From 6cb9e96fe61956118ed83fd16e89e7f24f01a06b Mon Sep 17 00:00:00 2001
From: Chris Down <chris@chrisdown.name>
Date: Wed, 22 Jan 2020 00:01:10 +0000
Subject: [PATCH] bpf, btf: Always output invariant hit in pahole DWARF to BTF
 transform

commit 2a67a6ccb01f21b854715d86ff6432a18b97adb3 upstream.

When trying to compile with CONFIG_DEBUG_INFO_BTF enabled, I got this
error:

    % make -s
    Failed to generate BTF for vmlinux
    Try to disable CONFIG_DEBUG_INFO_BTF
    make[3]: *** [vmlinux] Error 1

Compiling again without -s shows the true error (that pahole is
missing), but since this is fatal, we should show the error
unconditionally on stderr as well, not silence it using the `info`
function. With this patch:

    % make -s
    BTF: .tmp_vmlinux.btf: pahole (pahole) is not available
    Failed to generate BTF for vmlinux
    Try to disable CONFIG_DEBUG_INFO_BTF
    make[3]: *** [vmlinux] Error 1

Signed-off-by: Chris Down <chris@chrisdown.name>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200122000110.GA310073@chrisdown.name
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/scripts/link-vmlinux.sh b/scripts/link-vmlinux.sh
old mode 100755
new mode 100644
index a7124f895b24..307574be4e22
--- a/scripts/link-vmlinux.sh
+++ b/scripts/link-vmlinux.sh
@@ -97,13 +97,13 @@ gen_btf()
 	local pahole_ver;
 
 	if ! [ -x "$(command -v ${PAHOLE})" ]; then
-		info "BTF" "${1}: pahole (${PAHOLE}) is not available"
+		echo >&2 "BTF: ${1}: pahole (${PAHOLE}) is not available"
 		return 0
 	fi
 
 	pahole_ver=$(${PAHOLE} --version | sed -E 's/v([0-9]+)\.([0-9]+)/\1\2/')
 	if [ "${pahole_ver}" -lt "113" ]; then
-		info "BTF" "${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13"
+		echo >&2 "BTF: ${1}: pahole version $(${PAHOLE} --version) is too old, need at least v1.13"
 		return 0
 	fi
 
-- 
2.7.4