diff options
Diffstat (limited to 'gdb/amd64-linux-tdep.c')
| -rw-r--r-- | gdb/amd64-linux-tdep.c | 294 |
1 files changed, 294 insertions, 0 deletions
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c new file mode 100644 index 0000000..9a1636a --- /dev/null +++ b/gdb/amd64-linux-tdep.c @@ -0,0 +1,294 @@ +/* Target-dependent code for GNU/Linux x86-64. + + Copyright 2001, 2003, 2004 Free Software Foundation, Inc. + Contributed by Jiri Smid, SuSE Labs. + + 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 "osabi.h" + +#include "gdb_string.h" + +#include "amd64-tdep.h" +#include "amd64-linux-tdep.h" + +/* Register indexes to 'struct user' come from <sys/reg.h>. */ + +#define USER_R15 0 +#define USER_R14 1 +#define USER_R13 2 +#define USER_R12 3 +#define USER_RBP 4 +#define USER_RBX 5 +#define USER_R11 6 +#define USER_R10 7 +#define USER_R9 8 +#define USER_R8 9 +#define USER_RAX 10 +#define USER_RCX 11 +#define USER_RDX 12 +#define USER_RSI 13 +#define USER_RDI 14 +#define USER_RIP 16 +#define USER_CS 17 +#define USER_EFLAGS 18 +#define USER_RSP 19 +#define USER_SS 20 +#define USER_DS 23 +#define USER_ES 24 +#define USER_FS 25 +#define USER_GS 26 + +/* Mapping between the general-purpose registers in `struct user' + format and GDB's register array layout. */ + +static int user_to_gdb_regmap[] = +{ + USER_RAX, USER_RBX, USER_RCX, USER_RDX, + USER_RSI, USER_RDI, USER_RBP, USER_RSP, + USER_R8, USER_R9, USER_R10, USER_R11, + USER_R12, USER_R13, USER_R14, USER_R15, + USER_RIP, USER_EFLAGS, + USER_CS, USER_SS, + USER_DS, USER_ES, USER_FS, USER_GS +}; + +/* Fill GDB's register array with the general-purpose register values + in *GREGSETP. */ + +void +amd64_linux_supply_gregset (char *regp) +{ + int i; + + for (i = 0; i < AMD64_NUM_GREGS; i++) + supply_register (i, regp + (user_to_gdb_regmap[i] * 8)); +} + +/* 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 +amd64_linux_fill_gregset (char *regp, int regno) +{ + int i; + + for (i = 0; i < AMD64_NUM_GREGS; i++) + if (regno == -1 || regno == i) + regcache_collect (i, regp + (user_to_gdb_regmap[i] * 8)); +} + +/* The register sets used in GNU/Linux ELF core-dumps are identical to + the register sets 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. */ + +static void +fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, + int which, CORE_ADDR ignore) +{ + switch (which) + { + case 0: /* Integer registers. */ + if (core_reg_size != 216) + warning ("Wrong size register set in core file."); + else + amd64_linux_supply_gregset (core_reg_sect); + break; + + case 2: /* Floating point registers. */ + case 3: /* "Extended" floating point registers. This is gdb-speak + for SSE/SSE2. */ + if (core_reg_size != 512) + warning ("Wrong size XMM register set in core file."); + else + amd64_supply_fxsave (current_regcache, -1, core_reg_sect); + break; + + default: + /* Don't know what kind of register request this is; just ignore it. */ + break; + } +} + +static struct core_fns amd64_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 */ +}; + +#define LINUX_SIGTRAMP_INSN0 0x48 /* mov $NNNNNNNN, %rax */ +#define LINUX_SIGTRAMP_OFFSET0 0 +#define LINUX_SIGTRAMP_INSN1 0x0f /* syscall */ +#define LINUX_SIGTRAMP_OFFSET1 7 + +static const unsigned char linux_sigtramp_code[] = +{ + /* mov $__NR_rt_sigreturn, %rax */ + LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x0f, 0x00, 0x00, 0x00, + /* syscall */ + LINUX_SIGTRAMP_INSN1, 0x05 +}; + +#define LINUX_SIGTRAMP_LEN (sizeof linux_sigtramp_code) + +/* If PC is in a sigtramp routine, return the address of the start of + the routine. Otherwise, return 0. */ + +static CORE_ADDR +amd64_linux_sigtramp_start (CORE_ADDR pc) +{ + unsigned char buf[LINUX_SIGTRAMP_LEN]; + + /* We only recognize a signal trampoline if PC is at the start of + one of the two instructions. We optimize for finding the PC at + the start, as will be the case when the trampoline is not the + first frame on the stack. We assume that in the case where the + PC is not at the start of the instruction sequence, there will be + a few trailing readable bytes on the stack. */ + + if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0) + return 0; + + if (buf[0] != LINUX_SIGTRAMP_INSN0) + { + if (buf[0] != LINUX_SIGTRAMP_INSN1) + return 0; + + pc -= LINUX_SIGTRAMP_OFFSET1; + + if (read_memory_nobpt (pc, (char *) buf, LINUX_SIGTRAMP_LEN) != 0) + return 0; + } + + if (memcmp (buf, linux_sigtramp_code, LINUX_SIGTRAMP_LEN) != 0) + return 0; + + return pc; +} + +/* Return whether PC is in a GNU/Linux sigtramp routine. */ + +static int +amd64_linux_pc_in_sigtramp (CORE_ADDR pc, char *name) +{ + /* If we have NAME, we can optimize the search. The trampoline is + named __restore_rt. However, it isn't dynamically exported from + the shared C library, so the trampoline may appear to be part of + the preceding function. This should always be sigaction, + __sigaction, or __libc_sigaction (all aliases to the same + function). */ + if (name == NULL || strstr (name, "sigaction") != NULL) + return (amd64_linux_sigtramp_start (pc) != 0); + + return (strcmp ("__restore_rt", name) == 0); +} + +/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */ +#define AMD64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40 + +/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp + routine, return the address of the associated sigcontext structure. */ + +static CORE_ADDR +amd64_linux_sigcontext_addr (struct frame_info *next_frame) +{ + CORE_ADDR sp; + char buf[8]; + + frame_unwind_register (next_frame, SP_REGNUM, buf); + sp = extract_unsigned_integer (buf, 8); + + /* The sigcontext structure is part of the user context. A pointer + to the user context is passed as the third argument to the signal + handler, i.e. in %rdx. Unfortunately %rdx isn't preserved across + function calls so we can't use it. Fortunately the user context + is part of the signal frame and the unwound %rsp directly points + at it. */ + return sp + AMD64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET; +} + + +/* From <asm/sigcontext.h>. */ +static int amd64_linux_sc_reg_offset[] = +{ + 13 * 8, /* %rax */ + 11 * 8, /* %rbx */ + 14 * 8, /* %rcx */ + 12 * 8, /* %rdx */ + 9 * 8, /* %rsi */ + 8 * 8, /* %rdi */ + 10 * 8, /* %rbp */ + 15 * 8, /* %rsp */ + 0 * 8, /* %r8 */ + 1 * 8, /* %r9 */ + 2 * 8, /* %r10 */ + 3 * 8, /* %r11 */ + 4 * 8, /* %r12 */ + 5 * 8, /* %r13 */ + 6 * 8, /* %r14 */ + 7 * 8, /* %r15 */ + 16 * 8, /* %rip */ + 17 * 8, /* %eflags */ + + /* FIXME: kettenis/2002030531: The registers %cs, %fs and %gs are + available in `struct sigcontext'. However, they only occupy two + bytes instead of four, which makes using them here rather + difficult. Leave them out for now. */ + -1, /* %cs */ + -1, /* %ss */ + -1, /* %ds */ + -1, /* %es */ + -1, /* %fs */ + -1 /* %gs */ +}; + +static void +amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + amd64_init_abi (info, gdbarch); + + set_gdbarch_pc_in_sigtramp (gdbarch, amd64_linux_pc_in_sigtramp); + + tdep->sigcontext_addr = amd64_linux_sigcontext_addr; + tdep->sc_reg_offset = amd64_linux_sc_reg_offset; + tdep->sc_num_regs = ARRAY_SIZE (amd64_linux_sc_reg_offset); +} + + +/* Provide a prototype to silence -Wmissing-prototypes. */ +extern void _initialize_amd64_linux_tdep (void); + +void +_initialize_amd64_linux_tdep (void) +{ + add_core_fns (&amd64_core_fns); + + gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, + GDB_OSABI_LINUX, amd64_linux_init_abi); +} |