| 1 | /* Native debugging support for GNU/Linux (LWP layer). |
| 2 | |
| 3 | Copyright (C) 2000-2015 Free Software Foundation, Inc. |
| 4 | |
| 5 | This file is part of GDB. |
| 6 | |
| 7 | This program is free software; you can redistribute it and/or modify |
| 8 | it under the terms of the GNU General Public License as published by |
| 9 | the Free Software Foundation; either version 3 of the License, or |
| 10 | (at your option) any later version. |
| 11 | |
| 12 | This program is distributed in the hope that it will be useful, |
| 13 | but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | GNU General Public License for more details. |
| 16 | |
| 17 | You should have received a copy of the GNU General Public License |
| 18 | along with this program. If not, see <http://www.gnu.org/licenses/>. */ |
| 19 | |
| 20 | #include "nat/linux-nat.h" |
| 21 | #include "target.h" |
| 22 | #include <signal.h> |
| 23 | |
| 24 | struct arch_lwp_info; |
| 25 | |
| 26 | /* Structure describing an LWP. This is public only for the purposes |
| 27 | of ALL_LWPS; target-specific code should generally not access it |
| 28 | directly. */ |
| 29 | |
| 30 | struct lwp_info |
| 31 | { |
| 32 | /* The process id of the LWP. This is a combination of the LWP id |
| 33 | and overall process id. */ |
| 34 | ptid_t ptid; |
| 35 | |
| 36 | /* If this flag is set, we need to set the event request flags the |
| 37 | next time we see this LWP stop. */ |
| 38 | int must_set_ptrace_flags; |
| 39 | |
| 40 | /* Non-zero if this LWP is cloned. In this context "cloned" means |
| 41 | that the LWP is reporting to its parent using a signal other than |
| 42 | SIGCHLD. */ |
| 43 | int cloned; |
| 44 | |
| 45 | /* Non-zero if we sent this LWP a SIGSTOP (but the LWP didn't report |
| 46 | it back yet). */ |
| 47 | int signalled; |
| 48 | |
| 49 | /* Non-zero if this LWP is stopped. */ |
| 50 | int stopped; |
| 51 | |
| 52 | /* Non-zero if this LWP will be/has been resumed. Note that an LWP |
| 53 | can be marked both as stopped and resumed at the same time. This |
| 54 | happens if we try to resume an LWP that has a wait status |
| 55 | pending. We shouldn't let the LWP run until that wait status has |
| 56 | been processed, but we should not report that wait status if GDB |
| 57 | didn't try to let the LWP run. */ |
| 58 | int resumed; |
| 59 | |
| 60 | /* The last resume GDB requested on this thread. */ |
| 61 | enum resume_kind last_resume_kind; |
| 62 | |
| 63 | /* If non-zero, a pending wait status. */ |
| 64 | int status; |
| 65 | |
| 66 | /* When 'stopped' is set, this is where the lwp last stopped, with |
| 67 | decr_pc_after_break already accounted for. If the LWP is |
| 68 | running, and stepping, this is the address at which the lwp was |
| 69 | resumed (that is, it's the previous stop PC). If the LWP is |
| 70 | running and not stepping, this is 0. */ |
| 71 | CORE_ADDR stop_pc; |
| 72 | |
| 73 | /* Non-zero if we were stepping this LWP. */ |
| 74 | int step; |
| 75 | |
| 76 | /* The reason the LWP last stopped, if we need to track it |
| 77 | (breakpoint, watchpoint, etc.) */ |
| 78 | enum target_stop_reason stop_reason; |
| 79 | |
| 80 | /* On architectures where it is possible to know the data address of |
| 81 | a triggered watchpoint, STOPPED_DATA_ADDRESS_P is non-zero, and |
| 82 | STOPPED_DATA_ADDRESS contains such data address. Otherwise, |
| 83 | STOPPED_DATA_ADDRESS_P is false, and STOPPED_DATA_ADDRESS is |
| 84 | undefined. Only valid if STOPPED_BY_WATCHPOINT is true. */ |
| 85 | int stopped_data_address_p; |
| 86 | CORE_ADDR stopped_data_address; |
| 87 | |
| 88 | /* Non-zero if we expect a duplicated SIGINT. */ |
| 89 | int ignore_sigint; |
| 90 | |
| 91 | /* If WAITSTATUS->KIND != TARGET_WAITKIND_SPURIOUS, the waitstatus |
| 92 | for this LWP's last event. This may correspond to STATUS above, |
| 93 | or to a local variable in lin_lwp_wait. */ |
| 94 | struct target_waitstatus waitstatus; |
| 95 | |
| 96 | /* Signal wether we are in a SYSCALL_ENTRY or |
| 97 | in a SYSCALL_RETURN event. |
| 98 | Values: |
| 99 | - TARGET_WAITKIND_SYSCALL_ENTRY |
| 100 | - TARGET_WAITKIND_SYSCALL_RETURN */ |
| 101 | enum target_waitkind syscall_state; |
| 102 | |
| 103 | /* The processor core this LWP was last seen on. */ |
| 104 | int core; |
| 105 | |
| 106 | /* Arch-specific additions. */ |
| 107 | struct arch_lwp_info *arch_private; |
| 108 | |
| 109 | /* Next LWP in list. */ |
| 110 | struct lwp_info *next; |
| 111 | }; |
| 112 | |
| 113 | /* The global list of LWPs, for ALL_LWPS. Unlike the threads list, |
| 114 | there is always at least one LWP on the list while the GNU/Linux |
| 115 | native target is active. */ |
| 116 | extern struct lwp_info *lwp_list; |
| 117 | |
| 118 | /* Does the current host support PTRACE_GETREGSET? */ |
| 119 | extern enum tribool have_ptrace_getregset; |
| 120 | |
| 121 | /* Iterate over each active thread (light-weight process). */ |
| 122 | #define ALL_LWPS(LP) \ |
| 123 | for ((LP) = lwp_list; \ |
| 124 | (LP) != NULL; \ |
| 125 | (LP) = (LP)->next) |
| 126 | |
| 127 | /* Attempt to initialize libthread_db. */ |
| 128 | void check_for_thread_db (void); |
| 129 | |
| 130 | /* Called from the LWP layer to inform the thread_db layer that PARENT |
| 131 | spawned CHILD. Both LWPs are currently stopped. This function |
| 132 | does whatever is required to have the child LWP under the |
| 133 | thread_db's control --- e.g., enabling event reporting. Returns |
| 134 | true on success, false if the process isn't using libpthread. */ |
| 135 | extern int thread_db_notice_clone (ptid_t parent, ptid_t child); |
| 136 | |
| 137 | /* Return the set of signals used by the threads library. */ |
| 138 | extern void lin_thread_get_thread_signals (sigset_t *mask); |
| 139 | |
| 140 | /* Find process PID's pending signal set from /proc/pid/status. */ |
| 141 | void linux_proc_pending_signals (int pid, sigset_t *pending, |
| 142 | sigset_t *blocked, sigset_t *ignored); |
| 143 | |
| 144 | extern int lin_lwp_attach_lwp (ptid_t ptid); |
| 145 | |
| 146 | /* For linux_stop_lwp see nat/linux-nat.h. */ |
| 147 | |
| 148 | /* Stop all LWPs, synchronously. (Any events that trigger while LWPs |
| 149 | are being stopped are left pending.) */ |
| 150 | extern void linux_stop_and_wait_all_lwps (void); |
| 151 | |
| 152 | /* Set resumed LWPs running again, as they were before being stopped |
| 153 | with linux_stop_and_wait_all_lwps. (LWPS with pending events are |
| 154 | left stopped.) */ |
| 155 | extern void linux_unstop_all_lwps (void); |
| 156 | |
| 157 | /* Create a prototype generic GNU/Linux target. The client can |
| 158 | override it with local methods. */ |
| 159 | struct target_ops * linux_target (void); |
| 160 | |
| 161 | /* Create a generic GNU/Linux target using traditional |
| 162 | ptrace register access. */ |
| 163 | struct target_ops * |
| 164 | linux_trad_target (CORE_ADDR (*register_u_offset)(struct gdbarch *, int, int)); |
| 165 | |
| 166 | /* Register the customized GNU/Linux target. This should be used |
| 167 | instead of calling add_target directly. */ |
| 168 | void linux_nat_add_target (struct target_ops *); |
| 169 | |
| 170 | /* Register a method to call whenever a new thread is attached. */ |
| 171 | void linux_nat_set_new_thread (struct target_ops *, void (*) (struct lwp_info *)); |
| 172 | |
| 173 | |
| 174 | /* Register a method to call whenever a new fork is attached. */ |
| 175 | typedef void (linux_nat_new_fork_ftype) (struct lwp_info *parent, |
| 176 | pid_t child_pid); |
| 177 | void linux_nat_set_new_fork (struct target_ops *ops, |
| 178 | linux_nat_new_fork_ftype *fn); |
| 179 | |
| 180 | /* Register a method to call whenever a process is killed or |
| 181 | detached. */ |
| 182 | typedef void (linux_nat_forget_process_ftype) (pid_t pid); |
| 183 | void linux_nat_set_forget_process (struct target_ops *ops, |
| 184 | linux_nat_forget_process_ftype *fn); |
| 185 | |
| 186 | /* Call the method registered with the function above. PID is the |
| 187 | process to forget about. */ |
| 188 | void linux_nat_forget_process (pid_t pid); |
| 189 | |
| 190 | /* Register a method that converts a siginfo object between the layout |
| 191 | that ptrace returns, and the layout in the architecture of the |
| 192 | inferior. */ |
| 193 | void linux_nat_set_siginfo_fixup (struct target_ops *, |
| 194 | int (*) (siginfo_t *, |
| 195 | gdb_byte *, |
| 196 | int)); |
| 197 | |
| 198 | /* Register a method to call prior to resuming a thread. */ |
| 199 | |
| 200 | void linux_nat_set_prepare_to_resume (struct target_ops *, |
| 201 | void (*) (struct lwp_info *)); |
| 202 | |
| 203 | /* Update linux-nat internal state when changing from one fork |
| 204 | to another. */ |
| 205 | void linux_nat_switch_fork (ptid_t new_ptid); |
| 206 | |
| 207 | /* Store the saved siginfo associated with PTID in *SIGINFO. |
| 208 | Return 1 if it was retrieved successfully, 0 otherwise (*SIGINFO is |
| 209 | uninitialized in such case). */ |
| 210 | int linux_nat_get_siginfo (ptid_t ptid, siginfo_t *siginfo); |
| 211 | |
| 212 | /* Set alternative SIGTRAP-like events recognizer. */ |
| 213 | void linux_nat_set_status_is_event (struct target_ops *t, |
| 214 | int (*status_is_event) (int status)); |