Linux kernel mirror (for testing)
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linux
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_RETPOLINE
39#define __noretpoline __attribute__((__indirect_branch__("keep")))
40#endif
41
42#define __UNIQUE_ID(prefix) __PASTE(__PASTE(__UNIQUE_ID_, prefix), __COUNTER__)
43
44#if defined(LATENT_ENTROPY_PLUGIN) && !defined(__CHECKER__)
45#define __latent_entropy __attribute__((latent_entropy))
46#endif
47
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
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.
61 */
62#define unreachable() \
63 do { \
64 annotate_unreachable(); \
65 barrier_before_unreachable(); \
66 __builtin_unreachable(); \
67 } while (0)
68
69#if defined(RANDSTRUCT_PLUGIN) && !defined(__CHECKER__)
70#define __randomize_layout __attribute__((randomize_layout))
71#define __no_randomize_layout __attribute__((no_randomize_layout))
72/* This anon struct can add padding, so only enable it under randstruct. */
73#define randomized_struct_fields_start struct {
74#define randomized_struct_fields_end } __randomize_layout;
75#endif
76
77/*
78 * GCC 'asm goto' miscompiles certain code sequences:
79 *
80 * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670
81 *
82 * Work it around via a compiler barrier quirk suggested by Jakub Jelinek.
83 *
84 * (asm goto is automatically volatile - the naming reflects this.)
85 */
86#define asm_volatile_goto(x...) do { asm goto(x); asm (""); } while (0)
87
88#if defined(CONFIG_ARCH_USE_BUILTIN_BSWAP)
89#define __HAVE_BUILTIN_BSWAP32__
90#define __HAVE_BUILTIN_BSWAP64__
91#define __HAVE_BUILTIN_BSWAP16__
92#endif /* CONFIG_ARCH_USE_BUILTIN_BSWAP */
93
94#if GCC_VERSION >= 70000
95#define KASAN_ABI_VERSION 5
96#else
97#define KASAN_ABI_VERSION 4
98#endif
99
100#ifdef CONFIG_SHADOW_CALL_STACK
101#define __noscs __attribute__((__no_sanitize__("shadow-call-stack")))
102#endif
103
104#if __has_attribute(__no_sanitize_address__)
105#define __no_sanitize_address __attribute__((no_sanitize_address))
106#else
107#define __no_sanitize_address
108#endif
109
110#if defined(__SANITIZE_THREAD__) && __has_attribute(__no_sanitize_thread__)
111#define __no_sanitize_thread __attribute__((no_sanitize_thread))
112#else
113#define __no_sanitize_thread
114#endif
115
116#if __has_attribute(__no_sanitize_undefined__)
117#define __no_sanitize_undefined __attribute__((no_sanitize_undefined))
118#else
119#define __no_sanitize_undefined
120#endif
121
122#if defined(CONFIG_KCOV) && __has_attribute(__no_sanitize_coverage__)
123#define __no_sanitize_coverage __attribute__((no_sanitize_coverage))
124#else
125#define __no_sanitize_coverage
126#endif
127
128/*
129 * Treat __SANITIZE_HWADDRESS__ the same as __SANITIZE_ADDRESS__ in the kernel,
130 * matching the defines used by Clang.
131 */
132#ifdef __SANITIZE_HWADDRESS__
133#define __SANITIZE_ADDRESS__
134#endif
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_GCC(8, 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