[lkml]   [2017]   [Nov]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH 17/21] lto, workaround: Disable LTO for BPF
From: Andi Kleen <>

Disable LTO for the BPF interpreter. This works around a gcc bug in the LTO
partitioner that partitions the jumptable used the BPF interpreter
into a different LTO unit. This in term causes assembler
errors because the jump table contains references to the
code labels in the original file.

gcc problem tracked in

Signed-off-by: Andi Kleen <>
kernel/bpf/Makefile | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/kernel/bpf/Makefile b/kernel/bpf/Makefile
index e691da0b3bab..409d4b6762ee 100644
--- a/kernel/bpf/Makefile
+++ b/kernel/bpf/Makefile
@@ -16,3 +16,8 @@ ifeq ($(CONFIG_PERF_EVENTS),y)
obj-$(CONFIG_BPF_SYSCALL) += stackmap.o
obj-$(CONFIG_CGROUP_BPF) += cgroup.o
+# various version of gcc have a LTO bug where the &&labels used in the
+# BPF interpreter can cause linker errors when spread incorrectly over
+# partitions. Disable LTO for BPF for now
 \ /
  Last update: 2017-11-27 22:37    [W:0.166 / U:1.900 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site