/* 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"
+
+/* Support for signal handlers. */
+
+/* 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. */
+
+/* Default page size. */
+static const int i386obsd_page_size = 4096;
+
+/* Return whether the frame preceding NEXT_FRAME corresponds to an
+ OpenBSD sigtramp routine. */
+
+static int
+i386obsd_sigtramp_p (struct frame_info *next_frame)
+{
+ 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;
+
+ /* 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 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;
+
+ /* 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;
+
+ /* Check for sigreturn(2) (again). */
+ if (memcmp (buf, sigreturn, buflen) == 0)
+ return 1;
+
+ return 0;
+}
+\f
+/* Mapping between the general-purpose registers in `struct reg'
+ format and GDB's register cache layout. */
/* From <machine/reg.h>. */
static int i386obsd_r_reg_offset[] =
struct regcache *regcache, int regnum,
const void *regs, size_t len)
{
- const struct gdbarch_tdep *tdep = regset->descr;
+ const struct gdbarch_tdep *tdep = gdbarch_tdep (regset->arch);
gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE);
&& sect_size >= tdep->sizeof_gregset + I387_SIZEOF_FSAVE)
{
if (tdep->gregset == NULL)
- {
- tdep->gregset = XMALLOC (struct regset);
- tdep->gregset->descr = tdep;
- tdep->gregset->supply_regset = i386obsd_aout_supply_regset;
- }
+ tdep->gregset =
+ regset_alloc (gdbarch, i386obsd_aout_supply_regset, NULL);
return tdep->gregset;
}
}
\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] =
tdep->gregset_num_regs = ARRAY_SIZE (i386obsd_r_reg_offset);
tdep->sizeof_gregset = 16 * 4;
- /* OpenBSD has a single register set. */
- set_gdbarch_regset_from_core_section
- (gdbarch, i386obsd_aout_regset_from_core_section);
-
/* 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 = 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. */
#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