/* Target-dependent code for OpenBSD/i386.
Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
- 2003, 2004
+ 2003, 2004, 2005
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"
+#include "bsd-uthread.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 gdb_byte sigreturn[] =
+ {
+ 0xb8,
+ 0x67, 0x00, 0x00, 0x00, /* movl $SYS_sigreturn, %eax */
+ 0xcd, 0x80 /* int $0x80 */
+ };
+ size_t buflen = sizeof sigreturn;
+ gdb_byte *buf;
+ char *name;
+
+ /* 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] =
0 * 4 /* %gs */
};
+/* From /usr/src/lib/libpthread/arch/i386/uthread_machdep.c. */
+static int i386obsd_uthread_reg_offset[] =
+{
+ 11 * 4, /* %eax */
+ 10 * 4, /* %ecx */
+ 9 * 4, /* %edx */
+ 8 * 4, /* %ebx */
+ -1, /* %esp */
+ 6 * 4, /* %ebp */
+ 5 * 4, /* %esi */
+ 4 * 4, /* %edi */
+ 12 * 4, /* %eip */
+ -1, /* %eflags */
+ 13 * 4, /* %cs */
+ -1, /* %ss */
+ 3 * 4, /* %ds */
+ 2 * 4, /* %es */
+ 1 * 4, /* %fs */
+ 0 * 4 /* %gs */
+};
+
+/* Offset within the thread structure where we can find the saved
+ stack pointer (%esp). */
+#define I386OBSD_UTHREAD_ESP_OFFSET 176
+
+static void
+i386obsd_supply_uthread (struct regcache *regcache,
+ int regnum, CORE_ADDR addr)
+{
+ CORE_ADDR sp_addr = addr + I386OBSD_UTHREAD_ESP_OFFSET;
+ CORE_ADDR sp = 0;
+ gdb_byte buf[4];
+ int i;
+
+ gdb_assert (regnum >= -1);
+
+ if (regnum == -1 || regnum == I386_ESP_REGNUM)
+ {
+ int offset;
+
+ /* Fetch stack pointer from thread structure. */
+ sp = read_memory_unsigned_integer (sp_addr, 4);
+
+ /* Adjust the stack pointer such that it looks as if we just
+ returned from _thread_machdep_switch. */
+ offset = i386obsd_uthread_reg_offset[I386_EIP_REGNUM] + 4;
+ store_unsigned_integer (buf, 4, sp + offset);
+ regcache_raw_supply (regcache, I386_ESP_REGNUM, buf);
+ }
+
+ for (i = 0; i < ARRAY_SIZE (i386obsd_uthread_reg_offset); i++)
+ {
+ if (i386obsd_uthread_reg_offset[i] != -1
+ && (regnum == -1 || regnum == i))
+ {
+ /* Fetch stack pointer from thread structure (if we didn't
+ do so already). */
+ if (sp == 0)
+ sp = read_memory_unsigned_integer (sp_addr, 4);
+
+ /* Read the saved register from the stack frame. */
+ read_memory (sp + i386obsd_uthread_reg_offset[i], buf, 4);
+ regcache_raw_supply (regcache, i, buf);
+ }
+ }
+
+}
+
+static void
+i386obsd_collect_uthread (const struct regcache *regcache,
+ int regnum, CORE_ADDR addr)
+{
+ CORE_ADDR sp_addr = addr + I386OBSD_UTHREAD_ESP_OFFSET;
+ CORE_ADDR sp = 0;
+ gdb_byte buf[4];
+ int i;
+
+ gdb_assert (regnum >= -1);
+
+ if (regnum == -1 || regnum == I386_ESP_REGNUM)
+ {
+ int offset;
+
+ /* Calculate the stack pointer (frame pointer) that will be
+ stored into the thread structure. */
+ offset = i386obsd_uthread_reg_offset[I386_EIP_REGNUM] + 4;
+ regcache_raw_collect (regcache, I386_ESP_REGNUM, buf);
+ sp = extract_unsigned_integer (buf, 4) - offset;
+
+ /* Store the stack pointer. */
+ write_memory_unsigned_integer (sp_addr, 4, sp);
+
+ /* The stack pointer was (potentially) modified. Make sure we
+ build a proper stack frame. */
+ regnum = -1;
+ }
+
+ for (i = 0; i < ARRAY_SIZE (i386obsd_uthread_reg_offset); i++)
+ {
+ if (i386obsd_uthread_reg_offset[i] != -1
+ && (regnum == -1 || regnum == i))
+ {
+ /* Fetch stack pointer from thread structure (if we didn't
+ calculate it already). */
+ if (sp == 0)
+ sp = read_memory_unsigned_integer (sp_addr, 4);
+
+ /* Write the register into the stack frame. */
+ regcache_raw_collect (regcache, i, buf);
+ write_memory (sp + i386obsd_uthread_reg_offset[i], buf, 4);
+ }
+ }
+}
+
static void
i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
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 provides a user-level threads implementation. */
+ bsd_uthread_set_supply_uthread (gdbarch, i386obsd_supply_uthread);
+ bsd_uthread_set_collect_uthread (gdbarch, i386obsd_collect_uthread);
}
/* OpenBSD a.out. */
i386_elf_init_abi (info, gdbarch);
/* OpenBSD ELF uses SVR4-style shared libraries. */
- set_gdbarch_in_solib_call_trampoline
- (gdbarch, generic_in_solib_call_trampoline);
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_ilp32_fetch_link_map_offsets);
}
projects / deliverable / binutils-gdb.git / blobdiff