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) : ""(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 #if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
68 #define __HAVE_BUILTIN_BSWAP32__
69 #define __HAVE_BUILTIN_BSWAP64__
70 #define __HAVE_BUILTIN_BSWAP16__
71 #endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
72
73 #if GCC_VERSION >= 70000
74 #define KASAN_ABI_VERSION 5
75 #else
76 #define KASAN_ABI_VERSION 4
77 #endif
78
79 #ifdef CONFIG_SHADOW_CALL_STACK
80 #define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
81 #endif
82
83 #define __no_sanitize_address __attribute__((__no_sanitize_address__))
84
85 #if defined(__SANITIZE_THREAD__)
86 #define __no_sanitize_thread __attribute__((__no_sanitize_thread__))
87 #else
88 #define __no_sanitize_thread
89 #endif
90
91 #define __no_sanitize_undefined __attribute__((__no_sanitize_undefined__))
92
93 /*
94 * Only supported since gcc >= 12
95 */
96 #if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
97 #define __no_sanitize_coverage __attribute__((__no_sanitize_coverage__))
98 #else
99 #define __no_sanitize_coverage
100 #endif
101
102 /*
103 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
104 * matching the defines used by Clang.
105 */
106 #ifdef __SANITIZE_HWADDRESS__
107 #define __SANITIZE_ADDRESS__
108 #endif
109
110 /*
111 * GCC does not support KMSAN.
112 */
113 #define __no_sanitize_memory
114 #define __no_kmsan_checks
115
116 /*
117 * Turn individual warnings and errors on and off locally, depending
118 * on version.
119 */
120 #define __diag_GCC(version, severity, s) \
121 __diag_GCC_ ## version(__diag_GCC_ ## severity s)
122
123 /* Severity used in pragma directives */
124 #define __diag_GCC_ignore ignored
125 #define __diag_GCC_warn warning
126 #define __diag_GCC_error error
127
128 #define __diag_str1(s) #s
129 #define __diag_str(s) __diag_str1(s)
130 #define __diag(s) _Pragma(__diag_str(GCC diagnostic s))
131
132 #if GCC_VERSION >= 80000
133 #define __diag_GCC_8(s) __diag(s)
134 #else
135 #define __diag_GCC_8(s)
136 #endif
137
138 #define __diag_ignore_all(option, comment) \
139 __diag(__diag_GCC_ignore option)
140
141 /*
142 * Prior to 9.1, -Wno-alloc-size-larger-than (and therefore the "alloc_size"
143 * attribute) do not work, and must be disabled.
144 */
145 #if GCC_VERSION < 90100
146 #undef __alloc_size__
147 #endif
148
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