diff options
Diffstat (limited to 'gdb/amd64-linux-tdep.c')
| -rw-r--r-- | gdb/amd64-linux-tdep.c | 148 |
1 files changed, 148 insertions, 0 deletions
diff --git a/gdb/amd64-linux-tdep.c b/gdb/amd64-linux-tdep.c index 5db04c0..b126366 100644 --- a/gdb/amd64-linux-tdep.c +++ b/gdb/amd64-linux-tdep.c @@ -28,6 +28,8 @@ #include "gdbtypes.h" #include "reggroups.h" #include "regset.h" +#include "parser-defs.h" +#include "user-regs.h" #include "amd64-linux-tdep.h" #include "i386-linux-tdep.h" #include "linux-tdep.h" @@ -1643,6 +1645,146 @@ amd64_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, &amd64_linux_xstateregset, "XSAVE extended state", cb_data); } +/* The instruction sequences used in x86_64 machines for a + disabled is-enabled probe. */ + +const gdb_byte amd64_dtrace_disabled_probe_sequence_1[] = { + /* xor %rax, %rax */ 0x48, 0x33, 0xc0, + /* nop */ 0x90, + /* nop */ 0x90 +}; + +const gdb_byte amd64_dtrace_disabled_probe_sequence_2[] = { + /* xor %rax, %rax */ 0x48, 0x33, 0xc0, + /* ret */ 0xc3, + /* nop */ 0x90 +}; + +/* The instruction sequence used in x86_64 machines for enabling a + DTrace is-enabled probe. */ + +const gdb_byte amd64_dtrace_enable_probe_sequence[] = { + /* mov $0x1, %eax */ 0xb8, 0x01, 0x00, 0x00, 0x00 +}; + +/* The instruction sequence used in x86_64 machines for disabling a + DTrace is-enabled probe. */ + +const gdb_byte amd64_dtrace_disable_probe_sequence[] = { + /* xor %rax, %rax; nop; nop */ 0x48, 0x33, 0xC0, 0x90, 0x90 +}; + +/* Implementation of `gdbarch_dtrace_probe_is_enabled', as defined in + gdbarch.h. */ + +static int +amd64_dtrace_probe_is_enabled (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + gdb_byte buf[5]; + + /* This function returns 1 if the instructions at ADDR do _not_ + follow any of the amd64_dtrace_disabled_probe_sequence_* + patterns. + + Note that ADDR is offset 3 bytes from the beginning of these + sequences. */ + + read_code (addr - 3, buf, 5); + return (memcmp (buf, amd64_dtrace_disabled_probe_sequence_1, 5) != 0 + && memcmp (buf, amd64_dtrace_disabled_probe_sequence_2, 5) != 0); +} + +/* Implementation of `gdbarch_dtrace_enable_probe', as defined in + gdbarch.h. */ + +static void +amd64_dtrace_enable_probe (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + /* Note also that ADDR is offset 3 bytes from the beginning of + amd64_dtrace_enable_probe_sequence. */ + + write_memory (addr - 3, amd64_dtrace_enable_probe_sequence, 5); +} + +/* Implementation of `gdbarch_dtrace_disable_probe', as defined in + gdbarch.h. */ + +static void +amd64_dtrace_disable_probe (struct gdbarch *gdbarch, CORE_ADDR addr) +{ + /* Note also that ADDR is offset 3 bytes from the beginning of + amd64_dtrace_disable_probe_sequence. */ + + write_memory (addr - 3, amd64_dtrace_disable_probe_sequence, 5); +} + +/* Implementation of `gdbarch_dtrace_parse_probe_argument', as defined + in gdbarch.h. */ + +static void +amd64_dtrace_parse_probe_argument (struct gdbarch *gdbarch, + struct parser_state *pstate, + int narg) +{ + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + struct frame_info *this_frame = get_selected_frame (NULL); + struct stoken str; + + /* DTrace probe arguments can be found on the ABI-defined places for + regular arguments at the current PC. The probe abstraction + currently supports up to 12 arguments for probes. */ + + if (narg < 6) + { + static const int arg_reg_map[6] = + { + AMD64_RDI_REGNUM, /* Arg 1. */ + AMD64_RSI_REGNUM, /* Arg 2. */ + AMD64_RDX_REGNUM, /* Arg 3. */ + AMD64_RCX_REGNUM, /* Arg 4. */ + AMD64_R8_REGNUM, /* Arg 5. */ + AMD64_R9_REGNUM /* Arg 6. */ + }; + int regno = arg_reg_map[narg]; + const char *regname = user_reg_map_regnum_to_name (gdbarch, regno); + + write_exp_elt_opcode (pstate, OP_REGISTER); + str.ptr = regname; + str.length = strlen (regname); + write_exp_string (pstate, str); + write_exp_elt_opcode (pstate, OP_REGISTER); + } + else + { + /* Additional arguments are passed on the stack. */ + CORE_ADDR sp; + const char *regname = user_reg_map_regnum_to_name (gdbarch, AMD64_RSP_REGNUM); + + /* Displacement. */ + write_exp_elt_opcode (pstate, OP_LONG); + write_exp_elt_type (pstate, builtin_type (gdbarch)->builtin_long); + write_exp_elt_longcst (pstate, narg - 6); + write_exp_elt_opcode (pstate, OP_LONG); + + /* Register: SP. */ + write_exp_elt_opcode (pstate, OP_REGISTER); + str.ptr = regname; + str.length = strlen (regname); + write_exp_string (pstate, str); + write_exp_elt_opcode (pstate, OP_REGISTER); + + write_exp_elt_opcode (pstate, BINOP_ADD); + + /* Cast to long. */ + write_exp_elt_opcode (pstate, UNOP_CAST); + write_exp_elt_type (pstate, + lookup_pointer_type (builtin_type (gdbarch)->builtin_long)); + write_exp_elt_opcode (pstate, UNOP_CAST); + + write_exp_elt_opcode (pstate, UNOP_IND); + } +} + static void amd64_linux_init_abi_common(struct gdbarch_info info, struct gdbarch *gdbarch) { @@ -1907,6 +2049,12 @@ amd64_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) /* GNU/Linux uses SVR4-style shared libraries. */ set_solib_svr4_fetch_link_map_offsets (gdbarch, svr4_lp64_fetch_link_map_offsets); + + /* Register DTrace handlers. */ + set_gdbarch_dtrace_parse_probe_argument (gdbarch, amd64_dtrace_parse_probe_argument); + set_gdbarch_dtrace_probe_is_enabled (gdbarch, amd64_dtrace_probe_is_enabled); + set_gdbarch_dtrace_enable_probe (gdbarch, amd64_dtrace_enable_probe); + set_gdbarch_dtrace_disable_probe (gdbarch, amd64_dtrace_disable_probe); } static void |