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Diffstat (limited to 'gdb/i386-linux-nat.c')
| -rw-r--r-- | gdb/i386-linux-nat.c | 953 |
1 files changed, 0 insertions, 953 deletions
diff --git a/gdb/i386-linux-nat.c b/gdb/i386-linux-nat.c deleted file mode 100644 index aa2fa6595ab..00000000000 --- a/gdb/i386-linux-nat.c +++ /dev/null @@ -1,953 +0,0 @@ -/* Native-dependent code for Linux/x86. - Copyright 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 "defs.h" -#include "inferior.h" -#include "gdbcore.h" -#include "regcache.h" - -#include "gdb_assert.h" -#include <sys/ptrace.h> -#include <sys/user.h> -#include <sys/procfs.h> - -#ifdef HAVE_SYS_REG_H -#include <sys/reg.h> -#endif - -#ifdef HAVE_SYS_DEBUGREG_H -#include <sys/debugreg.h> -#endif - -#ifndef DR_FIRSTADDR -#define DR_FIRSTADDR 0 -#endif - -#ifndef DR_LASTADDR -#define DR_LASTADDR 3 -#endif - -#ifndef DR_STATUS -#define DR_STATUS 6 -#endif - -#ifndef DR_CONTROL -#define DR_CONTROL 7 -#endif - -/* Prototypes for supply_gregset etc. */ -#include "gregset.h" - -/* Prototypes for i387_supply_fsave etc. */ -#include "i387-nat.h" - -/* Defines for XMM0_REGNUM etc. */ -#include "i386-tdep.h" - -/* Prototypes for local functions. */ -static void dummy_sse_values (void); - - - -/* The register sets used in Linux ELF core-dumps are identical to the - register sets in `struct user' that is used for a.out core-dumps, - and is also used by `ptrace'. The corresponding types are - `elf_gregset_t' for the general-purpose registers (with - `elf_greg_t' the type of a single GP register) and `elf_fpregset_t' - for the floating-point registers. - - Those types used to be available under the names `gregset_t' and - `fpregset_t' too, and this file used those names in the past. But - those names are now used for the register sets used in the - `mcontext_t' type, and have a different size and layout. */ - -/* Mapping between the general-purpose registers in `struct user' - format and GDB's register array layout. */ -static int regmap[] = -{ - EAX, ECX, EDX, EBX, - UESP, EBP, ESI, EDI, - EIP, EFL, CS, SS, - DS, ES, FS, GS -}; - -/* Which ptrace request retrieves which registers? - These apply to the corresponding SET requests as well. */ -#define GETREGS_SUPPLIES(regno) \ - ((0 <= (regno) && (regno) <= 15) || (regno) == I386_LINUX_ORIG_EAX_REGNUM) -#define GETFPREGS_SUPPLIES(regno) \ - (FP0_REGNUM <= (regno) && (regno) <= LAST_FPU_CTRL_REGNUM) -#define GETFPXREGS_SUPPLIES(regno) \ - (FP0_REGNUM <= (regno) && (regno) <= MXCSR_REGNUM) - -/* Does the current host support the GETREGS request? */ -int have_ptrace_getregs = -#ifdef HAVE_PTRACE_GETREGS - 1 -#else - 0 -#endif -; - -/* Does the current host support the GETFPXREGS request? The header - file may or may not define it, and even if it is defined, the - kernel will return EIO if it's running on a pre-SSE processor. - - My instinct is to attach this to some architecture- or - target-specific data structure, but really, a particular GDB - process can only run on top of one kernel at a time. So it's okay - for this to be a simple variable. */ -int have_ptrace_getfpxregs = -#ifdef HAVE_PTRACE_GETFPXREGS - 1 -#else - 0 -#endif -; - - -/* Support for the user struct. */ - -/* Return the address of register REGNUM. BLOCKEND is the value of - u.u_ar0, which should point to the registers. */ - -CORE_ADDR -register_u_addr (CORE_ADDR blockend, int regnum) -{ - return (blockend + 4 * regmap[regnum]); -} - -/* Return the size of the user struct. */ - -int -kernel_u_size (void) -{ - return (sizeof (struct user)); -} - - -/* Fetching registers directly from the U area, one at a time. */ - -/* FIXME: kettenis/2000-03-05: This duplicates code from `inptrace.c'. - The problem is that we define FETCH_INFERIOR_REGISTERS since we - want to use our own versions of {fetch,store}_inferior_registers - that use the GETREGS request. This means that the code in - `infptrace.c' is #ifdef'd out. But we need to fall back on that - code when GDB is running on top of a kernel that doesn't support - the GETREGS request. I want to avoid changing `infptrace.c' right - now. */ - -#ifndef PT_READ_U -#define PT_READ_U PTRACE_PEEKUSR -#endif -#ifndef PT_WRITE_U -#define PT_WRITE_U PTRACE_POKEUSR -#endif - -/* Default the type of the ptrace transfer to int. */ -#ifndef PTRACE_XFER_TYPE -#define PTRACE_XFER_TYPE int -#endif - -/* Registers we shouldn't try to fetch. */ -#define OLD_CANNOT_FETCH_REGISTER(regno) ((regno) >= NUM_GREGS) - -/* Fetch one register. */ - -static void -fetch_register (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]; - int tid; - - if (OLD_CANNOT_FETCH_REGISTER (regno)) - { - memset (buf, '\0', REGISTER_RAW_SIZE (regno)); /* Supply zeroes */ - supply_register (regno, buf); - return; - } - - /* Overload thread id onto process id */ - if ((tid = TIDGET (inferior_ptid)) == 0) - tid = PIDGET (inferior_ptid); /* no thread id, just use process id */ - - 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, tid, - (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 -old_fetch_inferior_registers (int regno) -{ - if (regno >= 0) - { - fetch_register (regno); - } - else - { - for (regno = 0; regno < NUM_REGS; regno++) - { - fetch_register (regno); - } - } -} - -/* Registers we shouldn't try to store. */ -#define OLD_CANNOT_STORE_REGISTER(regno) ((regno) >= NUM_GREGS) - -/* Store one register. */ - -static void -store_register (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. */ - int tid; - - if (OLD_CANNOT_STORE_REGISTER (regno)) - { - return; - } - - /* Overload thread id onto process id */ - if ((tid = TIDGET (inferior_ptid)) == 0) - tid = PIDGET (inferior_ptid); /* no thread id, just use process id */ - - 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, tid, (PTRACE_ARG3_TYPE) regaddr, - *(PTRACE_XFER_TYPE *) & registers[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 -old_store_inferior_registers (int regno) -{ - if (regno >= 0) - { - store_register (regno); - } - else - { - for (regno = 0; regno < NUM_REGS; regno++) - { - store_register (regno); - } - } -} - - -/* Transfering the general-purpose registers between GDB, inferiors - and core files. */ - -/* Fill GDB's register array with the general-purpose register values - in *GREGSETP. */ - -void -supply_gregset (elf_gregset_t *gregsetp) -{ - elf_greg_t *regp = (elf_greg_t *) gregsetp; - int i; - - for (i = 0; i < NUM_GREGS; i++) - supply_register (i, (char *) (regp + regmap[i])); - - supply_register (I386_LINUX_ORIG_EAX_REGNUM, (char *) (regp + ORIG_EAX)); -} - -/* Fill register REGNO (if it is a general-purpose register) in - *GREGSETPS with the value in GDB's register array. If REGNO is -1, - do this for all registers. */ - -void -fill_gregset (elf_gregset_t *gregsetp, int regno) -{ - elf_greg_t *regp = (elf_greg_t *) gregsetp; - int i; - - for (i = 0; i < NUM_GREGS; i++) - if ((regno == -1 || regno == i)) - regcache_collect (i, regp + regmap[i]); - - if (regno == -1 || regno == I386_LINUX_ORIG_EAX_REGNUM) - regcache_collect (I386_LINUX_ORIG_EAX_REGNUM, regp + ORIG_EAX); -} - -#ifdef HAVE_PTRACE_GETREGS - -/* Fetch all general-purpose registers from process/thread TID and - store their values in GDB's register array. */ - -static void -fetch_regs (int tid) -{ - elf_gregset_t regs; - - if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0) - { - if (errno == EIO) - { - /* The kernel we're running on doesn't support the GETREGS - request. Reset `have_ptrace_getregs'. */ - have_ptrace_getregs = 0; - return; - } - - perror_with_name ("Couldn't get registers"); - } - - supply_gregset (®s); -} - -/* Store all valid general-purpose registers in GDB's register array - into the process/thread specified by TID. */ - -static void -store_regs (int tid, int regno) -{ - elf_gregset_t regs; - - if (ptrace (PTRACE_GETREGS, tid, 0, (int) ®s) < 0) - perror_with_name ("Couldn't get registers"); - - fill_gregset (®s, regno); - - if (ptrace (PTRACE_SETREGS, tid, 0, (int) ®s) < 0) - perror_with_name ("Couldn't write registers"); -} - -#else - -static void fetch_regs (int tid) {} -static void store_regs (int tid, int regno) {} - -#endif - - -/* Transfering floating-point registers between GDB, inferiors and cores. */ - -/* Fill GDB's register array with the floating-point register values in - *FPREGSETP. */ - -void -supply_fpregset (elf_fpregset_t *fpregsetp) -{ - i387_supply_fsave ((char *) fpregsetp); - dummy_sse_values (); -} - -/* Fill register REGNO (if it is a floating-point register) in - *FPREGSETP with the value in GDB's register array. If REGNO is -1, - do this for all registers. */ - -void -fill_fpregset (elf_fpregset_t *fpregsetp, int regno) -{ - i387_fill_fsave ((char *) fpregsetp, regno); -} - -#ifdef HAVE_PTRACE_GETREGS - -/* Fetch all floating-point registers from process/thread TID and store - thier values in GDB's register array. */ - -static void -fetch_fpregs (int tid) -{ - elf_fpregset_t fpregs; - - if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0) - perror_with_name ("Couldn't get floating point status"); - - supply_fpregset (&fpregs); -} - -/* Store all valid floating-point registers in GDB's register array - into the process/thread specified by TID. */ - -static void -store_fpregs (int tid, int regno) -{ - elf_fpregset_t fpregs; - - if (ptrace (PTRACE_GETFPREGS, tid, 0, (int) &fpregs) < 0) - perror_with_name ("Couldn't get floating point status"); - - fill_fpregset (&fpregs, regno); - - if (ptrace (PTRACE_SETFPREGS, tid, 0, (int) &fpregs) < 0) - perror_with_name ("Couldn't write floating point status"); -} - -#else - -static void fetch_fpregs (int tid) {} -static void store_fpregs (int tid, int regno) {} - -#endif - - -/* Transfering floating-point and SSE registers to and from GDB. */ - -#ifdef HAVE_PTRACE_GETFPXREGS - -/* Fill GDB's register array with the floating-point and SSE register - values in *FPXREGSETP. */ - -void -supply_fpxregset (elf_fpxregset_t *fpxregsetp) -{ - i387_supply_fxsave ((char *) fpxregsetp); -} - -/* Fill register REGNO (if it is a floating-point or SSE register) in - *FPXREGSETP with the value in GDB's register array. If REGNO is - -1, do this for all registers. */ - -void -fill_fpxregset (elf_fpxregset_t *fpxregsetp, int regno) -{ - i387_fill_fxsave ((char *) fpxregsetp, regno); -} - -/* Fetch all registers covered by the PTRACE_GETFPXREGS request from - process/thread TID and store their values in GDB's register array. - Return non-zero if successful, zero otherwise. */ - -static int -fetch_fpxregs (int tid) -{ - elf_fpxregset_t fpxregs; - - if (! have_ptrace_getfpxregs) - return 0; - - if (ptrace (PTRACE_GETFPXREGS, tid, 0, (int) &fpxregs) < 0) - { - if (errno == EIO) - { - have_ptrace_getfpxregs = 0; - return 0; - } - - perror_with_name ("Couldn't read floating-point and SSE registers"); - } - - supply_fpxregset (&fpxregs); - return 1; -} - -/* Store all valid registers in GDB's register array covered by the - PTRACE_SETFPXREGS request into the process/thread specified by TID. - Return non-zero if successful, zero otherwise. */ - -static int -store_fpxregs (int tid, int regno) -{ - elf_fpxregset_t fpxregs; - - if (! have_ptrace_getfpxregs) - return 0; - - if (ptrace (PTRACE_GETFPXREGS, tid, 0, &fpxregs) == -1) - { - if (errno == EIO) - { - have_ptrace_getfpxregs = 0; - return 0; - } - - perror_with_name ("Couldn't read floating-point and SSE registers"); - } - - fill_fpxregset (&fpxregs, regno); - - if (ptrace (PTRACE_SETFPXREGS, tid, 0, &fpxregs) == -1) - perror_with_name ("Couldn't write floating-point and SSE registers"); - - return 1; -} - -/* Fill the XMM registers in the register array with dummy values. For - cases where we don't have access to the XMM registers. I think - this is cleaner than printing a warning. For a cleaner solution, - we should gdbarchify the i386 family. */ - -static void -dummy_sse_values (void) -{ - /* C doesn't have a syntax for NaN's, so write it out as an array of - longs. */ - static long dummy[4] = { 0xffffffff, 0xffffffff, 0xffffffff, 0xffffffff }; - static long mxcsr = 0x1f80; - int reg; - - for (reg = 0; reg < 8; reg++) - supply_register (XMM0_REGNUM + reg, (char *) dummy); - supply_register (MXCSR_REGNUM, (char *) &mxcsr); -} - -#else - -static int fetch_fpxregs (int tid) { return 0; } -static int store_fpxregs (int tid, int regno) { return 0; } -static void dummy_sse_values (void) {} - -#endif /* HAVE_PTRACE_GETFPXREGS */ - - -/* Transferring arbitrary registers between GDB and inferior. */ - -/* Check if register REGNO in the child process is accessible. - If we are accessing registers directly via the U area, only the - general-purpose registers are available. - All registers should be accessible if we have GETREGS support. */ - -int -cannot_fetch_register (int regno) -{ - if (! have_ptrace_getregs) - return OLD_CANNOT_FETCH_REGISTER (regno); - return 0; -} -int -cannot_store_register (int regno) -{ - if (! have_ptrace_getregs) - return OLD_CANNOT_STORE_REGISTER (regno); - return 0; -} - -/* Fetch register REGNO from the child process. If REGNO is -1, do - this for all registers (including the floating point and SSE - registers). */ - -void -fetch_inferior_registers (int regno) -{ - int tid; - - /* Use the old method of peeking around in `struct user' if the - GETREGS request isn't available. */ - if (! have_ptrace_getregs) - { - old_fetch_inferior_registers (regno); - return; - } - - /* Linux LWP ID's are process ID's. */ - if ((tid = TIDGET (inferior_ptid)) == 0) - tid = PIDGET (inferior_ptid); /* Not a threaded program. */ - - /* Use the PTRACE_GETFPXREGS request whenever possible, since it - transfers more registers in one system call, and we'll cache the - results. But remember that fetch_fpxregs can fail, and return - zero. */ - if (regno == -1) - { - fetch_regs (tid); - - /* The call above might reset `have_ptrace_getregs'. */ - if (! have_ptrace_getregs) - { - old_fetch_inferior_registers (-1); - return; - } - - if (fetch_fpxregs (tid)) - return; - fetch_fpregs (tid); - return; - } - - if (GETREGS_SUPPLIES (regno)) - { - fetch_regs (tid); - return; - } - - if (GETFPXREGS_SUPPLIES (regno)) - { - if (fetch_fpxregs (tid)) - return; - - /* Either our processor or our kernel doesn't support the SSE - registers, so read the FP registers in the traditional way, - and fill the SSE registers with dummy values. It would be - more graceful to handle differences in the register set using - gdbarch. Until then, this will at least make things work - plausibly. */ - fetch_fpregs (tid); - return; - } - - internal_error (__FILE__, __LINE__, - "Got request for bad register number %d.", regno); -} - -/* Store register REGNO back into the child process. If REGNO is -1, - do this for all registers (including the floating point and SSE - registers). */ -void -store_inferior_registers (int regno) -{ - int tid; - - /* Use the old method of poking around in `struct user' if the - SETREGS request isn't available. */ - if (! have_ptrace_getregs) - { - old_store_inferior_registers (regno); - return; - } - - /* Linux LWP ID's are process ID's. */ - if ((tid = TIDGET (inferior_ptid)) == 0) - tid = PIDGET (inferior_ptid); /* Not a threaded program. */ - - /* Use the PTRACE_SETFPXREGS requests whenever possible, since it - transfers more registers in one system call. But remember that - store_fpxregs can fail, and return zero. */ - if (regno == -1) - { - store_regs (tid, regno); - if (store_fpxregs (tid, regno)) - return; - store_fpregs (tid, regno); - return; - } - - if (GETREGS_SUPPLIES (regno)) - { - store_regs (tid, regno); - return; - } - - if (GETFPXREGS_SUPPLIES (regno)) - { - if (store_fpxregs (tid, regno)) - return; - - /* Either our processor or our kernel doesn't support the SSE - registers, so just write the FP registers in the traditional - way. */ - store_fpregs (tid, regno); - return; - } - - internal_error (__FILE__, __LINE__, - "Got request to store bad register number %d.", regno); -} - - -static unsigned long -i386_linux_dr_get (int regnum) -{ - int tid; - unsigned long value; - - /* FIXME: kettenis/2001-01-29: It's not clear what we should do with - multi-threaded processes here. For now, pretend there is just - one thread. */ - tid = PIDGET (inferior_ptid); - - /* FIXME: kettenis/2001-03-27: Calling perror_with_name if the - ptrace call fails breaks debugging remote targets. The correct - way to fix this is to add the hardware breakpoint and watchpoint - stuff to the target vectore. For now, just return zero if the - ptrace call fails. */ - errno = 0; - value = ptrace (PT_READ_U, tid, - offsetof (struct user, u_debugreg[regnum]), 0); - if (errno != 0) -#if 0 - perror_with_name ("Couldn't read debug register"); -#else - return 0; -#endif - - return value; -} - -static void -i386_linux_dr_set (int regnum, unsigned long value) -{ - int tid; - - /* FIXME: kettenis/2001-01-29: It's not clear what we should do with - multi-threaded processes here. For now, pretend there is just - one thread. */ - tid = PIDGET (inferior_ptid); - - errno = 0; - ptrace (PT_WRITE_U, tid, - offsetof (struct user, u_debugreg[regnum]), value); - if (errno != 0) - perror_with_name ("Couldn't write debug register"); -} - -void -i386_linux_dr_set_control (unsigned long control) -{ - i386_linux_dr_set (DR_CONTROL, control); -} - -void -i386_linux_dr_set_addr (int regnum, CORE_ADDR addr) -{ - gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR); - - i386_linux_dr_set (DR_FIRSTADDR + regnum, addr); -} - -void -i386_linux_dr_reset_addr (int regnum) -{ - gdb_assert (regnum >= 0 && regnum <= DR_LASTADDR - DR_FIRSTADDR); - - i386_linux_dr_set (DR_FIRSTADDR + regnum, 0L); -} - -unsigned long -i386_linux_dr_get_status (void) -{ - return i386_linux_dr_get (DR_STATUS); -} - - -/* Interpreting register set info found in core files. */ - -/* Provide registers to GDB from a core file. - - (We can't use the generic version of this function in - core-regset.c, because Linux has *three* different kinds of - register set notes. core-regset.c would have to call - supply_fpxregset, which most platforms don't have.) - - CORE_REG_SECT points to an array of bytes, which are the contents - of a `note' from a core file which BFD thinks might contain - register contents. CORE_REG_SIZE is its size. - - WHICH says which register set corelow suspects this is: - 0 --- the general-purpose register set, in elf_gregset_t format - 2 --- the floating-point register set, in elf_fpregset_t format - 3 --- the extended floating-point register set, in elf_fpxregset_t format - - REG_ADDR isn't used on Linux. */ - -static void -fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, - int which, CORE_ADDR reg_addr) -{ - elf_gregset_t gregset; - elf_fpregset_t fpregset; - - switch (which) - { - case 0: - if (core_reg_size != sizeof (gregset)) - warning ("Wrong size gregset in core file."); - else - { - memcpy (&gregset, core_reg_sect, sizeof (gregset)); - supply_gregset (&gregset); - } - break; - - case 2: - if (core_reg_size != sizeof (fpregset)) - warning ("Wrong size fpregset in core file."); - else - { - memcpy (&fpregset, core_reg_sect, sizeof (fpregset)); - supply_fpregset (&fpregset); - } - break; - -#ifdef HAVE_PTRACE_GETFPXREGS - { - elf_fpxregset_t fpxregset; - - case 3: - if (core_reg_size != sizeof (fpxregset)) - warning ("Wrong size fpxregset in core file."); - else - { - memcpy (&fpxregset, core_reg_sect, sizeof (fpxregset)); - supply_fpxregset (&fpxregset); - } - break; - } -#endif - - default: - /* We've covered all the kinds of registers we know about here, - so this must be something we wouldn't know what to do with - anyway. Just ignore it. */ - break; - } -} - - -/* The instruction for a Linux system call is: - int $0x80 - or 0xcd 0x80. */ - -static const unsigned char linux_syscall[] = { 0xcd, 0x80 }; - -#define LINUX_SYSCALL_LEN (sizeof linux_syscall) - -/* The system call number is stored in the %eax register. */ -#define LINUX_SYSCALL_REGNUM 0 /* %eax */ - -/* We are specifically interested in the sigreturn and rt_sigreturn - system calls. */ - -#ifndef SYS_sigreturn -#define SYS_sigreturn 0x77 -#endif -#ifndef SYS_rt_sigreturn -#define SYS_rt_sigreturn 0xad -#endif - -/* Offset to saved processor flags, from <asm/sigcontext.h>. */ -#define LINUX_SIGCONTEXT_EFLAGS_OFFSET (64) - -/* 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_sigreturn || syscall == SYS_rt_sigreturn) - { - CORE_ADDR sp = read_register (SP_REGNUM); - CORE_ADDR addr = sp; - unsigned long int eflags; - - if (syscall == SYS_rt_sigreturn) - addr = read_memory_integer (sp + 8, 4) + 20; - - /* Set the trace flag in the context that's about to be - restored. */ - addr += LINUX_SIGCONTEXT_EFLAGS_OFFSET; - read_memory (addr, (char *) &eflags, 4); - eflags |= 0x0100; - write_memory (addr, (char *) &eflags, 4); - } - } - } - - if (ptrace (request, pid, 0, target_signal_to_host (signal)) == -1) - perror_with_name ("ptrace"); -} - - -/* Register that we are able to handle Linux ELF core file formats. */ - -static struct core_fns linux_elf_core_fns = -{ - bfd_target_elf_flavour, /* core_flavour */ - default_check_format, /* check_format */ - default_core_sniffer, /* core_sniffer */ - fetch_core_registers, /* core_read_registers */ - NULL /* next */ -}; - -void -_initialize_i386_linux_nat (void) -{ - add_core_fns (&linux_elf_core_fns); -} |