linux-stable.git/include/linux/compiler_types.h, branch v5.1.2

include/linux/compiler_types.h: don't pollute userspace with macro definitions

2018-12-14T15:57:16+00:00

Macros 'inline' and '__gnu_inline' used to be defined in compiler-gcc.h,
which was (and is) included entirely in (__KERNEL__ && !__ASSEMBLY__).
Commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually
exclusive") had those macros exposed to userspace, unintentionally.

Then commit a3f8a30f3f00 ("Compiler Attributes: use feature checks
instead of version checks") moved '__gnu_inline' back into
(__KERNEL__ && !__ASSEMBLY__) and 'inline' was left behind. Since 'inline'
depends on '__gnu_inline', compiling error showing "unknown type name
‘__gnu_inline’" will pop up, if userspace somehow includes
.

Other macros like __must_check, notrace, etc. are in a similar situation.
So just move all these macros back into (__KERNEL__ && !__ASSEMBLY__).

Note:
  1. This patch only affects what userspace sees.
  2. __must_check (when !CONFIG_ENABLE_MUST_CHECK) and noinline_for_stack
     were once defined in __KERNEL__ only, but we believe that they can
     be put into !__ASSEMBLY__ too.

Acked-by: Nick Desaulniers 
Signed-off-by: Xiaozhou Liu 
Signed-off-by: Miguel Ojeda

include/linux/compiler*.h: define asm_volatile_goto

2018-11-06T14:30:16+00:00

asm_volatile_goto should also be defined for other compilers that support
asm goto.

Fixes commit 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h
mutually exclusive").

Signed-off-by: Nick Desaulniers 
Signed-off-by: Miguel Ojeda

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: add missing SPDX ID in compiler_types.h

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

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: remove unneeded tests

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

Attributes const and always_inline have tests around them
which are unneeded, since they are supported by gcc >= 4.6,
clang >= 3 and icc >= 13. https://godbolt.org/z/DFPq37

In the case of gnu_inline, we do not need to test for
__GNUC_STDC_INLINE__ because, regardless of the current
inlining behavior, we can simply always force the old
GCC inlining behavior by using the attribute in all cases.

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: always use the extra-underscores syntax

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

The attribute syntax optionally allows to surround attribute names
with "__" in order to avoid collisions with macros of the same name
(see https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html).

This homogenizes all attributes to use the syntax with underscores.
While there are currently only a handful of cases of some TUs defining
macros like "error" which may collide with the attributes,
this should prevent futures surprises.

This has been done only for "standard" attributes supported by
the major compilers. In other words, those of third-party tools
(e.g. sparse, plugins...) have not been changed for the moment.

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 unused attributes

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

__optimize and __deprecate_for_modules are unused in
the whole kernel tree. Simply drop them.

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: naked can be shared

2018-09-20T13:23:58+00:00

The naked attribute is supported by at least gcc >= 4.6 (for ARM,
which is the only current user), gcc >= 8 (for x86), clang >= 3.1
and icc >= 13. See https://godbolt.org/z/350Dyc

Therefore, move it out of compiler-gcc.h so that the definition
is shared by all compilers.

This also fixes Clang support for ARM32 --- 815f0ddb346c
("include/linux/compiler*.h: make compiler-*.h mutually exclusive").

Fixes: 815f0ddb346c ("include/linux/compiler*.h: make compiler-*.h mutually exclusive")
Cc: Rasmus Villemoes 
Cc: Eli Friedman 
Cc: Christopher Li 
Cc: Kees Cook 
Cc: Ingo Molnar 
Cc: Geert Uytterhoeven 
Cc: Greg Kroah-Hartman 
Cc: Masahiro Yamada 
Cc: Joe Perches 
Cc: Dominique Martinet 
Cc: Linus Torvalds 
Cc: linux-sparse@vger.kernel.org
Suggested-by: Arnd Bergmann 
Tested-by: Stefan Agner 
Reviewed-by: Stefan Agner 
Reviewed-by: Luc Van Oostenryck 
Reviewed-by: Nick Desaulniers 
Signed-off-by: Miguel Ojeda 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

2018-08-23T21:23:08+00:00

Pull MIPS fixes from Paul Burton:

  - Fix microMIPS build failures by adding a .insn directive to the
    barrier_before_unreachable() asm statement in order to convince the
    toolchain that the asm statement is a valid branch target rather
    than a bogus attempt to switch ISA.

  - Clean up our declarations of TLB functions that we overwrite with
    generated code in order to prevent the compiler making assumptions
    about alignment that cause microMIPS kernels built with GCC 7 &
    above to die early during boot.

  - Fix up a regression for MIPS32 kernels which slipped into the main
    MIPS pull for 4.19, causing CONFIG_32BIT=y kernels to contain
    inappropriate MIPS64 instructions.

  - Extend our existing workaround for MIPSr6 builds that end up using
    the __multi3 intrinsic to GCC 7 & below, rather than just GCC 7.

* tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: lib: Provide MIPS64r6 __multi3() for GCC < 7
  MIPS: Workaround GCC __builtin_unreachable reordering bug
  compiler.h: Allow arch-specific asm/compiler.h
  MIPS: Avoid move psuedo-instruction whilst using MIPS_ISA_LEVEL
  MIPS: Consistently declare TLB functions
  MIPS: Export tlbmiss_handler_setup_pgd near its definition

linux-stable.git/include/linux/compiler_types.h, branch v5.1.2

include/linux/compiler_types.h: don't pollute userspace with macro definitions

include/linux/compiler*.h: define asm_volatile_goto

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: remove unneeded tests

Compiler Attributes: always use the extra-underscores syntax

Compiler Attributes: remove unused attributes

Compiler Attributes: naked can be shared

Merge tag 'mips_4.19_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux

Compiler Attributes: remove unneeded sparse (CHECKER) tests