| /* GNU/Linux native-dependent code common to multiple platforms. |
| |
| Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007 |
| Free Software Foundation, Inc. |
| |
| This file is part of GDB. |
| |
| This program is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2 of the License, or |
| (at your option) any later version. |
| |
| This program is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| GNU General Public License for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with this program; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin Street, Fifth Floor, |
| Boston, MA 02110-1301, USA. */ |
| |
| #include "defs.h" |
| #include "inferior.h" |
| #include "target.h" |
| #include "gdb_string.h" |
| #include "gdb_wait.h" |
| #include "gdb_assert.h" |
| #ifdef HAVE_TKILL_SYSCALL |
| #include <unistd.h> |
| #include <sys/syscall.h> |
| #endif |
| #include <sys/ptrace.h> |
| #include "linux-nat.h" |
| #include "linux-fork.h" |
| #include "gdbthread.h" |
| #include "gdbcmd.h" |
| #include "regcache.h" |
| #include "regset.h" |
| #include "inf-ptrace.h" |
| #include "auxv.h" |
| #include <sys/param.h> /* for MAXPATHLEN */ |
| #include <sys/procfs.h> /* for elf_gregset etc. */ |
| #include "elf-bfd.h" /* for elfcore_write_* */ |
| #include "gregset.h" /* for gregset */ |
| #include "gdbcore.h" /* for get_exec_file */ |
| #include <ctype.h> /* for isdigit */ |
| #include "gdbthread.h" /* for struct thread_info etc. */ |
| #include "gdb_stat.h" /* for struct stat */ |
| #include <fcntl.h> /* for O_RDONLY */ |
| |
| #ifndef O_LARGEFILE |
| #define O_LARGEFILE 0 |
| #endif |
| |
| /* If the system headers did not provide the constants, hard-code the normal |
| values. */ |
| #ifndef PTRACE_EVENT_FORK |
| |
| #define PTRACE_SETOPTIONS 0x4200 |
| #define PTRACE_GETEVENTMSG 0x4201 |
| |
| /* options set using PTRACE_SETOPTIONS */ |
| #define PTRACE_O_TRACESYSGOOD 0x00000001 |
| #define PTRACE_O_TRACEFORK 0x00000002 |
| #define PTRACE_O_TRACEVFORK 0x00000004 |
| #define PTRACE_O_TRACECLONE 0x00000008 |
| #define PTRACE_O_TRACEEXEC 0x00000010 |
| #define PTRACE_O_TRACEVFORKDONE 0x00000020 |
| #define PTRACE_O_TRACEEXIT 0x00000040 |
| |
| /* Wait extended result codes for the above trace options. */ |
| #define PTRACE_EVENT_FORK 1 |
| #define PTRACE_EVENT_VFORK 2 |
| #define PTRACE_EVENT_CLONE 3 |
| #define PTRACE_EVENT_EXEC 4 |
| #define PTRACE_EVENT_VFORK_DONE 5 |
| #define PTRACE_EVENT_EXIT 6 |
| |
| #endif /* PTRACE_EVENT_FORK */ |
| |
| /* We can't always assume that this flag is available, but all systems |
| with the ptrace event handlers also have __WALL, so it's safe to use |
| here. */ |
| #ifndef __WALL |
| #define __WALL 0x40000000 /* Wait for any child. */ |
| #endif |
| |
| /* The single-threaded native GNU/Linux target_ops. We save a pointer for |
| the use of the multi-threaded target. */ |
| static struct target_ops *linux_ops; |
| static struct target_ops linux_ops_saved; |
| |
| /* The saved to_xfer_partial method, inherited from inf-ptrace.c. |
| Called by our to_xfer_partial. */ |
| static LONGEST (*super_xfer_partial) (struct target_ops *, |
| enum target_object, |
| const char *, gdb_byte *, |
| const gdb_byte *, |
| ULONGEST, LONGEST); |
| |
| static int debug_linux_nat; |
| static void |
| show_debug_linux_nat (struct ui_file *file, int from_tty, |
| struct cmd_list_element *c, const char *value) |
| { |
| fprintf_filtered (file, _("Debugging of GNU/Linux lwp module is %s.\n"), |
| value); |
| } |
| |
| static int linux_parent_pid; |
| |
| struct simple_pid_list |
| { |
| int pid; |
| int status; |
| struct simple_pid_list *next; |
| }; |
| struct simple_pid_list *stopped_pids; |
| |
| /* This variable is a tri-state flag: -1 for unknown, 0 if PTRACE_O_TRACEFORK |
| can not be used, 1 if it can. */ |
| |
| static int linux_supports_tracefork_flag = -1; |
| |
| /* If we have PTRACE_O_TRACEFORK, this flag indicates whether we also have |
| PTRACE_O_TRACEVFORKDONE. */ |
| |
| static int linux_supports_tracevforkdone_flag = -1; |
| |
| |
| /* Trivial list manipulation functions to keep track of a list of |
| new stopped processes. */ |
| static void |
| add_to_pid_list (struct simple_pid_list **listp, int pid, int status) |
| { |
| struct simple_pid_list *new_pid = xmalloc (sizeof (struct simple_pid_list)); |
| new_pid->pid = pid; |
| new_pid->status = status; |
| new_pid->next = *listp; |
| *listp = new_pid; |
| } |
| |
| static int |
| pull_pid_from_list (struct simple_pid_list **listp, int pid, int *status) |
| { |
| struct simple_pid_list **p; |
| |
| for (p = listp; *p != NULL; p = &(*p)->next) |
| if ((*p)->pid == pid) |
| { |
| struct simple_pid_list *next = (*p)->next; |
| *status = (*p)->status; |
| xfree (*p); |
| *p = next; |
| return 1; |
| } |
| return 0; |
| } |
| |
| static void |
| linux_record_stopped_pid (int pid, int status) |
| { |
| add_to_pid_list (&stopped_pids, pid, status); |
| } |
| |
| |
| /* A helper function for linux_test_for_tracefork, called after fork (). */ |
| |
| static void |
| linux_tracefork_child (void) |
| { |
| int ret; |
| |
| ptrace (PTRACE_TRACEME, 0, 0, 0); |
| kill (getpid (), SIGSTOP); |
| fork (); |
| _exit (0); |
| } |
| |
| /* Wrapper function for waitpid which handles EINTR. */ |
| |
| static int |
| my_waitpid (int pid, int *status, int flags) |
| { |
| int ret; |
| do |
| { |
| ret = waitpid (pid, status, flags); |
| } |
| while (ret == -1 && errno == EINTR); |
| |
| return ret; |
| } |
| |
| /* Determine if PTRACE_O_TRACEFORK can be used to follow fork events. |
| |
| First, we try to enable fork tracing on ORIGINAL_PID. If this fails, |
| we know that the feature is not available. This may change the tracing |
| options for ORIGINAL_PID, but we'll be setting them shortly anyway. |
| |
| However, if it succeeds, we don't know for sure that the feature is |
| available; old versions of PTRACE_SETOPTIONS ignored unknown options. We |
| create a child process, attach to it, use PTRACE_SETOPTIONS to enable |
| fork tracing, and let it fork. If the process exits, we assume that we |
| can't use TRACEFORK; if we get the fork notification, and we can extract |
| the new child's PID, then we assume that we can. */ |
| |
| static void |
| linux_test_for_tracefork (int original_pid) |
| { |
| int child_pid, ret, status; |
| long second_pid; |
| |
| linux_supports_tracefork_flag = 0; |
| linux_supports_tracevforkdone_flag = 0; |
| |
| ret = ptrace (PTRACE_SETOPTIONS, original_pid, 0, PTRACE_O_TRACEFORK); |
| if (ret != 0) |
| return; |
| |
| child_pid = fork (); |
| if (child_pid == -1) |
| perror_with_name (("fork")); |
| |
| if (child_pid == 0) |
| linux_tracefork_child (); |
| |
| ret = my_waitpid (child_pid, &status, 0); |
| if (ret == -1) |
| perror_with_name (("waitpid")); |
| else if (ret != child_pid) |
| error (_("linux_test_for_tracefork: waitpid: unexpected result %d."), ret); |
| if (! WIFSTOPPED (status)) |
| error (_("linux_test_for_tracefork: waitpid: unexpected status %d."), status); |
| |
| ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, PTRACE_O_TRACEFORK); |
| if (ret != 0) |
| { |
| ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
| if (ret != 0) |
| { |
| warning (_("linux_test_for_tracefork: failed to kill child")); |
| return; |
| } |
| |
| ret = my_waitpid (child_pid, &status, 0); |
| if (ret != child_pid) |
| warning (_("linux_test_for_tracefork: failed to wait for killed child")); |
| else if (!WIFSIGNALED (status)) |
| warning (_("linux_test_for_tracefork: unexpected wait status 0x%x from " |
| "killed child"), status); |
| |
| return; |
| } |
| |
| /* Check whether PTRACE_O_TRACEVFORKDONE is available. */ |
| ret = ptrace (PTRACE_SETOPTIONS, child_pid, 0, |
| PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORKDONE); |
| linux_supports_tracevforkdone_flag = (ret == 0); |
| |
| ret = ptrace (PTRACE_CONT, child_pid, 0, 0); |
| if (ret != 0) |
| warning (_("linux_test_for_tracefork: failed to resume child")); |
| |
| ret = my_waitpid (child_pid, &status, 0); |
| |
| if (ret == child_pid && WIFSTOPPED (status) |
| && status >> 16 == PTRACE_EVENT_FORK) |
| { |
| second_pid = 0; |
| ret = ptrace (PTRACE_GETEVENTMSG, child_pid, 0, &second_pid); |
| if (ret == 0 && second_pid != 0) |
| { |
| int second_status; |
| |
| linux_supports_tracefork_flag = 1; |
| my_waitpid (second_pid, &second_status, 0); |
| ret = ptrace (PTRACE_KILL, second_pid, 0, 0); |
| if (ret != 0) |
| warning (_("linux_test_for_tracefork: failed to kill second child")); |
| my_waitpid (second_pid, &status, 0); |
| } |
| } |
| else |
| warning (_("linux_test_for_tracefork: unexpected result from waitpid " |
| "(%d, status 0x%x)"), ret, status); |
| |
| ret = ptrace (PTRACE_KILL, child_pid, 0, 0); |
| if (ret != 0) |
| warning (_("linux_test_for_tracefork: failed to kill child")); |
| my_waitpid (child_pid, &status, 0); |
| } |
| |
| /* Return non-zero iff we have tracefork functionality available. |
| This function also sets linux_supports_tracefork_flag. */ |
| |
| static int |
| linux_supports_tracefork (int pid) |
| { |
| if (linux_supports_tracefork_flag == -1) |
| linux_test_for_tracefork (pid); |
| return linux_supports_tracefork_flag; |
| } |
| |
| static int |
| linux_supports_tracevforkdone (int pid) |
| { |
| if (linux_supports_tracefork_flag == -1) |
| linux_test_for_tracefork (pid); |
| return linux_supports_tracevforkdone_flag; |
| } |
| |
| |
| void |
| linux_enable_event_reporting (ptid_t ptid) |
| { |
| int pid = ptid_get_lwp (ptid); |
| int options; |
| |
| if (pid == 0) |
| pid = ptid_get_pid (ptid); |
| |
| if (! linux_supports_tracefork (pid)) |
| return; |
| |
| options = PTRACE_O_TRACEFORK | PTRACE_O_TRACEVFORK | PTRACE_O_TRACEEXEC |
| | PTRACE_O_TRACECLONE; |
| if (linux_supports_tracevforkdone (pid)) |
| options |= PTRACE_O_TRACEVFORKDONE; |
| |
| /* Do not enable PTRACE_O_TRACEEXIT until GDB is more prepared to support |
| read-only process state. */ |
| |
| ptrace (PTRACE_SETOPTIONS, pid, 0, options); |
| } |
| |
| static void |
| linux_child_post_attach (int pid) |
| { |
| linux_enable_event_reporting (pid_to_ptid (pid)); |
| check_for_thread_db (); |
| } |
| |
| static void |
| linux_child_post_startup_inferior (ptid_t ptid) |
| { |
| linux_enable_event_reporting (ptid); |
| check_for_thread_db (); |
| } |
| |
| static int |
| linux_child_follow_fork (struct target_ops *ops, int follow_child) |
| { |
| ptid_t last_ptid; |
| struct target_waitstatus last_status; |
| int has_vforked; |
| int parent_pid, child_pid; |
| |
| get_last_target_status (&last_ptid, &last_status); |
| has_vforked = (last_status.kind == TARGET_WAITKIND_VFORKED); |
| parent_pid = ptid_get_lwp (last_ptid); |
| if (parent_pid == 0) |
| parent_pid = ptid_get_pid (last_ptid); |
| child_pid = last_status.value.related_pid; |
| |
| if (! follow_child) |
| { |
| /* We're already attached to the parent, by default. */ |
| |
| /* Before detaching from the child, remove all breakpoints from |
| it. (This won't actually modify the breakpoint list, but will |
| physically remove the breakpoints from the child.) */ |
| /* If we vforked this will remove the breakpoints from the parent |
| also, but they'll be reinserted below. */ |
| detach_breakpoints (child_pid); |
| |
| /* Detach new forked process? */ |
| if (detach_fork) |
| { |
| if (debug_linux_nat) |
| { |
| target_terminal_ours (); |
| fprintf_filtered (gdb_stdlog, |
| "Detaching after fork from child process %d.\n", |
| child_pid); |
| } |
| |
| ptrace (PTRACE_DETACH, child_pid, 0, 0); |
| } |
| else |
| { |
| struct fork_info *fp; |
| /* Retain child fork in ptrace (stopped) state. */ |
| fp = find_fork_pid (child_pid); |
| if (!fp) |
| fp = add_fork (child_pid); |
| fork_save_infrun_state (fp, 0); |
| } |
| |
| if (has_vforked) |
| { |
| gdb_assert (linux_supports_tracefork_flag >= 0); |
| if (linux_supports_tracevforkdone (0)) |
| { |
| int status; |
| |
| ptrace (PTRACE_CONT, parent_pid, 0, 0); |
| my_waitpid (parent_pid, &status, __WALL); |
| if ((status >> 16) != PTRACE_EVENT_VFORK_DONE) |
| warning (_("Unexpected waitpid result %06x when waiting for " |
| "vfork-done"), status); |
| } |
| else |
| { |
| /* We can't insert breakpoints until the child has |
| finished with the shared memory region. We need to |
| wait until that happens. Ideal would be to just |
| call: |
| - ptrace (PTRACE_SYSCALL, parent_pid, 0, 0); |
| - waitpid (parent_pid, &status, __WALL); |
| However, most architectures can't handle a syscall |
| being traced on the way out if it wasn't traced on |
| the way in. |
| |
| We might also think to loop, continuing the child |
| until it exits or gets a SIGTRAP. One problem is |
| that the child might call ptrace with PTRACE_TRACEME. |
| |
| There's no simple and reliable way to figure out when |
| the vforked child will be done with its copy of the |
| shared memory. We could step it out of the syscall, |
| two instructions, let it go, and then single-step the |
| parent once. When we have hardware single-step, this |
| would work; with software single-step it could still |
| be made to work but we'd have to be able to insert |
| single-step breakpoints in the child, and we'd have |
| to insert -just- the single-step breakpoint in the |
| parent. Very awkward. |
| |
| In the end, the best we can do is to make sure it |
| runs for a little while. Hopefully it will be out of |
| range of any breakpoints we reinsert. Usually this |
| is only the single-step breakpoint at vfork's return |
| point. */ |
| |
| usleep (10000); |
| } |
| |
| /* Since we vforked, breakpoints were removed in the parent |
| too. Put them back. */ |
| reattach_breakpoints (parent_pid); |
| } |
| } |
| else |
| { |
| char child_pid_spelling[40]; |
| |
| /* Needed to keep the breakpoint lists in sync. */ |
| if (! has_vforked) |
| detach_breakpoints (child_pid); |
| |
| /* Before detaching from the parent, remove all breakpoints from it. */ |
| remove_breakpoints (); |
| |
| if (debug_linux_nat) |
| { |
| target_terminal_ours (); |
| fprintf_filtered (gdb_stdlog, |
| "Attaching after fork to child process %d.\n", |
| child_pid); |
| } |
| |
| /* If we're vforking, we may want to hold on to the parent until |
| the child exits or execs. At exec time we can remove the old |
| breakpoints from the parent and detach it; at exit time we |
| could do the same (or even, sneakily, resume debugging it - the |
| child's exec has failed, or something similar). |
| |
| This doesn't clean up "properly", because we can't call |
| target_detach, but that's OK; if the current target is "child", |
| then it doesn't need any further cleanups, and lin_lwp will |
| generally not encounter vfork (vfork is defined to fork |
| in libpthread.so). |
| |
| The holding part is very easy if we have VFORKDONE events; |
| but keeping track of both processes is beyond GDB at the |
| moment. So we don't expose the parent to the rest of GDB. |
| Instead we quietly hold onto it until such time as we can |
| safely resume it. */ |
| |
| if (has_vforked) |
| linux_parent_pid = parent_pid; |
| else if (!detach_fork) |
| { |
| struct fork_info *fp; |
| /* Retain parent fork in ptrace (stopped) state. */ |
| fp = find_fork_pid (parent_pid); |
| if (!fp) |
| fp = add_fork (parent_pid); |
| fork_save_infrun_state (fp, 0); |
| } |
| else |
| { |
| target_detach (NULL, 0); |
| } |
| |
| inferior_ptid = pid_to_ptid (child_pid); |
| |
| /* Reinstall ourselves, since we might have been removed in |
| target_detach (which does other necessary cleanup). */ |
| |
| push_target (ops); |
| |
| /* Reset breakpoints in the child as appropriate. */ |
| follow_inferior_reset_breakpoints (); |
| } |
| |
| return 0; |
| } |
| |
| |
| static void |
| linux_child_insert_fork_catchpoint (int pid) |
| { |
| if (! linux_supports_tracefork (pid)) |
| error (_("Your system does not support fork catchpoints.")); |
| } |
| |
| static void |
| linux_child_insert_vfork_catchpoint (int pid) |
| { |
| if (!linux_supports_tracefork (pid)) |
| error (_("Your system does not support vfork catchpoints.")); |
| } |
| |
| static void |
| linux_child_insert_exec_catchpoint (int pid) |
| { |
| if (!linux_supports_tracefork (pid)) |
| error (_("Your system does not support exec catchpoints.")); |
| } |
| |
| /* On GNU/Linux there are no real LWP's. The closest thing to LWP's |
| are processes sharing the same VM space. A multi-threaded process |
| is basically a group of such processes. However, such a grouping |
| is almost entirely a user-space issue; the kernel doesn't enforce |
| such a grouping at all (this might change in the future). In |
| general, we'll rely on the threads library (i.e. the GNU/Linux |
| Threads library) to provide such a grouping. |
| |
| It is perfectly well possible to write a multi-threaded application |
| without the assistance of a threads library, by using the clone |
| system call directly. This module should be able to give some |
| rudimentary support for debugging such applications if developers |
| specify the CLONE_PTRACE flag in the clone system call, and are |
| using the Linux kernel 2.4 or above. |
| |
| Note that there are some peculiarities in GNU/Linux that affect |
| this code: |
| |
| - In general one should specify the __WCLONE flag to waitpid in |
| order to make it report events for any of the cloned processes |
| (and leave it out for the initial process). However, if a cloned |
| process has exited the exit status is only reported if the |
| __WCLONE flag is absent. Linux kernel 2.4 has a __WALL flag, but |
| we cannot use it since GDB must work on older systems too. |
| |
| - When a traced, cloned process exits and is waited for by the |
| debugger, the kernel reassigns it to the original parent and |
| keeps it around as a "zombie". Somehow, the GNU/Linux Threads |
| library doesn't notice this, which leads to the "zombie problem": |
| When debugged a multi-threaded process that spawns a lot of |
| threads will run out of processes, even if the threads exit, |
| because the "zombies" stay around. */ |
| |
| /* List of known LWPs. */ |
| static struct lwp_info *lwp_list; |
| |
| /* Number of LWPs in the list. */ |
| static int num_lwps; |
| |
| |
| #define GET_LWP(ptid) ptid_get_lwp (ptid) |
| #define GET_PID(ptid) ptid_get_pid (ptid) |
| #define is_lwp(ptid) (GET_LWP (ptid) != 0) |
| #define BUILD_LWP(lwp, pid) ptid_build (pid, lwp, 0) |
| |
| /* If the last reported event was a SIGTRAP, this variable is set to |
| the process id of the LWP/thread that got it. */ |
| ptid_t trap_ptid; |
| |
| |
| /* Since we cannot wait (in linux_nat_wait) for the initial process and |
| any cloned processes with a single call to waitpid, we have to use |
| the WNOHANG flag and call waitpid in a loop. To optimize |
| things a bit we use `sigsuspend' to wake us up when a process has |
| something to report (it will send us a SIGCHLD if it has). To make |
| this work we have to juggle with the signal mask. We save the |
| original signal mask such that we can restore it before creating a |
| new process in order to avoid blocking certain signals in the |
| inferior. We then block SIGCHLD during the waitpid/sigsuspend |
| loop. */ |
| |
| /* Original signal mask. */ |
| static sigset_t normal_mask; |
| |
| /* Signal mask for use with sigsuspend in linux_nat_wait, initialized in |
| _initialize_linux_nat. */ |
| static sigset_t suspend_mask; |
| |
| /* Signals to block to make that sigsuspend work. */ |
| static sigset_t blocked_mask; |
| |
| |
| /* Prototypes for local functions. */ |
| static int stop_wait_callback (struct lwp_info *lp, void *data); |
| static int linux_nat_thread_alive (ptid_t ptid); |
| static char *linux_child_pid_to_exec_file (int pid); |
| |
| /* Convert wait status STATUS to a string. Used for printing debug |
| messages only. */ |
| |
| static char * |
| status_to_str (int status) |
| { |
| static char buf[64]; |
| |
| if (WIFSTOPPED (status)) |
| snprintf (buf, sizeof (buf), "%s (stopped)", |
| strsignal (WSTOPSIG (status))); |
| else if (WIFSIGNALED (status)) |
| snprintf (buf, sizeof (buf), "%s (terminated)", |
| strsignal (WSTOPSIG (status))); |
| else |
| snprintf (buf, sizeof (buf), "%d (exited)", WEXITSTATUS (status)); |
| |
| return buf; |
| } |
| |
| /* Initialize the list of LWPs. Note that this module, contrary to |
| what GDB's generic threads layer does for its thread list, |
| re-initializes the LWP lists whenever we mourn or detach (which |
| doesn't involve mourning) the inferior. */ |
| |
| static void |
| init_lwp_list (void) |
| { |
| struct lwp_info *lp, *lpnext; |
| |
| for (lp = lwp_list; lp; lp = lpnext) |
| { |
| lpnext = lp->next; |
| xfree (lp); |
| } |
| |
| lwp_list = NULL; |
| num_lwps = 0; |
| } |
| |
| /* Add the LWP specified by PID to the list. Return a pointer to the |
| structure describing the new LWP. */ |
| |
| static struct lwp_info * |
| add_lwp (ptid_t ptid) |
| { |
| struct lwp_info *lp; |
| |
| gdb_assert (is_lwp (ptid)); |
| |
| lp = (struct lwp_info *) xmalloc (sizeof (struct lwp_info)); |
| |
| memset (lp, 0, sizeof (struct lwp_info)); |
| |
| lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| |
| lp->ptid = ptid; |
| |
| lp->next = lwp_list; |
| lwp_list = lp; |
| ++num_lwps; |
| |
| return lp; |
| } |
| |
| /* Remove the LWP specified by PID from the list. */ |
| |
| static void |
| delete_lwp (ptid_t ptid) |
| { |
| struct lwp_info *lp, *lpprev; |
| |
| lpprev = NULL; |
| |
| for (lp = lwp_list; lp; lpprev = lp, lp = lp->next) |
| if (ptid_equal (lp->ptid, ptid)) |
| break; |
| |
| if (!lp) |
| return; |
| |
| num_lwps--; |
| |
| if (lpprev) |
| lpprev->next = lp->next; |
| else |
| lwp_list = lp->next; |
| |
| xfree (lp); |
| } |
| |
| /* Return a pointer to the structure describing the LWP corresponding |
| to PID. If no corresponding LWP could be found, return NULL. */ |
| |
| static struct lwp_info * |
| find_lwp_pid (ptid_t ptid) |
| { |
| struct lwp_info *lp; |
| int lwp; |
| |
| if (is_lwp (ptid)) |
| lwp = GET_LWP (ptid); |
| else |
| lwp = GET_PID (ptid); |
| |
| for (lp = lwp_list; lp; lp = lp->next) |
| if (lwp == GET_LWP (lp->ptid)) |
| return lp; |
| |
| return NULL; |
| } |
| |
| /* Call CALLBACK with its second argument set to DATA for every LWP in |
| the list. If CALLBACK returns 1 for a particular LWP, return a |
| pointer to the structure describing that LWP immediately. |
| Otherwise return NULL. */ |
| |
| struct lwp_info * |
| iterate_over_lwps (int (*callback) (struct lwp_info *, void *), void *data) |
| { |
| struct lwp_info *lp, *lpnext; |
| |
| for (lp = lwp_list; lp; lp = lpnext) |
| { |
| lpnext = lp->next; |
| if ((*callback) (lp, data)) |
| return lp; |
| } |
| |
| return NULL; |
| } |
| |
| /* Update our internal state when changing from one fork (checkpoint, |
| et cetera) to another indicated by NEW_PTID. We can only switch |
| single-threaded applications, so we only create one new LWP, and |
| the previous list is discarded. */ |
| |
| void |
| linux_nat_switch_fork (ptid_t new_ptid) |
| { |
| struct lwp_info *lp; |
| |
| init_lwp_list (); |
| lp = add_lwp (new_ptid); |
| lp->stopped = 1; |
| } |
| |
| /* Record a PTID for later deletion. */ |
| |
| struct saved_ptids |
| { |
| ptid_t ptid; |
| struct saved_ptids *next; |
| }; |
| static struct saved_ptids *threads_to_delete; |
| |
| static void |
| record_dead_thread (ptid_t ptid) |
| { |
| struct saved_ptids *p = xmalloc (sizeof (struct saved_ptids)); |
| p->ptid = ptid; |
| p->next = threads_to_delete; |
| threads_to_delete = p; |
| } |
| |
| /* Delete any dead threads which are not the current thread. */ |
| |
| static void |
| prune_lwps (void) |
| { |
| struct saved_ptids **p = &threads_to_delete; |
| |
| while (*p) |
| if (! ptid_equal ((*p)->ptid, inferior_ptid)) |
| { |
| struct saved_ptids *tmp = *p; |
| delete_thread (tmp->ptid); |
| *p = tmp->next; |
| xfree (tmp); |
| } |
| else |
| p = &(*p)->next; |
| } |
| |
| /* Callback for iterate_over_threads that finds a thread corresponding |
| to the given LWP. */ |
| |
| static int |
| find_thread_from_lwp (struct thread_info *thr, void *dummy) |
| { |
| ptid_t *ptid_p = dummy; |
| |
| if (GET_LWP (thr->ptid) && GET_LWP (thr->ptid) == GET_LWP (*ptid_p)) |
| return 1; |
| else |
| return 0; |
| } |
| |
| /* Handle the exit of a single thread LP. */ |
| |
| static void |
| exit_lwp (struct lwp_info *lp) |
| { |
| if (in_thread_list (lp->ptid)) |
| { |
| /* Core GDB cannot deal with us deleting the current thread. */ |
| if (!ptid_equal (lp->ptid, inferior_ptid)) |
| delete_thread (lp->ptid); |
| else |
| record_dead_thread (lp->ptid); |
| printf_unfiltered (_("[%s exited]\n"), |
| target_pid_to_str (lp->ptid)); |
| } |
| else |
| { |
| /* Even if LP->PTID is not in the global GDB thread list, the |
| LWP may be - with an additional thread ID. We don't need |
| to print anything in this case; thread_db is in use and |
| already took care of that. But it didn't delete the thread |
| in order to handle zombies correctly. */ |
| |
| struct thread_info *thr; |
| |
| thr = iterate_over_threads (find_thread_from_lwp, &lp->ptid); |
| if (thr) |
| { |
| if (!ptid_equal (thr->ptid, inferior_ptid)) |
| delete_thread (thr->ptid); |
| else |
| record_dead_thread (thr->ptid); |
| } |
| } |
| |
| delete_lwp (lp->ptid); |
| } |
| |
| /* Attach to the LWP specified by PID. If VERBOSE is non-zero, print |
| a message telling the user that a new LWP has been added to the |
| process. Return 0 if successful or -1 if the new LWP could not |
| be attached. */ |
| |
| int |
| lin_lwp_attach_lwp (ptid_t ptid, int verbose) |
| { |
| struct lwp_info *lp; |
| |
| gdb_assert (is_lwp (ptid)); |
| |
| /* Make sure SIGCHLD is blocked. We don't want SIGCHLD events |
| to interrupt either the ptrace() or waitpid() calls below. */ |
| if (!sigismember (&blocked_mask, SIGCHLD)) |
| { |
| sigaddset (&blocked_mask, SIGCHLD); |
| sigprocmask (SIG_BLOCK, &blocked_mask, NULL); |
| } |
| |
| lp = find_lwp_pid (ptid); |
| |
| /* We assume that we're already attached to any LWP that has an id |
| equal to the overall process id, and to any LWP that is already |
| in our list of LWPs. If we're not seeing exit events from threads |
| and we've had PID wraparound since we last tried to stop all threads, |
| this assumption might be wrong; fortunately, this is very unlikely |
| to happen. */ |
| if (GET_LWP (ptid) != GET_PID (ptid) && lp == NULL) |
| { |
| pid_t pid; |
| int status; |
| |
| if (ptrace (PTRACE_ATTACH, GET_LWP (ptid), 0, 0) < 0) |
| { |
| /* If we fail to attach to the thread, issue a warning, |
| but continue. One way this can happen is if thread |
| creation is interrupted; as of Linux 2.6.19, a kernel |
| bug may place threads in the thread list and then fail |
| to create them. */ |
| warning (_("Can't attach %s: %s"), target_pid_to_str (ptid), |
| safe_strerror (errno)); |
| return -1; |
| } |
| |
| if (lp == NULL) |
| lp = add_lwp (ptid); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLAL: PTRACE_ATTACH %s, 0, 0 (OK)\n", |
| target_pid_to_str (ptid)); |
| |
| pid = my_waitpid (GET_LWP (ptid), &status, 0); |
| if (pid == -1 && errno == ECHILD) |
| { |
| /* Try again with __WCLONE to check cloned processes. */ |
| pid = my_waitpid (GET_LWP (ptid), &status, __WCLONE); |
| lp->cloned = 1; |
| } |
| |
| gdb_assert (pid == GET_LWP (ptid) |
| && WIFSTOPPED (status) && WSTOPSIG (status)); |
| |
| target_post_attach (pid); |
| |
| lp->stopped = 1; |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "LLAL: waitpid %s received %s\n", |
| target_pid_to_str (ptid), |
| status_to_str (status)); |
| } |
| } |
| else |
| { |
| /* We assume that the LWP representing the original process is |
| already stopped. Mark it as stopped in the data structure |
| that the GNU/linux ptrace layer uses to keep track of |
| threads. Note that this won't have already been done since |
| the main thread will have, we assume, been stopped by an |
| attach from a different layer. */ |
| if (lp == NULL) |
| lp = add_lwp (ptid); |
| lp->stopped = 1; |
| } |
| |
| if (verbose) |
| printf_filtered (_("[New %s]\n"), target_pid_to_str (ptid)); |
| |
| return 0; |
| } |
| |
| static void |
| linux_nat_attach (char *args, int from_tty) |
| { |
| struct lwp_info *lp; |
| pid_t pid; |
| int status; |
| |
| /* FIXME: We should probably accept a list of process id's, and |
| attach all of them. */ |
| linux_ops->to_attach (args, from_tty); |
| |
| /* Add the initial process as the first LWP to the list. */ |
| inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), GET_PID (inferior_ptid)); |
| lp = add_lwp (inferior_ptid); |
| |
| /* Make sure the initial process is stopped. The user-level threads |
| layer might want to poke around in the inferior, and that won't |
| work if things haven't stabilized yet. */ |
| pid = my_waitpid (GET_PID (inferior_ptid), &status, 0); |
| if (pid == -1 && errno == ECHILD) |
| { |
| warning (_("%s is a cloned process"), target_pid_to_str (inferior_ptid)); |
| |
| /* Try again with __WCLONE to check cloned processes. */ |
| pid = my_waitpid (GET_PID (inferior_ptid), &status, __WCLONE); |
| lp->cloned = 1; |
| } |
| |
| gdb_assert (pid == GET_PID (inferior_ptid) |
| && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP); |
| |
| lp->stopped = 1; |
| |
| /* Fake the SIGSTOP that core GDB expects. */ |
| lp->status = W_STOPCODE (SIGSTOP); |
| lp->resumed = 1; |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "LLA: waitpid %ld, faking SIGSTOP\n", (long) pid); |
| } |
| } |
| |
| static int |
| detach_callback (struct lwp_info *lp, void *data) |
| { |
| gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
| |
| if (debug_linux_nat && lp->status) |
| fprintf_unfiltered (gdb_stdlog, "DC: Pending %s for %s on detach.\n", |
| strsignal (WSTOPSIG (lp->status)), |
| target_pid_to_str (lp->ptid)); |
| |
| while (lp->signalled && lp->stopped) |
| { |
| errno = 0; |
| if (ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, |
| WSTOPSIG (lp->status)) < 0) |
| error (_("Can't continue %s: %s"), target_pid_to_str (lp->ptid), |
| safe_strerror (errno)); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "DC: PTRACE_CONTINUE (%s, 0, %s) (OK)\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str (lp->status)); |
| |
| lp->stopped = 0; |
| lp->signalled = 0; |
| lp->status = 0; |
| /* FIXME drow/2003-08-26: There was a call to stop_wait_callback |
| here. But since lp->signalled was cleared above, |
| stop_wait_callback didn't do anything; the process was left |
| running. Shouldn't we be waiting for it to stop? |
| I've removed the call, since stop_wait_callback now does do |
| something when called with lp->signalled == 0. */ |
| |
| gdb_assert (lp->status == 0 || WIFSTOPPED (lp->status)); |
| } |
| |
| /* We don't actually detach from the LWP that has an id equal to the |
| overall process id just yet. */ |
| if (GET_LWP (lp->ptid) != GET_PID (lp->ptid)) |
| { |
| errno = 0; |
| if (ptrace (PTRACE_DETACH, GET_LWP (lp->ptid), 0, |
| WSTOPSIG (lp->status)) < 0) |
| error (_("Can't detach %s: %s"), target_pid_to_str (lp->ptid), |
| safe_strerror (errno)); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "PTRACE_DETACH (%s, %s, 0) (OK)\n", |
| target_pid_to_str (lp->ptid), |
| strsignal (WSTOPSIG (lp->status))); |
| |
| delete_lwp (lp->ptid); |
| } |
| |
| return 0; |
| } |
| |
| static void |
| linux_nat_detach (char *args, int from_tty) |
| { |
| iterate_over_lwps (detach_callback, NULL); |
| |
| /* Only the initial process should be left right now. */ |
| gdb_assert (num_lwps == 1); |
| |
| trap_ptid = null_ptid; |
| |
| /* Destroy LWP info; it's no longer valid. */ |
| init_lwp_list (); |
| |
| /* Restore the original signal mask. */ |
| sigprocmask (SIG_SETMASK, &normal_mask, NULL); |
| sigemptyset (&blocked_mask); |
| |
| inferior_ptid = pid_to_ptid (GET_PID (inferior_ptid)); |
| linux_ops->to_detach (args, from_tty); |
| } |
| |
| /* Resume LP. */ |
| |
| static int |
| resume_callback (struct lwp_info *lp, void *data) |
| { |
| if (lp->stopped && lp->status == 0) |
| { |
| struct thread_info *tp; |
| |
| linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)), |
| 0, TARGET_SIGNAL_0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "RC: PTRACE_CONT %s, 0, 0 (resume sibling)\n", |
| target_pid_to_str (lp->ptid)); |
| lp->stopped = 0; |
| lp->step = 0; |
| } |
| |
| return 0; |
| } |
| |
| static int |
| resume_clear_callback (struct lwp_info *lp, void *data) |
| { |
| lp->resumed = 0; |
| return 0; |
| } |
| |
| static int |
| resume_set_callback (struct lwp_info *lp, void *data) |
| { |
| lp->resumed = 1; |
| return 0; |
| } |
| |
| static void |
| linux_nat_resume (ptid_t ptid, int step, enum target_signal signo) |
| { |
| struct lwp_info *lp; |
| int resume_all; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: Preparing to %s %s, %s, inferior_ptid %s\n", |
| step ? "step" : "resume", |
| target_pid_to_str (ptid), |
| signo ? strsignal (signo) : "0", |
| target_pid_to_str (inferior_ptid)); |
| |
| prune_lwps (); |
| |
| /* A specific PTID means `step only this process id'. */ |
| resume_all = (PIDGET (ptid) == -1); |
| |
| if (resume_all) |
| iterate_over_lwps (resume_set_callback, NULL); |
| else |
| iterate_over_lwps (resume_clear_callback, NULL); |
| |
| /* If PID is -1, it's the current inferior that should be |
| handled specially. */ |
| if (PIDGET (ptid) == -1) |
| ptid = inferior_ptid; |
| |
| lp = find_lwp_pid (ptid); |
| if (lp) |
| { |
| ptid = pid_to_ptid (GET_LWP (lp->ptid)); |
| |
| /* Remember if we're stepping. */ |
| lp->step = step; |
| |
| /* Mark this LWP as resumed. */ |
| lp->resumed = 1; |
| |
| /* If we have a pending wait status for this thread, there is no |
| point in resuming the process. But first make sure that |
| linux_nat_wait won't preemptively handle the event - we |
| should never take this short-circuit if we are going to |
| leave LP running, since we have skipped resuming all the |
| other threads. This bit of code needs to be synchronized |
| with linux_nat_wait. */ |
| |
| if (lp->status && WIFSTOPPED (lp->status)) |
| { |
| int saved_signo = target_signal_from_host (WSTOPSIG (lp->status)); |
| |
| if (signal_stop_state (saved_signo) == 0 |
| && signal_print_state (saved_signo) == 0 |
| && signal_pass_state (saved_signo) == 1) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: Not short circuiting for ignored " |
| "status 0x%x\n", lp->status); |
| |
| /* FIXME: What should we do if we are supposed to continue |
| this thread with a signal? */ |
| gdb_assert (signo == TARGET_SIGNAL_0); |
| signo = saved_signo; |
| lp->status = 0; |
| } |
| } |
| |
| if (lp->status) |
| { |
| /* FIXME: What should we do if we are supposed to continue |
| this thread with a signal? */ |
| gdb_assert (signo == TARGET_SIGNAL_0); |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: Short circuiting for status 0x%x\n", |
| lp->status); |
| |
| return; |
| } |
| |
| /* Mark LWP as not stopped to prevent it from being continued by |
| resume_callback. */ |
| lp->stopped = 0; |
| } |
| |
| if (resume_all) |
| iterate_over_lwps (resume_callback, NULL); |
| |
| linux_ops->to_resume (ptid, step, signo); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLR: %s %s, %s (resume event thread)\n", |
| step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (ptid), |
| signo ? strsignal (signo) : "0"); |
| } |
| |
| /* Issue kill to specified lwp. */ |
| |
| static int tkill_failed; |
| |
| static int |
| kill_lwp (int lwpid, int signo) |
| { |
| errno = 0; |
| |
| /* 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. */ |
| |
| #ifdef HAVE_TKILL_SYSCALL |
| if (!tkill_failed) |
| { |
| int ret = syscall (__NR_tkill, lwpid, signo); |
| if (errno != ENOSYS) |
| return ret; |
| errno = 0; |
| tkill_failed = 1; |
| } |
| #endif |
| |
| return kill (lwpid, signo); |
| } |
| |
| /* Handle a GNU/Linux extended wait response. If we see a clone |
| event, we need to add the new LWP to our list (and not report the |
| trap to higher layers). This function returns non-zero if the |
| event should be ignored and we should wait again. If STOPPING is |
| true, the new LWP remains stopped, otherwise it is continued. */ |
| |
| static int |
| linux_handle_extended_wait (struct lwp_info *lp, int status, |
| int stopping) |
| { |
| int pid = GET_LWP (lp->ptid); |
| struct target_waitstatus *ourstatus = &lp->waitstatus; |
| struct lwp_info *new_lp = NULL; |
| int event = status >> 16; |
| |
| if (event == PTRACE_EVENT_FORK || event == PTRACE_EVENT_VFORK |
| || event == PTRACE_EVENT_CLONE) |
| { |
| unsigned long new_pid; |
| int ret; |
| |
| ptrace (PTRACE_GETEVENTMSG, pid, 0, &new_pid); |
| |
| /* If we haven't already seen the new PID stop, wait for it now. */ |
| if (! pull_pid_from_list (&stopped_pids, new_pid, &status)) |
| { |
| /* The new child has a pending SIGSTOP. We can't affect it until it |
| hits the SIGSTOP, but we're already attached. */ |
| ret = my_waitpid (new_pid, &status, |
| (event == PTRACE_EVENT_CLONE) ? __WCLONE : 0); |
| if (ret == -1) |
| perror_with_name (_("waiting for new child")); |
| else if (ret != new_pid) |
| internal_error (__FILE__, __LINE__, |
| _("wait returned unexpected PID %d"), ret); |
| else if (!WIFSTOPPED (status)) |
| internal_error (__FILE__, __LINE__, |
| _("wait returned unexpected status 0x%x"), status); |
| } |
| |
| ourstatus->value.related_pid = new_pid; |
| |
| if (event == PTRACE_EVENT_FORK) |
| ourstatus->kind = TARGET_WAITKIND_FORKED; |
| else if (event == PTRACE_EVENT_VFORK) |
| ourstatus->kind = TARGET_WAITKIND_VFORKED; |
| else |
| { |
| ourstatus->kind = TARGET_WAITKIND_IGNORE; |
| new_lp = add_lwp (BUILD_LWP (new_pid, GET_PID (inferior_ptid))); |
| new_lp->cloned = 1; |
| |
| if (WSTOPSIG (status) != SIGSTOP) |
| { |
| /* This can happen if someone starts sending signals to |
| the new thread before it gets a chance to run, which |
| have a lower number than SIGSTOP (e.g. SIGUSR1). |
| This is an unlikely case, and harder to handle for |
| fork / vfork than for clone, so we do not try - but |
| we handle it for clone events here. We'll send |
| the other signal on to the thread below. */ |
| |
| new_lp->signalled = 1; |
| } |
| else |
| status = 0; |
| |
| if (stopping) |
| new_lp->stopped = 1; |
| else |
| { |
| new_lp->resumed = 1; |
| ptrace (PTRACE_CONT, lp->waitstatus.value.related_pid, 0, |
| status ? WSTOPSIG (status) : 0); |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LHEW: Got clone event from LWP %ld, resuming\n", |
| GET_LWP (lp->ptid)); |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| |
| return 1; |
| } |
| |
| return 0; |
| } |
| |
| if (event == PTRACE_EVENT_EXEC) |
| { |
| ourstatus->kind = TARGET_WAITKIND_EXECD; |
| ourstatus->value.execd_pathname |
| = xstrdup (linux_child_pid_to_exec_file (pid)); |
| |
| if (linux_parent_pid) |
| { |
| detach_breakpoints (linux_parent_pid); |
| ptrace (PTRACE_DETACH, linux_parent_pid, 0, 0); |
| |
| linux_parent_pid = 0; |
| } |
| |
| return 0; |
| } |
| |
| internal_error (__FILE__, __LINE__, |
| _("unknown ptrace event %d"), event); |
| } |
| |
| /* Wait for LP to stop. Returns the wait status, or 0 if the LWP has |
| exited. */ |
| |
| static int |
| wait_lwp (struct lwp_info *lp) |
| { |
| pid_t pid; |
| int status; |
| int thread_dead = 0; |
| |
| gdb_assert (!lp->stopped); |
| gdb_assert (lp->status == 0); |
| |
| pid = my_waitpid (GET_LWP (lp->ptid), &status, 0); |
| if (pid == -1 && errno == ECHILD) |
| { |
| pid = my_waitpid (GET_LWP (lp->ptid), &status, __WCLONE); |
| if (pid == -1 && errno == ECHILD) |
| { |
| /* The thread has previously exited. We need to delete it |
| now because, for some vendor 2.4 kernels with NPTL |
| support backported, there won't be an exit event unless |
| it is the main thread. 2.6 kernels will report an exit |
| event for each thread that exits, as expected. */ |
| thread_dead = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "WL: %s vanished.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| |
| if (!thread_dead) |
| { |
| gdb_assert (pid == GET_LWP (lp->ptid)); |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "WL: waitpid %s received %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str (status)); |
| } |
| } |
| |
| /* Check if the thread has exited. */ |
| if (WIFEXITED (status) || WIFSIGNALED (status)) |
| { |
| thread_dead = 1; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "WL: %s exited.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| |
| if (thread_dead) |
| { |
| exit_lwp (lp); |
| return 0; |
| } |
| |
| gdb_assert (WIFSTOPPED (status)); |
| |
| /* Handle GNU/Linux's extended waitstatus for trace events. */ |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "WL: Handling extended status 0x%06x\n", |
| status); |
| if (linux_handle_extended_wait (lp, status, 1)) |
| return wait_lwp (lp); |
| } |
| |
| return status; |
| } |
| |
| /* Send a SIGSTOP to LP. */ |
| |
| static int |
| stop_callback (struct lwp_info *lp, void *data) |
| { |
| if (!lp->stopped && !lp->signalled) |
| { |
| int ret; |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SC: kill %s **<SIGSTOP>**\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| errno = 0; |
| ret = kill_lwp (GET_LWP (lp->ptid), SIGSTOP); |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SC: lwp kill %d %s\n", |
| ret, |
| errno ? safe_strerror (errno) : "ERRNO-OK"); |
| } |
| |
| lp->signalled = 1; |
| gdb_assert (lp->status == 0); |
| } |
| |
| return 0; |
| } |
| |
| /* Wait until LP is stopped. If DATA is non-null it is interpreted as |
| a pointer to a set of signals to be flushed immediately. */ |
| |
| static int |
| stop_wait_callback (struct lwp_info *lp, void *data) |
| { |
| sigset_t *flush_mask = data; |
| |
| if (!lp->stopped) |
| { |
| int status; |
| |
| status = wait_lwp (lp); |
| if (status == 0) |
| return 0; |
| |
| /* Ignore any signals in FLUSH_MASK. */ |
| if (flush_mask && sigismember (flush_mask, WSTOPSIG (status))) |
| { |
| if (!lp->signalled) |
| { |
| lp->stopped = 1; |
| return 0; |
| } |
| |
| errno = 0; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "PTRACE_CONT %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| return stop_wait_callback (lp, flush_mask); |
| } |
| |
| if (WSTOPSIG (status) != SIGSTOP) |
| { |
| if (WSTOPSIG (status) == SIGTRAP) |
| { |
| /* 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 |
| thread will have already tripped on it. */ |
| |
| /* Now resume this LWP and get the SIGSTOP event. */ |
| errno = 0; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "PTRACE_CONT %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: Candidate SIGTRAP event in %s\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| /* Hold the SIGTRAP for handling by linux_nat_wait. */ |
| stop_wait_callback (lp, data); |
| /* If there's another event, throw it back into the queue. */ |
| if (lp->status) |
| { |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: kill %s, %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str ((int) status)); |
| } |
| kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (lp->status)); |
| } |
| /* Save the sigtrap event. */ |
| lp->status = status; |
| return 0; |
| } |
| else |
| { |
| /* The thread was stopped with a signal other than |
| SIGSTOP, and didn't accidentally trip a breakpoint. */ |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: Pending event %s in %s\n", |
| status_to_str ((int) status), |
| target_pid_to_str (lp->ptid)); |
| } |
| /* Now resume this LWP and get the SIGSTOP event. */ |
| errno = 0; |
| ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: PTRACE_CONT %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| /* Hold this event/waitstatus while we check to see if |
| there are any more (we still want to get that SIGSTOP). */ |
| stop_wait_callback (lp, data); |
| /* If the lp->status field is still empty, use it to hold |
| this event. If not, then this event must be returned |
| to the event queue of the LWP. */ |
| if (lp->status == 0) |
| lp->status = status; |
| else |
| { |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "SWC: kill %s, %s\n", |
| target_pid_to_str (lp->ptid), |
| status_to_str ((int) status)); |
| } |
| kill_lwp (GET_LWP (lp->ptid), WSTOPSIG (status)); |
| } |
| return 0; |
| } |
| } |
| else |
| { |
| /* We caught the SIGSTOP that we intended to catch, so |
| there's no SIGSTOP pending. */ |
| lp->stopped = 1; |
| lp->signalled = 0; |
| } |
| } |
| |
| return 0; |
| } |
| |
| /* Check whether PID has any pending signals in FLUSH_MASK. If so set |
| the appropriate bits in PENDING, and return 1 - otherwise return 0. */ |
| |
| static int |
| linux_nat_has_pending (int pid, sigset_t *pending, sigset_t *flush_mask) |
| { |
| sigset_t blocked, ignored; |
| int i; |
| |
| linux_proc_pending_signals (pid, pending, &blocked, &ignored); |
| |
| if (!flush_mask) |
| return 0; |
| |
| for (i = 1; i < NSIG; i++) |
| if (sigismember (pending, i)) |
| if (!sigismember (flush_mask, i) |
| || sigismember (&blocked, i) |
| || sigismember (&ignored, i)) |
| sigdelset (pending, i); |
| |
| if (sigisemptyset (pending)) |
| return 0; |
| |
| return 1; |
| } |
| |
| /* DATA is interpreted as a mask of signals to flush. If LP has |
| signals pending, and they are all in the flush mask, then arrange |
| to flush them. LP should be stopped, as should all other threads |
| it might share a signal queue with. */ |
| |
| static int |
| flush_callback (struct lwp_info *lp, void *data) |
| { |
| sigset_t *flush_mask = data; |
| sigset_t pending, intersection, blocked, ignored; |
| int pid, status; |
| |
| /* Normally, when an LWP exits, it is removed from the LWP list. The |
| last LWP isn't removed till later, however. So if there is only |
| one LWP on the list, make sure it's alive. */ |
| if (lwp_list == lp && lp->next == NULL) |
| if (!linux_nat_thread_alive (lp->ptid)) |
| return 0; |
| |
| /* Just because the LWP is stopped doesn't mean that new signals |
| can't arrive from outside, so this function must be careful of |
| race conditions. However, because all threads are stopped, we |
| can assume that the pending mask will not shrink unless we resume |
| the LWP, and that it will then get another signal. We can't |
| control which one, however. */ |
| |
| if (lp->status) |
| { |
| if (debug_linux_nat) |
| printf_unfiltered (_("FC: LP has pending status %06x\n"), lp->status); |
| if (WIFSTOPPED (lp->status) && sigismember (flush_mask, WSTOPSIG (lp->status))) |
| lp->status = 0; |
| } |
| |
| /* While there is a pending signal we would like to flush, continue |
| the inferior and collect another signal. But if there's already |
| a saved status that we don't want to flush, we can't resume the |
| inferior - if it stopped for some other reason we wouldn't have |
| anywhere to save the new status. In that case, we must leave the |
| signal unflushed (and possibly generate an extra SIGINT stop). |
| That's much less bad than losing a signal. */ |
| while (lp->status == 0 |
| && linux_nat_has_pending (GET_LWP (lp->ptid), &pending, flush_mask)) |
| { |
| int ret; |
| |
| errno = 0; |
| ret = ptrace (PTRACE_CONT, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stderr, |
| "FC: Sent PTRACE_CONT, ret %d %d\n", ret, errno); |
| |
| lp->stopped = 0; |
| stop_wait_callback (lp, flush_mask); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stderr, |
| "FC: Wait finished; saved status is %d\n", |
| lp->status); |
| } |
| |
| return 0; |
| } |
| |
| /* Return non-zero if LP has a wait status pending. */ |
| |
| static int |
| status_callback (struct lwp_info *lp, void *data) |
| { |
| /* Only report a pending wait status if we pretend that this has |
| indeed been resumed. */ |
| return (lp->status != 0 && lp->resumed); |
| } |
| |
| /* Return non-zero if LP isn't stopped. */ |
| |
| static int |
| running_callback (struct lwp_info *lp, void *data) |
| { |
| return (lp->stopped == 0 || (lp->status != 0 && lp->resumed)); |
| } |
| |
| /* Count the LWP's that have had events. */ |
| |
| static int |
| count_events_callback (struct lwp_info *lp, void *data) |
| { |
| int *count = data; |
| |
| gdb_assert (count != NULL); |
| |
| /* Count only LWPs that have a SIGTRAP event pending. */ |
| if (lp->status != 0 |
| && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP) |
| (*count)++; |
| |
| return 0; |
| } |
| |
| /* Select the LWP (if any) that is currently being single-stepped. */ |
| |
| static int |
| select_singlestep_lwp_callback (struct lwp_info *lp, void *data) |
| { |
| if (lp->step && lp->status != 0) |
| return 1; |
| else |
| return 0; |
| } |
| |
| /* Select the Nth LWP that has had a SIGTRAP event. */ |
| |
| static int |
| select_event_lwp_callback (struct lwp_info *lp, void *data) |
| { |
| int *selector = data; |
| |
| gdb_assert (selector != NULL); |
| |
| /* Select only LWPs that have a SIGTRAP event pending. */ |
| if (lp->status != 0 |
| && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP) |
| if ((*selector)-- == 0) |
| return 1; |
| |
| return 0; |
| } |
| |
| static int |
| cancel_breakpoints_callback (struct lwp_info *lp, void *data) |
| { |
| 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 (lp->status != 0 |
| && WIFSTOPPED (lp->status) && WSTOPSIG (lp->status) == SIGTRAP |
| && breakpoint_inserted_here_p (read_pc_pid (lp->ptid) - |
| gdbarch_decr_pc_after_break |
| (current_gdbarch))) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "CBC: Push back breakpoint for %s\n", |
| target_pid_to_str (lp->ptid)); |
| |
| /* Back up the PC if necessary. */ |
| if (gdbarch_decr_pc_after_break (current_gdbarch)) |
| write_pc_pid (read_pc_pid (lp->ptid) - gdbarch_decr_pc_after_break |
| (current_gdbarch), |
| lp->ptid); |
| |
| /* Throw away the SIGTRAP. */ |
| lp->status = 0; |
| } |
| |
| return 0; |
| } |
| |
| /* Select one LWP out of those that have events pending. */ |
| |
| static void |
| select_event_lwp (struct lwp_info **orig_lp, int *status) |
| { |
| int num_events = 0; |
| int random_selector; |
| struct lwp_info *event_lp; |
| |
| /* Record the wait status for the original LWP. */ |
| (*orig_lp)->status = *status; |
| |
| /* Give preference to any LWP that is being single-stepped. */ |
| event_lp = iterate_over_lwps (select_singlestep_lwp_callback, NULL); |
| if (event_lp != NULL) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "SEL: Select single-step %s\n", |
| target_pid_to_str (event_lp->ptid)); |
| } |
| 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. */ |
| iterate_over_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_linux_nat && num_events > 1) |
| fprintf_unfiltered (gdb_stdlog, |
| "SEL: Found %d SIGTRAP events, selecting #%d\n", |
| num_events, random_selector); |
| |
| event_lp = iterate_over_lwps (select_event_lwp_callback, |
| &random_selector); |
| } |
| |
| if (event_lp != NULL) |
| { |
| /* Switch the event LWP. */ |
| *orig_lp = event_lp; |
| *status = event_lp->status; |
| } |
| |
| /* Flush the wait status for the event LWP. */ |
| (*orig_lp)->status = 0; |
| } |
| |
| /* Return non-zero if LP has been resumed. */ |
| |
| static int |
| resumed_callback (struct lwp_info *lp, void *data) |
| { |
| return lp->resumed; |
| } |
| |
| /* Stop an active thread, verify it still exists, then resume it. */ |
| |
| static int |
| stop_and_resume_callback (struct lwp_info *lp, void *data) |
| { |
| struct lwp_info *ptr; |
| |
| if (!lp->stopped && !lp->signalled) |
| { |
| stop_callback (lp, NULL); |
| stop_wait_callback (lp, NULL); |
| /* Resume if the lwp still exists. */ |
| for (ptr = lwp_list; ptr; ptr = ptr->next) |
| if (lp == ptr) |
| { |
| resume_callback (lp, NULL); |
| resume_set_callback (lp, NULL); |
| } |
| } |
| return 0; |
| } |
| |
| static ptid_t |
| linux_nat_wait (ptid_t ptid, struct target_waitstatus *ourstatus) |
| { |
| struct lwp_info *lp = NULL; |
| int options = 0; |
| int status = 0; |
| pid_t pid = PIDGET (ptid); |
| sigset_t flush_mask; |
| |
| /* The first time we get here after starting a new inferior, we may |
| not have added it to the LWP list yet - this is the earliest |
| moment at which we know its PID. */ |
| if (num_lwps == 0) |
| { |
| gdb_assert (!is_lwp (inferior_ptid)); |
| |
| inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), |
| GET_PID (inferior_ptid)); |
| lp = add_lwp (inferior_ptid); |
| lp->resumed = 1; |
| } |
| |
| sigemptyset (&flush_mask); |
| |
| /* Make sure SIGCHLD is blocked. */ |
| if (!sigismember (&blocked_mask, SIGCHLD)) |
| { |
| sigaddset (&blocked_mask, SIGCHLD); |
| sigprocmask (SIG_BLOCK, &blocked_mask, NULL); |
| } |
| |
| retry: |
| |
| /* Make sure there is at least one LWP that has been resumed. */ |
| gdb_assert (iterate_over_lwps (resumed_callback, NULL)); |
| |
| /* First check if there is a LWP with a wait status pending. */ |
| if (pid == -1) |
| { |
| /* Any LWP that's been resumed will do. */ |
| lp = iterate_over_lwps (status_callback, NULL); |
| if (lp) |
| { |
| status = lp->status; |
| lp->status = 0; |
| |
| if (debug_linux_nat && status) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Using pending wait status %s for %s.\n", |
| status_to_str (status), |
| target_pid_to_str (lp->ptid)); |
| } |
| |
| /* But if we don't fine one, we'll have to wait, and check both |
| cloned and uncloned processes. We start with the cloned |
| processes. */ |
| options = __WCLONE | WNOHANG; |
| } |
| else if (is_lwp (ptid)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Waiting for specific LWP %s.\n", |
| target_pid_to_str (ptid)); |
| |
| /* We have a specific LWP to check. */ |
| lp = find_lwp_pid (ptid); |
| gdb_assert (lp); |
| status = lp->status; |
| lp->status = 0; |
| |
| if (debug_linux_nat && status) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Using pending wait status %s for %s.\n", |
| status_to_str (status), |
| target_pid_to_str (lp->ptid)); |
| |
| /* If we have to wait, take into account whether PID is a cloned |
| process or not. And we have to convert it to something that |
| the layer beneath us can understand. */ |
| options = lp->cloned ? __WCLONE : 0; |
| pid = GET_LWP (ptid); |
| } |
| |
| if (status && lp->signalled) |
| { |
| /* A pending SIGSTOP may interfere with the normal stream of |
| events. In a typical case where interference is a problem, |
| we have a SIGSTOP signal pending for LWP A while |
| single-stepping it, encounter an event in LWP B, and take the |
| pending SIGSTOP while trying to stop LWP A. After processing |
| the event in LWP B, LWP A is continued, and we'll never see |
| the SIGTRAP associated with the last time we were |
| single-stepping LWP A. */ |
| |
| /* Resume the thread. It should halt immediately returning the |
| pending SIGSTOP. */ |
| registers_changed (); |
| linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, 0, 0 (expect SIGSTOP)\n", |
| lp->step ? "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid)); |
| lp->stopped = 0; |
| gdb_assert (lp->resumed); |
| |
| /* This should catch the pending SIGSTOP. */ |
| stop_wait_callback (lp, NULL); |
| } |
| |
| set_sigint_trap (); /* Causes SIGINT to be passed on to the |
| attached process. */ |
| set_sigio_trap (); |
| |
| while (status == 0) |
| { |
| pid_t lwpid; |
| |
| lwpid = my_waitpid (pid, &status, options); |
| if (lwpid > 0) |
| { |
| gdb_assert (pid == -1 || lwpid == pid); |
| |
| if (debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: waitpid %ld received %s\n", |
| (long) lwpid, status_to_str (status)); |
| } |
| |
| lp = find_lwp_pid (pid_to_ptid (lwpid)); |
| |
| /* Check for stop events reported by a process we didn't |
| already know about - anything not already in our LWP |
| list. |
| |
| If we're expecting to receive stopped processes after |
| fork, vfork, and clone events, then we'll just add the |
| new one to our list and go back to waiting for the event |
| to be reported - the stopped process might be returned |
| from waitpid before or after the event is. */ |
| if (WIFSTOPPED (status) && !lp) |
| { |
| linux_record_stopped_pid (lwpid, status); |
| status = 0; |
| continue; |
| } |
| |
| /* Make sure we don't report an event for the exit of an LWP not in |
| our list, i.e. not part of the current process. This can happen |
| if we detach from a program we original forked and then it |
| exits. */ |
| if (!WIFSTOPPED (status) && !lp) |
| { |
| status = 0; |
| continue; |
| } |
| |
| /* NOTE drow/2003-06-17: This code seems to be meant for debugging |
| CLONE_PTRACE processes which do not use the thread library - |
| otherwise we wouldn't find the new LWP this way. That doesn't |
| currently work, and the following code is currently unreachable |
| due to the two blocks above. If it's fixed some day, this code |
| should be broken out into a function so that we can also pick up |
| LWPs from the new interface. */ |
| if (!lp) |
| { |
| lp = add_lwp (BUILD_LWP (lwpid, GET_PID (inferior_ptid))); |
| if (options & __WCLONE) |
| lp->cloned = 1; |
| |
| gdb_assert (WIFSTOPPED (status) |
| && WSTOPSIG (status) == SIGSTOP); |
| lp->signalled = 1; |
| |
| if (!in_thread_list (inferior_ptid)) |
| { |
| inferior_ptid = BUILD_LWP (GET_PID (inferior_ptid), |
| GET_PID (inferior_ptid)); |
| add_thread (inferior_ptid); |
| } |
| |
| add_thread (lp->ptid); |
| printf_unfiltered (_("[New %s]\n"), |
| target_pid_to_str (lp->ptid)); |
| } |
| |
| /* Handle GNU/Linux's extended waitstatus for trace events. */ |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP && status >> 16 != 0) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Handling extended status 0x%06x\n", |
| status); |
| if (linux_handle_extended_wait (lp, status, 0)) |
| { |
| status = 0; |
| continue; |
| } |
| } |
| |
| /* Check if the thread has exited. */ |
| if ((WIFEXITED (status) || WIFSIGNALED (status)) && num_lwps > 1) |
| { |
| /* If this is the main thread, we must stop all threads and |
| verify if they are still alive. This is because in the nptl |
| thread model, there is no signal issued for exiting LWPs |
| other than the main thread. We only get the main thread |
| exit signal once all child threads have already exited. |
| If we stop all the threads and use the stop_wait_callback |
| to check if they have exited we can determine whether this |
| signal should be ignored or whether it means the end of the |
| debugged application, regardless of which threading model |
| is being used. */ |
| if (GET_PID (lp->ptid) == GET_LWP (lp->ptid)) |
| { |
| lp->stopped = 1; |
| iterate_over_lwps (stop_and_resume_callback, NULL); |
| } |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s exited.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| exit_lwp (lp); |
| |
| /* If there is at least one more LWP, then the exit signal |
| was not the end of the debugged application and should be |
| ignored. */ |
| if (num_lwps > 0) |
| { |
| /* Make sure there is at least one thread running. */ |
| gdb_assert (iterate_over_lwps (running_callback, NULL)); |
| |
| /* Discard the event. */ |
| status = 0; |
| continue; |
| } |
| } |
| |
| /* Check if the current LWP has previously exited. In the nptl |
| thread model, LWPs other than the main thread do not issue |
| signals when they exit so we must check whenever the thread |
| has stopped. A similar check is made in stop_wait_callback(). */ |
| if (num_lwps > 1 && !linux_nat_thread_alive (lp->ptid)) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s exited.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| exit_lwp (lp); |
| |
| /* Make sure there is at least one thread running. */ |
| gdb_assert (iterate_over_lwps (running_callback, NULL)); |
| |
| /* Discard the event. */ |
| status = 0; |
| continue; |
| } |
| |
| /* Make sure we don't report a SIGSTOP that we sent |
| ourselves in an attempt to stop an LWP. */ |
| if (lp->signalled |
| && WIFSTOPPED (status) && WSTOPSIG (status) == SIGSTOP) |
| { |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: Delayed SIGSTOP caught for %s.\n", |
| target_pid_to_str (lp->ptid)); |
| |
| /* This is a delayed SIGSTOP. */ |
| lp->signalled = 0; |
| |
| registers_changed (); |
| linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, TARGET_SIGNAL_0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, 0, 0 (discard SIGSTOP)\n", |
| lp->step ? |
| "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid)); |
| |
| lp->stopped = 0; |
| gdb_assert (lp->resumed); |
| |
| /* Discard the event. */ |
| status = 0; |
| continue; |
| } |
| |
| break; |
| } |
| |
| if (pid == -1) |
| { |
| /* Alternate between checking cloned and uncloned processes. */ |
| options ^= __WCLONE; |
| |
| /* And suspend every time we have checked both. */ |
| if (options & __WCLONE) |
| sigsuspend (&suspend_mask); |
| } |
| |
| /* We shouldn't end up here unless we want to try again. */ |
| gdb_assert (status == 0); |
| } |
| |
| clear_sigio_trap (); |
| clear_sigint_trap (); |
| |
| gdb_assert (lp); |
| |
| /* Don't report signals that GDB isn't interested in, such as |
| signals that are neither printed nor stopped upon. Stopping all |
| threads can be a bit time-consuming so if we want decent |
| performance with heavily multi-threaded programs, especially when |
| they're using a high frequency timer, we'd better avoid it if we |
| can. */ |
| |
| if (WIFSTOPPED (status)) |
| { |
| int signo = target_signal_from_host (WSTOPSIG (status)); |
| |
| /* If we get a signal while single-stepping, we may need special |
| care, e.g. to skip the signal handler. Defer to common code. */ |
| if (!lp->step |
| && signal_stop_state (signo) == 0 |
| && signal_print_state (signo) == 0 |
| && signal_pass_state (signo) == 1) |
| { |
| /* FIMXE: kettenis/2001-06-06: Should we resume all threads |
| here? It is not clear we should. GDB may not expect |
| other threads to run. On the other hand, not resuming |
| newly attached threads may cause an unwanted delay in |
| getting them running. */ |
| registers_changed (); |
| linux_ops->to_resume (pid_to_ptid (GET_LWP (lp->ptid)), |
| lp->step, signo); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: %s %s, %s (preempt 'handle')\n", |
| lp->step ? |
| "PTRACE_SINGLESTEP" : "PTRACE_CONT", |
| target_pid_to_str (lp->ptid), |
| signo ? strsignal (signo) : "0"); |
| lp->stopped = 0; |
| status = 0; |
| goto retry; |
| } |
| |
| if (signo == TARGET_SIGNAL_INT && signal_pass_state (signo) == 0) |
| { |
| /* If ^C/BREAK is typed at the tty/console, SIGINT gets |
| forwarded to the entire process group, that is, all LWP's |
| will receive it. Since we only want to report it once, |
| we try to flush it from all LWPs except this one. */ |
| sigaddset (&flush_mask, SIGINT); |
| } |
| } |
| |
| /* This LWP is stopped now. */ |
| lp->stopped = 1; |
| |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, "LLW: Candidate event %s in %s.\n", |
| status_to_str (status), target_pid_to_str (lp->ptid)); |
| |
| /* Now stop all other LWP's ... */ |
| iterate_over_lwps (stop_callback, NULL); |
| |
| /* ... and wait until all of them have reported back that they're no |
| longer running. */ |
| iterate_over_lwps (stop_wait_callback, &flush_mask); |
| iterate_over_lwps (flush_callback, &flush_mask); |
| |
| /* 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 (pid == -1) |
| select_event_lwp (&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 (cancel_breakpoints_callback, lp); |
| |
| if (WIFSTOPPED (status) && WSTOPSIG (status) == SIGTRAP) |
| { |
| trap_ptid = lp->ptid; |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLW: trap_ptid is %s.\n", |
| target_pid_to_str (trap_ptid)); |
| } |
| else |
| trap_ptid = null_ptid; |
| |
| if (lp->waitstatus.kind != TARGET_WAITKIND_IGNORE) |
| { |
| *ourstatus = lp->waitstatus; |
| lp->waitstatus.kind = TARGET_WAITKIND_IGNORE; |
| } |
| else |
| store_waitstatus (ourstatus, status); |
| |
| return lp->ptid; |
| } |
| |
| static int |
| kill_callback (struct lwp_info *lp, void *data) |
| { |
| errno = 0; |
| ptrace (PTRACE_KILL, GET_LWP (lp->ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "KC: PTRACE_KILL %s, 0, 0 (%s)\n", |
| target_pid_to_str (lp->ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| return 0; |
| } |
| |
| static int |
| kill_wait_callback (struct lwp_info *lp, void *data) |
| { |
| pid_t pid; |
| |
| /* We must make sure that there are no pending events (delayed |
| SIGSTOPs, pending SIGTRAPs, etc.) to make sure the current |
| program doesn't interfere with any following debugging session. */ |
| |
| /* For cloned processes we must check both with __WCLONE and |
| without, since the exit status of a cloned process isn't reported |
| with __WCLONE. */ |
| if (lp->cloned) |
| { |
| do |
| { |
| pid = my_waitpid (GET_LWP (lp->ptid), NULL, __WCLONE); |
| if (pid != (pid_t) -1 && debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "KWC: wait %s received unknown.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| while (pid == GET_LWP (lp->ptid)); |
| |
| gdb_assert (pid == -1 && errno == ECHILD); |
| } |
| |
| do |
| { |
| pid = my_waitpid (GET_LWP (lp->ptid), NULL, 0); |
| if (pid != (pid_t) -1 && debug_linux_nat) |
| { |
| fprintf_unfiltered (gdb_stdlog, |
| "KWC: wait %s received unk.\n", |
| target_pid_to_str (lp->ptid)); |
| } |
| } |
| while (pid == GET_LWP (lp->ptid)); |
| |
| gdb_assert (pid == -1 && errno == ECHILD); |
| return 0; |
| } |
| |
| static void |
| linux_nat_kill (void) |
| { |
| struct target_waitstatus last; |
| ptid_t last_ptid; |
| int status; |
| |
| /* If we're stopped while forking and we haven't followed yet, |
| kill the other task. We need to do this first because the |
| parent will be sleeping if this is a vfork. */ |
| |
| get_last_target_status (&last_ptid, &last); |
| |
| if (last.kind == TARGET_WAITKIND_FORKED |
| || last.kind == TARGET_WAITKIND_VFORKED) |
| { |
| ptrace (PT_KILL, last.value.related_pid, 0, 0); |
| wait (&status); |
| } |
| |
| if (forks_exist_p ()) |
| linux_fork_killall (); |
| else |
| { |
| /* Kill all LWP's ... */ |
| iterate_over_lwps (kill_callback, NULL); |
| |
| /* ... and wait until we've flushed all events. */ |
| iterate_over_lwps (kill_wait_callback, NULL); |
| } |
| |
| target_mourn_inferior (); |
| } |
| |
| static void |
| linux_nat_mourn_inferior (void) |
| { |
| trap_ptid = null_ptid; |
| |
| /* Destroy LWP info; it's no longer valid. */ |
| init_lwp_list (); |
| |
| /* Restore the original signal mask. */ |
| sigprocmask (SIG_SETMASK, &normal_mask, NULL); |
| sigemptyset (&blocked_mask); |
| |
| if (! forks_exist_p ()) |
| /* Normal case, no other forks available. */ |
| linux_ops->to_mourn_inferior (); |
| else |
| /* Multi-fork case. The current inferior_ptid has exited, but |
| there are other viable forks to debug. Delete the exiting |
| one and context-switch to the first available. */ |
| linux_fork_mourn_inferior (); |
| } |
| |
| static LONGEST |
| linux_nat_xfer_partial (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, |
| ULONGEST offset, LONGEST len) |
| { |
| struct cleanup *old_chain = save_inferior_ptid (); |
| LONGEST xfer; |
| |
| if (is_lwp (inferior_ptid)) |
| inferior_ptid = pid_to_ptid (GET_LWP (inferior_ptid)); |
| |
| xfer = linux_ops->to_xfer_partial (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| do_cleanups (old_chain); |
| return xfer; |
| } |
| |
| static int |
| linux_nat_thread_alive (ptid_t ptid) |
| { |
| gdb_assert (is_lwp (ptid)); |
| |
| errno = 0; |
| ptrace (PTRACE_PEEKUSER, GET_LWP (ptid), 0, 0); |
| if (debug_linux_nat) |
| fprintf_unfiltered (gdb_stdlog, |
| "LLTA: PTRACE_PEEKUSER %s, 0, 0 (%s)\n", |
| target_pid_to_str (ptid), |
| errno ? safe_strerror (errno) : "OK"); |
| |
| /* Not every Linux kernel implements PTRACE_PEEKUSER. But we can |
| handle that case gracefully since ptrace will first do a lookup |
| for the process based upon the passed-in pid. If that fails we |
| will get either -ESRCH or -EPERM, otherwise the child exists and |
| is alive. */ |
| if (errno == ESRCH || errno == EPERM) |
| return 0; |
| |
| return 1; |
| } |
| |
| static char * |
| linux_nat_pid_to_str (ptid_t ptid) |
| { |
| static char buf[64]; |
| |
| if (lwp_list && lwp_list->next && is_lwp (ptid)) |
| { |
| snprintf (buf, sizeof (buf), "LWP %ld", GET_LWP (ptid)); |
| return buf; |
| } |
| |
| return normal_pid_to_str (ptid); |
| } |
| |
| static void |
| sigchld_handler (int signo) |
| { |
| /* Do nothing. The only reason for this handler is that it allows |
| us to use sigsuspend in linux_nat_wait above to wait for the |
| arrival of a SIGCHLD. */ |
| } |
| |
| /* Accepts an integer PID; Returns a string representing a file that |
| can be opened to get the symbols for the child process. */ |
| |
| static char * |
| linux_child_pid_to_exec_file (int pid) |
| { |
| char *name1, *name2; |
| |
| name1 = xmalloc (MAXPATHLEN); |
| name2 = xmalloc (MAXPATHLEN); |
| make_cleanup (xfree, name1); |
| make_cleanup (xfree, name2); |
| memset (name2, 0, MAXPATHLEN); |
| |
| sprintf (name1, "/proc/%d/exe", pid); |
| if (readlink (name1, name2, MAXPATHLEN) > 0) |
| return name2; |
| else |
| return name1; |
| } |
| |
| /* Service function for corefiles and info proc. */ |
| |
| static int |
| read_mapping (FILE *mapfile, |
| long long *addr, |
| long long *endaddr, |
| char *permissions, |
| long long *offset, |
| char *device, long long *inode, char *filename) |
| { |
| int ret = fscanf (mapfile, "%llx-%llx %s %llx %s %llx", |
| addr, endaddr, permissions, offset, device, inode); |
| |
| filename[0] = '\0'; |
| if (ret > 0 && ret != EOF) |
| { |
| /* Eat everything up to EOL for the filename. This will prevent |
| weird filenames (such as one with embedded whitespace) from |
| confusing this code. It also makes this code more robust in |
| respect to annotations the kernel may add after the filename. |
| |
| Note the filename is used for informational purposes |
| only. */ |
| ret += fscanf (mapfile, "%[^\n]\n", filename); |
| } |
| |
| return (ret != 0 && ret != EOF); |
| } |
| |
| /* Fills the "to_find_memory_regions" target vector. Lists the memory |
| regions in the inferior for a corefile. */ |
| |
| static int |
| linux_nat_find_memory_regions (int (*func) (CORE_ADDR, |
| unsigned long, |
| int, int, int, void *), void *obfd) |
| { |
| long long pid = PIDGET (inferior_ptid); |
| char mapsfilename[MAXPATHLEN]; |
| FILE *mapsfile; |
| long long addr, endaddr, size, offset, inode; |
| char permissions[8], device[8], filename[MAXPATHLEN]; |
| int read, write, exec; |
| int ret; |
| |
| /* Compose the filename for the /proc memory map, and open it. */ |
| sprintf (mapsfilename, "/proc/%lld/maps", pid); |
| if ((mapsfile = fopen (mapsfilename, "r")) == NULL) |
| error (_("Could not open %s."), mapsfilename); |
| |
| if (info_verbose) |
| fprintf_filtered (gdb_stdout, |
| "Reading memory regions from %s\n", mapsfilename); |
| |
| /* Now iterate until end-of-file. */ |
| while (read_mapping (mapsfile, &addr, &endaddr, &permissions[0], |
| &offset, &device[0], &inode, &filename[0])) |
| { |
| size = endaddr - addr; |
| |
| /* Get the segment's permissions. */ |
| read = (strchr (permissions, 'r') != 0); |
| write = (strchr (permissions, 'w') != 0); |
| exec = (strchr (permissions, 'x') != 0); |
| |
| if (info_verbose) |
| { |
| fprintf_filtered (gdb_stdout, |
| "Save segment, %lld bytes at 0x%s (%c%c%c)", |
| size, paddr_nz (addr), |
| read ? 'r' : ' ', |
| write ? 'w' : ' ', exec ? 'x' : ' '); |
| if (filename[0]) |
| fprintf_filtered (gdb_stdout, " for %s", filename); |
| fprintf_filtered (gdb_stdout, "\n"); |
| } |
| |
| /* Invoke the callback function to create the corefile |
| segment. */ |
| func (addr, size, read, write, exec, obfd); |
| } |
| fclose (mapsfile); |
| return 0; |
| } |
| |
| /* Records the thread's register state for the corefile note |
| section. */ |
| |
| static char * |
| linux_nat_do_thread_registers (bfd *obfd, ptid_t ptid, |
| char *note_data, int *note_size) |
| { |
| gdb_gregset_t gregs; |
| gdb_fpregset_t fpregs; |
| #ifdef FILL_FPXREGSET |
| gdb_fpxregset_t fpxregs; |
| #endif |
| unsigned long lwp = ptid_get_lwp (ptid); |
| struct regcache *regcache = get_thread_regcache (ptid); |
| struct gdbarch *gdbarch = get_regcache_arch (regcache); |
| const struct regset *regset; |
| int core_regset_p; |
| struct cleanup *old_chain; |
| |
| old_chain = save_inferior_ptid (); |
| inferior_ptid = ptid; |
| target_fetch_registers (regcache, -1); |
| do_cleanups (old_chain); |
| |
| core_regset_p = gdbarch_regset_from_core_section_p (gdbarch); |
| if (core_regset_p |
| && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg", |
| sizeof (gregs))) != NULL |
| && regset->collect_regset != NULL) |
| regset->collect_regset (regset, regcache, -1, |
| &gregs, sizeof (gregs)); |
| else |
| fill_gregset (regcache, &gregs, -1); |
| |
| note_data = (char *) elfcore_write_prstatus (obfd, |
| note_data, |
| note_size, |
| lwp, |
| stop_signal, &gregs); |
| |
| if (core_regset_p |
| && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg2", |
| sizeof (fpregs))) != NULL |
| && regset->collect_regset != NULL) |
| regset->collect_regset (regset, regcache, -1, |
| &fpregs, sizeof (fpregs)); |
| else |
| fill_fpregset (regcache, &fpregs, -1); |
| |
| note_data = (char *) elfcore_write_prfpreg (obfd, |
| note_data, |
| note_size, |
| &fpregs, sizeof (fpregs)); |
| |
| #ifdef FILL_FPXREGSET |
| if (core_regset_p |
| && (regset = gdbarch_regset_from_core_section (gdbarch, ".reg-xfp", |
| sizeof (fpxregs))) != NULL |
| && regset->collect_regset != NULL) |
| regset->collect_regset (regset, regcache, -1, |
| &fpxregs, sizeof (fpxregs)); |
| else |
| fill_fpxregset (regcache, &fpxregs, -1); |
| |
| note_data = (char *) elfcore_write_prxfpreg (obfd, |
| note_data, |
| note_size, |
| &fpxregs, sizeof (fpxregs)); |
| #endif |
| return note_data; |
| } |
| |
| struct linux_nat_corefile_thread_data |
| { |
| bfd *obfd; |
| char *note_data; |
| int *note_size; |
| int num_notes; |
| }; |
| |
| /* Called by gdbthread.c once per thread. Records the thread's |
| register state for the corefile note section. */ |
| |
| static int |
| linux_nat_corefile_thread_callback (struct lwp_info *ti, void *data) |
| { |
| struct linux_nat_corefile_thread_data *args = data; |
| |
| args->note_data = linux_nat_do_thread_registers (args->obfd, |
| ti->ptid, |
| args->note_data, |
| args->note_size); |
| args->num_notes++; |
| |
| return 0; |
| } |
| |
| /* Records the register state for the corefile note section. */ |
| |
| static char * |
| linux_nat_do_registers (bfd *obfd, ptid_t ptid, |
| char *note_data, int *note_size) |
| { |
| return linux_nat_do_thread_registers (obfd, |
| ptid_build (ptid_get_pid (inferior_ptid), |
| ptid_get_pid (inferior_ptid), |
| 0), |
| note_data, note_size); |
| } |
| |
| /* Fills the "to_make_corefile_note" target vector. Builds the note |
| section for a corefile, and returns it in a malloc buffer. */ |
| |
| static char * |
| linux_nat_make_corefile_notes (bfd *obfd, int *note_size) |
| { |
| struct linux_nat_corefile_thread_data thread_args; |
| struct cleanup *old_chain; |
| char fname[16] = { '\0' }; |
| char psargs[80] = { '\0' }; |
| char *note_data = NULL; |
| ptid_t current_ptid = inferior_ptid; |
| gdb_byte *auxv; |
| int auxv_len; |
| |
| if (get_exec_file (0)) |
| { |
| strncpy (fname, strrchr (get_exec_file (0), '/') + 1, sizeof (fname)); |
| strncpy (psargs, get_exec_file (0), sizeof (psargs)); |
| if (get_inferior_args ()) |
| { |
| strncat (psargs, " ", sizeof (psargs) - strlen (psargs)); |
| strncat (psargs, get_inferior_args (), |
| sizeof (psargs) - strlen (psargs)); |
| } |
| note_data = (char *) elfcore_write_prpsinfo (obfd, |
| note_data, |
| note_size, fname, psargs); |
| } |
| |
| /* Dump information for threads. */ |
| thread_args.obfd = obfd; |
| thread_args.note_data = note_data; |
| thread_args.note_size = note_size; |
| thread_args.num_notes = 0; |
| iterate_over_lwps (linux_nat_corefile_thread_callback, &thread_args); |
| if (thread_args.num_notes == 0) |
| { |
| /* iterate_over_threads didn't come up with any threads; just |
| use inferior_ptid. */ |
| note_data = linux_nat_do_registers (obfd, inferior_ptid, |
| note_data, note_size); |
| } |
| else |
| { |
| note_data = thread_args.note_data; |
| } |
| |
| auxv_len = target_read_alloc (¤t_target, TARGET_OBJECT_AUXV, |
| NULL, &auxv); |
| if (auxv_len > 0) |
| { |
| note_data = elfcore_write_note (obfd, note_data, note_size, |
| "CORE", NT_AUXV, auxv, auxv_len); |
| xfree (auxv); |
| } |
| |
| make_cleanup (xfree, note_data); |
| return note_data; |
| } |
| |
| /* Implement the "info proc" command. */ |
| |
| static void |
| linux_nat_info_proc_cmd (char *args, int from_tty) |
| { |
| long long pid = PIDGET (inferior_ptid); |
| FILE *procfile; |
| char **argv = NULL; |
| char buffer[MAXPATHLEN]; |
| char fname1[MAXPATHLEN], fname2[MAXPATHLEN]; |
| int cmdline_f = 1; |
| int cwd_f = 1; |
| int exe_f = 1; |
| int mappings_f = 0; |
| int environ_f = 0; |
| int status_f = 0; |
| int stat_f = 0; |
| int all = 0; |
| struct stat dummy; |
| |
| if (args) |
| { |
| /* Break up 'args' into an argv array. */ |
| if ((argv = buildargv (args)) == NULL) |
| nomem (0); |
| else |
| make_cleanup_freeargv (argv); |
| } |
| while (argv != NULL && *argv != NULL) |
| { |
| if (isdigit (argv[0][0])) |
| { |
| pid = strtoul (argv[0], NULL, 10); |
| } |
| else if (strncmp (argv[0], "mappings", strlen (argv[0])) == 0) |
| { |
| mappings_f = 1; |
| } |
| else if (strcmp (argv[0], "status") == 0) |
| { |
| status_f = 1; |
| } |
| else if (strcmp (argv[0], "stat") == 0) |
| { |
| stat_f = 1; |
| } |
| else if (strcmp (argv[0], "cmd") == 0) |
| { |
| cmdline_f = 1; |
| } |
| else if (strncmp (argv[0], "exe", strlen (argv[0])) == 0) |
| { |
| exe_f = 1; |
| } |
| else if (strcmp (argv[0], "cwd") == 0) |
| { |
| cwd_f = 1; |
| } |
| else if (strncmp (argv[0], "all", strlen (argv[0])) == 0) |
| { |
| all = 1; |
| } |
| else |
| { |
| /* [...] (future options here) */ |
| } |
| argv++; |
| } |
| if (pid == 0) |
| error (_("No current process: you must name one.")); |
| |
| sprintf (fname1, "/proc/%lld", pid); |
| if (stat (fname1, &dummy) != 0) |
| error (_("No /proc directory: '%s'"), fname1); |
| |
| printf_filtered (_("process %lld\n"), pid); |
| if (cmdline_f || all) |
| { |
| sprintf (fname1, "/proc/%lld/cmdline", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| fgets (buffer, sizeof (buffer), procfile); |
| printf_filtered ("cmdline = '%s'\n", buffer); |
| fclose (procfile); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| if (cwd_f || all) |
| { |
| sprintf (fname1, "/proc/%lld/cwd", pid); |
| memset (fname2, 0, sizeof (fname2)); |
| if (readlink (fname1, fname2, sizeof (fname2)) > 0) |
| printf_filtered ("cwd = '%s'\n", fname2); |
| else |
| warning (_("unable to read link '%s'"), fname1); |
| } |
| if (exe_f || all) |
| { |
| sprintf (fname1, "/proc/%lld/exe", pid); |
| memset (fname2, 0, sizeof (fname2)); |
| if (readlink (fname1, fname2, sizeof (fname2)) > 0) |
| printf_filtered ("exe = '%s'\n", fname2); |
| else |
| warning (_("unable to read link '%s'"), fname1); |
| } |
| if (mappings_f || all) |
| { |
| sprintf (fname1, "/proc/%lld/maps", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| long long addr, endaddr, size, offset, inode; |
| char permissions[8], device[8], filename[MAXPATHLEN]; |
| |
| printf_filtered (_("Mapped address spaces:\n\n")); |
| if (gdbarch_addr_bit (current_gdbarch) == 32) |
| { |
| printf_filtered ("\t%10s %10s %10s %10s %7s\n", |
| "Start Addr", |
| " End Addr", |
| " Size", " Offset", "objfile"); |
| } |
| else |
| { |
| printf_filtered (" %18s %18s %10s %10s %7s\n", |
| "Start Addr", |
| " End Addr", |
| " Size", " Offset", "objfile"); |
| } |
| |
| while (read_mapping (procfile, &addr, &endaddr, &permissions[0], |
| &offset, &device[0], &inode, &filename[0])) |
| { |
| size = endaddr - addr; |
| |
| /* FIXME: carlton/2003-08-27: Maybe the printf_filtered |
| calls here (and possibly above) should be abstracted |
| out into their own functions? Andrew suggests using |
| a generic local_address_string instead to print out |
| the addresses; that makes sense to me, too. */ |
| |
| if (gdbarch_addr_bit (current_gdbarch) == 32) |
| { |
| printf_filtered ("\t%#10lx %#10lx %#10x %#10x %7s\n", |
| (unsigned long) addr, /* FIXME: pr_addr */ |
| (unsigned long) endaddr, |
| (int) size, |
| (unsigned int) offset, |
| filename[0] ? filename : ""); |
| } |
| else |
| { |
| printf_filtered (" %#18lx %#18lx %#10x %#10x %7s\n", |
| (unsigned long) addr, /* FIXME: pr_addr */ |
| (unsigned long) endaddr, |
| (int) size, |
| (unsigned int) offset, |
| filename[0] ? filename : ""); |
| } |
| } |
| |
| fclose (procfile); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| if (status_f || all) |
| { |
| sprintf (fname1, "/proc/%lld/status", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| while (fgets (buffer, sizeof (buffer), procfile) != NULL) |
| puts_filtered (buffer); |
| fclose (procfile); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| if (stat_f || all) |
| { |
| sprintf (fname1, "/proc/%lld/stat", pid); |
| if ((procfile = fopen (fname1, "r")) != NULL) |
| { |
| int itmp; |
| char ctmp; |
| long ltmp; |
| |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Process: %d\n"), itmp); |
| if (fscanf (procfile, "(%[^)]) ", &buffer[0]) > 0) |
| printf_filtered (_("Exec file: %s\n"), buffer); |
| if (fscanf (procfile, "%c ", &ctmp) > 0) |
| printf_filtered (_("State: %c\n"), ctmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Parent process: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Process group: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("Session id: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("TTY: %d\n"), itmp); |
| if (fscanf (procfile, "%d ", &itmp) > 0) |
| printf_filtered (_("TTY owner process group: %d\n"), itmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Flags: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Minor faults (no memory page): %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Minor faults, children: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Major faults (memory page faults): %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Major faults, children: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("utime: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("stime: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("utime, children: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("stime, children: %ld\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("jiffies remaining in current time slice: %ld\n"), |
| ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("'nice' value: %ld\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("jiffies until next timeout: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("jiffies until next SIGALRM: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("start time (jiffies since system boot): %ld\n"), |
| ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Virtual memory size: %lu\n"), |
| (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Resident set size: %lu\n"), (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("rlim: %lu\n"), (unsigned long) ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Start of text: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("End of text: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) |
| printf_filtered (_("Start of stack: 0x%lx\n"), ltmp); |
| #if 0 /* Don't know how architecture-dependent the rest is... |
| Anyway the signal bitmap info is available from "status". */ |
| if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */ |
| printf_filtered (_("Kernel stack pointer: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */ |
| printf_filtered (_("Kernel instr pointer: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Pending signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Blocked signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Ignored signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%ld ", <mp) > 0) |
| printf_filtered (_("Catched signals bitmap: 0x%lx\n"), ltmp); |
| if (fscanf (procfile, "%lu ", <mp) > 0) /* FIXME arch? */ |
| printf_filtered (_("wchan (system call): 0x%lx\n"), ltmp); |
| #endif |
| fclose (procfile); |
| } |
| else |
| warning (_("unable to open /proc file '%s'"), fname1); |
| } |
| } |
| |
| /* Implement the to_xfer_partial interface for memory reads using the /proc |
| filesystem. Because we can use a single read() call for /proc, this |
| can be much more efficient than banging away at PTRACE_PEEKTEXT, |
| but it doesn't support writes. */ |
| |
| static LONGEST |
| linux_proc_xfer_partial (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, |
| ULONGEST offset, LONGEST len) |
| { |
| LONGEST ret; |
| int fd; |
| char filename[64]; |
| |
| if (object != TARGET_OBJECT_MEMORY || !readbuf) |
| return 0; |
| |
| /* Don't bother for one word. */ |
| if (len < 3 * sizeof (long)) |
| return 0; |
| |
| /* We could keep this file open and cache it - possibly one per |
| thread. That requires some juggling, but is even faster. */ |
| sprintf (filename, "/proc/%d/mem", PIDGET (inferior_ptid)); |
| fd = open (filename, O_RDONLY | O_LARGEFILE); |
| if (fd == -1) |
| return 0; |
| |
| /* If pread64 is available, use it. It's faster if the kernel |
| supports it (only one syscall), and it's 64-bit safe even on |
| 32-bit platforms (for instance, SPARC debugging a SPARC64 |
| application). */ |
| #ifdef HAVE_PREAD64 |
| if (pread64 (fd, readbuf, len, offset) != len) |
| #else |
| if (lseek (fd, offset, SEEK_SET) == -1 || read (fd, readbuf, len) != len) |
| #endif |
| ret = 0; |
| else |
| ret = len; |
| |
| close (fd); |
| return ret; |
| } |
| |
| /* Parse LINE as a signal set and add its set bits to SIGS. */ |
| |
| static void |
| add_line_to_sigset (const char *line, sigset_t *sigs) |
| { |
| int len = strlen (line) - 1; |
| const char *p; |
| int signum; |
| |
| if (line[len] != '\n') |
| error (_("Could not parse signal set: %s"), line); |
| |
| p = line; |
| signum = len * 4; |
| while (len-- > 0) |
| { |
| int digit; |
| |
| if (*p >= '0' && *p <= '9') |
| digit = *p - '0'; |
| else if (*p >= 'a' && *p <= 'f') |
| digit = *p - 'a' + 10; |
| else |
| error (_("Could not parse signal set: %s"), line); |
| |
| signum -= 4; |
| |
| if (digit & 1) |
| sigaddset (sigs, signum + 1); |
| if (digit & 2) |
| sigaddset (sigs, signum + 2); |
| if (digit & 4) |
| sigaddset (sigs, signum + 3); |
| if (digit & 8) |
| sigaddset (sigs, signum + 4); |
| |
| p++; |
| } |
| } |
| |
| /* Find process PID's pending signals from /proc/pid/status and set |
| SIGS to match. */ |
| |
| void |
| linux_proc_pending_signals (int pid, sigset_t *pending, sigset_t *blocked, sigset_t *ignored) |
| { |
| FILE *procfile; |
| char buffer[MAXPATHLEN], fname[MAXPATHLEN]; |
| int signum; |
| |
| sigemptyset (pending); |
| sigemptyset (blocked); |
| sigemptyset (ignored); |
| sprintf (fname, "/proc/%d/status", pid); |
| procfile = fopen (fname, "r"); |
| if (procfile == NULL) |
| error (_("Could not open %s"), fname); |
| |
| while (fgets (buffer, MAXPATHLEN, procfile) != NULL) |
| { |
| /* Normal queued signals are on the SigPnd line in the status |
| file. However, 2.6 kernels also have a "shared" pending |
| queue for delivering signals to a thread group, so check for |
| a ShdPnd line also. |
| |
| Unfortunately some Red Hat kernels include the shared pending |
| queue but not the ShdPnd status field. */ |
| |
| if (strncmp (buffer, "SigPnd:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, pending); |
| else if (strncmp (buffer, "ShdPnd:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, pending); |
| else if (strncmp (buffer, "SigBlk:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, blocked); |
| else if (strncmp (buffer, "SigIgn:\t", 8) == 0) |
| add_line_to_sigset (buffer + 8, ignored); |
| } |
| |
| fclose (procfile); |
| } |
| |
| static LONGEST |
| linux_xfer_partial (struct target_ops *ops, enum target_object object, |
| const char *annex, gdb_byte *readbuf, |
| const gdb_byte *writebuf, ULONGEST offset, LONGEST len) |
| { |
| LONGEST xfer; |
| |
| if (object == TARGET_OBJECT_AUXV) |
| return procfs_xfer_auxv (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| |
| xfer = linux_proc_xfer_partial (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| if (xfer != 0) |
| return xfer; |
| |
| return super_xfer_partial (ops, object, annex, readbuf, writebuf, |
| offset, len); |
| } |
| |
| /* Create a prototype generic Linux target. The client can override |
| it with local methods. */ |
| |
| static void |
| linux_target_install_ops (struct target_ops *t) |
| { |
| t->to_insert_fork_catchpoint = linux_child_insert_fork_catchpoint; |
| t->to_insert_vfork_catchpoint = linux_child_insert_vfork_catchpoint; |
| t->to_insert_exec_catchpoint = linux_child_insert_exec_catchpoint; |
| t->to_pid_to_exec_file = linux_child_pid_to_exec_file; |
| t->to_post_startup_inferior = linux_child_post_startup_inferior; |
| t->to_post_attach = linux_child_post_attach; |
| t->to_follow_fork = linux_child_follow_fork; |
| t->to_find_memory_regions = linux_nat_find_memory_regions; |
| t->to_make_corefile_notes = linux_nat_make_corefile_notes; |
| |
| super_xfer_partial = t->to_xfer_partial; |
| t->to_xfer_partial = linux_xfer_partial; |
| } |
| |
| struct target_ops * |
| linux_target (void) |
| { |
| struct target_ops *t; |
| |
| t = inf_ptrace_target (); |
| linux_target_install_ops (t); |
| |
| return t; |
| } |
| |
| struct target_ops * |
| linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)) |
| { |
| struct target_ops *t; |
| |
| t = inf_ptrace_trad_target (register_u_offset); |
| linux_target_install_ops (t); |
| |
| return t; |
| } |
| |
| void |
| linux_nat_add_target (struct target_ops *t) |
| { |
| /* Save the provided single-threaded target. We save this in a separate |
| variable because another target we've inherited from (e.g. inf-ptrace) |
| may have saved a pointer to T; we want to use it for the final |
| process stratum target. */ |
| linux_ops_saved = *t; |
| linux_ops = &linux_ops_saved; |
| |
| /* Override some methods for multithreading. */ |
| t->to_attach = linux_nat_attach; |
| t->to_detach = linux_nat_detach; |
| t->to_resume = linux_nat_resume; |
| t->to_wait = linux_nat_wait; |
| t->to_xfer_partial = linux_nat_xfer_partial; |
| t->to_kill = linux_nat_kill; |
| t->to_mourn_inferior = linux_nat_mourn_inferior; |
| t->to_thread_alive = linux_nat_thread_alive; |
| t->to_pid_to_str = linux_nat_pid_to_str; |
| t->to_has_thread_control = tc_schedlock; |
| |
| /* We don't change the stratum; this target will sit at |
| process_stratum and thread_db will set at thread_stratum. This |
| is a little strange, since this is a multi-threaded-capable |
| target, but we want to be on the stack below thread_db, and we |
| also want to be used for single-threaded processes. */ |
| |
| add_target (t); |
| |
| /* TODO: Eliminate this and have libthread_db use |
| find_target_beneath. */ |
| thread_db_init (t); |
| } |
| |
| void |
| _initialize_linux_nat (void) |
| { |
| struct sigaction action; |
| |
| add_info ("proc", linux_nat_info_proc_cmd, _("\ |
| Show /proc process information about any running process.\n\ |
| Specify any process id, or use the program being debugged by default.\n\ |
| Specify any of the following keywords for detailed info:\n\ |
| mappings -- list of mapped memory regions.\n\ |
| stat -- list a bunch of random process info.\n\ |
| status -- list a different bunch of random process info.\n\ |
| all -- list all available /proc info.")); |
| |
| /* Save the original signal mask. */ |
| sigprocmask (SIG_SETMASK, NULL, &normal_mask); |
| |
| action.sa_handler = sigchld_handler; |
| sigemptyset (&action.sa_mask); |
| action.sa_flags = SA_RESTART; |
| sigaction (SIGCHLD, &action, NULL); |
| |
| /* Make sure we don't block SIGCHLD during a sigsuspend. */ |
| sigprocmask (SIG_SETMASK, NULL, &suspend_mask); |
| sigdelset (&suspend_mask, SIGCHLD); |
| |
| sigemptyset (&blocked_mask); |
| |
| add_setshow_zinteger_cmd ("lin-lwp", no_class, &debug_linux_nat, _("\ |
| Set debugging of GNU/Linux lwp module."), _("\ |
| Show debugging of GNU/Linux lwp module."), _("\ |
| Enables printf debugging output."), |
| NULL, |
| show_debug_linux_nat, |
| &setdebuglist, &showdebuglist); |
| } |
| |
| |
| /* FIXME: kettenis/2000-08-26: The stuff on this page is specific to |
| the GNU/Linux Threads library and therefore doesn't really belong |
| here. */ |
| |
| /* Read variable NAME in the target and return its value if found. |
| Otherwise return zero. It is assumed that the type of the variable |
| is `int'. */ |
| |
| static int |
| get_signo (const char *name) |
| { |
| struct minimal_symbol *ms; |
| int signo; |
| |
| ms = lookup_minimal_symbol (name, NULL, NULL); |
| if (ms == NULL) |
| return 0; |
| |
| if (target_read_memory (SYMBOL_VALUE_ADDRESS (ms), (gdb_byte *) &signo, |
| sizeof (signo)) != 0) |
| return 0; |
| |
| return signo; |
| } |
| |
| /* Return the set of signals used by the threads library in *SET. */ |
| |
| void |
| lin_thread_get_thread_signals (sigset_t *set) |
| { |
| struct sigaction action; |
| int restart, cancel; |
| |
| sigemptyset (set); |
| |
| restart = get_signo ("__pthread_sig_restart"); |
| cancel = get_signo ("__pthread_sig_cancel"); |
| |
| /* LinuxThreads normally uses the first two RT signals, but in some legacy |
| cases may use SIGUSR1/SIGUSR2. NPTL always uses RT signals, but does |
| not provide any way for the debugger to query the signal numbers - |
| fortunately they don't change! */ |
| |
| if (restart == 0) |
| restart = __SIGRTMIN; |
| |
| if (cancel == 0) |
| cancel = __SIGRTMIN + 1; |
| |
| sigaddset (set, restart); |
| sigaddset (set, cancel); |
| |
| /* The GNU/Linux Threads library makes terminating threads send a |
| special "cancel" signal instead of SIGCHLD. Make sure we catch |
| those (to prevent them from terminating GDB itself, which is |
| likely to be their default action) and treat them the same way as |
| SIGCHLD. */ |
| |
| action.sa_handler = sigchld_handler; |
| sigemptyset (&action.sa_mask); |
| action.sa_flags = SA_RESTART; |
| sigaction (cancel, &action, NULL); |
| |
| /* We block the "cancel" signal throughout this code ... */ |
| sigaddset (&blocked_mask, cancel); |
| sigprocmask (SIG_BLOCK, &blocked_mask, NULL); |
| |
| /* ... except during a sigsuspend. */ |
| sigdelset (&suspend_mask, cancel); |
| } |
| |