Files
kernel_xiaomi_sm8250/include/linux/compiler-clang.h
Arvind Sankar b207caff41 compiler.h: fix barrier_data() on clang
commit 3347acc6fcd4ee71ad18a9ff9d9dac176b517329 upstream.

Commit 815f0ddb34 ("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: 815f0ddb34 ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")
Signed-off-by: Arvind Sankar <nivedita@alum.mit.edu>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Link: https://lkml.kernel.org/r/20201014212631.207844-1-nivedita@alum.mit.edu
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[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)")
  commit a3f8a30f3f00 ("Compiler Attributes: use feature checks instead of version checks")]
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-12-30 11:25:40 +01:00

45 lines
1.6 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_TYPES_H
#error "Please don't include <linux/compiler-clang.h> directly, include <linux/compiler.h> instead."
#endif
/* Compiler specific definitions for Clang compiler */
#define uninitialized_var(x) x = *(&(x))
/* same as gcc, this was present in clang-2.6 so we can assume it works
* with any version that can compile the kernel
*/
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
/* all clang versions usable with the kernel support KASAN ABI version 5 */
#define KASAN_ABI_VERSION 5
/* emulate gcc's __SANITIZE_ADDRESS__ flag */
#if __has_feature(address_sanitizer)
#define __SANITIZE_ADDRESS__
#endif
#define __no_sanitize_address __attribute__((no_sanitize("address")))
/*
* Not all versions of clang implement the the type-generic versions
* of the builtin overflow checkers. Fortunately, clang implements
* __has_builtin allowing us to avoid awkward version
* checks. Unfortunately, we don't know which version of gcc clang
* pretends to be, so the macro may or may not be defined.
*/
#if __has_builtin(__builtin_mul_overflow) && \
__has_builtin(__builtin_add_overflow) && \
__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 __must_be_array(a) BUILD_BUG_ON_ZERO(__same_type((a), &(a)[0]))
#define __assume_aligned(a, ...) \
__attribute__((__assume_aligned__(a, ## __VA_ARGS__)))