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Diffstat (limited to 'gdb/infptrace.c')
| -rw-r--r-- | gdb/infptrace.c | 638 |
1 files changed, 638 insertions, 0 deletions
diff --git a/gdb/infptrace.c b/gdb/infptrace.c new file mode 100644 index 00000000000..1db7223ea3b --- /dev/null +++ b/gdb/infptrace.c @@ -0,0 +1,638 @@ +/* Low level Unix child interface to ptrace, for GDB when running under Unix. + Copyright 1988, 89, 90, 91, 92, 93, 94, 95, 96, 1998 + 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 "defs.h" +#include "frame.h" +#include "inferior.h" +#include "target.h" +#include "gdb_string.h" +#include "wait.h" +#include "command.h" + +#ifdef USG +#include <sys/types.h> +#endif + +#include <sys/param.h> +#include <sys/dir.h> +#include <signal.h> +#include <sys/ioctl.h> + +#ifdef HAVE_PTRACE_H +# include <ptrace.h> +#else +# ifdef HAVE_SYS_PTRACE_H +# include <sys/ptrace.h> +# endif +#endif + +#if !defined (PT_READ_I) +#define PT_READ_I 1 /* Read word from text space */ +#endif +#if !defined (PT_READ_D) +#define PT_READ_D 2 /* Read word from data space */ +#endif +#if !defined (PT_READ_U) +#define PT_READ_U 3 /* Read word from kernel user struct */ +#endif +#if !defined (PT_WRITE_I) +#define PT_WRITE_I 4 /* Write word to text space */ +#endif +#if !defined (PT_WRITE_D) +#define PT_WRITE_D 5 /* Write word to data space */ +#endif +#if !defined (PT_WRITE_U) +#define PT_WRITE_U 6 /* Write word to kernel user struct */ +#endif +#if !defined (PT_CONTINUE) +#define PT_CONTINUE 7 /* Continue after signal */ +#endif +#if !defined (PT_STEP) +#define PT_STEP 9 /* Set flag for single stepping */ +#endif +#if !defined (PT_KILL) +#define PT_KILL 8 /* Send child a SIGKILL signal */ +#endif + +#ifndef PT_ATTACH +#define PT_ATTACH PTRACE_ATTACH +#endif +#ifndef PT_DETACH +#define PT_DETACH PTRACE_DETACH +#endif + +#include "gdbcore.h" +#ifndef NO_SYS_FILE +#include <sys/file.h> +#endif +#if 0 +/* Don't think this is used anymore. On the sequent (not sure whether it's + dynix or ptx or both), it is included unconditionally by sys/user.h and + not protected against multiple inclusion. */ +#include "gdb_stat.h" +#endif + +#if !defined (FETCH_INFERIOR_REGISTERS) +#include <sys/user.h> /* Probably need to poke the user structure */ +#if defined (KERNEL_U_ADDR_BSD) +#include <a.out.h> /* For struct nlist */ +#endif /* KERNEL_U_ADDR_BSD. */ +#endif /* !FETCH_INFERIOR_REGISTERS */ + +#if !defined (CHILD_XFER_MEMORY) +static void udot_info PARAMS ((char *, int)); +#endif + +#if !defined (FETCH_INFERIOR_REGISTERS) +static void fetch_register PARAMS ((int)); +static void store_register PARAMS ((int)); +#endif + +void _initialize_kernel_u_addr PARAMS ((void)); +void _initialize_infptrace PARAMS ((void)); + + +/* This function simply calls ptrace with the given arguments. + It exists so that all calls to ptrace are isolated in this + machine-dependent file. */ +int +call_ptrace (request, pid, addr, data) + int request, pid; + PTRACE_ARG3_TYPE addr; + int data; +{ + int pt_status = 0; + +#if 0 + int saved_errno; + + printf ("call_ptrace(request=%d, pid=%d, addr=0x%x, data=0x%x)", + request, pid, addr, data); +#endif +#if defined(PT_SETTRC) + /* If the parent can be told to attach to us, try to do it. */ + if (request == PT_SETTRC) { + errno = 0; + pt_status = ptrace (PT_SETTRC, pid, addr, data +#if defined (FIVE_ARG_PTRACE) + /* Deal with HPUX 8.0 braindamage. We never use the + calls which require the fifth argument. */ + , 0 +#endif + ); + + if (errno) perror_with_name ("ptrace"); +#if 0 + printf (" = %d\n", pt_status); +#endif + if (pt_status < 0) + return pt_status; + else + return parent_attach_all (pid, addr, data); + } +#endif + +#if defined(PT_CONTIN1) + /* On HPUX, PT_CONTIN1 is a form of continue that preserves pending + signals. If it's available, use it. */ + if (request == PT_CONTINUE) + request = PT_CONTIN1; +#endif + +#if defined(PT_SINGLE1) + /* On HPUX, PT_SINGLE1 is a form of step that preserves pending + signals. If it's available, use it. */ + if (request == PT_STEP) + request = PT_SINGLE1; +#endif + +#if 0 + saved_errno = errno; + errno = 0; +#endif + pt_status = ptrace (request, pid, addr, data +#if defined (FIVE_ARG_PTRACE) + /* Deal with HPUX 8.0 braindamage. We never use the + calls which require the fifth argument. */ + , 0 +#endif + ); +#if 0 + if (errno) + printf (" [errno = %d]", errno); + + errno = saved_errno; + printf (" = 0x%x\n", pt_status); +#endif + return pt_status; +} + + +#if defined (DEBUG_PTRACE) || defined (FIVE_ARG_PTRACE) +/* For the rest of the file, use an extra level of indirection */ +/* This lets us breakpoint usefully on call_ptrace. */ +#define ptrace call_ptrace +#endif + +/* Wait for a process to finish, possibly running a target-specific + hook before returning. */ + +int +ptrace_wait (pid, status) + int pid; + int *status; +{ + int wstate; + + wstate = wait (status); + target_post_wait (wstate, *status); + return wstate; +} + +void +kill_inferior () +{ + int status; + + if (inferior_pid == 0) + return; + + /* This once used to call "kill" to kill the inferior just in case + the inferior was still running. As others have noted in the past + (kingdon) there shouldn't be any way to get here if the inferior + is still running -- else there's a major problem elsewere in gdb + and it needs to be fixed. + + The kill call causes problems under hpux10, so it's been removed; + if this causes problems we'll deal with them as they arise. */ + ptrace (PT_KILL, inferior_pid, (PTRACE_ARG3_TYPE) 0, 0); + ptrace_wait (0, &status); + target_mourn_inferior (); +} + +#ifndef CHILD_RESUME + +/* Resume execution of the inferior process. + If STEP is nonzero, single-step it. + If SIGNAL is nonzero, give it that signal. */ + +void +child_resume (pid, step, signal) + int pid; + int step; + enum target_signal signal; +{ + errno = 0; + + if (pid == -1) + /* Resume all threads. */ + /* I think this only gets used in the non-threaded case, where "resume + all threads" and "resume inferior_pid" are the same. */ + pid = inferior_pid; + + /* An address of (PTRACE_ARG3_TYPE)1 tells ptrace to continue from where + it was. (If GDB wanted it to start some other way, we have already + written a new PC value to the child.) + + If this system does not support PT_STEP, a higher level function will + have called single_step() to transmute the step request into a + continue request (by setting breakpoints on all possible successor + instructions), so we don't have to worry about that here. */ + + if (step) + { + if (SOFTWARE_SINGLE_STEP_P) + abort(); /* Make sure this doesn't happen. */ + else + ptrace (PT_STEP, pid, (PTRACE_ARG3_TYPE) 1, + target_signal_to_host (signal)); + } + else + ptrace (PT_CONTINUE, pid, (PTRACE_ARG3_TYPE) 1, + target_signal_to_host (signal)); + + if (errno) + perror_with_name ("ptrace"); +} +#endif /* CHILD_RESUME */ + + +#ifdef ATTACH_DETACH +/* Start debugging the process whose number is PID. */ +int +attach (pid) + int pid; +{ + errno = 0; + ptrace (PT_ATTACH, pid, (PTRACE_ARG3_TYPE) 0, 0); + if (errno) + perror_with_name ("ptrace"); + attach_flag = 1; + return pid; +} + +/* Stop debugging the process whose number is PID + and continue it with signal number SIGNAL. + SIGNAL = 0 means just continue it. */ + +void +detach (signal) + int signal; +{ + errno = 0; + ptrace (PT_DETACH, inferior_pid, (PTRACE_ARG3_TYPE) 1, signal); + if (errno) + perror_with_name ("ptrace"); + attach_flag = 0; +} +#endif /* ATTACH_DETACH */ + +/* Default the type of the ptrace transfer to int. */ +#ifndef PTRACE_XFER_TYPE +#define PTRACE_XFER_TYPE int +#endif + +/* KERNEL_U_ADDR is the amount to subtract from u.u_ar0 + to get the offset in the core file of the register values. */ +#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS) +/* Get kernel_u_addr using BSD-style nlist(). */ +CORE_ADDR kernel_u_addr; +#endif /* KERNEL_U_ADDR_BSD. */ + +void +_initialize_kernel_u_addr () +{ +#if defined (KERNEL_U_ADDR_BSD) && !defined (FETCH_INFERIOR_REGISTERS) + struct nlist names[2]; + + names[0].n_un.n_name = "_u"; + names[1].n_un.n_name = NULL; + if (nlist ("/vmunix", names) == 0) + kernel_u_addr = names[0].n_value; + else + fatal ("Unable to get kernel u area address."); +#endif /* KERNEL_U_ADDR_BSD. */ +} + +#if !defined (FETCH_INFERIOR_REGISTERS) + +#if !defined (offsetof) +#define offsetof(TYPE, MEMBER) ((unsigned long) &((TYPE *)0)->MEMBER) +#endif + +/* U_REGS_OFFSET is the offset of the registers within the u area. */ +#if !defined (U_REGS_OFFSET) +#define U_REGS_OFFSET \ + ptrace (PT_READ_U, inferior_pid, \ + (PTRACE_ARG3_TYPE) (offsetof (struct user, u_ar0)), 0) \ + - KERNEL_U_ADDR +#endif + +/* Registers we shouldn't try to fetch. */ +#if !defined (CANNOT_FETCH_REGISTER) +#define CANNOT_FETCH_REGISTER(regno) 0 +#endif + +/* Fetch one register. */ + +static void +fetch_register (regno) + int regno; +{ + /* This isn't really an address. But ptrace thinks of it as one. */ + CORE_ADDR regaddr; + char mess[128]; /* For messages */ + register int i; + unsigned int offset; /* Offset of registers within the u area. */ + char buf[MAX_REGISTER_RAW_SIZE]; + + if (CANNOT_FETCH_REGISTER (regno)) + { + memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */ + supply_register (regno, buf); + return; + } + + offset = U_REGS_OFFSET; + + regaddr = register_addr (regno, offset); + for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof (PTRACE_XFER_TYPE)) + { + errno = 0; + *(PTRACE_XFER_TYPE *) &buf[i] = ptrace (PT_READ_U, inferior_pid, + (PTRACE_ARG3_TYPE) regaddr, 0); + regaddr += sizeof (PTRACE_XFER_TYPE); + if (errno != 0) + { + sprintf (mess, "reading register %s (#%d)", REGISTER_NAME (regno), regno); + perror_with_name (mess); + } + } + supply_register (regno, buf); +} + + +/* Fetch register values from the inferior. + If REGNO is negative, do this for all registers. + Otherwise, REGNO specifies which register (so we can save time). */ + +void +fetch_inferior_registers (regno) + int regno; +{ + if (regno >= 0) + { + fetch_register (regno); + } + else + { + for (regno = 0; regno < ARCH_NUM_REGS; regno++) + { + fetch_register (regno); + } + } +} + +/* Registers we shouldn't try to store. */ +#if !defined (CANNOT_STORE_REGISTER) +#define CANNOT_STORE_REGISTER(regno) 0 +#endif + +/* Store one register. */ + +static void +store_register (regno) + int regno; +{ + /* This isn't really an address. But ptrace thinks of it as one. */ + CORE_ADDR regaddr; + char mess[128]; /* For messages */ + register int i; + unsigned int offset; /* Offset of registers within the u area. */ + + if (CANNOT_STORE_REGISTER (regno)) + { + return; + } + + offset = U_REGS_OFFSET; + + regaddr = register_addr (regno, offset); + for (i = 0; i < REGISTER_RAW_SIZE (regno); i += sizeof(PTRACE_XFER_TYPE)) + { + errno = 0; + ptrace (PT_WRITE_U, inferior_pid, (PTRACE_ARG3_TYPE) regaddr, + *(PTRACE_XFER_TYPE *) ®isters[REGISTER_BYTE (regno) + i]); + regaddr += sizeof (PTRACE_XFER_TYPE); + if (errno != 0) + { + sprintf (mess, "writing register %s (#%d)", REGISTER_NAME (regno), regno); + perror_with_name (mess); + } + } +} + +/* Store our register values back into the inferior. + If REGNO is negative, do this for all registers. + Otherwise, REGNO specifies which register (so we can save time). */ + +void +store_inferior_registers (regno) + int regno; +{ + if (regno >= 0) + { + store_register (regno); + } + else + { + for (regno = 0; regno < ARCH_NUM_REGS; regno++) + { + store_register (regno); + } + } +} +#endif /* !defined (FETCH_INFERIOR_REGISTERS). */ + + +#if !defined (CHILD_XFER_MEMORY) +/* NOTE! I tried using PTRACE_READDATA, etc., to read and write memory + in the NEW_SUN_PTRACE case. + It ought to be straightforward. But it appears that writing did + not write the data that I specified. I cannot understand where + it got the data that it actually did write. */ + +/* Copy LEN bytes to or from inferior's memory starting at MEMADDR + to debugger memory starting at MYADDR. Copy to inferior if + WRITE is nonzero. + + Returns the length copied, which is either the LEN argument or zero. + This xfer function does not do partial moves, since child_ops + doesn't allow memory operations to cross below us in the target stack + anyway. */ + +int +child_xfer_memory (memaddr, myaddr, len, write, target) + CORE_ADDR memaddr; + char *myaddr; + int len; + int write; + struct target_ops *target; /* ignored */ +{ + register int i; + /* Round starting address down to longword boundary. */ + register CORE_ADDR addr = memaddr & - 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)); + + if (write) + { + /* Fill start and end extra bytes of buffer with existing memory data. */ + + if (addr != memaddr || len < (int) sizeof (PTRACE_XFER_TYPE)) { + /* Need part of initial word -- fetch it. */ + buffer[0] = ptrace (PT_READ_I, inferior_pid, (PTRACE_ARG3_TYPE) addr, + 0); + } + + if (count > 1) /* FIXME, avoid if even boundary */ + { + buffer[count - 1] + = ptrace (PT_READ_I, 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 (PT_WRITE_D, inferior_pid, (PTRACE_ARG3_TYPE) addr, + buffer[i]); + if (errno) + { + /* Using the appropriate one (I or D) is necessary for + Gould NP1, at least. */ + errno = 0; + ptrace (PT_WRITE_I, inferior_pid, (PTRACE_ARG3_TYPE) addr, + buffer[i]); + } + if (errno) + return 0; + } +#ifdef CLEAR_INSN_CACHE + CLEAR_INSN_CACHE(); +#endif + } + else + { + /* Read all the longwords */ + for (i = 0; i < count; i++, addr += sizeof (PTRACE_XFER_TYPE)) + { + errno = 0; + buffer[i] = ptrace (PT_READ_I, inferior_pid, + (PTRACE_ARG3_TYPE) addr, 0); + if (errno) + return 0; + QUIT; + } + + /* Copy appropriate bytes out of the buffer. */ + memcpy (myaddr, + (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)), + len); + } + return len; +} + + +static void +udot_info (dummy1, dummy2) + char *dummy1; + int dummy2; +{ +#if defined (KERNEL_U_SIZE) + int udot_off; /* Offset into user struct */ + int udot_val; /* Value from user struct at udot_off */ + char mess[128]; /* For messages */ +#endif + + if (!target_has_execution) + { + error ("The program is not being run."); + } + +#if !defined (KERNEL_U_SIZE) + + /* Adding support for this command is easy. Typically you just add a + routine, called "kernel_u_size" that returns the size of the user + struct, to the appropriate *-nat.c file and then add to the native + config file "#define KERNEL_U_SIZE kernel_u_size()" */ + error ("Don't know how large ``struct user'' is in this version of gdb."); + +#else + + for (udot_off = 0; udot_off < KERNEL_U_SIZE; udot_off += sizeof (udot_val)) + { + if ((udot_off % 24) == 0) + { + if (udot_off > 0) + { + printf_filtered ("\n"); + } + printf_filtered ("%04x:", udot_off); + } + udot_val = ptrace (PT_READ_U, inferior_pid, (PTRACE_ARG3_TYPE) udot_off, 0); + if (errno != 0) + { + sprintf (mess, "\nreading user struct at offset 0x%x", udot_off); + perror_with_name (mess); + } + /* Avoid using nonportable (?) "*" in print specs */ + printf_filtered (sizeof (int) == 4 ? " 0x%08x" : " 0x%16x", udot_val); + } + printf_filtered ("\n"); + +#endif +} +#endif /* !defined (CHILD_XFER_MEMORY). */ + + +void +_initialize_infptrace () +{ +#if !defined (CHILD_XFER_MEMORY) + add_info ("udot", udot_info, + "Print contents of kernel ``struct user'' for current child."); +#endif +} |