert (WIFSTOPPED (status) + && WSTOPSIG (status) == SIGSTOP); + lp->signalled = 1; + + if (!in_thread_list (inferior_ptid)) + { + inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), + GET_PID (inferior_ptid)); + add_thread (inferior_ptid); + } + + add_thread (lp->ptid); + } + + /* Save the trap's siginfo in case we need it later. */ + if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP) + save_siginfo (lp); + + /* Handle GNU/Linux's extended waitstatus for trace events. */ + if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LLW: Handling extended status 0x%06x\n", + status); + if (linux_handle_extended_wait (lp, status, 0)) + return NULL; + } + + /* Check if the thread has exited. */ + if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1) + { + /* If this is the main thread, we must stop all threads and + verify if they are still alive. This is because in the nptl + thread model, there is no signal issued for exiting LWPs + other than the main thread. We only get the main thread exit + signal once all child threads have already exited. If we + stop all the threads and use the stop_wait_callback to check + if they have exited we can determine whether this signal + should be ignored or whether it means the end of the debugged + application, regardless of which threading model is being + used. */ + if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) + { + lp->stopped = 1; + iterate_over_lwps (stop_and_resume_callback, NULL); + } + + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LLW: %s exited.\n", + target_pid_to_str (lp->ptid)); + + exit_lwp (lp); + + /* If there is at least one more LWP, then the exit signal was + not the end of the debugged application and should be + ignored. */ + if (num_lwps > 0) + { + /* Make sure there is at least one thread running. */ + gdb_assert (iterate_over_lwps (running_callback, NULL)); + + /* Discard the event. */ + return NULL; + } + } + + /* Check if the current LWP has previously exited. In the nptl + thread model, LWPs other than the main thread do not issue + signals when they exit so we must check whenever the thread has + stopped. A similar check is made in stop_wait_callback(). */ + if (num_lwps > 1 && !linux_nat_thread_alive (lp->ptid)) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LLW: %s exited.\n", + target_pid_to_str (lp->ptid)); + + exit_lwp (lp); + + /* Make sure there is at least one thread running. */ + gdb_assert (iterate_over_lwps (running_callback, NULL)); + + /* Discard the event. */ + return NULL; + } + + /* Make sure we don't report a SIGSTOP that we sent ourselves in + an attempt to stop an LWP. */ + if (lp->signalled + && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) + { + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LLW: Delayed SIGSTOP caught for %s.\n", + target_pid_to_str (lp->ptid)); + + /* This is a delayed SIGSTOP. */ + lp->signalled = 0; + + registers_changed (); + + linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)), + lp->step, TARGET_SIGNAL_0); + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", + lp->step ? + "PTRACE_SINGLESTEP" : "PTRACE_CONT", + target_pid_to_str (lp->ptid)); + + lp->stopped = 0; + gdb_assert (lp->resumed); + + /* Discard the event. */ + return NULL; + } + + /* An interesting event. */ + gdb_assert (lp); + return lp; +} + static ptid_t linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus) { @@ -2034,167 +2201,10 @@ retry: (long) lwpid, status_to_str (status)); } - lp = find_lwp_pid (pid_to_ptid (lwpid)); - - /* Check for stop events reported by a process we didn't - already know about - anything not already in our LWP - list. - - If we're expecting to receive stopped processes after - fork, vfork, and clone events, then we'll just add the - new one to our list and go back to waiting for the event - to be reported - the stopped process might be returned - from waitpid before or after the event is. */ - if (WIFSTOPPED (status) && !lp) - { - linux_record_stopped_pid (lwpid, status); - status = 0; - continue; - } - - /* Make sure we don't report an event for the exit of an LWP not in - our list, i.e. not part of the current process. This can happen - if we detach from a program we original forked and then it - exits. */ - if (!WIFSTOPPED (status) && !lp) - { - status = 0; - continue; - } - - /* NOTE drow/2003-06-17: This code seems to be meant for debugging - CLONE_PTRACE processes which do not use the thread library - - otherwise we wouldn't find the new LWP this way. That doesn't - currently work, and the following code is currently unreachable - due to the two blocks above. If it's fixed some day, this code - should be broken out into a function so that we can also pick up - LWPs from the new interface. */ + lp = linux_nat_filter_event (lwpid, status, options); if (!lp) { - lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid))); - if (options & __WCLONE) - lp->cloned = 1; - - gdb_assert (WIFSTOPPED (status) - && WSTOPSIG (status) == SIGSTOP); - lp->signalled = 1; - - if (!in_thread_list (inferior_ptid)) - { - inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), - GET_PID (inferior_ptid)); - add_thread (inferior_ptid); - } - - add_thread (lp->ptid); - } - - /* Save the trap's siginfo in case we need it later. */ - if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP) - save_siginfo (lp); - - /* Handle GNU/Linux's extended waitstatus for trace events. */ - if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) - { - if (debug_linux_nat) - fprintf_unfiltered (gdb_stdlog, - "LLW: Handling extended status 0x%06x\n", - status); - if (linux_handle_extended_wait (lp, status, 0)) - { - status = 0; - continue; - } - } - - /* Check if the thread has exited. */ - if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1) - { - /* If this is the main thread, we must stop all threads and - verify if they are still alive. This is because in the nptl - thread model, there is no signal issued for exiting LWPs - other than the main thread. We only get the main thread - exit signal once all child threads have already exited. - If we stop all the threads and use the stop_wait_callback - to check if they have exited we can determine whether this - signal should be ignored or whether it means the end of the - debugged application, regardless of which threading model - is being used. */ - if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) - { - lp->stopped = 1; - iterate_over_lwps (stop_and_resume_callback, NULL); - } - - if (debug_linux_nat) - fprintf_unfiltered (gdb_stdlog, - "LLW: %s exited.\n", - target_pid_to_str (lp->ptid)); - - exit_lwp (lp); - - /* If there is at least one more LWP, then the exit signal - was not the end of the debugged application and should be - ignored. */ - if (num_lwps > 0) - { - /* Make sure there is at least one thread running. */ - gdb_assert (iterate_over_lwps (running_callback, NULL)); - - /* Discard the event. */ - status = 0; - continue; - } - } - - /* Check if the current LWP has previously exited. In the nptl - thread model, LWPs other than the main thread do not issue - signals when they exit so we must check whenever the thread - has stopped. A similar check is made in stop_wait_callback(). */ - if (num_lwps > 1 && !linux_nat_thread_alive (lp->ptid)) - { - if (debug_linux_nat) - fprintf_unfiltered (gdb_stdlog, - "LLW: %s exited.\n", - target_pid_to_str (lp->ptid)); - - exit_lwp (lp); - - /* Make sure there is at least one thread running. */ - gdb_assert (iterate_over_lwps (running_callback, NULL)); - - /* Discard the event. */ - status = 0; - continue; - } - - /* Make sure we don't report a SIGSTOP that we sent - ourselves in an attempt to stop an LWP. */ - if (lp->signalled - && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) - { - if (debug_linux_nat) - fprintf_unfiltered (gdb_stdlog, - "LLW: Delayed SIGSTOP caught for %s.\n", - target_pid_to_str (lp->ptid)); - - /* This is a delayed SIGSTOP. */ - lp->signalled = 0; - - registers_changed (); - linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)), - lp->step, TARGET_SIGNAL_0); - if (debug_linux_nat) - fprintf_unfiltered (gdb_stdlog, - "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", - lp->step ? - "PTRACE_SINGLESTEP" : "PTRACE_CONT", - target_pid_to_str (lp->ptid)); - - lp->stopped = 0; - gdb_assert (lp->resumed); - - /* Discard the event. */ + /* A discarded event. */ status = 0; continue; } |