1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef __LINUX_COMPILER_TYPES_H
3#error "Please don't include <linux/compiler-gcc.h> directly, include <linux/compiler.h> instead."
4#endif
5
6/*
7 * Common definitions for all gcc versions go here.
8 */
9#define GCC_VERSION (__GNUC__ * 10000		\
10		     + __GNUC_MINOR__ * 100	\
11		     + __GNUC_PATCHLEVEL__)
12
13/*
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 *
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 */
31#define RELOC_HIDE(ptr, off)						\
32({									\
33	unsigned long __ptr;						\
34	__asm__ ("" : "=r"(__ptr) : "0"(ptr));				\
35	(typeof(ptr)) (__ptr + (off));					\
36})
37
38#ifdef CONFIG_MITIGATION_RETPOLINE
39#define __noretpoline __attribute__((__indirect_branch__("keep")))
40#endif
41
42#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
43#define __latent_entropy __attribute__((latent_entropy))
44#endif
45
46/*
47 * calling noreturn functions, __builtin_unreachable() and __builtin_trap()
48 * confuse the stack allocation in gcc, leading to overly large stack
49 * frames, see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82365
50 *
51 * Adding an empty inline assembly before it works around the problem
52 */
53#define barrier_before_unreachable() asm volatile("")
54
55/*
56 * Mark a position in code as unreachable.  This can be used to
57 * suppress control flow warnings after asm blocks that transfer
58 * control elsewhere.
59 */
60#define unreachable() \
61	do {					\
62		annotate_unreachable();		\
63		barrier_before_unreachable();	\
64		__builtin_unreachable();	\
65	} while (0)
66
67/*
68 * GCC 'asm goto' with outputs miscompiles certain code sequences:
69 *
70 *   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113921
71 *
72 * Work around it via the same compiler barrier quirk that we used
73 * to use for the old 'asm goto' workaround.
74 *
75 * Also, always mark such 'asm goto' statements as volatile: all
76 * asm goto statements are supposed to be volatile as per the
77 * documentation, but some versions of gcc didn't actually do
78 * that for asms with outputs:
79 *
80 *    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98619
81 */
82#ifdef CONFIG_GCC_ASM_GOTO_OUTPUT_WORKAROUND
83#define asm_goto_output(x...) \
84	do { asm volatile goto(x); asm (""); } while (0)
85#endif
86
87#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
88#define __HAVE_BUILTIN_BSWAP32__
89#define __HAVE_BUILTIN_BSWAP64__
90#define __HAVE_BUILTIN_BSWAP16__
91#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
92
93#if GCC_VERSION >= 70000
94#define KASAN_ABI_VERSION 5
95#else
96#define KASAN_ABI_VERSION 4
97#endif
98
99#ifdef CONFIG_SHADOW_CALL_STACK
100#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
101#endif
102
103#define __no_sanitize_address __attribute__((__no_sanitize_address__))
104
105#if defined(__SANITIZE_THREAD__)
106#define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
107#else
108#define __no_sanitize_thread
109#endif
110
111#define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))
112
113/*
114 * Only supported since gcc >= 12
115 */
116#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
117#define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
118#else
119#define __no_sanitize_coverage
120#endif
121
122/*
123 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
124 * matching the defines used by Clang.
125 */
126#ifdef __SANITIZE_HWADDRESS__
127#define __SANITIZE_ADDRESS__
128#endif
129
130/*
131 * GCC does not support KMSAN.
132 */
133#define __no_sanitize_memory
134#define __no_kmsan_checks
135
136/*
137 * Turn individual warnings and errors on and off locally, depending
138 * on version.
139 */
140#define __diag_GCC(version, severity, s) \
141	__diag_GCC_ ## version(__diag_GCC_ ## severity s)
142
143/* Severity used in pragma directives */
144#define __diag_GCC_ignore	ignored
145#define __diag_GCC_warn		warning
146#define __diag_GCC_error	error
147
148#define __diag_str1(s)		#s
149#define __diag_str(s)		__diag_str1(s)
150#define __diag(s)		_Pragma(__diag_str(GCC diagnostic s))
151
152#if GCC_VERSION >= 80000
153#define __diag_GCC_8(s)		__diag(s)
154#else
155#define __diag_GCC_8(s)
156#endif
157
158#define __diag_ignore_all(option, comment) \
159	__diag(__diag_GCC_ignore option)
160
161/*
162 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
163 * attribute) do not work, and must be disabled.
164 */
165#if GCC_VERSION < 90100
166#undef __alloc_size__
167#endif
168