/* Target-dependent code for OpenBSD/amd64.
- Copyright 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2003-2015 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,
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 <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "frame.h"
+#include "frame-unwind.h"
#include "gdbcore.h"
+#include "symtab.h"
+#include "objfiles.h"
#include "osabi.h"
+#include "regcache.h"
#include "regset.h"
#include "target.h"
+#include "trad-frame.h"
-#include "gdb_assert.h"
-#include "gdb_string.h"
-
-#include "x86-64-tdep.h"
+#include "obsd-tdep.h"
+#include "amd64-tdep.h"
#include "i387-tdep.h"
#include "solib-svr4.h"
+#include "bsd-uthread.h"
/* Support for core dumps. */
struct regcache *regcache, int regnum,
const void *regs, size_t len)
{
- const struct gdbarch_tdep *tdep = regset->descr;
+ struct gdbarch *gdbarch = get_regcache_arch (regcache);
+ const struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
gdb_assert (len >= tdep->sizeof_gregset + I387_SIZEOF_FXSAVE);
i386_supply_gregset (regset, regcache, regnum, regs, tdep->sizeof_gregset);
- amd64_supply_fxsave (regcache, regnum, (char *)regs + tdep->sizeof_gregset);
+ amd64_supply_fxsave (regcache, regnum,
+ ((const gdb_byte *)regs) + tdep->sizeof_gregset);
}
-static const struct regset *
-amd64obsd_regset_from_core_section (struct gdbarch *gdbarch,
- const char *sect_name, size_t sect_size)
+static const struct regset amd64obsd_combined_regset =
+ {
+ NULL, amd64obsd_supply_regset, NULL
+ };
+
+static void
+amd64obsd_iterate_over_regset_sections (struct gdbarch *gdbarch,
+ iterate_over_regset_sections_cb *cb,
+ void *cb_data,
+ const struct regcache *regcache)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
/* OpenBSD 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_FXSAVE)
- {
- if (tdep->gregset == NULL)
- {
- tdep->gregset = XMALLOC (struct regset);
- tdep->gregset->descr = tdep;
- tdep->gregset->supply_regset = amd64obsd_supply_regset;
- }
- return tdep->gregset;
- }
-
- return NULL;
+ cb (".reg", tdep->sizeof_gregset + I387_SIZEOF_FXSAVE,
+ &amd64obsd_combined_regset, NULL, cb_data);
}
\f
/* Support for signal handlers. */
+/* Default page size. */
static const int amd64obsd_page_size = 4096;
+/* Return whether THIS_FRAME corresponds to an OpenBSD sigtramp
+ routine. */
+
static int
-amd64obsd_pc_in_sigtramp (CORE_ADDR pc, char *name)
+amd64obsd_sigtramp_p (struct frame_info *this_frame)
{
+ CORE_ADDR pc = get_frame_pc (this_frame);
CORE_ADDR start_pc = (pc & ~(amd64obsd_page_size - 1));
- const char sigreturn[] =
+ const gdb_byte osigreturn[] =
{
0x48, 0xc7, 0xc0,
0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
0xcd, 0x80 /* int $0x80 */
};
- char *buf;
+ const gdb_byte sigreturn[] =
+ {
+ 0x48, 0xc7, 0xc0,
+ 0x67, 0x00, 0x00, 0x00, /* movq $SYS_sigreturn, %rax */
+ 0x0f, 0x05 /* syscall */
+ };
+ size_t buflen = (sizeof sigreturn) + 1;
+ 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 (name)
+ /* 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;
/* If we can't read the instructions at START_PC, return zero. */
- buf = alloca (sizeof sigreturn);
- if (target_read_memory (start_pc + 0x7, buf, sizeof sigreturn))
+ buf = alloca ((sizeof sigreturn) + 1);
+ if (!safe_frame_unwind_memory (this_frame, start_pc + 6, buf, buflen))
return 0;
- /* Check for sigreturn(2). */
- if (memcmp (buf, sigreturn, sizeof sigreturn))
+ /* Check for sigreturn(2). Depending on how the assembler encoded
+ the `movq %rsp, %rdi' instruction, the code starts at offset 6 or
+ 7. OpenBSD 5.0 and later use the `syscall' instruction. Older
+ versions use `int $0x80'. Check for both. */
+ if (memcmp (buf, sigreturn, sizeof sigreturn)
+ && memcmp (buf + 1, sigreturn, sizeof sigreturn)
+ && memcmp (buf, osigreturn, sizeof osigreturn)
+ && memcmp (buf + 1, osigreturn, sizeof osigreturn))
return 0;
return 1;
}
-/* Assuming NEXT_FRAME is for a frame following a BSD sigtramp
- routine, return the address of the associated sigcontext structure. */
+/* Assuming THIS_FRAME is for a BSD sigtramp routine, return the
+ address of the associated sigcontext structure. */
static CORE_ADDR
-amd64obsd_sigcontext_addr (struct frame_info *next_frame)
+amd64obsd_sigcontext_addr (struct frame_info *this_frame)
{
+ CORE_ADDR pc = get_frame_pc (this_frame);
+ ULONGEST offset = (pc & (amd64obsd_page_size - 1));
+
/* The %rsp register points at `struct sigcontext' upon entry of a
- signal trampoline. */
- return frame_unwind_register_unsigned (next_frame, AMD64_RSP_REGNUM);
+ signal trampoline. The relevant part of the trampoline is
+
+ call *%rax
+ movq %rsp, %rdi
+ pushq %rdi
+ movq $SYS_sigreturn,%rax
+ int $0x80
+
+ (see /usr/src/sys/arch/amd64/amd64/locore.S). The `pushq'
+ instruction clobbers %rsp, but its value is saved in `%rdi'. */
+
+ if (offset > 5)
+ return get_frame_register_unsigned (this_frame, AMD64_RDI_REGNUM);
+ else
+ return get_frame_register_unsigned (this_frame, AMD64_RSP_REGNUM);
}
\f
/* OpenBSD 3.5 or later. */
0 * 8, /* %rdi */
12 * 8, /* %rbp */
15 * 8, /* %rsp */
- 4 * 8, /* %r8 .. */
+ 4 * 8, /* %r8 .. */
5 * 8,
6 * 8,
7 * 8,
0 * 8, /* %rdi */
12 * 8, /* %rbp */
24 * 8, /* %rsp */
- 4 * 8, /* %r8 ... */
+ 4 * 8, /* %r8 ... */
5 * 8,
6 * 8,
7 * 8,
15 * 8 /* %gs */
};
+/* From /usr/src/lib/libpthread/arch/amd64/uthread_machdep.c. */
+static int amd64obsd_uthread_reg_offset[] =
+{
+ 19 * 8, /* %rax */
+ 16 * 8, /* %rbx */
+ 18 * 8, /* %rcx */
+ 17 * 8, /* %rdx */
+ 14 * 8, /* %rsi */
+ 13 * 8, /* %rdi */
+ 15 * 8, /* %rbp */
+ -1, /* %rsp */
+ 12 * 8, /* %r8 ... */
+ 11 * 8,
+ 10 * 8,
+ 9 * 8,
+ 8 * 8,
+ 7 * 8,
+ 6 * 8,
+ 5 * 8, /* ... %r15 */
+ 20 * 8, /* %rip */
+ 4 * 8, /* %eflags */
+ 21 * 8, /* %cs */
+ -1, /* %ss */
+ 3 * 8, /* %ds */
+ 2 * 8, /* %es */
+ 1 * 8, /* %fs */
+ 0 * 8 /* %gs */
+};
+
+/* Offset within the thread structure where we can find the saved
+ stack pointer (%esp). */
+#define AMD64OBSD_UTHREAD_RSP_OFFSET 400
+
+static void
+amd64obsd_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 + AMD64OBSD_UTHREAD_RSP_OFFSET;
+ CORE_ADDR sp = 0;
+ gdb_byte buf[8];
+ int i;
+
+ gdb_assert (regnum >= -1);
+
+ if (regnum == -1 || regnum == AMD64_RSP_REGNUM)
+ {
+ int offset;
+
+ /* Fetch stack pointer from thread structure. */
+ sp = read_memory_unsigned_integer (sp_addr, 8, byte_order);
+
+ /* Adjust the stack pointer such that it looks as if we just
+ returned from _thread_machdep_switch. */
+ offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
+ store_unsigned_integer (buf, 8, byte_order, sp + offset);
+ regcache_raw_supply (regcache, AMD64_RSP_REGNUM, buf);
+ }
+
+ for (i = 0; i < ARRAY_SIZE (amd64obsd_uthread_reg_offset); i++)
+ {
+ if (amd64obsd_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, 8, byte_order);
+
+ /* Read the saved register from the stack frame. */
+ read_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
+ regcache_raw_supply (regcache, i, buf);
+ }
+ }
+}
+
+static void
+amd64obsd_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 + AMD64OBSD_UTHREAD_RSP_OFFSET;
+ CORE_ADDR sp = 0;
+ gdb_byte buf[8];
+ int i;
+
+ gdb_assert (regnum >= -1);
+
+ if (regnum == -1 || regnum == AMD64_RSP_REGNUM)
+ {
+ int offset;
+
+ /* Calculate the stack pointer (frame pointer) that will be
+ stored into the thread structure. */
+ offset = amd64obsd_uthread_reg_offset[AMD64_RIP_REGNUM] + 8;
+ regcache_raw_collect (regcache, AMD64_RSP_REGNUM, buf);
+ sp = extract_unsigned_integer (buf, 8, byte_order) - offset;
+
+ /* Store the stack pointer. */
+ write_memory_unsigned_integer (sp_addr, 8, 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 (amd64obsd_uthread_reg_offset); i++)
+ {
+ if (amd64obsd_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, 8, byte_order);
+
+ /* Write the register into the stack frame. */
+ regcache_raw_collect (regcache, i, buf);
+ write_memory (sp + amd64obsd_uthread_reg_offset[i], buf, 8);
+ }
+ }
+}
+/* Kernel debugging support. */
+
+/* From <machine/frame.h>. Easy since `struct trapframe' matches
+ `struct sigcontext'. */
+#define amd64obsd_tf_reg_offset amd64obsd_sc_reg_offset
+
+static struct trad_frame_cache *
+amd64obsd_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, AMD64_RSP_REGNUM);
+
+ find_pc_partial_function (func, &name, NULL, NULL);
+ if (name && startswith (name, "Xintr"))
+ addr = sp + 8; /* It's an interrupt frame. */
+ else
+ addr = sp;
+
+ for (i = 0; i < ARRAY_SIZE (amd64obsd_tf_reg_offset); i++)
+ if (amd64obsd_tf_reg_offset[i] != -1)
+ trad_frame_set_reg_addr (cache, i, addr + amd64obsd_tf_reg_offset[i]);
+
+ /* Read %cs from trap frame. */
+ addr += amd64obsd_tf_reg_offset[AMD64_CS_REGNUM];
+ cs = read_memory_unsigned_integer (addr, 8, 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 + 16, func));
+ }
+
+ return cache;
+}
+
+static void
+amd64obsd_trapframe_this_id (struct frame_info *this_frame,
+ void **this_cache, struct frame_id *this_id)
+{
+ struct trad_frame_cache *cache =
+ amd64obsd_trapframe_cache (this_frame, this_cache);
+
+ trad_frame_get_id (cache, this_id);
+}
+
+static struct value *
+amd64obsd_trapframe_prev_register (struct frame_info *this_frame,
+ void **this_cache, int regnum)
+{
+ struct trad_frame_cache *cache =
+ amd64obsd_trapframe_cache (this_frame, this_cache);
+
+ return trad_frame_get_register (cache, this_frame, regnum);
+}
+
+static int
+amd64obsd_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, AMD64_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, "osyscall1") == 0)
+ || (strcmp (name, "Xsyscall") == 0)
+ || (startswith (name, "Xintr"))));
+}
+
+static const struct frame_unwind amd64obsd_trapframe_unwind = {
+ /* FIXME: kettenis/20051219: This really is more like an interrupt
+ frame, but SIGTRAMP_FRAME would print <signal handler called>,
+ which really is not what we want here. */
+ NORMAL_FRAME,
+ default_frame_unwind_stop_reason,
+ amd64obsd_trapframe_this_id,
+ amd64obsd_trapframe_prev_register,
+ NULL,
+ amd64obsd_trapframe_sniffer
+};
+\f
+
static void
amd64obsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
amd64_init_abi (info, gdbarch);
+ obsd_init_abi (info, gdbarch);
/* Initialize general-purpose register set details. */
tdep->gregset_reg_offset = amd64obsd_r_reg_offset;
tdep->gregset_num_regs = ARRAY_SIZE (amd64obsd_r_reg_offset);
tdep->sizeof_gregset = 24 * 8;
- set_gdbarch_regset_from_core_section (gdbarch,
- amd64obsd_regset_from_core_section);
-
tdep->jb_pc_offset = 7 * 8;
- set_gdbarch_pc_in_sigtramp (gdbarch, amd64obsd_pc_in_sigtramp);
+ tdep->sigtramp_p = amd64obsd_sigtramp_p;
tdep->sigcontext_addr = amd64obsd_sigcontext_addr;
tdep->sc_reg_offset = amd64obsd_sc_reg_offset;
tdep->sc_num_regs = ARRAY_SIZE (amd64obsd_sc_reg_offset);
+ /* OpenBSD provides a user-level threads implementation. */
+ bsd_uthread_set_supply_uthread (gdbarch, amd64obsd_supply_uthread);
+ bsd_uthread_set_collect_uthread (gdbarch, amd64obsd_collect_uthread);
+
/* OpenBSD uses SVR4-style shared libraries. */
set_solib_svr4_fetch_link_map_offsets
(gdbarch, svr4_lp64_fetch_link_map_offsets);
+
+ /* Unwind kernel trap frames correctly. */
+ frame_unwind_prepend_unwinder (gdbarch, &amd64obsd_trapframe_unwind);
+}
+
+/* Traditional (a.out) NetBSD-style core dumps. */
+
+static void
+amd64obsd_core_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
+{
+ amd64obsd_init_abi (info, gdbarch);
+
+ set_gdbarch_iterate_over_regset_sections
+ (gdbarch, amd64obsd_iterate_over_regset_sections);
}
\f
/* OpenBSD uses traditional (a.out) NetBSD-style core dumps. */
gdbarch_register_osabi (bfd_arch_i386, bfd_mach_x86_64,
- GDB_OSABI_NETBSD_AOUT, amd64obsd_init_abi);
+ GDB_OSABI_NETBSD_AOUT, amd64obsd_core_init_abi);
}