X-Git-Url: http://git.efficios.com/?a=blobdiff_plain;f=gdb%2Fi386obsd-tdep.c;h=9005304c334ea20345b10439f19731e2f58ed62b;hb=c2d3fccf65e1f765cef27015e13f1b82a395c51e;hp=740bae37456aef9c15a483c9aec7ac7ee80abf89;hpb=aa2a3f87e946fd500d0657c0f3e61f10780b8bfa;p=deliverable%2Fbinutils-gdb.git
diff --git a/gdb/i386obsd-tdep.c b/gdb/i386obsd-tdep.c
index 740bae3745..9005304c33 100644
--- a/gdb/i386obsd-tdep.c
+++ b/gdb/i386obsd-tdep.c
@@ -1,14 +1,13 @@
/* Target-dependent code for OpenBSD/i386.
- Copyright 1988, 1989, 1991, 1992, 1994, 1996, 2000, 2001, 2002,
- 2003, 2004
- Free Software Foundation, Inc.
+ Copyright (C) 1988-1989, 1991-1992, 1994, 1996, 2000-2012 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
+ 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,
@@ -17,17 +16,20 @@
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. */
+ along with this program. If not, see . */
#include "defs.h"
#include "arch-utils.h"
+#include "frame.h"
+#include "frame-unwind.h"
#include "gdbcore.h"
#include "regcache.h"
#include "regset.h"
+#include "symtab.h"
+#include "objfiles.h"
#include "osabi.h"
#include "target.h"
+#include "trad-frame.h"
#include "gdb_assert.h"
#include "gdb_string.h"
@@ -35,77 +37,80 @@
#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. */
+ 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 i386obsd_page_size = 4096;
-/* Return whether PC is in an OpenBSD sigtramp routine. */
+/* Offset for sigreturn(2). */
+static const int i386obsd_sigreturn_offset[] = {
+ 0x0a, /* OpenBSD 3.2 */
+ 0x14, /* OpenBSD 3.6 */
+ 0x3a, /* OpenBSD 3.8 */
+ -1
+};
+
+/* Return whether THIS_FRAME corresponds to an OpenBSD sigtramp
+ routine. */
static int
-i386obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
+i386obsd_sigtramp_p (struct frame_info *this_frame)
{
+ CORE_ADDR pc = get_frame_pc (this_frame);
CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1));
- const char sigreturn[] =
+ /* The call sequence invoking sigreturn(2). */
+ const gdb_byte sigreturn[] =
{
0xb8,
0x67, 0x00, 0x00, 0x00, /* movl $SYS_sigreturn, %eax */
0xcd, 0x80 /* int $0x80 */
};
- char *buf;
-
- /* Avoid reading memory from the target if possible. If we're in a
- named function, we're certainly not in a sigtramp routine
- provided by the kernel. Take synthetic function names into
- account though. */
- if (name && name[0] != '<')
+ size_t buflen = sizeof sigreturn;
+ const int *offset;
+ gdb_byte *buf;
+ const 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 we can't read the instructions at START_PC, return zero. */
- buf = alloca (sizeof sigreturn);
- if (target_read_memory (start_pc + 0x14, buf, sizeof sigreturn))
+ /* 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;
- /* Check for sigreturn(2). */
- if (memcmp (buf, sigreturn, sizeof sigreturn) == 0)
- return 1;
-
- /* Check for a traditional BSD sigtramp routine. */
- return i386bsd_pc_in_sigtramp (pc, name);
-}
-
-/* Return the start address of the sigtramp routine. */
-
-static CORE_ADDR
-i386obsd_sigtramp_start (CORE_ADDR pc)
-{
- CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1));
-
- if (i386bsd_pc_in_sigtramp (pc, NULL))
- return i386bsd_sigtramp_start (pc);
-
- return start_pc;
-}
-
-/* Return the end address of the sigtramp routine. */
-
-static CORE_ADDR
-i386obsd_sigtramp_end (CORE_ADDR pc)
-{
- CORE_ADDR start_pc = (pc & ~(i386obsd_page_size - 1));
+ /* Allocate buffer. */
+ buf = alloca (buflen);
- if (i386bsd_pc_in_sigtramp (pc, NULL))
- return i386bsd_sigtramp_end (pc);
+ /* Loop over all offsets. */
+ for (offset = i386obsd_sigreturn_offset; *offset != -1; offset++)
+ {
+ /* If we can't read the instructions, return zero. */
+ if (!safe_frame_unwind_memory (this_frame, start_pc + *offset,
+ buf, buflen))
+ return 0;
+
+ /* Check for sigreturn(2). */
+ if (memcmp (buf, sigreturn, buflen) == 0)
+ return 1;
+ }
- return start_pc + 0x22;
+ return 0;
}
/* Mapping between the general-purpose registers in `struct reg'
@@ -137,12 +142,13 @@ i386obsd_aout_supply_regset (const struct regset *regset,
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);
+ const gdb_byte *gregs = regs;
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);
+ i387_supply_fsave (regcache, regnum, gregs + tdep->sizeof_gregset);
}
static const struct regset *
@@ -159,11 +165,8 @@ i386obsd_aout_regset_from_core_section (struct gdbarch *gdbarch,
&& 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;
}
@@ -196,6 +199,248 @@ 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)
+{
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ 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, byte_order);
+
+ /* 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, byte_order, 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, byte_order);
+
+ /* 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)
+{
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ 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, byte_order) - offset;
+
+ /* Store the stack pointer. */
+ write_memory_unsigned_integer (sp_addr, 4, byte_order, 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, byte_order);
+
+ /* Write the register into the stack frame. */
+ regcache_raw_collect (regcache, i, buf);
+ write_memory (sp + i386obsd_uthread_reg_offset[i], buf, 4);
+ }
+ }
+}
+
+/* Kernel debugging support. */
+
+/* From . Note that %esp and %ess are only saved in
+ a trap frame when entering the kernel from user space. */
+static int i386obsd_tf_reg_offset[] =
+{
+ 10 * 4, /* %eax */
+ 9 * 4, /* %ecx */
+ 8 * 4, /* %edx */
+ 7 * 4, /* %ebx */
+ -1, /* %esp */
+ 6 * 4, /* %ebp */
+ 5 * 4, /* %esi */
+ 4 * 4, /* %edi */
+ 13 * 4, /* %eip */
+ 15 * 4, /* %eflags */
+ 14 * 4, /* %cs */
+ -1, /* %ss */
+ 3 * 4, /* %ds */
+ 2 * 4, /* %es */
+ 0 * 4, /* %fs */
+ 1 * 4 /* %gs */
+};
+
+static struct trad_frame_cache *
+i386obsd_trapframe_cache (struct frame_info *this_frame, void **this_cache)
+{
+ struct gdbarch *gdbarch = get_frame_arch (this_frame);
+ enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
+ struct trad_frame_cache *cache;
+ CORE_ADDR func, sp, addr;
+ ULONGEST cs;
+ const char *name;
+ int i;
+
+ if (*this_cache)
+ return *this_cache;
+
+ cache = trad_frame_cache_zalloc (this_frame);
+ *this_cache = cache;
+
+ func = get_frame_func (this_frame);
+ sp = get_frame_register_unsigned (this_frame, I386_ESP_REGNUM);
+
+ find_pc_partial_function (func, &name, NULL, NULL);
+ if (name && strncmp (name, "Xintr", 5) == 0)
+ addr = sp + 8; /* It's an interrupt frame. */
+ else
+ addr = sp;
+
+ for (i = 0; i < ARRAY_SIZE (i386obsd_tf_reg_offset); i++)
+ if (i386obsd_tf_reg_offset[i] != -1)
+ trad_frame_set_reg_addr (cache, i, addr + i386obsd_tf_reg_offset[i]);
+
+ /* Read %cs from trap frame. */
+ addr += i386obsd_tf_reg_offset[I386_CS_REGNUM];
+ cs = read_memory_unsigned_integer (addr, 4, byte_order);
+ if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
+ {
+ /* Trap from user space; terminate backtrace. */
+ trad_frame_set_id (cache, outer_frame_id);
+ }
+ else
+ {
+ /* Construct the frame ID using the function start. */
+ trad_frame_set_id (cache, frame_id_build (sp + 8, func));
+ }
+
+ return cache;
+}
+
+static void
+i386obsd_trapframe_this_id (struct frame_info *this_frame,
+ void **this_cache, struct frame_id *this_id)
+{
+ struct trad_frame_cache *cache =
+ i386obsd_trapframe_cache (this_frame, this_cache);
+
+ trad_frame_get_id (cache, this_id);
+}
+
+static struct value *
+i386obsd_trapframe_prev_register (struct frame_info *this_frame,
+ void **this_cache, int regnum)
+{
+ struct trad_frame_cache *cache =
+ i386obsd_trapframe_cache (this_frame, this_cache);
+
+ return trad_frame_get_register (cache, this_frame, regnum);
+}
+
+static int
+i386obsd_trapframe_sniffer (const struct frame_unwind *self,
+ struct frame_info *this_frame,
+ void **this_prologue_cache)
+{
+ ULONGEST cs;
+ const char *name;
+
+ /* Check Current Privilege Level and bail out if we're not executing
+ in kernel space. */
+ cs = get_frame_register_unsigned (this_frame, I386_CS_REGNUM);
+ if ((cs & I386_SEL_RPL) == I386_SEL_UPL)
+ return 0;
+
+ find_pc_partial_function (get_frame_pc (this_frame), &name, NULL, NULL);
+ return (name && (strcmp (name, "calltrap") == 0
+ || strcmp (name, "syscall1") == 0
+ || strncmp (name, "Xintr", 5) == 0
+ || strncmp (name, "Xsoft", 5) == 0));
+}
+
+static const struct frame_unwind i386obsd_trapframe_unwind = {
+ /* FIXME: kettenis/20051219: This really is more like an interrupt
+ frame, but SIGTRAMP_FRAME would print ,
+ which really is not what we want here. */
+ NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
+ i386obsd_trapframe_this_id,
+ i386obsd_trapframe_prev_register,
+ NULL,
+ i386obsd_trapframe_sniffer
+};
+
+
static void
i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
@@ -215,14 +460,19 @@ i386obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
/* OpenBSD uses a different memory layout. */
tdep->sigtramp_start = i386obsd_sigtramp_start_addr;
tdep->sigtramp_end = i386obsd_sigtramp_end_addr;
- set_gdbarch_deprecated_pc_in_sigtramp (gdbarch, i386obsd_pc_in_sigtramp);
- set_gdbarch_deprecated_sigtramp_start (gdbarch, i386obsd_sigtramp_start);
- set_gdbarch_deprecated_sigtramp_end (gdbarch, i386obsd_sigtramp_end);
+ tdep->sigtramp_p = i386obsd_sigtramp_p;
/* OpenBSD has a `struct sigcontext' that's different from the
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);
+
+ /* Unwind kernel trap frames correctly. */
+ frame_unwind_prepend_unwinder (gdbarch, &i386obsd_trapframe_unwind);
}
/* OpenBSD a.out. */
@@ -251,8 +501,6 @@ i386obsd_elf_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
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);
}