/* GNU/Linux on TI C6x target support. Copyright (C) 2011-2018 Free Software Foundation, Inc. Contributed by Yao Qi 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 . */ #include "defs.h" #include "solib.h" #include "osabi.h" #include "linux-tdep.h" #include "tic6x-tdep.h" #include "trad-frame.h" #include "tramp-frame.h" #include "elf-bfd.h" #include "elf/tic6x.h" /* The offset from rt_sigframe pointer to SP register. */ #define TIC6X_SP_RT_SIGFRAME 8 /* Size of struct siginfo info. */ #define TIC6X_SIGINFO_SIZE 128 /* Size of type stack_t, which contains three fields of type void*, int, and size_t respectively. */ #define TIC6X_STACK_T_SIZE (3 * 4) static const gdb_byte tic6x_bkpt_bnop_be[] = { 0x00, 0x00, 0xa1, 0x22 }; static const gdb_byte tic6x_bkpt_bnop_le[] = { 0x22, 0xa1, 0x00, 0x00 }; /* Return the offset of register REGNUM in struct sigcontext. Return 0 if no such register in sigcontext. */ static unsigned int tic6x_register_sigcontext_offset (unsigned int regnum, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); if (regnum == TIC6X_A4_REGNUM || regnum == TIC6X_A4_REGNUM + 2 || regnum == TIC6X_A4_REGNUM + 4) return 4 * (regnum - TIC6X_A4_REGNUM + 2); /* A4, A6, A8 */ else if (regnum == TIC6X_A5_REGNUM || regnum == TIC6X_A5_REGNUM + 2 || regnum == TIC6X_A5_REGNUM + 4) return 4 * (regnum - TIC6X_A5_REGNUM + 12); /* A5, A7, A9 */ else if (regnum == TIC6X_B4_REGNUM || regnum == TIC6X_B4_REGNUM + 2 || regnum == TIC6X_B4_REGNUM + 4) return 4 * (regnum - TIC6X_B4_REGNUM + 3); /* B4, B6, B8 */ else if (regnum == TIC6X_B5_REGNUM || regnum == TIC6X_B5_REGNUM + 2 || regnum == TIC6X_B5_REGNUM + 4) return 4 * (regnum - TIC6X_B5_REGNUM + 19); /* B5, B7, B9 */ else if (regnum < TIC6X_A4_REGNUM) return 4 * (regnum - 0 + 8); /* A0 - A3 */ else if (regnum >= TIC6X_B0_REGNUM && regnum < TIC6X_B4_REGNUM) return 4 * (regnum - TIC6X_B0_REGNUM + 15); /* B0 - B3 */ else if (regnum >= 34 && regnum < 34 + 32) return 4 * (regnum - 34 + 23); /* A16 - A31, B16 - B31 */ else if (regnum == TIC6X_PC_REGNUM) return 4 * (tdep->has_gp ? 55 : 23); else if (regnum == TIC6X_SP_REGNUM) return 4; return 0; } /* Support unwinding frame in signal trampoline. We don't check sigreturn, since it is not used in kernel. */ static void tic6x_linux_rt_sigreturn_init (const struct tramp_frame *self, struct frame_info *this_frame, struct trad_frame_cache *this_cache, CORE_ADDR func) { struct gdbarch *gdbarch = get_frame_arch (this_frame); CORE_ADDR sp = get_frame_register_unsigned (this_frame, TIC6X_SP_REGNUM); /* The base of struct sigcontext is computed by examining the definition of struct rt_sigframe in linux kernel source arch/c6x/kernel/signal.c. */ CORE_ADDR base = (sp + TIC6X_SP_RT_SIGFRAME /* Pointer type *pinfo and *puc in struct rt_sigframe. */ + 4 + 4 + TIC6X_SIGINFO_SIZE + 4 + 4 /* uc_flags and *uc_link in struct ucontext. */ + TIC6X_STACK_T_SIZE); struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); unsigned int reg_offset; unsigned int i; for (i = 0; i < 10; i++) /* A0 - A9 */ { reg_offset = tic6x_register_sigcontext_offset (i, gdbarch); gdb_assert (reg_offset != 0); trad_frame_set_reg_addr (this_cache, i, base + reg_offset); } for (i = TIC6X_B0_REGNUM; i < TIC6X_B0_REGNUM + 10; i++) /* B0 - B9 */ { reg_offset = tic6x_register_sigcontext_offset (i, gdbarch); gdb_assert (reg_offset != 0); trad_frame_set_reg_addr (this_cache, i, base + reg_offset); } if (tdep->has_gp) for (i = 34; i < 34 + 32; i++) /* A16 - A31, B16 - B31 */ { reg_offset = tic6x_register_sigcontext_offset (i, gdbarch); gdb_assert (reg_offset != 0); trad_frame_set_reg_addr (this_cache, i, base + reg_offset); } trad_frame_set_reg_addr (this_cache, TIC6X_PC_REGNUM, base + tic6x_register_sigcontext_offset (TIC6X_PC_REGNUM, gdbarch)); trad_frame_set_reg_addr (this_cache, TIC6X_SP_REGNUM, base + tic6x_register_sigcontext_offset (TIC6X_SP_REGNUM, gdbarch)); /* Save a frame ID. */ trad_frame_set_id (this_cache, frame_id_build (sp, func)); } static struct tramp_frame tic6x_linux_rt_sigreturn_tramp_frame = { SIGTRAMP_FRAME, 4, { {0x000045aa, 0x0fffffff}, /* mvk .S2 139,b0 */ {0x10000000, -1}, /* swe */ {TRAMP_SENTINEL_INSN} }, tic6x_linux_rt_sigreturn_init }; /* When FRAME is at a syscall instruction, return the PC of the next instruction to be executed. */ static CORE_ADDR tic6x_linux_syscall_next_pc (struct frame_info *frame) { ULONGEST syscall_number = get_frame_register_unsigned (frame, TIC6X_B0_REGNUM); CORE_ADDR pc = get_frame_pc (frame); if (syscall_number == 139 /* rt_sigreturn */) return frame_unwind_caller_pc (frame); return pc + 4; } extern struct target_so_ops dsbt_so_ops; static void tic6x_uclinux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); linux_init_abi (info, gdbarch); /* Shared library handling. */ set_solib_ops (gdbarch, &dsbt_so_ops); tdep->syscall_next_pc = tic6x_linux_syscall_next_pc; #ifdef HAVE_ELF /* In tic6x Linux kernel, breakpoint instructions varies on different archs. On C64x+ and C67x+, breakpoint instruction is 0x56454314, which is an illegal opcode. On other arch, breakpoint instruction is 0x0000a122 (BNOP .S2 0,5). */ if (info.abfd) switch (bfd_elf_get_obj_attr_int (info.abfd, OBJ_ATTR_PROC, Tag_ISA)) { case C6XABI_Tag_ISA_C64XP: case C6XABI_Tag_ISA_C67XP: if (info.byte_order == BFD_ENDIAN_BIG) tdep->breakpoint = tic6x_bkpt_illegal_opcode_be; else tdep->breakpoint = tic6x_bkpt_illegal_opcode_le; break; default: { if (info.byte_order == BFD_ENDIAN_BIG) tdep->breakpoint = tic6x_bkpt_bnop_be; else tdep->breakpoint = tic6x_bkpt_bnop_le; } } #endif /* Signal trampoline support. */ tramp_frame_prepend_unwinder (gdbarch, &tic6x_linux_rt_sigreturn_tramp_frame); } void _initialize_tic6x_linux_tdep (void) { gdbarch_register_osabi (bfd_arch_tic6x, 0, GDB_OSABI_LINUX, tic6x_uclinux_init_abi); }