[dpdk-stable] patch 'build: fix crash by disabling AVX512 with binutils 2.31' has been queued to LTS release 18.11.2

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.2

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 05/13/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Queued patches are on a temporary branch at:
https://github.com/kevintraynor/dpdk-stable-queue

This queued commit can be viewed at:
https://github.com/kevintraynor/dpdk-stable-queue/commit/f5555cc6375884da8bc0094fb733b3448cf8948d

Thanks.

Kevin Traynor

---
>From f5555cc6375884da8bc0094fb733b3448cf8948d Mon Sep 17 00:00:00 2001
From: Ferruh Yigit <ferruh.yigit at intel.com>
Date: Thu, 2 May 2019 14:35:26 +0100
Subject: [PATCH] build: fix crash by disabling AVX512 with binutils 2.31

[ upstream commit e19c6de3f2f12d0f49bdf9e787b3f43612c1df3c ]

On Skylake platform, with native build, KNI kernel module crashes
because of the corrupted values passed to kernel module.

The corruption occurs because the userspace kni library works
unexpectedly. Compiler [1] is using AVX512 instructions and generated
binary is wrong [2].

It turned around gcc does its job correct, but gas is generating binary
wrong. And expected binutils 2.30, 2.31 & 2.31.1 are affected. Issue has
been fixed in binutils 2.32 with:
Commit x86: don't mistakenly scale non-8-bit displacements

AVX512 was already disabled with bintuils 2.30 [3], extending it to
2.31 & 2.31.1 too.

[1] gcc (GCC) 8.3.1 20190223 (Red Hat 8.3.1-2)

[2] gcc bug: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90028

[3] Bugzilla ID 97 has the details.

Bugzilla ID: 249

Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
Acked-by: Bruce Richardson <bruce.richardson at intel.com>
---
 config/x86/meson.build                   | 4 ++++
 mk/toolchain/gcc/rte.toolchain-compat.mk | 9 ++++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/config/x86/meson.build b/config/x86/meson.build
index c92ffec6f..ae92f86a2 100644
--- a/config/x86/meson.build
+++ b/config/x86/meson.build
@@ -9,4 +9,8 @@ if ldver.contains('2.30')
 		message('Binutils 2.30 detected, disabling AVX512 support as workaround for bug #97')
 	endif
+	if ldver.contains('2.31') and cc.has_argument('-mno-avx512f')
+		machine_args += '-mno-avx512f'
+		message('Binutils 2.31 detected, disabling AVX512 support as workaround for bug #249')
+	endif
 endif
 
diff --git a/mk/toolchain/gcc/rte.toolchain-compat.mk b/mk/toolchain/gcc/rte.toolchain-compat.mk
index df71e4a8b..ea40a11c0 100644
--- a/mk/toolchain/gcc/rte.toolchain-compat.mk
+++ b/mk/toolchain/gcc/rte.toolchain-compat.mk
@@ -28,5 +28,12 @@ FORCE_DISABLE_AVX512 := y
 # print warning only once for librte_eal
 ifneq ($(filter %librte_eal,$(CURDIR)),)
-$(warning AVX512 support disabled because of ld 2.30. See Bug 97)
+$(warning AVX512 support disabled because of binutils 2.30. See Bug 97)
+endif
+endif
+ifneq ($(filter 2.31%,$(LD_VERSION)),)
+FORCE_DISABLE_AVX512 := y
+# print warning only once for librte_eal
+ifneq ($(filter %librte_eal,$(CURDIR)),)
+$(warning AVX512 support disabled because of binutils 2.31. See Bug 249)
 endif
 endif
-- 
2.20.1

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-05-08 11:05:08.335322113 +0100
+++ 0051-build-fix-crash-by-disabling-AVX512-with-binutils-2..patch	2019-05-08 11:05:05.860932113 +0100
@@ -1 +1 @@
-From e19c6de3f2f12d0f49bdf9e787b3f43612c1df3c Mon Sep 17 00:00:00 2001
+From f5555cc6375884da8bc0094fb733b3448cf8948d Mon Sep 17 00:00:00 2001
@@ -5,0 +6,2 @@
+[ upstream commit e19c6de3f2f12d0f49bdf9e787b3f43612c1df3c ]
+
@@ -28 +29,0 @@
-Cc: stable at dpdk.org
@@ -34 +34,0 @@
- doc/guides/rel_notes/release_19_05.rst   | 6 ++++++
@@ -36 +36 @@
- 3 files changed, 18 insertions(+), 1 deletion(-)
+ 2 files changed, 12 insertions(+), 1 deletion(-)
@@ -39 +39 @@
-index ca4d12506..0a7bed75e 100644
+index c92ffec6f..ae92f86a2 100644
@@ -42,2 +42,2 @@
-@@ -11,4 +11,8 @@ if not is_windows
- 		endif
+@@ -9,4 +9,8 @@ if ldver.contains('2.30')
+ 		message('Binutils 2.30 detected, disabling AVX512 support as workaround for bug #97')
@@ -50,15 +49,0 @@
- 
-diff --git a/doc/guides/rel_notes/release_19_05.rst b/doc/guides/rel_notes/release_19_05.rst
-index 439725c8a..468e32539 100644
---- a/doc/guides/rel_notes/release_19_05.rst
-+++ b/doc/guides/rel_notes/release_19_05.rst
-@@ -369,4 +369,10 @@ Known Issues
-    =========================================================
- 
-+* **On x86 platforms, AVX512 support is disabled with binutils 2.31**
-+
-+  Because a defect in binutils 2.31 AVX512 support is disabled.
-+  DPDK defect: https://bugs.dpdk.org/show_bug.cgi?id=249
-+  GCC defect: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90028
-+
- * **No software AES-XTS implementation.**