From c2c5dc84ac51da90cadcb12554c69bdd5ac7aeeb Mon Sep 17 00:00:00 2001 From: Arvind Sankar Date: Fri, 13 Nov 2020 22:51:59 -0800 Subject: compiler.h: fix barrier_data() on clang commit 3347acc6fcd4ee71ad18a9ff9d9dac176b517329 upstream. Commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") neglected to copy barrier_data() from compiler-gcc.h into compiler-clang.h. The definition in compiler-gcc.h was really to work around clang's more aggressive optimization, so this broke barrier_data() on clang, and consequently memzero_explicit() as well. For example, this results in at least the memzero_explicit() call in lib/crypto/sha256.c:sha256_transform() being optimized away by clang. Fix this by moving the definition of barrier_data() into compiler.h. Also move the gcc/clang definition of barrier() into compiler.h, __memory_barrier() is icc-specific (and barrier() is already defined using it in compiler-intel.h) and doesn't belong in compiler.h. [rdunlap@infradead.org: fix ALPHA builds when SMP is not enabled] Link: https://lkml.kernel.org/r/20201101231835.4589-1-rdunlap@infradead.org Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") Signed-off-by: Arvind Sankar Signed-off-by: Randy Dunlap Signed-off-by: Andrew Morton Tested-by: Nick Desaulniers Reviewed-by: Nick Desaulniers Reviewed-by: Kees Cook Cc: Link: https://lkml.kernel.org/r/20201014212631.207844-1-nivedita@alum.mit.edu Signed-off-by: Linus Torvalds [nd: backport to account for missing commit e506ea451254a ("compiler.h: Split {READ,WRITE}_ONCE definitions out into rwonce.h") commit d08b9f0ca6605 ("scs: Add support for Clang's Shadow Call Stack (SCS)")] Signed-off-by: Nick Desaulniers Signed-off-by: Greg Kroah-Hartman --- include/linux/compiler-clang.h | 6 ------ 1 file changed, 6 deletions(-) (limited to 'include/linux/compiler-clang.h') diff --git a/include/linux/compiler-clang.h b/include/linux/compiler-clang.h index 333a6695a918..0e06df20928c 100644 --- a/include/linux/compiler-clang.h +++ b/include/linux/compiler-clang.h @@ -36,9 +36,3 @@ __has_builtin(__builtin_sub_overflow) #define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1 #endif - -/* The following are for compatibility with GCC, from compiler-gcc.h, - * and may be redefined here because they should not be shared with other - * compilers, like ICC. - */ -#define barrier() __asm__ __volatile__("" : : : "memory") -- cgit v1.2.3