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binutils-gdb/gdb/s390-linux-nat.c
Andreas Arnez 9b44a3a57d S390: Fix erroneous offset in fill_gregset.
This fixes a bug that leads to various failures when debugging a
31-bit inferior with a 64-bit gdb on s390x.
2014-05-13 14:55:53 +02:00

701 lines
20 KiB
C

/* S390 native-dependent code for GDB, the GNU debugger.
Copyright (C) 2001-2014 Free Software Foundation, Inc.
Contributed by D.J. Barrow (djbarrow@de.ibm.com,barrow_dj@yahoo.com)
for IBM Deutschland Entwicklung GmbH, IBM Corporation.
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 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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, see <http://www.gnu.org/licenses/>. */
#include "defs.h"
#include "regcache.h"
#include "inferior.h"
#include "target.h"
#include "linux-nat.h"
#include "auxv.h"
#include "gregset.h"
#include "s390-linux-tdep.h"
#include "elf/common.h"
#include <asm/ptrace.h>
#include <sys/ptrace.h>
#include <asm/types.h>
#include <sys/procfs.h>
#include <sys/ucontext.h>
#include <elf.h>
#ifndef PTRACE_GETREGSET
#define PTRACE_GETREGSET 0x4204
#endif
#ifndef PTRACE_SETREGSET
#define PTRACE_SETREGSET 0x4205
#endif
static int have_regset_last_break = 0;
static int have_regset_system_call = 0;
static int have_regset_tdb = 0;
/* Map registers to gregset/ptrace offsets.
These arrays are defined in s390-tdep.c. */
#ifdef __s390x__
#define regmap_gregset s390x_regmap_gregset
#else
#define regmap_gregset s390_regmap_gregset
#endif
#define regmap_fpregset s390_regmap_fpregset
/* Fill the regset described by MAP into REGCACHE, using the values
from REGP. The MAP array represents each register as a pair
(offset, regno) of short integers and is terminated with -1. */
static void
s390_native_supply (struct regcache *regcache, const short *map,
const gdb_byte *regp)
{
for (; map[0] >= 0; map += 2)
regcache_raw_supply (regcache, map[1], regp ? regp + map[0] : NULL);
}
/* Collect the register REGNO out of the regset described by MAP from
REGCACHE into REGP. If REGNO == -1, do this for all registers in
this regset. */
static void
s390_native_collect (const struct regcache *regcache, const short *map,
int regno, gdb_byte *regp)
{
for (; map[0] >= 0; map += 2)
if (regno == -1 || regno == map[1])
regcache_raw_collect (regcache, map[1], regp + map[0]);
}
/* Fill GDB's register array with the general-purpose register values
in *REGP.
When debugging a 32-bit executable running under a 64-bit kernel,
we have to fix up the 64-bit registers we get from the kernel to
make them look like 32-bit registers. */
void
supply_gregset (struct regcache *regcache, const gregset_t *regp)
{
#ifdef __s390x__
struct gdbarch *gdbarch = get_regcache_arch (regcache);
if (gdbarch_ptr_bit (gdbarch) == 32)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
ULONGEST pswm = 0, pswa = 0;
gdb_byte buf[4];
const short *map;
for (map = regmap_gregset; map[0] >= 0; map += 2)
{
const gdb_byte *p = (const gdb_byte *) regp + map[0];
int regno = map[1];
if (regno == S390_PSWM_REGNUM)
pswm = extract_unsigned_integer (p, 8, byte_order);
else if (regno == S390_PSWA_REGNUM)
pswa = extract_unsigned_integer (p, 8, byte_order);
else
{
if ((regno >= S390_R0_REGNUM && regno <= S390_R15_REGNUM)
|| regno == S390_ORIG_R2_REGNUM)
p += 4;
regcache_raw_supply (regcache, regno, p);
}
}
store_unsigned_integer (buf, 4, byte_order, (pswm >> 32) | 0x80000);
regcache_raw_supply (regcache, S390_PSWM_REGNUM, buf);
store_unsigned_integer (buf, 4, byte_order,
(pswa & 0x7fffffff) | (pswm & 0x80000000));
regcache_raw_supply (regcache, S390_PSWA_REGNUM, buf);
return;
}
#endif
s390_native_supply (regcache, regmap_gregset, (const gdb_byte *) regp);
}
/* Fill register REGNO (if it is a general-purpose register) in
*REGP with the value in GDB's register array. If REGNO is -1,
do this for all registers. */
void
fill_gregset (const struct regcache *regcache, gregset_t *regp, int regno)
{
#ifdef __s390x__
struct gdbarch *gdbarch = get_regcache_arch (regcache);
if (gdbarch_ptr_bit (gdbarch) == 32)
{
gdb_byte *psw_p[2];
const short *map;
for (map = regmap_gregset; map[0] >= 0; map += 2)
{
gdb_byte *p = (gdb_byte *) regp + map[0];
int reg = map[1];
if (reg >= S390_PSWM_REGNUM && reg <= S390_PSWA_REGNUM)
psw_p[reg - S390_PSWM_REGNUM] = p;
else if (regno == -1 || regno == reg)
{
if ((reg >= S390_R0_REGNUM && reg <= S390_R15_REGNUM)
|| reg == S390_ORIG_R2_REGNUM)
{
memset (p, 0, 4);
p += 4;
}
regcache_raw_collect (regcache, reg, p);
}
}
if (regno == -1
|| regno == S390_PSWM_REGNUM || regno == S390_PSWA_REGNUM)
{
enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
ULONGEST pswa, pswm;
gdb_byte buf[4];
regcache_raw_collect (regcache, S390_PSWM_REGNUM, buf);
pswm = extract_unsigned_integer (buf, 4, byte_order);
regcache_raw_collect (regcache, S390_PSWA_REGNUM, buf);
pswa = extract_unsigned_integer (buf, 4, byte_order);
if (regno == -1 || regno == S390_PSWM_REGNUM)
store_unsigned_integer (psw_p[0], 8, byte_order,
((pswm & 0xfff7ffff) << 32) |
(pswa & 0x80000000));
if (regno == -1 || regno == S390_PSWA_REGNUM)
store_unsigned_integer (psw_p[1], 8, byte_order,
pswa & 0x7fffffff);
}
return;
}
#endif
s390_native_collect (regcache, regmap_gregset, regno, (gdb_byte *) regp);
}
/* Fill GDB's register array with the floating-point register values
in *REGP. */
void
supply_fpregset (struct regcache *regcache, const fpregset_t *regp)
{
s390_native_supply (regcache, regmap_fpregset, (const gdb_byte *) regp);
}
/* Fill register REGNO (if it is a general-purpose register) in
*REGP with the value in GDB's register array. If REGNO is -1,
do this for all registers. */
void
fill_fpregset (const struct regcache *regcache, fpregset_t *regp, int regno)
{
s390_native_collect (regcache, regmap_fpregset, regno, (gdb_byte *) regp);
}
/* Find the TID for the current inferior thread to use with ptrace. */
static int
s390_inferior_tid (void)
{
/* GNU/Linux LWP ID's are process ID's. */
int tid = ptid_get_lwp (inferior_ptid);
if (tid == 0)
tid = ptid_get_pid (inferior_ptid); /* Not a threaded program. */
return tid;
}
/* Fetch all general-purpose registers from process/thread TID and
store their values in GDB's register cache. */
static void
fetch_regs (struct regcache *regcache, int tid)
{
gregset_t regs;
ptrace_area parea;
parea.len = sizeof (regs);
parea.process_addr = (addr_t) &regs;
parea.kernel_addr = offsetof (struct user_regs_struct, psw);
if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
perror_with_name (_("Couldn't get registers"));
supply_gregset (regcache, (const gregset_t *) &regs);
}
/* Store all valid general-purpose registers in GDB's register cache
into the process/thread specified by TID. */
static void
store_regs (const struct regcache *regcache, int tid, int regnum)
{
gregset_t regs;
ptrace_area parea;
parea.len = sizeof (regs);
parea.process_addr = (addr_t) &regs;
parea.kernel_addr = offsetof (struct user_regs_struct, psw);
if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
perror_with_name (_("Couldn't get registers"));
fill_gregset (regcache, &regs, regnum);
if (ptrace (PTRACE_POKEUSR_AREA, tid, (long) &parea) < 0)
perror_with_name (_("Couldn't write registers"));
}
/* Fetch all floating-point registers from process/thread TID and store
their values in GDB's register cache. */
static void
fetch_fpregs (struct regcache *regcache, int tid)
{
fpregset_t fpregs;
ptrace_area parea;
parea.len = sizeof (fpregs);
parea.process_addr = (addr_t) &fpregs;
parea.kernel_addr = offsetof (struct user_regs_struct, fp_regs);
if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
perror_with_name (_("Couldn't get floating point status"));
supply_fpregset (regcache, (const fpregset_t *) &fpregs);
}
/* Store all valid floating-point registers in GDB's register cache
into the process/thread specified by TID. */
static void
store_fpregs (const struct regcache *regcache, int tid, int regnum)
{
fpregset_t fpregs;
ptrace_area parea;
parea.len = sizeof (fpregs);
parea.process_addr = (addr_t) &fpregs;
parea.kernel_addr = offsetof (struct user_regs_struct, fp_regs);
if (ptrace (PTRACE_PEEKUSR_AREA, tid, (long) &parea) < 0)
perror_with_name (_("Couldn't get floating point status"));
fill_fpregset (regcache, &fpregs, regnum);
if (ptrace (PTRACE_POKEUSR_AREA, tid, (long) &parea) < 0)
perror_with_name (_("Couldn't write floating point status"));
}
/* Fetch all registers in the kernel's register set whose number is REGSET,
whose size is REGSIZE, and whose layout is described by REGMAP, from
process/thread TID and store their values in GDB's register cache. */
static void
fetch_regset (struct regcache *regcache, int tid,
int regset, int regsize, const short *regmap)
{
gdb_byte *buf = alloca (regsize);
struct iovec iov;
iov.iov_base = buf;
iov.iov_len = regsize;
if (ptrace (PTRACE_GETREGSET, tid, (long) regset, (long) &iov) < 0)
{
if (errno == ENODATA)
s390_native_supply (regcache, regmap, NULL);
else
perror_with_name (_("Couldn't get register set"));
}
else
s390_native_supply (regcache, regmap, buf);
}
/* Store all registers in the kernel's register set whose number is REGSET,
whose size is REGSIZE, and whose layout is described by REGMAP, from
GDB's register cache back to process/thread TID. */
static void
store_regset (struct regcache *regcache, int tid,
int regset, int regsize, const short *regmap)
{
gdb_byte *buf = alloca (regsize);
struct iovec iov;
iov.iov_base = buf;
iov.iov_len = regsize;
if (ptrace (PTRACE_GETREGSET, tid, (long) regset, (long) &iov) < 0)
perror_with_name (_("Couldn't get register set"));
s390_native_collect (regcache, regmap, -1, buf);
if (ptrace (PTRACE_SETREGSET, tid, (long) regset, (long) &iov) < 0)
perror_with_name (_("Couldn't set register set"));
}
/* Check whether the kernel provides a register set with number REGSET
of size REGSIZE for process/thread TID. */
static int
check_regset (int tid, int regset, int regsize)
{
gdb_byte *buf = alloca (regsize);
struct iovec iov;
iov.iov_base = buf;
iov.iov_len = regsize;
if (ptrace (PTRACE_GETREGSET, tid, (long) regset, (long) &iov) >= 0
|| errno == ENODATA)
return 1;
return 0;
}
/* Fetch register REGNUM from the child process. If REGNUM is -1, do
this for all registers. */
static void
s390_linux_fetch_inferior_registers (struct target_ops *ops,
struct regcache *regcache, int regnum)
{
int tid = s390_inferior_tid ();
if (regnum == -1 || S390_IS_GREGSET_REGNUM (regnum))
fetch_regs (regcache, tid);
if (regnum == -1 || S390_IS_FPREGSET_REGNUM (regnum))
fetch_fpregs (regcache, tid);
if (have_regset_last_break)
if (regnum == -1 || regnum == S390_LAST_BREAK_REGNUM)
fetch_regset (regcache, tid, NT_S390_LAST_BREAK, 8,
(gdbarch_ptr_bit (get_regcache_arch (regcache)) == 32
? s390_regmap_last_break : s390x_regmap_last_break));
if (have_regset_system_call)
if (regnum == -1 || regnum == S390_SYSTEM_CALL_REGNUM)
fetch_regset (regcache, tid, NT_S390_SYSTEM_CALL, 4,
s390_regmap_system_call);
if (have_regset_tdb)
if (regnum == -1 || S390_IS_TDBREGSET_REGNUM (regnum))
fetch_regset (regcache, tid, NT_S390_TDB, s390_sizeof_tdbregset,
s390_regmap_tdb);
}
/* Store register REGNUM back into the child process. If REGNUM is
-1, do this for all registers. */
static void
s390_linux_store_inferior_registers (struct target_ops *ops,
struct regcache *regcache, int regnum)
{
int tid = s390_inferior_tid ();
if (regnum == -1 || S390_IS_GREGSET_REGNUM (regnum))
store_regs (regcache, tid, regnum);
if (regnum == -1 || S390_IS_FPREGSET_REGNUM (regnum))
store_fpregs (regcache, tid, regnum);
/* S390_LAST_BREAK_REGNUM is read-only. */
if (have_regset_system_call)
if (regnum == -1 || regnum == S390_SYSTEM_CALL_REGNUM)
store_regset (regcache, tid, NT_S390_SYSTEM_CALL, 4,
s390_regmap_system_call);
}
/* Hardware-assisted watchpoint handling. */
/* We maintain a list of all currently active watchpoints in order
to properly handle watchpoint removal.
The only thing we actually need is the total address space area
spanned by the watchpoints. */
struct watch_area
{
struct watch_area *next;
CORE_ADDR lo_addr;
CORE_ADDR hi_addr;
};
static struct watch_area *watch_base = NULL;
static int
s390_stopped_by_watchpoint (struct target_ops *ops)
{
per_lowcore_bits per_lowcore;
ptrace_area parea;
int result;
/* Speed up common case. */
if (!watch_base)
return 0;
parea.len = sizeof (per_lowcore);
parea.process_addr = (addr_t) & per_lowcore;
parea.kernel_addr = offsetof (struct user_regs_struct, per_info.lowcore);
if (ptrace (PTRACE_PEEKUSR_AREA, s390_inferior_tid (), &parea) < 0)
perror_with_name (_("Couldn't retrieve watchpoint status"));
result = (per_lowcore.perc_storage_alteration == 1
&& per_lowcore.perc_store_real_address == 0);
if (result)
{
/* Do not report this watchpoint again. */
memset (&per_lowcore, 0, sizeof (per_lowcore));
if (ptrace (PTRACE_POKEUSR_AREA, s390_inferior_tid (), &parea) < 0)
perror_with_name (_("Couldn't clear watchpoint status"));
}
return result;
}
static void
s390_fix_watch_points (struct lwp_info *lp)
{
int tid;
per_struct per_info;
ptrace_area parea;
CORE_ADDR watch_lo_addr = (CORE_ADDR)-1, watch_hi_addr = 0;
struct watch_area *area;
tid = ptid_get_lwp (lp->ptid);
if (tid == 0)
tid = ptid_get_pid (lp->ptid);
for (area = watch_base; area; area = area->next)
{
watch_lo_addr = min (watch_lo_addr, area->lo_addr);
watch_hi_addr = max (watch_hi_addr, area->hi_addr);
}
parea.len = sizeof (per_info);
parea.process_addr = (addr_t) & per_info;
parea.kernel_addr = offsetof (struct user_regs_struct, per_info);
if (ptrace (PTRACE_PEEKUSR_AREA, tid, &parea) < 0)
perror_with_name (_("Couldn't retrieve watchpoint status"));
if (watch_base)
{
per_info.control_regs.bits.em_storage_alteration = 1;
per_info.control_regs.bits.storage_alt_space_ctl = 1;
}
else
{
per_info.control_regs.bits.em_storage_alteration = 0;
per_info.control_regs.bits.storage_alt_space_ctl = 0;
}
per_info.starting_addr = watch_lo_addr;
per_info.ending_addr = watch_hi_addr;
if (ptrace (PTRACE_POKEUSR_AREA, tid, &parea) < 0)
perror_with_name (_("Couldn't modify watchpoint status"));
}
static int
s390_insert_watchpoint (struct target_ops *self,
CORE_ADDR addr, int len, int type,
struct expression *cond)
{
struct lwp_info *lp;
struct watch_area *area = xmalloc (sizeof (struct watch_area));
if (!area)
return -1;
area->lo_addr = addr;
area->hi_addr = addr + len - 1;
area->next = watch_base;
watch_base = area;
ALL_LWPS (lp)
s390_fix_watch_points (lp);
return 0;
}
static int
s390_remove_watchpoint (struct target_ops *self,
CORE_ADDR addr, int len, int type,
struct expression *cond)
{
struct lwp_info *lp;
struct watch_area *area, **parea;
for (parea = &watch_base; *parea; parea = &(*parea)->next)
if ((*parea)->lo_addr == addr
&& (*parea)->hi_addr == addr + len - 1)
break;
if (!*parea)
{
fprintf_unfiltered (gdb_stderr,
"Attempt to remove nonexistent watchpoint.\n");
return -1;
}
area = *parea;
*parea = area->next;
xfree (area);
ALL_LWPS (lp)
s390_fix_watch_points (lp);
return 0;
}
static int
s390_can_use_hw_breakpoint (struct target_ops *self,
int type, int cnt, int othertype)
{
return type == bp_hardware_watchpoint;
}
static int
s390_region_ok_for_hw_watchpoint (struct target_ops *self,
CORE_ADDR addr, int cnt)
{
return 1;
}
static int
s390_target_wordsize (void)
{
int wordsize = 4;
/* Check for 64-bit inferior process. This is the case when the host is
64-bit, and in addition bit 32 of the PSW mask is set. */
#ifdef __s390x__
long pswm;
errno = 0;
pswm = (long) ptrace (PTRACE_PEEKUSER, s390_inferior_tid (), PT_PSWMASK, 0);
if (errno == 0 && (pswm & 0x100000000ul) != 0)
wordsize = 8;
#endif
return wordsize;
}
static int
s390_auxv_parse (struct target_ops *ops, gdb_byte **readptr,
gdb_byte *endptr, CORE_ADDR *typep, CORE_ADDR *valp)
{
int sizeof_auxv_field = s390_target_wordsize ();
enum bfd_endian byte_order = gdbarch_byte_order (target_gdbarch ());
gdb_byte *ptr = *readptr;
if (endptr == ptr)
return 0;
if (endptr - ptr < sizeof_auxv_field * 2)
return -1;
*typep = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order);
ptr += sizeof_auxv_field;
*valp = extract_unsigned_integer (ptr, sizeof_auxv_field, byte_order);
ptr += sizeof_auxv_field;
*readptr = ptr;
return 1;
}
#ifdef __s390x__
static unsigned long
s390_get_hwcap (void)
{
CORE_ADDR field;
if (target_auxv_search (&current_target, AT_HWCAP, &field))
return (unsigned long) field;
return 0;
}
#endif
static const struct target_desc *
s390_read_description (struct target_ops *ops)
{
int tid = s390_inferior_tid ();
have_regset_last_break
= check_regset (tid, NT_S390_LAST_BREAK, 8);
have_regset_system_call
= check_regset (tid, NT_S390_SYSTEM_CALL, 4);
#ifdef __s390x__
/* If GDB itself is compiled as 64-bit, we are running on a machine in
z/Architecture mode. If the target is running in 64-bit addressing
mode, report s390x architecture. If the target is running in 31-bit
addressing mode, but the kernel supports using 64-bit registers in
that mode, report s390 architecture with 64-bit GPRs. */
have_regset_tdb = (s390_get_hwcap () & HWCAP_S390_TE) ?
check_regset (tid, NT_S390_TDB, s390_sizeof_tdbregset) : 0;
if (s390_target_wordsize () == 8)
return (have_regset_tdb ? tdesc_s390x_te_linux64 :
have_regset_system_call? tdesc_s390x_linux64v2 :
have_regset_last_break? tdesc_s390x_linux64v1 :
tdesc_s390x_linux64);
if (s390_get_hwcap () & HWCAP_S390_HIGH_GPRS)
return (have_regset_tdb ? tdesc_s390_te_linux64 :
have_regset_system_call? tdesc_s390_linux64v2 :
have_regset_last_break? tdesc_s390_linux64v1 :
tdesc_s390_linux64);
#endif
/* If GDB itself is compiled as 31-bit, or if we're running a 31-bit inferior
on a 64-bit kernel that does not support using 64-bit registers in 31-bit
mode, report s390 architecture with 32-bit GPRs. */
return (have_regset_system_call? tdesc_s390_linux32v2 :
have_regset_last_break? tdesc_s390_linux32v1 :
tdesc_s390_linux32);
}
void _initialize_s390_nat (void);
void
_initialize_s390_nat (void)
{
struct target_ops *t;
/* Fill in the generic GNU/Linux methods. */
t = linux_target ();
/* Add our register access methods. */
t->to_fetch_registers = s390_linux_fetch_inferior_registers;
t->to_store_registers = s390_linux_store_inferior_registers;
/* Add our watchpoint methods. */
t->to_can_use_hw_breakpoint = s390_can_use_hw_breakpoint;
t->to_region_ok_for_hw_watchpoint = s390_region_ok_for_hw_watchpoint;
t->to_have_continuable_watchpoint = 1;
t->to_stopped_by_watchpoint = s390_stopped_by_watchpoint;
t->to_insert_watchpoint = s390_insert_watchpoint;
t->to_remove_watchpoint = s390_remove_watchpoint;
/* Detect target architecture. */
t->to_read_description = s390_read_description;
t->to_auxv_parse = s390_auxv_parse;
/* Register the target. */
linux_nat_add_target (t);
linux_nat_set_new_thread (t, s390_fix_watch_points);
}