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netbsd-low.cc
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/* Copyright (C) 2020-2024 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 "target.h"
#include "netbsd-low.h"
#include "nat/netbsd-nat.h"
#include <sys/param.h>
#include <sys/types.h>
#include <sys/ptrace.h>
#include <sys/sysctl.h>
#include <limits.h>
#include <unistd.h>
#include <signal.h>
#include <elf.h>
#include <type_traits>
#include "gdbsupport/eintr.h"
#include "gdbsupport/gdb_wait.h"
#include "gdbsupport/filestuff.h"
#include "gdbsupport/common-inferior.h"
#include "nat/fork-inferior.h"
#include "hostio.h"
int using_threads = 1;
/* Callback used by fork_inferior to start tracing the inferior. */
static void
netbsd_ptrace_fun ()
{
/* Switch child to its own process group so that signals won't
directly affect GDBserver. */
if (setpgid (0, 0) < 0)
trace_start_error_with_name (("setpgid"));
if (ptrace (PT_TRACE_ME, 0, nullptr, 0) < 0)
trace_start_error_with_name (("ptrace"));
/* If GDBserver is connected to gdb via stdio, redirect the inferior's
stdout to stderr so that inferior i/o doesn't corrupt the connection.
Also, redirect stdin to /dev/null. */
if (remote_connection_is_stdio ())
{
if (close (0) < 0)
trace_start_error_with_name (("close"));
if (open ("/dev/null", O_RDONLY) < 0)
trace_start_error_with_name (("open"));
if (dup2 (2, 1) < 0)
trace_start_error_with_name (("dup2"));
if (write (2, "stdin/stdout redirected\n",
sizeof ("stdin/stdout redirected\n") - 1) < 0)
{
/* Errors ignored. */
}
}
}
/* Implement the create_inferior method of the target_ops vector. */
int
netbsd_process_target::create_inferior (const char *program,
const std::string &program_args)
{
pid_t pid = fork_inferior (program, program_args.c_str (),
get_environ ()->envp (), netbsd_ptrace_fun,
nullptr, nullptr, nullptr, nullptr);
add_process (pid, 0);
post_fork_inferior (pid, program);
return pid;
}
/* Implement the post_create_inferior target_ops method. */
void
netbsd_process_target::post_create_inferior ()
{
pid_t pid = current_process ()->pid;
netbsd_nat::enable_proc_events (pid);
low_arch_setup ();
}
/* Implement the attach target_ops method. */
int
netbsd_process_target::attach (unsigned long pid)
{
/* Unimplemented. */
return -1;
}
/* Returns true if GDB is interested in any child syscalls. */
static bool
gdb_catching_syscalls_p (pid_t pid)
{
struct process_info *proc = find_process_pid (pid);
return !proc->syscalls_to_catch.empty ();
}
/* Implement the resume target_ops method. */
void
netbsd_process_target::resume (struct thread_resume *resume_info, size_t n)
{
ptid_t resume_ptid = resume_info[0].thread;
const int signal = resume_info[0].sig;
const bool step = resume_info[0].kind == resume_step;
if (resume_ptid == minus_one_ptid)
resume_ptid = current_thread->id;
const pid_t pid = resume_ptid.pid ();
const lwpid_t lwp = resume_ptid.lwp ();
regcache_invalidate_pid (pid);
auto fn
= [&] (ptid_t ptid)
{
if (step)
{
if (ptid.lwp () == lwp || n != 1)
{
if (ptrace (PT_SETSTEP, pid, NULL, ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
if (ptrace (PT_RESUME, pid, NULL, ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
}
else
{
if (ptrace (PT_CLEARSTEP, pid, NULL, ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
if (ptrace (PT_SUSPEND, pid, NULL, ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
}
}
else
{
if (ptrace (PT_CLEARSTEP, pid, NULL, ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
if (ptrace (PT_RESUME, pid, NULL, ptid.lwp ()) == -1)
perror_with_name (("ptrace"));
}
};
netbsd_nat::for_each_thread (pid, fn);
int request = gdb_catching_syscalls_p (pid) ? PT_CONTINUE : PT_SYSCALL;
errno = 0;
ptrace (request, pid, (void *)1, signal);
if (errno)
perror_with_name (("ptrace"));
}
/* Returns true if GDB is interested in the reported SYSNO syscall. */
static bool
netbsd_catch_this_syscall (int sysno)
{
struct process_info *proc = current_process ();
if (proc->syscalls_to_catch.empty ())
return false;
if (proc->syscalls_to_catch[0] == ANY_SYSCALL)
return true;
for (int iter : proc->syscalls_to_catch)
if (iter == sysno)
return true;
return false;
}
/* Helper function for child_wait and the derivatives of child_wait.
HOSTSTATUS is the waitstatus from wait() or the equivalent; store our
translation of that in OURSTATUS. */
static void
netbsd_store_waitstatus (struct target_waitstatus *ourstatus, int hoststatus)
{
if (WIFEXITED (hoststatus))
ourstatus->set_exited (WEXITSTATUS (hoststatus));
else if (!WIFSTOPPED (hoststatus))
ourstatus->set_signalled (gdb_signal_from_host (WTERMSIG (hoststatus)));
else
ourstatus->set_stopped (gdb_signal_from_host (WSTOPSIG (hoststatus)));
}
/* Implement a safe wrapper around waitpid(). */
static pid_t
netbsd_waitpid (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags target_options)
{
int status;
int options = (target_options & TARGET_WNOHANG) ? WNOHANG : 0;
pid_t pid
= gdb::waitpid (ptid.pid (), &status, options);
if (pid == -1)
perror_with_name (_("Child process unexpectedly missing"));
netbsd_store_waitstatus (ourstatus, status);
return pid;
}
/* Implement the wait target_ops method.
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
netbsd_wait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags target_options)
{
pid_t pid = netbsd_waitpid (ptid, ourstatus, target_options);
ptid_t wptid = ptid_t (pid);
if (pid == 0)
{
gdb_assert (target_options & TARGET_WNOHANG);
ourstatus->set_ignore ();
return null_ptid;
}
gdb_assert (pid != -1);
/* 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;
lwpid_t 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 (wptid);
if (thr == nullptr)
ourstatus->set_spurious ();
else
{
/* NetBSD does not store an LWP exit status. */
ourstatus->set_thread_exited (0);
thr->process ()->remove_thread (thr);
}
return wptid;
}
if (find_thread_ptid (ptid_t (pid)))
switch_to_thread (find_thread_ptid (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 (find_thread_ptid (wptid))
ourstatus->set_spurious ();
else
{
find_process_pid (wptid.pid ())->add_thread (wptid, nullptr);
ourstatus->set_thread_created ();
}
return wptid;
}
if (code == TRAP_EXEC)
{
ourstatus->set_execd
(make_unique_xstrdup (netbsd_nat::pid_to_exec_file (pid)));
return wptid;
}
if (code == TRAP_TRACE)
return wptid;
if (code == TRAP_SCE || code == TRAP_SCX)
{
int sysnum = si->si_sysnum;
if (!netbsd_catch_this_syscall(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)
{
#ifdef PTRACE_BREAKPOINT_ADJ
CORE_ADDR pc;
struct reg r;
ptrace (PT_GETREGS, pid, &r, psi.psi_lwpid);
pc = PTRACE_REG_PC (&r);
PTRACE_REG_SET_PC (&r, pc - PTRACE_BREAKPOINT_ADJ);
ptrace (PT_SETREGS, pid, &r, psi.psi_lwpid);
#endif
return wptid;
}
/* Unclassified SIGTRAP event. */
ourstatus->set_spurious ();
return wptid;
}
/* Implement the wait target_ops method. */
ptid_t
netbsd_process_target::wait (ptid_t ptid, struct target_waitstatus *ourstatus,
target_wait_flags target_options)
{
while (true)
{
ptid_t wptid = netbsd_wait (ptid, ourstatus, target_options);
/* Register thread in the gdbcore if a thread was not reported earlier.
This is required after ::create_inferior, when the gdbcore does not
know about the first internal thread.
This may also happen on attach, when an event is registered on a thread
that was not fully initialized during the attach stage. */
if (wptid.lwp () != 0 && !find_thread_ptid (wptid)
&& ourstatus->kind () != TARGET_WAITKIND_THREAD_EXITED)
find_process_pid (wptid.pid ())->add_thread (wptid, nullptr);
switch (ourstatus->kind ())
{
case TARGET_WAITKIND_EXITED:
case TARGET_WAITKIND_STOPPED:
case TARGET_WAITKIND_SIGNALLED:
case TARGET_WAITKIND_FORKED:
case TARGET_WAITKIND_VFORKED:
case TARGET_WAITKIND_EXECD:
case TARGET_WAITKIND_VFORK_DONE:
case TARGET_WAITKIND_SYSCALL_ENTRY:
case TARGET_WAITKIND_SYSCALL_RETURN:
/* Pass the result to the generic code. */
return wptid;
case TARGET_WAITKIND_THREAD_CREATED:
case TARGET_WAITKIND_THREAD_EXITED:
/* The core needlessly stops on these events. */
[[fallthrough]];
case TARGET_WAITKIND_SPURIOUS:
/* Spurious events are unhandled by the gdbserver core. */
if (ptrace (PT_CONTINUE, current_process ()->pid, (void *) 1, 0)
== -1)
perror_with_name (("ptrace"));
break;
default:
error (("Unknown stopped status"));
}
}
}
/* Implement the kill target_ops method. */
int
netbsd_process_target::kill (process_info *process)
{
pid_t pid = process->pid;
if (ptrace (PT_KILL, pid, nullptr, 0) == -1)
return -1;
int status;
if (gdb::waitpid (pid, &status, 0) == -1)
return -1;
mourn (process);
return 0;
}
/* Implement the detach target_ops method. */
int
netbsd_process_target::detach (process_info *process)
{
pid_t pid = process->pid;
ptrace (PT_DETACH, pid, (void *) 1, 0);
mourn (process);
return 0;
}
/* Implement the mourn target_ops method. */
void
netbsd_process_target::mourn (struct process_info *proc)
{
proc->for_each_thread ([proc] (thread_info *thread)
{
proc->remove_thread (thread);
});
remove_process (proc);
}
/* Implement the join target_ops method. */
void
netbsd_process_target::join (int pid)
{
/* The PT_DETACH is sufficient to detach from the process.
So no need to do anything extra. */
}
/* Implement the thread_alive target_ops method. */
bool
netbsd_process_target::thread_alive (ptid_t ptid)
{
return netbsd_nat::thread_alive (ptid);
}
/* Implement the fetch_registers target_ops method. */
void
netbsd_process_target::fetch_registers (struct regcache *regcache, int regno)
{
const netbsd_regset_info *regset = get_regs_info ();
ptid_t inferior_ptid = current_thread->id;
while (regset->size >= 0)
{
std::vector<char> buf;
buf.resize (regset->size);
int res = ptrace (regset->get_request, inferior_ptid.pid (), buf.data (),
inferior_ptid.lwp ());
if (res == -1)
perror_with_name (("ptrace"));
regset->store_function (regcache, buf.data ());
regset++;
}
}
/* Implement the store_registers target_ops method. */
void
netbsd_process_target::store_registers (struct regcache *regcache, int regno)
{
const netbsd_regset_info *regset = get_regs_info ();
ptid_t inferior_ptid = current_thread->id;
while (regset->size >= 0)
{
std::vector<char> buf;
buf.resize (regset->size);
int res = ptrace (regset->get_request, inferior_ptid.pid (), buf.data (),
inferior_ptid.lwp ());
if (res == -1)
perror_with_name (("ptrace"));
/* Then overlay our cached registers on that. */
regset->fill_function (regcache, buf.data ());
/* Only now do we write the register set. */
res = ptrace (regset->set_request, inferior_ptid.pid (), buf. data (),
inferior_ptid.lwp ());
if (res == -1)
perror_with_name (("ptrace"));
regset++;
}
}
/* Implement the read_memory target_ops method. */
int
netbsd_process_target::read_memory (CORE_ADDR memaddr, unsigned char *myaddr,
int size)
{
pid_t pid = current_process ()->pid;
return netbsd_nat::read_memory (pid, myaddr, memaddr, size, nullptr);
}
/* Implement the write_memory target_ops method. */
int
netbsd_process_target::write_memory (CORE_ADDR memaddr,
const unsigned char *myaddr, int size)
{
pid_t pid = current_process ()->pid;
return netbsd_nat::write_memory (pid, myaddr, memaddr, size, nullptr);
}
/* Implement the request_interrupt target_ops method. */
void
netbsd_process_target::request_interrupt ()
{
ptid_t inferior_ptid = get_first_thread ()->id;
::kill (inferior_ptid.pid (), SIGINT);
}
/* Read the AUX Vector for the specified PID, wrapping the ptrace(2) call
with the PIOD_READ_AUXV operation and using the PT_IO standard input
and output arguments. */
static size_t
netbsd_read_auxv(pid_t pid, void *offs, void *addr, size_t len)
{
struct ptrace_io_desc pio;
pio.piod_op = PIOD_READ_AUXV;
pio.piod_offs = offs;
pio.piod_addr = addr;
pio.piod_len = len;
if (ptrace (PT_IO, pid, &pio, 0) == -1)
perror_with_name (("ptrace"));
return pio.piod_len;
}
/* Copy LEN bytes from inferior's auxiliary vector starting at OFFSET
to debugger memory starting at MYADDR. */
int
netbsd_process_target::read_auxv (int pid, CORE_ADDR offset,
unsigned char *myaddr, unsigned int len)
{
return netbsd_read_auxv (pid, (void *) (intptr_t) offset, myaddr, len);
}
bool
netbsd_process_target::supports_z_point_type (char z_type)
{
switch (z_type)
{
case Z_PACKET_SW_BP:
return true;
case Z_PACKET_HW_BP:
case Z_PACKET_WRITE_WP:
case Z_PACKET_READ_WP:
case Z_PACKET_ACCESS_WP:
default:
return false; /* Not supported. */
}
}
/* Insert {break/watch}point at address ADDR. SIZE is not used. */
int
netbsd_process_target::insert_point (enum raw_bkpt_type type, CORE_ADDR addr,
int size, struct raw_breakpoint *bp)
{
switch (type)
{
case raw_bkpt_type_sw:
return insert_memory_breakpoint (bp);
case raw_bkpt_type_hw:
case raw_bkpt_type_write_wp:
case raw_bkpt_type_read_wp:
case raw_bkpt_type_access_wp:
default:
return 1; /* Not supported. */
}
}
/* Remove {break/watch}point at address ADDR. SIZE is not used. */
int
netbsd_process_target::remove_point (enum raw_bkpt_type type, CORE_ADDR addr,
int size, struct raw_breakpoint *bp)
{
switch (type)
{
case raw_bkpt_type_sw:
return remove_memory_breakpoint (bp);
case raw_bkpt_type_hw:
case raw_bkpt_type_write_wp:
case raw_bkpt_type_read_wp:
case raw_bkpt_type_access_wp:
default:
return 1; /* Not supported. */
}
}
/* Implement the stopped_by_sw_breakpoint target_ops method. */
bool
netbsd_process_target::stopped_by_sw_breakpoint ()
{
ptrace_siginfo_t psi;
pid_t pid = current_process ()->pid;
if (ptrace (PT_GET_SIGINFO, pid, &psi, sizeof (psi)) == -1)
perror_with_name (("ptrace"));
return psi.psi_siginfo.si_signo == SIGTRAP &&
psi.psi_siginfo.si_code == TRAP_BRKPT;
}
/* Implement the supports_stopped_by_sw_breakpoint target_ops method. */
bool
netbsd_process_target::supports_stopped_by_sw_breakpoint ()
{
return true;
}
/* Implement the supports_qxfer_siginfo target_ops method. */
bool
netbsd_process_target::supports_qxfer_siginfo ()
{
return true;
}
/* Implement the qxfer_siginfo target_ops method. */
int
netbsd_process_target::qxfer_siginfo (const char *annex, unsigned char *readbuf,
unsigned const char *writebuf,
CORE_ADDR offset, int len)
{
if (current_thread == nullptr)
return -1;
pid_t pid = current_process ()->pid;
return netbsd_nat::qxfer_siginfo(pid, annex, readbuf, writebuf, offset, len);
}
/* Implement the supports_non_stop target_ops method. */
bool
netbsd_process_target::supports_non_stop ()
{
return false;
}
/* Implement the supports_multi_process target_ops method. */
bool
netbsd_process_target::supports_multi_process ()
{
return true;
}
/* Check if fork events are supported. */
bool
netbsd_process_target::supports_fork_events ()
{
return false;
}
/* Check if vfork events are supported. */
bool
netbsd_process_target::supports_vfork_events ()
{
return false;
}
/* Check if exec events are supported. */
bool
netbsd_process_target::supports_exec_events ()
{
return true;
}
/* Implement the supports_disable_randomization target_ops method. */
bool
netbsd_process_target::supports_disable_randomization ()
{
return false;
}
/* Extract &phdr and num_phdr in the inferior. Return 0 on success. */
template <typename T>
int get_phdr_phnum_from_proc_auxv (const pid_t pid,
CORE_ADDR *phdr_memaddr, int *num_phdr)
{
typedef typename std::conditional<sizeof(T) == sizeof(int64_t),
Aux64Info, Aux32Info>::type auxv_type;
const size_t auxv_size = sizeof (auxv_type);
const size_t auxv_buf_size = 128 * sizeof (auxv_type);
std::vector<char> auxv_buf;
auxv_buf.resize (auxv_buf_size);
netbsd_read_auxv (pid, nullptr, auxv_buf.data (), auxv_buf_size);
*phdr_memaddr = 0;
*num_phdr = 0;
for (char *buf = auxv_buf.data ();
buf < (auxv_buf.data () + auxv_buf_size);
buf += auxv_size)
{
auxv_type *const aux = (auxv_type *) buf;
switch (aux->a_type)
{
case AT_PHDR:
*phdr_memaddr = aux->a_v;
break;
case AT_PHNUM:
*num_phdr = aux->a_v;
break;
}
if (*phdr_memaddr != 0 && *num_phdr != 0)
break;
}
if (*phdr_memaddr == 0 || *num_phdr == 0)
{
warning ("Unexpected missing AT_PHDR and/or AT_PHNUM: "
"phdr_memaddr = %s, phdr_num = %d",
core_addr_to_string (*phdr_memaddr), *num_phdr);
return 2;
}
return 0;
}
/* Return &_DYNAMIC (via PT_DYNAMIC) in the inferior, or 0 if not present. */
template <typename T>
static CORE_ADDR
get_dynamic (const pid_t pid)
{
typedef typename std::conditional<sizeof(T) == sizeof(int64_t),
Elf64_Phdr, Elf32_Phdr>::type phdr_type;
const int phdr_size = sizeof (phdr_type);
CORE_ADDR phdr_memaddr;
int num_phdr;
if (get_phdr_phnum_from_proc_auxv<T> (pid, &phdr_memaddr, &num_phdr))
return 0;
std::vector<unsigned char> phdr_buf;
phdr_buf.resize (num_phdr * phdr_size);
if (netbsd_nat::read_memory (pid, phdr_buf.data (), phdr_memaddr,
phdr_buf.size (), nullptr))
return 0;
/* Compute relocation: it is expected to be 0 for "regular" executables,
non-zero for PIE ones. */
CORE_ADDR relocation = -1;
for (int i = 0; relocation == -1 && i < num_phdr; i++)
{
phdr_type *const p = (phdr_type *) (phdr_buf.data () + i * phdr_size);
if (p->p_type == PT_PHDR)
relocation = phdr_memaddr - p->p_vaddr;
}
if (relocation == -1)
{
/* PT_PHDR is optional, but necessary for PIE in general. Fortunately
any real world executables, including PIE executables, have always
PT_PHDR present. PT_PHDR is not present in some shared libraries or
in fpc (Free Pascal 2.4) binaries but neither of those have a need for
or present DT_DEBUG anyway (fpc binaries are statically linked).
Therefore if there exists DT_DEBUG there is always also PT_PHDR.
GDB could find RELOCATION also from AT_ENTRY - e_entry. */
return 0;
}
for (int i = 0; i < num_phdr; i++)
{
phdr_type *const p = (phdr_type *) (phdr_buf.data () + i * phdr_size);
if (p->p_type == PT_DYNAMIC)
return p->p_vaddr + relocation;
}
return 0;
}
/* Return &_r_debug in the inferior, or -1 if not present. Return value
can be 0 if the inferior does not yet have the library list initialized.
We look for DT_MIPS_RLD_MAP first. MIPS executables use this instead of
DT_DEBUG, although they sometimes contain an unused DT_DEBUG entry too. */
template <typename T>
static CORE_ADDR
get_r_debug (const pid_t pid)
{
typedef typename std::conditional<sizeof(T) == sizeof(int64_t),
Elf64_Dyn, Elf32_Dyn>::type dyn_type;
const int dyn_size = sizeof (dyn_type);
unsigned char buf[sizeof (dyn_type)]; /* The larger of the two. */
CORE_ADDR map = -1;
CORE_ADDR dynamic_memaddr = get_dynamic<T> (pid);
if (dynamic_memaddr == 0)
return map;
while (netbsd_nat::read_memory (pid, buf, dynamic_memaddr, dyn_size, nullptr)
== 0)
{
dyn_type *const dyn = (dyn_type *) buf;
#if defined DT_MIPS_RLD_MAP
union
{
T map;
unsigned char buf[sizeof (T)];
}
rld_map;
if (dyn->d_tag == DT_MIPS_RLD_MAP)
{
if (netbsd_nat::read_memory (pid, rld_map.buf, dyn->d_un.d_val,
sizeof (rld_map.buf), nullptr) == 0)
return rld_map.map;
else
break;
}
#endif /* DT_MIPS_RLD_MAP */
if (dyn->d_tag == DT_DEBUG && map == -1)
map = dyn->d_un.d_val;
if (dyn->d_tag == DT_NULL)
break;
dynamic_memaddr += dyn_size;
}
return map;
}
/* Read one pointer from MEMADDR in the inferior. */
static int
read_one_ptr (const pid_t pid, CORE_ADDR memaddr, CORE_ADDR *ptr, int ptr_size)
{
/* Go through a union so this works on either big or little endian
hosts, when the inferior's pointer size is smaller than the size
of CORE_ADDR. It is assumed the inferior's endianness is the
same of the superior's. */
union
{
CORE_ADDR core_addr;
unsigned int ui;
unsigned char uc;
} addr;
int ret = netbsd_nat::read_memory (pid, &addr.uc, memaddr, ptr_size, nullptr);
if (ret == 0)
{
if (ptr_size == sizeof (CORE_ADDR))
*ptr = addr.core_addr;
else if (ptr_size == sizeof (unsigned int))
*ptr = addr.ui;
else
gdb_assert_not_reached ("unhandled pointer size");
}
return ret;
}
/* Construct qXfer:libraries-svr4:read reply. */
template <typename T>
int
netbsd_qxfer_libraries_svr4 (const pid_t pid, const char *annex,
unsigned char *readbuf,
unsigned const char *writebuf,
CORE_ADDR offset, int len)
{
struct link_map_offsets
{
/* Offset and size of r_debug.r_version. */
int r_version_offset;
/* Offset and size of r_debug.r_map. */
int r_map_offset;
/* Offset to l_addr field in struct link_map. */
int l_addr_offset;
/* Offset to l_name field in struct link_map. */
int l_name_offset;
/* Offset to l_ld field in struct link_map. */
int l_ld_offset;
/* Offset to l_next field in struct link_map. */
int l_next_offset;
/* Offset to l_prev field in struct link_map. */
int l_prev_offset;
};
static const struct link_map_offsets lmo_32bit_offsets =
{
0, /* r_version offset. */
4, /* r_debug.r_map offset. */
0, /* l_addr offset in link_map. */
4, /* l_name offset in link_map. */
8, /* l_ld offset in link_map. */
12, /* l_next offset in link_map. */
16 /* l_prev offset in link_map. */
};
static const struct link_map_offsets lmo_64bit_offsets =
{
0, /* r_version offset. */
8, /* r_debug.r_map offset. */
0, /* l_addr offset in link_map. */
8, /* l_name offset in link_map. */
16, /* l_ld offset in link_map. */
24, /* l_next offset in link_map. */
32 /* l_prev offset in link_map. */
};
CORE_ADDR lm_addr = 0, lm_prev = 0;
CORE_ADDR l_name, l_addr, l_ld, l_next, l_prev;
int header_done = 0;
const struct link_map_offsets *lmo
= ((sizeof (T) == sizeof (int64_t))
? &lmo_64bit_offsets : &lmo_32bit_offsets);
int ptr_size = sizeof (T);
while (annex[0] != '\0')
{
const char *sep = strchr (annex, '=');
if (sep == nullptr)
break;
int name_len = sep - annex;