From: Romain Naour Date: Sat, 2 Jun 2018 14:34:07 +0000 (+0200) Subject: linux: disable attribute alias with gcc >= 8.1 X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=9a50447b5d4b2ab0162e3235395ab9a4c8a647d5;p=buildroot.git linux: disable attribute alias with gcc >= 8.1 gcc-8 started warning about function aliases that have a non-matching prototype. This seems rather useful in general, but it causes tons of warnings in the Linux kernel, where we rely on abusing those aliases for system call entry points, in order to sanitze the arguments passed from user space in registers. See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82435 Disable the attribute-alias warning introduced by gcc-8 by adding -Wno-attribute-alias to KCFLAGS. Signed-off-by: Romain Naour Cc: Thomas Petazzoni Signed-off-by: Thomas Petazzoni --- diff --git a/linux/linux.mk b/linux/linux.mk index 7f4c916671..7527b11673 100644 --- a/linux/linux.mk +++ b/linux/linux.mk @@ -121,6 +121,16 @@ LINUX_MAKE_ENV += \ KBUILD_BUILD_TIMESTAMP="$(shell LC_ALL=C date -d @$(SOURCE_DATE_EPOCH))" endif +# gcc-8 started warning about function aliases that have a +# non-matching prototype. This seems rather useful in general, but it +# causes tons of warnings in the Linux kernel, where we rely on +# abusing those aliases for system call entry points, in order to +# sanitize the arguments passed from user space in registers. +# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82435 +ifeq ($(BR2_TOOLCHAIN_GCC_AT_LEAST_8),y) +LINUX_MAKE_ENV += KCFLAGS=-Wno-attribute-alias +endif + # Get the real Linux version, which tells us where kernel modules are # going to be installed in the target filesystem. LINUX_VERSION_PROBED = `$(MAKE) $(LINUX_MAKE_FLAGS) -C $(LINUX_DIR) --no-print-directory -s kernelrelease 2>/dev/null`