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: sta...@dpdk.org Signed-off-by: Ferruh Yigit <ferruh.yi...@intel.com> Acked-by: Bruce Richardson <bruce.richard...@intel.com> --- v3: * merge if conditions in meson v2: * Release notes "Known Issues" section updated --- config/x86/meson.build | 4 ++++ doc/guides/rel_notes/release_19_05.rst | 6 ++++++ mk/toolchain/gcc/rte.toolchain-compat.mk | 9 ++++++++- 3 files changed, 18 insertions(+), 1 deletion(-) diff --git a/config/x86/meson.build b/config/x86/meson.build index ca4d12506..0a7bed75e 100644 --- a/config/x86/meson.build +++ b/config/x86/meson.build @@ -10,6 +10,10 @@ if not is_windows message('Binutils 2.30 detected, disabling AVX512 support as workaround for bug #97') endif 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 # we require SSE4.2 for DPDK 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 @@ -368,6 +368,12 @@ Known Issues Also, make sure to start the actual text at the margin. ========================================================= +* **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.** There are currently no cryptodev software PMDs available which implement 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 -- 2.20.1
