Do we really want to quote to this level? This message has 11 levels of
quotes, the most I have ever seen. If everyone does this, the whole
thread is in every message and that seems unnecessary. I don't know if
there are gcc guidelines on this???
On 3/18/2015 9:59 AM, Ilya Enkovich wrote:
2015-03-18 16:52 GMT+03:00 H.J. Lu <hjl.to...@gmail.com>:
On Wed, Mar 18, 2015 at 6:41 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
2015-03-18 16:31 GMT+03:00 H.J. Lu <hjl.to...@gmail.com>:
On Wed, Mar 18, 2015 at 6:24 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
2015-03-18 15:42 GMT+03:00 Richard Biener <richard.guent...@gmail.com>:
On Wed, Mar 18, 2015 at 1:25 PM, H.J. Lu <hjl.to...@gmail.com> wrote:
On Wed, Mar 18, 2015 at 5:13 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
2015-03-18 15:08 GMT+03:00 H.J. Lu <hjl.to...@gmail.com>:
On Wed, Mar 18, 2015 at 5:05 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
2015-03-18 15:02 GMT+03:00 H.J. Lu <hjl.to...@gmail.com>:
On Wed, Mar 18, 2015 at 4:56 AM, Ilya Enkovich <enkovich....@gmail.com> wrote:
Hi,
This patch fixes PR target/65444 by passing '-z bndplt' to linker when
appropriate. Bootstrapped and tested on x86_64-unknown-linux-gnu. Will commit
it to trunk in a couple of days if no objections arise.
Thanks,
Ilya
--
gcc/
2015-03-18 Ilya Enkovich <ilya.enkov...@intel.com>
PR driver/65444
* config/i386/linux-common.h (MPX_SPEC): New.
(CHKP_SPEC): Add MPX_SPEC.
libmpx/
2015-03-18 Ilya Enkovich <ilya.enkov...@intel.com>
PR driver/65444
* configure.ac: Add check for '-z bndplt' support
by linker. Add link_mpx output variable.
* libmpx.spec.in (link_mpx): New.
* configure: Regenerate.
diff --git a/gcc/config/i386/linux-common.h b/gcc/config/i386/linux-common.h
index 9c6560b..dd79ec6 100644
--- a/gcc/config/i386/linux-common.h
+++ b/gcc/config/i386/linux-common.h
@@ -59,6 +59,11 @@ along with GCC; see the file COPYING3. If not see
%:include(libmpx.spec)%(link_libmpx)"
#endif
+#ifndef MPX_SPEC
+#define MPX_SPEC "\
+ %{mmpx:%{fcheck-pointer-bounds:%{!static:%:include(libmpx.spec)%(link_mpx)}}}"
+#endif
+
#ifndef LIBMPX_SPEC
#if defined(HAVE_LD_STATIC_DYNAMIC)
#define LIBMPX_SPEC "\
@@ -89,5 +94,5 @@ along with GCC; see the file COPYING3. If not see
#ifndef CHKP_SPEC
#define CHKP_SPEC "\
-%{!nostdlib:%{!nodefaultlibs:" LIBMPX_SPEC LIBMPXWRAPPERS_SPEC "}}"
+%{!nostdlib:%{!nodefaultlibs:" LIBMPX_SPEC LIBMPXWRAPPERS_SPEC "}}" MPX_SPEC
#endif
diff --git a/libmpx/configure.ac b/libmpx/configure.ac
index fe0d3f2..3f8b50f 100644
--- a/libmpx/configure.ac
+++ b/libmpx/configure.ac
@@ -40,7 +40,18 @@ AC_MSG_RESULT($LIBMPX_SUPPORTED)
AM_CONDITIONAL(LIBMPX_SUPPORTED, [test "x$LIBMPX_SUPPORTED" = "xyes"])
link_libmpx="-lpthread"
+link_mpx=""
+AC_MSG_CHECKING([whether ld accepts -z bndplt])
+echo "int main() {};" > conftest.c
+if AC_TRY_COMMAND([${CC} ${CFLAGS} -Wl,-z,bndplt -o conftest conftest.c
1>&AS_MESSAGE_LOG_FD])
+then
+ AC_MSG_RESULT([yes])
+ link_mpx="$link_mpx -z bndplt"
+else
+ AC_MSG_RESULT([no])
+fi
AC_SUBST(link_libmpx)
+AC_SUBST(link_mpx)
Without -z bndplt, MPX won't work correctly. We should always pass -z bndplt
to linker. If linker doesn't support it, ld will issue a warning, not
error and users
will know their linker is too old. When they update linker, they don't have to
rebuild GCC.
If ld issues a warning instead of an error, then configure test passes
and we pass '-z bndplt' to linker.
Can you verify it with an older linker? The unknown XXX in -z XXX is always
warned and ignored in Linux linker. If testing it on Linux always passes,
it is useless.
Old ld issues a warning:
ld: warning: -z bndplt ignored.
Does configure test pass?
But gold issues an error:
ld.gold: bndplt: unknown -z option
ld.gold: use the --help option for usage information
If gold is used, MPX won't work. What should we do here?
Should we hardcode -fuse-ld=bfd for MPX?
Is MPX disabled when the host linker is gold and gld isn't available?
No. You may use MPX with gold and old ld but you would loose passed
bounds when make a call via plt.
If gold is default linker, the configure test will fail and we never pass
-z bndplt to linker even if ld.bfd is available and ld.gold is fixed later.
I'd rather always pass -z bndplt to ld.
If gold is used and it doesn't support '-z bndplt' then it doesn't
mean user can't use MPX.
They can use -fuse-ld=bfd to select bfd linker if gold fails to generate
proper MPX binary.
Which is a weird thing to do just to have a warning instead of an
error. You don't guarantee MPX PLT generation by always passing '-z
bndplt' but remove an opportunity to use gold at all. With current
check you may use any linker and manually provide additional options
if you want to.
Ilya
--
H.J.
