-/* Target-dependent code for Linux running on x86-64, for GDB.
- Copyright 2001
- Free Software Foundation, Inc.
+/* Target-dependent code for GNU/Linux running on x86-64, for GDB.
+
+ Copyright 2001, 2003 Free Software Foundation, Inc.
+
Contributed by Jiri Smid, SuSE Labs.
This file is part of GDB.
#include "inferior.h"
#include "gdbcore.h"
#include "regcache.h"
+#include "osabi.h"
+
+#include "gdb_string.h"
+
#include "x86-64-tdep.h"
-#include "dwarf2cfi.h"
+#include "x86-64-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_DS, USER_ES, USER_FS, USER_GS
+};
+
+/* Fill GDB's register array with the general-purpose register values
+ in *GREGSETP. */
+
+void
+x86_64_linux_supply_gregset (char *regp)
+{
+ int i;
+
+ for (i = 0; i < X86_64_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
+x86_64_linux_fill_gregset (char *regp, int regno)
+{
+ int i;
+
+ for (i = 0; i < X86_64_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
+ x86_64_linux_supply_gregset (core_reg_sect);
+ break;
-#define LINUX_SIGTRAMP_INSN0 (0x48) /* mov $NNNNNNNN,%rax */
-#define LINUX_SIGTRAMP_OFFSET0 (0)
-#define LINUX_SIGTRAMP_INSN1 (0x0f) /* syscall */
-#define LINUX_SIGTRAMP_OFFSET1 (7)
+ 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
+ x86_64_supply_fxsave (current_regcache, -1, core_reg_sect);
+ break;
-static const unsigned char linux_sigtramp_code[] = {
- LINUX_SIGTRAMP_INSN0, 0xc7, 0xc0, 0x89, 0x00, 0x00, 0x00, /* mov $0x89,%rax */
- LINUX_SIGTRAMP_INSN1, 0x05 /* syscall */
+ default:
+ /* Don't know what kind of register request this is; just ignore it. */
+ break;
+ }
+}
+
+static struct core_fns x86_64_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)
x86_64_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;
return pc;
}
-/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
-#define LINUX_UCONTEXT_SIGCONTEXT_OFFSET (36)
+/* Return whether PC is in a GNU/Linux sigtramp routine. */
-/* Assuming FRAME is for a Linux sigtramp routine, return the address
- of the associated sigcontext structure. */
-CORE_ADDR
-x86_64_linux_sigcontext_addr (struct frame_info *frame)
+static int
+x86_64_linux_pc_in_sigtramp (CORE_ADDR pc, char *name)
{
- CORE_ADDR pc;
+ /* 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 (x86_64_linux_sigtramp_start (pc) != 0);
- pc = x86_64_linux_sigtramp_start (frame->pc);
- if (pc)
- {
- if (frame->next)
- /* If this isn't the top frame, the next frame must be for the
- signal handler itself. The sigcontext structure is part of
- the user context. */
- return frame->next->frame + sizeof (struct siginfo) +
- LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
+ return (strcmp ("__restore_rt", name) == 0);
+}
+/* Offset to struct sigcontext in ucontext, from <asm/ucontext.h>. */
+#define X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET 40
- /* This is the top frame. */
- return read_register (SP_REGNUM) + sizeof (struct siginfo) +
- LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
+/* Assuming NEXT_FRAME is a frame following a GNU/Linux sigtramp
+ routine, return the address of the associated sigcontext structure. */
- }
+static CORE_ADDR
+x86_64_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);
- error ("Couldn't recognize signal trampoline.");
- return 0;
+ /* 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 + X86_64_LINUX_UCONTEXT_SIGCONTEXT_OFFSET;
}
+\f
-/* Offset to saved PC in sigcontext, from <asm/sigcontext.h>. */
-#define LINUX_SIGCONTEXT_PC_OFFSET (136)
+/* From <asm/sigcontext.h>. */
+static int x86_64_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 */
+ -1, /* %ds */
+ -1, /* %es */
-/* Assuming FRAME is for a Linux sigtramp routine, return the saved
- program counter. */
+ /* FIXME: kettenis/2002030531: The registers %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, /* %fs */
+ -1 /* %gs */
+};
-CORE_ADDR
-x86_64_linux_sigtramp_saved_pc (struct frame_info *frame)
+static void
+x86_64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
- CORE_ADDR addr;
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+ x86_64_init_abi (info, gdbarch);
+
+ set_gdbarch_pc_in_sigtramp (gdbarch, x86_64_linux_pc_in_sigtramp);
- addr = x86_64_linux_sigcontext_addr (frame);
- return read_memory_integer (addr + LINUX_SIGCONTEXT_PC_OFFSET, 8);
+ tdep->sigcontext_addr = x86_64_linux_sigcontext_addr;
+ tdep->sc_reg_offset = x86_64_linux_sc_reg_offset;
+ tdep->sc_num_regs = ARRAY_SIZE (x86_64_linux_sc_reg_offset);
}
+\f
-/* Immediately after a function call, return the saved pc. */
+/* Provide a prototype to silence -Wmissing-prototypes. */
+extern void _initialize_x86_64_linux_tdep (void);
-CORE_ADDR
-x86_64_linux_saved_pc_after_call (struct frame_info *frame)
+void
+_initialize_x86_64_linux_tdep (void)
{
- if (frame->signal_handler_caller)
- return x86_64_linux_sigtramp_saved_pc (frame);
+ add_core_fns (&x86_64_core_fns);
- return read_memory_integer (read_register (SP_REGNUM), 8);
-}
-
-/* Saved Pc. Get it from sigcontext if within sigtramp. */
-CORE_ADDR
-x86_64_linux_frame_saved_pc (struct frame_info *frame)
-{
- if (frame->signal_handler_caller)
- return x86_64_linux_sigtramp_saved_pc (frame);
- return cfi_get_ra (frame);
+ gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64, GDB_OSABI_LINUX,
+ x86_64_linux_init_abi);
}
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