diff options
Diffstat (limited to 'gdb/gdbserver/linux-low.c')
| -rw-r--r-- | gdb/gdbserver/linux-low.c | 875 |
1 files changed, 788 insertions, 87 deletions
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c index 6cfe0d5..c272fed 100644 --- a/gdb/gdbserver/linux-low.c +++ b/gdb/gdbserver/linux-low.c @@ -35,9 +35,32 @@ #include <stdlib.h> #include <unistd.h> -static CORE_ADDR linux_bp_reinsert; +/* ``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 @@ -48,12 +71,64 @@ static int use_regsets_p = 1; extern int errno; -static int inferior_pid; +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; +} -struct inferior_linux_data +static void * +add_process (int pid) { - 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. */ @@ -61,7 +136,7 @@ struct inferior_linux_data static int linux_create_inferior (char *program, char **allargs) { - struct inferior_linux_data *tdata; + void *new_process; int pid; pid = fork (); @@ -72,6 +147,8 @@ linux_create_inferior (char *program, char **allargs) { ptrace (PTRACE_TRACEME, 0, 0, 0); + signal (SIGRTMIN + 1, SIG_DFL); + execv (program, allargs); fprintf (stderr, "Cannot exec %s: %s.\n", program, @@ -80,22 +157,18 @@ linux_create_inferior (char *program, char **allargs) _exit (0177); } - add_inferior (pid); - tdata = (struct inferior_linux_data *) malloc (sizeof (*tdata)); - tdata->pid = pid; - set_inferior_target_data (current_inferior, tdata); + new_process = add_process (pid); + add_thread (pid, new_process); - /* FIXME remove */ - inferior_pid = pid; return 0; } /* Attach to an inferior process. */ -static int -linux_attach (int pid) +void +linux_attach_lwp (int pid, int tid) { - struct inferior_linux_data *tdata; + struct process_info *new_process; if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) { @@ -103,143 +176,712 @@ linux_attach (int pid) errno < sys_nerr ? sys_errlist[errno] : "unknown error", errno); fflush (stderr); - _exit (0177); + + /* If we fail to attach to an LWP, just return. */ + if (!using_threads) + _exit (0177); + return; } - add_inferior (pid); - tdata = (struct inferior_linux_data *) malloc (sizeof (*tdata)); - tdata->pid = pid; - set_inferior_target_data (current_inferior, tdata); + 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 (void) +linux_kill_one_process (struct inferior_list_entry *entry) { - if (inferior_pid == 0) - return; - ptrace (PTRACE_KILL, inferior_pid, 0, 0); - wait (0); - clear_inferiors (); + 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)); } /* Return nonzero if the given thread is still alive. */ +static void +linux_kill (void) +{ + for_each_inferior (&all_threads, linux_kill_one_process); +} + +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 -linux_thread_alive (int pid) +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 -linux_wait_for_one_inferior (struct inferior_info *child) +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) { - struct inferior_linux_data *child_data = inferior_target_data (child); - int pid, wstat; + int ret; + int to_wait_for = -1; + + if (*childp != NULL) + to_wait_for = (*childp)->lwpid; while (1) { - pid = waitpid (child_data->pid, &wstat, 0); + 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 (); + } +} - if (pid != child_data->pid) - perror_with_name ("wait"); +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_breakpoints); 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 this target supports breakpoints, see if we hit one. */ - if (the_low_target.stop_pc != NULL - && WIFSTOPPED (wstat) - && WSTOPSIG (wstat) == SIGTRAP) + if (event_child != NULL) + { + if (event_child->status_pending_p) { - CORE_ADDR stop_pc; + 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"); - if (linux_bp_reinsert != 0) + current_inferior = (struct thread_info *) + find_inferior_id (&all_threads, event_child->tid); + + if (using_threads) + { + /* Check for thread exit. */ + if (! WIFSTOPPED (wstat)) { - reinsert_breakpoint (linux_bp_reinsert); - linux_bp_reinsert = 0; - linux_resume (0, 0); + 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; } - fetch_inferior_registers (0); - stop_pc = (*the_low_target.stop_pc) (); + 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; + } - if (check_breakpoints (stop_pc) != 0) + /* 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 (the_low_target.set_pc != NULL) - (*the_low_target.set_pc) (stop_pc); + 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 (the_low_target.breakpoint_reinsert_addr == NULL) - { - linux_bp_reinsert = stop_pc; - uninsert_breakpoint (stop_pc); - linux_resume (1, 0); - } - else - { - reinsert_breakpoint_by_bp - (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ()); - linux_resume (0, 0); - } + /* If this event was not handled above, and is not a SIGTRAP, report + it. */ + if (!WIFSTOPPED (wstat) || WSTOPSIG (wstat) != SIGTRAP) + return wstat; - continue; + /* 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_breakpoints () 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_breakpoints, 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 */ +/* 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_one_inferior (current_inferior); + w = linux_wait_for_event (child); + stop_all_processes (); disable_async_io (); - if (WIFEXITED (w)) + /* 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) { - fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); - *status = 'W'; - clear_inferiors (); - return ((unsigned char) WEXITSTATUS (w)); + 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)) + else { - fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); - clear_inferiors (); - *status = 'X'; - return ((unsigned char) WTERMSIG (w)); + if (!WIFSTOPPED (w)) + goto retry; } - fetch_inferior_registers (0); - *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 (int step, int signal) +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) + 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; - ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal); + 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; -#ifdef HAVE_LINUX_USRREGS + 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); -#define REGISTER_RAW_SIZE(regno) register_size((regno)) + 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) @@ -262,6 +904,7 @@ fetch_register (int regno) { CORE_ADDR regaddr; register int i; + char *buf; if (regno >= the_low_target.num_regs) return; @@ -271,10 +914,11 @@ fetch_register (int regno) regaddr = register_addr (regno); if (regaddr == -1) return; - for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) + buf = alloca (register_size (regno)); + for (i = 0; i < register_size (regno); i += sizeof (PTRACE_XFER_TYPE)) { errno = 0; - *(PTRACE_XFER_TYPE *) (register_data (regno) + i) = + *(PTRACE_XFER_TYPE *) (buf + i) = ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); regaddr += sizeof (PTRACE_XFER_TYPE); if (errno != 0) @@ -288,6 +932,8 @@ fetch_register (int regno) goto error_exit; } } + supply_register (regno, buf); + error_exit:; } @@ -310,6 +956,7 @@ usr_store_inferior_registers (int regno) { CORE_ADDR regaddr; int i; + char *buf; if (regno >= 0) { @@ -323,11 +970,13 @@ usr_store_inferior_registers (int regno) if (regaddr == -1) return; errno = 0; - for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) + 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, - *(int *) (register_data (regno) + i)); + *(int *) (buf + i)); if (errno != 0) { if ((*the_low_target.cannot_store_register) (regno) == 0) @@ -345,7 +994,7 @@ usr_store_inferior_registers (int regno) } else for (regno = 0; regno < the_low_target.num_regs; regno++) - store_inferior_registers (regno); + usr_store_inferior_registers (regno); } #endif /* HAVE_LINUX_USRREGS */ @@ -354,7 +1003,7 @@ usr_store_inferior_registers (int regno) #ifdef HAVE_LINUX_REGSETS static int -regsets_fetch_inferior_registers (void) +regsets_fetch_inferior_registers () { struct regset_info *regset; @@ -392,7 +1041,10 @@ regsets_fetch_inferior_registers (void) } else { - perror ("Warning: ptrace(regsets_fetch_inferior_registers)"); + char s[256]; + sprintf (s, "ptrace(regsets_fetch_inferior_registers) PID=%d", + inferior_pid); + perror (s); } } regset->store_function (buf); @@ -402,7 +1054,7 @@ regsets_fetch_inferior_registers (void) } static int -regsets_store_inferior_registers (void) +regsets_store_inferior_registers () { struct regset_info *regset; @@ -528,6 +1180,11 @@ linux_write_memory (CORE_ADDR memaddr, const char *myaddr, int len) 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, @@ -562,7 +1219,40 @@ linux_write_memory (CORE_ADDR memaddr, const char *myaddr, int len) static void linux_look_up_symbols (void) { - /* Don't need to look up any symbols yet. */ +#ifdef USE_THREAD_DB + if (using_threads) + return; + + using_threads = thread_db_init (); +#endif +} + +/* Return 1 if this process is not stopped. */ +static int +unstopped_p (struct inferior_list_entry *entry, void *dummy) +{ + struct process_info *process = (struct process_info *) entry; + + if (process->stopped) + return 0; + + return 1; +} + +static int +linux_signal_pid () +{ + struct inferior_list_entry *process; + + process = find_inferior (&all_processes, unstopped_p, NULL); + + if (process == NULL) + { + warning ("no unstopped process"); + return inferior_pid; + } + + return pid_of ((struct process_info *) process); } @@ -578,13 +1268,24 @@ static struct target_ops linux_target_ops = { linux_read_memory, linux_write_memory, linux_look_up_symbols, + linux_signal_pid, }; +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 (); } |