[PATCH AUTOSEL 5.1 141/219] x86/build: Add 'set -e' to mkcapflags.sh to delete broken capflags.c

[Sasha Levin]

From: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>

[ Upstream commit bc53d3d777f81385c1bb08b07bd1c06450ecc2c1 ]

Without 'set -e', shell scripts continue running even after any
error occurs. The missed 'set -e' is a typical bug in shell scripting.

For example, when a disk space shortage occurs while this script is
running, it actually ends up with generating a truncated capflags.c.

Yet, mkcapflags.sh continues running and exits with 0. So, the build
system assumes it has succeeded.

It will not be re-generated in the next invocation of Make since its
timestamp is newer than that of any of the source files.

Add 'set -e' so that any error in this script is caught and propagated
to the build system.

Since 9c2af1c7377a ("kbuild: add .DELETE_ON_ERROR special target"),
make automatically deletes the target on any failure. So, the broken
capflags.c will be deleted automatically.

Signed-off-by: Masahiro Yamada <yamada.masahiro@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: "H. Peter Anvin" <hpa@xxxxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Link: https://lkml.kernel.org/r/20190625072622.17679-1-yamada.masahiro@xxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/x86/kernel/cpu/mkcapflags.sh | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/kernel/cpu/mkcapflags.sh b/arch/x86/kernel/cpu/mkcapflags.sh
index d0dfb892c72f..aed45b8895d5 100644
--- a/arch/x86/kernel/cpu/mkcapflags.sh
+++ b/arch/x86/kernel/cpu/mkcapflags.sh
@@ -4,6 +4,8 @@
 # Generate the x86_cap/bug_flags[] arrays from include/asm/cpufeatures.h
 #
 
+set -e
+
 IN=$1
 OUT=$2
 
-- 
2.20.1