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192.168.1.100 / T108 / 47b34e91362a090f8a2559999ea97b0b41a9572f / . / target / linux / generic / hack-5.4 / 221-module_exports.patch
blob: e8b775e2a90e63f185d0b91742e6b5d776353d96 [file] [log] [blame]
b.liue9582032025-04-17 19:18:16 +0800[diff] [blame]1From b14784e7883390c20ed3ff904892255404a5914b Mon Sep 17 00:00:00 2001
2From: Felix Fietkau <nbd@nbd.name>
3Date: Fri, 7 Jul 2017 17:05:53 +0200
4Subject: add an optional config option for stripping all unnecessary symbol exports from the kernel image
5
6lede-commit: bb5a40c64b7c4f4848509fa0a6625055fc9e66cc
7Signed-off-by: Felix Fietkau <nbd@nbd.name>
8---
9 include/asm-generic/vmlinux.lds.h | 18 +++++++++++++++---
10 include/linux/export.h | 9 ++++++++-
11 scripts/Makefile.build | 2 +-
12 3 files changed, 24 insertions(+), 5 deletions(-)
13
14--- a/include/asm-generic/vmlinux.lds.h
15+++ b/include/asm-generic/vmlinux.lds.h
16@@ -54,6 +54,16 @@
17 #define LOAD_OFFSET 0
18 #endif
19
20+#ifndef SYMTAB_KEEP
21+#define SYMTAB_KEEP KEEP(*(SORT(___ksymtab+*)))
22+#define SYMTAB_KEEP_GPL KEEP(*(SORT(___ksymtab_gpl+*)))
23+#endif
24+
25+#ifndef SYMTAB_DISCARD
26+#define SYMTAB_DISCARD
27+#define SYMTAB_DISCARD_GPL
28+#endif
29+
30 /* Align . to a 8 byte boundary equals to maximum function alignment. */
31 #define ALIGN_FUNCTION() . = ALIGN(8)
32
33@@ -408,14 +418,14 @@
34 /* Kernel symbol table: Normal symbols */ \
35 __ksymtab : AT(ADDR(__ksymtab) - LOAD_OFFSET) { \
36 __start___ksymtab = .; \
37- KEEP(*(SORT(___ksymtab+*))) \
38+ SYMTAB_KEEP \
39 __stop___ksymtab = .; \
40 } \
41 \
42 /* Kernel symbol table: GPL-only symbols */ \
43 __ksymtab_gpl : AT(ADDR(__ksymtab_gpl) - LOAD_OFFSET) { \
44 __start___ksymtab_gpl = .; \
45- KEEP(*(SORT(___ksymtab_gpl+*))) \
46+ SYMTAB_KEEP_GPL \
47 __stop___ksymtab_gpl = .; \
48 } \
49 \
50@@ -477,7 +487,7 @@
51 \
52 /* Kernel symbol table: strings */ \
53 __ksymtab_strings : AT(ADDR(__ksymtab_strings) - LOAD_OFFSET) { \
54- *(__ksymtab_strings) \
55+ *(__ksymtab_strings+*) \
56 } \
57 \
58 /* __*init sections */ \
59@@ -917,6 +927,8 @@
60 /DISCARD/ : { \
61 EXIT_DISCARDS \
62 EXIT_CALL \
63+ SYMTAB_DISCARD \
64+ SYMTAB_DISCARD_GPL \
65 *(.discard) \
66 *(.discard.*) \
67 *(.modinfo) \
68--- a/include/linux/export.h
69+++ b/include/linux/export.h
70@@ -98,18 +98,26 @@ struct kernel_symbol {
71
72 #else
73
74+#ifdef MODULE
75+#define __EXPORT_SUFFIX(sym)
76+#else
77+#define __EXPORT_SUFFIX(sym) "+" #sym
78+#endif
79+
80 #define ___export_symbol_common(sym, sec) \
81 extern typeof(sym) sym; \
82 __CRC_SYMBOL(sym, sec); \
83 static const char __kstrtab_##sym[] \
84- __attribute__((section("__ksymtab_strings"), used, aligned(1))) \
85+ __attribute__((section("__ksymtab_strings" \
86+ __EXPORT_SUFFIX(sym)), used, aligned(1))) \
87 = #sym \
88
89 /* For every exported symbol, place a struct in the __ksymtab section */
90 #define ___EXPORT_SYMBOL_NS(sym, sec, ns) \
91 ___export_symbol_common(sym, sec); \
92 static const char __kstrtabns_##sym[] \
93- __attribute__((section("__ksymtab_strings"), used, aligned(1))) \
94+ __attribute__((section("__ksymtab_strings" \
95+ __EXPORT_SUFFIX(sym)), used, aligned(1))) \
96 = #ns; \
97 __KSYMTAB_ENTRY_NS(sym, sec)
98
99--- a/scripts/Makefile.build
100+++ b/scripts/Makefile.build
101@@ -350,7 +350,7 @@ targets += $(extra-y) $(MAKECMDGOALS) $(
102 # Linker scripts preprocessor (.lds.S -> .lds)
103 # ---------------------------------------------------------------------------
104 quiet_cmd_cpp_lds_S = LDS $@
105- cmd_cpp_lds_S = $(CPP) $(cpp_flags) -P -U$(ARCH) \
106+ cmd_cpp_lds_S = $(CPP) $(EXTRA_LDSFLAGS) $(cpp_flags) -P -U$(ARCH) \
107 -D__ASSEMBLY__ -DLINKER_SCRIPT -o $@ $<
108
109 $(obj)/%.lds: $(src)/%.lds.S FORCE