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Re: [RFA] x86-64-linux-nat.c cleanup
- From: Michal Ludvig <mludvig at suse dot cz>
- To: Michal Ludvig <mludvig at suse dot cz>
- Cc: gdb-patches at sources dot redhat dot com
- Date: Tue, 09 Apr 2002 22:04:19 +0200
- Subject: Re: [RFA] x86-64-linux-nat.c cleanup
- Organization: SuSE CR
- References: <3CB34860.3000704@suse.cz>
Oops, sorry, I forgot to include the ChangeLog (it's too late :-)
2002-04-09 Michal Ludvig <mludvig@suse.cz>
* x86-64-linux-nat.c (child_resume, child_xfer_memory): Delete.
(PTRACE_XFER_TYPE): Moved to config/i386/nm-x86-64.h.
* config/i386/nm-x86-64.h (CHILD_XFER_MEMORY, CHILD_RESUME):
Delete.
(PTRACE_XFER_TYPE): Moved here from config/i386/nm-x86-64.h.
-- ML
Michal Ludvig wrote:
> Hi all,
> because x86-64 ptrace() now conforms to standards, I removed our
> versions of child_resume and child_xfer_memory from x86-64-linux.nat.c
> and started to use those from infptrace.c. This is an obvious change,
> but quite large, so I'm sending it for approval first.
> So, can I commit?
>
> Michal Ludvig
>
>
> ------------------------------------------------------------------------
>
> Index: x86-64-linux-nat.c
> ===================================================================
> RCS file: /cvs/src/src/gdb/x86-64-linux-nat.c,v
> retrieving revision 1.8
> diff -c -3 -p -r1.8 x86-64-linux-nat.c
> *** x86-64-linux-nat.c 4 Apr 2002 13:18:59 -0000 1.8
> --- x86-64-linux-nat.c 9 Apr 2002 19:52:17 -0000
> *************** x86_64_linux_dr_get_status (void)
> *** 128,135 ****
> (0 <= (regno) && (regno) < x86_64_num_gregs)
> #define GETFPREGS_SUPPLIES(regno) \
> (FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM)
> -
> - #define PTRACE_XFER_TYPE unsigned long
>
>
> /* Transfering the general-purpose registers between GDB, inferiors
> --- 128,133 ----
> *************** static const unsigned char linux_syscall
> *** 344,507 ****
> /* Offset to saved processor registers from <asm/ucontext.h> */
> #define LINUX_UCONTEXT_SIGCONTEXT_OFFSET (36)
>
> - /* Resume execution of the inferior process.
> - If STEP is nonzero, single-step it.
> - If SIGNAL is nonzero, give it that signal. */
> -
> - void
> - child_resume (ptid_t ptid, int step, enum target_signal signal)
> - {
> - int pid = PIDGET (ptid);
> - int request = PTRACE_CONT;
> -
> - if (pid == -1)
> - /* Resume all threads. */
> - /* I think this only gets used in the non-threaded case, where "resume
> - all threads" and "resume inferior_ptid" are the same. */
> - pid = PIDGET (inferior_ptid);
> -
> - if (step)
> - {
> - CORE_ADDR pc = read_pc_pid (pid_to_ptid (pid));
> - unsigned char buf[LINUX_SYSCALL_LEN];
> -
> - request = PTRACE_SINGLESTEP;
> -
> - /* Returning from a signal trampoline is done by calling a
> - special system call (sigreturn or rt_sigreturn, see
> - i386-linux-tdep.c for more information). This system call
> - restores the registers that were saved when the signal was
> - raised, including %eflags. That means that single-stepping
> - won't work. Instead, we'll have to modify the signal context
> - that's about to be restored, and set the trace flag there. */
> -
> - /* First check if PC is at a system call. */
> - if (read_memory_nobpt (pc, (char *) buf, LINUX_SYSCALL_LEN) == 0
> - && memcmp (buf, linux_syscall, LINUX_SYSCALL_LEN) == 0)
> - {
> - int syscall =
> - read_register_pid (LINUX_SYSCALL_REGNUM, pid_to_ptid (pid));
> -
> - /* Then check the system call number. */
> - if (syscall == SYS_rt_sigreturn)
> - {
> - CORE_ADDR sp = read_register (SP_REGNUM);
> - CORE_ADDR addr = sp;
> - unsigned long int eflags;
> -
> - addr +=
> - sizeof (struct siginfo) + LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
> -
> - /* Set the trace flag in the context that's about to be
> - restored. */
> - addr += LINUX_SIGCONTEXT_EFLAGS_OFFSET;
> - read_memory (addr, (char *) &eflags, 8);
> - eflags |= 0x0100;
> - write_memory (addr, (char *) &eflags, 8);
> - }
> - }
> - }
> -
> - if (ptrace (request, pid, 0, target_signal_to_host (signal)) == -1)
> - perror_with_name ("ptrace");
> - }
> -
> -
> - /* 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. TARGET is ignored.
> -
> - 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 (CORE_ADDR memaddr, char *myaddr, int len, int write,
> - struct mem_attrib *attrib, struct target_ops *target)
> - {
> - 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. */
> - /* FIXME (alloca): This code, cloned from infptrace.c, is unsafe
> - because it uses alloca to allocate a buffer of arbitrary size.
> - For very large xfers, this could crash GDB's stack. */
> - 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, PIDGET (inferior_ptid),
> - (PTRACE_ARG3_TYPE) addr, 0);
> - }
> -
> - if (count > 1) /* FIXME, avoid if even boundary */
> - {
> - buffer[count - 1] = ptrace (PT_READ_I, PIDGET (inferior_ptid),
> - ((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, PIDGET (inferior_ptid),
> - (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, PIDGET (inferior_ptid),
> - (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, PIDGET (inferior_ptid),
> - (PTRACE_ARG3_TYPE) addr, 0);
> - if (errno)
> - return 0;
> - }
> -
> - /* Copy appropriate bytes out of the buffer. */
> - memcpy (myaddr,
> - (char *) buffer + (memaddr & (sizeof (PTRACE_XFER_TYPE) - 1)),
> - len);
> - }
> - return len;
> - }
> -
> /* Interpreting register set info found in core files. */
> -
> /* Provide registers to GDB from a core file.
>
> CORE_REG_SECT points to an array of bytes, which are the contents
> --- 342,348 ----
> Index: config/i386/nm-x86-64.h
> ===================================================================
> RCS file: /cvs/src/src/gdb/config/i386/nm-x86-64.h,v
> retrieving revision 1.3
> diff -c -3 -p -r1.3 nm-x86-64.h
> *** config/i386/nm-x86-64.h 24 Feb 2002 22:56:05 -0000 1.3
> --- config/i386/nm-x86-64.h 9 Apr 2002 19:52:17 -0000
> *************** extern int kernel_u_size (void);
> *** 65,74 ****
> to get the offset in the core file of the register values. */
> #define KERNEL_U_ADDR 0x0
>
> - /* FIXME use special child_xfer_memory. */
> - #define CHILD_XFER_MEMORY
> -
> #define PTRACE_ARG3_TYPE void*
>
>
> /* We define this if link.h is available, because with ELF we use SVR4 style
> --- 65,72 ----
> to get the offset in the core file of the register values. */
> #define KERNEL_U_ADDR 0x0
>
> #define PTRACE_ARG3_TYPE void*
> + #define PTRACE_XFER_TYPE unsigned long
>
>
> /* We define this if link.h is available, because with ELF we use SVR4 style
> *************** extern int kernel_u_size (void);
> *** 81,89 ****
>
> /* Override copies of {fetch,store}_inferior_registers in `infptrace.c'. */
> #define FETCH_INFERIOR_REGISTERS
> -
> - /* Override child_resume in `infptrace.c'. */
> - #define CHILD_RESUME
>
> #undef PREPARE_TO_PROCEED
>
> --- 79,84 ----