| /* Native-dependent code for FreeBSD. |
| |
| Copyright (C) 2002-2015 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 3 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, see <http://www.gnu.org/licenses/>. */ |
| |
| #include "defs.h" |
| #include "gdbcore.h" |
| #include "inferior.h" |
| #include "regcache.h" |
| #include "regset.h" |
| #include "gdbthread.h" |
| #include "gdb_wait.h" |
| #include <sys/types.h> |
| #include <sys/procfs.h> |
| #include <sys/ptrace.h> |
| #include <sys/sysctl.h> |
| #ifdef HAVE_KINFO_GETVMMAP |
| #include <sys/user.h> |
| #include <libutil.h> |
| #endif |
| |
| #include "elf-bfd.h" |
| #include "fbsd-nat.h" |
| |
| /* Return the name of a file that can be opened to get the symbols for |
| the child process identified by PID. */ |
| |
| static char * |
| fbsd_pid_to_exec_file (struct target_ops *self, int pid) |
| { |
| ssize_t len = PATH_MAX; |
| static char buf[PATH_MAX]; |
| char name[PATH_MAX]; |
| |
| #ifdef KERN_PROC_PATHNAME |
| int mib[4]; |
| |
| mib[0] = CTL_KERN; |
| mib[1] = KERN_PROC; |
| mib[2] = KERN_PROC_PATHNAME; |
| mib[3] = pid; |
| if (sysctl (mib, 4, buf, &len, NULL, 0) == 0) |
| return buf; |
| #endif |
| |
| xsnprintf (name, PATH_MAX, "/proc/%d/exe", pid); |
| len = readlink (name, buf, PATH_MAX - 1); |
| if (len != -1) |
| { |
| buf[len] = '\0'; |
| return buf; |
| } |
| |
| return NULL; |
| } |
| |
| #ifdef HAVE_KINFO_GETVMMAP |
| /* Iterate over all the memory regions in the current inferior, |
| calling FUNC for each memory region. OBFD is passed as the last |
| argument to FUNC. */ |
| |
| static int |
| fbsd_find_memory_regions (struct target_ops *self, |
| find_memory_region_ftype func, void *obfd) |
| { |
| pid_t pid = ptid_get_pid (inferior_ptid); |
| struct kinfo_vmentry *vmentl, *kve; |
| uint64_t size; |
| struct cleanup *cleanup; |
| int i, nitems; |
| |
| vmentl = kinfo_getvmmap (pid, &nitems); |
| if (vmentl == NULL) |
| perror_with_name (_("Couldn't fetch VM map entries.")); |
| cleanup = make_cleanup (free, vmentl); |
| |
| for (i = 0; i < nitems; i++) |
| { |
| kve = &vmentl[i]; |
| |
| /* Skip unreadable segments and those where MAP_NOCORE has been set. */ |
| if (!(kve->kve_protection & KVME_PROT_READ) |
| || kve->kve_flags & KVME_FLAG_NOCOREDUMP) |
| continue; |
| |
| /* Skip segments with an invalid type. */ |
| if (kve->kve_type != KVME_TYPE_DEFAULT |
| && kve->kve_type != KVME_TYPE_VNODE |
| && kve->kve_type != KVME_TYPE_SWAP |
| && kve->kve_type != KVME_TYPE_PHYS) |
| continue; |
| |
| size = kve->kve_end - kve->kve_start; |
| if (info_verbose) |
| { |
| fprintf_filtered (gdb_stdout, |
| "Save segment, %ld bytes at %s (%c%c%c)\n", |
| (long) size, |
| paddress (target_gdbarch (), kve->kve_start), |
| kve->kve_protection & KVME_PROT_READ ? 'r' : '-', |
| kve->kve_protection & KVME_PROT_WRITE ? 'w' : '-', |
| kve->kve_protection & KVME_PROT_EXEC ? 'x' : '-'); |
| } |
| |
| /* Invoke the callback function to create the corefile segment. |
| Pass MODIFIED as true, we do not know the real modification state. */ |
| func (kve->kve_start, size, kve->kve_protection & KVME_PROT_READ, |
| kve->kve_protection & KVME_PROT_WRITE, |
| kve->kve_protection & KVME_PROT_EXEC, 1, obfd); |
| } |
| do_cleanups (cleanup); |
| return 0; |
| } |
| #else |
| static int |
| fbsd_read_mapping (FILE *mapfile, unsigned long *start, unsigned long *end, |
| char *protection) |
| { |
| /* FreeBSD 5.1-RELEASE uses a 256-byte buffer. */ |
| char buf[256]; |
| int resident, privateresident; |
| unsigned long obj; |
| int ret = EOF; |
| |
| /* As of FreeBSD 5.0-RELEASE, the layout is described in |
| /usr/src/sys/fs/procfs/procfs_map.c. Somewhere in 5.1-CURRENT a |
| new column was added to the procfs map. Therefore we can't use |
| fscanf since we need to support older releases too. */ |
| if (fgets (buf, sizeof buf, mapfile) != NULL) |
| ret = sscanf (buf, "%lx %lx %d %d %lx %s", start, end, |
| &resident, &privateresident, &obj, protection); |
| |
| return (ret != 0 && ret != EOF); |
| } |
| |
| /* Iterate over all the memory regions in the current inferior, |
| calling FUNC for each memory region. OBFD is passed as the last |
| argument to FUNC. */ |
| |
| static int |
| fbsd_find_memory_regions (struct target_ops *self, |
| find_memory_region_ftype func, void *obfd) |
| { |
| pid_t pid = ptid_get_pid (inferior_ptid); |
| char *mapfilename; |
| FILE *mapfile; |
| unsigned long start, end, size; |
| char protection[4]; |
| int read, write, exec; |
| struct cleanup *cleanup; |
| |
| mapfilename = xstrprintf ("/proc/%ld/map", (long) pid); |
| cleanup = make_cleanup (xfree, mapfilename); |
| mapfile = fopen (mapfilename, "r"); |
| if (mapfile == NULL) |
| error (_("Couldn't open %s."), mapfilename); |
| make_cleanup_fclose (mapfile); |
| |
| if (info_verbose) |
| fprintf_filtered (gdb_stdout, |
| "Reading memory regions from %s\n", mapfilename); |
| |
| /* Now iterate until end-of-file. */ |
| while (fbsd_read_mapping (mapfile, &start, &end, &protection[0])) |
| { |
| size = end - start; |
| |
| read = (strchr (protection, 'r') != 0); |
| write = (strchr (protection, 'w') != 0); |
| exec = (strchr (protection, 'x') != 0); |
| |
| if (info_verbose) |
| { |
| fprintf_filtered (gdb_stdout, |
| "Save segment, %ld bytes at %s (%c%c%c)\n", |
| size, paddress (target_gdbarch (), start), |
| read ? 'r' : '-', |
| write ? 'w' : '-', |
| exec ? 'x' : '-'); |
| } |
| |
| /* Invoke the callback function to create the corefile segment. |
| Pass MODIFIED as true, we do not know the real modification state. */ |
| func (start, size, read, write, exec, 1, obfd); |
| } |
| |
| do_cleanups (cleanup); |
| return 0; |
| } |
| #endif |
| |
| #ifdef PT_LWPINFO |
| static ptid_t (*super_wait) (struct target_ops *, |
| ptid_t, |
| struct target_waitstatus *, |
| int); |
| |
| #ifdef TDP_RFPPWAIT |
| /* |
| To catch fork events, PT_FOLLOW_FORK is set on every traced process |
| to enable stops on returns from fork or vfork. Note that both the |
| parent and child will always stop, even if system call stops are not |
| enabled. |
| |
| After a fork, both the child and parent process will stop and report |
| an event. However, there is no guarantee of order. If the parent |
| reports its stop first, then fbsd_wait explicitly waits for the new |
| child before returning. If the child reports its stop first, then |
| the event is saved on a list and ignored until the parent's stop is |
| reported. fbsd_wait could have been changed to fetch the parent PID |
| of the new child and used that to wait for the parent explicitly. |
| However, if two threads in the parent fork at the same time, then |
| the wait on the parent might return the "wrong" fork event. |
| |
| The initial version of PT_FOLLOW_FORK did not set PL_FLAG_CHILD for |
| the new child process. This flag could be inferred by treating any |
| events for an unknown pid as a new child. |
| |
| In addition, the initial version of PT_FOLLOW_FORK did not report a |
| stop event for the parent process of a vfork until after the child |
| process executed a new program or exited. The kernel was changed to |
| defer the wait for exit or exec of the child until after posting the |
| stop event shortly after the change to introduce PL_FLAG_CHILD. |
| This could be worked around by reporting a vfork event when the |
| child event posted and ignoring the subsequent event from the |
| parent. |
| |
| This implementation requires both of these fixes for simplicity's |
| sake. FreeBSD versions newer than 9.1 contain both fixes. |
| */ |
| |
| struct fbsd_fork_child_info |
| { |
| struct fbsd_fork_child_info *next; |
| pid_t child; /* Pid of new child. */ |
| }; |
| |
| static struct fbsd_fork_child_info *fbsd_pending_children; |
| |
| /* Record a new child process event that is reported before the |
| corresponding fork event in the parent. */ |
| |
| static void |
| fbsd_remember_child (pid_t pid) |
| { |
| struct fbsd_fork_child_info *info = XCNEW (struct fbsd_fork_child_info); |
| |
| info->child = pid; |
| info->next = fbsd_pending_children; |
| fbsd_pending_children = info; |
| } |
| |
| /* Check for a previously-recorded new child process event for PID. |
| If one is found, remove it from the list. */ |
| |
| static int |
| fbsd_is_child_pending (pid_t pid) |
| { |
| struct fbsd_fork_child_info *info, *prev; |
| |
| prev = NULL; |
| for (info = fbsd_pending_children; info; prev = info, info = info->next) |
| { |
| if (info->child == pid) |
| { |
| if (prev == NULL) |
| fbsd_pending_children = info->next; |
| else |
| prev->next = info->next; |
| xfree (info); |
| return 1; |
| } |
| } |
| return 0; |
| } |
| |
| /* Fetch the external variant of the kernel's internal process |
| structure for the process PID into KP. */ |
| |
| static void |
| fbsd_fetch_kinfo_proc (pid_t pid, struct kinfo_proc *kp) |
| { |
| size_t len; |
| int mib[4]; |
| |
| len = sizeof *kp; |
| mib[0] = CTL_KERN; |
| mib[1] = KERN_PROC; |
| mib[2] = KERN_PROC_PID; |
| mib[3] = pid; |
| if (sysctl (mib, 4, kp, &len, NULL, 0) == -1) |
| perror_with_name (("sysctl")); |
| } |
| #endif |
| |
| /* Wait for the child specified by PTID to do something. Return the |
| process ID of the child, or MINUS_ONE_PTID in case of error; store |
| the status in *OURSTATUS. */ |
| |
| static ptid_t |
| fbsd_wait (struct target_ops *ops, |
| ptid_t ptid, struct target_waitstatus *ourstatus, |
| int target_options) |
| { |
| ptid_t wptid; |
| |
| while (1) |
| { |
| wptid = super_wait (ops, ptid, ourstatus, target_options); |
| if (ourstatus->kind == TARGET_WAITKIND_STOPPED) |
| { |
| struct ptrace_lwpinfo pl; |
| pid_t pid; |
| int status; |
| |
| pid = ptid_get_pid (wptid); |
| if (ptrace (PT_LWPINFO, pid, (caddr_t)&pl, sizeof pl) == -1) |
| perror_with_name (("ptrace")); |
| |
| #ifdef TDP_RFPPWAIT |
| if (pl.pl_flags & PL_FLAG_FORKED) |
| { |
| struct kinfo_proc kp; |
| pid_t child; |
| |
| child = pl.pl_child_pid; |
| ourstatus->kind = TARGET_WAITKIND_FORKED; |
| ourstatus->value.related_pid = pid_to_ptid (child); |
| |
| /* Make sure the other end of the fork is stopped too. */ |
| if (!fbsd_is_child_pending (child)) |
| { |
| pid = waitpid (child, &status, 0); |
| if (pid == -1) |
| perror_with_name (("waitpid")); |
| |
| gdb_assert (pid == child); |
| |
| if (ptrace (PT_LWPINFO, child, (caddr_t)&pl, sizeof pl) == -1) |
| perror_with_name (("ptrace")); |
| |
| gdb_assert (pl.pl_flags & PL_FLAG_CHILD); |
| } |
| |
| /* For vfork, the child process will have the P_PPWAIT |
| flag set. */ |
| fbsd_fetch_kinfo_proc (child, &kp); |
| if (kp.ki_flag & P_PPWAIT) |
| ourstatus->kind = TARGET_WAITKIND_VFORKED; |
| |
| return wptid; |
| } |
| |
| if (pl.pl_flags & PL_FLAG_CHILD) |
| { |
| /* Remember that this child forked, but do not report it |
| until the parent reports its corresponding fork |
| event. */ |
| fbsd_remember_child (ptid_get_pid (wptid)); |
| continue; |
| } |
| #endif |
| |
| #ifdef PL_FLAG_EXEC |
| if (pl.pl_flags & PL_FLAG_EXEC) |
| { |
| ourstatus->kind = TARGET_WAITKIND_EXECD; |
| ourstatus->value.execd_pathname |
| = xstrdup (fbsd_pid_to_exec_file (NULL, pid)); |
| return wptid; |
| } |
| #endif |
| } |
| return wptid; |
| } |
| } |
| |
| #ifdef TDP_RFPPWAIT |
| /* Target hook for follow_fork. On entry and at return inferior_ptid is |
| the ptid of the followed inferior. */ |
| |
| static int |
| fbsd_follow_fork (struct target_ops *ops, int follow_child, |
| int detach_fork) |
| { |
| if (!follow_child) |
| { |
| struct thread_info *tp = inferior_thread (); |
| pid_t child_pid = ptid_get_pid (tp->pending_follow.value.related_pid); |
| |
| /* Breakpoints have already been detached from the child by |
| infrun.c. */ |
| |
| if (ptrace (PT_DETACH, child_pid, (PTRACE_TYPE_ARG3)1, 0) == -1) |
| perror_with_name (("ptrace")); |
| } |
| |
| return 0; |
| } |
| |
| static int |
| fbsd_insert_fork_catchpoint (struct target_ops *self, int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| fbsd_remove_fork_catchpoint (struct target_ops *self, int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| fbsd_insert_vfork_catchpoint (struct target_ops *self, int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| fbsd_remove_vfork_catchpoint (struct target_ops *self, int pid) |
| { |
| return 0; |
| } |
| |
| /* Enable fork tracing for a specific process. |
| |
| To catch fork events, PT_FOLLOW_FORK is set on every traced process |
| to enable stops on returns from fork or vfork. Note that both the |
| parent and child will always stop, even if system call stops are |
| not enabled. */ |
| |
| static void |
| fbsd_enable_follow_fork (pid_t pid) |
| { |
| if (ptrace (PT_FOLLOW_FORK, pid, (PTRACE_TYPE_ARG3)0, 1) == -1) |
| perror_with_name (("ptrace")); |
| } |
| |
| /* Implement the "to_post_startup_inferior" target_ops method. */ |
| |
| static void |
| fbsd_post_startup_inferior (struct target_ops *self, ptid_t pid) |
| { |
| fbsd_enable_follow_fork (ptid_get_pid (pid)); |
| } |
| |
| /* Implement the "to_post_attach" target_ops method. */ |
| |
| static void |
| fbsd_post_attach (struct target_ops *self, int pid) |
| { |
| fbsd_enable_follow_fork (pid); |
| } |
| #endif |
| |
| #ifdef PL_FLAG_EXEC |
| /* If the FreeBSD kernel supports PL_FLAG_EXEC, then traced processes |
| will always stop after exec. */ |
| |
| static int |
| fbsd_insert_exec_catchpoint (struct target_ops *self, int pid) |
| { |
| return 0; |
| } |
| |
| static int |
| fbsd_remove_exec_catchpoint (struct target_ops *self, int pid) |
| { |
| return 0; |
| } |
| #endif |
| #endif |
| |
| void |
| fbsd_nat_add_target (struct target_ops *t) |
| { |
| t->to_pid_to_exec_file = fbsd_pid_to_exec_file; |
| t->to_find_memory_regions = fbsd_find_memory_regions; |
| #ifdef PT_LWPINFO |
| super_wait = t->to_wait; |
| t->to_wait = fbsd_wait; |
| #ifdef TDP_RFPPWAIT |
| t->to_follow_fork = fbsd_follow_fork; |
| t->to_insert_fork_catchpoint = fbsd_insert_fork_catchpoint; |
| t->to_remove_fork_catchpoint = fbsd_remove_fork_catchpoint; |
| t->to_insert_vfork_catchpoint = fbsd_insert_vfork_catchpoint; |
| t->to_remove_vfork_catchpoint = fbsd_remove_vfork_catchpoint; |
| t->to_post_startup_inferior = fbsd_post_startup_inferior; |
| t->to_post_attach = fbsd_post_attach; |
| #endif |
| #ifdef PL_FLAG_EXEC |
| t->to_insert_exec_catchpoint = fbsd_insert_exec_catchpoint; |
| t->to_remove_exec_catchpoint = fbsd_remove_exec_catchpoint; |
| #endif |
| #endif |
| add_target (t); |
| } |