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/*-
* Copyright (c) 2018 John Baldwin <jhb@FreeBSD.org>
* 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 AUTHORS ``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 AUTHORS 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.
*
*/
/* Target-dependent code for FreeBSD/arm kernels. */
#include "defs.h"
#include "arm-tdep.h"
#include "frame-unwind.h"
#include "gdbcore.h"
#include "osabi.h"
#include "regcache.h"
#include "regset.h"
#include "solib.h"
#include "target.h"
#include "trad-frame.h"
#include "kgdb.h"
static const struct regcache_map_entry arm_fbsd_pcbmap[] =
{
{ 9, 4, 4 }, /* r4 ... r12 */
{ 1, ARM_SP_REGNUM, 4 },
{ 1, ARM_LR_REGNUM, 4 },
{ 1, ARM_PC_REGNUM, 4 },
{ 0 }
};
static const struct regset arm_fbsd_pcbregset =
{
arm_fbsd_pcbmap,
regcache_supply_regset, regcache_collect_regset
};
static void
arm_fbsd_supply_pcb(struct regcache *regcache, CORE_ADDR pcb_addr)
{
gdb_byte buf[4 * 12];
if (target_read_memory (pcb_addr, buf, sizeof buf) == 0)
regcache->supply_regset (&arm_fbsd_pcbregset, -1, buf, sizeof (buf));
/*
* XXX: This is a gross hack, but the ARM frame unwinders need the value
* of xPSR to determine if Thumb mode is active. FreeBSD's kernels never
* use Thumb.
*/
regcache->raw_supply_unsigned(ARM_PS_REGNUM, 0);
}
#define PSR_MODE 0x0000001f /* mode mask */
#define PSR_USR32_MODE 0x00000010
static struct trad_frame_cache *
arm_fbsd_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;
uint32_t psr;
CORE_ADDR func, pc, sp;
const char *name;
int i;
if (*this_cache != NULL)
return ((struct trad_frame_cache *)*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, ARM_SP_REGNUM);
find_pc_partial_function (func, &name, NULL, NULL);
/* Read $PSR to determine where SP and LR are. */
psr = read_memory_unsigned_integer (sp, 4, byte_order);
for (i = 0; i <= 12; i++)
trad_frame_set_reg_addr (cache, ARM_A1_REGNUM + i, sp + 4 + i * 4);
if ((psr & PSR_MODE) == PSR_USR32_MODE)
{
trad_frame_set_reg_addr (cache, ARM_SP_REGNUM, sp + 14 * 4);
trad_frame_set_reg_addr (cache, ARM_LR_REGNUM, sp + 15 * 4);
}
else
{
trad_frame_set_reg_addr (cache, ARM_SP_REGNUM, sp + 16 * 4);
trad_frame_set_reg_addr (cache, ARM_LR_REGNUM, sp + 17 * 4);
}
trad_frame_set_reg_addr (cache, ARM_PC_REGNUM, sp + 18 * 4);
trad_frame_set_reg_addr (cache, ARM_PS_REGNUM, sp);
/* Read $PC from trap frame. */
pc = read_memory_unsigned_integer (sp + 18 * 4, 4, byte_order);
if (pc == 0 && strcmp(name, "swi_entry") == 0)
{
/* Initial frame of a kthread; 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 + 4 * 19, func));
}
return cache;
}
static void
arm_fbsd_trapframe_this_id (struct frame_info *this_frame,
void **this_cache, struct frame_id *this_id)
{
struct trad_frame_cache *cache =
arm_fbsd_trapframe_cache (this_frame, this_cache);
trad_frame_get_id (cache, this_id);
}
static struct value *
arm_fbsd_trapframe_prev_register (struct frame_info *this_frame,
void **this_cache, int regnum)
{
struct trad_frame_cache *cache =
arm_fbsd_trapframe_cache (this_frame, this_cache);
return trad_frame_get_register (cache, this_frame, regnum);
}
static int
arm_fbsd_trapframe_sniffer (const struct frame_unwind *self,
struct frame_info *this_frame,
void **this_prologue_cache)
{
const char *name;
find_pc_partial_function (get_frame_func (this_frame), &name, NULL, NULL);
return (name && ((strcmp (name, "data_abort_entry") == 0)
|| (strcmp (name, "prefetch_abort_entry") == 0)
|| (strcmp (name, "undefined_entry") == 0)
|| (strcmp (name, "exception_exit") == 0)
|| (strcmp (name, "irq_entry") == 0)
|| (strcmp (name, "swi_entry") == 0)
|| (strcmp (name, "swi_exit") == 0)));
}
static const struct frame_unwind arm_fbsd_trapframe_unwind = {
SIGTRAMP_FRAME,
default_frame_unwind_stop_reason,
arm_fbsd_trapframe_this_id,
arm_fbsd_trapframe_prev_register,
NULL,
arm_fbsd_trapframe_sniffer
};
/* Implement the 'init_osabi' method of struct gdb_osabi_handler. */
static void
arm_fbsd_kernel_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
{
struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
frame_unwind_prepend_unwinder (gdbarch, &arm_fbsd_trapframe_unwind);
set_solib_ops (gdbarch, &kld_so_ops);
tdep->jb_pc = 24;
tdep->jb_elt_size = 4;
fbsd_vmcore_set_supply_pcb (gdbarch, arm_fbsd_supply_pcb);
fbsd_vmcore_set_cpu_pcb_addr (gdbarch, kgdb_trgt_stop_pcb);
/* Single stepping. */
set_gdbarch_software_single_step (gdbarch, arm_software_single_step);
}
/* Provide a prototype to silence -Wmissing-prototypes. */
extern initialize_file_ftype _initialize_arm_kgdb_tdep;
void
_initialize_arm_kgdb_tdep (void)
{
gdbarch_register_osabi_sniffer(bfd_arch_arm,
bfd_target_elf_flavour,
fbsd_kernel_osabi_sniffer);
gdbarch_register_osabi (bfd_arch_arm, 0, GDB_OSABI_FREEBSD_KERNEL,
arm_fbsd_kernel_init_abi);
}
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