aboutsummaryrefslogtreecommitdiffstats
path: root/target/linux/generic/hack-5.15/221-module_exports.patch
blob: 204027d769d8a201fa06d4bf01a5fb1e8759a785 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
From b14784e7883390c20ed3ff904892255404a5914b Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Fri, 7 Jul 2017 17:05:53 +0200
Subject: add an optional config option for stripping all unnecessary symbol exports from the kernel image

lede-commit: bb5a40c64b7c4f4848509fa0a6625055fc9e66cc
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 include/asm-generic/vmlinux.lds.h | 18 +++++++++++++++---
 include/linux/export.h            |  9 ++++++++-
 scripts/Makefile.build            |  2 +-
 3 files changed, 24 insertions(+), 5 deletions(-)

--- a/include/asm-generic/vmlinux.lds.h
+++ b/include/asm-generic/vmlinux.lds.h
@@ -81,6 +81,16 @@
 #define RO_EXCEPTION_TABLE
 #endif
 
+#ifndef SYMTAB_KEEP
+#define SYMTAB_KEEP KEEP(*(SORT(___ksymtab+*)))
+#define SYMTAB_KEEP_GPL KEEP(*(SORT(___ksymtab_gpl+*)))
+#endif
+
+#ifndef SYMTAB_DISCARD
+#define SYMTAB_DISCARD
+#define SYMTAB_DISCARD_GPL
+#endif
+
 /* Align . to a 8 byte boundary equals to maximum function alignment. */
 #define ALIGN_FUNCTION()  . = ALIGN(8)
 
@@ -484,14 +494,14 @@
 	/* Kernel symbol table: Normal symbols */			\
 	__ksymtab         : AT(ADDR(__ksymtab) - LOAD_OFFSET) {		\
 		__start___ksymtab = .;					\
-		KEEP(*(SORT(___ksymtab+*)))				\
+		SYMTAB_KEEP						\
 		__stop___ksymtab = .;					\
 	}								\
 									\
 	/* Kernel symbol table: GPL-only symbols */			\
 	__ksymtab_gpl     : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) {	\
 		__start___ksymtab_gpl = .;				\
-		KEEP(*(SORT(___ksymtab_gpl+*)))				\
+		SYMTAB_KEEP_GPL						\
 		__stop___ksymtab_gpl = .;				\
 	}								\
 									\
@@ -511,7 +521,7 @@
 									\
 	/* Kernel symbol table: strings */				\
         __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) {	\
-		*(__ksymtab_strings)					\
+		*(__ksymtab_strings+*)					\
 	}								\
 									\
 	/* __*init sections */						\
@@ -1018,6 +1028,8 @@
 
 #define COMMON_DISCARDS							\
 	SANITIZER_DISCARDS						\
+	SYMTAB_DISCARD							\
+	SYMTAB_DISCARD_GPL						\
 	*(.discard)							\
 	*(.discard.*)							\
 	*(.modinfo)							\
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -84,6 +84,12 @@ struct kernel_symbol {
 
 #else
 
+#ifdef MODULE
+#define __EXPORT_SUFFIX(sym)
+#else
+#define __EXPORT_SUFFIX(sym) "+" #sym
+#endif
+
 /*
  * For every exported symbol, do the following:
  *
@@ -101,7 +107,7 @@ struct kernel_symbol {
 	extern const char __kstrtab_##sym[];					\
 	extern const char __kstrtabns_##sym[];					\
 	__CRC_SYMBOL(sym, sec);							\
-	asm("	.section \"__ksymtab_strings\",\"aMS\",%progbits,1	\n"	\
+	asm("	.section \"__ksymtab_strings" __EXPORT_SUFFIX(sym) "\",\"aMS\",%progbits,1	\n"	\
 	    "__kstrtab_" #sym ":					\n"	\
 	    "	.asciz 	\"" #sym "\"					\n"	\
 	    "__kstrtabns_" #sym ":					\n"	\
--- a/include/asm-generic/export.h
+++ b/include/asm-generic/export.h
@@ -26,6 +26,12 @@
 #endif
 .endm
 
+#ifdef MODULE
+#define __EXPORT_SUFFIX(name)
+#else
+#define __EXPORT_SUFFIX(name) + #name
+#endif
+
 /*
  * note on .section use: we specify progbits since usage of the "M" (SHF_MERGE)
  * section flag requires it. Use '%progbits' instead of '@progbits' since the
@@ -39,7 +45,7 @@
 __ksymtab_\name:
 	__put \val, __kstrtab_\name
 	.previous
-	.section __ksymtab_strings,"aMS",%progbits,1
+	.section __ksymtab_strings __EXPORT_SUFFIX(name),"aMS",%progbits,1
 __kstrtab_\name:
 	.asciz "\name"
 	.previous
--- a/scripts/Makefile.build
+++ b/scripts/Makefile.build
@@ -397,7 +397,7 @@ targets += $(real-dtb-y) $(lib-y) $(alwa
 # Linker scripts preprocessor (.lds.S -> .lds)
 # ---------------------------------------------------------------------------
 quiet_cmd_cpp_lds_S = LDS     $@
-      cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
+      cmd_cpp_lds_S = $(CPP) $(EXTRA_LDSFLAGS) $(cpp_flags) -P -U$(ARCH) \
 	                     -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
 
 $(obj)/%.lds: $(src)/%.lds.S FORCE