xref: /linux/include/linux/export-internal.h (revision 55fcb926b6d8b5cfb40873e4840a69961db1bb69)
1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3  * Please do not include this explicitly.
4  * This is used by C files generated by modpost.
5  */
6 
7 #ifndef __LINUX_EXPORT_INTERNAL_H__
8 #define __LINUX_EXPORT_INTERNAL_H__
9 
10 #include <linux/compiler.h>
11 #include <linux/types.h>
12 
13 #if defined(CONFIG_HAVE_ARCH_PREL32_RELOCATIONS)
14 /*
15  * relative reference: this reduces the size by half on 64-bit architectures,
16  * and eliminates the need for absolute relocations that require runtime
17  * processing on relocatable kernels.
18  */
19 #define __KSYM_ALIGN		".balign 4"
20 #define __KSYM_REF(sym)		".long " #sym "- ."
21 #elif defined(CONFIG_64BIT)
22 #define __KSYM_ALIGN		".balign 8"
23 #define __KSYM_REF(sym)		".quad " #sym
24 #else
25 #define __KSYM_ALIGN		".balign 4"
26 #define __KSYM_REF(sym)		".long " #sym
27 #endif
28 
29 /*
30  * For every exported symbol, do the following:
31  *
32  * - Put the name of the symbol and namespace (empty string "" for none) in
33  *   __ksymtab_strings.
34  * - Place a struct kernel_symbol entry in the __ksymtab section.
35  *
36  * Note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
37  * section flag requires it. Use '%progbits' instead of '@progbits' since the
38  * former apparently works on all arches according to the binutils source.
39  */
40 #define __KSYMTAB(name, sym, ns)						\
41 	asm("	.section \"__ksymtab_strings\",\"aMS\",%progbits,1"	"\n"	\
42 	    "__kstrtab_" #name ":"					"\n"	\
43 	    "	.asciz \"" #name "\""					"\n"	\
44 	    "__kstrtabns_" #name ":"					"\n"	\
45 	    "	.asciz \"" ns "\""					"\n"	\
46 	    "	.previous"						"\n"	\
47 	    "	.section \"___ksymtab+" #name "\", \"a\""		"\n"	\
48 		__KSYM_ALIGN						"\n"	\
49 	    "__ksymtab_" #name ":"					"\n"	\
50 		__KSYM_REF(sym)						"\n"	\
51 		__KSYM_REF(__kstrtab_ ##name)				"\n"	\
52 		__KSYM_REF(__kstrtabns_ ##name)				"\n"	\
53 	    "	.previous"						"\n"	\
54 	)
55 
56 #if defined(CONFIG_PARISC) && defined(CONFIG_64BIT)
57 #define KSYM_FUNC(name)		P%name
58 #else
59 #define KSYM_FUNC(name)		name
60 #endif
61 
62 #define KSYMTAB_FUNC(name, ns)	__KSYMTAB(name, KSYM_FUNC(name), ns)
63 #define KSYMTAB_DATA(name, ns)	__KSYMTAB(name, name, ns)
64 
65 #define SYMBOL_CRC(sym, crc)					\
66 	asm("	.section \"___kcrctab+" #sym "\",\"a\""	"\n"	\
67 	    "	.balign 4"				"\n"	\
68 	    "__crc_" #sym ":"				"\n"	\
69 	    "	.long " #crc				"\n"	\
70 	    "	.previous"				"\n"	\
71 	)
72 
73 #define SYMBOL_FLAGS(sym, flags)					\
74 	asm("	.section \"___kflagstab+" #sym "\",\"a\""	"\n"	\
75 	    "__flags_" #sym ":"					"\n"	\
76 	    "	.byte " #flags					"\n"	\
77 	    "	.previous"					"\n"	\
78 	)
79 
80 #endif /* __LINUX_EXPORT_INTERNAL_H__ */
81