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- /* Copyright (C) 2020-2022 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 "server.h"
- #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::vector<char *> &program_args)
- {
- std::string str_program_args = construct_inferior_arguments (program_args);
- pid_t pid = fork_inferior (program, str_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 = ptid_of (current_thread);
- 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::handle_eintr (-1, ::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);
- 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
- {
- add_thread (wptid, NULL);
- 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)
- 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::handle_eintr (-1, ::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)
- {
- for_each_thread (proc->pid, remove_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 = ptid_of (current_thread);
- 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 = ptid_of (current_thread);
- 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 = ptid_of (get_first_thread ());
- ::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 (CORE_ADDR offset,
- unsigned char *myaddr, unsigned int len)
- {
- pid_t pid = pid_of (current_thread);
- 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;
- CORE_ADDR *addrp;
- if (name_len == 5 && startswith (annex, "start"))
- addrp = &lm_addr;
- else if (name_len == 4 && startswith (annex, "prev"))
- addrp = &lm_prev;
- else
- {
- annex = strchr (sep, ';');
- if (annex == nullptr)
- break;
- annex++;
- continue;
- }
- annex = decode_address_to_semicolon (addrp, sep + 1);
- }
- if (lm_addr == 0)
- {
- CORE_ADDR r_debug = get_r_debug<T> (pid);
- /* We failed to find DT_DEBUG. Such situation will not change
- for this inferior - do not retry it. Report it to GDB as
- E01, see for the reasons at the GDB solib-svr4.c side. */
- if (r_debug == (CORE_ADDR) -1)
- return -1;
- if (r_debug != 0)
- {
- CORE_ADDR map_offset = r_debug + lmo->r_map_offset;
- if (read_one_ptr (pid, map_offset, &lm_addr, ptr_size) != 0)
- warning ("unable to read r_map from %s",
- core_addr_to_string (map_offset));
- }
- }
- std::string document = "<library-list-svr4 version=\"1.0\"";
- while (lm_addr
- && read_one_ptr (pid, lm_addr + lmo->l_name_offset,
- &l_name, ptr_size) == 0
- && read_one_ptr (pid, lm_addr + lmo->l_addr_offset,
- &l_addr, ptr_size) == 0
- && read_one_ptr (pid, lm_addr + lmo->l_ld_offset,
- &l_ld, ptr_size) == 0
- && read_one_ptr (pid, lm_addr + lmo->l_prev_offset,
- &l_prev, ptr_size) == 0
- && read_one_ptr (pid, lm_addr + lmo->l_next_offset,
- &l_next, ptr_size) == 0)
- {
- if (lm_prev != l_prev)
- {
- warning ("Corrupted shared library list: 0x%lx != 0x%lx",
- (long) lm_prev, (long) l_prev);
- break;
- }
- /* Ignore the first entry even if it has valid name as the first entry
- corresponds to the main executable. The first entry should not be
- skipped if the dynamic loader was loaded late by a static executable
- (see solib-svr4.c parameter ignore_first). But in such case the main
- executable does not have PT_DYNAMIC present and this function already
- exited above due to failed get_r_debug. */
- if (lm_prev == 0)
- string_appendf (document, " main-lm=\"0x%lx\"",
- (unsigned long) lm_addr);
- else
- {
- unsigned char libname[PATH_MAX];
- /* Not checking for error because reading may stop before
- we've got PATH_MAX worth of characters. */
- libname[0] = '\0';
- netbsd_nat::read_memory (pid, libname, l_name, sizeof (libname) - 1,
- nullptr);
- libname[sizeof (libname) - 1] = '\0';
- if (libname[0] != '\0')
- {
- if (!header_done)
- {
- /* Terminate `<library-list-svr4'. */
- document += '>';
- header_done = 1;
- }
- string_appendf (document, "<library name=\"");
- xml_escape_text_append (&document, (char *) libname);
- string_appendf (document, "\" lm=\"0x%lx\" "
- "l_addr=\"0x%lx\" l_ld=\"0x%lx\"/>",
- (unsigned long) lm_addr, (unsigned long) l_addr,
- (unsigned long) l_ld);
- }
- }
- lm_prev = lm_addr;
- lm_addr = l_next;
- }
- if (!header_done)
- {
- /* Empty list; terminate `<library-list-svr4'. */
- document += "/>";
- }
- else
- document += "</library-list-svr4>";
- int document_len = document.length ();
- if (offset < document_len)
- document_len -= offset;
- else
- document_len = 0;
- if (len > document_len)
- len = document_len;
- memcpy (readbuf, document.data () + offset, len);
- return len;
- }
- /* Return true if FILE is a 64-bit ELF file,
- false if the file is not a 64-bit ELF file,
- and error if the file is not accessible or doesn't exist. */
- static bool
- elf_64_file_p (const char *file)
- {
- int fd = gdb::handle_eintr (-1, ::open, file, O_RDONLY);
- if (fd < 0)
- perror_with_name (("open"));
- Elf64_Ehdr header;
- ssize_t ret = gdb::handle_eintr (-1, ::read, fd, &header, sizeof (header));
- if (ret == -1)
- perror_with_name (("read"));
- gdb::handle_eintr (-1, ::close, fd);
- if (ret != sizeof (header))
- error ("Cannot read ELF file header: %s", file);
- if (header.e_ident[EI_MAG0] != ELFMAG0
- || header.e_ident[EI_MAG1] != ELFMAG1
- || header.e_ident[EI_MAG2] != ELFMAG2
- || header.e_ident[EI_MAG3] != ELFMAG3)
- error ("Unrecognized ELF file header: %s", file);
- return header.e_ident[EI_CLASS] == ELFCLASS64;
- }
- /* Construct qXfer:libraries-svr4:read reply. */
- int
- netbsd_process_target::qxfer_libraries_svr4 (const char *annex,
- unsigned char *readbuf,
- unsigned const char *writebuf,
- CORE_ADDR offset, int len)
- {
- if (writebuf != nullptr)
- return -2;
- if (readbuf == nullptr)
- return -1;
- struct process_info *proc = current_process ();
- pid_t pid = proc->pid;
- bool is_elf64 = elf_64_file_p (netbsd_nat::pid_to_exec_file (pid));
- if (is_elf64)
- return netbsd_qxfer_libraries_svr4<int64_t> (pid, annex, readbuf,
- writebuf, offset, len);
- else
- return netbsd_qxfer_libraries_svr4<int32_t> (pid, annex, readbuf,
- writebuf, offset, len);
- }
- /* Implement the supports_qxfer_libraries_svr4 target_ops method. */
- bool
- netbsd_process_target::supports_qxfer_libraries_svr4 ()
- {
- return true;
- }
- /* Return the name of a file that can be opened to get the symbols for
- the child process identified by PID. */
- const char *
- netbsd_process_target::pid_to_exec_file (pid_t pid)
- {
- return netbsd_nat::pid_to_exec_file (pid);
- }
- /* Implementation of the target_ops method "supports_pid_to_exec_file". */
- bool
- netbsd_process_target::supports_pid_to_exec_file ()
- {
- return true;
- }
- /* Implementation of the target_ops method "supports_hardware_single_step". */
- bool
- netbsd_process_target::supports_hardware_single_step ()
- {
- return true;
- }
- /* Implementation of the target_ops method "sw_breakpoint_from_kind". */
- const gdb_byte *
- netbsd_process_target::sw_breakpoint_from_kind (int kind, int *size)
- {
- static gdb_byte brkpt[PTRACE_BREAKPOINT_SIZE] = {*PTRACE_BREAKPOINT};
- *size = PTRACE_BREAKPOINT_SIZE;
- return brkpt;
- }
- /* Implement the thread_name target_ops method. */
- const char *
- netbsd_process_target::thread_name (ptid_t ptid)
- {
- return netbsd_nat::thread_name (ptid);
- }
- /* Implement the supports_catch_syscall target_ops method. */
- bool
- netbsd_process_target::supports_catch_syscall ()
- {
- return true;
- }
- /* Implement the supports_read_auxv target_ops method. */
- bool
- netbsd_process_target::supports_read_auxv ()
- {
- return true;
- }
- void
- initialize_low ()
- {
- set_target_ops (the_netbsd_target);
- }
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