[linux-block.git] / include / linux / compiler-gcc.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __LINUX_COMPILER_TYPES_H
#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
#endif

/*
 * Common definitions for all gcc versions go here.
 */
#define GCC_VERSION (__GNUC__ * 10000		\
		     + __GNUC_MINOR__ * 100	\
		     + __GNUC_PATCHLEVEL__)

/*
 * This macro obfuscates arithmetic on a variable address so that gcc
 * shouldn't recognize the original var, and make assumptions about it.
 *
 * This is needed because the C standard makes it undefined to do
 * pointer arithmetic on "objects" outside their boundaries and the
 * gcc optimizers assume this is the case. In particular they
 * assume such arithmetic does not wrap.
 *
 * A miscompilation has been observed because of this on PPC.
 * To work around it we hide the relationship of the pointer and the object
 * using this macro.
 *
 * Versions of the ppc64 compiler before 4.1 had a bug where use of
 * RELOC_HIDE could trash r30. The bug can be worked around by changing
 * the inline assembly constraint from =g to =r, in this particular
 * case either is valid.
 */
#define RELOC_HIDE(ptr, off)						\
({									\
	unsigned long __ptr;						\
	__asm__ ("" : "=r"(__ptr) : "0"(ptr));				\
	(typeof(ptr)) (__ptr + (off));					\
})

#ifdef CONFIG_RETPOLINE
#define __noretpoline __attribute__((__indirect_branch__("keep")))
#endif

#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)

#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
#define __latent_entropy __attribute__((latent_entropy))
#endif

/*
 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
 * confuse the stack allocation in gcc, leading to overly large stack
 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
 *
 * Adding an empty inline assembly before it works around the problem
 */
#define barrier_before_unreachable() asm volatile("")

/*
 * Mark a position in code as unreachable.  This can be used to
 * suppress control flow warnings after asm blocks that transfer
 * control elsewhere.
 */
#define unreachable() \
	do {					\
		annotate_unreachable();		\
		barrier_before_unreachable();	\
		__builtin_unreachable();	\
	} while (0)

#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
#define __HAVE_BUILTIN_BSWAP32__
#define __HAVE_BUILTIN_BSWAP64__
#define __HAVE_BUILTIN_BSWAP16__
#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */

#if GCC_VERSION >= 70000
#define KASAN_ABI_VERSION 5
#else
#define KASAN_ABI_VERSION 4
#endif

#ifdef CONFIG_SHADOW_CALL_STACK
#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
#endif

#define __no_sanitize_address __attribute__((__no_sanitize_address__))

#if defined(__SANITIZE_THREAD__)
#define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
#else
#define __no_sanitize_thread
#endif

#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))

/*
 * Only supported since gcc >= 12
 */
#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
#else
#define __no_sanitize_coverage
#endif

/*
 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
 * matching the defines used by Clang.
 */
#ifdef __SANITIZE_HWADDRESS__
#define __SANITIZE_ADDRESS__
#endif

/*
 * GCC does not support KMSAN.
 */
#define __no_sanitize_memory
#define __no_kmsan_checks

/*
 * Turn individual warnings and errors on and off locally, depending
 * on version.
 */
#define __diag_GCC(version, severity, s) \
	__diag_GCC_ ## version(__diag_GCC_ ## severity s)

/* Severity used in pragma directives */
#define __diag_GCC_ignore	ignored
#define __diag_GCC_warn		warning
#define __diag_GCC_error	error

#define __diag_str1(s)		#s
#define __diag_str(s)		__diag_str1(s)
#define __diag(s)		_Pragma(__diag_str(GCC diagnostic s))

#if GCC_VERSION >= 80000
#define __diag_GCC_8(s)		__diag(s)
#else
#define __diag_GCC_8(s)
#endif

#define __diag_ignore_all(option, comment) \
	__diag_GCC(8, ignore, option)

/*
 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
 * attribute) do not work, and must be disabled.
 */
#if GCC_VERSION < 90100
#undef __alloc_size__
#endif
Commit	Line	Data
b2441318	1	/* SPDX-License-Identifier: GPL-2.0 */
d1515582	2	#ifndef __LINUX_COMPILER_TYPES_H
94f582f8 RD	3	#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
94f582f8 RD	4	#endif
1da177e4 LT	5
	6	/*
	7	* Common definitions for all gcc versions go here.
	8	*/
f6d133f8 JP	9	#define GCC_VERSION (__GNUC__ * 10000 \
	10	+ __GNUC_MINOR__ * 100 \
	11	+ __GNUC_PATCHLEVEL__)
1da177e4	12
c8d52465	13	/*
85c210ed AK	14	* This macro obfuscates arithmetic on a variable address so that gcc
	15	* shouldn't recognize the original var, and make assumptions about it.
	16	*
	17	* This is needed because the C standard makes it undefined to do
	18	* pointer arithmetic on "objects" outside their boundaries and the
	19	* gcc optimizers assume this is the case. In particular they
	20	* assume such arithmetic does not wrap.
	21	*
	22	* A miscompilation has been observed because of this on PPC.
	23	* To work around it we hide the relationship of the pointer and the object
	24	* using this macro.
	25	*
c8d52465 AB	26	* Versions of the ppc64 compiler before 4.1 had a bug where use of
	27	* RELOC_HIDE could trash r30. The bug can be worked around by changing
	28	* the inline assembly constraint from =g to =r, in this particular
	29	* case either is valid.
	30	*/
f6d133f8 JP	31	#define RELOC_HIDE(ptr, off) \
	32	({ \
	33	unsigned long __ptr; \
	34	__asm__ ("" : "=r"(__ptr) : "0"(ptr)); \
	35	(typeof(ptr)) (__ptr + (off)); \
	36	})
a1365647	37
e4f35891	38	#ifdef CONFIG_RETPOLINE
5c67a52f	39	#define __noretpoline __attribute__((__indirect_branch__("keep")))
87358710 DW	40	#endif
87358710 DW	41
cb984d10 JP	42	#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
cb984d10 JP	43
989bd500	44	#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
0766f788 ER	45	#define __latent_entropy __attribute__((latent_entropy))
0766f788 ER	46	#endif
0766f788	47
173a3efd AB	48	/*
	49	* calling noreturn functions, __builtin_unreachable() and __builtin_trap()
	50	* confuse the stack allocation in gcc, leading to overly large stack
	51	* frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
	52	*
	53	* Adding an empty inline assembly before it works around the problem
	54	*/
	55	#define barrier_before_unreachable() asm volatile("")
	56
cb984d10 JP	57	/*
	58	* Mark a position in code as unreachable. This can be used to
	59	* suppress control flow warnings after asm blocks that transfer
	60	* control elsewhere.
cb984d10	61	*/
4e4636cf	62	#define unreachable() \
173a3efd AB	63	do { \
	64	annotate_unreachable(); \
	65	barrier_before_unreachable(); \
	66	__builtin_unreachable(); \
	67	} while (0)
cb984d10	68
d991bb1c	69	#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
cb984d10 JP	70	#define __HAVE_BUILTIN_BSWAP32__
cb984d10 JP	71	#define __HAVE_BUILTIN_BSWAP64__
cb984d10	72	#define __HAVE_BUILTIN_BSWAP16__
d991bb1c	73	#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
cb984d10	74
045d599a DV	75	#if GCC_VERSION >= 70000
045d599a DV	76	#define KASAN_ABI_VERSION 5
4e59869a	77	#else
cb984d10	78	#define KASAN_ABI_VERSION 4
cb984d10 JP	79	#endif
cb984d10 JP	80
afcf5441 DL	81	#ifdef CONFIG_SHADOW_CALL_STACK
	82	#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
	83	#endif
	84
6e2be1f2	85	#define __no_sanitize_address __attribute__((__no_sanitize_address__))
2bd926b4	86
095ac076	87	#if defined(__SANITIZE_THREAD__)
6e2be1f2	88	#define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
dfd402a4 ME	89	#else
	90	#define __no_sanitize_thread
	91	#endif
	92
6e2be1f2	93	#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))
5144f8a8	94
f39556bc MO	95	/*
	96	* Only supported since gcc >= 12
	97	*/
540540d0	98	#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
6e2be1f2	99	#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
540540d0 ME	100	#else
	101	#define __no_sanitize_coverage
	102	#endif
	103
9a48e756 KC	104	/*
	105	* Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
	106	* matching the defines used by Clang.
	107	*/
	108	#ifdef __SANITIZE_HWADDRESS__
	109	#define __SANITIZE_ADDRESS__
	110	#endif
	111
9b448bc2 AP	112	/*
	113	* GCC does not support KMSAN.
	114	*/
	115	#define __no_sanitize_memory
	116	#define __no_kmsan_checks
	117
8793bb7f AB	118	/*
	119	* Turn individual warnings and errors on and off locally, depending
	120	* on version.
	121	*/
	122	#define __diag_GCC(version, severity, s) \
	123	__diag_GCC_ ## version(__diag_GCC_ ## severity s)
	124
	125	/* Severity used in pragma directives */
	126	#define __diag_GCC_ignore ignored
	127	#define __diag_GCC_warn warning
	128	#define __diag_GCC_error error
	129
8793bb7f AB	130	#define __diag_str1(s) #s
	131	#define __diag_str(s) __diag_str1(s)
	132	#define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
8793bb7f AB	133
	134	#if GCC_VERSION >= 80000
	135	#define __diag_GCC_8(s) __diag(s)
	136	#else
	137	#define __diag_GCC_8(s)
	138	#endif
86cffecd	139
4d1ea705 KKD	140	#define __diag_ignore_all(option, comment) \
	141	__diag_GCC(8, ignore, option)
	142
86cffecd KC	143	/*
	144	* Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
	145	* attribute) do not work, and must be disabled.
	146	*/
	147	#if GCC_VERSION < 90100
	148	#undef __alloc_size__
	149	#endif