diff options
Diffstat (limited to 'gdb/m68k-linux-tdep.c')
| -rw-r--r-- | gdb/m68k-linux-tdep.c | 435 |
1 files changed, 435 insertions, 0 deletions
diff --git a/gdb/m68k-linux-tdep.c b/gdb/m68k-linux-tdep.c new file mode 100644 index 0000000..94fb953 --- /dev/null +++ b/gdb/m68k-linux-tdep.c @@ -0,0 +1,435 @@ +/* Motorola m68k target-dependent support for GNU/Linux. + + Copyright (C) 1996-2016 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 3 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, see <http://www.gnu.org/licenses/>. */ + +#include "defs.h" +#include "gdbcore.h" +#include "doublest.h" +#include "floatformat.h" +#include "frame.h" +#include "target.h" +#include "gdbtypes.h" +#include "osabi.h" +#include "regcache.h" +#include "objfiles.h" +#include "symtab.h" +#include "m68k-tdep.h" +#include "trad-frame.h" +#include "frame-unwind.h" +#include "glibc-tdep.h" +#include "solib-svr4.h" +#include "auxv.h" +#include "observer.h" +#include "elf/common.h" +#include "linux-tdep.h" +#include "regset.h" + +/* Offsets (in target ints) into jmp_buf. */ + +#define M68K_LINUX_JB_ELEMENT_SIZE 4 +#define M68K_LINUX_JB_PC 7 + +/* Check whether insn1 and insn2 are parts of a signal trampoline. */ + +#define IS_SIGTRAMP(insn1, insn2) \ + (/* addaw #20,sp; moveq #119,d0; trap #0 */ \ + (insn1 == 0xdefc0014 && insn2 == 0x70774e40) \ + /* moveq #119,d0; trap #0 */ \ + || insn1 == 0x70774e40) + +#define IS_RT_SIGTRAMP(insn1, insn2) \ + (/* movel #173,d0; trap #0 */ \ + (insn1 == 0x203c0000 && insn2 == 0x00ad4e40) \ + /* moveq #82,d0; notb d0; trap #0 */ \ + || (insn1 == 0x70524600 && (insn2 >> 16) == 0x4e40)) + +/* Return non-zero if THIS_FRAME corresponds to a signal trampoline. For + the sake of m68k_linux_get_sigtramp_info we also distinguish between + non-RT and RT signal trampolines. */ + +static int +m68k_linux_pc_in_sigtramp (struct frame_info *this_frame) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + gdb_byte buf[12]; + unsigned long insn0, insn1, insn2; + CORE_ADDR pc = get_frame_pc (this_frame); + + if (!safe_frame_unwind_memory (this_frame, pc - 4, buf, sizeof (buf))) + return 0; + insn1 = extract_unsigned_integer (buf + 4, 4, byte_order); + insn2 = extract_unsigned_integer (buf + 8, 4, byte_order); + if (IS_SIGTRAMP (insn1, insn2)) + return 1; + if (IS_RT_SIGTRAMP (insn1, insn2)) + return 2; + + insn0 = extract_unsigned_integer (buf, 4, byte_order); + if (IS_SIGTRAMP (insn0, insn1)) + return 1; + if (IS_RT_SIGTRAMP (insn0, insn1)) + return 2; + + insn0 = ((insn0 << 16) & 0xffffffff) | (insn1 >> 16); + insn1 = ((insn1 << 16) & 0xffffffff) | (insn2 >> 16); + if (IS_SIGTRAMP (insn0, insn1)) + return 1; + if (IS_RT_SIGTRAMP (insn0, insn1)) + return 2; + + return 0; +} + +/* From <asm/sigcontext.h>. */ +static int m68k_linux_sigcontext_reg_offset[M68K_NUM_REGS] = +{ + 2 * 4, /* %d0 */ + 3 * 4, /* %d1 */ + -1, /* %d2 */ + -1, /* %d3 */ + -1, /* %d4 */ + -1, /* %d5 */ + -1, /* %d6 */ + -1, /* %d7 */ + 4 * 4, /* %a0 */ + 5 * 4, /* %a1 */ + -1, /* %a2 */ + -1, /* %a3 */ + -1, /* %a4 */ + -1, /* %a5 */ + -1, /* %fp */ + 1 * 4, /* %sp */ + 6 * 4, /* %sr */ + 6 * 4 + 2, /* %pc */ + 8 * 4, /* %fp0 */ + 11 * 4, /* %fp1 */ + -1, /* %fp2 */ + -1, /* %fp3 */ + -1, /* %fp4 */ + -1, /* %fp5 */ + -1, /* %fp6 */ + -1, /* %fp7 */ + 14 * 4, /* %fpcr */ + 15 * 4, /* %fpsr */ + 16 * 4 /* %fpiaddr */ +}; + +static int m68k_uclinux_sigcontext_reg_offset[M68K_NUM_REGS] = +{ + 2 * 4, /* %d0 */ + 3 * 4, /* %d1 */ + -1, /* %d2 */ + -1, /* %d3 */ + -1, /* %d4 */ + -1, /* %d5 */ + -1, /* %d6 */ + -1, /* %d7 */ + 4 * 4, /* %a0 */ + 5 * 4, /* %a1 */ + -1, /* %a2 */ + -1, /* %a3 */ + -1, /* %a4 */ + 6 * 4, /* %a5 */ + -1, /* %fp */ + 1 * 4, /* %sp */ + 7 * 4, /* %sr */ + 7 * 4 + 2, /* %pc */ + -1, /* %fp0 */ + -1, /* %fp1 */ + -1, /* %fp2 */ + -1, /* %fp3 */ + -1, /* %fp4 */ + -1, /* %fp5 */ + -1, /* %fp6 */ + -1, /* %fp7 */ + -1, /* %fpcr */ + -1, /* %fpsr */ + -1 /* %fpiaddr */ +}; + +/* From <asm/ucontext.h>. */ +static int m68k_linux_ucontext_reg_offset[M68K_NUM_REGS] = +{ + 6 * 4, /* %d0 */ + 7 * 4, /* %d1 */ + 8 * 4, /* %d2 */ + 9 * 4, /* %d3 */ + 10 * 4, /* %d4 */ + 11 * 4, /* %d5 */ + 12 * 4, /* %d6 */ + 13 * 4, /* %d7 */ + 14 * 4, /* %a0 */ + 15 * 4, /* %a1 */ + 16 * 4, /* %a2 */ + 17 * 4, /* %a3 */ + 18 * 4, /* %a4 */ + 19 * 4, /* %a5 */ + 20 * 4, /* %fp */ + 21 * 4, /* %sp */ + 23 * 4, /* %sr */ + 22 * 4, /* %pc */ + 27 * 4, /* %fp0 */ + 30 * 4, /* %fp1 */ + 33 * 4, /* %fp2 */ + 36 * 4, /* %fp3 */ + 39 * 4, /* %fp4 */ + 42 * 4, /* %fp5 */ + 45 * 4, /* %fp6 */ + 48 * 4, /* %fp7 */ + 24 * 4, /* %fpcr */ + 25 * 4, /* %fpsr */ + 26 * 4 /* %fpiaddr */ +}; + + +/* Get info about saved registers in sigtramp. */ + +struct m68k_linux_sigtramp_info +{ + /* Address of sigcontext. */ + CORE_ADDR sigcontext_addr; + + /* Offset of registers in `struct sigcontext'. */ + int *sc_reg_offset; +}; + +/* Nonzero if running on uClinux. */ +static int target_is_uclinux; + +static void +m68k_linux_inferior_created (struct target_ops *objfile, int from_tty) +{ + /* Record that we will need to re-evaluate whether we are running on a + uClinux or normal GNU/Linux target (see m68k_linux_get_sigtramp_info). */ + target_is_uclinux = -1; +} + +static struct m68k_linux_sigtramp_info +m68k_linux_get_sigtramp_info (struct frame_info *this_frame) +{ + struct gdbarch *gdbarch = get_frame_arch (this_frame); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + CORE_ADDR sp; + struct m68k_linux_sigtramp_info info; + + /* Determine whether we are running on a uClinux or normal GNU/Linux + target so we can use the correct sigcontext layouts. */ + if (target_is_uclinux == -1) + target_is_uclinux = linux_is_uclinux (); + + sp = get_frame_register_unsigned (this_frame, M68K_SP_REGNUM); + + /* Get sigcontext address, it is the third parameter on the stack. */ + info.sigcontext_addr = read_memory_unsigned_integer (sp + 8, 4, byte_order); + + if (m68k_linux_pc_in_sigtramp (this_frame) == 2) + info.sc_reg_offset = m68k_linux_ucontext_reg_offset; + else + info.sc_reg_offset = (target_is_uclinux + ? m68k_uclinux_sigcontext_reg_offset + : m68k_linux_sigcontext_reg_offset); + return info; +} + +/* Signal trampolines. */ + +static struct trad_frame_cache * +m68k_linux_sigtramp_frame_cache (struct frame_info *this_frame, + void **this_cache) +{ + struct frame_id this_id; + struct trad_frame_cache *cache; + struct gdbarch *gdbarch = get_frame_arch (this_frame); + enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); + struct m68k_linux_sigtramp_info info; + gdb_byte buf[4]; + int i; + + if (*this_cache) + return (struct trad_frame_cache *) *this_cache; + + cache = trad_frame_cache_zalloc (this_frame); + + /* FIXME: cagney/2004-05-01: This is is long standing broken code. + The frame ID's code address should be the start-address of the + signal trampoline and not the current PC within that + trampoline. */ + get_frame_register (this_frame, M68K_SP_REGNUM, buf); + /* See the end of m68k_push_dummy_call. */ + this_id = frame_id_build (extract_unsigned_integer (buf, 4, byte_order) + - 4 + 8, get_frame_pc (this_frame)); + trad_frame_set_id (cache, this_id); + + info = m68k_linux_get_sigtramp_info (this_frame); + + for (i = 0; i < M68K_NUM_REGS; i++) + if (info.sc_reg_offset[i] != -1) + trad_frame_set_reg_addr (cache, i, + info.sigcontext_addr + info.sc_reg_offset[i]); + + *this_cache = cache; + return cache; +} + +static void +m68k_linux_sigtramp_frame_this_id (struct frame_info *this_frame, + void **this_cache, + struct frame_id *this_id) +{ + struct trad_frame_cache *cache = + m68k_linux_sigtramp_frame_cache (this_frame, this_cache); + trad_frame_get_id (cache, this_id); +} + +static struct value * +m68k_linux_sigtramp_frame_prev_register (struct frame_info *this_frame, + void **this_cache, + int regnum) +{ + /* Make sure we've initialized the cache. */ + struct trad_frame_cache *cache = + m68k_linux_sigtramp_frame_cache (this_frame, this_cache); + return trad_frame_get_register (cache, this_frame, regnum); +} + +static int +m68k_linux_sigtramp_frame_sniffer (const struct frame_unwind *self, + struct frame_info *this_frame, + void **this_prologue_cache) +{ + return m68k_linux_pc_in_sigtramp (this_frame); +} + +static const struct frame_unwind m68k_linux_sigtramp_frame_unwind = +{ + SIGTRAMP_FRAME, + default_frame_unwind_stop_reason, + m68k_linux_sigtramp_frame_this_id, + m68k_linux_sigtramp_frame_prev_register, + NULL, + m68k_linux_sigtramp_frame_sniffer +}; + +/* Register maps for supply/collect regset functions. */ + +static const struct regcache_map_entry m68k_linux_gregmap[] = + { + { 7, M68K_D1_REGNUM, 4 }, /* d1 ... d7 */ + { 7, M68K_A0_REGNUM, 4 }, /* a0 ... a6 */ + { 1, M68K_D0_REGNUM, 4 }, + { 1, M68K_SP_REGNUM, 4 }, + { 1, REGCACHE_MAP_SKIP, 4 }, /* orig_d0 (skip) */ + { 1, M68K_PS_REGNUM, 4 }, + { 1, M68K_PC_REGNUM, 4 }, + /* Ignore 16-bit fields 'fmtvec' and '__fill'. */ + { 0 } + }; + +#define M68K_LINUX_GREGS_SIZE (20 * 4) + +static const struct regcache_map_entry m68k_linux_fpregmap[] = + { + { 8, M68K_FP0_REGNUM, 12 }, /* fp0 ... fp7 */ + { 1, M68K_FPC_REGNUM, 4 }, + { 1, M68K_FPS_REGNUM, 4 }, + { 1, M68K_FPI_REGNUM, 4 }, + { 0 } + }; + +#define M68K_LINUX_FPREGS_SIZE (27 * 4) + +/* Register sets. */ + +static const struct regset m68k_linux_gregset = + { + m68k_linux_gregmap, + regcache_supply_regset, regcache_collect_regset + }; + +static const struct regset m68k_linux_fpregset = + { + m68k_linux_fpregmap, + regcache_supply_regset, regcache_collect_regset + }; + +/* Iterate over core file register note sections. */ + +static void +m68k_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, + iterate_over_regset_sections_cb *cb, + void *cb_data, + const struct regcache *regcache) +{ + cb (".reg", M68K_LINUX_GREGS_SIZE, &m68k_linux_gregset, NULL, cb_data); + cb (".reg2", M68K_LINUX_FPREGS_SIZE, &m68k_linux_fpregset, NULL, cb_data); +} + +static void +m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + linux_init_abi (info, gdbarch); + + tdep->jb_pc = M68K_LINUX_JB_PC; + tdep->jb_elt_size = M68K_LINUX_JB_ELEMENT_SIZE; + + /* GNU/Linux uses a calling convention that's similar to SVR4. It + returns integer values in %d0/%d1, pointer values in %a0 and + floating values in %fp0, just like SVR4, but uses %a1 to pass the + address to store a structure value. It also returns small + structures in registers instead of memory. */ + m68k_svr4_init_abi (info, gdbarch); + tdep->struct_value_regnum = M68K_A1_REGNUM; + tdep->struct_return = reg_struct_return; + + set_gdbarch_decr_pc_after_break (gdbarch, 2); + + frame_unwind_append_unwinder (gdbarch, &m68k_linux_sigtramp_frame_unwind); + + /* Shared library handling. */ + + /* GNU/Linux uses SVR4-style shared libraries. */ + set_solib_svr4_fetch_link_map_offsets (gdbarch, + svr4_ilp32_fetch_link_map_offsets); + + /* GNU/Linux uses the dynamic linker included in the GNU C Library. */ + set_gdbarch_skip_solib_resolver (gdbarch, glibc_skip_solib_resolver); + + set_gdbarch_skip_trampoline_code (gdbarch, find_solib_trampoline_target); + + /* Core file support. */ + set_gdbarch_iterate_over_regset_sections + (gdbarch, m68k_linux_iterate_over_regset_sections); + + /* Enable TLS support. */ + set_gdbarch_fetch_tls_load_module_address (gdbarch, + svr4_fetch_objfile_link_map); +} + +/* Provide a prototype to silence -Wmissing-prototypes. */ +extern initialize_file_ftype _initialize_m68k_linux_tdep; + +void +_initialize_m68k_linux_tdep (void) +{ + gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX, + m68k_linux_init_abi); + observer_attach_inferior_created (m68k_linux_inferior_created); +} |