From 07cc2c931e8e1083a31f4c51d2244fe264af63bf Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Mon, 16 Jan 2023 11:10:07 +0100 Subject: livepatch: Improve the search performance of module_kallsyms_on_each_symbol() Currently we traverse all symbols of all modules to find the specified function for the specified module. But in reality, we just need to find the given module and then traverse all the symbols in it. Let's add a new parameter 'const char *modname' to function module_kallsyms_on_each_symbol(), then we can compare the module names directly in this function and call hook 'fn' after matching. If 'modname' is NULL, the symbols of all modules are still traversed for compatibility with other usage cases. Phase1: mod1-->mod2..(subsequent modules do not need to be compared) | Phase2: -->f1-->f2-->f3 Assuming that there are m modules, each module has n symbols on average, then the time complexity is reduced from O(m * n) to O(m) + O(n). Reviewed-by: Petr Mladek Acked-by: Song Liu Signed-off-by: Zhen Lei Signed-off-by: Jiri Olsa Acked-by: Miroslav Benes Reviewed-by: Luis Chamberlain Link: https://lore.kernel.org/r/20230116101009.23694-2-jolsa@kernel.org Signed-off-by: Alexei Starovoitov --- include/linux/module.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 8c5909c0076c..514bc81568c5 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -879,11 +879,13 @@ static inline bool module_sig_ok(struct module *module) #endif /* CONFIG_MODULE_SIG */ #if defined(CONFIG_MODULES) && defined(CONFIG_KALLSYMS) -int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data); #else -static inline int module_kallsyms_on_each_symbol(int (*fn)(void *, const char *, +static inline int module_kallsyms_on_each_symbol(const char *modname, + int (*fn)(void *, const char *, struct module *, unsigned long), void *data) { -- cgit v1.2.3 From eca0edaf6caa66b6eb26277a7dce5d7296cedfca Mon Sep 17 00:00:00 2001 From: Marcos Paulo de Souza Date: Fri, 3 Feb 2023 09:22:21 -0300 Subject: module.h: Document klp_modinfo struct using kdoc Previously the documentation existed only in Documentation/livepatch directory. Signed-off-by: Marcos Paulo de Souza Signed-off-by: Luis Chamberlain --- include/linux/module.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux/module.h') diff --git a/include/linux/module.h b/include/linux/module.h index 8c5909c0076c..6449ea59c074 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -352,6 +352,14 @@ struct mod_kallsyms { }; #ifdef CONFIG_LIVEPATCH +/** + * struct klp_modinfo - Elf information preserved from the livepatch module + * + * @hdr: Elf header + * @sechdrs: Section header table + * @secstrings: String table for the section headers + * @symndx: The symbol table section index + */ struct klp_modinfo { Elf_Ehdr hdr; Elf_Shdr *sechdrs; -- cgit v1.2.3