Commit c3ff2a5193fa ("powerpc/32: add stack protector support") caused kernel panic on PowerPC if an external module is used with CONFIG_STACKPROTECTOR because the 'prepare' target was not executed for the external module build.
Commit e07db28eea38 ("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. Make is fine with missing rule for phony targets.
I minimize the change so it can be easily backported to 4.20.x
To fix v4.20 for external modules of PowerPC, please backport e07db28eea38 ("kbuild: fix single target build for external module"), and then this commit.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=201891 Fixes: e07db28eea38 ("kbuild: fix single target build for external module") Fixes: c3ff2a5193fa ("powerpc/32: add stack protector support") Fixes: 189af4657186 ("ARM: smp: add support for per-task stack canaries") Fixes: 0a1213fa7432 ("arm64: enable per-task stack canaries") Cc: linux-stable stable@vger.kernel.org # v4.20 Reported-by: Samuel Holland samuel@sholland.org Reported-by: Alexey Kardashevskiy aik@ozlabs.ru Signed-off-by: Masahiro Yamada yamada.masahiro@socionext.com ---
Makefile | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/Makefile b/Makefile index 499b968..789b332 100644 --- a/Makefile +++ b/Makefile @@ -955,6 +955,7 @@ ifdef CONFIG_STACK_VALIDATION endif endif
+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: