[PR symtab/21126] Fix handling of fully zeroed PT_GNU_RELRO

[Luis Machado]

On 02/09/2017 06:01 PM, Doug Evans via gdb-patches wrote:
> diff --git a/gdb/solib-svr4.c b/gdb/solib-svr4.c
> index 4f52251a62..82904fe588 100644
> --- a/gdb/solib-svr4.c
> +++ b/gdb/solib-svr4.c
> @@ -2777,25 +2777,10 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
>
>            /* Strip modifies the flags and alignment of PT_GNU_RELRO.
>               CentOS-5 has problems with filesz, memsz as well.
> -             See PR 11786.  */
> +             And strip may now fully zero out the section, so just
> +             ignore it. See PR 11786, 21126.  */

Two spaces after period.

> @@ -2908,25 +2893,10 @@ svr4_exec_displacement (CORE_ADDR *displacementp)
>
>            /* Strip modifies the flags and alignment of PT_GNU_RELRO.
>               CentOS-5 has problems with filesz, memsz as well.
> -             See PR 11786.  */
> +             And strip may now fully zero out the section, so just
> +             ignore it. See PR 11786, 21126.  */

Two spaces after period.

> diff --git a/gdb/testsuite/gdb.server/stripped-pie.exp
> b/gdb/testsuite/gdb.server/stripped-pie.exp
> new file mode 100644
> index 0000000000..330b0597b8
> --- /dev/null
> +++ b/gdb/testsuite/gdb.server/stripped-pie.exp
> @@ -0,0 +1,55 @@
> +# Copyright 2017 Free Software Foundation, Inc.
> +
> +# 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/>.
> +
> +# PR 21126
> +# strip may completely nullify the PT_GNU_RELRO segment header.
> +# Seeing this bug requires exec_bfd to be from the non-stripped binary,
> +# with the in-memory image being from the stripped binary. And it seems
> +# to require clang-built executables, not sure what the difference is that
> +# triggers the complete nullification.
> +
> +load_lib gdbserver-support.exp
> +
> +standard_testfile server.c
> +
> +if { [skip_gdbserver_tests] } {

untested "skipping gdbserver tests"?

Otherwise looks OK to me.