diff options
Diffstat (limited to 'gdb/alpha-nbsd-tdep.c')
| -rw-r--r-- | gdb/alpha-nbsd-tdep.c | 304 |
1 files changed, 304 insertions, 0 deletions
diff --git a/gdb/alpha-nbsd-tdep.c b/gdb/alpha-nbsd-tdep.c new file mode 100644 index 0000000..00ff481 --- /dev/null +++ b/gdb/alpha-nbsd-tdep.c @@ -0,0 +1,304 @@ +/* Target-dependent code for NetBSD/alpha. + + Copyright (C) 2002-2016 Free Software Foundation, Inc. + + Contributed by Wasabi Systems, 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 "frame.h" +#include "gdbcore.h" +#include "osabi.h" +#include "regcache.h" +#include "regset.h" +#include "value.h" + +#include "alpha-tdep.h" +#include "alpha-bsd-tdep.h" +#include "nbsd-tdep.h" +#include "solib-svr4.h" +#include "target.h" + +/* Core file support. */ + +/* Even though NetBSD/alpha used ELF since day one, it used the + traditional a.out-style core dump format before NetBSD 1.6. */ + +/* Sizeof `struct reg' in <machine/reg.h>. */ +#define ALPHANBSD_SIZEOF_GREGS (32 * 8) + +/* Sizeof `struct fpreg' in <machine/reg.h. */ +#define ALPHANBSD_SIZEOF_FPREGS ((32 * 8) + 8) + +/* Supply register REGNUM from the buffer specified by FPREGS and LEN + in the floating-point register set REGSET to register cache + REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ + +static void +alphanbsd_supply_fpregset (const struct regset *regset, + struct regcache *regcache, + int regnum, const void *fpregs, size_t len) +{ + const gdb_byte *regs = (const gdb_byte *) fpregs; + int i; + + gdb_assert (len >= ALPHANBSD_SIZEOF_FPREGS); + + for (i = ALPHA_FP0_REGNUM; i < ALPHA_FP0_REGNUM + 31; i++) + { + if (regnum == i || regnum == -1) + regcache_raw_supply (regcache, i, regs + (i - ALPHA_FP0_REGNUM) * 8); + } + + if (regnum == ALPHA_FPCR_REGNUM || regnum == -1) + regcache_raw_supply (regcache, ALPHA_FPCR_REGNUM, regs + 32 * 8); +} + +/* Supply register REGNUM from the buffer specified by GREGS and LEN + in the general-purpose register set REGSET to register cache + REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ + +static void +alphanbsd_aout_supply_gregset (const struct regset *regset, + struct regcache *regcache, + int regnum, const void *gregs, size_t len) +{ + const gdb_byte *regs = (const gdb_byte *) gregs; + int i; + + /* Table to map a GDB register number to a trapframe register index. */ + static const int regmap[] = + { + 0, 1, 2, 3, + 4, 5, 6, 7, + 8, 9, 10, 11, + 12, 13, 14, 15, + 30, 31, 32, 16, + 17, 18, 19, 20, + 21, 22, 23, 24, + 25, 29, 26 + }; + + gdb_assert (len >= ALPHANBSD_SIZEOF_GREGS); + + for (i = 0; i < ARRAY_SIZE(regmap); i++) + { + if (regnum == i || regnum == -1) + regcache_raw_supply (regcache, i, regs + regmap[i] * 8); + } + + if (regnum == ALPHA_PC_REGNUM || regnum == -1) + regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8); + + if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS) + { + regs += ALPHANBSD_SIZEOF_GREGS; + len -= ALPHANBSD_SIZEOF_GREGS; + alphanbsd_supply_fpregset (regset, regcache, regnum, regs, len); + } +} + +/* Supply register REGNUM from the buffer specified by GREGS and LEN + in the general-purpose register set REGSET to register cache + REGCACHE. If REGNUM is -1, do this for all registers in REGSET. */ + +static void +alphanbsd_supply_gregset (const struct regset *regset, + struct regcache *regcache, + int regnum, const void *gregs, size_t len) +{ + const gdb_byte *regs = (const gdb_byte *) gregs; + int i; + + if (len >= ALPHANBSD_SIZEOF_GREGS + ALPHANBSD_SIZEOF_FPREGS) + { + alphanbsd_aout_supply_gregset (regset, regcache, regnum, gregs, len); + return; + } + + for (i = 0; i < ALPHA_ZERO_REGNUM; i++) + { + if (regnum == i || regnum == -1) + regcache_raw_supply (regcache, i, regs + i * 8); + } + + if (regnum == ALPHA_PC_REGNUM || regnum == -1) + regcache_raw_supply (regcache, ALPHA_PC_REGNUM, regs + 31 * 8); +} + +/* NetBSD/alpha register sets. */ + +static const struct regset alphanbsd_gregset = +{ + NULL, + alphanbsd_supply_gregset, + NULL, + REGSET_VARIABLE_SIZE +}; + +static const struct regset alphanbsd_fpregset = +{ + NULL, + alphanbsd_supply_fpregset +}; + +/* Iterate over supported core file register note sections. */ + +void +alphanbsd_iterate_over_regset_sections (struct gdbarch *gdbarch, + iterate_over_regset_sections_cb *cb, + void *cb_data, + const struct regcache *regcache) +{ + cb (".reg", ALPHANBSD_SIZEOF_GREGS, &alphanbsd_gregset, NULL, cb_data); + cb (".reg2", ALPHANBSD_SIZEOF_FPREGS, &alphanbsd_fpregset, NULL, cb_data); +} + + +/* Signal trampolines. */ + +/* Under NetBSD/alpha, signal handler invocations can be identified by the + designated code sequence that is used to return from a signal handler. + In particular, the return address of a signal handler points to the + following code sequence: + + ldq a0, 0(sp) + lda sp, 16(sp) + lda v0, 295(zero) # __sigreturn14 + call_pal callsys + + Each instruction has a unique encoding, so we simply attempt to match + the instruction the PC is pointing to with any of the above instructions. + If there is a hit, we know the offset to the start of the designated + sequence and can then check whether we really are executing in the + signal trampoline. If not, -1 is returned, otherwise the offset from the + start of the return sequence is returned. */ +static const gdb_byte sigtramp_retcode[] = +{ + 0x00, 0x00, 0x1e, 0xa6, /* ldq a0, 0(sp) */ + 0x10, 0x00, 0xde, 0x23, /* lda sp, 16(sp) */ + 0x27, 0x01, 0x1f, 0x20, /* lda v0, 295(zero) */ + 0x83, 0x00, 0x00, 0x00, /* call_pal callsys */ +}; +#define RETCODE_NWORDS 4 +#define RETCODE_SIZE (RETCODE_NWORDS * 4) + +static LONGEST +alphanbsd_sigtramp_offset (struct gdbarch *gdbarch, CORE_ADDR pc) +{ + gdb_byte ret[RETCODE_SIZE], w[4]; + LONGEST off; + int i; + + if (target_read_memory (pc, w, 4) != 0) + return -1; + + for (i = 0; i < RETCODE_NWORDS; i++) + { + if (memcmp (w, sigtramp_retcode + (i * 4), 4) == 0) + break; + } + if (i == RETCODE_NWORDS) + return (-1); + + off = i * 4; + pc -= off; + + if (target_read_memory (pc, ret, sizeof (ret)) != 0) + return -1; + + if (memcmp (ret, sigtramp_retcode, RETCODE_SIZE) == 0) + return off; + + return -1; +} + +static int +alphanbsd_pc_in_sigtramp (struct gdbarch *gdbarch, + CORE_ADDR pc, const char *func_name) +{ + return (nbsd_pc_in_sigtramp (pc, func_name) + || alphanbsd_sigtramp_offset (gdbarch, pc) >= 0); +} + +static CORE_ADDR +alphanbsd_sigcontext_addr (struct frame_info *frame) +{ + /* FIXME: This is not correct for all versions of NetBSD/alpha. + We will probably need to disassemble the trampoline to figure + out which trampoline frame type we have. */ + if (!get_next_frame (frame)) + return 0; + return get_frame_base (get_next_frame (frame)); +} + + +static void +alphanbsd_init_abi (struct gdbarch_info info, + struct gdbarch *gdbarch) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + + /* Hook into the DWARF CFI frame unwinder. */ + alpha_dwarf2_init_abi (info, gdbarch); + + /* Hook into the MDEBUG frame unwinder. */ + alpha_mdebug_init_abi (info, gdbarch); + + /* NetBSD/alpha does not provide single step support via ptrace(2); we + must use software single-stepping. */ + set_gdbarch_software_single_step (gdbarch, alpha_software_single_step); + + /* NetBSD/alpha has SVR4-style shared libraries. */ + set_solib_svr4_fetch_link_map_offsets + (gdbarch, svr4_lp64_fetch_link_map_offsets); + + tdep->dynamic_sigtramp_offset = alphanbsd_sigtramp_offset; + tdep->pc_in_sigtramp = alphanbsd_pc_in_sigtramp; + tdep->sigcontext_addr = alphanbsd_sigcontext_addr; + + tdep->jb_pc = 2; + tdep->jb_elt_size = 8; + + set_gdbarch_iterate_over_regset_sections + (gdbarch, alphanbsd_iterate_over_regset_sections); +} + + +static enum gdb_osabi +alphanbsd_core_osabi_sniffer (bfd *abfd) +{ + if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0) + return GDB_OSABI_NETBSD_ELF; + + return GDB_OSABI_UNKNOWN; +} + + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_alphanbsd_tdep (void); + +void +_initialize_alphanbsd_tdep (void) +{ + /* BFD doesn't set a flavour for NetBSD style a.out core files. */ + gdbarch_register_osabi_sniffer (bfd_arch_alpha, bfd_target_unknown_flavour, + alphanbsd_core_osabi_sniffer); + + gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_NETBSD_ELF, + alphanbsd_init_abi); +} |