| /* Target-dependent code for GNU/Linux running on the Fujitsu FR-V, |
| for GDB. |
| |
| Copyright (C) 2004-2021 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 "gdbcore.h" |
| #include "target.h" |
| #include "frame.h" |
| #include "osabi.h" |
| #include "regcache.h" |
| #include "elf-bfd.h" |
| #include "elf/frv.h" |
| #include "frv-tdep.h" |
| #include "trad-frame.h" |
| #include "frame-unwind.h" |
| #include "regset.h" |
| #include "linux-tdep.h" |
| #include "gdbarch.h" |
| |
| /* Define the size (in bytes) of an FR-V instruction. */ |
| static const int frv_instr_size = 4; |
| |
| enum { |
| NORMAL_SIGTRAMP = 1, |
| RT_SIGTRAMP = 2 |
| }; |
| |
| static int |
| frv_linux_pc_in_sigtramp (struct gdbarch *gdbarch, CORE_ADDR pc, |
| const char *name) |
| { |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| gdb_byte buf[frv_instr_size]; |
| LONGEST instr; |
| int retval = 0; |
| |
| if (target_read_memory (pc, buf, sizeof buf) != 0) |
| return 0; |
| |
| instr = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| |
| if (instr == 0x8efc0077) /* setlos #__NR_sigreturn, gr7 */ |
| retval = NORMAL_SIGTRAMP; |
| else if (instr == 0x8efc00ad) /* setlos #__NR_rt_sigreturn, gr7 */ |
| retval = RT_SIGTRAMP; |
| else |
| return 0; |
| |
| if (target_read_memory (pc + frv_instr_size, buf, sizeof buf) != 0) |
| return 0; |
| instr = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| if (instr != 0xc0700000) /* tira gr0, 0 */ |
| return 0; |
| |
| /* If we get this far, we'll return a non-zero value, either |
| NORMAL_SIGTRAMP (1) or RT_SIGTRAMP (2). */ |
| return retval; |
| } |
| |
| /* Given NEXT_FRAME, the "callee" frame of the sigtramp frame that we |
| wish to decode, and REGNO, one of the frv register numbers defined |
| in frv-tdep.h, return the address of the saved register (corresponding |
| to REGNO) in the sigtramp frame. Return -1 if the register is not |
| found in the sigtramp frame. The magic numbers in the code below |
| were computed by examining the following kernel structs: |
| |
| From arch/frv/kernel/signal.c: |
| |
| struct sigframe |
| { |
| void (*pretcode)(void); |
| int sig; |
| struct sigcontext sc; |
| unsigned long extramask[_NSIG_WORDS-1]; |
| uint32_t retcode[2]; |
| }; |
| |
| struct rt_sigframe |
| { |
| void (*pretcode)(void); |
| int sig; |
| struct siginfo *pinfo; |
| void *puc; |
| struct siginfo info; |
| struct ucontext uc; |
| uint32_t retcode[2]; |
| }; |
| |
| From include/asm-frv/ucontext.h: |
| |
| struct ucontext { |
| unsigned long uc_flags; |
| struct ucontext *uc_link; |
| stack_t uc_stack; |
| struct sigcontext uc_mcontext; |
| sigset_t uc_sigmask; |
| }; |
| |
| From include/asm-frv/signal.h: |
| |
| typedef struct sigaltstack { |
| void *ss_sp; |
| int ss_flags; |
| size_t ss_size; |
| } stack_t; |
| |
| From include/asm-frv/sigcontext.h: |
| |
| struct sigcontext { |
| struct user_context sc_context; |
| unsigned long sc_oldmask; |
| } __attribute__((aligned(8))); |
| |
| From include/asm-frv/registers.h: |
| struct user_int_regs |
| { |
| unsigned long psr; |
| unsigned long isr; |
| unsigned long ccr; |
| unsigned long cccr; |
| unsigned long lr; |
| unsigned long lcr; |
| unsigned long pc; |
| unsigned long __status; |
| unsigned long syscallno; |
| unsigned long orig_gr8; |
| unsigned long gner[2]; |
| unsigned long long iacc[1]; |
| |
| union { |
| unsigned long tbr; |
| unsigned long gr[64]; |
| }; |
| }; |
| |
| struct user_fpmedia_regs |
| { |
| unsigned long fr[64]; |
| unsigned long fner[2]; |
| unsigned long msr[2]; |
| unsigned long acc[8]; |
| unsigned char accg[8]; |
| unsigned long fsr[1]; |
| }; |
| |
| struct user_context |
| { |
| struct user_int_regs i; |
| struct user_fpmedia_regs f; |
| |
| void *extension; |
| } __attribute__((aligned(8))); */ |
| |
| static LONGEST |
| frv_linux_sigcontext_reg_addr (struct frame_info *this_frame, int regno, |
| CORE_ADDR *sc_addr_cache_ptr) |
| { |
| struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| CORE_ADDR sc_addr; |
| |
| if (sc_addr_cache_ptr && *sc_addr_cache_ptr) |
| { |
| sc_addr = *sc_addr_cache_ptr; |
| } |
| else |
| { |
| CORE_ADDR pc, sp; |
| gdb_byte buf[4]; |
| int tramp_type; |
| |
| pc = get_frame_pc (this_frame); |
| tramp_type = frv_linux_pc_in_sigtramp (gdbarch, pc, 0); |
| |
| get_frame_register (this_frame, sp_regnum, buf); |
| sp = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| |
| if (tramp_type == NORMAL_SIGTRAMP) |
| { |
| /* For a normal sigtramp frame, the sigcontext struct starts |
| at SP + 8. */ |
| sc_addr = sp + 8; |
| } |
| else if (tramp_type == RT_SIGTRAMP) |
| { |
| /* For a realtime sigtramp frame, SP + 12 contains a pointer |
| to a ucontext struct. The ucontext struct contains a |
| sigcontext struct starting 24 bytes in. (The offset of |
| uc_mcontext within struct ucontext is derived as follows: |
| stack_t is a 12-byte struct and struct sigcontext is |
| 8-byte aligned. This gives an offset of 8 + 12 + 4 (for |
| padding) = 24.) */ |
| if (target_read_memory (sp + 12, buf, sizeof buf) != 0) |
| { |
| warning (_("Can't read realtime sigtramp frame.")); |
| return 0; |
| } |
| sc_addr = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| sc_addr += 24; |
| } |
| else |
| internal_error (__FILE__, __LINE__, _("not a signal trampoline")); |
| |
| if (sc_addr_cache_ptr) |
| *sc_addr_cache_ptr = sc_addr; |
| } |
| |
| switch (regno) |
| { |
| case psr_regnum : |
| return sc_addr + 0; |
| /* sc_addr + 4 has "isr", the Integer Status Register. */ |
| case ccr_regnum : |
| return sc_addr + 8; |
| case cccr_regnum : |
| return sc_addr + 12; |
| case lr_regnum : |
| return sc_addr + 16; |
| case lcr_regnum : |
| return sc_addr + 20; |
| case pc_regnum : |
| return sc_addr + 24; |
| /* sc_addr + 28 is __status, the exception status. |
| sc_addr + 32 is syscallno, the syscall number or -1. |
| sc_addr + 36 is orig_gr8, the original syscall arg #1. |
| sc_addr + 40 is gner[0]. |
| sc_addr + 44 is gner[1]. */ |
| case iacc0h_regnum : |
| return sc_addr + 48; |
| case iacc0l_regnum : |
| return sc_addr + 52; |
| default : |
| if (first_gpr_regnum <= regno && regno <= last_gpr_regnum) |
| return sc_addr + 56 + 4 * (regno - first_gpr_regnum); |
| else if (first_fpr_regnum <= regno && regno <= last_fpr_regnum) |
| return sc_addr + 312 + 4 * (regno - first_fpr_regnum); |
| else |
| return -1; /* not saved. */ |
| } |
| } |
| |
| /* Signal trampolines. */ |
| |
| static struct trad_frame_cache * |
| frv_linux_sigtramp_frame_cache (struct frame_info *this_frame, |
| void **this_cache) |
| { |
| struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| enum bfd_endian byte_order = gdbarch_byte_order (gdbarch); |
| struct trad_frame_cache *cache; |
| CORE_ADDR addr; |
| gdb_byte buf[4]; |
| int regnum; |
| CORE_ADDR sc_addr_cache_val = 0; |
| struct frame_id this_id; |
| |
| 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, sp_regnum, buf); |
| addr = extract_unsigned_integer (buf, sizeof buf, byte_order); |
| this_id = frame_id_build (addr, get_frame_pc (this_frame)); |
| trad_frame_set_id (cache, this_id); |
| |
| for (regnum = 0; regnum < frv_num_regs; regnum++) |
| { |
| LONGEST reg_addr = frv_linux_sigcontext_reg_addr (this_frame, regnum, |
| &sc_addr_cache_val); |
| if (reg_addr != -1) |
| trad_frame_set_reg_addr (cache, regnum, reg_addr); |
| } |
| |
| *this_cache = cache; |
| return cache; |
| } |
| |
| static void |
| frv_linux_sigtramp_frame_this_id (struct frame_info *this_frame, |
| void **this_cache, |
| struct frame_id *this_id) |
| { |
| struct trad_frame_cache *cache |
| = frv_linux_sigtramp_frame_cache (this_frame, this_cache); |
| trad_frame_get_id (cache, this_id); |
| } |
| |
| static struct value * |
| frv_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 |
| = frv_linux_sigtramp_frame_cache (this_frame, this_cache); |
| return trad_frame_get_register (cache, this_frame, regnum); |
| } |
| |
| static int |
| frv_linux_sigtramp_frame_sniffer (const struct frame_unwind *self, |
| struct frame_info *this_frame, |
| void **this_cache) |
| { |
| struct gdbarch *gdbarch = get_frame_arch (this_frame); |
| CORE_ADDR pc = get_frame_pc (this_frame); |
| const char *name; |
| |
| find_pc_partial_function (pc, &name, NULL, NULL); |
| if (frv_linux_pc_in_sigtramp (gdbarch, pc, name)) |
| return 1; |
| |
| return 0; |
| } |
| |
| static const struct frame_unwind frv_linux_sigtramp_frame_unwind = |
| { |
| "frv linux sigtramp", |
| SIGTRAMP_FRAME, |
| default_frame_unwind_stop_reason, |
| frv_linux_sigtramp_frame_this_id, |
| frv_linux_sigtramp_frame_prev_register, |
| NULL, |
| frv_linux_sigtramp_frame_sniffer |
| }; |
| |
| /* The FRV kernel defines ELF_NGREG as 46. We add 2 in order to include |
| the loadmap addresses in the register set. (See below for more info.) */ |
| #define FRV_ELF_NGREG (46 + 2) |
| typedef unsigned char frv_elf_greg_t[4]; |
| typedef struct { frv_elf_greg_t reg[FRV_ELF_NGREG]; } frv_elf_gregset_t; |
| |
| typedef unsigned char frv_elf_fpreg_t[4]; |
| typedef struct |
| { |
| frv_elf_fpreg_t fr[64]; |
| frv_elf_fpreg_t fner[2]; |
| frv_elf_fpreg_t msr[2]; |
| frv_elf_fpreg_t acc[8]; |
| unsigned char accg[8]; |
| frv_elf_fpreg_t fsr[1]; |
| } frv_elf_fpregset_t; |
| |
| /* Register maps. */ |
| |
| static const struct regcache_map_entry frv_linux_gregmap[] = |
| { |
| { 1, psr_regnum, 4 }, |
| { 1, REGCACHE_MAP_SKIP, 4 }, /* isr */ |
| { 1, ccr_regnum, 4 }, |
| { 1, cccr_regnum, 4 }, |
| { 1, lr_regnum, 4 }, |
| { 1, lcr_regnum, 4 }, |
| { 1, pc_regnum, 4 }, |
| { 1, REGCACHE_MAP_SKIP, 4 }, /* __status */ |
| { 1, REGCACHE_MAP_SKIP, 4 }, /* syscallno */ |
| { 1, REGCACHE_MAP_SKIP, 4 }, /* orig_gr8 */ |
| { 1, gner0_regnum, 4 }, |
| { 1, gner1_regnum, 4 }, |
| { 1, REGCACHE_MAP_SKIP, 8 }, /* iacc0 */ |
| { 1, tbr_regnum, 4 }, |
| { 31, first_gpr_regnum + 1, 4 }, /* gr1 ... gr31 */ |
| |
| /* Technically, the loadmap addresses are not part of `pr_reg' as |
| found in the elf_prstatus struct. The fields which communicate |
| the loadmap address appear (by design) immediately after |
| `pr_reg' though, and the BFD function elf32_frv_grok_prstatus() |
| has been implemented to include these fields in the register |
| section that it extracts from the core file. So, for our |
| purposes, they may be viewed as registers. */ |
| |
| { 1, fdpic_loadmap_exec_regnum, 4 }, |
| { 1, fdpic_loadmap_interp_regnum, 4 }, |
| { 0 } |
| }; |
| |
| static const struct regcache_map_entry frv_linux_fpregmap[] = |
| { |
| { 64, first_fpr_regnum, 4 }, /* fr0 ... fr63 */ |
| { 1, fner0_regnum, 4 }, |
| { 1, fner1_regnum, 4 }, |
| { 1, msr0_regnum, 4 }, |
| { 1, msr1_regnum, 4 }, |
| { 8, acc0_regnum, 4 }, /* acc0 ... acc7 */ |
| { 1, accg0123_regnum, 4 }, |
| { 1, accg4567_regnum, 4 }, |
| { 1, fsr0_regnum, 4 }, |
| { 0 } |
| }; |
| |
| /* Unpack an frv_elf_gregset_t into GDB's register cache. */ |
| |
| static void |
| frv_linux_supply_gregset (const struct regset *regset, |
| struct regcache *regcache, |
| int regnum, const void *gregs, size_t len) |
| { |
| int regi; |
| |
| /* gr0 always contains 0. Also, the kernel passes the TBR value in |
| this slot. */ |
| regcache->raw_supply_zeroed (first_gpr_regnum); |
| |
| /* Fill gr32, ..., gr63 with zeros. */ |
| for (regi = first_gpr_regnum + 32; regi <= last_gpr_regnum; regi++) |
| regcache->raw_supply_zeroed (regi); |
| |
| regcache_supply_regset (regset, regcache, regnum, gregs, len); |
| } |
| |
| /* FRV Linux kernel register sets. */ |
| |
| static const struct regset frv_linux_gregset = |
| { |
| frv_linux_gregmap, |
| frv_linux_supply_gregset, regcache_collect_regset |
| }; |
| |
| static const struct regset frv_linux_fpregset = |
| { |
| frv_linux_fpregmap, |
| regcache_supply_regset, regcache_collect_regset |
| }; |
| |
| static void |
| frv_linux_iterate_over_regset_sections (struct gdbarch *gdbarch, |
| iterate_over_regset_sections_cb *cb, |
| void *cb_data, |
| const struct regcache *regcache) |
| { |
| cb (".reg", sizeof (frv_elf_gregset_t), sizeof (frv_elf_gregset_t), |
| &frv_linux_gregset, NULL, cb_data); |
| cb (".reg2", sizeof (frv_elf_fpregset_t), sizeof (frv_elf_fpregset_t), |
| &frv_linux_fpregset, NULL, cb_data); |
| } |
| |
| |
| static void |
| frv_linux_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) |
| { |
| linux_init_abi (info, gdbarch, 0); |
| |
| /* Set the sigtramp frame sniffer. */ |
| frame_unwind_append_unwinder (gdbarch, &frv_linux_sigtramp_frame_unwind); |
| |
| set_gdbarch_iterate_over_regset_sections |
| (gdbarch, frv_linux_iterate_over_regset_sections); |
| } |
| |
| static enum gdb_osabi |
| frv_linux_elf_osabi_sniffer (bfd *abfd) |
| { |
| int elf_flags; |
| |
| elf_flags = elf_elfheader (abfd)->e_flags; |
| |
| /* Assume GNU/Linux if using the FDPIC ABI. If/when another OS shows |
| up that uses this ABI, we'll need to start using .note sections |
| or some such. */ |
| if (elf_flags & EF_FRV_FDPIC) |
| return GDB_OSABI_LINUX; |
| else |
| return GDB_OSABI_UNKNOWN; |
| } |
| |
| void _initialize_frv_linux_tdep (); |
| void |
| _initialize_frv_linux_tdep () |
| { |
| gdbarch_register_osabi (bfd_arch_frv, 0, GDB_OSABI_LINUX, |
| frv_linux_init_abi); |
| gdbarch_register_osabi_sniffer (bfd_arch_frv, |
| bfd_target_elf_flavour, |
| frv_linux_elf_osabi_sniffer); |
| } |