path: root/scripts
diff options
authorAndrii Nakryiko <>2021-06-28 19:41:34 -0700
committerLinus Torvalds <>2021-06-29 10:53:54 -0700
commita0b8200d06ad6450c179407baa5f0f52f8cfcc97 (patch)
treea9d75ffcd32c3899787ce5753a22e06d8f4e6b40 /scripts
parent9660ecaa79ce5c068aa3138ca7e29a9402f284ed (diff)
kbuild: skip per-CPU BTF generation for pahole v1.18-v1.21
Commit "mm/page_alloc: convert per-cpu list protection to local_lock" will introduce a zero-sized per-CPU variable, which causes pahole to generate invalid BTF. Only pahole versions 1.18 through 1.21 are impacted, as before 1.18 pahole doesn't know anything about per-CPU variables, and 1.22 contains the proper fix for the issue. Luckily, pahole 1.18 got --skip_encoding_btf_vars option disabling BTF generation for per-CPU variables in anticipation of some unanticipated problems. So use this escape hatch to disable per-CPU var BTF info on those problematic pahole versions. Users relying on availability of per-CPU var BTFs would need to upgrade to pahole 1.22+, but everyone won't notice any regressions. Link: Signed-off-by: Andrii Nakryiko <> Acked-by: Mel Gorman <> Cc: Arnaldo Carvalho de Melo <> Cc: Hao Luo <> Cc: Michal Suchanek <> Cc: Jiri Olsa <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
Diffstat (limited to 'scripts')
1 files changed, 4 insertions, 0 deletions
diff --git a/scripts/ b/scripts/
index 0e0f6466b18d..475faa15854e 100755
--- a/scripts/
+++ b/scripts/
@@ -235,6 +235,10 @@ gen_btf()
vmlinux_link ${1}
+ if [ "${pahole_ver}" -ge "118" ] && [ "${pahole_ver}" -le "121" ]; then
+ # pahole 1.18 through 1.21 can't handle zero-sized per-CPU vars
+ extra_paholeopt="${extra_paholeopt} --skip_encoding_btf_vars"
+ fi
if [ "${pahole_ver}" -ge "121" ]; then
extra_paholeopt="${extra_paholeopt} --btf_gen_floats"