| /* Target-dependent code for SDE on MIPS processors. |
| |
| Copyright (C) 2014-2021 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 "osabi.h" |
| #include "elf-bfd.h" |
| #include "block.h" |
| #include "symtab.h" |
| |
| #include "frame.h" |
| #include "frame-unwind.h" |
| #include "frame-base.h" |
| #include "trad-frame.h" |
| |
| #include "mips-tdep.h" |
| |
| /* Fill in the register cache *THIS_CACHE for THIS_FRAME for use |
| in the SDE frame unwinder. */ |
| |
| static struct trad_frame_cache * |
| mips_sde_frame_cache (struct frame_info *this_frame, void **this_cache) |
| { |
| struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| const struct mips_regnum *regs = mips_regnum (gdbarch); |
| const int sizeof_reg_t = mips_abi_regsize (gdbarch); |
| enum mips_abi abi = mips_abi (gdbarch); |
| struct trad_frame_cache *cache; |
| CORE_ADDR xcpt_frame; |
| CORE_ADDR start_addr; |
| CORE_ADDR stack_addr; |
| CORE_ADDR pc; |
| int i; |
| |
| if (*this_cache != NULL) |
| return (struct trad_frame_cache *) *this_cache; |
| cache = trad_frame_cache_zalloc (this_frame); |
| *this_cache = cache; |
| |
| /* The previous registers are held in struct xcptcontext |
| which is at $sp+offs |
| |
| struct xcptcontext { |
| reg_t sr; CP0 Status |
| reg_t cr; CP0 Cause |
| reg_t epc; CP0 EPC |
| reg_t vaddr; CP0 BadVAddr |
| reg_t regs[32]; General registers |
| reg_t mdlo; LO |
| reg_t mdhi; HI |
| reg_t mdex; ACX |
| ... |
| }; |
| */ |
| |
| stack_addr = get_frame_register_signed (this_frame, |
| gdbarch_sp_regnum (gdbarch)); |
| switch (abi) |
| { |
| case MIPS_ABI_O32: |
| /* 40: XCPTCONTEXT |
| 24: xcpt_gen() argspace (16 bytes) |
| 16: _xcptcall() saved ra, rounded up ( 8 bytes) |
| 00: _xcptcall() argspace (16 bytes) */ |
| xcpt_frame = stack_addr + 40; |
| break; |
| case MIPS_ABI_N32: |
| case MIPS_ABI_N64: |
| default: /* Wild guess. */ |
| /* 16: XCPTCONTEXT |
| 16: xcpt_gen() argspace ( 0 bytes) |
| 00: _xcptcall() saved ra, rounded up (16 bytes) */ |
| xcpt_frame = stack_addr + 16; |
| break; |
| } |
| |
| trad_frame_set_reg_addr (cache, |
| MIPS_PS_REGNUM + gdbarch_num_regs (gdbarch), |
| xcpt_frame + 0 * sizeof_reg_t); |
| trad_frame_set_reg_addr (cache, |
| regs->cause + gdbarch_num_regs (gdbarch), |
| xcpt_frame + 1 * sizeof_reg_t); |
| trad_frame_set_reg_addr (cache, |
| regs->pc + gdbarch_num_regs (gdbarch), |
| xcpt_frame + 2 * sizeof_reg_t); |
| trad_frame_set_reg_addr (cache, |
| regs->badvaddr + gdbarch_num_regs (gdbarch), |
| xcpt_frame + 3 * sizeof_reg_t); |
| for (i = 0; i < MIPS_NUMREGS; i++) |
| trad_frame_set_reg_addr (cache, |
| i + MIPS_ZERO_REGNUM + gdbarch_num_regs (gdbarch), |
| xcpt_frame + (4 + i) * sizeof_reg_t); |
| trad_frame_set_reg_addr (cache, |
| regs->lo + gdbarch_num_regs (gdbarch), |
| xcpt_frame + 36 * sizeof_reg_t); |
| trad_frame_set_reg_addr (cache, |
| regs->hi + gdbarch_num_regs (gdbarch), |
| xcpt_frame + 37 * sizeof_reg_t); |
| |
| pc = get_frame_pc (this_frame); |
| find_pc_partial_function (pc, NULL, &start_addr, NULL); |
| trad_frame_set_id (cache, frame_id_build (start_addr, stack_addr)); |
| |
| return cache; |
| } |
| |
| /* Implement the this_id function for the SDE frame unwinder. */ |
| |
| static void |
| mips_sde_frame_this_id (struct frame_info *this_frame, void **this_cache, |
| struct frame_id *this_id) |
| { |
| struct trad_frame_cache *this_trad_cache |
| = mips_sde_frame_cache (this_frame, this_cache); |
| |
| trad_frame_get_id (this_trad_cache, this_id); |
| } |
| |
| /* Implement the prev_register function for the SDE frame unwinder. */ |
| |
| static struct value * |
| mips_sde_frame_prev_register (struct frame_info *this_frame, |
| void **this_cache, |
| int prev_regnum) |
| { |
| struct trad_frame_cache *trad_cache |
| = mips_sde_frame_cache (this_frame, this_cache); |
| |
| return trad_frame_get_register (trad_cache, this_frame, prev_regnum); |
| } |
| |
| /* Implement the sniffer function for the SDE frame unwinder. */ |
| |
| static int |
| mips_sde_frame_sniffer (const struct frame_unwind *self, |
| struct frame_info *this_frame, |
| void **this_cache) |
| { |
| CORE_ADDR pc = get_frame_pc (this_frame); |
| const char *name; |
| |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| return (name |
| && (strcmp (name, "_xcptcall") == 0 |
| || strcmp (name, "_sigtramp") == 0)); |
| } |
| |
| /* Data structure for the SDE frame unwinder. */ |
| |
| static const struct frame_unwind mips_sde_frame_unwind = |
| { |
| "mips sde sigtramp", |
| SIGTRAMP_FRAME, |
| default_frame_unwind_stop_reason, |
| mips_sde_frame_this_id, |
| mips_sde_frame_prev_register, |
| NULL, |
| mips_sde_frame_sniffer |
| }; |
| |
| /* Implement the this_base, this_locals, and this_args hooks |
| for the normal unwinder. */ |
| |
| static CORE_ADDR |
| mips_sde_frame_base_address (struct frame_info *this_frame, void **this_cache) |
| { |
| struct trad_frame_cache *this_trad_cache |
| = mips_sde_frame_cache (this_frame, this_cache); |
| |
| return trad_frame_get_this_base (this_trad_cache); |
| } |
| |
| static const struct frame_base mips_sde_frame_base = |
| { |
| &mips_sde_frame_unwind, |
| mips_sde_frame_base_address, |
| mips_sde_frame_base_address, |
| mips_sde_frame_base_address |
| }; |
| |
| static const struct frame_base * |
| mips_sde_frame_base_sniffer (struct frame_info *this_frame) |
| { |
| if (mips_sde_frame_sniffer (&mips_sde_frame_unwind, this_frame, NULL)) |
| return &mips_sde_frame_base; |
| else |
| return NULL; |
| } |
| |
| static void |
| mips_sde_elf_osabi_sniff_abi_tag_sections (bfd *abfd, asection *sect, |
| void *obj) |
| { |
| enum gdb_osabi *os_ident_ptr = (enum gdb_osabi *) obj; |
| const char *name; |
| |
| name = bfd_section_name (sect); |
| |
| /* The presence of a section with a ".sde" prefix is indicative |
| of an SDE binary. */ |
| if (startswith (name, ".sde")) |
| *os_ident_ptr = GDB_OSABI_SDE; |
| } |
| |
| /* OSABI sniffer for MIPS SDE. */ |
| |
| static enum gdb_osabi |
| mips_sde_elf_osabi_sniffer (bfd *abfd) |
| { |
| enum gdb_osabi osabi = GDB_OSABI_UNKNOWN; |
| unsigned int elfosabi; |
| |
| /* If the generic sniffer gets a hit, return and let other sniffers |
| get a crack at it. */ |
| for (asection *sect : gdb_bfd_sections (abfd)) |
| generic_elf_osabi_sniff_abi_tag_sections (abfd, sect, &osabi); |
| if (osabi != GDB_OSABI_UNKNOWN) |
| return GDB_OSABI_UNKNOWN; |
| |
| elfosabi = elf_elfheader (abfd)->e_ident[EI_OSABI]; |
| |
| if (elfosabi == ELFOSABI_NONE) |
| { |
| /* When elfosabi is ELFOSABI_NONE (0), then the ELF structures in the |
| file are conforming to the base specification for that machine |
| (there are no OS-specific extensions). In order to determine the |
| real OS in use we must look for OS notes that have been added. |
| |
| For SDE, we simply look for sections named with .sde as prefixes. */ |
| bfd_map_over_sections (abfd, |
| mips_sde_elf_osabi_sniff_abi_tag_sections, |
| &osabi); |
| } |
| return osabi; |
| } |
| |
| static void |
| mips_sde_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| frame_unwind_append_unwinder (gdbarch, &mips_sde_frame_unwind); |
| frame_base_append_sniffer (gdbarch, mips_sde_frame_base_sniffer); |
| } |
| |
| void _initialize_mips_sde_tdep (); |
| void |
| _initialize_mips_sde_tdep () |
| { |
| gdbarch_register_osabi_sniffer (bfd_arch_mips, |
| bfd_target_elf_flavour, |
| mips_sde_elf_osabi_sniffer); |
| |
| gdbarch_register_osabi (bfd_arch_mips, 0, GDB_OSABI_SDE, mips_sde_init_abi); |
| } |