1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __LINUX_COMPILER_TYPES_H
3 #error "Please do not 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 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
56 #define __HAVE_BUILTIN_BSWAP32__
57 #define __HAVE_BUILTIN_BSWAP64__
58 #define __HAVE_BUILTIN_BSWAP16__
59 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
60 
61 #if GCC_VERSION >= 70000
62 #define KASAN_ABI_VERSION 5
63 #else
64 #define KASAN_ABI_VERSION 4
65 #endif
66 
67 #ifdef CONFIG_SHADOW_CALL_STACK
68 #define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
69 #endif
70 
71 #ifdef __SANITIZE_HWADDRESS__
72 #define __no_sanitize_address __attribute__((__no_sanitize__("hwaddress")))
73 #else
74 #define __no_sanitize_address __attribute__((__no_sanitize_address__))
75 #endif
76 
77 #if defined(__SANITIZE_THREAD__)
78 #define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
79 #else
80 #define __no_sanitize_thread
81 #endif
82 
83 #define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))
84 
85 /*
86  * Only supported since gcc >= 12
87  */
88 #if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
89 #define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
90 #else
91 #define __no_sanitize_coverage
92 #endif
93 
94 /*
95  * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
96  * matching the defines used by Clang.
97  */
98 #ifdef __SANITIZE_HWADDRESS__
99 #define __SANITIZE_ADDRESS__
100 #endif
101 
102 /*
103  * GCC does not support KMSAN.
104  */
105 #define __no_sanitize_memory
106 #define __no_kmsan_checks
107 
108 /*
109  * Turn individual warnings and errors on and off locally, depending
110  * on version.
111  */
112 #define __diag_GCC(version, severity, s) \
113 	__diag_GCC_ ## version(__diag_GCC_ ## severity s)
114 
115 /* Severity used in pragma directives */
116 #define __diag_GCC_ignore	ignored
117 #define __diag_GCC_warn		warning
118 #define __diag_GCC_error	error
119 
120 #define __diag_str1(s)		#s
121 #define __diag_str(s)		__diag_str1(s)
122 #define __diag(s)		_Pragma(__diag_str(GCC diagnostic s))
123 
124 #if GCC_VERSION >= 80000
125 #define __diag_GCC_8(s)		__diag(s)
126 #else
127 #define __diag_GCC_8(s)
128 #endif
129 
130 #define __diag_ignore_all(option, comment) \
131 	__diag(__diag_GCC_ignore option)
132 
133 /*
134  * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
135  * attribute) do not work, and must be disabled.
136  */
137 #if GCC_VERSION < 90100
138 #undef __alloc_size__
139 #endif
140