/* Target-dependent code for OpenBSD/i386.
- Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002, 2003
+
+ Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
+ 2003, 2004
Free Software Foundation, Inc.
This file is part of GDB.
#include "defs.h"
#include "arch-utils.h"
+#include "frame.h"
#include "gdbcore.h"
#include "regcache.h"
+#include "regset.h"
+#include "symtab.h"
+#include "objfiles.h"
#include "osabi.h"
+#include "target.h"
+
+#include "gdb_assert.h"
+#include "gdb_string.h"
#include "i386-tdep.h"
#include "i387-tdep.h"
+#include "solib-svr4.h"
-/* Provide a prototype to silence -Wmissing-prototypes. */
-void _initialize_i386obsd_tdep (void);
+/* Support for signal handlers. */
-#define SIZEOF_STRUCT_REG (16 * 4)
+/* 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. By the way, the mapping
+ is read-only, so you cannot place a breakpoint in the signal
+ trampoline. */
-static void
-i386obsd_supply_reg (char *regs, int regno)
-{
- int i;
+/* Default page size. */
+static const int i386obsd_page_size = 4096;
- for (i = 0; i <= 15; i++)
- if (regno == i || regno == -1)
- supply_register (i, regs + i * 4);
-}
+/* Return whether the frame preceding NEXT_FRAME corresponds to an
+ OpenBSD sigtramp routine. */
-static void
-fetch_core_registers (char *core_reg_sect, unsigned core_reg_size, int which,
- CORE_ADDR ignore)
+static int
+i386obsd_sigtramp_p (struct frame_info *next_frame)
{
- char *regs, *fsave;
+ CORE_ADDR pc = frame_pc_unwind (next_frame);
+ CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1));
+ const char sigreturn[] =
+ {
+ 0xb8,
+ 0x67, 0x00, 0x00, 0x00, /* movl $SYS_sigreturn, %eax */
+ 0xcd, 0x80 /* int $0x80 */
+ };
+ size_t buflen = sizeof sigreturn;
+ char *name, *buf;
- /* We get everything from one section. */
- if (which != 0)
- return;
+ /* If the function has a valid symbol name, it isn't a
+ trampoline. */
+ find_pc_partial_function (pc, &name, NULL, NULL);
+ if (name != NULL)
+ return 0;
- if (core_reg_size < (SIZEOF_STRUCT_REG + 108))
- {
- warning ("Wrong size register set in core file.");
- return;
- }
+ /* If the function lives in a valid section (even without a starting
+ point) it isn't a trampoline. */
+ if (find_pc_section (pc) != NULL)
+ return 0;
+
+ /* Allocate buffer. */
+ buf = alloca (buflen);
+
+ /* If we can't read the instructions at START_PC, return zero. */
+ if (!safe_frame_unwind_memory (next_frame, start_pc + 0x0a, buf, buflen))
+ return 0;
+
+ /* Check for sigreturn(2). */
+ if (memcmp (buf, sigreturn, buflen) == 0)
+ return 1;
- regs = core_reg_sect;
- fsave = core_reg_sect + SIZEOF_STRUCT_REG;
+ /* If we can't read the instructions at START_PC, return zero. */
+ if (!safe_frame_unwind_memory (next_frame, start_pc + 0x14, buf, buflen))
+ return 0;
- /* Integer registers. */
- i386obsd_supply_reg (regs, -1);
+ /* Check for sigreturn(2) (again). */
+ if (memcmp (buf, sigreturn, buflen) == 0)
+ return 1;
- /* Floating point registers. */
- i387_supply_fsave (fsave, -1);
+ return 0;
}
+\f
+/* Mapping between the general-purpose registers in `struct reg'
+ format and GDB's register cache layout. */
-static struct core_fns i386obsd_core_fns =
+/* From <machine/reg.h>. */
+static int i386obsd_r_reg_offset[] =
{
- bfd_target_unknown_flavour, /* core_flavour */
- default_check_format, /* check_format */
- default_core_sniffer, /* core_sniffer */
- fetch_core_registers, /* core_read_registers */
- NULL /* next */
+ 0 * 4, /* %eax */
+ 1 * 4, /* %ecx */
+ 2 * 4, /* %edx */
+ 3 * 4, /* %ebx */
+ 4 * 4, /* %esp */
+ 5 * 4, /* %ebp */
+ 6 * 4, /* %esi */
+ 7 * 4, /* %edi */
+ 8 * 4, /* %eip */
+ 9 * 4, /* %eflags */
+ 10 * 4, /* %cs */
+ 11 * 4, /* %ss */
+ 12 * 4, /* %ds */
+ 13 * 4, /* %es */
+ 14 * 4, /* %fs */
+ 15 * 4 /* %gs */
};
+
+static void
+i386obsd_aout_supply_regset (const struct regset *regset,
+ struct regcache *regcache, int regnum,
+ const void *regs, size_t len)
+{
+ const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
+
+ gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
+
+ i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
+ i387_supply_fsave (regcache, regnum, (char *) regs + tdep->sizeof_gregset);
+}
+
+static const struct regset *
+i386obsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
+ const char *sect_name,
+ size_t sect_size)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ /* OpenBSD a.out core dumps don't use seperate register sets for the
+ general-purpose and floating-point registers. */
+
+ if (strcmp (sect_name, ".reg") == 0
+ && sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
+ {
+ if (tdep->gregset == NULL)
+ tdep->gregset =
+ regset_alloc (gdbarch, i386obsd_aout_supply_regset, NULL);
+ return tdep->gregset;
+ }
+
+ return NULL;
+}
\f
-CORE_ADDR i386obsd_sigtramp_start = 0xbfbfdf20;
-CORE_ADDR i386obsd_sigtramp_end = 0xbfbfdff0;
+/* Sigtramp routine location for OpenBSD 3.1 and earlier releases. */
+CORE_ADDR i386obsd_sigtramp_start_addr = 0xbfbfdf20;
+CORE_ADDR i386obsd_sigtramp_end_addr = 0xbfbfdff0;
/* From <machine/signal.h>. */
int i386obsd_sc_reg_offset[I386_NUM_GREGS] =
/* Obviously OpenBSD is BSD-based. */
i386bsd_init_abi (info, gdbarch);
+ /* OpenBSD has a different `struct reg'. */
+ tdep->gregset_reg_offset = i386obsd_r_reg_offset;
+ tdep->gregset_num_regs = ARRAY_SIZE (i386obsd_r_reg_offset);
+ tdep->sizeof_gregset = 16 * 4;
+
/* OpenBSD uses -freg-struct-return by default. */
tdep->struct_return = reg_struct_return;
/* OpenBSD uses a different memory layout. */
- tdep->sigtramp_start = i386obsd_sigtramp_start;
- tdep->sigtramp_end = i386obsd_sigtramp_end;
+ tdep->sigtramp_start = i386obsd_sigtramp_start_addr;
+ tdep->sigtramp_end = i386obsd_sigtramp_end_addr;
+ tdep->sigtramp_p = i386obsd_sigtramp_p;
/* OpenBSD has a `struct sigcontext' that's different from the
- origional 4.3 BSD. */
+ original 4.3 BSD. */
tdep->sc_reg_offset = i386obsd_sc_reg_offset;
- tdep->sc_num_regs = I386_NUM_GREGS;
+ tdep->sc_num_regs = ARRAY_SIZE (i386obsd_sc_reg_offset);
}
+/* OpenBSD a.out. */
+
+static void
+i386obsd_aout_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ i386obsd_init_abi (info, gdbarch);
+
+ /* OpenBSD a.out has a single register set. */
+ set_gdbarch_regset_from_core_section
+ (gdbarch, i386obsd_aout_regset_from_core_section);
+}
+
+/* OpenBSD ELF. */
+
+static void
+i386obsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
+
+ /* It's still OpenBSD. */
+ i386obsd_init_abi (info, gdbarch);
+
+ /* But ELF-based. */
+ i386_elf_init_abi (info, gdbarch);
+
+ /* OpenBSD ELF uses SVR4-style shared libraries. */
+ set_solib_svr4_fetch_link_map_offsets
+ (gdbarch, svr4_ilp32_fetch_link_map_offsets);
+}
+\f
+
+/* Provide a prototype to silence -Wmissing-prototypes. */
+void _initialize_i386obsd_tdep (void);
+
void
_initialize_i386obsd_tdep (void)
{
- add_core_fns (&i386obsd_core_fns);
-
/* FIXME: kettenis/20021020: Since OpenBSD/i386 binaries are
indistingushable from NetBSD/i386 a.out binaries, building a GDB
that should support both these targets will probably not work as
#define GDB_OSABI_OPENBSD_AOUT GDB_OSABI_NETBSD_AOUT
gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_OPENBSD_AOUT,
- i386obsd_init_abi);
+ i386obsd_aout_init_abi);
+ gdbarch_register_osabi (bfd_arch_i386, 0, GDB_OSABI_OPENBSD_ELF,
+ i386obsd_elf_init_abi);
}
projects / deliverable / binutils-gdb.git / blobdiff