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Re: [PATCH] x86-64: Don't set GLRO(dl_platform) to NULL [BZ #22299]
On Thu, Oct 19, 2017 at 6:27 AM, Valery Reznic <valery_reznic@yahoo.com> wrote:
> I see.
>
> So what about [PATCH] x86-64: Don't set GLRO(dl_platform) to NULL [BZ
> #22299] - any chance to have it in glibc 2.27?
>
>
Tested on Haswell with and without --disable-tunables. This is the patch I am
going to check in.
--
H.J.
From a793aa32bb919aa6c1671e846a127424044c14f7 Mon Sep 17 00:00:00 2001
From: "H.J. Lu" <hjl.tools@gmail.com>
Date: Tue, 17 Oct 2017 08:27:09 -0700
Subject: [PATCH] x86-64: Don't set GLRO(dl_platform) to NULL [BZ #22299]
Since ld.so expands $PLATFORM with GLRO(dl_platform), don't set
GLRO(dl_platform) to NULL.
2017-10-17 Valery Reznic <valery_reznic@yahoo.com>
H.J. Lu <hongjiu.lu@intel.com>
[BZ #22299]
* sysdeps/x86/cpu-features.c (init_cpu_features): Don't set
GLRO(dl_platform) to NULL.
* sysdeps/x86_64/Makefile (tests): Add tst-platform-1.
(modules-names): Add tst-platformmod-1 and
x86_64/tst-platformmod-2.
(CFLAGS-tst-platform-1.c): New.
(CFLAGS-tst-platformmod-1.c): Likewise.
(CFLAGS-tst-platformmod-2.c): Likewise.
(LDFLAGS-tst-platformmod-2.so): Likewise.
($(objpfx)tst-platform-1): Likewise.
($(objpfx)tst-platform-1.out): Likewise.
(tst-platform-1-ENV): Likewise.
($(objpfx)x86_64/tst-platformmod-2.os): Likewise.
* sysdeps/x86_64/tst-platform-1.c: New file.
* sysdeps/x86_64/tst-platformmod-1.c: Likewise.
* sysdeps/x86_64/tst-platformmod-2.c: Likewise.
---
sysdeps/x86/cpu-features.c | 12 ++++++++----
sysdeps/x86_64/Makefile | 20 ++++++++++++++++++++
sysdeps/x86_64/tst-platform-1.c | 29 +++++++++++++++++++++++++++++
sysdeps/x86_64/tst-platformmod-1.c | 23 +++++++++++++++++++++++
sysdeps/x86_64/tst-platformmod-2.c | 23 +++++++++++++++++++++++
5 files changed, 103 insertions(+), 4 deletions(-)
create mode 100644 sysdeps/x86_64/tst-platform-1.c
create mode 100644 sysdeps/x86_64/tst-platformmod-1.c
create mode 100644 sysdeps/x86_64/tst-platformmod-2.c
diff --git a/sysdeps/x86/cpu-features.c b/sysdeps/x86/cpu-features.c
index c267f17b76..1b3cfcc7cd 100644
--- a/sysdeps/x86/cpu-features.c
+++ b/sysdeps/x86/cpu-features.c
@@ -335,7 +335,6 @@ no_cpuid:
#endif
/* Reuse dl_platform, dl_hwcap and dl_hwcap_mask for x86. */
- GLRO(dl_platform) = NULL;
#if !HAVE_TUNABLES && defined SHARED
/* The glibc.tune.hwcap_mask tunable is initialized already, so no need to do
this. */
@@ -346,13 +345,15 @@ no_cpuid:
GLRO(dl_hwcap) = HWCAP_X86_64;
if (cpu_features->kind == arch_kind_intel)
{
+ const char *platform = NULL;
+
if (CPU_FEATURES_ARCH_P (cpu_features, AVX512F_Usable)
&& CPU_FEATURES_CPU_P (cpu_features, AVX512CD))
{
if (CPU_FEATURES_CPU_P (cpu_features, AVX512ER))
{
if (CPU_FEATURES_CPU_P (cpu_features, AVX512PF))
- GLRO(dl_platform) = "xeon_phi";
+ platform = "xeon_phi";
}
else
{
@@ -363,7 +364,7 @@ no_cpuid:
}
}
- if (GLRO(dl_platform) == NULL
+ if (platform == NULL
&& CPU_FEATURES_ARCH_P (cpu_features, AVX2_Usable)
&& CPU_FEATURES_ARCH_P (cpu_features, FMA_Usable)
&& CPU_FEATURES_CPU_P (cpu_features, BMI1)
@@ -371,7 +372,10 @@ no_cpuid:
&& CPU_FEATURES_CPU_P (cpu_features, LZCNT)
&& CPU_FEATURES_CPU_P (cpu_features, MOVBE)
&& CPU_FEATURES_CPU_P (cpu_features, POPCNT))
- GLRO(dl_platform) = "haswell";
+ platform = "haswell";
+
+ if (platform)
+ GLRO(dl_platform) = platform;
}
#else
GLRO(dl_hwcap) = 0;
diff --git a/sysdeps/x86_64/Makefile b/sysdeps/x86_64/Makefile
index 1514805f4a..12d4737240 100644
--- a/sysdeps/x86_64/Makefile
+++ b/sysdeps/x86_64/Makefile
@@ -58,6 +58,21 @@ LDFLAGS-tst-x86_64mod-1.so = -Wl,-soname,tst-x86_64mod-1.so
$(objpfx)tst-x86_64-1: $(objpfx)x86_64/tst-x86_64mod-1.so
+ifneq (no,$(have-tunables))
+tests += tst-platform-1
+modules-names += tst-platformmod-1 x86_64/tst-platformmod-2
+CFLAGS-tst-platform-1.c = -mno-avx
+CFLAGS-tst-platformmod-1.c = -mno-avx
+CFLAGS-tst-platformmod-2.c = -mno-avx
+LDFLAGS-tst-platformmod-2.so = -Wl,-soname,tst-platformmod-2.so
+$(objpfx)tst-platform-1: $(objpfx)tst-platformmod-1.so
+$(objpfx)tst-platform-1.out: $(objpfx)x86_64/tst-platformmod-2.so
+# Turn off AVX512F_Usable and AVX2_Usable so that GLRO(dl_platform) is
+# always set to x86_64.
+tst-platform-1-ENV = LD_PRELOAD=$(objpfx)\$$PLATFORM/tst-platformmod-2.so \
+ GLIBC_TUNABLES=glibc.tune.hwcaps=-AVX512F_Usable,-AVX2_Usable
+endif
+
tests += tst-audit3 tst-audit4 tst-audit5 tst-audit6 tst-audit7 \
tst-audit10 tst-sse tst-avx tst-avx512
test-extras += tst-audit4-aux tst-audit10-aux \
@@ -141,3 +156,8 @@ do-tests-clean common-mostlyclean: tst-x86_64-1-clean
.PHONY: tst-x86_64-1-clean
tst-x86_64-1-clean:
-rm -rf $(objpfx)x86_64
+
+$(objpfx)x86_64/tst-platformmod-2.os: $(objpfx)tst-platformmod-2.os
+ $(make-target-directory)
+ rm -f $@
+ ln $< $@
diff --git a/sysdeps/x86_64/tst-platform-1.c b/sysdeps/x86_64/tst-platform-1.c
new file mode 100644
index 0000000000..76a02e4b6d
--- /dev/null
+++ b/sysdeps/x86_64/tst-platform-1.c
@@ -0,0 +1,29 @@
+/* Test PRELOAD with $PLATFORM.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+#include <stdlib.h>
+
+extern int preload (void);
+
+static int
+do_test (void)
+{
+ return preload () == 0x1234 ? EXIT_SUCCESS : EXIT_FAILURE;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/x86_64/tst-platformmod-1.c b/sysdeps/x86_64/tst-platformmod-1.c
new file mode 100644
index 0000000000..9ef5e2b5be
--- /dev/null
+++ b/sysdeps/x86_64/tst-platformmod-1.c
@@ -0,0 +1,23 @@
+/* Test PRELOAD with $PLATFORM.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+int
+preload (void)
+{
+ return 0;
+}
diff --git a/sysdeps/x86_64/tst-platformmod-2.c b/sysdeps/x86_64/tst-platformmod-2.c
new file mode 100644
index 0000000000..d0e5103892
--- /dev/null
+++ b/sysdeps/x86_64/tst-platformmod-2.c
@@ -0,0 +1,23 @@
+/* Test PRELOAD with $PLATFORM.
+ Copyright (C) 2017 Free Software Foundation, Inc.
+ This file is part of the GNU C Library.
+
+ The GNU C Library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 2.1 of the License, or (at your option) any later version.
+
+ The GNU C Library 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
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with the GNU C Library; if not, see
+ <http://www.gnu.org/licenses/>. */
+
+int
+preload (void)
+{
+ return 0x1234;
+}
--
2.13.6