/* Native-dependent code for NetBSD.
Copyright (C) 2006-2022 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 "netbsd-nat.h"
#include "nat/netbsd-nat.h"
#include "gdbthread.h"
#include "netbsd-tdep.h"
#include "inferior.h"
#include "gdbarch.h"
#include "gdbsupport/buildargv.h"
#include <sys/types.h>
#include <sys/ptrace.h>
#include <sys/sysctl.h>
#include <sys/wait.h>
/* Return the name of a file that can be opened to get the symbols for
the child process identified by PID. */
const char *
nbsd_nat_target::pid_to_exec_file (int pid)
{
return netbsd_nat::pid_to_exec_file (pid);
}
/* Return the current directory for the process identified by PID. */
static std::string
nbsd_pid_to_cwd (int pid)
{
char buf[PATH_MAX];
size_t buflen;
int mib[4] = {CTL_KERN, KERN_PROC_ARGS, pid, KERN_PROC_CWD};
buflen = sizeof (buf);
if (sysctl (mib, ARRAY_SIZE (mib), buf, &buflen, NULL, 0))
return "";
return buf;
}
/* Return the kinfo_proc2 structure for the process identified by PID. */
static bool
nbsd_pid_to_kinfo_proc2 (pid_t pid, struct kinfo_proc2 *kp)
{
gdb_assert (kp != nullptr);
size_t size = sizeof (*kp);
int mib[6] = {CTL_KERN, KERN_PROC2, KERN_PROC_PID, pid,
static_cast<int> (size), 1};
return !sysctl (mib, ARRAY_SIZE (mib), kp, &size, NULL, 0);
}
/* Return the command line for the process identified by PID. */
static gdb::unique_xmalloc_ptr<char[]>
nbsd_pid_to_cmdline (int pid)
{
int mib[4] = {CTL_KERN, KERN_PROC_ARGS, pid, KERN_PROC_ARGV};
size_t size = 0;
if (::sysctl (mib, ARRAY_SIZE (mib), NULL, &size, NULL, 0) == -1 || size == 0)
return nullptr;
gdb::unique_xmalloc_ptr<char[]> args (XNEWVAR (char, size));
if (::sysctl (mib, ARRAY_SIZE (mib), args.get (), &size, NULL, 0) == -1
|| size == 0)
return nullptr;
/* Arguments are returned as a flattened string with NUL separators.
Join the arguments with spaces to form a single string. */
for (size_t i = 0; i < size - 1; i++)
if (args[i] == '\0')
args[i] = ' ';
args[size - 1] = '\0';
return args;
}
/* Return true if PTID is still active in the inferior. */
bool
nbsd_nat_target::thread_alive (ptid_t ptid)
{
return netbsd_nat::thread_alive (ptid);
}
/* Return the name assigned to a thread by an application. Returns
the string in a static buffer. */
const char *
nbsd_nat_target::thread_name (struct thread_info *thr)
{
ptid_t ptid = thr->ptid;
return netbsd_nat::thread_name (ptid);
}
/* Implement the "post_attach" target_ops method. */
static void
nbsd_add_threads (nbsd_nat_target *target, pid_t pid)
{
auto fn
= [&target] (ptid_t ptid)
{
if (!in_thread_list (target, ptid))
{
if (inferior_ptid.lwp () == 0)
thread_change_ptid (target, inferior_ptid, ptid);
else
add_thread (target, ptid);
}
};
netbsd_nat::for_each_thread (pid, fn);
}
/* Implement the virtual inf_ptrace_target::post_startup_inferior method. */
void
nbsd_nat_target::post_startup_inferior (ptid_t ptid)
{
netbsd_nat::enable_proc_events (ptid.pid ());
}
/* Implement the "post_attach" target_ops method. */
void
nbsd_nat_target::post_attach (int pid)
{
netbsd_nat::enable_proc_events (pid);
nbsd_add_threads (this, pid);
}
/* Implement the "update_thread_list" target_ops method. */
void
nbsd_nat_target::update_thread_list ()
{
delete_exited_threads ();
}
/* Convert PTID to a string. */
std::string
nbsd_nat_target::pid_to_str (ptid_t ptid)
{
int lwp = ptid.lwp ();
if (lwp != 0)
{
pid_t pid = ptid.pid ();
return string_printf ("LWP %d of process %d", lwp, pid);
}
return normal_pid_to_str (ptid);
}
/* Retrieve all the memory regions in the specified process. */
static gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]>
nbsd_kinfo_get_vmmap (pid_t pid, size_t *size)
{
int mib[5] = {CTL_VM, VM_PROC, VM_PROC_MAP, pid,
sizeof (struct kinfo_vmentry)};
size_t length = 0;
if (sysctl (mib, ARRAY_SIZE (mib), NULL, &length, NULL, 0))
{
*size = 0;
return NULL;
}
/* Prereserve more space. The length argument is volatile and can change
between the sysctl(3) calls as this function can be called against a
running process. */
length = length * 5 / 3;
gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> kiv
(XNEWVAR (kinfo_vmentry, length));
if (sysctl (mib, ARRAY_SIZE (mib), kiv.get (), &length, NULL, 0))
{
*size = 0;
return NULL;
}
*size = length / sizeof (struct kinfo_vmentry);
return kiv;
}
/* 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. */
int
nbsd_nat_target::find_memory_regions (find_memory_region_ftype func,
void *data)
{
pid_t pid = inferior_ptid.pid ();
size_t nitems;
gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> vmentl
= nbsd_kinfo_get_vmmap (pid, &nitems);
if (vmentl == NULL)
perror_with_name (_("Couldn't fetch VM map entries"));
for (size_t i = 0; i < nitems; i++)
{
struct kinfo_vmentry *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. */
switch (kve->kve_type)
{
case KVME_TYPE_VNODE:
case KVME_TYPE_ANON:
case KVME_TYPE_SUBMAP:
case KVME_TYPE_OBJECT:
break;
default:
continue;
}
size_t size = kve->kve_end - kve->kve_start;
if (info_verbose)
{
gdb_printf ("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, false, data);
}
return 0;
}
/* Implement the "info_proc" target_ops method. */
bool
nbsd_nat_target::info_proc (const char *args, enum info_proc_what what)
{
pid_t pid;
bool do_cmdline = false;
bool do_cwd = false;
bool do_exe = false;
bool do_mappings = false;
bool do_status = false;
switch (what)
{
case IP_MINIMAL:
do_cmdline = true;
do_cwd = true;
do_exe = true;
break;
case IP_STAT:
case IP_STATUS:
do_status = true;
break;
case IP_MAPPINGS:
do_mappings = 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;
do_mappings = true;
do_status = true;
break;
default:
error (_("Not supported on this target."));
}
gdb_argv built_argv (args);
if (built_argv.count () == 0)
{
pid = inferior_ptid.pid ();
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."));
gdb_printf (_("process %d\n"), pid);
if (do_cmdline)
{
gdb::unique_xmalloc_ptr<char[]> cmdline = nbsd_pid_to_cmdline (pid);
if (cmdline != nullptr)
gdb_printf ("cmdline = '%s'\n", cmdline.get ());
else
warning (_("unable to fetch command line"));
}
if (do_cwd)
{
std::string cwd = nbsd_pid_to_cwd (pid);
if (cwd != "")
gdb_printf ("cwd = '%s'\n", cwd.c_str ());
else
warning (_("unable to fetch current working directory"));
}
if (do_exe)
{
const char *exe = pid_to_exec_file (pid);
if (exe != nullptr)
gdb_printf ("exe = '%s'\n", exe);
else
warning (_("unable to fetch executable path name"));
}
if (do_mappings)
{
size_t nvment;
gdb::unique_xmalloc_ptr<struct kinfo_vmentry[]> vmentl
= nbsd_kinfo_get_vmmap (pid, &nvment);
if (vmentl != nullptr)
{
int addr_bit = TARGET_CHAR_BIT * sizeof (void *);
nbsd_info_proc_mappings_header (addr_bit);
struct kinfo_vmentry *kve = vmentl.get ();
for (int i = 0; i < nvment; i++, kve++)
nbsd_info_proc_mappings_entry (addr_bit, kve->kve_start,
kve->kve_end, kve->kve_offset,
kve->kve_flags, kve->kve_protection,
kve->kve_path);
}
else
warning (_("unable to fetch virtual memory map"));
}
if (do_status)
{
struct kinfo_proc2 kp;
if (!nbsd_pid_to_kinfo_proc2 (pid, &kp))
warning (_("Failed to fetch process information"));
else
{
auto process_status
= [] (int8_t stat)
{
switch (stat)
{
case SIDL:
return "IDL";
case SACTIVE:
return "ACTIVE";
case SDYING:
return "DYING";
case SSTOP:
return "STOP";
case SZOMB:
return "ZOMB";
case SDEAD:
return "DEAD";
default:
return "? (unknown)";
}
};
gdb_printf ("Name: %s\n", kp.p_comm);
gdb_printf ("State: %s\n", process_status(kp.p_realstat));
gdb_printf ("Parent process: %" PRId32 "\n", kp.p_ppid);
gdb_printf ("Process group: %" PRId32 "\n", kp.p__pgid);
gdb_printf ("Session id: %" PRId32 "\n", kp.p_sid);
gdb_printf ("TTY: %" PRId32 "\n", kp.p_tdev);
gdb_printf ("TTY owner process group: %" PRId32 "\n", kp.p_tpgid);
gdb_printf ("User IDs (real, effective, saved): "
"%" PRIu32 " %" PRIu32 " %" PRIu32 "\n",
kp.p_ruid, kp.p_uid, kp.p_svuid);
gdb_printf ("Group IDs (real, effective, saved): "
"%" PRIu32 " %" PRIu32 " %" PRIu32 "\n",
kp.p_rgid, kp.p_gid, kp.p_svgid);
gdb_printf ("Groups:");
for (int i = 0; i < kp.p_ngroups; i++)
gdb_printf (" %" PRIu32, kp.p_groups[i]);
gdb_printf ("\n");
gdb_printf ("Minor faults (no memory page): %" PRIu64 "\n",
kp.p_uru_minflt);
gdb_printf ("Major faults (memory page faults): %" PRIu64 "\n",
kp.p_uru_majflt);
gdb_printf ("utime: %" PRIu32 ".%06" PRIu32 "\n",
kp.p_uutime_sec, kp.p_uutime_usec);
gdb_printf ("stime: %" PRIu32 ".%06" PRIu32 "\n",
kp.p_ustime_sec, kp.p_ustime_usec);
gdb_printf ("utime+stime, children: %" PRIu32 ".%06" PRIu32 "\n",
kp.p_uctime_sec, kp.p_uctime_usec);
gdb_printf ("'nice' value: %" PRIu8 "\n", kp.p_nice);
gdb_printf ("Start time: %" PRIu32 ".%06" PRIu32 "\n",
kp.p_ustart_sec, kp.p_ustart_usec);
int pgtok = getpagesize () / 1024;
gdb_printf ("Data size: %" PRIuMAX " kB\n",
(uintmax_t) kp.p_vm_dsize * pgtok);
gdb_printf ("Stack size: %" PRIuMAX " kB\n",
(uintmax_t) kp.p_vm_ssize * pgtok);
gdb_printf ("Text size: %" PRIuMAX " kB\n",
(uintmax_t) kp.p_vm_tsize * pgtok);
gdb_printf ("Resident set size: %" PRIuMAX " kB\n",
(uintmax_t) kp.p_vm_rssize * pgtok);
gdb_printf ("Maximum RSS: %" PRIu64 " kB\n", kp.p_uru_maxrss);
gdb_printf ("Pending Signals:");
for (size_t i = 0; i < ARRAY_SIZE (kp.p_siglist.__bits); i++)
gdb_printf (" %08" PRIx32, kp.p_siglist.__bits[i]);
gdb_printf ("\n");
gdb_printf ("Ignored Signals:");
for (size_t i = 0; i < ARRAY_SIZE (kp.p_sigignore.__bits); i++)
gdb_printf (" %08" PRIx32, kp.p_sigignore.__bits[i]);
gdb_printf ("\n");
gdb_printf ("Caught Signals:");
for (size_t i = 0; i < ARRAY_SIZE (kp.p_sigcatch.__bits); i++)
gdb_printf (" %08" PRIx32, kp.p_sigcatch.__bits[i]);
gdb_printf ("\n");
}
}
return true;
}
/* Resume execution of a specified PTID, that points to a process or a thread
within a process. If one thread is specified, all other threads are
suspended. If STEP is nonzero, single-step it. If SIGNAL is nonzero,
give it that signal. */
static void
nbsd_resume(nbsd_nat_target *target, ptid_t ptid, int step,
enum gdb_signal signal)
{
int request;
gdb_assert (minus_one_ptid != ptid);
if (ptid.lwp_p ())
{
/* If ptid is a specific LWP, suspend all other LWPs in the process. */
inferior *inf = find_inferior_ptid (target, ptid);
for (thread_info *tp : inf->non_exited_threads ())
{
if (tp->ptid.lwp () == ptid.lwp ())
request = PT_RESUME;
else
request = PT_SUSPEND;
if (ptrace (request, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -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). */
for (thread_info *tp : all_non_exited_threads (target, ptid))
if (ptrace (PT_RESUME, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
}
if (step)
{
for (thread_info *tp : all_non_exited_threads (target, ptid))
if (ptrace (PT_SETSTEP, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
}
else
{
for (thread_info *tp : all_non_exited_threads (target, ptid))
if (ptrace (PT_CLEARSTEP, tp->ptid.pid (), NULL, tp->ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
}
if (catch_syscall_enabled () > 0)
request = PT_SYSCALL;
else
request = PT_CONTINUE;
/* An address of (void *)1 tells ptrace to continue from
where it was. If GDB wanted it to start some other way, we have
already written a new program counter value to the child. */
if (ptrace (request, ptid.pid (), (void *)1, gdb_signal_to_host (signal)) == -1)
perror_with_name (("ptrace"));
}
/* Resume execution of thread PTID, or all threads of all inferiors
if PTID is -1. If STEP is nonzero, single-step it. If SIGNAL is nonzero,
give it that signal. */
void
nbsd_nat_target::resume (ptid_t ptid, int step, enum gdb_signal signal)
{
if (minus_one_ptid != ptid)
nbsd_resume (this, ptid, step, signal);
else
{
for (inferior *inf : all_non_exited_inferiors (this))
nbsd_resume (this, ptid_t (inf->pid, 0, 0), step, signal);
}
}
/* Implement a safe wrapper around waitpid(). */
static pid_t
nbsd_wait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags options)
{
pid_t pid;
int status;
set_sigint_trap ();
do
{
/* The common code passes WNOHANG that leads to crashes, overwrite it. */
pid = waitpid (ptid.pid (), &status, 0);
}
while (pid == -1 && errno == EINTR);
clear_sigint_trap ();
if (pid == -1)
perror_with_name (_("Child process unexpectedly missing"));
*ourstatus = host_status_to_waitstatus (status);
return pid;
}
/* 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. */
ptid_t
nbsd_nat_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags target_options)
{
pid_t pid = nbsd_wait (ptid, ourstatus, target_options);
ptid_t wptid = ptid_t (pid);
/* If the child stopped, keep investigating its status. */
if (ourstatus->kind () != TARGET_WAITKIND_STOPPED)
return wptid;
/* Extract the event and thread that received a signal. */
ptrace_siginfo_t psi;
if (ptrace (PT_GET_SIGINFO, pid, &psi, sizeof (psi)) == -1)
perror_with_name (("ptrace"));
/* Pick child's siginfo_t. */
siginfo_t *si = &psi.psi_siginfo;
int lwp = psi.psi_lwpid;
int signo = si->si_signo;
const int code = si->si_code;
/* Construct PTID with a specified thread that received the event.
If a signal was targeted to the whole process, lwp is 0. */
wptid = ptid_t (pid, lwp, 0);
/* Bail out on non-debugger oriented signals.. */
if (signo != SIGTRAP)
return wptid;
/* Stop examining non-debugger oriented SIGTRAP codes. */
if (code <= SI_USER || code == SI_NOINFO)
return wptid;
/* Process state for threading events */
ptrace_state_t pst = {};
if (code == TRAP_LWP)
{
if (ptrace (PT_GET_PROCESS_STATE, pid, &pst, sizeof (pst)) == -1)
perror_with_name (("ptrace"));
}
if (code == TRAP_LWP && pst.pe_report_event == PTRACE_LWP_EXIT)
{
/* If GDB attaches to a multi-threaded process, exiting
threads might be skipped during post_attach that
have not yet reported their PTRACE_LWP_EXIT event.
Ignore exited events for an unknown LWP. */
thread_info *thr = find_thread_ptid (this, wptid);
if (thr == nullptr)
ourstatus->set_spurious ();
else
{
/* NetBSD does not store an LWP exit status. */
ourstatus->set_thread_exited (0);
if (print_thread_events)
gdb_printf (_("[%s exited]\n"),
target_pid_to_str (wptid).c_str ());
delete_thread (thr);
}
/* The GDB core expects that the rest of the threads are running. */
if (ptrace (PT_CONTINUE, pid, (void *) 1, 0) == -1)
perror_with_name (("ptrace"));
return wptid;
}
if (in_thread_list (this, ptid_t (pid)))
thread_change_ptid (this, ptid_t (pid), wptid);
if (code == TRAP_LWP && pst.pe_report_event == PTRACE_LWP_CREATE)
{
/* If GDB attaches to a multi-threaded process, newborn
threads might be added by nbsd_add_threads that have
not yet reported their PTRACE_LWP_CREATE event. Ignore
born events for an already-known LWP. */
if (in_thread_list (this, wptid))
ourstatus->set_spurious ();
else
{
add_thread (this, wptid);
ourstatus->set_thread_created ();
}
return wptid;
}
if (code == TRAP_EXEC)
{
ourstatus->set_execd (make_unique_xstrdup (pid_to_exec_file (pid)));
return wptid;
}
if (code == TRAP_TRACE)
{
/* Unhandled at this level. */
return wptid;
}
if (code == TRAP_SCE || code == TRAP_SCX)
{
int sysnum = si->si_sysnum;
if (!catch_syscall_enabled () || !catching_syscall_number (sysnum))
{
/* If the core isn't interested in this event, ignore it. */
ourstatus->set_spurious ();
return wptid;
}
if (code == TRAP_SCE)
ourstatus->set_syscall_entry (sysnum);
else
ourstatus->set_syscall_return (sysnum);
return wptid;
}
if (code == TRAP_BRKPT)
{
/* Unhandled at this level. */
return wptid;
}
/* Unclassified SIGTRAP event. */
ourstatus->set_spurious ();
return wptid;
}
/* Implement the "insert_exec_catchpoint" target_ops method. */
int
nbsd_nat_target::insert_exec_catchpoint (int pid)
{
/* Nothing to do. */
return 0;
}
/* Implement the "remove_exec_catchpoint" target_ops method. */
int
nbsd_nat_target::remove_exec_catchpoint (int pid)
{
/* Nothing to do. */
return 0;
}
/* Implement the "set_syscall_catchpoint" target_ops method. */
int
nbsd_nat_target::set_syscall_catchpoint (int pid, bool needed,
int any_count,
gdb::array_view<const int> 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;
}
/* Implement the "supports_multi_process" target_ops method. */
bool
nbsd_nat_target::supports_multi_process ()
{
return true;
}
/* Implement the "xfer_partial" target_ops method. */
enum target_xfer_status
nbsd_nat_target::xfer_partial (enum target_object object,
const char *annex, gdb_byte *readbuf,
const gdb_byte *writebuf,
ULONGEST offset, ULONGEST len,
ULONGEST *xfered_len)
{
pid_t pid = inferior_ptid.pid ();
switch (object)
{
case TARGET_OBJECT_SIGNAL_INFO:
{
len = netbsd_nat::qxfer_siginfo(pid, annex, readbuf, writebuf, offset,
len);
if (len == -1)
return TARGET_XFER_E_IO;
*xfered_len = len;
return TARGET_XFER_OK;
}
case TARGET_OBJECT_MEMORY:
{
size_t xfered;
int res;
if (writebuf != nullptr)
res = netbsd_nat::write_memory (pid, writebuf, offset, len, &xfered);
else
res = netbsd_nat::read_memory (pid, readbuf, offset, len, &xfered);
if (res != 0)
{
if (res == EACCES)
gdb_printf (gdb_stderr, "Cannot %s process at %s (%s). "
"Is PaX MPROTECT active? See security(7), "
"sysctl(7), paxctl(8)\n",
(writebuf ? "write to" : "read from"),
pulongest (offset), safe_strerror (errno));
return TARGET_XFER_E_IO;
}
if (xfered == 0)
return TARGET_XFER_EOF;
*xfered_len = (ULONGEST) xfered;
return TARGET_XFER_OK;
}
default:
return inf_ptrace_target::xfer_partial (object, annex,
readbuf, writebuf, offset,
len, xfered_len);
}
}
/* Implement the "supports_dumpcore" target_ops method. */
bool
nbsd_nat_target::supports_dumpcore ()
{
return true;
}
/* Implement the "dumpcore" target_ops method. */
void
nbsd_nat_target::dumpcore (const char *filename)
{
pid_t pid = inferior_ptid.pid ();
if (ptrace (PT_DUMPCORE, pid, const_cast<char *>(filename),
strlen (filename)) == -1)
perror_with_name (("ptrace"));
}