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head/devel/gdb/files/kgdb/i386fbsd-kern.c

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/*
* 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 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.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/proc.h>
#ifdef __i386__
#include <machine/pcb.h>
#include <machine/frame.h>
#include <machine/segments.h>
#include <machine/tss.h>
#endif
#include <string.h>
#include <defs.h>
#include <frame-unwind.h>
#include "gdbcore.h"
#include <inferior.h>
#include "osabi.h"
#include <regcache.h>
#include "progspace.h"
#include "solib.h"
#include "trad-frame.h"
#include <i386-tdep.h>
#include "kgdb.h"
struct i386fbsd_info {
int ofs_fix;
};
/* Per-program-space data key. */
static const struct program_space_data *i386fbsd_pspace_data;
static void
i386fbsd_pspace_data_cleanup (struct program_space *pspace, void *arg)
{
struct i386fbsd_info *info = arg;
xfree (info);
}
/* Get the current i386fbsd data. If none is found yet, add it now. This
function always returns a valid object. */
static struct i386fbsd_info *
get_i386fbsd_info (void)
{
struct i386fbsd_info *info;
info = program_space_data (current_program_space, i386fbsd_pspace_data);
if (info != NULL)
return info;
info = XCNEW (struct i386fbsd_info);
set_program_space_data (current_program_space, i386fbsd_pspace_data, info);
/*
* In revision 1.117 of i386/i386/exception.S trap handlers
* were changed to pass trapframes by reference rather than
* by value. Detect this by seeing if the first instruction
* at the 'calltrap' label is a "push %esp" which has the
* opcode 0x54.
*/
if (parse_and_eval_long("((char *)calltrap)[0]") == 0x54)
info->ofs_fix = 4;
else
info->ofs_fix = 0;
return info;
}
/*
* Even though the pcb contains fields for the segment selectors, only
* %gs is updated on each context switch. The other selectors are
* saved in stoppcbs[], but we just hardcode their known values rather
* than handling that special case.
*/
static const int i386fbsd_pcb_offset[] = {
-1, /* %eax */
-1, /* %ecx */
-1, /* %edx */
4 * 4, /* %ebx */
3 * 4, /* %esp */
2 * 4, /* %ebp */
1 * 4, /* %esi */
0 * 4, /* %edi */
5 * 4, /* %eip */
-1, /* %eflags */
-1, /* %cs */
-1, /* %ss */
-1, /* %ds */
-1, /* %es */
-1, /* %fs */
-1, /* %gs */
};
#define CODE_SEL (4 << 3)
#define DATA_SEL (5 << 3)
#define PRIV_SEL (1 << 3)
static void
i386fbsd_supply_pcb(struct regcache *regcache, CORE_ADDR pcb_addr)
{
gdb_byte buf[4];
int i;
for (i = 0; i < ARRAY_SIZE (i386fbsd_pcb_offset); i++)
if (i386fbsd_pcb_offset[i] != -1) {
if (target_read_memory(pcb_addr + i386fbsd_pcb_offset[i], buf, sizeof buf)
!= 0)
continue;
regcache_raw_supply(regcache, i, buf);
}
regcache_raw_supply_unsigned(regcache, I386_CS_REGNUM, CODE_SEL);
regcache_raw_supply_unsigned(regcache, I386_DS_REGNUM, DATA_SEL);
regcache_raw_supply_unsigned(regcache, I386_ES_REGNUM, DATA_SEL);
regcache_raw_supply_unsigned(regcache, I386_FS_REGNUM, PRIV_SEL);
regcache_raw_supply_unsigned(regcache, I386_GS_REGNUM, DATA_SEL);
regcache_raw_supply_unsigned(regcache, I386_SS_REGNUM, DATA_SEL);
}
#ifdef __i386__
/* TODO: Make this cross-debugger friendly. */
static const int i386fbsd_tss_offset[] = {
10 * 4, /* %eax */
11 * 4, /* %ecx */
12 * 4, /* %edx */
13 * 4, /* %ebx */
14 * 4, /* %esp */
15 * 4, /* %ebp */
16 * 4, /* %esi */
17 * 4, /* %edi */
8 * 4, /* %eip */
9 * 4, /* %eflags */
19 * 4, /* %cs */
20 * 4, /* %ss */
21 * 4, /* %ds */
18 * 4, /* %es */
22 * 4, /* %fs */
23 * 4, /* %gs */
};
/*
* If the current thread is executing on a CPU, fetch the common_tss
* for that CPU.
*
* This is painful because 'struct pcpu' is variant sized, so we can't
* use it. Instead, we lookup the GDT selector for this CPU and
* extract the base of the TSS from there.
*/
static CORE_ADDR
i386fbsd_fetch_tss(void)
{
struct kthr *kt;
struct segment_descriptor sd;
CORE_ADDR addr, cpu0prvpage, tss;
kt = kgdb_thr_lookup_tid(ptid_get_tid(inferior_ptid));
if (kt == NULL || kt->cpu == NOCPU || kt->cpu < 0)
return (0);
addr = kgdb_lookup("gdt");
if (addr == 0)
return (0);
addr += (kt->cpu * NGDT + GPROC0_SEL) * sizeof(sd);
if (target_read_memory(addr, (void *)&sd, sizeof(sd)) != 0)
return (0);
if (sd.sd_type != SDT_SYS386BSY) {
warning ("descriptor is not a busy TSS");
return (0);
}
tss = sd.sd_hibase << 24 | sd.sd_lobase;
/*
* In SMP kernels, the TSS is stored as part of the per-CPU
* data. On older kernels, the CPU0's private page
* is stored at an address that isn't mapped in minidumps.
* However, the data is mapped at the alternate cpu0prvpage
* address. Thus, if the TSS is at the invalid address,
* change it to be relative to cpu0prvpage instead.
*/
if (trunc_page(tss) == 0xffc00000) {
TRY {
cpu0prvpage = parse_and_eval_address("cpu0prvpage");
} CATCH(e, RETURN_MASK_ERROR) {
return (0);
} END_CATCH
tss = cpu0prvpage + (tss & PAGE_MASK);
}
return (tss);
}
static struct trad_frame_cache *
i386fbsd_dblfault_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 addr, func, tss;
int i;
if (*this_cache != NULL)
return (*this_cache);
cache = trad_frame_cache_zalloc (this_frame);
*this_cache = cache;
func = get_frame_func (this_frame);
tss = i386fbsd_fetch_tss ();
for (i = 0; i < ARRAY_SIZE (i386fbsd_tss_offset); i++)
if (i386fbsd_tss_offset[i] != -1)
trad_frame_set_reg_addr (cache, i, tss + i386fbsd_tss_offset[i]);
/* Construct the frame ID using the function start. */
/* XXX: Stack address should be dbfault_stack + PAGE_SIZE. */
trad_frame_set_id (cache, frame_id_build (tss + sizeof(struct i386tss),
func));
return cache;
}
static void
i386fbsd_dblfault_this_id (struct frame_info *this_frame,
void **this_cache, struct frame_id *this_id)
{
struct trad_frame_cache *cache =
i386fbsd_dblfault_cache (this_frame, this_cache);
trad_frame_get_id (cache, this_id);
}
static struct value *
i386fbsd_dblfault_prev_register (struct frame_info *this_frame,
void **this_cache, int regnum)
{
struct trad_frame_cache *cache =
i386fbsd_dblfault_cache (this_frame, this_cache);
return trad_frame_get_register (cache, this_frame, regnum);
}
static int
i386fbsd_dblfault_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, "dblfault_handler") == 0);
}
static const struct frame_unwind i386fbsd_dblfault_unwind = {
NORMAL_FRAME,
default_frame_unwind_stop_reason,
i386fbsd_dblfault_this_id,
i386fbsd_dblfault_prev_register,
NULL,
i386fbsd_dblfault_sniffer
};
#endif
static const int i386fbsd_trapframe_offset[] = {
10 * 4, /* %eax */
9 * 4, /* %ecx */
8 * 4, /* %edx */
7 * 4, /* %ebx */
16 * 4, /* %esp */
5 * 4, /* %ebp */
4 * 4, /* %esi */
3 * 4, /* %edi */
13 * 4, /* %eip */
15 * 4, /* %eflags */
14 * 4, /* %cs */
17 * 4, /* %ss */
2 * 4, /* %ds */
1 * 4, /* %es */
0 * 4, /* %fs */
-1 /* %gs */
};
#define TRAPFRAME_SIZE 72
static struct trad_frame_cache *
i386fbsd_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;
struct i386fbsd_info *info;
CORE_ADDR addr, cs, func, pc, sp;
const char *name;
int i;
if (*this_cache != NULL)
return (*this_cache);
info = get_i386fbsd_info();
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 (strcmp(name, "calltrap") == 0 ||
strcmp(name, "Xlcall_syscall") == 0 ||
strcmp(name, "Xint0x80_syscall") == 0)
/* Traps in later kernels pass the trap frame by reference. */
sp += info->ofs_fix;
else if (strcmp(name, "Xtimerint") == 0)
/* Timer interrupts also pass the trap frame by reference. */
sp += info->ofs_fix;
else if (strcmp(name, "Xcpustop") == 0 ||
strcmp(name, "Xrendezvous") == 0 ||
strcmp(name, "Xipi_intr_bitmap_handler") == 0 ||
strcmp(name, "Xlazypmap") == 0)
/* These handlers push a trap frame only. */
;
else if (strcmp(name, "fork_trampoline") == 0)
if (get_frame_pc (this_frame) == func)
{
/* fork_exit hasn't been called (kthread has never run), so
%esp in the pcb points to the word above the trapframe. */
sp += 4;
}
else
{
/* fork_exit has been called, so %esp in fork_exit's
frame is &tf - 12. */
sp += 12;
}
else {
/* Interrupt frames pass the IDT vector in addition to the trap frame. */
sp += info->ofs_fix + 4;
}
addr = sp + i386fbsd_trapframe_offset[I386_CS_REGNUM];
cs = read_memory_unsigned_integer (addr, 4, byte_order);
for (i = 0; i < ARRAY_SIZE (i386fbsd_trapframe_offset); i++)
{
/* %ss/%esp are only present in the trapframe for a trap from
userland. */
if ((cs & I386_SEL_RPL) == I386_SEL_KPL)
{
if (i == I386_SS_REGNUM)
continue;
if (i == I386_ESP_REGNUM)
{
trad_frame_set_reg_value (cache, i, sp + TRAPFRAME_SIZE - 8);
continue;
}
}
if (i386fbsd_trapframe_offset[i] != -1)
trad_frame_set_reg_addr (cache, i, sp + i386fbsd_trapframe_offset[i]);
}
/* Read %eip from trap frame. */
addr = sp + i386fbsd_trapframe_offset[I386_EIP_REGNUM];
pc = read_memory_unsigned_integer (addr, 4, byte_order);
if (pc == 0 && strcmp(name, "fork_trampoline") == 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. */
sp += TRAPFRAME_SIZE;
if ((cs & I386_SEL_RPL) == I386_SEL_KPL)
sp -= 8;
trad_frame_set_id (cache, frame_id_build (sp, func));
}
return cache;
}
static void
i386fbsd_trapframe_this_id (struct frame_info *this_frame,
void **this_cache, struct frame_id *this_id)
{
struct trad_frame_cache *cache =
i386fbsd_trapframe_cache (this_frame, this_cache);
trad_frame_get_id (cache, this_id);
}
static struct value *
i386fbsd_trapframe_prev_register (struct frame_info *this_frame,
void **this_cache, int regnum)
{
struct trad_frame_cache *cache =
i386fbsd_trapframe_cache (this_frame, this_cache);
return trad_frame_get_register (cache, this_frame, regnum);
}
static int
i386fbsd_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, "calltrap") == 0)
|| (strcmp (name, "fork_trampoline") == 0)
|| (name[0] == 'X' && name[1] != '_')));
}
static const struct frame_unwind i386fbsd_trapframe_unwind = {
NORMAL_FRAME,
default_frame_unwind_stop_reason,
i386fbsd_trapframe_this_id,
i386fbsd_trapframe_prev_register,
NULL,
i386fbsd_trapframe_sniffer
};
static void
i386fbsd_kernel_init_abi(struct gdbarch_info info, struct gdbarch *gdbarch)
{
i386_elf_init_abi(info, gdbarch);
#ifdef __i386__
frame_unwind_prepend_unwinder(gdbarch, &i386fbsd_dblfault_unwind);
#endif
frame_unwind_prepend_unwinder(gdbarch, &i386fbsd_trapframe_unwind);
set_solib_ops(gdbarch, &kld_so_ops);
fbsd_vmcore_set_supply_pcb(gdbarch, i386fbsd_supply_pcb);
fbsd_vmcore_set_cpu_pcb_addr(gdbarch, kgdb_trgt_stop_pcb);
}
void _initialize_i386_kgdb_tdep(void);
void
_initialize_i386_kgdb_tdep(void)
{
/* This is used for both i386 and amd64, but amd64 always
includes this target, so just include it here. */
gdbarch_register_osabi_sniffer(bfd_arch_i386,
bfd_target_elf_flavour,
fbsd_kernel_osabi_sniffer);
gdbarch_register_osabi (bfd_arch_i386, 0,
GDB_OSABI_FREEBSD_ELF_KERNEL, i386fbsd_kernel_init_abi);
i386fbsd_pspace_data = register_program_space_data_with_cleanup (NULL,
i386fbsd_pspace_data_cleanup);
#ifdef __i386__
gdb_assert(offsetof(struct pcb, pcb_ebx)
== i386fbsd_pcb_offset[I386_EBX_REGNUM]);
gdb_assert(offsetof(struct pcb, pcb_esp)
== i386fbsd_pcb_offset[I386_ESP_REGNUM]);
gdb_assert(offsetof(struct pcb, pcb_ebp)
== i386fbsd_pcb_offset[I386_EBP_REGNUM]);
gdb_assert(offsetof(struct pcb, pcb_esi)
== i386fbsd_pcb_offset[I386_ESI_REGNUM]);
gdb_assert(offsetof(struct pcb, pcb_edi)
== i386fbsd_pcb_offset[I386_EDI_REGNUM]);
gdb_assert(offsetof(struct pcb, pcb_eip)
== i386fbsd_pcb_offset[I386_EIP_REGNUM]);
gdb_assert(CODE_SEL == GSEL(GCODE_SEL, SEL_KPL));
gdb_assert(DATA_SEL == GSEL(GDATA_SEL, SEL_KPL));
gdb_assert(PRIV_SEL == GSEL(GPRIV_SEL, SEL_KPL));
gdb_assert(sizeof(struct trapframe) == TRAPFRAME_SIZE);
gdb_assert(offsetof(struct trapframe, tf_eax)
== i386fbsd_trapframe_offset[I386_EAX_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_ecx)
== i386fbsd_trapframe_offset[I386_ECX_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_edx)
== i386fbsd_trapframe_offset[I386_EDX_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_ebx)
== i386fbsd_trapframe_offset[I386_EBX_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_esp)
== i386fbsd_trapframe_offset[I386_ESP_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_ebp)
== i386fbsd_trapframe_offset[I386_EBP_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_esi)
== i386fbsd_trapframe_offset[I386_ESI_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_edi)
== i386fbsd_trapframe_offset[I386_EDI_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_eip)
== i386fbsd_trapframe_offset[I386_EIP_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_eflags)
== i386fbsd_trapframe_offset[I386_EFLAGS_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_cs)
== i386fbsd_trapframe_offset[I386_CS_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_ss)
== i386fbsd_trapframe_offset[I386_SS_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_ds)
== i386fbsd_trapframe_offset[I386_DS_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_es)
== i386fbsd_trapframe_offset[I386_ES_REGNUM]);
gdb_assert(offsetof(struct trapframe, tf_fs)
== i386fbsd_trapframe_offset[I386_FS_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_eax)
== i386fbsd_tss_offset[I386_EAX_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_ecx)
== i386fbsd_tss_offset[I386_ECX_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_edx)
== i386fbsd_tss_offset[I386_EDX_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_ebx)
== i386fbsd_tss_offset[I386_EBX_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_esp)
== i386fbsd_tss_offset[I386_ESP_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_ebp)
== i386fbsd_tss_offset[I386_EBP_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_esi)
== i386fbsd_tss_offset[I386_ESI_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_edi)
== i386fbsd_tss_offset[I386_EDI_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_eip)
== i386fbsd_tss_offset[I386_EIP_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_eflags)
== i386fbsd_tss_offset[I386_EFLAGS_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_cs)
== i386fbsd_tss_offset[I386_CS_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_ss)
== i386fbsd_tss_offset[I386_SS_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_ds)
== i386fbsd_tss_offset[I386_DS_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_es)
== i386fbsd_tss_offset[I386_ES_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_fs)
== i386fbsd_tss_offset[I386_FS_REGNUM]);
gdb_assert(offsetof(struct i386tss, tss_gs)
== i386fbsd_tss_offset[I386_GS_REGNUM]);
#endif
}