Commit e00d8880 authored by Masahiro Yamada's avatar Masahiro Yamada
Browse files

kbuild: mark prepare0 as PHONY to fix external module build

Commit c3ff2a51 ("powerpc/32: add stack protector support")
caused kernel panic on PowerPC when an external module is used with
CONFIG_STACKPROTECTOR because the 'prepare' target was not executed
for the external module build.

Commit e07db28e ("kbuild: fix single target build for external
module") turned it into a build error because the 'prepare' target is
now executed but the 'prepare0' target is missing for the external
module build.

External module on arm/arm64 with CONFIG_STACKPROTECTOR_PER_TASK is
also broken in the same way.

Move 'PHONY += prepare0' to the common place. GNU Make is fine with
missing rule for phony targets. I also removed the comment which is
wrong irrespective of this commit.

I minimize the change so it can be easily backported to 4.20.x

To fix v4.20, please backport e07db28e ("kbuild: fix single target
build for external module"), and then this commit.

Fixes: e07db28e ("kbuild: fix single target build for external module")
Fixes: c3ff2a51 ("powerpc/32: add stack protector support")
Fixes: 189af465 ("ARM: smp: add support for per-task stack canaries")
Fixes: 0a1213fa

 ("arm64: enable per-task stack canaries")
Cc: linux-stable <> # v4.20
Reported-by: default avatarSamuel Holland <>
Reported-by: default avatarAlexey Kardashevskiy <>
Signed-off-by: default avatarMasahiro Yamada <>
Acked-by: default avatarArd Biesheuvel <>
Tested-by: default avatarAlexey Kardashevskiy <>
parent 1b504a7b
......@@ -955,6 +955,7 @@ ifdef CONFIG_STACK_VALIDATION
PHONY += prepare0
ifeq ($(KBUILD_EXTMOD),)
core-y += kernel/ certs/ mm/ fs/ ipc/ security/ crypto/ block/
......@@ -1061,8 +1062,7 @@ scripts: scripts_basic scripts_dtc
# archprepare is used in arch Makefiles and when processed asm symlink,
# version.h and scripts_basic is processed / created.
# Listed in dependency order
PHONY += prepare archprepare prepare0 prepare1 prepare2 prepare3
PHONY += prepare archprepare prepare1 prepare2 prepare3
# prepare3 is used to check if we are building in a separate output directory,
# and if so do:
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