kernel/linux.git/include/linux/compiler-gcc.h, branch linux-4.20.y

include/linux/compiler*.h: fix OPTIMIZER_HIDE_VAR

2019-02-27T09:09:46+00:00

[ Upstream commit 3e2ffd655cc6a694608d997738989ff5572a8266 ] Since commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") clang no longer reuses the OPTIMIZER_HIDE_VAR macro from compiler-gcc - instead it gets the version in include/linux/compiler.h. Unfortunately that version doesn't actually prevent compiler from optimizing out the variable. Fix up by moving the macro out from compiler-gcc.h to compiler.h. Compilers without incline asm support will keep working since it's protected by an ifdef. Also fix up comments to match reality since we are no longer overriding any macros. Build-tested with gcc and clang. Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive") Cc: Eli Friedman Cc: Joe Perches Cc: Linus Torvalds Reviewed-by: Nick Desaulniers Signed-off-by: Michael S. Tsirkin Signed-off-by: Miguel Ojeda Signed-off-by: Sasha Levin

x86, modpost: Replace last remnants of RETPOLINE with CONFIG_RETPOLINE

2019-01-16T21:03:21+00:00

commit e4f358916d528d479c3c12bd2fd03f2d5a576380 upstream. Commit 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") replaced the RETPOLINE define with CONFIG_RETPOLINE checks. Remove the remaining pieces. [ bp: Massage commit message. ] Fixes: 4cd24de3a098 ("x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support") Signed-off-by: WANG Chao Signed-off-by: Borislav Petkov Reviewed-by: Zhenzhong Duan Reviewed-by: Masahiro Yamada Cc: "H. Peter Anvin" Cc: Andi Kleen Cc: Andrew Morton Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Daniel Borkmann Cc: David Woodhouse Cc: Geert Uytterhoeven Cc: Jessica Yu Cc: Jiri Kosina Cc: Kees Cook Cc: Konrad Rzeszutek Wilk Cc: Luc Van Oostenryck Cc: Michal Marek Cc: Miguel Ojeda Cc: Peter Zijlstra Cc: Tim Chen Cc: Vasily Gorbik Cc: linux-kbuild@vger.kernel.org Cc: srinivas.eeda@oracle.com Cc: stable Cc: x86-ml Link: https://lkml.kernel.org/r/20181210163725.95977-1-chao.wang@ucloud.cn Signed-off-by: Greg Kroah-Hartman

compiler: remove __no_sanitize_address_or_inline again

2018-11-05T16:14:18+00:00

The __no_sanitize_address_or_inline and __no_kasan_or_inline defines are almost identical. The only difference is that __no_kasan_or_inline does not have the 'notrace' attribute. To be able to replace __no_sanitize_address_or_inline with the older definition, add 'notrace' to __no_kasan_or_inline and change to two users of __no_sanitize_address_or_inline in the s390 code. The 'notrace' option is necessary for e.g. the __load_psw_mask function in arch/s390/include/asm/processor.h. Without the option it is possible to trace __load_psw_mask which leads to kernel stack overflow. Signed-off-by: Martin Schwidefsky Pointed-out-by: Andrey Ryabinin Acked-by: Steven Rostedt (VMware) Signed-off-by: Linus Torvalds

Merge tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux

2018-11-02T01:34:46+00:00

Pull compiler attribute updates from Miguel Ojeda: "This is an effort to disentangle the include/linux/compiler*.h headers and bring them up to date. The main idea behind the series is to use feature checking macros (i.e. __has_attribute) instead of compiler version checks (e.g. GCC_VERSION), which are compiler-agnostic (so they can be shared, reducing the size of compiler-specific headers) and version-agnostic. Other related improvements have been performed in the headers as well, which on top of the use of __has_attribute it has amounted to a significant simplification of these headers (e.g. GCC_VERSION is now only guarding a few non-attribute macros). This series should also help the efforts to support compiling the kernel with clang and icc. A fair amount of documentation and comments have also been added, clarified or removed; and the headers are now more readable, which should help kernel developers in general. The series was triggered due to the move to gcc >= 4.6. In turn, this series has also triggered Sparse to gain the ability to recognize __has_attribute on its own. Finally, the __nonstring variable attribute series has been also applied on top; plus two related patches from Nick Desaulniers for unreachable() that came a bit afterwards" * tag 'compiler-attributes-for-linus-4.20-rc1' of https://github.com/ojeda/linux: compiler-gcc: remove comment about gcc 4.5 from unreachable() compiler.h: update definition of unreachable() Compiler Attributes: ext4: remove local __nonstring definition Compiler Attributes: auxdisplay: panel: use __nonstring Compiler Attributes: enable -Wstringop-truncation on W=1 (gcc >= 8) Compiler Attributes: add support for __nonstring (gcc >= 8) Compiler Attributes: add MAINTAINERS entry Compiler Attributes: add Doc/process/programming-language.rst Compiler Attributes: remove uses of __attribute__ from compiler.h Compiler Attributes: KENTRY used twice the "used" attribute Compiler Attributes: use feature checks instead of version checks Compiler Attributes: add missing SPDX ID in compiler_types.h Compiler Attributes: remove unneeded sparse (__CHECKER__) tests Compiler Attributes: homogenize __must_be_array Compiler Attributes: remove unneeded tests Compiler Attributes: always use the extra-underscores syntax Compiler Attributes: remove unused attributes

Merge tag 's390-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

2018-10-23T10:14:47+00:00

Pull s390 updates from Martin Schwidefsky: - Improved access control for the zcrypt driver, multiple device nodes can now be created with different access control lists - Extend the pkey API to provide random protected keys, this is useful for encrypted swap device with ephemeral protected keys - Add support for virtually mapped kernel stacks - Rework the early boot code, this moves the memory detection into the boot code that runs prior to decompression. - Add KASAN support - Bug fixes and cleanups * tag 's390-4.20-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (83 commits) s390/pkey: move pckmo subfunction available checks away from module init s390/kasan: support preemptible kernel build s390/pkey: Load pkey kernel module automatically s390/perf: Return error when debug_register fails s390/sthyi: Fix machine name validity indication s390/zcrypt: fix broken zcrypt_send_cprb in-kernel api function s390/vmalloc: fix VMALLOC_START calculation s390/mem_detect: add missing include s390/dumpstack: print psw mask and address again s390/crypto: Enhance paes cipher to accept variable length key material s390/pkey: Introduce new API for transforming key blobs s390/pkey: Introduce new API for random protected key verification s390/pkey: Add sysfs attributes to emit secure key blobs s390/pkey: Add sysfs attributes to emit protected key blobs s390/pkey: Define protected key blob format s390/pkey: Introduce new API for random protected key generation s390/zcrypt: add ap_adapter_mask sysfs attribute s390/zcrypt: provide apfs failure code on type 86 error reply s390/zcrypt: zcrypt device driver cleanup s390/kasan: add support for mem= kernel parameter ...

compiler-gcc: remove comment about gcc 4.5 from unreachable()

2018-10-19T06:47:30+00:00

Remove the comment about being unable to detect __builtin_unreachable. __builtin_unreachable was implemented in the GCC 4.5 timeframe. The kernel's minimum supported version of GCC is 4.6 since commit cafa0010cd51 ("Raise the minimum required gcc version to 4.6"). Commit cb984d101b30 ("compiler-gcc: integrate the various compiler-gcc[345].h files") shows that unreachable() had different guards based on GCC version. Suggested-by: Miguel Ojeda Signed-off-by: Nick Desaulniers Signed-off-by: Miguel Ojeda

compiler: introduce __no_sanitize_address_or_inline

2018-10-09T09:21:25+00:00

Due to conflict between kasan instrumentation and inlining https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67368 functions which are defined as inline could not be called from functions defined with __no_sanitize_address. Introduce __no_sanitize_address_or_inline which would expand to __no_sanitize_address when the kernel is built with kasan support and to inline otherwise. This helps to avoid disabling kasan instrumentation for entire files. Reviewed-by: Martin Schwidefsky Signed-off-by: Vasily Gorbik Signed-off-by: Martin Schwidefsky

Compiler Attributes: use feature checks instead of version checks

2018-09-30T18:14:03+00:00

Instead of using version checks per-compiler to define (or not) each attribute, use __has_attribute to test for them, following the cleanup started with commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive"), which is supported on gcc >= 5, clang >= 2.9 and icc >= 17. In the meantime, to support 4.6 <= gcc < 5, we implement __has_attribute by hand. All the attributes that can be unconditionally defined and directly map to compiler attribute(s) (even if optional) have been moved to a new file include/linux/compiler_attributes.h In an effort to make the file as regular as possible, comments stating the purpose of attributes have been removed. Instead, links to the compiler docs have been added (i.e. to gcc and, if available, to clang as well). In addition, they have been sorted. Finally, if an attribute is optional (i.e. if it is guarded by __has_attribute), the reason has been stated for future reference. Tested-by: Sedat Dilek # on top of v4.19-rc5, clang 7 Reviewed-by: Nick Desaulniers Reviewed-by: Luc Van Oostenryck Signed-off-by: Miguel Ojeda

Compiler Attributes: remove unneeded sparse (CHECKER) tests

2018-09-30T18:14:03+00:00

Sparse knows about a few more attributes now, so we can remove the __CHECKER__ conditions from them (which, in turn, allow us to move some of them later on to compiler_attributes.h). * assume_aligned: since sparse's commit ffc860b ("sparse: ignore __assume_aligned__ attribute"), included in 0.5.1 * error: since sparse's commit 0a04210 ("sparse: Add 'error' to ignored attributes"), included in 0.5.0 * hotpatch: since sparse's commit 6043210 ("sparse/parse.c: ignore hotpatch attribute"), included in 0.5.1 * warning: since sparse's commit 977365d ("Avoid "attribute 'warning': unknown attribute" warning"), included in 0.4.2 On top of that, __must_be_array does not need it either because: * Even ancient versions of sparse do not have a problem * BUILD_BUG_ON_ZERO() is currently disabled for __CHECKER__ Tested-by: Sedat Dilek # on top of v4.19-rc5, clang 7 Reviewed-by: Nick Desaulniers Reviewed-by: Luc Van Oostenryck Signed-off-by: Miguel Ojeda

Compiler Attributes: homogenize __must_be_array

2018-09-30T18:14:03+00:00

Different definitions of __must_be_array: * gcc: disabled for __CHECKER__ * clang: same definition as gcc's, but without __CHECKER__ * intel: the comment claims __builtin_types_compatible_p() is unsupported; but icc seems to support it since 13.0.1 (released in 2012). See https://godbolt.org/z/S0l6QQ Therefore, we can remove all of them and have a single definition in compiler.h Tested-by: Sedat Dilek # on top of v4.19-rc5, clang 7 Reviewed-by: Nick Desaulniers Reviewed-by: Luc Van Oostenryck Signed-off-by: Miguel Ojeda