binutils-gdb/gdb/arm-fbsd-nat.c
John Baldwin 97b6e0f6c8 *-fbsd-nat: Handle null inferior in read_description.
Don't invoke ptrace in the target read_description method if there is
not an active inferior to query via ptrace.  Instead, use the default
register set for the architecture.

Previously the native target could report an error from a failed
ptrace operation when fetching a tdesc without an attached process.
For example on FreeBSD/amd64:

(gdb) target native
Done.  Use the "run" command to start a process.
(gdb) unset tdesc filename
Couldn't get registers: Operation not permitted.
2023-07-14 08:39:24 -07:00

114 lines
3.2 KiB
C

/* Native-dependent code for FreeBSD/arm.
Copyright (C) 2017-2023 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 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 "inferior.h"
#include "target.h"
#include "elf/common.h"
#include <sys/types.h>
#include <sys/ptrace.h>
#include <machine/reg.h>
#include "fbsd-nat.h"
#include "arm-tdep.h"
#include "arm-fbsd-tdep.h"
#include "inf-ptrace.h"
struct arm_fbsd_nat_target : public fbsd_nat_target
{
void fetch_registers (struct regcache *, int) override;
void store_registers (struct regcache *, int) override;
const struct target_desc *read_description () override;
};
static arm_fbsd_nat_target the_arm_fbsd_nat_target;
/* Fetch register REGNUM from the inferior. If REGNUM is -1, do this
for all registers. */
void
arm_fbsd_nat_target::fetch_registers (struct regcache *regcache, int regnum)
{
fetch_register_set<struct reg> (regcache, regnum, PT_GETREGS,
&arm_fbsd_gregset);
#ifdef PT_GETVFPREGS
fetch_register_set<struct vfpreg> (regcache, regnum, PT_GETVFPREGS,
&arm_fbsd_vfpregset);
#endif
#ifdef PT_GETREGSET
gdbarch *gdbarch = regcache->arch ();
arm_gdbarch_tdep *tdep = gdbarch_tdep<arm_gdbarch_tdep> (gdbarch);
if (tdep->tls_regnum > 0)
fetch_regset<uint32_t> (regcache, regnum, NT_ARM_TLS, &arm_fbsd_tls_regset,
tdep->tls_regnum);
#endif
}
/* Store register REGNUM back into the inferior. If REGNUM is -1, do
this for all registers. */
void
arm_fbsd_nat_target::store_registers (struct regcache *regcache, int regnum)
{
store_register_set<struct reg> (regcache, regnum, PT_GETREGS, PT_SETREGS,
&arm_fbsd_gregset);
#ifdef PT_GETVFPREGS
store_register_set<struct vfpreg> (regcache, regnum, PT_GETVFPREGS,
PT_SETVFPREGS, &arm_fbsd_vfpregset);
#endif
#ifdef PT_GETREGSET
gdbarch *gdbarch = regcache->arch ();
arm_gdbarch_tdep *tdep = gdbarch_tdep<arm_gdbarch_tdep> (gdbarch);
if (tdep->tls_regnum > 0)
store_regset<uint32_t> (regcache, regnum, NT_ARM_TLS, &arm_fbsd_tls_regset,
tdep->tls_regnum);
#endif
}
/* Implement the to_read_description method. */
const struct target_desc *
arm_fbsd_nat_target::read_description ()
{
const struct target_desc *desc;
bool tls = false;
if (inferior_ptid == null_ptid)
return this->beneath ()->read_description ();
#ifdef PT_GETREGSET
tls = have_regset (inferior_ptid, NT_ARM_TLS) != 0;
#endif
desc = arm_fbsd_read_description_auxv (tls);
if (desc == NULL)
desc = this->beneath ()->read_description ();
return desc;
}
void _initialize_arm_fbsd_nat ();
void
_initialize_arm_fbsd_nat ()
{
add_inf_child_target (&the_arm_fbsd_nat_target);
}