binutils-gdb/gdb/gdbserver/tdesc.c
Joel Brobecker 190852c8ac gdbserver/Windows: crash during connection establishment phase
On Windows, starting a new process with GDBserver seems to work,
in the sense that the program does get started, and GDBserver
confirms that it is listening for GDB to connect. However, as soon as
GDB establishes the connection with GDBserver, and starts discussing
with it, GDBserver crashes, with a SEGV.

This SEGV occurs in remote-utils.c::prepare_resume_reply...

  | regp = current_target_desc ()->expedite_regs;
  | [...]
  | while (*regp)

... because, in our case, REGP is NULL.

This patches fixes the issues by adding a parameter to init_target_desc,
in order to make sure that we always provide the list of registers when
we initialize a target description.

gdb/ChangeLog:

        PR server/23158:
        * regformats/regdat.sh: Adjust script, following the addition
        of the new expedite_regs parameter to init_target_desc.

gdb/gdbserver/ChangeLog:

        PR server/23158:
        * tdesc.h (init_target_desc) <expedite_regs>: New parameter.
        * tdesc.c (init_target_desc) <expedite_regs>: New parameter.
        Use it to set the expedite_regs field in the given tdesc.
        * x86-tdesc.h: New file.
        * linux-aarch64-tdesc.c (aarch64_linux_read_description):
        Adjust following the addition of the new expedite_regs parameter
        to init_target_desc.
        * linux-tic6x-low.c (tic6x_read_description): Likewise.
        * linux-x86-tdesc.c: #include "x86-tdesc.h".
        (i386_linux_read_description, amd64_linux_read_description):
        Adjust following the addition of the new expedite_regs parameter
        to init_target_desc.
        * lynx-i386-low.c: #include "x86-tdesc.h".
        (lynx_i386_arch_setup): Adjust following the addition of the new
        expedite_regs parameter to init_target_desc.
        * nto-x86-low.c: #include "x86-tdesc.h".
        (nto_x86_arch_setup): Adjust following the addition of the new
        expedite_regs parameter to init_target_desc.
        * win32-i386-low.c: #include "x86-tdesc.h".
        (i386_arch_setup): Adjust following the addition of the new
        expedite_regs parameter to init_target_desc.
2018-05-10 11:27:13 -04:00

189 lines
4.2 KiB
C

/* Copyright (C) 2012-2018 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 "server.h"
#include "tdesc.h"
#include "regdef.h"
#ifndef IN_PROCESS_AGENT
target_desc::~target_desc ()
{
xfree ((char *) arch);
xfree ((char *) osabi);
}
bool target_desc::operator== (const target_desc &other) const
{
if (reg_defs != other.reg_defs)
return false;
/* Compare expedite_regs. */
int i = 0;
for (; expedite_regs[i] != NULL; i++)
{
if (strcmp (expedite_regs[i], other.expedite_regs[i]) != 0)
return false;
}
if (other.expedite_regs[i] != NULL)
return false;
return true;
}
#endif
void target_desc::accept (tdesc_element_visitor &v) const
{
#ifndef IN_PROCESS_AGENT
v.visit_pre (this);
for (const tdesc_feature_up &feature : features)
feature->accept (v);
v.visit_post (this);
#endif
}
void
init_target_desc (struct target_desc *tdesc,
const char **expedite_regs)
{
int offset = 0;
/* Go through all the features and populate reg_defs. */
for (const tdesc_feature_up &feature : tdesc->features)
for (const tdesc_reg_up &treg : feature->registers)
{
int regnum = treg->target_regnum;
/* Register number will increase (possibly with gaps) or be zero. */
gdb_assert (regnum == 0 || regnum >= tdesc->reg_defs.size ());
if (regnum != 0)
tdesc->reg_defs.resize (regnum, reg (offset));
tdesc->reg_defs.emplace_back (treg->name.c_str (), offset,
treg->bitsize);
offset += treg->bitsize;
}
tdesc->registers_size = offset / 8;
/* Make sure PBUFSIZ is large enough to hold a full register
packet. */
gdb_assert (2 * tdesc->registers_size + 32 <= PBUFSIZ);
#ifndef IN_PROCESS_AGENT
tdesc->expedite_regs = expedite_regs;
#endif
}
struct target_desc *
allocate_target_description (void)
{
return new target_desc ();
}
#ifndef IN_PROCESS_AGENT
static const struct target_desc default_description {};
void
copy_target_description (struct target_desc *dest,
const struct target_desc *src)
{
dest->reg_defs = src->reg_defs;
dest->expedite_regs = src->expedite_regs;
dest->registers_size = src->registers_size;
dest->xmltarget = src->xmltarget;
}
const struct target_desc *
current_target_desc (void)
{
if (current_thread == NULL)
return &default_description;
return current_process ()->tdesc;
}
/* See common/tdesc.h. */
const char *
tdesc_architecture_name (const struct target_desc *target_desc)
{
return target_desc->arch;
}
/* See common/tdesc.h. */
void
set_tdesc_architecture (struct target_desc *target_desc,
const char *name)
{
target_desc->arch = xstrdup (name);
}
/* See common/tdesc.h. */
const char *
tdesc_osabi_name (const struct target_desc *target_desc)
{
return target_desc->osabi;
}
/* See common/tdesc.h. */
void
set_tdesc_osabi (struct target_desc *target_desc, const char *name)
{
target_desc->osabi = xstrdup (name);
}
/* See common/tdesc.h. */
const char *
tdesc_get_features_xml (const target_desc *tdesc)
{
/* Either .xmltarget or .features is not NULL. */
gdb_assert (tdesc->xmltarget != NULL
|| (!tdesc->features.empty ()
&& tdesc->arch != NULL));
if (tdesc->xmltarget == NULL)
{
std::string buffer ("@");
print_xml_feature v (&buffer);
tdesc->accept (v);
tdesc->xmltarget = xstrdup (buffer.c_str ());
}
return tdesc->xmltarget;
}
#endif
/* See common/tdesc.h. */
struct tdesc_feature *
tdesc_create_feature (struct target_desc *tdesc, const char *name)
{
struct tdesc_feature *new_feature = new tdesc_feature (name);
tdesc->features.emplace_back (new_feature);
return new_feature;
}