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- /* Motorola m68k target-dependent support for GNU/Linux.
- Copyright (C) 1996-2022 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 "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 "observable.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 (inferior *inf)
- {
- /* 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 =
- {
- "m68k linux sigtramp",
- 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_GREGS_SIZE, &m68k_linux_gregset,
- NULL, cb_data);
- cb (".reg2", M68K_LINUX_FPREGS_SIZE, M68K_LINUX_FPREGS_SIZE,
- &m68k_linux_fpregset, NULL, cb_data);
- }
- static void
- m68k_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
- {
- m68k_gdbarch_tdep *tdep = (m68k_gdbarch_tdep *) gdbarch_tdep (gdbarch);
- linux_init_abi (info, gdbarch, 0);
- 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,
- linux_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);
- }
- void _initialize_m68k_linux_tdep ();
- void
- _initialize_m68k_linux_tdep ()
- {
- gdbarch_register_osabi (bfd_arch_m68k, 0, GDB_OSABI_LINUX,
- m68k_linux_init_abi);
- gdb::observers::inferior_created.attach (m68k_linux_inferior_created,
- "m68k-linux-tdep");
- }
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