From a278f3d8191228212c553a5d4303fa603214b717 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Thu, 30 Jul 2020 19:42:44 -0700 Subject: [PATCH] tools, build: Propagate build failures from tools/build/Makefile.build The '&&' command seems to have a bad effect when $(cmd_$(1)) exits with non-zero effect: the command failure is masked (despite `set -e`) and all but the first command of $(dep-cmd) is executed (successfully, as they are mostly printfs), thus overall returning 0 in the end. This means in practice that despite compilation errors, tools's build Makefile will return success. We see this very reliably with libbpf's Makefile, which doesn't get compilation error propagated properly. This in turns causes issues with selftests build, as well as bpftool and other projects that rely on building libbpf. The fix is simple: don't use &&. Given `set -e`, we don't need to chain commands with &&. The shell will exit on first failure, giving desired behavior and propagating error properly. Fixes: 275e2d95591e ("tools build: Move dependency copy into function") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20200731024244.872574-1-andriin@fb.com --- tools/build/Build.include | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/tools/build/Build.include b/tools/build/Build.include index 9ec01f4454f9..585486e40995 100644 --- a/tools/build/Build.include +++ b/tools/build/Build.include @@ -74,7 +74,8 @@ dep-cmd = $(if $(wildcard $(fixdep)), # dependencies in the cmd file if_changed_dep = $(if $(strip $(any-prereq) $(arg-check)), \ @set -e; \ - $(echo-cmd) $(cmd_$(1)) && $(dep-cmd)) + $(echo-cmd) $(cmd_$(1)); \ + $(dep-cmd)) # if_changed - execute command if any prerequisite is newer than # target, or command line has changed