[2/2] build: fix crash by disabling AVX512 with binutils 2.31

Message ID 20190410140058.26782-2-ferruh.yigit@intel.com (mailing list archive)
State Superseded, archived
Delegated to: Thomas Monjalon
Headers
Series [1/2] build: fix meson binutils workaround |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Ferruh Yigit April 10, 2019, 2 p.m. UTC
  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
Cc: stable@dpdk.org

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
---
 config/x86/meson.build                   | 6 ++++++
 mk/toolchain/gcc/rte.toolchain-compat.mk | 9 ++++++++-
 2 files changed, 14 insertions(+), 1 deletion(-)
  

Patch

diff --git a/config/x86/meson.build b/config/x86/meson.build
index 692aebe7a..9e9d5dc8c 100644
--- a/config/x86/meson.build
+++ b/config/x86/meson.build
@@ -10,6 +10,12 @@  if host_machine.system() != 'windows'
 			message('Binutils 2.30 detected, disabling AVX512 support as workaround for bug #97')
 		endif
 	endif
+	if ldver.contains('2.31')
+		if cc.has_argument('-mno-avx512f')
+			machine_args += '-mno-avx512f'
+			message('Binutils 2.31 detected, disabling AVX512 support as workaround for bug #249')
+		endif
+	endif
 endif
 
 # we require SSE4.2 for DPDK
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
@@ -27,7 +27,14 @@  ifneq ($(filter 2.30%,$(LD_VERSION)),)
 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
 endif