Raise the minimum required gcc version to 4.6

Various architectures fail to build properly with older versions of the
gcc compiler.

An example from Guenter Roeck in thread [1]:
>
>   In file included from ./include/linux/mm.h:17:0,
>                    from ./include/linux/pid_namespace.h:7,
>                    from ./include/linux/ptrace.h:10,
>                    from arch/openrisc/kernel/asm-offsets.c:32:
>   ./include/linux/mm_types.h:497:16: error: flexible array member in otherwise empty struct
>
> This is just an example with gcc 4.5.1 for or32. I have seen the problem
> with gcc 4.4 (for unicore32) as well.

So update the minimum required version of gcc to 4.6.

[1] https://lore.kernel.org/lkml/20180814170904.GA12768@roeck-us.net/

Miscellanea:

 - Update Documentation/process/changes.rst

 - Remove and consolidate version test blocks in compiler-gcc.h for
   versions lower than 4.6

Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Joe Perches 2018-08-20 13:15:26 -07:00 committed by Linus Torvalds
parent cc26ebbebd
commit cafa0010cd
2 changed files with 19 additions and 69 deletions

View file

@ -29,7 +29,7 @@ you probably needn't concern yourself with isdn4k-utils.
====================== =============== ========================================
Program Minimal version Command to check the version
====================== =============== ========================================
GNU C 3.2 gcc --version
GNU C 4.6 gcc --version
GNU make 3.81 make --version
binutils 2.20 ld -v
flex 2.5.35 flex --version

View file

@ -10,6 +10,10 @@
+ __GNUC_MINOR__ * 100 \
+ __GNUC_PATCHLEVEL__)
#if GCC_VERSION < 40600
# error Sorry, your compiler is too old - please upgrade it.
#endif
/* Optimization barrier */
/* The "volatile" is due to gcc bugs */
@ -58,6 +62,12 @@
#define OPTIMIZER_HIDE_VAR(var) \
__asm__ ("" : "=r" (var) : "0" (var))
/*
* A trick to suppress uninitialized variable warning without generating any
* code
*/
#define uninitialized_var(x) x = x
#ifdef __CHECKER__
#define __must_be_array(a) 0
#else
@ -91,7 +101,7 @@
* A lot of inline functions can cause havoc with function tracing.
*/
#if !defined(CONFIG_ARCH_SUPPORTS_OPTIMIZED_INLINING) || \
!defined(CONFIG_OPTIMIZE_INLINING) || (__GNUC__ < 4)
!defined(CONFIG_OPTIMIZE_INLINING)
#define inline \
inline __attribute__((always_inline, unused)) notrace __gnu_inline
#else
@ -147,47 +157,13 @@
#define __always_unused __attribute__((unused))
#define __mode(x) __attribute__((mode(x)))
/* gcc version specific checks */
#if GCC_VERSION < 30200
# error Sorry, your compiler is too old - please upgrade it.
#endif
#if GCC_VERSION < 30300
# define __used __attribute__((__unused__))
#else
# define __used __attribute__((__used__))
#endif
#ifdef CONFIG_GCOV_KERNEL
# if GCC_VERSION < 30400
# error "GCOV profiling support for gcc versions below 3.4 not included"
# endif /* __GNUC_MINOR__ */
#endif /* CONFIG_GCOV_KERNEL */
#if GCC_VERSION >= 30400
#define __must_check __attribute__((warn_unused_result))
#define __malloc __attribute__((__malloc__))
#endif
#if GCC_VERSION >= 40000
/* GCC 4.1.[01] miscompiles __weak */
#ifdef __KERNEL__
# if GCC_VERSION >= 40100 && GCC_VERSION <= 40101
# error Your version of gcc miscompiles the __weak directive
# endif
#endif
#define __used __attribute__((__used__))
#define __compiler_offsetof(a, b) \
__builtin_offsetof(a, b)
#if GCC_VERSION >= 40100
# define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
#endif
#if GCC_VERSION >= 40300
/* Mark functions as cold. gcc will assume any path leading to a call
* to them will be unlikely. This means a lot of manual unlikely()s
* are unnecessary now for any paths leading to the usual suspects
@ -206,24 +182,19 @@
#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
#ifndef __CHECKER__
# define __compiletime_warning(message) __attribute__((warning(message)))
# define __compiletime_error(message) __attribute__((error(message)))
#endif /* __CHECKER__ */
#endif /* GCC_VERSION >= 40300 */
#if GCC_VERSION >= 40400
#define __optimize(level) __attribute__((__optimize__(level)))
#define __nostackprotector __optimize("no-stack-protector")
#endif /* GCC_VERSION >= 40400 */
#if GCC_VERSION >= 40500
#define __compiletime_object_size(obj) __builtin_object_size(obj, 0)
#ifndef __CHECKER__
#define __compiletime_warning(message) __attribute__((warning(message)))
#define __compiletime_error(message) __attribute__((error(message)))
#ifdef LATENT_ENTROPY_PLUGIN
#define __latent_entropy __attribute__((latent_entropy))
#endif
#endif
#endif /* __CHECKER__ */
/*
* calling noreturn functions, __builtin_unreachable() and __builtin_trap()
@ -261,10 +232,6 @@
#define randomized_struct_fields_end } __randomize_layout;
#endif
#endif /* GCC_VERSION >= 40500 */
#if GCC_VERSION >= 40600
/*
* When used with Link Time Optimization, gcc can optimize away C functions or
* variables which are referenced only from assembly code. __visible tells the
@ -273,8 +240,7 @@
*/
#define __visible __attribute__((externally_visible))
#endif /* GCC_VERSION >= 40600 */
/* gcc version specific checks */
#if GCC_VERSION >= 40900 && !defined(__CHECKER__)
/*
@ -308,10 +274,8 @@
* folding in __builtin_bswap*() (yet), so don't set these for it.
*/
#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP) && !defined(__CHECKER__)
#if GCC_VERSION >= 40400
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#endif
#if GCC_VERSION >= 40800
#define __HAVE_BUILTIN_BSWAP16__
#endif
@ -340,10 +304,9 @@
* https://gcc.gnu.org/onlinedocs/gcc/Designated-Inits.html
*/
#define __designated_init __attribute__((designated_init))
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif
#endif /* gcc version >= 40000 specific checks */
#if !defined(__noclone)
#define __noclone /* not needed */
#endif
@ -352,16 +315,6 @@
#define __no_sanitize_address
#endif
/*
* A trick to suppress uninitialized variable warning without generating any
* code
*/
#define uninitialized_var(x) x = x
#if GCC_VERSION >= 50100
#define COMPILER_HAS_GENERIC_BUILTIN_OVERFLOW 1
#endif
/*
* Turn individual warnings and errors on and off locally, depending
* on version.
@ -374,12 +327,9 @@
#define __diag_GCC_warn warning
#define __diag_GCC_error error
/* Compilers before gcc-4.6 do not understand "#pragma GCC diagnostic push" */
#if GCC_VERSION >= 40600
#define __diag_str1(s) #s
#define __diag_str(s) __diag_str1(s)
#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
#endif
#if GCC_VERSION >= 80000
#define __diag_GCC_8(s) __diag(s)