Commit 71391bdd authored by Xiaozhou Liu's avatar Xiaozhou Liu Committed by Miguel Ojeda

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

Macros 'inline' and '__gnu_inline' used to be defined in compiler-gcc.h,
which was (and is) included entirely in (__KERNEL__ && !__ASSEMBLY__).
Commit 815f0ddb ("include/linux/compiler*.h: make compiler-*.h mutually
exclusive") had those macros exposed to userspace, unintentionally.

Then commit a3f8a30f ("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
<linux/compiler.h>.

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: default avatarNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: default avatarXiaozhou Liu <liuxiaozhou@bytedance.com>
Signed-off-by: default avatarMiguel Ojeda <miguel.ojeda.sandonis@gmail.com>
parent 40e020c1
......@@ -104,6 +104,60 @@ struct ftrace_likely_data {
unsigned long constant;
};
#ifdef CONFIG_ENABLE_MUST_CHECK
#define __must_check __attribute__((__warn_unused_result__))
#else
#define __must_check
#endif
#if defined(CC_USING_HOTPATCH)
#define notrace __attribute__((hotpatch(0, 0)))
#else
#define notrace __attribute__((__no_instrument_function__))
#endif
/*
* it doesn't make sense on ARM (currently the only user of __naked)
* to trace naked functions because then mcount is called without
* stack and frame pointer being set up and there is no chance to
* restore the lr register to the value before mcount was called.
*/
#define __naked __attribute__((__naked__)) notrace
#define __compiler_offsetof(a, b) __builtin_offsetof(a, b)
/*
* Force always-inline if the user requests it so via the .config.
* GCC does not warn about unused static inline functions for
* -Wunused-function. This turns out to avoid the need for complex #ifdef
* directives. Suppress the warning in clang as well by using "unused"
* function attribute, which is redundant but not harmful for gcc.
* Prefer gnu_inline, so that extern inline functions do not emit an
* externally visible function. This makes extern inline behave as per gnu89
* semantics rather than c99. This prevents multiple symbol definition errors
* of extern inline functions at link time.
* A lot of inline functions can cause havoc with function tracing.
* Do not use __always_inline here, since currently it expands to inline again
* (which would break users of __always_inline).
*/
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
!defined(CONFIG_OPTIMIZE_INLINING)
#define inline inline __attribute__((__always_inline__)) __gnu_inline \
__maybe_unused notrace
#else
#define inline inline __gnu_inline \
__maybe_unused notrace
#endif
#define __inline__ inline
#define __inline inline
/*
* Rather then using noinline to prevent stack consumption, use
* noinline_for_stack instead. For documentation reasons.
*/
#define noinline_for_stack noinline
#endif /* __KERNEL__ */
#endif /* __ASSEMBLY__ */
......@@ -161,58 +215,4 @@ struct ftrace_likely_data {
#define __diag_error(compiler, version, option, comment) \
__diag_ ## compiler(version, error, option)
#ifdef CONFIG_ENABLE_MUST_CHECK
#define __must_check __attribute__((__warn_unused_result__))
#else
#define __must_check
#endif
#if defined(CC_USING_HOTPATCH)
#define notrace __attribute__((hotpatch(0, 0)))
#else
#define notrace __attribute__((__no_instrument_function__))
#endif
/*
* it doesn't make sense on ARM (currently the only user of __naked)
* to trace naked functions because then mcount is called without
* stack and frame pointer being set up and there is no chance to
* restore the lr register to the value before mcount was called.
*/
#define __naked __attribute__((__naked__)) notrace
#define __compiler_offsetof(a, b) __builtin_offsetof(a, b)
/*
* Force always-inline if the user requests it so via the .config.
* GCC does not warn about unused static inline functions for
* -Wunused-function. This turns out to avoid the need for complex #ifdef
* directives. Suppress the warning in clang as well by using "unused"
* function attribute, which is redundant but not harmful for gcc.
* Prefer gnu_inline, so that extern inline functions do not emit an
* externally visible function. This makes extern inline behave as per gnu89
* semantics rather than c99. This prevents multiple symbol definition errors
* of extern inline functions at link time.
* A lot of inline functions can cause havoc with function tracing.
* Do not use __always_inline here, since currently it expands to inline again
* (which would break users of __always_inline).
*/
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
!defined(CONFIG_OPTIMIZE_INLINING)
#define inline inline __attribute__((__always_inline__)) __gnu_inline \
__maybe_unused notrace
#else
#define inline inline __gnu_inline \
__maybe_unused notrace
#endif
#define __inline__ inline
#define __inline inline
/*
* Rather then using noinline to prevent stack consumption, use
* noinline_for_stack instead. For documentation reasons.
*/
#define noinline_for_stack noinline
#endif /* __LINUX_COMPILER_TYPES_H */
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