| /* Low level interface to ptrace, for the remote server for GDB. |
| Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002 |
| Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| 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 2 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, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "server.h" |
| #include "linux-low.h" |
| |
| #include <sys/wait.h> |
| #include <stdio.h> |
| #include <sys/param.h> |
| #include <sys/dir.h> |
| #include <sys/ptrace.h> |
| #include <sys/user.h> |
| #include <signal.h> |
| #include <sys/ioctl.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| |
| /* ``all_threads'' is keyed by the LWP ID - it should be the thread ID instead, |
| however. This requires changing the ID in place when we go from !using_threads |
| to using_threads, immediately. |
| |
| ``all_processes'' is keyed by the process ID - which on Linux is (presently) |
| the same as the LWP ID. */ |
| |
| struct inferior_list all_processes; |
| |
| /* FIXME this is a bit of a hack, and could be removed. */ |
| int stopping_threads; |
| |
| /* FIXME make into a target method? */ |
| int using_threads; |
| |
| static void linux_resume_one_process (struct inferior_list_entry *entry, |
| int step, int signal); |
| static void linux_resume (int step, int signal); |
| static void stop_all_processes (void); |
| static int linux_wait_for_event (struct thread_info *child); |
| |
| struct pending_signals |
| { |
| int signal; |
| struct pending_signals *prev; |
| }; |
| |
| #define PTRACE_ARG3_TYPE long |
| #define PTRACE_XFER_TYPE long |
| |
| #ifdef HAVE_LINUX_REGSETS |
| static int use_regsets_p = 1; |
| #endif |
| |
| extern int errno; |
| |
| int debug_threads = 0; |
| |
| #define pid_of(proc) ((proc)->head.id) |
| |
| /* FIXME: Delete eventually. */ |
| #define inferior_pid (pid_of (get_thread_process (current_inferior))) |
| |
| /* This function should only be called if the process got a SIGTRAP. |
| The SIGTRAP could mean several things. |
| |
| On i386, where decr_pc_after_break is non-zero: |
| If we were single-stepping this process using PTRACE_SINGLESTEP, |
| we will get only the one SIGTRAP (even if the instruction we |
| stepped over was a breakpoint). The value of $eip will be the |
| next instruction. |
| If we continue the process using PTRACE_CONT, we will get a |
| SIGTRAP when we hit a breakpoint. The value of $eip will be |
| the instruction after the breakpoint (i.e. needs to be |
| decremented). If we report the SIGTRAP to GDB, we must also |
| report the undecremented PC. If we cancel the SIGTRAP, we |
| must resume at the decremented PC. |
| |
| (Presumably, not yet tested) On a non-decr_pc_after_break machine |
| with hardware or kernel single-step: |
| If we single-step over a breakpoint instruction, our PC will |
| point at the following instruction. If we continue and hit a |
| breakpoint instruction, our PC will point at the breakpoint |
| instruction. */ |
| |
| static CORE_ADDR |
| get_stop_pc (void) |
| { |
| CORE_ADDR stop_pc = (*the_low_target.get_pc) (); |
| |
| if (get_thread_process (current_inferior)->stepping) |
| return stop_pc; |
| else |
| return stop_pc - the_low_target.decr_pc_after_break; |
| } |
| |
| static void * |
| add_process (int pid) |
| { |
| struct process_info *process; |
| |
| process = (struct process_info *) malloc (sizeof (*process)); |
| memset (process, 0, sizeof (*process)); |
| |
| process->head.id = pid; |
| |
| /* Default to tid == lwpid == pid. */ |
| process->tid = pid; |
| process->lwpid = pid; |
| |
| add_inferior_to_list (&all_processes, &process->head); |
| |
| return process; |
| } |
| |
| /* Start an inferior process and returns its pid. |
| ALLARGS is a vector of program-name and args. */ |
| |
| static int |
| linux_create_inferior (char *program, char **allargs) |
| { |
| void *new_process; |
| int pid; |
| |
| pid = fork (); |
| if (pid < 0) |
| perror_with_name ("fork"); |
| |
| if (pid == 0) |
| { |
| ptrace (PTRACE_TRACEME, 0, 0, 0); |
| |
| signal (__SIGRTMIN + 1, SIG_DFL); |
| |
| setpgid (0, 0); |
| |
| execv (program, allargs); |
| |
| fprintf (stderr, "Cannot exec %s: %s.\n", program, |
| strerror (errno)); |
| fflush (stderr); |
| _exit (0177); |
| } |
| |
| new_process = add_process (pid); |
| add_thread (pid, new_process); |
| |
| return pid; |
| } |
| |
| /* Attach to an inferior process. */ |
| |
| void |
| linux_attach_lwp (int pid, int tid) |
| { |
| struct process_info *new_process; |
| |
| if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) |
| { |
| fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid, |
| strerror (errno), errno); |
| fflush (stderr); |
| |
| /* If we fail to attach to an LWP, just return. */ |
| if (!using_threads) |
| _exit (0177); |
| return; |
| } |
| |
| new_process = (struct process_info *) add_process (pid); |
| add_thread (tid, new_process); |
| |
| /* The next time we wait for this LWP we'll see a SIGSTOP as PTRACE_ATTACH |
| brings it to a halt. We should ignore that SIGSTOP and resume the process |
| (unless this is the first process, in which case the flag will be cleared |
| in linux_attach). |
| |
| On the other hand, if we are currently trying to stop all threads, we |
| should treat the new thread as if we had sent it a SIGSTOP. This works |
| because we are guaranteed that add_process added us to the end of the |
| list, and so the new thread has not yet reached wait_for_sigstop (but |
| will). */ |
| if (! stopping_threads) |
| new_process->stop_expected = 1; |
| } |
| |
| int |
| linux_attach (int pid) |
| { |
| struct process_info *process; |
| |
| linux_attach_lwp (pid, pid); |
| |
| /* Don't ignore the initial SIGSTOP if we just attached to this process. */ |
| process = (struct process_info *) find_inferior_id (&all_processes, pid); |
| process->stop_expected = 0; |
| |
| return 0; |
| } |
| |
| /* Kill the inferior process. Make us have no inferior. */ |
| |
| static void |
| linux_kill_one_process (struct inferior_list_entry *entry) |
| { |
| struct thread_info *thread = (struct thread_info *) entry; |
| struct process_info *process = get_thread_process (thread); |
| int wstat; |
| |
| do |
| { |
| ptrace (PTRACE_KILL, pid_of (process), 0, 0); |
| |
| /* Make sure it died. The loop is most likely unnecessary. */ |
| wstat = linux_wait_for_event (thread); |
| } while (WIFSTOPPED (wstat)); |
| } |
| |
| static void |
| linux_kill (void) |
| { |
| for_each_inferior (&all_threads, linux_kill_one_process); |
| } |
| |
| static void |
| linux_detach_one_process (struct inferior_list_entry *entry) |
| { |
| struct thread_info *thread = (struct thread_info *) entry; |
| struct process_info *process = get_thread_process (thread); |
| |
| ptrace (PTRACE_DETACH, pid_of (process), 0, 0); |
| } |
| |
| static void |
| linux_detach (void) |
| { |
| for_each_inferior (&all_threads, linux_detach_one_process); |
| } |
| |
| /* Return nonzero if the given thread is still alive. */ |
| static int |
| linux_thread_alive (int tid) |
| { |
| if (find_inferior_id (&all_threads, tid) != NULL) |
| return 1; |
| else |
| return 0; |
| } |
| |
| /* Return nonzero if this process stopped at a breakpoint which |
| no longer appears to be inserted. Also adjust the PC |
| appropriately to resume where the breakpoint used to be. */ |
| static int |
| check_removed_breakpoint (struct process_info *event_child) |
| { |
| CORE_ADDR stop_pc; |
| struct thread_info *saved_inferior; |
| |
| if (event_child->pending_is_breakpoint == 0) |
| return 0; |
| |
| if (debug_threads) |
| fprintf (stderr, "Checking for breakpoint.\n"); |
| |
| saved_inferior = current_inferior; |
| current_inferior = get_process_thread (event_child); |
| |
| stop_pc = get_stop_pc (); |
| |
| /* If the PC has changed since we stopped, then we shouldn't do |
| anything. This happens if, for instance, GDB handled the |
| decr_pc_after_break subtraction itself. */ |
| if (stop_pc != event_child->pending_stop_pc) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Ignoring, PC was changed.\n"); |
| |
| event_child->pending_is_breakpoint = 0; |
| current_inferior = saved_inferior; |
| return 0; |
| } |
| |
| /* If the breakpoint is still there, we will report hitting it. */ |
| if ((*the_low_target.breakpoint_at) (stop_pc)) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Ignoring, breakpoint is still present.\n"); |
| current_inferior = saved_inferior; |
| return 0; |
| } |
| |
| if (debug_threads) |
| fprintf (stderr, "Removed breakpoint.\n"); |
| |
| /* For decr_pc_after_break targets, here is where we perform the |
| decrement. We go immediately from this function to resuming, |
| and can not safely call get_stop_pc () again. */ |
| if (the_low_target.set_pc != NULL) |
| (*the_low_target.set_pc) (stop_pc); |
| |
| /* We consumed the pending SIGTRAP. */ |
| event_child->status_pending_p = 0; |
| event_child->status_pending = 0; |
| |
| current_inferior = saved_inferior; |
| return 1; |
| } |
| |
| /* Return 1 if this process has an interesting status pending. This function |
| may silently resume an inferior process. */ |
| static int |
| status_pending_p (struct inferior_list_entry *entry, void *dummy) |
| { |
| struct process_info *process = (struct process_info *) entry; |
| |
| if (process->status_pending_p) |
| if (check_removed_breakpoint (process)) |
| { |
| /* This thread was stopped at a breakpoint, and the breakpoint |
| is now gone. We were told to continue (or step...) all threads, |
| so GDB isn't trying to single-step past this breakpoint. |
| So instead of reporting the old SIGTRAP, pretend we got to |
| the breakpoint just after it was removed instead of just |
| before; resume the process. */ |
| linux_resume_one_process (&process->head, 0, 0); |
| return 0; |
| } |
| |
| return process->status_pending_p; |
| } |
| |
| static void |
| linux_wait_for_process (struct process_info **childp, int *wstatp) |
| { |
| int ret; |
| int to_wait_for = -1; |
| |
| if (*childp != NULL) |
| to_wait_for = (*childp)->lwpid; |
| |
| while (1) |
| { |
| ret = waitpid (to_wait_for, wstatp, WNOHANG); |
| |
| if (ret == -1) |
| { |
| if (errno != ECHILD) |
| perror_with_name ("waitpid"); |
| } |
| else if (ret > 0) |
| break; |
| |
| ret = waitpid (to_wait_for, wstatp, WNOHANG | __WCLONE); |
| |
| if (ret == -1) |
| { |
| if (errno != ECHILD) |
| perror_with_name ("waitpid (WCLONE)"); |
| } |
| else if (ret > 0) |
| break; |
| |
| usleep (1000); |
| } |
| |
| if (debug_threads |
| && (!WIFSTOPPED (*wstatp) |
| || (WSTOPSIG (*wstatp) != 32 |
| && WSTOPSIG (*wstatp) != 33))) |
| fprintf (stderr, "Got an event from %d (%x)\n", ret, *wstatp); |
| |
| if (to_wait_for == -1) |
| *childp = (struct process_info *) find_inferior_id (&all_processes, ret); |
| |
| (*childp)->stopped = 1; |
| (*childp)->pending_is_breakpoint = 0; |
| |
| if (debug_threads |
| && WIFSTOPPED (*wstatp)) |
| { |
| current_inferior = (struct thread_info *) |
| find_inferior_id (&all_threads, (*childp)->tid); |
| /* For testing only; i386_stop_pc prints out a diagnostic. */ |
| if (the_low_target.get_pc != NULL) |
| get_stop_pc (); |
| } |
| } |
| |
| static int |
| linux_wait_for_event (struct thread_info *child) |
| { |
| CORE_ADDR stop_pc; |
| struct process_info *event_child; |
| int wstat; |
| |
| /* Check for a process with a pending status. */ |
| /* It is possible that the user changed the pending task's registers since |
| it stopped. We correctly handle the change of PC if we hit a breakpoint |
| (in check_removed_breakpoint); signals should be reported anyway. */ |
| if (child == NULL) |
| { |
| event_child = (struct process_info *) |
| find_inferior (&all_processes, status_pending_p, NULL); |
| if (debug_threads && event_child) |
| fprintf (stderr, "Got a pending child %d\n", event_child->lwpid); |
| } |
| else |
| { |
| event_child = get_thread_process (child); |
| if (event_child->status_pending_p |
| && check_removed_breakpoint (event_child)) |
| event_child = NULL; |
| } |
| |
| if (event_child != NULL) |
| { |
| if (event_child->status_pending_p) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Got an event from pending child %d (%04x)\n", |
| event_child->lwpid, event_child->status_pending); |
| wstat = event_child->status_pending; |
| event_child->status_pending_p = 0; |
| event_child->status_pending = 0; |
| current_inferior = get_process_thread (event_child); |
| return wstat; |
| } |
| } |
| |
| /* We only enter this loop if no process has a pending wait status. Thus |
| any action taken in response to a wait status inside this loop is |
| responding as soon as we detect the status, not after any pending |
| events. */ |
| while (1) |
| { |
| if (child == NULL) |
| event_child = NULL; |
| else |
| event_child = get_thread_process (child); |
| |
| linux_wait_for_process (&event_child, &wstat); |
| |
| if (event_child == NULL) |
| error ("event from unknown child"); |
| |
| current_inferior = (struct thread_info *) |
| find_inferior_id (&all_threads, event_child->tid); |
| |
| if (using_threads) |
| { |
| /* Check for thread exit. */ |
| if (! WIFSTOPPED (wstat)) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Thread %d (LWP %d) exiting\n", |
| event_child->tid, event_child->head.id); |
| |
| /* If the last thread is exiting, just return. */ |
| if (all_threads.head == all_threads.tail) |
| return wstat; |
| |
| dead_thread_notify (event_child->tid); |
| |
| remove_inferior (&all_processes, &event_child->head); |
| free (event_child); |
| remove_thread (current_inferior); |
| current_inferior = (struct thread_info *) all_threads.head; |
| |
| /* If we were waiting for this particular child to do something... |
| well, it did something. */ |
| if (child != NULL) |
| return wstat; |
| |
| /* Wait for a more interesting event. */ |
| continue; |
| } |
| |
| if (WIFSTOPPED (wstat) |
| && WSTOPSIG (wstat) == SIGSTOP |
| && event_child->stop_expected) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Expected stop.\n"); |
| event_child->stop_expected = 0; |
| linux_resume_one_process (&event_child->head, |
| event_child->stepping, 0); |
| continue; |
| } |
| |
| /* FIXME drow/2002-06-09: Get signal numbers from the inferior's |
| thread library? */ |
| if (WIFSTOPPED (wstat) |
| && (WSTOPSIG (wstat) == __SIGRTMIN |
| || WSTOPSIG (wstat) == __SIGRTMIN + 1)) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Ignored signal %d for %d (LWP %d).\n", |
| WSTOPSIG (wstat), event_child->tid, |
| event_child->head.id); |
| linux_resume_one_process (&event_child->head, |
| event_child->stepping, |
| WSTOPSIG (wstat)); |
| continue; |
| } |
| } |
| |
| /* If this event was not handled above, and is not a SIGTRAP, report |
| it. */ |
| if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP) |
| return wstat; |
| |
| /* If this target does not support breakpoints, we simply report the |
| SIGTRAP; it's of no concern to us. */ |
| if (the_low_target.get_pc == NULL) |
| return wstat; |
| |
| stop_pc = get_stop_pc (); |
| |
| /* bp_reinsert will only be set if we were single-stepping. |
| Notice that we will resume the process after hitting |
| a gdbserver breakpoint; single-stepping to/over one |
| is not supported (yet). */ |
| if (event_child->bp_reinsert != 0) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Reinserted breakpoint.\n"); |
| reinsert_breakpoint (event_child->bp_reinsert); |
| event_child->bp_reinsert = 0; |
| |
| /* Clear the single-stepping flag and SIGTRAP as we resume. */ |
| linux_resume_one_process (&event_child->head, 0, 0); |
| continue; |
| } |
| |
| if (debug_threads) |
| fprintf (stderr, "Hit a (non-reinsert) breakpoint.\n"); |
| |
| if (check_breakpoints (stop_pc) != 0) |
| { |
| /* We hit one of our own breakpoints. We mark it as a pending |
| breakpoint, so that check_removed_breakpoint () will do the PC |
| adjustment for us at the appropriate time. */ |
| event_child->pending_is_breakpoint = 1; |
| event_child->pending_stop_pc = stop_pc; |
| |
| /* Now we need to put the breakpoint back. We continue in the event |
| loop instead of simply replacing the breakpoint right away, |
| in order to not lose signals sent to the thread that hit the |
| breakpoint. Unfortunately this increases the window where another |
| thread could sneak past the removed breakpoint. For the current |
| use of server-side breakpoints (thread creation) this is |
| acceptable; but it needs to be considered before this breakpoint |
| mechanism can be used in more general ways. For some breakpoints |
| it may be necessary to stop all other threads, but that should |
| be avoided where possible. |
| |
| If breakpoint_reinsert_addr is NULL, that means that we can |
| use PTRACE_SINGLESTEP on this platform. Uninsert the breakpoint, |
| mark it for reinsertion, and single-step. |
| |
| Otherwise, call the target function to figure out where we need |
| our temporary breakpoint, create it, and continue executing this |
| process. */ |
| if (the_low_target.breakpoint_reinsert_addr == NULL) |
| { |
| event_child->bp_reinsert = stop_pc; |
| uninsert_breakpoint (stop_pc); |
| linux_resume_one_process (&event_child->head, 1, 0); |
| } |
| else |
| { |
| reinsert_breakpoint_by_bp |
| (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ()); |
| linux_resume_one_process (&event_child->head, 0, 0); |
| } |
| |
| continue; |
| } |
| |
| /* If we were single-stepping, we definitely want to report the |
| SIGTRAP. The single-step operation has completed, so also |
| clear the stepping flag; in general this does not matter, |
| because the SIGTRAP will be reported to the client, which |
| will give us a new action for this thread, but clear it for |
| consistency anyway. It's safe to clear the stepping flag |
| because the only consumer of get_stop_pc () after this point |
| is check_removed_breakpoint, and pending_is_breakpoint is not |
| set. It might be wiser to use a step_completed flag instead. */ |
| if (event_child->stepping) |
| { |
| event_child->stepping = 0; |
| return wstat; |
| } |
| |
| /* A SIGTRAP that we can't explain. It may have been a breakpoint. |
| Check if it is a breakpoint, and if so mark the process information |
| accordingly. This will handle both the necessary fiddling with the |
| PC on decr_pc_after_break targets and suppressing extra threads |
| hitting a breakpoint if two hit it at once and then GDB removes it |
| after the first is reported. Arguably it would be better to report |
| multiple threads hitting breakpoints simultaneously, but the current |
| remote protocol does not allow this. */ |
| if ((*the_low_target.breakpoint_at) (stop_pc)) |
| { |
| event_child->pending_is_breakpoint = 1; |
| event_child->pending_stop_pc = stop_pc; |
| } |
| |
| return wstat; |
| } |
| |
| /* NOTREACHED */ |
| return 0; |
| } |
| |
| /* Wait for process, returns status. */ |
| |
| static unsigned char |
| linux_wait (char *status) |
| { |
| int w; |
| struct thread_info *child = NULL; |
| |
| retry: |
| /* If we were only supposed to resume one thread, only wait for |
| that thread - if it's still alive. If it died, however - which |
| can happen if we're coming from the thread death case below - |
| then we need to make sure we restart the other threads. We could |
| pick a thread at random or restart all; restarting all is less |
| arbitrary. */ |
| if (cont_thread > 0) |
| { |
| child = (struct thread_info *) find_inferior_id (&all_threads, |
| cont_thread); |
| |
| /* No stepping, no signal - unless one is pending already, of course. */ |
| if (child == NULL) |
| linux_resume (0, 0); |
| } |
| |
| enable_async_io (); |
| w = linux_wait_for_event (child); |
| stop_all_processes (); |
| disable_async_io (); |
| |
| /* If we are waiting for a particular child, and it exited, |
| linux_wait_for_event will return its exit status. Similarly if |
| the last child exited. If this is not the last child, however, |
| do not report it as exited until there is a 'thread exited' response |
| available in the remote protocol. Instead, just wait for another event. |
| This should be safe, because if the thread crashed we will already |
| have reported the termination signal to GDB; that should stop any |
| in-progress stepping operations, etc. |
| |
| Report the exit status of the last thread to exit. This matches |
| LinuxThreads' behavior. */ |
| |
| if (all_threads.head == all_threads.tail) |
| { |
| if (WIFEXITED (w)) |
| { |
| fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); |
| *status = 'W'; |
| clear_inferiors (); |
| return ((unsigned char) WEXITSTATUS (w)); |
| } |
| else if (!WIFSTOPPED (w)) |
| { |
| fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); |
| clear_inferiors (); |
| *status = 'X'; |
| return ((unsigned char) WTERMSIG (w)); |
| } |
| } |
| else |
| { |
| if (!WIFSTOPPED (w)) |
| goto retry; |
| } |
| |
| *status = 'T'; |
| return ((unsigned char) WSTOPSIG (w)); |
| } |
| |
| static void |
| send_sigstop (struct inferior_list_entry *entry) |
| { |
| struct process_info *process = (struct process_info *) entry; |
| |
| if (process->stopped) |
| return; |
| |
| /* If we already have a pending stop signal for this process, don't |
| send another. */ |
| if (process->stop_expected) |
| { |
| process->stop_expected = 0; |
| return; |
| } |
| |
| if (debug_threads) |
| fprintf (stderr, "Sending sigstop to process %d\n", process->head.id); |
| |
| kill (process->head.id, SIGSTOP); |
| process->sigstop_sent = 1; |
| } |
| |
| static void |
| wait_for_sigstop (struct inferior_list_entry *entry) |
| { |
| struct process_info *process = (struct process_info *) entry; |
| struct thread_info *saved_inferior, *thread; |
| int wstat, saved_tid; |
| |
| if (process->stopped) |
| return; |
| |
| saved_inferior = current_inferior; |
| saved_tid = ((struct inferior_list_entry *) saved_inferior)->id; |
| thread = (struct thread_info *) find_inferior_id (&all_threads, |
| process->tid); |
| wstat = linux_wait_for_event (thread); |
| |
| /* If we stopped with a non-SIGSTOP signal, save it for later |
| and record the pending SIGSTOP. If the process exited, just |
| return. */ |
| if (WIFSTOPPED (wstat) |
| && WSTOPSIG (wstat) != SIGSTOP) |
| { |
| if (debug_threads) |
| fprintf (stderr, "Stopped with non-sigstop signal\n"); |
| process->status_pending_p = 1; |
| process->status_pending = wstat; |
| process->stop_expected = 1; |
| } |
| |
| if (linux_thread_alive (saved_tid)) |
| current_inferior = saved_inferior; |
| else |
| { |
| if (debug_threads) |
| fprintf (stderr, "Previously current thread died.\n"); |
| |
| /* Set a valid thread as current. */ |
| set_desired_inferior (0); |
| } |
| } |
| |
| static void |
| stop_all_processes (void) |
| { |
| stopping_threads = 1; |
| for_each_inferior (&all_processes, send_sigstop); |
| for_each_inferior (&all_processes, wait_for_sigstop); |
| stopping_threads = 0; |
| } |
| |
| /* Resume execution of the inferior process. |
| If STEP is nonzero, single-step it. |
| If SIGNAL is nonzero, give it that signal. */ |
| |
| static void |
| linux_resume_one_process (struct inferior_list_entry *entry, |
| int step, int signal) |
| { |
| struct process_info *process = (struct process_info *) entry; |
| struct thread_info *saved_inferior; |
| |
| if (process->stopped == 0) |
| return; |
| |
| /* If we have pending signals or status, and a new signal, enqueue the |
| signal. Also enqueue the signal if we are waiting to reinsert a |
| breakpoint; it will be picked up again below. */ |
| if (signal != 0 |
| && (process->status_pending_p || process->pending_signals != NULL |
| || process->bp_reinsert != 0)) |
| { |
| struct pending_signals *p_sig; |
| p_sig = malloc (sizeof (*p_sig)); |
| p_sig->prev = process->pending_signals; |
| p_sig->signal = signal; |
| process->pending_signals = p_sig; |
| } |
| |
| if (process->status_pending_p && !check_removed_breakpoint (process)) |
| return; |
| |
| saved_inferior = current_inferior; |
| current_inferior = get_process_thread (process); |
| |
| if (debug_threads) |
| fprintf (stderr, "Resuming process %d (%s, signal %d, stop %s)\n", inferior_pid, |
| step ? "step" : "continue", signal, |
| process->stop_expected ? "expected" : "not expected"); |
| |
| /* This bit needs some thinking about. If we get a signal that |
| we must report while a single-step reinsert is still pending, |
| we often end up resuming the thread. It might be better to |
| (ew) allow a stack of pending events; then we could be sure that |
| the reinsert happened right away and not lose any signals. |
| |
| Making this stack would also shrink the window in which breakpoints are |
| uninserted (see comment in linux_wait_for_process) but not enough for |
| complete correctness, so it won't solve that problem. It may be |
| worthwhile just to solve this one, however. */ |
| if (process->bp_reinsert != 0) |
| { |
| if (debug_threads) |
| fprintf (stderr, " pending reinsert at %08lx", (long)process->bp_reinsert); |
| if (step == 0) |
| fprintf (stderr, "BAD - reinserting but not stepping.\n"); |
| step = 1; |
| |
| /* Postpone any pending signal. It was enqueued above. */ |
| signal = 0; |
| } |
| |
| check_removed_breakpoint (process); |
| |
| if (debug_threads && the_low_target.get_pc != NULL) |
| { |
| fprintf (stderr, " "); |
| (long) (*the_low_target.get_pc) (); |
| } |
| |
| /* If we have pending signals, consume one unless we are trying to reinsert |
| a breakpoint. */ |
| if (process->pending_signals != NULL && process->bp_reinsert == 0) |
| { |
| struct pending_signals **p_sig; |
| |
| p_sig = &process->pending_signals; |
| while ((*p_sig)->prev != NULL) |
| p_sig = &(*p_sig)->prev; |
| |
| signal = (*p_sig)->signal; |
| free (*p_sig); |
| *p_sig = NULL; |
| } |
| |
| regcache_invalidate_one ((struct inferior_list_entry *) |
| get_process_thread (process)); |
| errno = 0; |
| process->stopped = 0; |
| process->stepping = step; |
| ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, process->lwpid, 0, signal); |
| |
| current_inferior = saved_inferior; |
| if (errno) |
| perror_with_name ("ptrace"); |
| } |
| |
| /* This function is called once per process other than the first |
| one. The first process we are told the signal to continue |
| with, and whether to step or continue; for all others, any |
| existing signals will be marked in status_pending_p to be |
| reported momentarily, and we preserve the stepping flag. */ |
| static void |
| linux_continue_one_process (struct inferior_list_entry *entry) |
| { |
| struct process_info *process; |
| |
| process = (struct process_info *) entry; |
| linux_resume_one_process (entry, process->stepping, 0); |
| } |
| |
| static void |
| linux_resume (int step, int signal) |
| { |
| struct process_info *process; |
| |
| process = get_thread_process (current_inferior); |
| |
| /* If the current process has a status pending, this signal will |
| be enqueued and sent later. */ |
| linux_resume_one_process (&process->head, step, signal); |
| |
| if (cont_thread == 0 || cont_thread == -1) |
| for_each_inferior (&all_processes, linux_continue_one_process); |
| } |
| |
| #ifdef HAVE_LINUX_USRREGS |
| |
| int |
| register_addr (int regnum) |
| { |
| int addr; |
| |
| if (regnum < 0 || regnum >= the_low_target.num_regs) |
| error ("Invalid register number %d.", regnum); |
| |
| addr = the_low_target.regmap[regnum]; |
| |
| return addr; |
| } |
| |
| /* Fetch one register. */ |
| static void |
| fetch_register (int regno) |
| { |
| CORE_ADDR regaddr; |
| register int i; |
| char *buf; |
| |
| if (regno >= the_low_target.num_regs) |
| return; |
| if ((*the_low_target.cannot_fetch_register) (regno)) |
| return; |
| |
| regaddr = register_addr (regno); |
| if (regaddr == -1) |
| return; |
| buf = alloca (register_size (regno)); |
| for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| { |
| errno = 0; |
| *(PTRACE_XFER_TYPE *) (buf + i) = |
| ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); |
| regaddr += sizeof (PTRACE_XFER_TYPE); |
| if (errno != 0) |
| { |
| /* Warning, not error, in case we are attached; sometimes the |
| kernel doesn't let us at the registers. */ |
| char *err = strerror (errno); |
| char *msg = alloca (strlen (err) + 128); |
| sprintf (msg, "reading register %d: %s", regno, err); |
| error (msg); |
| goto error_exit; |
| } |
| } |
| supply_register (regno, buf); |
| |
| error_exit:; |
| } |
| |
| /* Fetch all registers, or just one, from the child process. */ |
| static void |
| usr_fetch_inferior_registers (int regno) |
| { |
| if (regno == -1 || regno == 0) |
| for (regno = 0; regno < the_low_target.num_regs; regno++) |
| fetch_register (regno); |
| else |
| fetch_register (regno); |
| } |
| |
| /* Store our register values back into the inferior. |
| If REGNO is -1, do this for all registers. |
| Otherwise, REGNO specifies which register (so we can save time). */ |
| static void |
| usr_store_inferior_registers (int regno) |
| { |
| CORE_ADDR regaddr; |
| int i; |
| char *buf; |
| |
| if (regno >= 0) |
| { |
| if (regno >= the_low_target.num_regs) |
| return; |
| |
| if ((*the_low_target.cannot_store_register) (regno) == 1) |
| return; |
| |
| regaddr = register_addr (regno); |
| if (regaddr == -1) |
| return; |
| errno = 0; |
| buf = alloca (register_size (regno)); |
| collect_register (regno, buf); |
| for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| { |
| errno = 0; |
| ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| *(PTRACE_XFER_TYPE *) (buf + i)); |
| if (errno != 0) |
| { |
| if ((*the_low_target.cannot_store_register) (regno) == 0) |
| { |
| char *err = strerror (errno); |
| char *msg = alloca (strlen (err) + 128); |
| sprintf (msg, "writing register %d: %s", |
| regno, err); |
| error (msg); |
| return; |
| } |
| } |
| regaddr += sizeof (PTRACE_XFER_TYPE); |
| } |
| } |
| else |
| for (regno = 0; regno < the_low_target.num_regs; regno++) |
| usr_store_inferior_registers (regno); |
| } |
| #endif /* HAVE_LINUX_USRREGS */ |
| |
| |
| |
| #ifdef HAVE_LINUX_REGSETS |
| |
| static int |
| regsets_fetch_inferior_registers () |
| { |
| struct regset_info *regset; |
| |
| regset = target_regsets; |
| |
| while (regset->size >= 0) |
| { |
| void *buf; |
| int res; |
| |
| if (regset->size == 0) |
| { |
| regset ++; |
| continue; |
| } |
| |
| buf = malloc (regset->size); |
| res = ptrace (regset->get_request, inferior_pid, 0, buf); |
| if (res < 0) |
| { |
| if (errno == EIO) |
| { |
| /* If we get EIO on the first regset, do not try regsets again. |
| If we get EIO on a later regset, disable that regset. */ |
| if (regset == target_regsets) |
| { |
| use_regsets_p = 0; |
| return -1; |
| } |
| else |
| { |
| regset->size = 0; |
| continue; |
| } |
| } |
| else |
| { |
| char s[256]; |
| sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", |
| inferior_pid); |
| perror (s); |
| } |
| } |
| regset->store_function (buf); |
| regset ++; |
| } |
| return 0; |
| } |
| |
| static int |
| regsets_store_inferior_registers () |
| { |
| struct regset_info *regset; |
| |
| regset = target_regsets; |
| |
| while (regset->size >= 0) |
| { |
| void *buf; |
| int res; |
| |
| if (regset->size == 0) |
| { |
| regset ++; |
| continue; |
| } |
| |
| buf = malloc (regset->size); |
| regset->fill_function (buf); |
| res = ptrace (regset->set_request, inferior_pid, 0, buf); |
| if (res < 0) |
| { |
| if (errno == EIO) |
| { |
| /* If we get EIO on the first regset, do not try regsets again. |
| If we get EIO on a later regset, disable that regset. */ |
| if (regset == target_regsets) |
| { |
| use_regsets_p = 0; |
| return -1; |
| } |
| else |
| { |
| regset->size = 0; |
| continue; |
| } |
| } |
| else |
| { |
| perror ("Warning: ptrace(regsets_store_inferior_registers)"); |
| } |
| } |
| regset ++; |
| free (buf); |
| } |
| return 0; |
| } |
| |
| #endif /* HAVE_LINUX_REGSETS */ |
| |
| |
| void |
| linux_fetch_registers (int regno) |
| { |
| #ifdef HAVE_LINUX_REGSETS |
| if (use_regsets_p) |
| { |
| if (regsets_fetch_inferior_registers () == 0) |
| return; |
| } |
| #endif |
| #ifdef HAVE_LINUX_USRREGS |
| usr_fetch_inferior_registers (regno); |
| #endif |
| } |
| |
| void |
| linux_store_registers (int regno) |
| { |
| #ifdef HAVE_LINUX_REGSETS |
| if (use_regsets_p) |
| { |
| if (regsets_store_inferior_registers () == 0) |
| return; |
| } |
| #endif |
| #ifdef HAVE_LINUX_USRREGS |
| usr_store_inferior_registers (regno); |
| #endif |
| } |
| |
| |
| /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| to debugger memory starting at MYADDR. */ |
| |
| static void |
| linux_read_memory (CORE_ADDR memaddr, char *myaddr, int len) |
| { |
| register int i; |
| /* Round starting address down to longword boundary. */ |
| register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| /* Round ending address up; get number of longwords that makes. */ |
| register int count |
| = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| / sizeof (PTRACE_XFER_TYPE); |
| /* Allocate buffer of that many longwords. */ |
| register PTRACE_XFER_TYPE *buffer |
| = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| |
| /* Read all the longwords */ |
| for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| { |
| buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); |
| } |
| |
| /* Copy appropriate bytes out of the buffer. */ |
| memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); |
| } |
| |
| /* Copy LEN bytes of data from debugger memory at MYADDR |
| to inferior's memory at MEMADDR. |
| On failure (cannot write the inferior) |
| returns the value of errno. */ |
| |
| static int |
| linux_write_memory (CORE_ADDR memaddr, const char *myaddr, int len) |
| { |
| register int i; |
| /* Round starting address down to longword boundary. */ |
| register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| /* Round ending address up; get number of longwords that makes. */ |
| register int count |
| = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); |
| /* Allocate buffer of that many longwords. */ |
| register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| extern int errno; |
| |
| if (debug_threads) |
| { |
| fprintf (stderr, "Writing %02x to %08lx\n", (unsigned)myaddr[0], (long)memaddr); |
| } |
| |
| /* Fill start and end extra bytes of buffer with existing memory data. */ |
| |
| buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
| (PTRACE_ARG3_TYPE) addr, 0); |
| |
| if (count > 1) |
| { |
| buffer[count - 1] |
| = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
| (PTRACE_ARG3_TYPE) (addr + (count - 1) |
| * sizeof (PTRACE_XFER_TYPE)), |
| 0); |
| } |
| |
| /* Copy data to be written over corresponding part of buffer */ |
| |
| memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); |
| |
| /* Write the entire buffer. */ |
| |
| for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| { |
| errno = 0; |
| ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); |
| if (errno) |
| return errno; |
| } |
| |
| return 0; |
| } |
| |
| static void |
| linux_look_up_symbols (void) |
| { |
| #ifdef USE_THREAD_DB |
| if (using_threads) |
| return; |
| |
| using_threads = thread_db_init (); |
| #endif |
| } |
| |
| static void |
| linux_send_signal (int signum) |
| { |
| extern int signal_pid; |
| |
| if (cont_thread > 0) |
| { |
| struct process_info *process; |
| |
| process = get_thread_process (current_inferior); |
| kill (process->lwpid, signum); |
| } |
| else |
| kill (signal_pid, signum); |
| } |
| |
| |
| static struct target_ops linux_target_ops = { |
| linux_create_inferior, |
| linux_attach, |
| linux_kill, |
| linux_detach, |
| linux_thread_alive, |
| linux_resume, |
| linux_wait, |
| linux_fetch_registers, |
| linux_store_registers, |
| linux_read_memory, |
| linux_write_memory, |
| linux_look_up_symbols, |
| linux_send_signal, |
| }; |
| |
| static void |
| linux_init_signals () |
| { |
| /* FIXME drow/2002-06-09: As above, we should check with LinuxThreads |
| to find what the cancel signal actually is. */ |
| signal (__SIGRTMIN+1, SIG_IGN); |
| } |
| |
| void |
| initialize_low (void) |
| { |
| using_threads = 0; |
| set_target_ops (&linux_target_ops); |
| set_breakpoint_data (the_low_target.breakpoint, |
| the_low_target.breakpoint_len); |
| init_registers (); |
| linux_init_signals (); |
| } |