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authorLinus Torvalds <torvalds@linux-foundation.org>2020-01-31 11:42:13 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-01-31 11:42:13 -0800
commitddaefe8947b48b638f726cf89730ecc1000ebcc3 (patch)
treebb05a5fce7b944a25f63432be3c33d52e3b3cd02 /include/linux/export.h
parentc5951e7c8ee5cb04b8b41c32bf567b90117a2124 (diff)
parent6080d608eeff7cb5090a2ddbaf723bfb0ff133fc (diff)
Merge tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux
Pull module updates from Jessica Yu: "Summary of modules changes for the 5.6 merge window: - Add "MS" (SHF_MERGE|SHF_STRINGS) section flags to __ksymtab_strings to indicate to the linker that it can perform string deduplication (i.e., duplicate strings are reduced to a single copy in the string table). This means any repeated namespace string would be merged to just one entry in __ksymtab_strings. - Various code cleanups and small fixes (fix small memleak in error path, improve moduleparam docs, silence rcu warnings, improve error logging)" * tag 'modules-for-v5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/jeyu/linux: module.h: Annotate mod_kallsyms with __rcu module: avoid setting info->name early in case we can fall back to info->mod->name modsign: print module name along with error message kernel/module: Fix memleak in module_add_modinfo_attrs() export.h: reduce __ksymtab_strings string duplication by using "MS" section flags moduleparam: fix kerneldoc modules: lockdep: Suppress suspicious RCU usage warning
Diffstat (limited to 'include/linux/export.h')
-rw-r--r--include/linux/export.h33
1 files changed, 23 insertions, 10 deletions
diff --git a/include/linux/export.h b/include/linux/export.h
index 627841448293..fceb5e855717 100644
--- a/include/linux/export.h
+++ b/include/linux/export.h
@@ -82,16 +82,29 @@ struct kernel_symbol {
#else
-/* For every exported symbol, place a struct in the __ksymtab section */
-#define ___EXPORT_SYMBOL(sym, sec, ns) \
- extern typeof(sym) sym; \
- __CRC_SYMBOL(sym, sec); \
- static const char __kstrtab_##sym[] \
- __attribute__((section("__ksymtab_strings"), used, aligned(1))) \
- = #sym; \
- static const char __kstrtabns_##sym[] \
- __attribute__((section("__ksymtab_strings"), used, aligned(1))) \
- = ns; \
+/*
+ * For every exported symbol, do the following:
+ *
+ * - If applicable, place a CRC entry in the __kcrctab section.
+ * - Put the name of the symbol and namespace (empty string "" for none) in
+ * __ksymtab_strings.
+ * - Place a struct kernel_symbol entry in the __ksymtab section.
+ *
+ * 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
+ * former apparently works on all arches according to the binutils source.
+ */
+#define ___EXPORT_SYMBOL(sym, sec, ns) \
+ extern typeof(sym) sym; \
+ extern const char __kstrtab_##sym[]; \
+ extern const char __kstrtabns_##sym[]; \
+ __CRC_SYMBOL(sym, sec); \
+ asm(" .section \"__ksymtab_strings\",\"aMS\",%progbits,1 \n" \
+ "__kstrtab_" #sym ": \n" \
+ " .asciz \"" #sym "\" \n" \
+ "__kstrtabns_" #sym ": \n" \
+ " .asciz \"" ns "\" \n" \
+ " .previous \n"); \
__KSYMTAB_ENTRY(sym, sec)
#endif