/* Low level interface to ptrace, for the remote server for GDB.
Copyright (C) 1995, 1996, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
- 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+ 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
This file is part of GDB.
#include "server.h"
#include "linux-low.h"
-#include "ansidecl.h" /* For ATTRIBUTE_PACKED, must be bug in external.h. */
-#include "elf/common.h"
-#include "elf/external.h"
#include <sys/wait.h>
#include <stdio.h>
#include <dirent.h>
#include <sys/stat.h>
#include <sys/vfs.h>
+#include <sys/uio.h>
+#ifndef ELFMAG0
+/* Don't include <linux/elf.h> here. If it got included by gdb_proc_service.h
+ then ELFMAG0 will have been defined. If it didn't get included by
+ gdb_proc_service.h then including it will likely introduce a duplicate
+ definition of elf_fpregset_t. */
+#include <elf.h>
+#endif
#ifndef SPUFS_MAGIC
#define SPUFS_MAGIC 0x23c9b64e
#define __WALL 0x40000000 /* Wait for any child. */
#endif
+#ifndef W_STOPCODE
+#define W_STOPCODE(sig) ((sig) << 8 | 0x7f)
+#endif
+
#ifdef __UCLIBC__
#if !(defined(__UCLIBC_HAS_MMU__) || defined(__ARCH_HAS_MMU__))
#define HAS_NOMMU
static void linux_resume (struct thread_resume *resume_info, size_t n);
static void stop_all_lwps (void);
static int linux_wait_for_event (ptid_t ptid, int *wstat, int options);
-static int check_removed_breakpoint (struct lwp_info *event_child);
static void *add_lwp (ptid_t ptid);
-static int my_waitpid (int pid, int *status, int flags);
static int linux_stopped_by_watchpoint (void);
static void mark_lwp_dead (struct lwp_info *lwp, int wstat);
+static int linux_core_of_thread (ptid_t ptid);
+static void proceed_all_lwps (void);
+static void unstop_all_lwps (struct lwp_info *except);
+static int finish_step_over (struct lwp_info *lwp);
+static CORE_ADDR get_stop_pc (struct lwp_info *lwp);
+static int kill_lwp (unsigned long lwpid, int signo);
+
+/* True if the low target can hardware single-step. Such targets
+ don't need a BREAKPOINT_REINSERT_ADDR callback. */
+
+static int
+can_hardware_single_step (void)
+{
+ return (the_low_target.breakpoint_reinsert_addr == NULL);
+}
+
+/* True if the low target supports memory breakpoints. If so, we'll
+ have a GET_PC implementation. */
+
+static int
+supports_breakpoints (void)
+{
+ return (the_low_target.get_pc != NULL);
+}
struct pending_signals
{
struct pending_signals *prev;
};
-#define PTRACE_ARG3_TYPE long
+#define PTRACE_ARG3_TYPE void *
+#define PTRACE_ARG4_TYPE void *
#define PTRACE_XFER_TYPE long
#ifdef HAVE_LINUX_REGSETS
/* Return non-zero if HEADER is a 64-bit ELF file. */
static int
-elf_64_header_p (const Elf64_External_Ehdr *header)
+elf_64_header_p (const Elf64_Ehdr *header)
{
return (header->e_ident[EI_MAG0] == ELFMAG0
&& header->e_ident[EI_MAG1] == ELFMAG1
int
elf_64_file_p (const char *file)
{
- Elf64_External_Ehdr header;
+ Elf64_Ehdr header;
int fd;
fd = open (file, O_RDONLY);
return proc;
}
-/* Remove a process from the common process list,
- also freeing all private data. */
-
-static void
-linux_remove_process (struct process_info *process, int detaching)
-{
- struct process_info_private *priv = process->private;
-
-#ifdef USE_THREAD_DB
- thread_db_free (process, detaching);
-#endif
-
- free (priv->arch_private);
- free (priv);
- remove_process (process);
-}
-
/* Wrapper function for waitpid which handles EINTR, and emulates
__WALL for systems where that is not available. */
warning ("wait returned unexpected status 0x%x", status);
}
- ptrace (PTRACE_SETOPTIONS, new_pid, 0, PTRACE_O_TRACECLONE);
+ ptrace (PTRACE_SETOPTIONS, new_pid, 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
ptid = ptid_build (pid_of (event_child), new_pid, 0);
new_lwp = (struct lwp_info *) add_lwp (ptid);
If we do get another signal, be sure not to lose it. */
if (WSTOPSIG (status) == SIGSTOP)
{
- if (! stopping_threads)
+ if (stopping_threads)
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
+ else
linux_resume_one_lwp (new_lwp, 0, 0, NULL);
}
else
{
new_lwp->stop_expected = 1;
+
if (stopping_threads)
{
+ new_lwp->stop_pc = get_stop_pc (new_lwp);
new_lwp->status_pending_p = 1;
new_lwp->status_pending = status;
}
}
}
-/* This function should only be called if the process got a SIGTRAP.
+/* Return the PC as read from the regcache of LWP, without any
+ adjustment. */
+
+static CORE_ADDR
+get_pc (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+ struct regcache *regcache;
+ CORE_ADDR pc;
+
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ regcache = get_thread_regcache (current_inferior, 1);
+ pc = (*the_low_target.get_pc) (regcache);
+
+ if (debug_threads)
+ fprintf (stderr, "pc is 0x%lx\n", (long) pc);
+
+ current_inferior = saved_inferior;
+ return pc;
+}
+
+/* This function should only be called if LWP got a SIGTRAP.
The SIGTRAP could mean several things.
On i386, where decr_pc_after_break is non-zero:
instruction. */
static CORE_ADDR
-get_stop_pc (void)
+get_stop_pc (struct lwp_info *lwp)
{
- CORE_ADDR stop_pc = (*the_low_target.get_pc) ();
+ CORE_ADDR stop_pc;
- if (! get_thread_lwp (current_inferior)->stepping)
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ stop_pc = get_pc (lwp);
+
+ if (WSTOPSIG (lwp->last_status) == SIGTRAP
+ && !lwp->stepping
+ && !lwp->stopped_by_watchpoint
+ && lwp->last_status >> 16 == 0)
stop_pc -= the_low_target.decr_pc_after_break;
if (debug_threads)
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
+#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN + 1, SIG_DFL);
+#endif
setpgid (0, 0);
1) gdbserver has already attached to the process and is being notified
of a new thread that is being created.
- In this case we should ignore that SIGSTOP and resume the process.
- This is handled below by setting stop_expected = 1.
+ In this case we should ignore that SIGSTOP and resume the
+ process. This is handled below by setting stop_expected = 1,
+ and the fact that add_thread sets last_resume_kind ==
+ resume_continue.
2) This is the first thread (the process thread), and we're attaching
to it via attach_inferior.
In this case we want the process thread to stop.
- This is handled by having linux_attach clear stop_expected after
- we return.
+ This is handled by having linux_attach set last_resume_kind ==
+ resume_stop after we return.
??? If the process already has several threads we leave the other
threads running.
because we are guaranteed that the add_lwp call above 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_lwp->stop_expected = 1;
+ new_lwp->stop_expected = 1;
}
void
int
linux_attach (unsigned long pid)
{
- struct lwp_info *lwp;
-
linux_attach_lwp_1 (pid, 1);
-
linux_add_process (pid, 1);
if (!non_stop)
{
- /* Don't ignore the initial SIGSTOP if we just attached to this
- process. It will be collected by wait shortly. */
- lwp = (struct lwp_info *) find_inferior_id (&all_lwps,
- ptid_build (pid, pid, 0));
- lwp->stop_expected = 0;
+ struct thread_info *thread;
+
+ /* Don't ignore the initial SIGSTOP if we just attached to this
+ process. It will be collected by wait shortly. */
+ thread = find_thread_ptid (ptid_build (pid, pid, 0));
+ thread->last_resume_kind = resume_stop;
}
return 0;
} while (lwpid > 0 && WIFSTOPPED (wstat));
delete_lwp (lwp);
- linux_remove_process (process, 0);
+
+ the_target->mourn (process);
return 0;
}
return 0;
}
- /* Make sure the process isn't stopped at a breakpoint that's
- no longer there. */
- check_removed_breakpoint (lwp);
-
/* If this process is stopped but is expecting a SIGSTOP, then make
sure we take care of that now. This isn't absolutely guaranteed
to collect the SIGSTOP, but is fairly likely to. */
if (process == NULL)
return -1;
+#ifdef USE_THREAD_DB
+ thread_db_detach (process);
+#endif
+
current_inferior =
(struct thread_info *) find_inferior (&all_threads, any_thread_of, &pid);
delete_all_breakpoints ();
find_inferior (&all_threads, linux_detach_one_lwp, &pid);
- linux_remove_process (process, 1);
+
+ the_target->mourn (process);
return 0;
}
+static void
+linux_mourn (struct process_info *process)
+{
+ struct process_info_private *priv;
+
+#ifdef USE_THREAD_DB
+ thread_db_mourn (process);
+#endif
+
+ /* Freeing all private data. */
+ priv = process->private;
+ free (priv->arch_private);
+ free (priv);
+ process->private = NULL;
+}
+
static void
linux_join (int pid)
{
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 lwp_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 in lwp %ld.\n",
- lwpid_of (event_child));
-
- saved_inferior = current_inferior;
- current_inferior = get_lwp_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. Old PC was 0x%08llx\n",
- event_child->pending_stop_pc);
-
- 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)
- {
- if (debug_threads)
- fprintf (stderr, "Set pc to 0x%lx\n", (long) stop_pc);
- (*the_low_target.set_pc) (stop_pc);
- }
-
- /* We consumed the pending SIGTRAP. */
- event_child->pending_is_breakpoint = 0;
- event_child->status_pending_p = 0;
- event_child->status_pending = 0;
-
- current_inferior = saved_inferior;
- return 1;
-}
-
-/* Return 1 if this lwp has an interesting status pending. This
- function may silently resume an inferior lwp. */
+/* Return 1 if this lwp has an interesting status pending. */
static int
-status_pending_p (struct inferior_list_entry *entry, void *arg)
+status_pending_p_callback (struct inferior_list_entry *entry, void *arg)
{
struct lwp_info *lwp = (struct lwp_info *) entry;
ptid_t ptid = * (ptid_t *) arg;
+ struct thread_info *thread = get_lwp_thread (lwp);
/* Check if we're only interested in events from a specific process
or its lwps. */
&& ptid_get_pid (ptid) != ptid_get_pid (lwp->head.id))
return 0;
- if (lwp->status_pending_p && !lwp->suspended)
- if (check_removed_breakpoint (lwp))
- {
- /* 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_lwp (lwp, 0, 0, NULL);
- return 0;
- }
+ thread = get_lwp_thread (lwp);
+
+ /* If we got a `vCont;t', but we haven't reported a stop yet, do
+ report any status pending the LWP may have. */
+ if (thread->last_resume_kind == resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_STOPPED)
+ return 0;
- return (lwp->status_pending_p && !lwp->suspended);
+ return lwp->status_pending_p;
}
static int
goto retry;
child->stopped = 1;
- child->pending_is_breakpoint = 0;
child->last_status = *wstatp;
new_inferior = 0;
}
+ /* Fetch the possibly triggered data watchpoint info and store it in
+ CHILD.
+
+ On some archs, like x86, that use debug registers to set
+ watchpoints, it's possible that the way to know which watched
+ address trapped, is to check the register that is used to select
+ which address to watch. Problem is, between setting the
+ watchpoint and reading back which data address trapped, the user
+ may change the set of watchpoints, and, as a consequence, GDB
+ changes the debug registers in the inferior. To avoid reading
+ back a stale stopped-data-address when that happens, we cache in
+ LP the fact that a watchpoint trapped, and the corresponding data
+ address, as soon as we see CHILD stop with a SIGTRAP. If GDB
+ changes the debug registers meanwhile, we have the cached data we
+ can rely on. */
+
+ if (WIFSTOPPED (*wstatp) && WSTOPSIG (*wstatp) == SIGTRAP)
+ {
+ if (the_low_target.stopped_by_watchpoint == NULL)
+ {
+ child->stopped_by_watchpoint = 0;
+ }
+ else
+ {
+ struct thread_info *saved_inferior;
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (child);
+
+ child->stopped_by_watchpoint
+ = the_low_target.stopped_by_watchpoint ();
+
+ if (child->stopped_by_watchpoint)
+ {
+ if (the_low_target.stopped_data_address != NULL)
+ child->stopped_data_address
+ = the_low_target.stopped_data_address ();
+ else
+ child->stopped_data_address = 0;
+ }
+
+ current_inferior = saved_inferior;
+ }
+ }
+
+ /* Store the STOP_PC, with adjustment applied. This depends on the
+ architecture being defined already (so that CHILD has a valid
+ regcache), and on LAST_STATUS being set (to check for SIGTRAP or
+ not). */
+ if (WIFSTOPPED (*wstatp))
+ child->stop_pc = get_stop_pc (child);
+
if (debug_threads
&& WIFSTOPPED (*wstatp)
&& the_low_target.get_pc != NULL)
{
struct thread_info *saved_inferior = current_inferior;
+ struct regcache *regcache;
CORE_ADDR pc;
- current_inferior = (struct thread_info *)
- find_inferior_id (&all_threads, child->head.id);
- pc = (*the_low_target.get_pc) ();
+ current_inferior = get_lwp_thread (child);
+ regcache = get_thread_regcache (current_inferior, 1);
+ pc = (*the_low_target.get_pc) (regcache);
fprintf (stderr, "linux_wait_for_lwp: pc is 0x%lx\n", (long) pc);
current_inferior = saved_inferior;
}
return child;
}
+/* This function should only be called if the LWP got a SIGTRAP.
+
+ Handle any tracepoint steps or hits. Return true if a tracepoint
+ event was handled, 0 otherwise. */
+
+static int
+handle_tracepoints (struct lwp_info *lwp)
+{
+ struct thread_info *tinfo = get_lwp_thread (lwp);
+ int tpoint_related_event = 0;
+
+ /* And we need to be sure that any all-threads-stopping doesn't try
+ to move threads out of the jump pads, as it could deadlock the
+ inferior (LWP could be in the jump pad, maybe even holding the
+ lock.) */
+
+ /* Do any necessary step collect actions. */
+ tpoint_related_event |= tracepoint_finished_step (tinfo, lwp->stop_pc);
+
+ /* See if we just hit a tracepoint and do its main collect
+ actions. */
+ tpoint_related_event |= tracepoint_was_hit (tinfo, lwp->stop_pc);
+
+ if (tpoint_related_event)
+ {
+ if (debug_threads)
+ fprintf (stderr, "got a tracepoint event\n");
+ return 1;
+ }
+
+ return 0;
+}
+
+/* Arrange for a breakpoint to be hit again later. We don't keep the
+ SIGTRAP status and don't forward the SIGTRAP signal to the LWP. We
+ will handle the current event, eventually we will resume this LWP,
+ and this breakpoint will trap again. */
+
+static int
+cancel_breakpoint (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+
+ /* There's nothing to do if we don't support breakpoints. */
+ if (!supports_breakpoints ())
+ return 0;
+
+ /* breakpoint_at reads from current inferior. */
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ if ((*the_low_target.breakpoint_at) (lwp->stop_pc))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: Push back breakpoint for %s\n",
+ target_pid_to_str (ptid_of (lwp)));
+
+ /* Back up the PC if necessary. */
+ if (the_low_target.decr_pc_after_break)
+ {
+ struct regcache *regcache
+ = get_thread_regcache (current_inferior, 1);
+ (*the_low_target.set_pc) (regcache, lwp->stop_pc);
+ }
+
+ current_inferior = saved_inferior;
+ return 1;
+ }
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "CB: No breakpoint found at %s for [%s]\n",
+ paddress (lwp->stop_pc),
+ target_pid_to_str (ptid_of (lwp)));
+ }
+
+ current_inferior = saved_inferior;
+ return 0;
+}
+
+/* When the event-loop is doing a step-over, this points at the thread
+ being stepped. */
+ptid_t step_over_bkpt;
+
/* Wait for an event from child PID. If PID is -1, wait for any
child. Store the stop status through the status pointer WSTAT.
OPTIONS is passed to the waitpid call. Return 0 if no child stop
static int
linux_wait_for_event_1 (ptid_t ptid, int *wstat, int options)
{
- CORE_ADDR stop_pc;
- struct lwp_info *event_child = NULL;
- int bp_status;
- struct lwp_info *requested_child = NULL;
+ struct lwp_info *event_child, *requested_child;
+
+ event_child = NULL;
+ requested_child = NULL;
/* Check for a lwp 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 (ptid_equal (ptid, minus_one_ptid)
|| ptid_equal (pid_to_ptid (ptid_get_pid (ptid)), ptid))
{
event_child = (struct lwp_info *)
- find_inferior (&all_lwps, status_pending_p, &ptid);
+ find_inferior (&all_lwps, status_pending_p_callback, &ptid);
if (debug_threads && event_child)
fprintf (stderr, "Got a pending child %ld\n", lwpid_of (event_child));
}
else
{
requested_child = find_lwp_pid (ptid);
- if (requested_child->status_pending_p
- && !check_removed_breakpoint (requested_child))
+
+ if (requested_child->status_pending_p)
event_child = requested_child;
}
event_child = linux_wait_for_lwp (ptid, wstat, options);
if ((options & WNOHANG) && event_child == NULL)
- return 0;
+ {
+ if (debug_threads)
+ fprintf (stderr, "WNOHANG set, no event found\n");
+ return 0;
+ }
if (event_child == NULL)
error ("event from unknown child");
return lwpid_of (event_child);
}
- delete_lwp (event_child);
-
if (!non_stop)
{
current_inferior = (struct thread_info *) all_threads.head;
/* If we were waiting for this particular child to do something...
well, it did something. */
if (requested_child != NULL)
- return lwpid_of (event_child);
+ {
+ int lwpid = lwpid_of (event_child);
+
+ /* Cancel the step-over operation --- the thread that
+ started it is gone. */
+ if (finish_step_over (event_child))
+ unstop_all_lwps (event_child);
+ delete_lwp (event_child);
+ return lwpid;
+ }
+
+ delete_lwp (event_child);
/* Wait for a more interesting event. */
continue;
if (event_child->must_set_ptrace_flags)
{
ptrace (PTRACE_SETOPTIONS, lwpid_of (event_child),
- 0, PTRACE_O_TRACECLONE);
+ 0, (PTRACE_ARG4_TYPE) PTRACE_O_TRACECLONE);
event_child->must_set_ptrace_flags = 0;
}
- 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_lwp (event_child, event_child->stepping, 0, NULL);
- continue;
- }
-
if (WIFSTOPPED (*wstat) && WSTOPSIG (*wstat) == SIGTRAP
&& *wstat >> 16 != 0)
{
if (WIFSTOPPED (*wstat)
&& !event_child->stepping
&& (
-#ifdef USE_THREAD_DB
+#if defined (USE_THREAD_DB) && defined (__SIGRTMIN)
(current_process ()->private->thread_db != NULL
&& (WSTOPSIG (*wstat) == __SIGRTMIN
|| WSTOPSIG (*wstat) == __SIGRTMIN + 1))
||
#endif
(pass_signals[target_signal_from_host (WSTOPSIG (*wstat))]
- && (WSTOPSIG (*wstat) != SIGSTOP || !stopping_threads))))
+ && !(WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected))))
{
siginfo_t info, *info_p;
info_p = &info;
else
info_p = NULL;
- linux_resume_one_lwp (event_child,
- event_child->stepping,
+ linux_resume_one_lwp (event_child, event_child->stepping,
WSTOPSIG (*wstat), info_p);
continue;
}
- /* If this event was not handled above, and is not a SIGTRAP, report
- it. */
- if (!WIFSTOPPED (*wstat) || WSTOPSIG (*wstat) != SIGTRAP)
- return lwpid_of (event_child);
-
- /* 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 lwpid_of (event_child);
-
- 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 (WIFSTOPPED (*wstat)
+ && WSTOPSIG (*wstat) == SIGSTOP
+ && event_child->stop_expected)
{
- 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_lwp (event_child, 0, 0, NULL);
- continue;
- }
+ int should_stop;
- bp_status = check_breakpoints (stop_pc);
-
- if (bp_status != 0)
- {
if (debug_threads)
- fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ fprintf (stderr, "Expected stop.\n");
+ event_child->stop_expected = 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;
-
- /* We may 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. */
+ should_stop = (current_inferior->last_resume_kind == resume_stop
+ || stopping_threads);
- /* NOTE: we're lifting breakpoints in non-stop mode. This
- is currently only used for thread event breakpoints, so
- it isn't that bad as long as we have PTRACE_EVENT_CLONE
- events. */
- if (bp_status == 2)
- /* No need to reinsert. */
- linux_resume_one_lwp (event_child, 0, 0, NULL);
- else if (the_low_target.breakpoint_reinsert_addr == NULL)
- {
- event_child->bp_reinsert = stop_pc;
- uninsert_breakpoint (stop_pc);
- linux_resume_one_lwp (event_child, 1, 0, NULL);
- }
- else
+ if (!should_stop)
{
- reinsert_breakpoint_by_bp
- (stop_pc, (*the_low_target.breakpoint_reinsert_addr) ());
- linux_resume_one_lwp (event_child, 0, 0, NULL);
+ linux_resume_one_lwp (event_child,
+ event_child->stepping, 0, NULL);
+ continue;
}
-
- continue;
- }
-
- if (debug_threads)
- fprintf (stderr, "Hit a non-gdbserver breakpoint.\n");
-
- /* If we were single-stepping, we definitely want to report the
- SIGTRAP. Although the single-step operation has completed,
- do not clear clear the stepping flag yet; we need to check it
- in wait_for_sigstop. */
- if (event_child->stepping)
- return lwpid_of (event_child);
-
- /* 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 lwpid_of (event_child);
}
}
+
+/* Count the LWP's that have had events. */
+
+static int
+count_events_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ int *count = data;
+
+ gdb_assert (count != NULL);
+
+ /* Count only resumed LWPs that have a SIGTRAP event pending that
+ should be reported to GDB. */
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && thread->last_resume_kind != resume_stop
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !breakpoint_inserted_here (lp->stop_pc))
+ (*count)++;
+
+ return 0;
+}
+
+/* Select the LWP (if any) that is currently being single-stepped. */
+
+static int
+select_singlestep_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+
+ if (thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && thread->last_resume_kind == resume_step
+ && lp->status_pending_p)
+ return 1;
+ else
+ return 0;
+}
+
+/* Select the Nth LWP that has had a SIGTRAP event that should be
+ reported to GDB. */
+
+static int
+select_event_lwp_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ int *selector = data;
+
+ gdb_assert (selector != NULL);
+
+ /* Select only resumed LWPs that have a SIGTRAP event pending. */
+ if (thread->last_resume_kind != resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !breakpoint_inserted_here (lp->stop_pc))
+ if ((*selector)-- == 0)
+ return 1;
+
+ return 0;
+}
+
+static int
+cancel_breakpoints_callback (struct inferior_list_entry *entry, void *data)
+{
+ struct lwp_info *lp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lp);
+ struct lwp_info *event_lp = data;
+
+ /* Leave the LWP that has been elected to receive a SIGTRAP alone. */
+ if (lp == event_lp)
+ return 0;
+
+ /* If a LWP other than the LWP that we're reporting an event for has
+ hit a GDB breakpoint (as opposed to some random trap signal),
+ then just arrange for it to hit it again later. We don't keep
+ the SIGTRAP status and don't forward the SIGTRAP signal to the
+ LWP. We will handle the current event, eventually we will resume
+ all LWPs, and this one will get its breakpoint trap again.
+
+ If we do not do this, then we run the risk that the user will
+ delete or disable the breakpoint, but the LWP will have already
+ tripped on it. */
+
+ if (thread->last_resume_kind != resume_stop
+ && thread->last_status.kind == TARGET_WAITKIND_IGNORE
+ && lp->status_pending_p
+ && WIFSTOPPED (lp->status_pending)
+ && WSTOPSIG (lp->status_pending) == SIGTRAP
+ && !lp->stepping
+ && !lp->stopped_by_watchpoint
+ && cancel_breakpoint (lp))
+ /* Throw away the SIGTRAP. */
+ lp->status_pending_p = 0;
+
+ return 0;
+}
+
+/* Select one LWP out of those that have events pending. */
+
+static void
+select_event_lwp (struct lwp_info **orig_lp)
+{
+ int num_events = 0;
+ int random_selector;
+ struct lwp_info *event_lp;
+
+ /* Give preference to any LWP that is being single-stepped. */
+ event_lp
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ select_singlestep_lwp_callback, NULL);
+ if (event_lp != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "SEL: Select single-step %s\n",
+ target_pid_to_str (ptid_of (event_lp)));
+ }
+ else
+ {
+ /* No single-stepping LWP. Select one at random, out of those
+ which have had SIGTRAP events. */
+
+ /* First see how many SIGTRAP events we have. */
+ find_inferior (&all_lwps, count_events_callback, &num_events);
+
+ /* Now randomly pick a LWP out of those that have had a SIGTRAP. */
+ random_selector = (int)
+ ((num_events * (double) rand ()) / (RAND_MAX + 1.0));
+
+ if (debug_threads && num_events > 1)
+ fprintf (stderr,
+ "SEL: Found %d SIGTRAP events, selecting #%d\n",
+ num_events, random_selector);
+
+ event_lp = (struct lwp_info *) find_inferior (&all_lwps,
+ select_event_lwp_callback,
+ &random_selector);
+ }
+
+ if (event_lp != NULL)
+ {
+ /* Switch the event LWP. */
+ *orig_lp = event_lp;
+ }
+}
+
+/* Set this inferior LWP's state as "want-stopped". We won't resume
+ this LWP until the client gives us another action for it. */
+
+static void
+gdb_wants_lwp_stopped (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread = get_lwp_thread (lwp);
+
+ /* Most threads are stopped implicitly (all-stop); tag that with
+ signal 0. The thread being explicitly reported stopped to the
+ client, gets it's status fixed up afterwards. */
+ thread->last_status.kind = TARGET_WAITKIND_STOPPED;
+ thread->last_status.value.sig = TARGET_SIGNAL_0;
+
+ thread->last_resume_kind = resume_stop;
+}
+
+/* Set all LWP's states as "want-stopped". */
+
+static void
+gdb_wants_all_stopped (void)
+{
+ for_each_inferior (&all_lwps, gdb_wants_lwp_stopped);
+}
+
/* Wait for process, returns status. */
static ptid_t
struct target_waitstatus *ourstatus, int target_options)
{
int w;
- struct thread_info *thread = NULL;
- struct lwp_info *lwp = NULL;
+ struct lwp_info *event_child;
int options;
int pid;
+ int step_over_finished;
+ int bp_explains_trap;
+ int maybe_internal_trap;
+ int report_to_gdb;
+ int trace_event;
/* Translate generic target options into linux options. */
options = __WALL;
&& !ptid_equal (cont_thread, null_ptid)
&& !ptid_equal (cont_thread, minus_one_ptid))
{
+ struct thread_info *thread;
+
thread = (struct thread_info *) find_inferior_id (&all_threads,
cont_thread);
ptid = cont_thread;
}
- pid = linux_wait_for_event (ptid, &w, options);
+ if (ptid_equal (step_over_bkpt, null_ptid))
+ pid = linux_wait_for_event (ptid, &w, options);
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr, "step_over_bkpt set [%s], doing a blocking wait\n",
+ target_pid_to_str (step_over_bkpt));
+ pid = linux_wait_for_event (step_over_bkpt, &w, options & ~WNOHANG);
+ }
+
if (pid == 0) /* only if TARGET_WNOHANG */
return null_ptid;
- lwp = get_thread_lwp (current_inferior);
+ event_child = get_thread_lwp (current_inferior);
/* If we are waiting for a particular child, and it exited,
linux_wait_for_event will return its exit status. Similarly if
{
if (WIFEXITED (w) || WIFSIGNALED (w))
{
- int pid = pid_of (lwp);
- struct process_info *process = find_process_pid (pid);
-
- delete_lwp (lwp);
- linux_remove_process (process, 0);
+ delete_lwp (event_child);
current_inferior = NULL;
goto retry;
}
- /* In all-stop, stop all threads. Be careful to only do this if
- we're about to report an event to GDB. */
+ /* If this event was not handled before, and is not a SIGTRAP, we
+ report it. SIGILL and SIGSEGV are also treated as traps in case
+ a breakpoint is inserted at the current PC. If this target does
+ not support internal breakpoints at all, we also report the
+ SIGTRAP without further processing; it's of no concern to us. */
+ maybe_internal_trap
+ = (supports_breakpoints ()
+ && (WSTOPSIG (w) == SIGTRAP
+ || ((WSTOPSIG (w) == SIGILL
+ || WSTOPSIG (w) == SIGSEGV)
+ && (*the_low_target.breakpoint_at) (event_child->stop_pc))));
+
+ if (maybe_internal_trap)
+ {
+ /* Handle anything that requires bookkeeping before deciding to
+ report the event or continue waiting. */
+
+ /* First check if we can explain the SIGTRAP with an internal
+ breakpoint, or if we should possibly report the event to GDB.
+ Do this before anything that may remove or insert a
+ breakpoint. */
+ bp_explains_trap = breakpoint_inserted_here (event_child->stop_pc);
+
+ /* We have a SIGTRAP, possibly a step-over dance has just
+ finished. If so, tweak the state machine accordingly,
+ reinsert breakpoints and delete any reinsert (software
+ single-step) breakpoints. */
+ step_over_finished = finish_step_over (event_child);
+
+ /* Now invoke the callbacks of any internal breakpoints there. */
+ check_breakpoints (event_child->stop_pc);
+
+ /* Handle tracepoint data collecting. This may overflow the
+ trace buffer, and cause a tracing stop, removing
+ breakpoints. */
+ trace_event = handle_tracepoints (event_child);
+
+ if (bp_explains_trap)
+ {
+ /* If we stepped or ran into an internal breakpoint, we've
+ already handled it. So next time we resume (from this
+ PC), we should step over it. */
+ if (debug_threads)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+
+ if (breakpoint_here (event_child->stop_pc))
+ event_child->need_step_over = 1;
+ }
+ }
+ else
+ {
+ /* We have some other signal, possibly a step-over dance was in
+ progress, and it should be cancelled too. */
+ step_over_finished = finish_step_over (event_child);
+
+ trace_event = 0;
+ }
+
+ /* We have all the data we need. Either report the event to GDB, or
+ resume threads and keep waiting for more. */
+
+ /* Check If GDB would be interested in this event. If GDB wanted
+ this thread to single step, we always want to report the SIGTRAP,
+ and let GDB handle it. Watchpoints should always be reported.
+ So should signals we can't explain. A SIGTRAP we can't explain
+ could be a GDB breakpoint --- we may or not support Z0
+ breakpoints. If we do, we're be able to handle GDB breakpoints
+ on top of internal breakpoints, by handling the internal
+ breakpoint and still reporting the event to GDB. If we don't,
+ we're out of luck, GDB won't see the breakpoint hit. */
+ report_to_gdb = (!maybe_internal_trap
+ || current_inferior->last_resume_kind == resume_step
+ || event_child->stopped_by_watchpoint
+ || (!step_over_finished && !bp_explains_trap && !trace_event)
+ || gdb_breakpoint_here (event_child->stop_pc));
+
+ /* We found no reason GDB would want us to stop. We either hit one
+ of our own breakpoints, or finished an internal step GDB
+ shouldn't know about. */
+ if (!report_to_gdb)
+ {
+ if (debug_threads)
+ {
+ if (bp_explains_trap)
+ fprintf (stderr, "Hit a gdbserver breakpoint.\n");
+ if (step_over_finished)
+ fprintf (stderr, "Step-over finished.\n");
+ if (trace_event)
+ fprintf (stderr, "Tracepoint event.\n");
+ }
+
+ /* We're not reporting this breakpoint to GDB, so apply the
+ decr_pc_after_break adjustment to the inferior's regcache
+ ourselves. */
+
+ if (the_low_target.set_pc != NULL)
+ {
+ struct regcache *regcache
+ = get_thread_regcache (get_lwp_thread (event_child), 1);
+ (*the_low_target.set_pc) (regcache, event_child->stop_pc);
+ }
+
+ /* We've finished stepping over a breakpoint. We've stopped all
+ LWPs momentarily except the stepping one. This is where we
+ resume them all again. We're going to keep waiting, so use
+ proceed, which handles stepping over the next breakpoint. */
+ if (debug_threads)
+ fprintf (stderr, "proceeding all threads.\n");
+ proceed_all_lwps ();
+ goto retry;
+ }
+
+ if (debug_threads)
+ {
+ if (current_inferior->last_resume_kind == resume_step)
+ fprintf (stderr, "GDB wanted to single-step, reporting event.\n");
+ if (event_child->stopped_by_watchpoint)
+ fprintf (stderr, "Stopped by watchpoint.\n");
+ if (gdb_breakpoint_here (event_child->stop_pc))
+ fprintf (stderr, "Stopped by GDB breakpoint.\n");
+ if (debug_threads)
+ fprintf (stderr, "Hit a non-gdbserver trap event.\n");
+ }
+
+ /* Alright, we're going to report a stop. */
+
if (!non_stop)
- stop_all_lwps ();
+ {
+ /* In all-stop, stop all threads. */
+ stop_all_lwps ();
+
+ /* If we're not waiting for a specific LWP, choose an event LWP
+ from among those that have had events. Giving equal priority
+ to all LWPs that have had events helps prevent
+ starvation. */
+ if (ptid_equal (ptid, minus_one_ptid))
+ {
+ event_child->status_pending_p = 1;
+ event_child->status_pending = w;
+
+ select_event_lwp (&event_child);
+
+ event_child->status_pending_p = 0;
+ w = event_child->status_pending;
+ }
+
+ /* 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. */
+ find_inferior (&all_lwps, cancel_breakpoints_callback, event_child);
+ }
+ else
+ {
+ /* If we just finished a step-over, then all threads had been
+ momentarily paused. In all-stop, that's fine, we want
+ threads stopped by now anyway. In non-stop, we need to
+ re-resume threads that GDB wanted to be running. */
+ if (step_over_finished)
+ unstop_all_lwps (event_child);
+ }
ourstatus->kind = TARGET_WAITKIND_STOPPED;
- if (lwp->suspended && WSTOPSIG (w) == SIGSTOP)
+ /* Do this before the gdb_wants_all_stopped calls below, since they
+ always set last_resume_kind to resume_stop. */
+ if (current_inferior->last_resume_kind == resume_stop
+ && WSTOPSIG (w) == SIGSTOP)
{
/* A thread that has been requested to stop by GDB with vCont;t,
and it stopped cleanly, so report as SIG0. The use of
SIGSTOP is an implementation detail. */
ourstatus->value.sig = TARGET_SIGNAL_0;
}
- else if (lwp->suspended && WSTOPSIG (w) != SIGSTOP)
+ else if (current_inferior->last_resume_kind == resume_stop
+ && WSTOPSIG (w) != SIGSTOP)
{
/* A thread that has been requested to stop by GDB with vCont;t,
- but, it stopped for other reasons. Set stop_expected so the
- pending SIGSTOP is ignored and the LWP is resumed. */
- lwp->stop_expected = 1;
+ but, it stopped for other reasons. */
ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
}
else
ourstatus->value.sig = target_signal_from_host (WSTOPSIG (w));
}
+ gdb_assert (ptid_equal (step_over_bkpt, null_ptid));
+
+ if (!non_stop)
+ {
+ /* From GDB's perspective, all-stop mode always stops all
+ threads implicitly. Tag all threads as "want-stopped". */
+ gdb_wants_all_stopped ();
+ }
+ else
+ {
+ /* We're reporting this LWP as stopped. Update it's
+ "want-stopped" state to what the client wants, until it gets
+ a new resume action. */
+ gdb_wants_lwp_stopped (&event_child->head);
+ }
+
if (debug_threads)
fprintf (stderr, "linux_wait ret = %s, %d, %d\n",
- target_pid_to_str (lwp->head.id),
+ target_pid_to_str (ptid_of (event_child)),
ourstatus->kind,
ourstatus->value.sig);
- return lwp->head.id;
+ get_lwp_thread (event_child)->last_status = *ourstatus;
+ return ptid_of (event_child);
}
/* Get rid of any pending event in the pipe. */
return event_ptid;
}
-/* Send a signal to an LWP. For LinuxThreads, kill is enough; however, if
- thread groups are in use, we need to use tkill. */
+/* Send a signal to an LWP. */
static int
kill_lwp (unsigned long lwpid, int signo)
{
- static int tkill_failed;
+ /* Use tkill, if possible, in case we are using nptl threads. If tkill
+ fails, then we are not using nptl threads and we should be using kill. */
- errno = 0;
+#ifdef __NR_tkill
+ {
+ static int tkill_failed;
-#ifdef SYS_tkill
- if (!tkill_failed)
- {
- int ret = syscall (SYS_tkill, lwpid, signo);
- if (errno != ENOSYS)
- return ret;
- errno = 0;
- tkill_failed = 1;
- }
+ if (!tkill_failed)
+ {
+ int ret;
+
+ errno = 0;
+ ret = syscall (__NR_tkill, lwpid, signo);
+ if (errno != ENOSYS)
+ return ret;
+ tkill_failed = 1;
+ }
+ }
#endif
return kill (lwpid, signo);
if (debug_threads)
fprintf (stderr, "Have pending sigstop for lwp %d\n", pid);
- /* We clear the stop_expected flag so that wait_for_sigstop
- will receive the SIGSTOP event (instead of silently resuming and
- waiting again). It'll be reset below. */
- lwp->stop_expected = 0;
return;
}
if (debug_threads)
fprintf (stderr, "Sending sigstop to lwp %d\n", pid);
+ lwp->stop_expected = 1;
kill_lwp (pid, SIGSTOP);
}
lwp->status_pending_p = 1;
lwp->status_pending = wstat;
- /* So that check_removed_breakpoint doesn't try to figure out if
- this is stopped at a breakpoint. */
- lwp->pending_is_breakpoint = 0;
-
/* Prevent trying to stop it. */
lwp->stopped = 1;
int wstat;
ptid_t saved_tid;
ptid_t ptid;
+ int pid;
if (lwp->stopped)
- return;
+ {
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: LWP %ld already stopped\n",
+ lwpid_of (lwp));
+ return;
+ }
saved_inferior = current_inferior;
if (saved_inferior != NULL)
ptid = lwp->head.id;
- linux_wait_for_event (ptid, &wstat, __WALL);
+ if (debug_threads)
+ fprintf (stderr, "wait_for_sigstop: pulling one event\n");
+
+ pid = linux_wait_for_event (ptid, &wstat, __WALL);
/* 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 (WIFSTOPPED (wstat))
{
if (debug_threads)
- fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
- lwpid_of (lwp), wstat);
-
- /* Do not leave a pending single-step finish to be reported to
- the client. The client will give us a new action for this
- thread, possibly a continue request --- otherwise, the client
- would consider this pending SIGTRAP reported later a spurious
- signal. */
- if (WSTOPSIG (wstat) == SIGTRAP
- && lwp->stepping
- && !linux_stopped_by_watchpoint ())
+ fprintf (stderr, "LWP %ld stopped with signal %d\n",
+ lwpid_of (lwp), WSTOPSIG (wstat));
+
+ if (WSTOPSIG (wstat) != SIGSTOP)
{
if (debug_threads)
- fprintf (stderr, " single-step SIGTRAP ignored\n");
- }
- else
- {
+ fprintf (stderr, "LWP %ld stopped with non-sigstop status %06x\n",
+ lwpid_of (lwp), wstat);
+
lwp->status_pending_p = 1;
lwp->status_pending = wstat;
}
- lwp->stop_expected = 1;
}
- else if (!WIFSTOPPED (wstat))
+ else
{
if (debug_threads)
- fprintf (stderr, "Process %ld exited while stopping LWPs\n",
- lwpid_of (lwp));
+ fprintf (stderr, "Process %d exited while stopping LWPs\n", pid);
- /* Leave this status pending for the next time we're able to
- report it. In the mean time, we'll report this lwp as dead
- to GDB, so GDB doesn't try to read registers and memory from
- it. */
- mark_lwp_dead (lwp, wstat);
+ lwp = find_lwp_pid (pid_to_ptid (pid));
+ if (lwp)
+ {
+ /* Leave this status pending for the next time we're able to
+ report it. In the mean time, we'll report this lwp as
+ dead to GDB, so GDB doesn't try to read registers and
+ memory from it. This can only happen if this was the
+ last thread of the process; otherwise, PID is removed
+ from the thread tables before linux_wait_for_event
+ returns. */
+ mark_lwp_dead (lwp, wstat);
+ }
}
if (saved_inferior == NULL || linux_thread_alive (saved_tid))
if (lwp->stopped == 0)
return;
+ /* Cancel actions that rely on GDB not changing the PC (e.g., the
+ user used the "jump" command, or "set $pc = foo"). */
+ if (lwp->stop_pc != get_pc (lwp))
+ {
+ /* Collecting 'while-stepping' actions doesn't make sense
+ anymore. */
+ release_while_stepping_state_list (get_lwp_thread (lwp));
+ }
+
/* 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. */
lwp->pending_signals = p_sig;
}
- if (lwp->status_pending_p && !check_removed_breakpoint (lwp))
- return;
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Not resuming lwp %ld (%s, signal %d, stop %s);"
+ " has pending status\n",
+ lwpid_of (lwp), step ? "step" : "continue", signal,
+ lwp->stop_expected ? "expected" : "not expected");
+ return;
+ }
saved_inferior = current_inferior;
current_inferior = get_lwp_thread (lwp);
if (lwp->bp_reinsert != 0)
{
if (debug_threads)
- fprintf (stderr, " pending reinsert at %08lx", (long)lwp->bp_reinsert);
- if (step == 0)
- fprintf (stderr, "BAD - reinserting but not stepping.\n");
- step = 1;
+ fprintf (stderr, " pending reinsert at 0x%s\n",
+ paddress (lwp->bp_reinsert));
+
+ if (lwp->bp_reinsert != 0 && can_hardware_single_step ())
+ {
+ 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 (lwp);
+ /* If we have while-stepping actions in this thread set it stepping.
+ If we have a signal to deliver, it may or may not be set to
+ SIG_IGN, we don't know. Assume so, and allow collecting
+ while-stepping into a signal handler. A possible smart thing to
+ do would be to set an internal breakpoint at the signal return
+ address, continue, and carry on catching this while-stepping
+ action only when that breakpoint is hit. A future
+ enhancement. */
+ if (get_lwp_thread (lwp)->while_stepping != NULL
+ && can_hardware_single_step ())
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "lwp %ld has a while-stepping action -> forcing step.\n",
+ lwpid_of (lwp));
+ step = 1;
+ }
if (debug_threads && the_low_target.get_pc != NULL)
{
- CORE_ADDR pc = (*the_low_target.get_pc) ();
+ struct regcache *regcache = get_thread_regcache (current_inferior, 1);
+ CORE_ADDR pc = (*the_low_target.get_pc) (regcache);
fprintf (stderr, " resuming from pc 0x%lx\n", (long) pc);
}
get_lwp_thread (lwp));
errno = 0;
lwp->stopped = 0;
+ lwp->stopped_by_watchpoint = 0;
lwp->stepping = step;
- ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0, signal);
+ ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, lwpid_of (lwp), 0,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ of coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG4_TYPE) (uintptr_t) signal);
current_inferior = saved_inferior;
if (errno)
|| (ptid_get_lwp (ptid) == -1
&& (ptid_get_pid (ptid) == pid_of (lwp))))
{
+ if (r->resume[ndx].kind == resume_stop
+ && thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, "already %s LWP %ld at GDB's request\n",
+ thread->last_status.kind == TARGET_WAITKIND_STOPPED
+ ? "stopped"
+ : "stopping",
+ lwpid_of (lwp));
+
+ continue;
+ }
+
lwp->resume = &r->resume[ndx];
+ thread->last_resume_kind = lwp->resume->kind;
+ return 0;
+ }
+ }
+
+ /* No resume action for this thread. */
+ lwp->resume = NULL;
+
+ return 0;
+}
+
+
+/* Set *FLAG_P if this lwp has an interesting status pending. */
+static int
+resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+
+ /* LWPs which will not be resumed are not interesting, because
+ we might not wait for them next time through linux_wait. */
+ if (lwp->resume == NULL)
+ return 0;
+
+ if (lwp->status_pending_p)
+ * (int *) flag_p = 1;
+
+ return 0;
+}
+
+/* Return 1 if this lwp that GDB wants running is stopped at an
+ internal breakpoint that we need to step over. It assumes that any
+ required STOP_PC adjustment has already been propagated to the
+ inferior's regcache. */
+
+static int
+need_step_over_p (struct inferior_list_entry *entry, void *dummy)
+{
+ struct lwp_info *lwp = (struct lwp_info *) entry;
+ struct thread_info *thread;
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
+
+ /* LWPs which will not be resumed are not interesting, because we
+ might not wait for them next time through linux_wait. */
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, not stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, should remain stopped\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ if (!lwp->need_step_over)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? No\n", lwpid_of (lwp));
+ }
+
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Ignoring, has pending status.\n",
+ lwpid_of (lwp));
+ return 0;
+ }
+
+ /* Note: PC, not STOP_PC. Either GDB has adjusted the PC already,
+ or we have. */
+ pc = get_pc (lwp);
+
+ /* If the PC has changed since we stopped, then don't do anything,
+ and let the breakpoint/tracepoint be hit. This happens if, for
+ instance, GDB handled the decr_pc_after_break subtraction itself,
+ GDB is OOL stepping this thread, or the user has issued a "jump"
+ command, or poked thread's registers herself. */
+ if (pc != lwp->stop_pc)
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? Cancelling, PC was changed. "
+ "Old stop_pc was 0x%s, PC is now 0x%s\n",
+ lwpid_of (lwp), paddress (lwp->stop_pc), paddress (pc));
+
+ lwp->need_step_over = 0;
+ return 0;
+ }
+
+ saved_inferior = current_inferior;
+ current_inferior = thread;
+
+ /* We can only step over breakpoints we know about. */
+ if (breakpoint_here (pc))
+ {
+ /* Don't step over a breakpoint that GDB expects to hit
+ though. */
+ if (gdb_breakpoint_here (pc))
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? yes, but found"
+ " GDB breakpoint at 0x%s; skipping step over\n",
+ lwpid_of (lwp), paddress (pc));
+
+ current_inferior = saved_inferior;
return 0;
}
+ else
+ {
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? yes, found breakpoint at 0x%s\n",
+ lwpid_of (lwp), paddress (pc));
+
+ /* We've found an lwp that needs stepping over --- return 1 so
+ that find_inferior stops looking. */
+ current_inferior = saved_inferior;
+
+ /* If the step over is cancelled, this is set again. */
+ lwp->need_step_over = 0;
+ return 1;
+ }
+ }
+
+ current_inferior = saved_inferior;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Need step over [LWP %ld]? No, no breakpoint found at 0x%s\n",
+ lwpid_of (lwp), paddress (pc));
+
+ return 0;
+}
+
+/* Start a step-over operation on LWP. When LWP stopped at a
+ breakpoint, to make progress, we need to remove the breakpoint out
+ of the way. If we let other threads run while we do that, they may
+ pass by the breakpoint location and miss hitting it. To avoid
+ that, a step-over momentarily stops all threads while LWP is
+ single-stepped while the breakpoint is temporarily uninserted from
+ the inferior. When the single-step finishes, we reinsert the
+ breakpoint, and let all threads that are supposed to be running,
+ run again.
+
+ On targets that don't support hardware single-step, we don't
+ currently support full software single-stepping. Instead, we only
+ support stepping over the thread event breakpoint, by asking the
+ low target where to place a reinsert breakpoint. Since this
+ routine assumes the breakpoint being stepped over is a thread event
+ breakpoint, it usually assumes the return address of the current
+ function is a good enough place to set the reinsert breakpoint. */
+
+static int
+start_step_over (struct lwp_info *lwp)
+{
+ struct thread_info *saved_inferior;
+ CORE_ADDR pc;
+ int step;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "Starting step-over on LWP %ld. Stopping all threads\n",
+ lwpid_of (lwp));
+
+ stop_all_lwps ();
+
+ if (debug_threads)
+ fprintf (stderr, "Done stopping all threads for step-over.\n");
+
+ /* Note, we should always reach here with an already adjusted PC,
+ either by GDB (if we're resuming due to GDB's request), or by our
+ caller, if we just finished handling an internal breakpoint GDB
+ shouldn't care about. */
+ pc = get_pc (lwp);
+
+ saved_inferior = current_inferior;
+ current_inferior = get_lwp_thread (lwp);
+
+ lwp->bp_reinsert = pc;
+ uninsert_breakpoints_at (pc);
+
+ if (can_hardware_single_step ())
+ {
+ step = 1;
}
+ else
+ {
+ CORE_ADDR raddr = (*the_low_target.breakpoint_reinsert_addr) ();
+ set_reinsert_breakpoint (raddr);
+ step = 0;
+ }
+
+ current_inferior = saved_inferior;
- /* No resume action for this thread. */
- lwp->resume = NULL;
+ linux_resume_one_lwp (lwp, step, 0, NULL);
- return 0;
+ /* Require next event from this LWP. */
+ step_over_bkpt = lwp->head.id;
+ return 1;
}
+/* Finish a step-over. Reinsert the breakpoint we had uninserted in
+ start_step_over, if still there, and delete any reinsert
+ breakpoints we've set, on non hardware single-step targets. */
-/* Set *FLAG_P if this lwp has an interesting status pending. */
static int
-resume_status_pending_p (struct inferior_list_entry *entry, void *flag_p)
+finish_step_over (struct lwp_info *lwp)
{
- struct lwp_info *lwp = (struct lwp_info *) entry;
+ if (lwp->bp_reinsert != 0)
+ {
+ if (debug_threads)
+ fprintf (stderr, "Finished step over.\n");
- /* LWPs which will not be resumed are not interesting, because
- we might not wait for them next time through linux_wait. */
- if (lwp->resume == NULL)
- return 0;
+ /* Reinsert any breakpoint at LWP->BP_REINSERT. Note that there
+ may be no breakpoint to reinsert there by now. */
+ reinsert_breakpoints_at (lwp->bp_reinsert);
- /* If this thread has a removed breakpoint, we won't have any
- events to report later, so check now. check_removed_breakpoint
- may clear status_pending_p. We avoid calling check_removed_breakpoint
- for any thread that we are not otherwise going to resume - this
- lets us preserve stopped status when two threads hit a breakpoint.
- GDB removes the breakpoint to single-step a particular thread
- past it, then re-inserts it and resumes all threads. We want
- to report the second thread without resuming it in the interim. */
- if (lwp->status_pending_p)
- check_removed_breakpoint (lwp);
+ lwp->bp_reinsert = 0;
- if (lwp->status_pending_p)
- * (int *) flag_p = 1;
+ /* Delete any software-single-step reinsert breakpoints. No
+ longer needed. We don't have to worry about other threads
+ hitting this trap, and later not being able to explain it,
+ because we were stepping over a breakpoint, and we hold all
+ threads but LWP stopped while doing that. */
+ if (!can_hardware_single_step ())
+ delete_reinsert_breakpoints ();
- return 0;
+ step_over_bkpt = null_ptid;
+ return 1;
+ }
+ else
+ return 0;
}
/* This function is called once per thread. We check the thread's resume
struct lwp_info *lwp;
struct thread_info *thread;
int step;
- int pending_flag = * (int *) arg;
+ int leave_all_stopped = * (int *) arg;
+ int leave_pending;
thread = (struct thread_info *) entry;
lwp = get_thread_lwp (thread);
if (lwp->resume->kind == resume_stop)
{
if (debug_threads)
- fprintf (stderr, "suspending LWP %ld\n", lwpid_of (lwp));
+ fprintf (stderr, "resume_stop request for LWP %ld\n", lwpid_of (lwp));
if (!lwp->stopped)
{
if (debug_threads)
- fprintf (stderr, "running -> suspending LWP %ld\n", lwpid_of (lwp));
+ fprintf (stderr, "stopping LWP %ld\n", lwpid_of (lwp));
- lwp->suspended = 1;
+ /* Stop the thread, and wait for the event asynchronously,
+ through the event loop. */
send_sigstop (&lwp->head);
}
else
{
if (debug_threads)
- {
- if (lwp->suspended)
- fprintf (stderr, "already stopped/suspended LWP %ld\n",
- lwpid_of (lwp));
- else
- fprintf (stderr, "already stopped/not suspended LWP %ld\n",
- lwpid_of (lwp));
- }
-
- /* Make sure we leave the LWP suspended, so we don't try to
- resume it without GDB telling us to. FIXME: The LWP may
- have been stopped in an internal event that was not meant
- to be notified back to GDB (e.g., gdbserver breakpoint),
- so we should be reporting a stop event in that case
- too. */
- lwp->suspended = 1;
+ fprintf (stderr, "already stopped LWP %ld\n",
+ lwpid_of (lwp));
+
+ /* The LWP may have been stopped in an internal event that
+ was not meant to be notified back to GDB (e.g., gdbserver
+ breakpoint), so we should be reporting a stop event in
+ this case too. */
+
+ /* If the thread already has a pending SIGSTOP, this is a
+ no-op. Otherwise, something later will presumably resume
+ the thread and this will cause it to cancel any pending
+ operation, due to last_resume_kind == resume_stop. If
+ the thread already has a pending status to report, we
+ will still report it the next time we wait - see
+ status_pending_p_callback. */
+ send_sigstop (&lwp->head);
}
/* For stop requests, we're done. */
lwp->resume = NULL;
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
return 0;
}
- else
- lwp->suspended = 0;
/* If this thread which is about to be resumed has a pending status,
then don't resume any threads - we can just report the pending
status. Make sure to queue any signals that would otherwise be
sent. In all-stop mode, we do this decision based on if *any*
- thread has a pending status. */
- if (non_stop)
- resume_status_pending_p (&lwp->head, &pending_flag);
+ thread has a pending status. If there's a thread that needs the
+ step-over-breakpoint dance, then don't resume any other thread
+ but that particular one. */
+ leave_pending = (lwp->status_pending_p || leave_all_stopped);
- if (!pending_flag)
+ if (!leave_pending)
{
if (debug_threads)
fprintf (stderr, "resuming LWP %ld\n", lwpid_of (lwp));
- if (ptid_equal (lwp->resume->thread, minus_one_ptid)
- && lwp->stepping
- && lwp->pending_is_breakpoint)
- step = 1;
- else
- step = (lwp->resume->kind == resume_step);
-
+ step = (lwp->resume->kind == resume_step);
linux_resume_one_lwp (lwp, step, lwp->resume->sig, NULL);
}
else
}
}
+ thread->last_status.kind = TARGET_WAITKIND_IGNORE;
lwp->resume = NULL;
return 0;
}
static void
linux_resume (struct thread_resume *resume_info, size_t n)
{
- int pending_flag;
struct thread_resume_array array = { resume_info, n };
+ struct lwp_info *need_step_over = NULL;
+ int any_pending;
+ int leave_all_stopped;
find_inferior (&all_threads, linux_set_resume_request, &array);
- /* If there is a thread which would otherwise be resumed, which
- has a pending status, then don't resume any threads - we can just
- report the pending status. Make sure to queue any signals
- that would otherwise be sent. In non-stop mode, we'll apply this
- logic to each thread individually. */
- pending_flag = 0;
+ /* If there is a thread which would otherwise be resumed, which has
+ a pending status, then don't resume any threads - we can just
+ report the pending status. Make sure to queue any signals that
+ would otherwise be sent. In non-stop mode, we'll apply this
+ logic to each thread individually. We consume all pending events
+ before considering to start a step-over (in all-stop). */
+ any_pending = 0;
if (!non_stop)
- find_inferior (&all_lwps, resume_status_pending_p, &pending_flag);
+ find_inferior (&all_lwps, resume_status_pending_p, &any_pending);
+
+ /* If there is a thread which would otherwise be resumed, which is
+ stopped at a breakpoint that needs stepping over, then don't
+ resume any threads - have it step over the breakpoint with all
+ other threads stopped, then resume all threads again. Make sure
+ to queue any signals that would otherwise be delivered or
+ queued. */
+ if (!any_pending && supports_breakpoints ())
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ leave_all_stopped = (need_step_over != NULL || any_pending);
+
+ if (debug_threads)
+ {
+ if (need_step_over != NULL)
+ fprintf (stderr, "Not resuming all, need step over\n");
+ else if (any_pending)
+ fprintf (stderr,
+ "Not resuming, all-stop and found "
+ "an LWP with pending status\n");
+ else
+ fprintf (stderr, "Resuming, no pending status or step over needed\n");
+ }
+
+ /* Even if we're leaving threads stopped, queue all signals we'd
+ otherwise deliver. */
+ find_inferior (&all_threads, linux_resume_one_thread, &leave_all_stopped);
+
+ if (need_step_over)
+ start_step_over (need_step_over);
+}
+
+/* This function is called once per thread. We check the thread's
+ last resume request, which will tell us whether to resume, step, or
+ leave the thread stopped. Any signal the client requested to be
+ delivered has already been enqueued at this point.
+
+ If any thread that GDB wants running is stopped at an internal
+ breakpoint that needs stepping over, we start a step-over operation
+ on that particular thread, and leave all others stopped. */
+
+static void
+proceed_one_lwp (struct inferior_list_entry *entry)
+{
+ struct lwp_info *lwp;
+ struct thread_info *thread;
+ int step;
+
+ lwp = (struct lwp_info *) entry;
+
+ if (debug_threads)
+ fprintf (stderr,
+ "proceed_one_lwp: lwp %ld\n", lwpid_of (lwp));
+
+ if (!lwp->stopped)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld already running\n", lwpid_of (lwp));
+ return;
+ }
+
+ thread = get_lwp_thread (lwp);
+
+ if (thread->last_resume_kind == resume_stop)
+ {
+ if (debug_threads)
+ fprintf (stderr, " client wants LWP %ld stopped\n", lwpid_of (lwp));
+ return;
+ }
+
+ if (lwp->status_pending_p)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld has pending status, leaving stopped\n",
+ lwpid_of (lwp));
+ return;
+ }
+
+ if (lwp->suspended)
+ {
+ if (debug_threads)
+ fprintf (stderr, " LWP %ld is suspended\n", lwpid_of (lwp));
+ return;
+ }
+
+ step = thread->last_resume_kind == resume_step;
+ linux_resume_one_lwp (lwp, step, 0, NULL);
+}
+
+/* When we finish a step-over, set threads running again. If there's
+ another thread that may need a step-over, now's the time to start
+ it. Eventually, we'll move all threads past their breakpoints. */
+
+static void
+proceed_all_lwps (void)
+{
+ struct lwp_info *need_step_over;
+
+ /* If there is a thread which would otherwise be resumed, which is
+ stopped at a breakpoint that needs stepping over, then don't
+ resume any threads - have it step over the breakpoint with all
+ other threads stopped, then resume all threads again. */
+
+ if (supports_breakpoints ())
+ {
+ need_step_over
+ = (struct lwp_info *) find_inferior (&all_lwps,
+ need_step_over_p, NULL);
+
+ if (need_step_over != NULL)
+ {
+ if (debug_threads)
+ fprintf (stderr, "proceed_all_lwps: found "
+ "thread %ld needing a step-over\n",
+ lwpid_of (need_step_over));
+
+ start_step_over (need_step_over);
+ return;
+ }
+ }
+
+ if (debug_threads)
+ fprintf (stderr, "Proceeding, no step-over needed\n");
+
+ for_each_inferior (&all_lwps, proceed_one_lwp);
+}
+
+/* Stopped LWPs that the client wanted to be running, that don't have
+ pending statuses, are set to run again, except for EXCEPT, if not
+ NULL. This undoes a stop_all_lwps call. */
+static void
+unstop_all_lwps (struct lwp_info *except)
+{
if (debug_threads)
{
- if (pending_flag)
- fprintf (stderr, "Not resuming, pending status\n");
+ if (except)
+ fprintf (stderr,
+ "unstopping all lwps, except=(LWP %ld)\n", lwpid_of (except));
else
- fprintf (stderr, "Resuming, no pending status\n");
+ fprintf (stderr,
+ "unstopping all lwps\n");
}
- find_inferior (&all_threads, linux_resume_one_thread, &pending_flag);
+ /* Make sure proceed_one_lwp doesn't try to resume this thread. */
+ if (except != NULL)
+ ++except->suspended;
+
+ for_each_inferior (&all_lwps, proceed_one_lwp);
+
+ if (except != NULL)
+ --except->suspended;
}
#ifdef HAVE_LINUX_USRREGS
/* Fetch one register. */
static void
-fetch_register (int regno)
+fetch_register (struct regcache *regcache, int regno)
{
CORE_ADDR regaddr;
int i, size;
{
errno = 0;
*(PTRACE_XFER_TYPE *) (buf + i) =
- ptrace (PTRACE_PEEKUSER, pid, (PTRACE_ARG3_TYPE) regaddr, 0);
+ ptrace (PTRACE_PEEKUSER, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ of coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) 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;
- }
+ error ("reading register %d: %s", regno, strerror (errno));
}
if (the_low_target.supply_ptrace_register)
- the_low_target.supply_ptrace_register (regno, buf);
+ the_low_target.supply_ptrace_register (regcache, regno, buf);
else
- supply_register (regno, buf);
-
-error_exit:;
+ supply_register (regcache, regno, buf);
}
/* Fetch all registers, or just one, from the child process. */
static void
-usr_fetch_inferior_registers (int regno)
+usr_fetch_inferior_registers (struct regcache *regcache, int regno)
{
if (regno == -1)
for (regno = 0; regno < the_low_target.num_regs; regno++)
- fetch_register (regno);
+ fetch_register (regcache, regno);
else
- fetch_register (regno);
+ fetch_register (regcache, 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)
+usr_store_inferior_registers (struct regcache *regcache, int regno)
{
CORE_ADDR regaddr;
int i, size;
memset (buf, 0, size);
if (the_low_target.collect_ptrace_register)
- the_low_target.collect_ptrace_register (regno, buf);
+ the_low_target.collect_ptrace_register (regcache, regno, buf);
else
- collect_register (regno, buf);
+ collect_register (regcache, regno, buf);
pid = lwpid_of (get_thread_lwp (current_inferior));
for (i = 0; i < size; i += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
- ptrace (PTRACE_POKEUSER, pid, (PTRACE_ARG3_TYPE) regaddr,
- *(PTRACE_XFER_TYPE *) (buf + i));
+ ptrace (PTRACE_POKEUSER, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) regaddr,
+ (PTRACE_ARG4_TYPE) *(PTRACE_XFER_TYPE *) (buf + i));
if (errno != 0)
{
/* At this point, ESRCH should mean the process is
return;
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;
- }
+ error ("writing register %d: %s", regno, strerror (errno));
}
regaddr += sizeof (PTRACE_XFER_TYPE);
}
}
else
for (regno = 0; regno < the_low_target.num_regs; regno++)
- usr_store_inferior_registers (regno);
+ usr_store_inferior_registers (regcache, regno);
}
#endif /* HAVE_LINUX_USRREGS */
#ifdef HAVE_LINUX_REGSETS
static int
-regsets_fetch_inferior_registers ()
+regsets_fetch_inferior_registers (struct regcache *regcache)
{
struct regset_info *regset;
int saw_general_regs = 0;
int pid;
+ struct iovec iov;
regset = target_regsets;
pid = lwpid_of (get_thread_lwp (current_inferior));
while (regset->size >= 0)
{
- void *buf;
- int res;
+ void *buf, *data;
+ int nt_type, res;
if (regset->size == 0 || disabled_regsets[regset - target_regsets])
{
}
buf = xmalloc (regset->size);
+
+ nt_type = regset->nt_type;
+ if (nt_type)
+ {
+ iov.iov_base = buf;
+ iov.iov_len = regset->size;
+ data = (void *) &iov;
+ }
+ else
+ data = buf;
+
#ifndef __sparc__
- res = ptrace (regset->get_request, pid, 0, buf);
+ res = ptrace (regset->get_request, pid, nt_type, data);
#else
- res = ptrace (regset->get_request, pid, buf, 0);
+ res = ptrace (regset->get_request, pid, data, nt_type);
#endif
if (res < 0)
{
}
else if (regset->type == GENERAL_REGS)
saw_general_regs = 1;
- regset->store_function (buf);
+ regset->store_function (regcache, buf);
regset ++;
free (buf);
}
}
static int
-regsets_store_inferior_registers ()
+regsets_store_inferior_registers (struct regcache *regcache)
{
struct regset_info *regset;
int saw_general_regs = 0;
int pid;
+ struct iovec iov;
regset = target_regsets;
pid = lwpid_of (get_thread_lwp (current_inferior));
while (regset->size >= 0)
{
- void *buf;
- int res;
+ void *buf, *data;
+ int nt_type, res;
if (regset->size == 0 || disabled_regsets[regset - target_regsets])
{
/* First fill the buffer with the current register set contents,
in case there are any items in the kernel's regset that are
not in gdbserver's regcache. */
+
+ nt_type = regset->nt_type;
+ if (nt_type)
+ {
+ iov.iov_base = buf;
+ iov.iov_len = regset->size;
+ data = (void *) &iov;
+ }
+ else
+ data = buf;
+
#ifndef __sparc__
- res = ptrace (regset->get_request, pid, 0, buf);
+ res = ptrace (regset->get_request, pid, nt_type, data);
#else
- res = ptrace (regset->get_request, pid, buf, 0);
+ res = ptrace (regset->get_request, pid, &iov, data);
#endif
if (res == 0)
{
/* Then overlay our cached registers on that. */
- regset->fill_function (buf);
+ regset->fill_function (regcache, buf);
/* Only now do we write the register set. */
#ifndef __sparc__
- res = ptrace (regset->set_request, pid, 0, buf);
+ res = ptrace (regset->set_request, pid, nt_type, data);
#else
- res = ptrace (regset->set_request, pid, buf, 0);
+ res = ptrace (regset->set_request, pid, data, nt_type);
#endif
}
void
-linux_fetch_registers (int regno)
+linux_fetch_registers (struct regcache *regcache, int regno)
{
#ifdef HAVE_LINUX_REGSETS
- if (regsets_fetch_inferior_registers () == 0)
+ if (regsets_fetch_inferior_registers (regcache) == 0)
return;
#endif
#ifdef HAVE_LINUX_USRREGS
- usr_fetch_inferior_registers (regno);
+ usr_fetch_inferior_registers (regcache, regno);
#endif
}
void
-linux_store_registers (int regno)
+linux_store_registers (struct regcache *regcache, int regno)
{
#ifdef HAVE_LINUX_REGSETS
- if (regsets_store_inferior_registers () == 0)
+ if (regsets_store_inferior_registers (regcache) == 0)
return;
#endif
#ifdef HAVE_LINUX_USRREGS
- usr_store_inferior_registers (regno);
+ usr_store_inferior_registers (regcache, regno);
#endif
}
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
- buffer[i] = ptrace (PTRACE_PEEKTEXT, pid, (PTRACE_ARG3_TYPE) addr, 0);
+ /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ buffer[i] = ptrace (PTRACE_PEEKTEXT, pid,
+ (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
if (errno)
return errno;
}
return 0;
}
-/* Copy LEN bytes of data from debugger memory at MYADDR
- to inferior's memory at MEMADDR.
- On failure (cannot write the inferior)
+/* Copy LEN bytes of data from debugger memory at MYADDR to inferior's
+ memory at MEMADDR. On failure (cannot write to the inferior)
returns the value of errno. */
static int
/* Fill start and end extra bytes of buffer with existing memory data. */
- buffer[0] = ptrace (PTRACE_PEEKTEXT, pid, (PTRACE_ARG3_TYPE) addr, 0);
+ errno = 0;
+ /* Coerce the 3rd arg to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ buffer[0] = ptrace (PTRACE_PEEKTEXT, pid,
+ (PTRACE_ARG3_TYPE) (uintptr_t) addr, 0);
+ if (errno)
+ return errno;
if (count > 1)
{
+ errno = 0;
buffer[count - 1]
= ptrace (PTRACE_PEEKTEXT, pid,
- (PTRACE_ARG3_TYPE) (addr + (count - 1)
- * sizeof (PTRACE_XFER_TYPE)),
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) (addr + (count - 1)
+ * sizeof (PTRACE_XFER_TYPE)),
0);
+ if (errno)
+ return errno;
}
- /* Copy data to be written over corresponding part of buffer */
+ /* Copy data to be written over corresponding part of buffer. */
memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len);
for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE))
{
errno = 0;
- ptrace (PTRACE_POKETEXT, pid, (PTRACE_ARG3_TYPE) addr, buffer[i]);
+ ptrace (PTRACE_POKETEXT, pid,
+ /* Coerce to a uintptr_t first to avoid potential gcc warning
+ about coercing an 8 byte integer to a 4 byte pointer. */
+ (PTRACE_ARG3_TYPE) (uintptr_t) addr,
+ (PTRACE_ARG4_TYPE) buffer[i]);
if (errno)
return errno;
}
return 0;
}
+/* Non-zero if the kernel supports PTRACE_O_TRACEFORK. */
static int linux_supports_tracefork_flag;
/* Helper functions for linux_test_for_tracefork, called via clone (). */
{
ptrace (PTRACE_TRACEME, 0, 0, 0);
kill (getpid (), SIGSTOP);
+
+#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
+
+ if (fork () == 0)
+ linux_tracefork_grandchild (NULL);
+
+#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
#ifdef __ia64__
__clone2 (linux_tracefork_grandchild, arg, STACK_SIZE,
CLONE_VM | SIGCHLD, NULL);
clone (linux_tracefork_grandchild, arg + STACK_SIZE,
CLONE_VM | SIGCHLD, NULL);
#endif
+
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
_exit (0);
}
{
int child_pid, ret, status;
long second_pid;
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
char *stack = xmalloc (STACK_SIZE * 4);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
linux_supports_tracefork_flag = 0;
+#if !(defined(__UCLIBC__) && defined(HAS_NOMMU))
+
+ child_pid = fork ();
+ if (child_pid == 0)
+ linux_tracefork_child (NULL);
+
+#else /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
/* Use CLONE_VM instead of fork, to support uClinux (no MMU). */
#ifdef __ia64__
child_pid = __clone2 (linux_tracefork_child, stack, STACK_SIZE,
CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
-#else
+#else /* !__ia64__ */
child_pid = clone (linux_tracefork_child, stack + STACK_SIZE,
CLONE_VM | SIGCHLD, stack + STACK_SIZE * 2);
-#endif
+#endif /* !__ia64__ */
+
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
+
if (child_pid == -1)
perror_with_name ("clone");
if (! WIFSTOPPED (status))
error ("linux_test_for_tracefork: waitpid: unexpected status %d.", status);
- ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK);
+ ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0,
+ (PTRACE_ARG4_TYPE) PTRACE_O_TRACEFORK);
if (ret != 0)
{
ret = ptrace (PTRACE_KILL, child_pid, 0, 0);
}
while (WIFSTOPPED (status));
+#if defined(__UCLIBC__) && defined(HAS_NOMMU)
free (stack);
+#endif /* defined(__UCLIBC__) && defined(HAS_NOMMU) */
}
if (proc->private->thread_db != NULL)
return;
+ /* If the kernel supports tracing forks then it also supports tracing
+ clones, and then we don't need to use the magic thread event breakpoint
+ to learn about threads. */
thread_db_init (!linux_supports_tracefork_flag);
#endif
}
static int
linux_stopped_by_watchpoint (void)
{
- if (the_low_target.stopped_by_watchpoint != NULL)
- return the_low_target.stopped_by_watchpoint ();
- else
- return 0;
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+
+ return lwp->stopped_by_watchpoint;
}
static CORE_ADDR
linux_stopped_data_address (void)
{
- if (the_low_target.stopped_data_address != NULL)
- return the_low_target.stopped_data_address ();
- else
- return 0;
+ struct lwp_info *lwp = get_thread_lwp (current_inferior);
+
+ return lwp->stopped_data_address;
}
#if defined(__UCLIBC__) && defined(HAS_NOMMU)
}
#endif
+static int
+compare_ints (const void *xa, const void *xb)
+{
+ int a = *(const int *)xa;
+ int b = *(const int *)xb;
+
+ return a - b;
+}
+
+static int *
+unique (int *b, int *e)
+{
+ int *d = b;
+ while (++b != e)
+ if (*d != *b)
+ *++d = *b;
+ return ++d;
+}
+
+/* Given PID, iterates over all threads in that process.
+
+ Information about each thread, in a format suitable for qXfer:osdata:thread
+ is printed to BUFFER, if it's not NULL. BUFFER is assumed to be already
+ initialized, and the caller is responsible for finishing and appending '\0'
+ to it.
+
+ The list of cores that threads are running on is assigned to *CORES, if it
+ is not NULL. If no cores are found, *CORES will be set to NULL. Caller
+ should free *CORES. */
+
+static void
+list_threads (int pid, struct buffer *buffer, char **cores)
+{
+ int count = 0;
+ int allocated = 10;
+ int *core_numbers = xmalloc (sizeof (int) * allocated);
+ char pathname[128];
+ DIR *dir;
+ struct dirent *dp;
+ struct stat statbuf;
+
+ sprintf (pathname, "/proc/%d/task", pid);
+ if (stat (pathname, &statbuf) == 0 && S_ISDIR (statbuf.st_mode))
+ {
+ dir = opendir (pathname);
+ if (!dir)
+ {
+ free (core_numbers);
+ return;
+ }
+
+ while ((dp = readdir (dir)) != NULL)
+ {
+ unsigned long lwp = strtoul (dp->d_name, NULL, 10);
+
+ if (lwp != 0)
+ {
+ unsigned core = linux_core_of_thread (ptid_build (pid, lwp, 0));
+
+ if (core != -1)
+ {
+ char s[sizeof ("4294967295")];
+ sprintf (s, "%u", core);
+
+ if (count == allocated)
+ {
+ allocated *= 2;
+ core_numbers = realloc (core_numbers,
+ sizeof (int) * allocated);
+ }
+ core_numbers[count++] = core;
+ if (buffer)
+ buffer_xml_printf (buffer,
+ "<item>"
+ "<column name=\"pid\">%d</column>"
+ "<column name=\"tid\">%s</column>"
+ "<column name=\"core\">%s</column>"
+ "</item>", pid, dp->d_name, s);
+ }
+ else
+ {
+ if (buffer)
+ buffer_xml_printf (buffer,
+ "<item>"
+ "<column name=\"pid\">%d</column>"
+ "<column name=\"tid\">%s</column>"
+ "</item>", pid, dp->d_name);
+ }
+ }
+ }
+ }
+
+ if (cores)
+ {
+ *cores = NULL;
+ if (count > 0)
+ {
+ struct buffer buffer2;
+ int *b;
+ int *e;
+ qsort (core_numbers, count, sizeof (int), compare_ints);
+
+ /* Remove duplicates. */
+ b = core_numbers;
+ e = unique (b, core_numbers + count);
+
+ buffer_init (&buffer2);
+
+ for (b = core_numbers; b != e; ++b)
+ {
+ char number[sizeof ("4294967295")];
+ sprintf (number, "%u", *b);
+ buffer_xml_printf (&buffer2, "%s%s",
+ (b == core_numbers) ? "" : ",", number);
+ }
+ buffer_grow_str0 (&buffer2, "");
+
+ *cores = buffer_finish (&buffer2);
+ }
+ }
+ free (core_numbers);
+}
+
+static void
+show_process (int pid, const char *username, struct buffer *buffer)
+{
+ char pathname[128];
+ FILE *f;
+ char cmd[MAXPATHLEN + 1];
+
+ sprintf (pathname, "/proc/%d/cmdline", pid);
+
+ if ((f = fopen (pathname, "r")) != NULL)
+ {
+ size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
+ if (len > 0)
+ {
+ char *cores = 0;
+ int i;
+ for (i = 0; i < len; i++)
+ if (cmd[i] == '\0')
+ cmd[i] = ' ';
+ cmd[len] = '\0';
+
+ buffer_xml_printf (buffer,
+ "<item>"
+ "<column name=\"pid\">%d</column>"
+ "<column name=\"user\">%s</column>"
+ "<column name=\"command\">%s</column>",
+ pid,
+ username,
+ cmd);
+
+ /* This only collects core numbers, and does not print threads. */
+ list_threads (pid, NULL, &cores);
+
+ if (cores)
+ {
+ buffer_xml_printf (buffer,
+ "<column name=\"cores\">%s</column>", cores);
+ free (cores);
+ }
+
+ buffer_xml_printf (buffer, "</item>");
+ }
+ fclose (f);
+ }
+}
+
static int
linux_qxfer_osdata (const char *annex,
unsigned char *readbuf, unsigned const char *writebuf,
static const char *buf;
static long len_avail = -1;
static struct buffer buffer;
+ int processes = 0;
+ int threads = 0;
DIR *dirp;
- if (strcmp (annex, "processes") != 0)
+ if (strcmp (annex, "processes") == 0)
+ processes = 1;
+ else if (strcmp (annex, "threads") == 0)
+ threads = 1;
+ else
return 0;
if (!readbuf || writebuf)
len_avail = 0;
buf = NULL;
buffer_init (&buffer);
- buffer_grow_str (&buffer, "<osdata type=\"processes\">");
+ if (processes)
+ buffer_grow_str (&buffer, "<osdata type=\"processes\">");
+ else if (threads)
+ buffer_grow_str (&buffer, "<osdata type=\"threads\">");
dirp = opendir ("/proc");
if (dirp)
if (stat (procentry, &statbuf) == 0
&& S_ISDIR (statbuf.st_mode))
{
- char pathname[128];
- FILE *f;
- char cmd[MAXPATHLEN + 1];
- struct passwd *entry;
+ int pid = (int) strtoul (dp->d_name, NULL, 10);
- sprintf (pathname, "/proc/%s/cmdline", dp->d_name);
- entry = getpwuid (statbuf.st_uid);
-
- if ((f = fopen (pathname, "r")) != NULL)
+ if (processes)
+ {
+ struct passwd *entry = getpwuid (statbuf.st_uid);
+ show_process (pid, entry ? entry->pw_name : "?", &buffer);
+ }
+ else if (threads)
{
- size_t len = fread (cmd, 1, sizeof (cmd) - 1, f);
- if (len > 0)
- {
- int i;
- for (i = 0; i < len; i++)
- if (cmd[i] == '\0')
- cmd[i] = ' ';
- cmd[len] = '\0';
-
- buffer_xml_printf (
- &buffer,
- "<item>"
- "<column name=\"pid\">%s</column>"
- "<column name=\"user\">%s</column>"
- "<column name=\"command\">%s</column>"
- "</item>",
- dp->d_name,
- entry ? entry->pw_name : "?",
- cmd);
- }
- fclose (f);
+ list_threads (pid, &buffer, NULL);
}
}
}
{
int previous = (linux_event_pipe[0] != -1);
+ if (debug_threads)
+ fprintf (stderr, "linux_async (%d), previous=%d\n",
+ enable, previous);
+
if (previous != enable)
{
sigset_t mask;
return ret;
}
+static int
+linux_core_of_thread (ptid_t ptid)
+{
+ char filename[sizeof ("/proc//task//stat")
+ + 2 * 20 /* decimal digits for 2 numbers, max 2^64 bit each */
+ + 1];
+ FILE *f;
+ char *content = NULL;
+ char *p;
+ char *ts = 0;
+ int content_read = 0;
+ int i;
+ int core;
+
+ sprintf (filename, "/proc/%d/task/%ld/stat",
+ ptid_get_pid (ptid), ptid_get_lwp (ptid));
+ f = fopen (filename, "r");
+ if (!f)
+ return -1;
+
+ for (;;)
+ {
+ int n;
+ content = realloc (content, content_read + 1024);
+ n = fread (content + content_read, 1, 1024, f);
+ content_read += n;
+ if (n < 1024)
+ {
+ content[content_read] = '\0';
+ break;
+ }
+ }
+
+ p = strchr (content, '(');
+ p = strchr (p, ')') + 2; /* skip ")" and a whitespace. */
+
+ p = strtok_r (p, " ", &ts);
+ for (i = 0; i != 36; ++i)
+ p = strtok_r (NULL, " ", &ts);
+
+ if (sscanf (p, "%d", &core) == 0)
+ core = -1;
+
+ free (content);
+ fclose (f);
+
+ return core;
+}
+
+static void
+linux_process_qsupported (const char *query)
+{
+ if (the_low_target.process_qsupported != NULL)
+ the_low_target.process_qsupported (query);
+}
+
+static int
+linux_supports_tracepoints (void)
+{
+ if (*the_low_target.supports_tracepoints == NULL)
+ return 0;
+
+ return (*the_low_target.supports_tracepoints) ();
+}
+
+static CORE_ADDR
+linux_read_pc (struct regcache *regcache)
+{
+ if (the_low_target.get_pc == NULL)
+ return 0;
+
+ return (*the_low_target.get_pc) (regcache);
+}
+
+static void
+linux_write_pc (struct regcache *regcache, CORE_ADDR pc)
+{
+ gdb_assert (the_low_target.set_pc != NULL);
+
+ (*the_low_target.set_pc) (regcache, pc);
+}
+
+static int
+linux_thread_stopped (struct thread_info *thread)
+{
+ return get_thread_lwp (thread)->stopped;
+}
+
+/* This exposes stop-all-threads functionality to other modules. */
+
+static void
+linux_pause_all (void)
+{
+ stop_all_lwps ();
+}
+
static struct target_ops linux_target_ops = {
linux_create_inferior,
linux_attach,
linux_kill,
linux_detach,
+ linux_mourn,
linux_join,
linux_thread_alive,
linux_resume,
linux_start_non_stop,
linux_supports_multi_process,
#ifdef USE_THREAD_DB
- thread_db_handle_monitor_command
+ thread_db_handle_monitor_command,
#else
- NULL
+ NULL,
#endif
+ linux_core_of_thread,
+ linux_process_qsupported,
+ linux_supports_tracepoints,
+ linux_read_pc,
+ linux_write_pc,
+ linux_thread_stopped,
+ linux_pause_all
};
static void
{
/* FIXME drow/2002-06-09: As above, we should check with LinuxThreads
to find what the cancel signal actually is. */
+#ifdef __SIGRTMIN /* Bionic doesn't use SIGRTMIN the way glibc does. */
signal (__SIGRTMIN+1, SIG_IGN);
+#endif
}
void
projects / deliverable / binutils-gdb.git / blobdiff