/* Native-dependent code for FreeBSD. Copyright (C) 2002-2018 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 . */ #include "defs.h" #include "byte-vector.h" #include "gdbcore.h" #include "inferior.h" #include "regcache.h" #include "regset.h" #include "gdbcmd.h" #include "gdbthread.h" #include "gdb_wait.h" #include #include #include #include #include #include #if defined(HAVE_KINFO_GETFILE) || defined(HAVE_KINFO_GETVMMAP) #include #endif #if !defined(HAVE_KINFO_GETVMMAP) #include "filestuff.h" #endif #include "elf-bfd.h" #include "fbsd-nat.h" #include "fbsd-tdep.h" #include /* 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; static char buf[PATH_MAX]; char name[PATH_MAX]; #ifdef KERN_PROC_PATHNAME size_t buflen; int mib[4]; mib[0] = CTL_KERN; mib[1] = KERN_PROC; mib[2] = KERN_PROC_PATHNAME; mib[3] = pid; buflen = sizeof buf; if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0) /* The kern.proc.pathname. sysctl returns a length of zero for processes without an associated executable such as kernel processes. */ return buflen == 0 ? NULL : 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 *kve; uint64_t size; int i, nitems; gdb::unique_xmalloc_ptr vmentl (kinfo_getvmmap (pid, &nitems)); if (vmentl == NULL) perror_with_name (_("Couldn't fetch VM map entries.")); for (i = 0, kve = vmentl.get (); i < nitems; i++, kve++) { /* 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); } 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); unsigned long start, end, size; char protection[4]; int read, write, exec; std::string mapfilename = string_printf ("/proc/%ld/map", (long) pid); gdb_file_up mapfile (fopen (mapfilename.c_str (), "r")); if (mapfile == NULL) error (_("Couldn't open %s."), mapfilename.c_str ()); if (info_verbose) fprintf_filtered (gdb_stdout, "Reading memory regions from %s\n", mapfilename.c_str ()); /* Now iterate until end-of-file. */ while (fbsd_read_mapping (mapfile.get (), &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); } return 0; } #endif /* Fetch the command line for a running process. */ static gdb::unique_xmalloc_ptr fbsd_fetch_cmdline (pid_t pid) { size_t len; int mib[4]; len = 0; mib[0] = CTL_KERN; mib[1] = KERN_PROC; mib[2] = KERN_PROC_ARGS; mib[3] = pid; if (sysctl (mib, 4, NULL, &len, NULL, 0) == -1) return nullptr; if (len == 0) return nullptr; gdb::unique_xmalloc_ptr cmdline ((char *) xmalloc (len)); if (sysctl (mib, 4, cmdline.get (), &len, NULL, 0) == -1) return nullptr; return cmdline; } /* Fetch the external variant of the kernel's internal process structure for the process PID into KP. */ static bool 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; return (sysctl (mib, 4, kp, &len, NULL, 0) == 0); } /* Implement the "to_info_proc target_ops" method. */ static void fbsd_info_proc (struct target_ops *ops, const char *args, enum info_proc_what what) { #ifdef HAVE_KINFO_GETFILE gdb::unique_xmalloc_ptr fdtbl; int nfd = 0; #endif struct kinfo_proc kp; char *tmp; pid_t pid; bool do_cmdline = false; bool do_cwd = false; bool do_exe = false; #ifdef HAVE_KINFO_GETVMMAP bool do_mappings = false; #endif bool do_status = false; switch (what) { case IP_MINIMAL: do_cmdline = true; do_cwd = true; do_exe = true; break; #ifdef HAVE_KINFO_GETVMMAP case IP_MAPPINGS: do_mappings = true; break; #endif case IP_STATUS: case IP_STAT: do_status = true; break; case IP_CMDLINE: do_cmdline = true; break; case IP_EXE: do_exe = true; break; case IP_CWD: do_cwd = true; break; case IP_ALL: do_cmdline = true; do_cwd = true; do_exe = true; #ifdef HAVE_KINFO_GETVMMAP do_mappings = true; #endif do_status = true; break; default: error (_("Not supported on this target.")); } gdb_argv built_argv (args); if (built_argv.count () == 0) { pid = ptid_get_pid (inferior_ptid); if (pid == 0) error (_("No current process: you must name one.")); } else if (built_argv.count () == 1 && isdigit (built_argv[0][0])) pid = strtol (built_argv[0], NULL, 10); else error (_("Invalid arguments.")); printf_filtered (_("process %d\n"), pid); #ifdef HAVE_KINFO_GETFILE if (do_cwd || do_exe) fdtbl.reset (kinfo_getfile (pid, &nfd)); #endif if (do_cmdline) { gdb::unique_xmalloc_ptr cmdline = fbsd_fetch_cmdline (pid); if (cmdline != nullptr) printf_filtered ("cmdline = '%s'\n", cmdline.get ()); else warning (_("unable to fetch command line")); } if (do_cwd) { const char *cwd = NULL; #ifdef HAVE_KINFO_GETFILE struct kinfo_file *kf = fdtbl.get (); for (int i = 0; i < nfd; i++, kf++) { if (kf->kf_type == KF_TYPE_VNODE && kf->kf_fd == KF_FD_TYPE_CWD) { cwd = kf->kf_path; break; } } #endif if (cwd != NULL) printf_filtered ("cwd = '%s'\n", cwd); else warning (_("unable to fetch current working directory")); } if (do_exe) { const char *exe = NULL; #ifdef HAVE_KINFO_GETFILE struct kinfo_file *kf = fdtbl.get (); for (int i = 0; i < nfd; i++, kf++) { if (kf->kf_type == KF_TYPE_VNODE && kf->kf_fd == KF_FD_TYPE_TEXT) { exe = kf->kf_path; break; } } #endif if (exe == NULL) exe = fbsd_pid_to_exec_file (ops, pid); if (exe != NULL) printf_filtered ("exe = '%s'\n", exe); else warning (_("unable to fetch executable path name")); } #ifdef HAVE_KINFO_GETVMMAP if (do_mappings) { int nvment; gdb::unique_xmalloc_ptr vmentl (kinfo_getvmmap (pid, &nvment)); if (vmentl != nullptr) { printf_filtered (_("Mapped address spaces:\n\n")); #ifdef __LP64__ printf_filtered (" %18s %18s %10s %10s %9s %s\n", "Start Addr", " End Addr", " Size", " Offset", "Flags ", "File"); #else printf_filtered ("\t%10s %10s %10s %10s %9s %s\n", "Start Addr", " End Addr", " Size", " Offset", "Flags ", "File"); #endif struct kinfo_vmentry *kve = vmentl.get (); for (int i = 0; i < nvment; i++, kve++) { ULONGEST start, end; start = kve->kve_start; end = kve->kve_end; #ifdef __LP64__ printf_filtered (" %18s %18s %10s %10s %9s %s\n", hex_string (start), hex_string (end), hex_string (end - start), hex_string (kve->kve_offset), fbsd_vm_map_entry_flags (kve->kve_flags, kve->kve_protection), kve->kve_path); #else printf_filtered ("\t%10s %10s %10s %10s %9s %s\n", hex_string (start), hex_string (end), hex_string (end - start), hex_string (kve->kve_offset), fbsd_vm_map_entry_flags (kve->kve_flags, kve->kve_protection), kve->kve_path); #endif } } else warning (_("unable to fetch virtual memory map")); } #endif if (do_status) { if (!fbsd_fetch_kinfo_proc (pid, &kp)) warning (_("Failed to fetch process information")); else { const char *state; int pgtok; printf_filtered ("Name: %s\n", kp.ki_comm); switch (kp.ki_stat) { case SIDL: state = "I (idle)"; break; case SRUN: state = "R (running)"; break; case SSTOP: state = "T (stopped)"; break; case SZOMB: state = "Z (zombie)"; break; case SSLEEP: state = "S (sleeping)"; break; case SWAIT: state = "W (interrupt wait)"; break; case SLOCK: state = "L (blocked on lock)"; break; default: state = "? (unknown)"; break; } printf_filtered ("State: %s\n", state); printf_filtered ("Parent process: %d\n", kp.ki_ppid); printf_filtered ("Process group: %d\n", kp.ki_pgid); printf_filtered ("Session id: %d\n", kp.ki_sid); printf_filtered ("TTY: %ju\n", (uintmax_t) kp.ki_tdev); printf_filtered ("TTY owner process group: %d\n", kp.ki_tpgid); printf_filtered ("User IDs (real, effective, saved): %d %d %d\n", kp.ki_ruid, kp.ki_uid, kp.ki_svuid); printf_filtered ("Group IDs (real, effective, saved): %d %d %d\n", kp.ki_rgid, kp.ki_groups[0], kp.ki_svgid); printf_filtered ("Groups: "); for (int i = 0; i < kp.ki_ngroups; i++) printf_filtered ("%d ", kp.ki_groups[i]); printf_filtered ("\n"); printf_filtered ("Minor faults (no memory page): %ld\n", kp.ki_rusage.ru_minflt); printf_filtered ("Minor faults, children: %ld\n", kp.ki_rusage_ch.ru_minflt); printf_filtered ("Major faults (memory page faults): %ld\n", kp.ki_rusage.ru_majflt); printf_filtered ("Major faults, children: %ld\n", kp.ki_rusage_ch.ru_majflt); printf_filtered ("utime: %jd.%06ld\n", (intmax_t) kp.ki_rusage.ru_utime.tv_sec, kp.ki_rusage.ru_utime.tv_usec); printf_filtered ("stime: %jd.%06ld\n", (intmax_t) kp.ki_rusage.ru_stime.tv_sec, kp.ki_rusage.ru_stime.tv_usec); printf_filtered ("utime, children: %jd.%06ld\n", (intmax_t) kp.ki_rusage_ch.ru_utime.tv_sec, kp.ki_rusage_ch.ru_utime.tv_usec); printf_filtered ("stime, children: %jd.%06ld\n", (intmax_t) kp.ki_rusage_ch.ru_stime.tv_sec, kp.ki_rusage_ch.ru_stime.tv_usec); printf_filtered ("'nice' value: %d\n", kp.ki_nice); printf_filtered ("Start time: %jd.%06ld\n", kp.ki_start.tv_sec, kp.ki_start.tv_usec); pgtok = getpagesize () / 1024; printf_filtered ("Virtual memory size: %ju kB\n", (uintmax_t) kp.ki_size / 1024); printf_filtered ("Data size: %ju kB\n", (uintmax_t) kp.ki_dsize * pgtok); printf_filtered ("Stack size: %ju kB\n", (uintmax_t) kp.ki_ssize * pgtok); printf_filtered ("Text size: %ju kB\n", (uintmax_t) kp.ki_tsize * pgtok); printf_filtered ("Resident set size: %ju kB\n", (uintmax_t) kp.ki_rssize * pgtok); printf_filtered ("Maximum RSS: %ju kB\n", (uintmax_t) kp.ki_rusage.ru_maxrss); printf_filtered ("Pending Signals: "); for (int i = 0; i < _SIG_WORDS; i++) printf_filtered ("%08x ", kp.ki_siglist.__bits[i]); printf_filtered ("\n"); printf_filtered ("Ignored Signals: "); for (int i = 0; i < _SIG_WORDS; i++) printf_filtered ("%08x ", kp.ki_sigignore.__bits[i]); printf_filtered ("\n"); printf_filtered ("Caught Signals: "); for (int i = 0; i < _SIG_WORDS; i++) printf_filtered ("%08x ", kp.ki_sigcatch.__bits[i]); printf_filtered ("\n"); } } } #ifdef KERN_PROC_AUXV static enum target_xfer_status (*super_xfer_partial) (struct target_ops *ops, enum target_object object, const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, ULONGEST *xfered_len); #ifdef PT_LWPINFO /* Return the size of siginfo for the current inferior. */ #ifdef __LP64__ union sigval32 { int sival_int; uint32_t sival_ptr; }; /* This structure matches the naming and layout of `siginfo_t' in . In particular, the `si_foo' macros defined in that header can be used with both types to copy fields in the `_reason' union. */ struct siginfo32 { int si_signo; int si_errno; int si_code; __pid_t si_pid; __uid_t si_uid; int si_status; uint32_t si_addr; union sigval32 si_value; union { struct { int _trapno; } _fault; struct { int _timerid; int _overrun; } _timer; struct { int _mqd; } _mesgq; struct { int32_t _band; } _poll; struct { int32_t __spare1__; int __spare2__[7]; } __spare__; } _reason; }; #endif static size_t fbsd_siginfo_size () { #ifdef __LP64__ struct gdbarch *gdbarch = get_frame_arch (get_current_frame ()); /* Is the inferior 32-bit? If so, use the 32-bit siginfo size. */ if (gdbarch_long_bit (gdbarch) == 32) return sizeof (struct siginfo32); #endif return sizeof (siginfo_t); } /* Convert a native 64-bit siginfo object to a 32-bit object. Note that FreeBSD doesn't support writing to $_siginfo, so this only needs to convert one way. */ static void fbsd_convert_siginfo (siginfo_t *si) { #ifdef __LP64__ struct gdbarch *gdbarch = get_frame_arch (get_current_frame ()); /* Is the inferior 32-bit? If not, nothing to do. */ if (gdbarch_long_bit (gdbarch) != 32) return; struct siginfo32 si32; si32.si_signo = si->si_signo; si32.si_errno = si->si_errno; si32.si_code = si->si_code; si32.si_pid = si->si_pid; si32.si_uid = si->si_uid; si32.si_status = si->si_status; si32.si_addr = (uintptr_t) si->si_addr; /* If sival_ptr is being used instead of sival_int on a big-endian platform, then sival_int will be zero since it holds the upper 32-bits of the pointer value. */ #if _BYTE_ORDER == _BIG_ENDIAN if (si->si_value.sival_int == 0) si32.si_value.sival_ptr = (uintptr_t) si->si_value.sival_ptr; else si32.si_value.sival_int = si->si_value.sival_int; #else si32.si_value.sival_int = si->si_value.sival_int; #endif /* Always copy the spare fields and then possibly overwrite them for signal-specific or code-specific fields. */ si32._reason.__spare__.__spare1__ = si->_reason.__spare__.__spare1__; for (int i = 0; i < 7; i++) si32._reason.__spare__.__spare2__[i] = si->_reason.__spare__.__spare2__[i]; switch (si->si_signo) { case SIGILL: case SIGFPE: case SIGSEGV: case SIGBUS: si32.si_trapno = si->si_trapno; break; } switch (si->si_code) { case SI_TIMER: si32.si_timerid = si->si_timerid; si32.si_overrun = si->si_overrun; break; case SI_MESGQ: si32.si_mqd = si->si_mqd; break; } memcpy(si, &si32, sizeof (si32)); #endif } #endif /* Implement the "to_xfer_partial target_ops" method. */ static enum target_xfer_status fbsd_xfer_partial (struct target_ops *ops, enum target_object object, const char *annex, gdb_byte *readbuf, const gdb_byte *writebuf, ULONGEST offset, ULONGEST len, ULONGEST *xfered_len) { pid_t pid = ptid_get_pid (inferior_ptid); switch (object) { #ifdef PT_LWPINFO case TARGET_OBJECT_SIGNAL_INFO: { struct ptrace_lwpinfo pl; size_t siginfo_size; /* FreeBSD doesn't support writing to $_siginfo. */ if (writebuf != NULL) return TARGET_XFER_E_IO; if (inferior_ptid.lwp_p ()) pid = inferior_ptid.lwp (); siginfo_size = fbsd_siginfo_size (); if (offset > siginfo_size) return TARGET_XFER_E_IO; if (ptrace (PT_LWPINFO, pid, (PTRACE_TYPE_ARG3) &pl, sizeof (pl)) == -1) return TARGET_XFER_E_IO; if (!(pl.pl_flags & PL_FLAG_SI)) return TARGET_XFER_E_IO; fbsd_convert_siginfo (&pl.pl_siginfo); if (offset + len > siginfo_size) len = siginfo_size - offset; memcpy (readbuf, ((gdb_byte *) &pl.pl_siginfo) + offset, len); *xfered_len = len; return TARGET_XFER_OK; } #endif case TARGET_OBJECT_AUXV: { gdb::byte_vector buf_storage; gdb_byte *buf; size_t buflen; int mib[4]; if (writebuf != NULL) return TARGET_XFER_E_IO; mib[0] = CTL_KERN; mib[1] = KERN_PROC; mib[2] = KERN_PROC_AUXV; mib[3] = pid; if (offset == 0) { buf = readbuf; buflen = len; } else { buflen = offset + len; buf_storage.resize (buflen); buf = buf_storage.data (); } if (sysctl (mib, 4, buf, &buflen, NULL, 0) == 0) { if (offset != 0) { if (buflen > offset) { buflen -= offset; memcpy (readbuf, buf + offset, buflen); } else buflen = 0; } *xfered_len = buflen; return (buflen == 0) ? TARGET_XFER_EOF : TARGET_XFER_OK; } return TARGET_XFER_E_IO; } default: return super_xfer_partial (ops, object, annex, readbuf, writebuf, offset, len, xfered_len); } } #endif #ifdef PT_LWPINFO static int debug_fbsd_lwp; static int debug_fbsd_nat; static void (*super_resume) (struct target_ops *, ptid_t, int, enum gdb_signal); static ptid_t (*super_wait) (struct target_ops *, ptid_t, struct target_waitstatus *, int); static void show_fbsd_lwp_debug (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { fprintf_filtered (file, _("Debugging of FreeBSD lwp module is %s.\n"), value); } static void show_fbsd_nat_debug (struct ui_file *file, int from_tty, struct cmd_list_element *c, const char *value) { fprintf_filtered (file, _("Debugging of FreeBSD native target is %s.\n"), value); } /* FreeBSD's first thread support was via a "reentrant" version of libc (libc_r) that first shipped in 2.2.7. This library multiplexed all of the threads in a process onto a single kernel thread. This library was supported via the bsd-uthread target. FreeBSD 5.1 introduced two new threading libraries that made use of multiple kernel threads. The first (libkse) scheduled M user threads onto N (<= M) kernel threads (LWPs). The second (libthr) bound each user thread to a dedicated kernel thread. libkse shipped as the default threading library (libpthread). FreeBSD 5.3 added a libthread_db to abstract the interface across the various thread libraries (libc_r, libkse, and libthr). FreeBSD 7.0 switched the default threading library from from libkse to libpthread and removed libc_r. FreeBSD 8.0 removed libkse and the in-kernel support for it. The only threading library supported by 8.0 and later is libthr which ties each user thread directly to an LWP. To simplify the implementation, this target only supports LWP-backed threads using ptrace directly rather than libthread_db. FreeBSD 11.0 introduced LWP event reporting via PT_LWP_EVENTS. */ /* Return true if PTID is still active in the inferior. */ static int fbsd_thread_alive (struct target_ops *ops, ptid_t ptid) { if (ptid_lwp_p (ptid)) { struct ptrace_lwpinfo pl; if (ptrace (PT_LWPINFO, ptid_get_lwp (ptid), (caddr_t) &pl, sizeof pl) == -1) return 0; #ifdef PL_FLAG_EXITED if (pl.pl_flags & PL_FLAG_EXITED) return 0; #endif } return 1; } /* Convert PTID to a string. Returns the string in a static buffer. */ static const char * fbsd_pid_to_str (struct target_ops *ops, ptid_t ptid) { lwpid_t lwp; lwp = ptid_get_lwp (ptid); if (lwp != 0) { static char buf[64]; int pid = ptid_get_pid (ptid); xsnprintf (buf, sizeof buf, "LWP %d of process %d", lwp, pid); return buf; } return normal_pid_to_str (ptid); } #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME /* Return the name assigned to a thread by an application. Returns the string in a static buffer. */ static const char * fbsd_thread_name (struct target_ops *self, struct thread_info *thr) { struct ptrace_lwpinfo pl; struct kinfo_proc kp; int pid = ptid_get_pid (thr->ptid); long lwp = ptid_get_lwp (thr->ptid); static char buf[sizeof pl.pl_tdname + 1]; /* Note that ptrace_lwpinfo returns the process command in pl_tdname if a name has not been set explicitly. Return a NULL name in that case. */ if (!fbsd_fetch_kinfo_proc (pid, &kp)) perror_with_name (_("Failed to fetch process information")); if (ptrace (PT_LWPINFO, lwp, (caddr_t) &pl, sizeof pl) == -1) perror_with_name (("ptrace")); if (strcmp (kp.ki_comm, pl.pl_tdname) == 0) return NULL; xsnprintf (buf, sizeof buf, "%s", pl.pl_tdname); return buf; } #endif /* Enable additional event reporting on new processes. To catch fork events, PTRACE_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. To catch LWP events, PTRACE_EVENTS is set on every traced process. This enables stops on the birth for new LWPs (excluding the "main" LWP) and the death of LWPs (excluding the last LWP in a process). Note that unlike fork events, the LWP that creates a new LWP does not report an event. */ static void fbsd_enable_proc_events (pid_t pid) { #ifdef PT_GET_EVENT_MASK int events; if (ptrace (PT_GET_EVENT_MASK, pid, (PTRACE_TYPE_ARG3)&events, sizeof (events)) == -1) perror_with_name (("ptrace")); events |= PTRACE_FORK | PTRACE_LWP; #ifdef PTRACE_VFORK events |= PTRACE_VFORK; #endif if (ptrace (PT_SET_EVENT_MASK, pid, (PTRACE_TYPE_ARG3)&events, sizeof (events)) == -1) perror_with_name (("ptrace")); #else #ifdef TDP_RFPPWAIT if (ptrace (PT_FOLLOW_FORK, pid, (PTRACE_TYPE_ARG3)0, 1) == -1) perror_with_name (("ptrace")); #endif #ifdef PT_LWP_EVENTS if (ptrace (PT_LWP_EVENTS, pid, (PTRACE_TYPE_ARG3)0, 1) == -1) perror_with_name (("ptrace")); #endif #endif } /* Add threads for any new LWPs in a process. When LWP events are used, this function is only used to detect existing threads when attaching to a process. On older systems, this function is called to discover new threads each time the thread list is updated. */ static void fbsd_add_threads (pid_t pid) { int i, nlwps; gdb_assert (!in_thread_list (pid_to_ptid (pid))); nlwps = ptrace (PT_GETNUMLWPS, pid, NULL, 0); if (nlwps == -1) perror_with_name (("ptrace")); gdb::unique_xmalloc_ptr lwps (XCNEWVEC (lwpid_t, nlwps)); nlwps = ptrace (PT_GETLWPLIST, pid, (caddr_t) lwps.get (), nlwps); if (nlwps == -1) perror_with_name (("ptrace")); for (i = 0; i < nlwps; i++) { ptid_t ptid = ptid_build (pid, lwps[i], 0); if (!in_thread_list (ptid)) { #ifdef PT_LWP_EVENTS struct ptrace_lwpinfo pl; /* Don't add exited threads. Note that this is only called when attaching to a multi-threaded process. */ if (ptrace (PT_LWPINFO, lwps[i], (caddr_t) &pl, sizeof pl) == -1) perror_with_name (("ptrace")); if (pl.pl_flags & PL_FLAG_EXITED) continue; #endif if (debug_fbsd_lwp) fprintf_unfiltered (gdb_stdlog, "FLWP: adding thread for LWP %u\n", lwps[i]); add_thread (ptid); } } } /* Implement the "to_update_thread_list" target_ops method. */ static void fbsd_update_thread_list (struct target_ops *ops) { #ifdef PT_LWP_EVENTS /* With support for thread events, threads are added/deleted from the list as events are reported, so just try deleting exited threads. */ delete_exited_threads (); #else prune_threads (); fbsd_add_threads (ptid_get_pid (inferior_ptid)); #endif } #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. */ static std::list 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 (ptid_t pid) { fbsd_pending_children.push_front (pid); } /* Check for a previously-recorded new child process event for PID. If one is found, remove it from the list and return the PTID. */ static ptid_t fbsd_is_child_pending (pid_t pid) { for (auto it = fbsd_pending_children.begin (); it != fbsd_pending_children.end (); it++) if (it->pid () == pid) { ptid_t ptid = *it; fbsd_pending_children.erase (it); return ptid; } return null_ptid; } #ifndef PTRACE_VFORK static std::forward_list fbsd_pending_vfork_done; /* Record a pending vfork done event. */ static void fbsd_add_vfork_done (ptid_t pid) { fbsd_pending_vfork_done.push_front (pid); } /* Check for a pending vfork done event for a specific PID. */ static int fbsd_is_vfork_done_pending (pid_t pid) { for (auto it = fbsd_pending_vfork_done.begin (); it != fbsd_pending_vfork_done.end (); it++) if (it->pid () == pid) return 1; return 0; } /* Check for a pending vfork done event. If one is found, remove it from the list and return the PTID. */ static ptid_t fbsd_next_vfork_done (void) { if (!fbsd_pending_vfork_done.empty ()) { ptid_t ptid = fbsd_pending_vfork_done.front (); fbsd_pending_vfork_done.pop_front (); return ptid; } return null_ptid; } #endif #endif /* Implement the "to_resume" target_ops method. */ static void fbsd_resume (struct target_ops *ops, ptid_t ptid, int step, enum gdb_signal signo) { #if defined(TDP_RFPPWAIT) && !defined(PTRACE_VFORK) pid_t pid; /* Don't PT_CONTINUE a process which has a pending vfork done event. */ if (ptid_equal (minus_one_ptid, ptid)) pid = ptid_get_pid (inferior_ptid); else pid = ptid_get_pid (ptid); if (fbsd_is_vfork_done_pending (pid)) return; #endif if (debug_fbsd_lwp) fprintf_unfiltered (gdb_stdlog, "FLWP: fbsd_resume for ptid (%d, %ld, %ld)\n", ptid_get_pid (ptid), ptid_get_lwp (ptid), ptid_get_tid (ptid)); if (ptid_lwp_p (ptid)) { /* If ptid is a specific LWP, suspend all other LWPs in the process. */ struct thread_info *tp; int request; ALL_NON_EXITED_THREADS (tp) { if (ptid_get_pid (tp->ptid) != ptid_get_pid (ptid)) continue; if (ptid_get_lwp (tp->ptid) == ptid_get_lwp (ptid)) request = PT_RESUME; else request = PT_SUSPEND; if (ptrace (request, ptid_get_lwp (tp->ptid), NULL, 0) == -1) perror_with_name (("ptrace")); } } else { /* If ptid is a wildcard, resume all matching threads (they won't run until the process is continued however). */ struct thread_info *tp; ALL_NON_EXITED_THREADS (tp) { if (!ptid_match (tp->ptid, ptid)) continue; if (ptrace (PT_RESUME, ptid_get_lwp (tp->ptid), NULL, 0) == -1) perror_with_name (("ptrace")); } ptid = inferior_ptid; } #if __FreeBSD_version < 1200052 /* When multiple threads within a process wish to report STOPPED events from wait(), the kernel picks one thread event as the thread event to report. The chosen thread event is retrieved via PT_LWPINFO by passing the process ID as the request pid. If multiple events are pending, then the subsequent wait() after resuming a process will report another STOPPED event after resuming the process to handle the next thread event and so on. A single thread event is cleared as a side effect of resuming the process with PT_CONTINUE, PT_STEP, etc. In older kernels, however, the request pid was used to select which thread's event was cleared rather than always clearing the event that was just reported. To avoid clearing the event of the wrong LWP, always pass the process ID instead of an LWP ID to PT_CONTINUE or PT_SYSCALL. In the case of stepping, the process ID cannot be used with PT_STEP since it would step the thread that reported an event which may not be the thread indicated by PTID. For stepping, use PT_SETSTEP to enable stepping on the desired thread before resuming the process via PT_CONTINUE instead of using PT_STEP. */ if (step) { if (ptrace (PT_SETSTEP, get_ptrace_pid (ptid), NULL, 0) == -1) perror_with_name (("ptrace")); step = 0; } ptid = ptid_t (ptid.pid ()); #endif super_resume (ops, ptid, step, signo); } /* 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) { #ifndef PTRACE_VFORK wptid = fbsd_next_vfork_done (); if (!ptid_equal (wptid, null_ptid)) { ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; return wptid; } #endif 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")); wptid = ptid_build (pid, pl.pl_lwpid, 0); if (debug_fbsd_nat) { fprintf_unfiltered (gdb_stdlog, "FNAT: stop for LWP %u event %d flags %#x\n", pl.pl_lwpid, pl.pl_event, pl.pl_flags); if (pl.pl_flags & PL_FLAG_SI) fprintf_unfiltered (gdb_stdlog, "FNAT: si_signo %u si_code %u\n", pl.pl_siginfo.si_signo, pl.pl_siginfo.si_code); } #ifdef PT_LWP_EVENTS if (pl.pl_flags & PL_FLAG_EXITED) { /* If GDB attaches to a multi-threaded process, exiting threads might be skipped during fbsd_post_attach that have not yet reported their PL_FLAG_EXITED event. Ignore EXITED events for an unknown LWP. */ if (in_thread_list (wptid)) { if (debug_fbsd_lwp) fprintf_unfiltered (gdb_stdlog, "FLWP: deleting thread for LWP %u\n", pl.pl_lwpid); if (print_thread_events) printf_unfiltered (_("[%s exited]\n"), target_pid_to_str (wptid)); delete_thread (wptid); } if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1) perror_with_name (("ptrace")); continue; } #endif /* Switch to an LWP PTID on the first stop in a new process. This is done after handling PL_FLAG_EXITED to avoid switching to an exited LWP. It is done before checking PL_FLAG_BORN in case the first stop reported after attaching to an existing process is a PL_FLAG_BORN event. */ if (in_thread_list (pid_to_ptid (pid))) { if (debug_fbsd_lwp) fprintf_unfiltered (gdb_stdlog, "FLWP: using LWP %u for first thread\n", pl.pl_lwpid); thread_change_ptid (pid_to_ptid (pid), wptid); } #ifdef PT_LWP_EVENTS if (pl.pl_flags & PL_FLAG_BORN) { /* If GDB attaches to a multi-threaded process, newborn threads might be added by fbsd_add_threads that have not yet reported their PL_FLAG_BORN event. Ignore BORN events for an already-known LWP. */ if (!in_thread_list (wptid)) { if (debug_fbsd_lwp) fprintf_unfiltered (gdb_stdlog, "FLWP: adding thread for LWP %u\n", pl.pl_lwpid); add_thread (wptid); } ourstatus->kind = TARGET_WAITKIND_SPURIOUS; return wptid; } #endif #ifdef TDP_RFPPWAIT if (pl.pl_flags & PL_FLAG_FORKED) { #ifndef PTRACE_VFORK struct kinfo_proc kp; #endif ptid_t child_ptid; pid_t child; child = pl.pl_child_pid; ourstatus->kind = TARGET_WAITKIND_FORKED; #ifdef PTRACE_VFORK if (pl.pl_flags & PL_FLAG_VFORKED) ourstatus->kind = TARGET_WAITKIND_VFORKED; #endif /* Make sure the other end of the fork is stopped too. */ child_ptid = fbsd_is_child_pending (child); if (ptid_equal (child_ptid, null_ptid)) { 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); child_ptid = ptid_build (child, pl.pl_lwpid, 0); } /* Enable additional events on the child process. */ fbsd_enable_proc_events (ptid_get_pid (child_ptid)); #ifndef PTRACE_VFORK /* For vfork, the child process will have the P_PPWAIT flag set. */ if (fbsd_fetch_kinfo_proc (child, &kp)) { if (kp.ki_flag & P_PPWAIT) ourstatus->kind = TARGET_WAITKIND_VFORKED; } else warning (_("Failed to fetch process information")); #endif ourstatus->value.related_pid = child_ptid; 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 (wptid); continue; } #ifdef PTRACE_VFORK if (pl.pl_flags & PL_FLAG_VFORK_DONE) { ourstatus->kind = TARGET_WAITKIND_VFORK_DONE; return wptid; } #endif #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 /* Note that PL_FLAG_SCE is set for any event reported while a thread is executing a system call in the kernel. In particular, signals that interrupt a sleep in a system call will report this flag as part of their event. Stops explicitly for system call entry and exit always use SIGTRAP, so only treat SIGTRAP events as system call entry/exit events. */ if (pl.pl_flags & (PL_FLAG_SCE | PL_FLAG_SCX) && ourstatus->value.sig == SIGTRAP) { #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE if (catch_syscall_enabled ()) { if (catching_syscall_number (pl.pl_syscall_code)) { if (pl.pl_flags & PL_FLAG_SCE) ourstatus->kind = TARGET_WAITKIND_SYSCALL_ENTRY; else ourstatus->kind = TARGET_WAITKIND_SYSCALL_RETURN; ourstatus->value.syscall_number = pl.pl_syscall_code; return wptid; } } #endif /* If the core isn't interested in this event, just continue the process explicitly and wait for another event. Note that PT_SYSCALL is "sticky" on FreeBSD and once system call stops are enabled on a process it stops for all system call entries and exits. */ if (ptrace (PT_CONTINUE, pid, (caddr_t) 1, 0) == -1) perror_with_name (("ptrace")); continue; } } 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 && detach_fork) { 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")); #ifndef PTRACE_VFORK if (tp->pending_follow.kind == TARGET_WAITKIND_VFORKED) { /* We can't insert breakpoints until the child process has finished with the shared memory region. The parent process doesn't wait for the child process to exit or exec until after it has been resumed from the ptrace stop to report the fork. Once it has been resumed it doesn't stop again before returning to userland, so there is no reliable way to wait on the parent. We can't stay attached to the child to wait for an exec or exit because it may invoke ptrace(PT_TRACE_ME) (e.g. if the parent process is a debugger forking a new child process). 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); /* Schedule a fake VFORK_DONE event to report on the next wait. */ fbsd_add_vfork_done (inferior_ptid); } #endif } 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; } #endif /* Implement the "to_post_startup_inferior" target_ops method. */ static void fbsd_post_startup_inferior (struct target_ops *self, ptid_t pid) { fbsd_enable_proc_events (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_proc_events (pid); fbsd_add_threads (pid); } #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 #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE static int fbsd_set_syscall_catchpoint (struct target_ops *self, int pid, bool needed, int any_count, gdb::array_view syscall_counts) { /* Ignore the arguments. inf-ptrace.c will use PT_SYSCALL which will catch all system call entries and exits. The system calls are filtered by GDB rather than the kernel. */ 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; t->to_info_proc = fbsd_info_proc; #ifdef KERN_PROC_AUXV super_xfer_partial = t->to_xfer_partial; t->to_xfer_partial = fbsd_xfer_partial; #endif #ifdef PT_LWPINFO t->to_thread_alive = fbsd_thread_alive; t->to_pid_to_str = fbsd_pid_to_str; #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_TDNAME t->to_thread_name = fbsd_thread_name; #endif t->to_update_thread_list = fbsd_update_thread_list; t->to_has_thread_control = tc_schedlock; super_resume = t->to_resume; t->to_resume = fbsd_resume; super_wait = t->to_wait; t->to_wait = fbsd_wait; t->to_post_startup_inferior = fbsd_post_startup_inferior; t->to_post_attach = fbsd_post_attach; #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; #endif #ifdef PL_FLAG_EXEC t->to_insert_exec_catchpoint = fbsd_insert_exec_catchpoint; t->to_remove_exec_catchpoint = fbsd_remove_exec_catchpoint; #endif #ifdef HAVE_STRUCT_PTRACE_LWPINFO_PL_SYSCALL_CODE t->to_set_syscall_catchpoint = fbsd_set_syscall_catchpoint; #endif #endif add_target (t); } void _initialize_fbsd_nat (void) { #ifdef PT_LWPINFO add_setshow_boolean_cmd ("fbsd-lwp", class_maintenance, &debug_fbsd_lwp, _("\ Set debugging of FreeBSD lwp module."), _("\ Show debugging of FreeBSD lwp module."), _("\ Enables printf debugging output."), NULL, &show_fbsd_lwp_debug, &setdebuglist, &showdebuglist); add_setshow_boolean_cmd ("fbsd-nat", class_maintenance, &debug_fbsd_nat, _("\ Set debugging of FreeBSD native target."), _("\ Show debugging of FreeBSD native target."), _("\ Enables printf debugging output."), NULL, &show_fbsd_nat_debug, &setdebuglist, &showdebuglist); #endif }