From cfaf379b3a0cd72305e90badeec34ff59dc8b780 Mon Sep 17 00:00:00 2001 From: Mark Kettenis Date: Sun, 21 Aug 2005 15:51:41 +0000 Subject: [PATCH] * vaxobsd-tdep.c: New file. * config/vax/obsd.mt (TDEPFILES): Add vaxobsd-tdep.o. * Makefile.in (vaxobsd-tdep.o): New dependency. --- gdb/ChangeLog | 4 + gdb/Makefile.in | 3 + gdb/config/vax/obsd.mt | 2 +- gdb/vaxobsd-tdep.c | 190 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 198 insertions(+), 1 deletion(-) create mode 100644 gdb/vaxobsd-tdep.c diff --git a/gdb/ChangeLog b/gdb/ChangeLog index af374c94fdf..63c6b954ddb 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,5 +1,9 @@ 2005-08-21 Mark Kettenis + * vaxobsd-tdep.c: New file. + * config/vax/obsd.mt (TDEPFILES): Add vaxobsd-tdep.o. + * Makefile.in (vaxobsd-tdep.o): New dependency. + * ppcobsd-tdep.c: Include "frame.h" and "frame-unwind.h". Don't include "tramp-frame.h". (ppcobsd_sigtramp_cache_init): Remove function. diff --git a/gdb/Makefile.in b/gdb/Makefile.in index 9a46f634ad7..6f86a64f891 100644 --- a/gdb/Makefile.in +++ b/gdb/Makefile.in @@ -2732,6 +2732,9 @@ vax-nat.o: vax-nat.c $(defs_h) $(inferior_h) $(gdb_assert_h) $(vax_tdep_h) \ $(inf_ptrace_h) vaxnbsd-tdep.o: vaxnbsd-tdep.c $(defs_h) $(arch_utils_h) $(osabi_h) \ $(vax_tdep_h) $(solib_svr4_h) $(gdb_string_h) +vaxobsd-tdep.o: vaxobsd-tdep.c $(defs_h) $(arch_utils_h) $(frame_h) \ + $(frame_unwind_h) $(osabi_h) $(symtab_h) $(trad_frame_h) \ + $(vax_tdep_h) $(gdb_string_h) vax-tdep.o: vax-tdep.c $(defs_h) $(arch_utils_h) $(dis_asm_h) $(frame_h) \ $(frame_base_h) $(frame_unwind_h) $(gdbcore_h) $(gdbtypes_h) \ $(osabi_h) $(regcache_h) $(regset_h) $(trad_frame_h) $(value_h) \ diff --git a/gdb/config/vax/obsd.mt b/gdb/config/vax/obsd.mt index c72ef695b11..26cd10cf189 100644 --- a/gdb/config/vax/obsd.mt +++ b/gdb/config/vax/obsd.mt @@ -1,2 +1,2 @@ # Target: OpenBSD/vax -TDEPFILES= vax-tdep.o corelow.o +TDEPFILES= vax-tdep.o vaxobsd-tdep.o corelow.o diff --git a/gdb/vaxobsd-tdep.c b/gdb/vaxobsd-tdep.c new file mode 100644 index 00000000000..41a609db9db --- /dev/null +++ b/gdb/vaxobsd-tdep.c @@ -0,0 +1,190 @@ +/* Target-dependent code for OpenBSD/vax. + + Copyright 2005 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 2 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, write to the Free Software + Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +#include "defs.h" +#include "arch-utils.h" +#include "frame.h" +#include "frame-unwind.h" +#include "osabi.h" +#include "symtab.h" +#include "trad-frame.h" + +#include "vax-tdep.h" + +#include "gdb_string.h" + +/* Signal trampolines. */ + +/* Since OpenBSD 3.2, the sigtramp routine is mapped at a random page + in virtual memory. The randomness makes it somewhat tricky to + detect it, but fortunately we can rely on the fact that the start + of the sigtramp routine is page-aligned. We recognize the + trampoline by looking for the code that invokes the sigreturn + system call. The offset where we can find that code varies from + release to release. + + By the way, the mapping mentioned above is read-only, so you cannot + place a breakpoint in the signal trampoline. */ + +/* Default page size. */ +static const int vaxobsd_page_size = 4096; + +/* Offset for sigreturn(2). */ +static const int vaxobsd_sigreturn_offset = 0x11; + +/* Instruction sequence for sigreturn(2). VAX doesn't have + fixed-length instructions so we include the ensuing exit(2) to + reduce the chance of spurious matches. */ +static const gdb_byte vaxobsd_sigreturn[] = { + 0xbc, 0x8f, 0x67, 0x00, /* chmk $SYS_sigreturn */ + 0xbc, 0x01 /* chmk $SYS_exit */ +}; + +static int +vaxobsd_sigtramp_p (struct frame_info *next_frame) +{ + CORE_ADDR pc = frame_pc_unwind (next_frame); + CORE_ADDR start_pc = (pc & ~(vaxobsd_page_size - 1)); + CORE_ADDR sigreturn_addr = start_pc + vaxobsd_sigreturn_offset; + gdb_byte *buf; + char *name; + + find_pc_partial_function (pc, &name, NULL, NULL); + if (name) + return 0; + + buf = alloca(sizeof vaxobsd_sigreturn); + if (!safe_frame_unwind_memory (next_frame, sigreturn_addr, + buf, sizeof vaxobsd_sigreturn)) + return 0; + + if (memcmp(buf, vaxobsd_sigreturn, sizeof vaxobsd_sigreturn) == 0) + return 1; + + return 0; +} + +static struct trad_frame_cache * +vaxobsd_sigtramp_frame_cache (struct frame_info *next_frame, void **this_cache) +{ + struct trad_frame_cache *cache; + CORE_ADDR addr, base, func; + + if (*this_cache) + return *this_cache; + + cache = trad_frame_cache_zalloc (next_frame); + *this_cache = cache; + + func = frame_pc_unwind (next_frame); + func &= ~(vaxobsd_page_size - 1); + + base = frame_unwind_register_unsigned (next_frame, VAX_SP_REGNUM); + addr = get_frame_memory_unsigned (next_frame, base - 4, 4); + + trad_frame_set_reg_addr (cache, VAX_SP_REGNUM, addr + 8); + trad_frame_set_reg_addr (cache, VAX_FP_REGNUM, addr + 12); + trad_frame_set_reg_addr (cache, VAX_AP_REGNUM, addr + 16); + trad_frame_set_reg_addr (cache, VAX_PC_REGNUM, addr + 20); + trad_frame_set_reg_addr (cache, VAX_PS_REGNUM, addr + 24); + + /* Construct the frame ID using the function start. */ + trad_frame_set_id (cache, frame_id_build (base, func)); + + return cache; +} + +static void +vaxobsd_sigtramp_frame_this_id (struct frame_info *next_frame, + void **this_cache, struct frame_id *this_id) +{ + struct trad_frame_cache *cache = + vaxobsd_sigtramp_frame_cache (next_frame, this_cache); + + trad_frame_get_id (cache, this_id); +} + +static void +vaxobsd_sigtramp_frame_prev_register (struct frame_info *next_frame, + void **this_cache, int regnum, + int *optimizedp, enum lval_type *lvalp, + CORE_ADDR *addrp, int *realnump, + gdb_byte *valuep) +{ + struct trad_frame_cache *cache = + vaxobsd_sigtramp_frame_cache (next_frame, this_cache); + + trad_frame_get_register (cache, next_frame, regnum, + optimizedp, lvalp, addrp, realnump, valuep); +} + +static const struct frame_unwind vaxobsd_sigtramp_frame_unwind = { + SIGTRAMP_FRAME, + vaxobsd_sigtramp_frame_this_id, + vaxobsd_sigtramp_frame_prev_register +}; + +static const struct frame_unwind * +vaxobsd_sigtramp_frame_sniffer (struct frame_info *next_frame) +{ + if (vaxobsd_sigtramp_p (next_frame)) + return &vaxobsd_sigtramp_frame_unwind; + + return NULL; +} + + +/* OpenBSD a.out. */ + +static void +vaxobsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch) +{ + frame_unwind_append_sniffer (gdbarch, vaxobsd_sigtramp_frame_sniffer); +} + +/* FIXME: kettenis/20050821: Since OpenBSD/vax binaries are + indistingushable from NetBSD/vax a.out binaries, building a GDB + that should support both these targets will probably not work as + expected. */ +#define GDB_OSABI_OPENBSD_AOUT GDB_OSABI_NETBSD_AOUT + +static enum gdb_osabi +vaxobsd_aout_osabi_sniffer (bfd *abfd) +{ + if (strcmp (bfd_get_target (abfd), "a.out-vax-netbsd") == 0) + return GDB_OSABI_OPENBSD_AOUT; + + return GDB_OSABI_UNKNOWN; +} + + +/* Provide a prototype to silence -Wmissing-prototypes. */ +void _initialize_vaxobsd_tdep (void); + +void +_initialize_vaxobsd_tdep (void) +{ + gdbarch_register_osabi_sniffer (bfd_arch_vax, bfd_target_aout_flavour, + vaxobsd_aout_osabi_sniffer); + + gdbarch_register_osabi (bfd_arch_vax, 0, GDB_OSABI_OPENBSD_AOUT, + vaxobsd_init_abi); +} -- 2.30.2