[PATCH] Pass -Wl, --no-error-execstack for tests where -Wl, -z, execstack is used [PR32717]

[Adhemerval Zanella Netto]

On 18/02/25 16:32, Sam James wrote:
> When GNU Binutils is configured with --enable-error-execstack=yes, a handful
> of our tests which rely on -Wl,-z,execstack fail. Pass --Wl,--no-error-execstack
> to override the behaviour and get a warning instead.
> 
> Bug: https://sourceware.org/PR32717

LGTM, thanks.

Reviewed-by: Adhemerval Zanella  <adhemerval.zanella@linaro.org>

> ---
> Tested on x86_64-pc-linux-gnu.
> 
>  config.make.in |  1 +
>  configure      | 35 +++++++++++++++++++++++++++++++++++
>  configure.ac   |  4 ++++
>  elf/Makefile   |  6 ++++++
>  nptl/Makefile  |  3 +++
>  5 files changed, 49 insertions(+)
> 
> diff --git a/config.make.in b/config.make.in
> index 36096881b7..59897eaec2 100644
> --- a/config.make.in
> +++ b/config.make.in
> @@ -53,6 +53,7 @@ c++-bits-std_abs-h = @CXX_BITS_STD_ABS_H@
>  enable-werror = @enable_werror@
>  
>  have-z-execstack = @libc_cv_z_execstack@
> +have-no-error-execstack = @libc_cv_no_error_execstack@
>  have-protected-data = @libc_cv_protected_data@
>  have-insert = @libc_cv_insert@
>  have-glob-dat-reloc = @libc_cv_has_glob_dat@
> diff --git a/configure b/configure
> index eb8abd0054..3d43b7a44a 100755
> --- a/configure
> +++ b/configure
> @@ -659,6 +659,7 @@ libc_cv_has_glob_dat
>  libc_cv_fpie
>  libc_cv_test_static_pie
>  libc_cv_z_execstack
> +libc_cv_no_error_execstack
>  ASFLAGS_config
>  libc_cv_cc_with_libunwind
>  libc_cv_insert
> @@ -7114,6 +7115,40 @@ if test $libc_cv_as_noexecstack = yes; then
>  fi
>  
>  
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for linker that supports --no-error-execstack" >&5
> +printf %s "checking for linker that supports --no-error-execstack... " >&6; }
> +libc_linker_feature=no
> +cat > conftest.c <<EOF
> +int _start (void) { return 42; }
> +EOF
> +if { ac_try='${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp
> +		  -Wl,-no-error-execstack -nostdlib -nostartfiles
> +		  -fPIC -shared -o conftest.so conftest.c
> +		  1>&5'
> +  { { eval echo "\"\$as_me\":${as_lineno-$LINENO}: \"$ac_try\""; } >&5
> +  (eval $ac_try) 2>&5
> +  ac_status=$?
> +  printf "%s\n" "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
> +  test $ac_status = 0; }; }
> +then
> +  if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS $no_ssp -Wl,-no-error-execstack -nostdlib \
> +      -nostartfiles -fPIC -shared -o conftest.so conftest.c 2>&1 \
> +      | grep "warning: --no-error-execstack ignored" > /dev/null 2>&1; then
> +    true
> +  else
> +    libc_linker_feature=yes
> +  fi
> +fi
> +rm -f conftest*
> +if test $libc_linker_feature = yes; then
> +  libc_cv_no_error_execstack=yes
> +else
> +  libc_cv_no_error_execstack=no
> +fi
> +{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $libc_linker_feature" >&5
> +printf "%s\n" "$libc_linker_feature" >&6; }
> +
> +
>  { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for linker that supports -z execstack" >&5
>  printf %s "checking for linker that supports -z execstack... " >&6; }
>  libc_linker_feature=no
> diff --git a/configure.ac b/configure.ac
> index 050bfa65e3..f16dbe598f 100644
> --- a/configure.ac
> +++ b/configure.ac
> @@ -1318,6 +1318,10 @@ if test $libc_cv_as_noexecstack = yes; then
>  fi
>  AC_SUBST(ASFLAGS_config)
>  
> +LIBC_LINKER_FEATURE([--no-error-execstack], [-Wl,-no-error-execstack],
> +		    [libc_cv_no_error_execstack=yes], [libc_cv_no_error_execstack=no])
> +AC_SUBST(libc_cv_no_error_execstack)
> +
>  LIBC_LINKER_FEATURE([-z execstack], [-Wl,-z,execstack],
>  		    [libc_cv_z_execstack=yes], [libc_cv_z_execstack=no])
>  AC_SUBST(libc_cv_z_execstack)
> diff --git a/elf/Makefile b/elf/Makefile
> index 1ea0e7037e..41f01b5c89 100644
> --- a/elf/Makefile
> +++ b/elf/Makefile
> @@ -1990,6 +1990,9 @@ $(objpfx)tst-execstack.out: $(objpfx)tst-execstack-mod.so
>  CPPFLAGS-tst-execstack.c += -DUSE_PTHREADS=0
>  LDFLAGS-tst-execstack = -Wl,-z,noexecstack
>  LDFLAGS-tst-execstack-mod.so = -Wl,-z,execstack
> +ifeq ($(have-no-error-execstack),yes)
> +LDFLAGS-tst-execstack-mod.so += -Wl,--no-error-execstack
> +endif
>  
>  $(objpfx)tst-execstack-needed: $(objpfx)tst-execstack-mod.so
>  LDFLAGS-tst-execstack-needed = -Wl,-z,noexecstack
> @@ -1999,6 +2002,9 @@ CFLAGS-tst-execstack-prog.c += -Wno-trampolines
>  CFLAGS-tst-execstack-mod.c += -Wno-trampolines
>  
>  LDFLAGS-tst-execstack-prog-static = -Wl,-z,execstack
> +ifeq ($(have-no-error-execstack),yes)
> +LDFLAGS-tst-execstack-prog-static += -Wl,--no-error-execstack
> +endif
>  CFLAGS-tst-execstack-prog-static.c += -Wno-trampolines
>  
>  ifeq (yes,$(build-hardcoded-path-in-tests))
> diff --git a/nptl/Makefile b/nptl/Makefile
> index 66caa7ab93..f70d1e55bd 100644
> --- a/nptl/Makefile
> +++ b/nptl/Makefile
> @@ -702,6 +702,9 @@ $(objpfx)tst-execstack-threads.out: $(objpfx)tst-execstack-threads-mod.so
>  LDFLAGS-tst-execstack-threads = -Wl,-z,noexecstack
>  LDFLAGS-tst-execstack-threads-mod.so = -Wl,-z,execstack
>  CFLAGS-tst-execstack-threads-mod.c += -Wno-trampolines
> +ifeq ($(have-no-error-execstack),yes)
> +LDFLAGS-tst-execstack-threads-mod.so += -Wl,--no-error-execstack
> +endif
>  
>  tst-stackguard1-ARGS = --command "$(host-test-program-cmd) --child"
>  tst-stackguard1-static-ARGS = --command "$(objpfx)tst-stackguard1-static --child"