forked from mirrors/linux
		
	The attribute was added in GCC 12.1. This will simplify future cleanups, and is closer to what we do in `compiler_attributes.h`. Link: https://godbolt.org/z/MGbT76j6G Link: https://lkml.kernel.org/r/20221021115956.9947-5-ojeda@kernel.org Signed-off-by: Miguel Ojeda <ojeda@kernel.org> Acked-by: Marco Elver <elver@google.com> Reviewed-by: Nathan Chancellor <nathan@kernel.org> Cc: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Dan Li <ashimida@linux.alibaba.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com> Cc: Nick Desaulniers <ndesaulniers@google.com> Cc: Uros Bizjak <ubizjak@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
		
			
				
	
	
		
			149 lines
		
	
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			149 lines
		
	
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef __LINUX_COMPILER_TYPES_H
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#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
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#endif
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/*
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 * Common definitions for all gcc versions go here.
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 */
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#define GCC_VERSION (__GNUC__ * 10000		\
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		     + __GNUC_MINOR__ * 100	\
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		     + __GNUC_PATCHLEVEL__)
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/*
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 * This macro obfuscates arithmetic on a variable address so that gcc
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 * shouldn't recognize the original var, and make assumptions about it.
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 *
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 * This is needed because the C standard makes it undefined to do
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 * pointer arithmetic on "objects" outside their boundaries and the
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 * gcc optimizers assume this is the case. In particular they
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 * assume such arithmetic does not wrap.
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 *
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 * A miscompilation has been observed because of this on PPC.
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 * To work around it we hide the relationship of the pointer and the object
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 * using this macro.
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 *
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 * Versions of the ppc64 compiler before 4.1 had a bug where use of
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 * RELOC_HIDE could trash r30. The bug can be worked around by changing
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 * the inline assembly constraint from =g to =r, in this particular
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 * case either is valid.
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 */
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#define RELOC_HIDE(ptr, off)						\
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({									\
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	unsigned long __ptr;						\
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	__asm__ ("" : "=r"(__ptr) : "0"(ptr));				\
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	(typeof(ptr)) (__ptr + (off));					\
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})
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#ifdef CONFIG_RETPOLINE
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#define __noretpoline __attribute__((__indirect_branch__("keep")))
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#endif
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#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
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#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
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#define __latent_entropy __attribute__((latent_entropy))
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#endif
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/*
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 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
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 * confuse the stack allocation in gcc, leading to overly large stack
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 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
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 *
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 * Adding an empty inline assembly before it works around the problem
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 */
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#define barrier_before_unreachable() asm volatile("")
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/*
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 * Mark a position in code as unreachable.  This can be used to
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 * suppress control flow warnings after asm blocks that transfer
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 * control elsewhere.
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 */
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#define unreachable() \
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	do {					\
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		annotate_unreachable();		\
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		barrier_before_unreachable();	\
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		__builtin_unreachable();	\
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	} while (0)
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#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
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#define __HAVE_BUILTIN_BSWAP32__
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#define __HAVE_BUILTIN_BSWAP64__
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#define __HAVE_BUILTIN_BSWAP16__
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#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
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#if GCC_VERSION >= 70000
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#define KASAN_ABI_VERSION 5
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#else
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#define KASAN_ABI_VERSION 4
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#endif
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#ifdef CONFIG_SHADOW_CALL_STACK
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#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
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#endif
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#define __no_sanitize_address __attribute__((__no_sanitize_address__))
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#if defined(__SANITIZE_THREAD__)
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#define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
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#else
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#define __no_sanitize_thread
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#endif
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#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))
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/*
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 * Only supported since gcc >= 12
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 */
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#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
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#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
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#else
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#define __no_sanitize_coverage
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#endif
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/*
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 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
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 * matching the defines used by Clang.
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 */
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#ifdef __SANITIZE_HWADDRESS__
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#define __SANITIZE_ADDRESS__
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#endif
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/*
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 * GCC does not support KMSAN.
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 */
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#define __no_sanitize_memory
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#define __no_kmsan_checks
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/*
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 * Turn individual warnings and errors on and off locally, depending
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 * on version.
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 */
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#define __diag_GCC(version, severity, s) \
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	__diag_GCC_ ## version(__diag_GCC_ ## severity s)
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/* Severity used in pragma directives */
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#define __diag_GCC_ignore	ignored
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#define __diag_GCC_warn		warning
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#define __diag_GCC_error	error
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#define __diag_str1(s)		#s
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#define __diag_str(s)		__diag_str1(s)
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#define __diag(s)		_Pragma(__diag_str(GCC diagnostic s))
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#if GCC_VERSION >= 80000
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#define __diag_GCC_8(s)		__diag(s)
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#else
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#define __diag_GCC_8(s)
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#endif
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#define __diag_ignore_all(option, comment) \
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	__diag_GCC(8, ignore, option)
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/*
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 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
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 * attribute) do not work, and must be disabled.
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 */
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#if GCC_VERSION < 90100
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#undef __alloc_size__
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#endif
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