freebsd-dev/sys/ia64/include/db_machdep.h
Marcel Moolenaar a2aeb24eff Implement functions calls from within DDB on ia64. On ia64 a function
pointer doesn't point to the first instruction of that function, but
rather to a descriptor. The descriptor has the address of the first
instruction, as well as the value of the global pointer. The symbol
table doesn't know anything about descriptors, so if you lookup the
name of a function you get the address of the first instruction. The
cast from the address, which is the result of the symbol lookup, to a
function pointer as is done in db_fncall is therefore invalid.
Abstract this detail behind the DB_CALL macro. By default DB_CALL is
defined as db_fncall_generic, which yields the old behaviour. On ia64
the macro is defined as db_fncall_ia64, in which a descriptor is
constructed to yield a valid function pointer.

While here, introduce DB_MAXARGS. DB_MAXARGS replaces the existing
(local) MAXARGS. The DB_MAXARGS macro can be defined by platforms to
create a convenient maximum. By default this will be the legacy 10.
On ia64 we define this macro to be 8, for 8 is the maximum number of
arguments that can be passed in registers. This avoids having to
implement spilling of arguments on the memory stack.

Approved by: re (dwhite)
2005-07-02 23:52:37 +00:00

81 lines
2.9 KiB
C

/*-
* Copyright (c) 2004 Marcel Moolenaar
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* $FreeBSD$
*/
#ifndef _MACHINE_DB_MACHDEP_H_
#define _MACHINE_DB_MACHDEP_H_
#include <machine/ia64_cpu.h>
/* We define some of our own commands. */
#define DB_MACHINE_COMMANDS
/* We use Elf64 symbols in DDB. */
#define DB_ELFSIZE 64
/* Pretty arbitrary. */
#define DB_SMALL_VALUE_MAX 0x7fffffff
#define DB_SMALL_VALUE_MIN (-0x400001)
typedef vm_offset_t db_addr_t; /* address - unsigned */
typedef long db_expr_t; /* expression - signed */
#define PC_REGS() ((kdb_thrctx->pcb_special.__spare == 0) ? \
kdb_thrctx->pcb_special.rp : \
kdb_thrctx->pcb_special.iip + ((kdb_thrctx->pcb_special.psr>>41) & 3))
#define BKPT_WRITE(addr, storage) db_bkpt_write(addr, storage)
#define BKPT_CLEAR(addr, storage) db_bkpt_clear(addr, storage)
#define BKPT_SKIP db_bkpt_skip()
#define BKPT_INST_TYPE uint64_t
void db_bkpt_write(db_addr_t, BKPT_INST_TYPE *storage);
void db_bkpt_clear(db_addr_t, uint64_t *storage);
void db_bkpt_skip(void);
#define db_clear_single_step kdb_cpu_clear_singlestep
#define db_set_single_step kdb_cpu_set_singlestep
#define IS_BREAKPOINT_TRAP(type, code) (type == IA64_VEC_BREAK)
#define IS_WATCHPOINT_TRAP(type, code) 0
#define inst_trap_return(ins) (ins & 0)
#define inst_return(ins) (ins & 0)
#define inst_call(ins) (ins & 0)
#define inst_branch(ins) (ins & 0)
#define inst_load(ins) (ins & 0)
#define inst_store(ins) (ins & 0)
#define inst_unconditional_flow_transfer(ins) (ins & 0)
#define branch_taken(ins, pc, regs) pc
/* Function call support. */
#define DB_MAXARGS 8 /* Only support arguments in registers. */
#define DB_CALL db_fncall_ia64
#endif /* _MACHINE_DB_MACHDEP_H_ */