diff options
| -rw-r--r-- | gdb/ChangeLog | 13 | ||||
| -rw-r--r-- | gdb/linux-nat.c | 126 |
2 files changed, 118 insertions, 21 deletions
diff --git a/gdb/ChangeLog b/gdb/ChangeLog index d513cd5..3a5bf3d 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2010-02-08 Pedro Alves <pedro@codesourcery.com> + + * linux-nat.c (linux_nat_resume): In non-stop, also only tag + resumed LWPs as resumed. + (linux_nat_wait_1): If there's no resumed LWP in the set of LWPs + we're waiting for, bail out with TARGET_WAITKIND_IGNORE, instead + of throwing an internal error. If an LWP of a process we're not + waiting for reports a signal, don't force collecting a SIGSTOP, + and if it was breakpoint hit in non-stop mode, cancel it. Don't + go through all LWPs cancelling breakpoints in non-stop mode. + (resume_stopped_resumed_lwps): New. + (linux_nat_wait): Use it. + 2010-02-07 H.J. Lu <hongjiu.lu@intel.com> * features/Makefile (WHICH): Add i386/i386, i386/i386-linux, diff --git a/gdb/linux-nat.c b/gdb/linux-nat.c index 7fc9584..e55d958 100644 --- a/gdb/linux-nat.c +++ b/gdb/linux-nat.c @@ -1912,14 +1912,8 @@ linux_nat_resume (struct target_ops *ops, resume_many = (ptid_equal (minus_one_ptid, ptid) || ptid_is_pid (ptid)); - if (!non_stop) - { - /* Mark the lwps we're resuming as resumed. */ - iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); - iterate_over_lwps (ptid, resume_set_callback, NULL); - } - else - iterate_over_lwps (minus_one_ptid, resume_set_callback, NULL); + /* Mark the lwps we're resuming as resumed. */ + iterate_over_lwps (ptid, resume_set_callback, NULL); /* See if it's the current inferior that should be handled specially. */ @@ -3262,8 +3256,20 @@ retry: lp = NULL; status = 0; - /* Make sure there is at least one LWP that has been resumed. */ - gdb_assert (iterate_over_lwps (ptid, resumed_callback, NULL)); + /* Make sure that of those LWPs we want to get an event from, there + is at least one LWP that has been resumed. If there's none, just + bail out. The core may just be flushing asynchronously all + events. */ + if (iterate_over_lwps (ptid, resumed_callback, NULL) == NULL) + { + ourstatus->kind = TARGET_WAITKIND_IGNORE; + + if (debug_linux_nat_async) + fprintf_unfiltered (gdb_stdlog, "LLW: exit (no resumed LWP)\n"); + + restore_child_signals_mask (&prev_mask); + return minus_one_ptid; + } /* First check if there is a LWP with a wait status pending. */ if (pid == -1) @@ -3394,6 +3400,8 @@ retry: && ptid_is_pid (ptid) && ptid_get_pid (lp->ptid) != ptid_get_pid (ptid)) { + gdb_assert (lp->resumed); + if (debug_linux_nat) fprintf (stderr, "LWP %ld got an event %06x, leaving pending.\n", ptid_get_lwp (lp->ptid), status); @@ -3402,12 +3410,30 @@ retry: { if (WSTOPSIG (lp->status) != SIGSTOP) { - stop_callback (lp, NULL); - - /* Resume in order to collect the sigstop. */ - ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); - - stop_wait_callback (lp, NULL); + /* Cancel breakpoint hits. The breakpoint may + be removed before we fetch events from this + process to report to the core. It is best + not to assume the moribund breakpoints + heuristic always handles these cases --- it + could be too many events go through to the + core before this one is handled. All-stop + always cancels breakpoint hits in all + threads. */ + if (non_stop + && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE + && WSTOPSIG (lp->status) == SIGTRAP + && cancel_breakpoint (lp)) + { + /* Throw away the SIGTRAP. */ + lp->status = 0; + + if (debug_linux_nat) + fprintf (stderr, + "LLW: LWP %ld hit a breakpoint while waiting " + "for another process; cancelled it\n", + ptid_get_lwp (lp->ptid)); + } + lp->stopped = 1; } else { @@ -3597,12 +3623,19 @@ retry: starvation. */ if (pid == -1) select_event_lwp (ptid, &lp, &status); - } - /* Now that we've selected our final event LWP, cancel any - breakpoints in other LWPs that have hit a GDB breakpoint. See - the comment in cancel_breakpoints_callback to find out why. */ - iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); + /* Now that we've selected our final event LWP, cancel any + breakpoints in other LWPs that have hit a GDB breakpoint. + See the comment in cancel_breakpoints_callback to find out + why. */ + iterate_over_lwps (minus_one_ptid, cancel_breakpoints_callback, lp); + + /* In all-stop, from the core's perspective, all LWPs are now + stopped until a new resume action is sent over. */ + iterate_over_lwps (minus_one_ptid, resume_clear_callback, NULL); + } + else + lp->resumed = 0; if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP) { @@ -3628,6 +3661,47 @@ retry: return lp->ptid; } +/* Resume LWPs that are currently stopped without any pending status + to report, but are resumed from the core's perspective. */ + +static int +resume_stopped_resumed_lwps (struct lwp_info *lp, void *data) +{ + ptid_t *wait_ptid_p = data; + + if (lp->stopped + && lp->resumed + && lp->status == 0 + && lp->waitstatus.kind == TARGET_WAITKIND_IGNORE) + { + gdb_assert (is_executing (lp->ptid)); + + /* Don't bother if there's a breakpoint at PC that we'd hit + immediately, and we're not waiting for this LWP. */ + if (!ptid_match (lp->ptid, *wait_ptid_p)) + { + struct regcache *regcache = get_thread_regcache (lp->ptid); + CORE_ADDR pc = regcache_read_pc (regcache); + + if (breakpoint_inserted_here_p (get_regcache_aspace (regcache), pc)) + return 0; + } + + if (debug_linux_nat) + fprintf_unfiltered (gdb_stdlog, + "RSRL: resuming stopped-resumed LWP %s\n", + target_pid_to_str (lp->ptid)); + + linux_ops->to_resume (linux_ops, pid_to_ptid (GET_LWP (lp->ptid)), + lp->step, TARGET_SIGNAL_0); + lp->stopped = 0; + memset (&lp->siginfo, 0, sizeof (lp->siginfo)); + lp->stopped_by_watchpoint = 0; + } + + return 0; +} + static ptid_t linux_nat_wait (struct target_ops *ops, ptid_t ptid, struct target_waitstatus *ourstatus, @@ -3642,6 +3716,16 @@ linux_nat_wait (struct target_ops *ops, if (target_can_async_p ()) async_file_flush (); + /* Resume LWPs that are currently stopped without any pending status + to report, but are resumed from the core's perspective. LWPs get + in this state if we find them stopping at a time we're not + interested in reporting the event (target_wait on a + specific_process, for example, see linux_nat_wait_1), and + meanwhile the event became uninteresting. Don't bother resuming + LWPs we're not going to wait for if they'd stop immediately. */ + if (non_stop) + iterate_over_lwps (minus_one_ptid, resume_stopped_resumed_lwps, &ptid); + event_ptid = linux_nat_wait_1 (ops, ptid, ourstatus, target_options); /* If we requested any event, and something came out, assume there |