Commit 0b999ae3 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'compiler-attributes-for-linus-v5.0-rc7' of git://github.com/ojeda/linux 

Pull compiler attributes fixes from Miguel Ojeda:
 "Clean the new GCC 9 -Wmissing-attributes warnings

  The upcoming GCC 9 release extends the -Wmissing-attributes warnings
  (enabled by -Wall) to C and aliases: it warns when particular function
  attributes are missing in the aliases but not in their target, e.g.:

    void __cold f(void) {}
    void __alias("f") g(void);

  diagnoses:

    warning: 'g' specifies less restrictive attribute than
    its target 'f': 'cold' [-Wmissing-attributes]

  These patch series clean these new warnings. Most of them are caused
  by the module_init/exit macros"

Link: https://lore.kernel.org/lkml/20190125104353.2791-1-labbott@redhat.com/

* tag 'compiler-attributes-for-linus-v5.0-rc7' of git://github.com/ojeda/linux:
  include/linux/module.h: copy __init/__exit attrs to init/cleanup_module
  Compiler Attributes: add support for __copy (gcc >= 9)
  lib/crc32.c: mark crc32_le_base/__crc32c_le_base aliases as __pure
parents 5ded5871 a6e60d84

include/linux/compiler_attributes.h

+14 −0
Original line number Diff line number Diff line
@@ -34,6 +34,7 @@ 
#ifndef __has_attribute

# define __has_attribute(x) __GCC4_has_attribute_##x

# define __GCC4_has_attribute___assume_aligned__      (__GNUC_MINOR__ >= 9)

# define __GCC4_has_attribute___copy__                0

# define __GCC4_has_attribute___designated_init__     0

# define __GCC4_has_attribute___externally_visible__  1

# define __GCC4_has_attribute___noclone__             1
@@ -100,6 +101,19 @@ 
 */

#define __attribute_const__             __attribute__((__const__))



/*

 * Optional: only supported since gcc >= 9

 * Optional: not supported by clang

 * Optional: not supported by icc

 *

 *   gcc: https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-copy-function-attribute

 */

#if __has_attribute(__copy__)

# define __copy(symbol)                 __attribute__((__copy__(symbol)))

#else

# define __copy(symbol)

#endif



/*

 * Don't. Just don't. See commit 771c035372a0 ("deprecate the '__deprecated'

 * attribute warnings entirely and for good") for more information.

include/linux/module.h

+2 −2
Original line number Diff line number Diff line
@@ -129,13 +129,13 @@ extern void cleanup_module(void); 
#define module_init(initfn)					\

	static inline initcall_t __maybe_unused __inittest(void)		\

	{ return initfn; }					\

	int init_module(void) __attribute__((alias(#initfn)));

	int init_module(void) __copy(initfn) __attribute__((alias(#initfn)));



/* This is only required if you want to be unloadable. */

#define module_exit(exitfn)					\

	static inline exitcall_t __maybe_unused __exittest(void)		\

	{ return exitfn; }					\

	void cleanup_module(void) __attribute__((alias(#exitfn)));

	void cleanup_module(void) __copy(exitfn) __attribute__((alias(#exitfn)));



#endif

lib/crc32.c

+2 −2
Original line number Diff line number Diff line
@@ -206,8 +206,8 @@ u32 __pure __weak __crc32c_le(u32 crc, unsigned char const *p, size_t len) 
EXPORT_SYMBOL(crc32_le);

EXPORT_SYMBOL(__crc32c_le);



u32 crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le);

u32 __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le);

u32 __pure crc32_le_base(u32, unsigned char const *, size_t) __alias(crc32_le);

u32 __pure __crc32c_le_base(u32, unsigned char const *, size_t) __alias(__crc32c_le);



/*

 * This multiplies the polynomials x and y modulo the given modulus.

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