| /* Low level interface to ptrace, for the remote server for GDB. |
| Copyright 1995, 1996, 1998, 1999, 2000, 2001, 2002 |
| 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 2 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, write to the Free Software |
| Foundation, Inc., 59 Temple Place - Suite 330, |
| Boston, MA 02111-1307, USA. */ |
| |
| #include "server.h" |
| #include "linux-low.h" |
| |
| #include <sys/wait.h> |
| #include <stdio.h> |
| #include <sys/param.h> |
| #include <sys/dir.h> |
| #include <sys/ptrace.h> |
| #include <sys/user.h> |
| #include <signal.h> |
| #include <sys/ioctl.h> |
| #include <fcntl.h> |
| #include <string.h> |
| #include <stdlib.h> |
| #include <unistd.h> |
| |
| #define PTRACE_ARG3_TYPE long |
| #define PTRACE_XFER_TYPE long |
| |
| #ifdef HAVE_LINUX_REGSETS |
| static int use_regsets_p = 1; |
| #endif |
| |
| extern int errno; |
| |
| #ifdef HAVE_LINUX_USRREGS |
| extern int num_regs; |
| extern int regmap[]; |
| #endif |
| |
| /* Start an inferior process and returns its pid. |
| ALLARGS is a vector of program-name and args. */ |
| |
| int |
| create_inferior (char *program, char **allargs) |
| { |
| int pid; |
| |
| pid = fork (); |
| if (pid < 0) |
| perror_with_name ("fork"); |
| |
| if (pid == 0) |
| { |
| ptrace (PTRACE_TRACEME, 0, 0, 0); |
| |
| execv (program, allargs); |
| |
| fprintf (stderr, "Cannot exec %s: %s.\n", program, |
| strerror (errno)); |
| fflush (stderr); |
| _exit (0177); |
| } |
| |
| return pid; |
| } |
| |
| /* Attach to an inferior process. */ |
| |
| int |
| myattach (int pid) |
| { |
| if (ptrace (PTRACE_ATTACH, pid, 0, 0) != 0) |
| { |
| fprintf (stderr, "Cannot attach to process %d: %s (%d)\n", pid, |
| errno < sys_nerr ? sys_errlist[errno] : "unknown error", |
| errno); |
| fflush (stderr); |
| _exit (0177); |
| } |
| |
| return 0; |
| } |
| |
| /* Kill the inferior process. Make us have no inferior. */ |
| |
| void |
| kill_inferior (void) |
| { |
| if (inferior_pid == 0) |
| return; |
| ptrace (PTRACE_KILL, inferior_pid, 0, 0); |
| wait (0); |
| } |
| |
| /* Return nonzero if the given thread is still alive. */ |
| int |
| mythread_alive (int pid) |
| { |
| return 1; |
| } |
| |
| /* Wait for process, returns status */ |
| |
| unsigned char |
| mywait (char *status) |
| { |
| int pid; |
| int w; |
| |
| enable_async_io (); |
| pid = waitpid (inferior_pid, &w, 0); |
| disable_async_io (); |
| if (pid != inferior_pid) |
| perror_with_name ("wait"); |
| |
| if (WIFEXITED (w)) |
| { |
| fprintf (stderr, "\nChild exited with retcode = %x \n", WEXITSTATUS (w)); |
| *status = 'W'; |
| return ((unsigned char) WEXITSTATUS (w)); |
| } |
| else if (!WIFSTOPPED (w)) |
| { |
| fprintf (stderr, "\nChild terminated with signal = %x \n", WTERMSIG (w)); |
| *status = 'X'; |
| return ((unsigned char) WTERMSIG (w)); |
| } |
| |
| fetch_inferior_registers (0); |
| |
| *status = 'T'; |
| return ((unsigned char) WSTOPSIG (w)); |
| } |
| |
| /* Resume execution of the inferior process. |
| If STEP is nonzero, single-step it. |
| If SIGNAL is nonzero, give it that signal. */ |
| |
| void |
| myresume (int step, int signal) |
| { |
| errno = 0; |
| ptrace (step ? PTRACE_SINGLESTEP : PTRACE_CONT, inferior_pid, 1, signal); |
| if (errno) |
| perror_with_name ("ptrace"); |
| } |
| |
| |
| #ifdef HAVE_LINUX_USRREGS |
| |
| #define REGISTER_RAW_SIZE(regno) register_size((regno)) |
| |
| int |
| register_addr (int regnum) |
| { |
| int addr; |
| |
| if (regnum < 0 || regnum >= num_regs) |
| error ("Invalid register number %d.", regnum); |
| |
| addr = regmap[regnum]; |
| if (addr == -1) |
| addr = 0; |
| |
| return addr; |
| } |
| |
| /* Fetch one register. */ |
| static void |
| fetch_register (int regno) |
| { |
| CORE_ADDR regaddr; |
| register int i; |
| |
| if (regno >= num_regs) |
| return; |
| if (cannot_fetch_register (regno)) |
| return; |
| |
| regaddr = register_addr (regno); |
| if (regaddr == -1) |
| return; |
| for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| { |
| errno = 0; |
| *(PTRACE_XFER_TYPE *) (register_data (regno) + i) = |
| ptrace (PTRACE_PEEKUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, 0); |
| regaddr += sizeof (PTRACE_XFER_TYPE); |
| if (errno != 0) |
| { |
| /* Warning, not error, in case we are attached; sometimes the |
| kernel doesn't let us at the registers. */ |
| char *err = strerror (errno); |
| char *msg = alloca (strlen (err) + 128); |
| sprintf (msg, "reading register %d: %s", regno, err); |
| error (msg); |
| goto error_exit; |
| } |
| } |
| error_exit:; |
| } |
| |
| /* Fetch all registers, or just one, from the child process. */ |
| static void |
| usr_fetch_inferior_registers (int regno) |
| { |
| if (regno == -1 || regno == 0) |
| for (regno = 0; regno < num_regs; regno++) |
| fetch_register (regno); |
| else |
| fetch_register (regno); |
| } |
| |
| /* Store our register values back into the inferior. |
| If REGNO is -1, do this for all registers. |
| Otherwise, REGNO specifies which register (so we can save time). */ |
| static void |
| usr_store_inferior_registers (int regno) |
| { |
| CORE_ADDR regaddr; |
| int i; |
| |
| if (regno >= 0) |
| { |
| if (regno >= num_regs) |
| return; |
| |
| if (cannot_store_register (regno)) |
| return; |
| |
| regaddr = register_addr (regno); |
| if (regaddr == -1) |
| return; |
| errno = 0; |
| for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) |
| { |
| errno = 0; |
| ptrace (PTRACE_POKEUSER, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, |
| *(int *) (register_data (regno) + i)); |
| if (errno != 0) |
| { |
| /* Warning, not error, in case we are attached; sometimes the |
| kernel doesn't let us at the registers. */ |
| char *err = strerror (errno); |
| char *msg = alloca (strlen (err) + 128); |
| sprintf (msg, "writing register %d: %s", |
| regno, err); |
| error (msg); |
| return; |
| } |
| regaddr += sizeof (int); |
| } |
| } |
| else |
| for (regno = 0; regno < num_regs; regno++) |
| store_inferior_registers (regno); |
| } |
| #endif /* HAVE_LINUX_USRREGS */ |
| |
| |
| |
| #ifdef HAVE_LINUX_REGSETS |
| |
| static int |
| regsets_fetch_inferior_registers (void) |
| { |
| struct regset_info *regset; |
| |
| regset = target_regsets; |
| |
| while (regset->size >= 0) |
| { |
| void *buf; |
| int res; |
| |
| if (regset->size == 0) |
| { |
| regset ++; |
| continue; |
| } |
| |
| buf = malloc (regset->size); |
| res = ptrace (regset->get_request, inferior_pid, 0, (int) buf); |
| if (res < 0) |
| { |
| if (errno == EIO) |
| { |
| /* If we get EIO on the first regset, do not try regsets again. |
| If we get EIO on a later regset, disable that regset. */ |
| if (regset == target_regsets) |
| { |
| use_regsets_p = 0; |
| return -1; |
| } |
| else |
| { |
| regset->size = 0; |
| continue; |
| } |
| } |
| else |
| { |
| perror ("Warning: ptrace(regsets_fetch_inferior_registers)"); |
| } |
| } |
| regset->store_function (buf); |
| regset ++; |
| } |
| } |
| |
| static int |
| regsets_store_inferior_registers (void) |
| { |
| struct regset_info *regset; |
| |
| regset = target_regsets; |
| |
| while (regset->size >= 0) |
| { |
| void *buf; |
| int res; |
| |
| if (regset->size == 0) |
| { |
| regset ++; |
| continue; |
| } |
| |
| buf = malloc (regset->size); |
| regset->fill_function (buf); |
| res = ptrace (regset->set_request, inferior_pid, 0, (int) buf); |
| if (res < 0) |
| { |
| if (errno == EIO) |
| { |
| /* If we get EIO on the first regset, do not try regsets again. |
| If we get EIO on a later regset, disable that regset. */ |
| if (regset == target_regsets) |
| { |
| use_regsets_p = 0; |
| return -1; |
| } |
| else |
| { |
| regset->size = 0; |
| continue; |
| } |
| } |
| else |
| { |
| perror ("Warning: ptrace(regsets_fetch_inferior_registers)"); |
| } |
| } |
| regset ++; |
| } |
| } |
| |
| #endif /* HAVE_LINUX_REGSETS */ |
| |
| |
| void |
| fetch_inferior_registers (int regno) |
| { |
| #ifdef HAVE_LINUX_REGSETS |
| if (use_regsets_p) |
| { |
| if (regsets_fetch_inferior_registers () == 0) |
| return; |
| } |
| #endif |
| #ifdef HAVE_LINUX_USRREGS |
| usr_fetch_inferior_registers (regno); |
| #endif |
| } |
| |
| void |
| store_inferior_registers (int regno) |
| { |
| #ifdef HAVE_LINUX_REGSETS |
| if (use_regsets_p) |
| { |
| if (regsets_store_inferior_registers () == 0) |
| return; |
| } |
| #endif |
| #ifdef HAVE_LINUX_USRREGS |
| usr_store_inferior_registers (regno); |
| #endif |
| } |
| |
| |
| /* Copy LEN bytes from inferior's memory starting at MEMADDR |
| to debugger memory starting at MYADDR. */ |
| |
| void |
| read_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len) |
| { |
| register int i; |
| /* Round starting address down to longword boundary. */ |
| register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| /* Round ending address up; get number of longwords that makes. */ |
| register int count |
| = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) |
| / sizeof (PTRACE_XFER_TYPE); |
| /* Allocate buffer of that many longwords. */ |
| register PTRACE_XFER_TYPE *buffer |
| = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| |
| /* Read all the longwords */ |
| for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| { |
| buffer[i] = ptrace (PTRACE_PEEKTEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, 0); |
| } |
| |
| /* Copy appropriate bytes out of the buffer. */ |
| memcpy (myaddr, (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), len); |
| } |
| |
| /* Copy LEN bytes of data from debugger memory at MYADDR |
| to inferior's memory at MEMADDR. |
| On failure (cannot write the inferior) |
| returns the value of errno. */ |
| |
| int |
| write_inferior_memory (CORE_ADDR memaddr, char *myaddr, int len) |
| { |
| register int i; |
| /* Round starting address down to longword boundary. */ |
| register CORE_ADDR addr = memaddr & -(CORE_ADDR) sizeof (PTRACE_XFER_TYPE); |
| /* Round ending address up; get number of longwords that makes. */ |
| register int count |
| = (((memaddr + len) - addr) + sizeof (PTRACE_XFER_TYPE) - 1) / sizeof (PTRACE_XFER_TYPE); |
| /* Allocate buffer of that many longwords. */ |
| register PTRACE_XFER_TYPE *buffer = (PTRACE_XFER_TYPE *) alloca (count * sizeof (PTRACE_XFER_TYPE)); |
| extern int errno; |
| |
| /* Fill start and end extra bytes of buffer with existing memory data. */ |
| |
| buffer[0] = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
| (PTRACE_ARG3_TYPE) addr, 0); |
| |
| if (count > 1) |
| { |
| buffer[count - 1] |
| = ptrace (PTRACE_PEEKTEXT, inferior_pid, |
| (PTRACE_ARG3_TYPE) (addr + (count - 1) |
| * sizeof (PTRACE_XFER_TYPE)), |
| 0); |
| } |
| |
| /* Copy data to be written over corresponding part of buffer */ |
| |
| memcpy ((char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), myaddr, len); |
| |
| /* Write the entire buffer. */ |
| |
| for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) |
| { |
| errno = 0; |
| ptrace (PTRACE_POKETEXT, inferior_pid, (PTRACE_ARG3_TYPE) addr, buffer[i]); |
| if (errno) |
| return errno; |
| } |
| |
| return 0; |
| } |
| |
| void |
| initialize_low (void) |
| { |
| init_registers (); |
| } |