From 101110f6271ce956a049250c907bc960030577f8 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Wed, 21 Feb 2018 14:45:20 -0800 Subject: Kbuild: always define endianess in kconfig.h Build testing with LTO found a couple of files that get compiled differently depending on whether asm/byteorder.h gets included early enough or not. In particular, include/asm-generic/qrwlock_types.h is affected by this, but there are probably others as well. The symptom is a series of LTO link time warnings, including these: net/netlabel/netlabel_unlabeled.h:223: error: type of 'netlbl_unlhsh_add' does not match original declaration [-Werror=lto-type-mismatch] int netlbl_unlhsh_add(struct net *net, net/netlabel/netlabel_unlabeled.c:377: note: 'netlbl_unlhsh_add' was previously declared here include/net/ipv6.h:360: error: type of 'ipv6_renew_options_kern' does not match original declaration [-Werror=lto-type-mismatch] ipv6_renew_options_kern(struct sock *sk, net/ipv6/exthdrs.c:1162: note: 'ipv6_renew_options_kern' was previously declared here net/core/dev.c:761: note: 'dev_get_by_name_rcu' was previously declared here struct net_device *dev_get_by_name_rcu(struct net *net, const char *name) net/core/dev.c:761: note: code may be misoptimized unless -fno-strict-aliasing is used drivers/gpu/drm/i915/i915_drv.h:3377: error: type of 'i915_gem_object_set_to_wc_domain' does not match original declaration [-Werror=lto-type-mismatch] i915_gem_object_set_to_wc_domain(struct drm_i915_gem_object *obj, bool write); drivers/gpu/drm/i915/i915_gem.c:3639: note: 'i915_gem_object_set_to_wc_domain' was previously declared here include/linux/debugfs.h:92:9: error: type of 'debugfs_attr_read' does not match original declaration [-Werror=lto-type-mismatch] ssize_t debugfs_attr_read(struct file *file, char __user *buf, fs/debugfs/file.c:318: note: 'debugfs_attr_read' was previously declared here include/linux/rwlock_api_smp.h:30: error: type of '_raw_read_unlock' does not match original declaration [-Werror=lto-type-mismatch] void __lockfunc _raw_read_unlock(rwlock_t *lock) __releases(lock); kernel/locking/spinlock.c:246:26: note: '_raw_read_unlock' was previously declared here include/linux/fs.h:3308:5: error: type of 'simple_attr_open' does not match original declaration [-Werror=lto-type-mismatch] int simple_attr_open(struct inode *inode, struct file *file, fs/libfs.c:795: note: 'simple_attr_open' was previously declared here All of the above are caused by include/asm-generic/qrwlock_types.h failing to include asm/byteorder.h after commit e0d02285f16e ("locking/qrwlock: Use 'struct qrwlock' instead of 'struct __qrwlock'") in linux-4.15. Similar bugs may or may not exist in older kernels as well, but there is no easy way to test those with link-time optimizations, and kernels before 4.14 are harder to fix because they don't have Babu's patch series We had similar issues with CONFIG_ symbols in the past and ended up always including the configuration headers though linux/kconfig.h. This works around the issue through that same file, defining either __BIG_ENDIAN or __LITTLE_ENDIAN depending on CONFIG_CPU_BIG_ENDIAN, which is now always set on all architectures since commit 4c97a0c8fee3 ("arch: define CPU_BIG_ENDIAN for all fixed big endian archs"). Link: http://lkml.kernel.org/r/20180202154104.1522809-2-arnd@arndb.de Signed-off-by: Arnd Bergmann Cc: Babu Moger Cc: Andi Kleen Cc: Greg Kroah-Hartman Cc: Masahiro Yamada Cc: Nicolas Pitre Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Will Deacon Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/kconfig.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'include/linux/kconfig.h') diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h index fec5076eda91..cc8fa109cfa3 100644 --- a/include/linux/kconfig.h +++ b/include/linux/kconfig.h @@ -4,6 +4,12 @@ #include +#ifdef CONFIG_CPU_BIG_ENDIAN +#define __BIG_ENDIAN 4321 +#else +#define __LITTLE_ENDIAN 1234 +#endif + #define __ARG_PLACEHOLDER_1 0, #define __take_second_arg(__ignored, val, ...) val -- cgit v1.2.3 From 28128c61e08eaeced9cc8ec0e6b5d677b5b94690 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Thu, 22 Feb 2018 09:41:40 -0800 Subject: kconfig.h: Include compiler types to avoid missed struct attributes The header files for some structures could get included in such a way that struct attributes (specifically __randomize_layout from path.h) would be parsed as variable names instead of attributes. This could lead to some instances of a structure being unrandomized, causing nasty GPFs, etc. This patch makes sure the compiler_types.h header is included in kconfig.h so that we've always got types and struct attributes defined, since kconfig.h is included from the compiler command line. Reported-by: Patrick McLean Root-caused-by: Maciej S. Szmigiero Suggested-by: Linus Torvalds Tested-by: Maciej S. Szmigiero Fixes: 3859a271a003 ("randstruct: Mark various structs for randomization") Signed-off-by: Kees Cook Signed-off-by: Linus Torvalds --- include/linux/kconfig.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/linux/kconfig.h') diff --git a/include/linux/kconfig.h b/include/linux/kconfig.h index fec5076eda91..c5fd4ee776ba 100644 --- a/include/linux/kconfig.h +++ b/include/linux/kconfig.h @@ -64,4 +64,7 @@ */ #define IS_ENABLED(option) __or(IS_BUILTIN(option), IS_MODULE(option)) +/* Make sure we always have all types and struct attributes defined. */ +#include + #endif /* __LINUX_KCONFIG_H */ -- cgit v1.2.3