From 3cd60866d46050d14734cbbac41b00c8d3e51d61 Mon Sep 17 00:00:00 2001 From: Rasmus Villemoes Date: Thu, 29 Sep 2022 14:10:39 +0200 Subject: module: remove redundant module_sysfs_initialized variable The variable module_sysfs_initialized is used for checking whether module_kset has been initialized. Checking module_kset itself works just fine for that. This is a leftover from commit 7405c1e15edf ("kset: convert /sys/module to use kset_create"). Signed-off-by: Rasmus Villemoes Reviewed-by: Miroslav Benes [mcgrof: adjusted commit log as suggested by Christophe Leroy] Signed-off-by: Luis Chamberlain --- include/linux/module.h | 1 - 1 file changed, 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/module.h b/include/linux/module.h index ec61fb53979a..676614d56c25 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -827,7 +827,6 @@ void *dereference_module_function_descriptor(struct module *mod, void *ptr) #ifdef CONFIG_SYSFS extern struct kset *module_kset; extern struct kobj_type module_ktype; -extern int module_sysfs_initialized; #endif /* CONFIG_SYSFS */ #define symbol_request(x) try_then_request_module(symbol_get(x), "symbol:" #x) -- cgit From 4dc533e0f2c04174e1ae4aa98e7cffc1c04b9998 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Wed, 2 Nov 2022 16:49:17 +0800 Subject: kallsyms: Add helper kallsyms_on_each_match_symbol() Function kallsyms_on_each_symbol() traverses all symbols and submits each symbol to the hook 'fn' for judgment and processing. For some cases, the hook actually only handles the matched symbol, such as livepatch. Because all symbols are currently sorted by name, all the symbols with the same name are clustered together. Function kallsyms_lookup_names() gets the start and end positions of the set corresponding to the specified name. So we can easily and quickly traverse all the matches. The test results are as follows (twice): (x86) kallsyms_on_each_match_symbol: 7454, 7984 kallsyms_on_each_symbol : 11733809, 11785803 kallsyms_on_each_match_symbol() consumes only 0.066% of kallsyms_on_each_symbol()'s time. In other words, 1523x better performance. Signed-off-by: Zhen Lei Signed-off-by: Luis Chamberlain --- include/linux/kallsyms.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'include/linux') diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 649faac31ddb..0cd33be7142a 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -69,6 +69,8 @@ static inline void *dereference_symbol_descriptor(void *ptr) int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data); +int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), + const char *name, void *data); /* Lookup the address for a symbol. Returns 0 if not found. */ unsigned long kallsyms_lookup_name(const char *name); @@ -168,6 +170,12 @@ static inline int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct { return -EOPNOTSUPP; } + +static inline int kallsyms_on_each_match_symbol(int (*fn)(void *, unsigned long), + const char *name, void *data) +{ + return -EOPNOTSUPP; +} #endif /*CONFIG_KALLSYMS*/ static inline void print_ip_sym(const char *loglvl, unsigned long ip) -- cgit From 30f3bb09778de64ef9f23fb4bb5f868c4728a071 Mon Sep 17 00:00:00 2001 From: Zhen Lei Date: Tue, 15 Nov 2022 16:33:48 +0800 Subject: kallsyms: Add self-test facility Added test cases for basic functions and performance of functions kallsyms_lookup_name(), kallsyms_on_each_symbol() and kallsyms_on_each_match_symbol(). It also calculates the compression rate of the kallsyms compression algorithm for the current symbol set. The basic functions test begins by testing a set of symbols whose address values are known. Then, traverse all symbol addresses and find the corresponding symbol name based on the address. It's impossible to determine whether these addresses are correct, but we can use the above three functions along with the addresses to test each other. Due to the traversal operation of kallsyms_on_each_symbol() is too slow, only 60 symbols can be tested in one second, so let it test on average once every 128 symbols. The other two functions validate all symbols. If the basic functions test is passed, print only performance test results. If the test fails, print error information, but do not perform subsequent performance tests. Start self-test automatically after system startup if CONFIG_KALLSYMS_SELFTEST=y. Example of output content: (prefix 'kallsyms_selftest:' is omitted start --------------------------------------------------------- | nr_symbols | compressed size | original size | ratio(%) | |---------------------------------------------------------| | 107543 | 1357912 | 2407433 | 56.40 | --------------------------------------------------------- kallsyms_lookup_name() looked up 107543 symbols The time spent on each symbol is (ns): min=630, max=35295, avg=7353 kallsyms_on_each_symbol() traverse all: 11782628 ns kallsyms_on_each_match_symbol() traverse all: 9261 ns finish Signed-off-by: Zhen Lei Signed-off-by: Luis Chamberlain --- include/linux/kallsyms.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/linux') diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h index 0cd33be7142a..0065209cc004 100644 --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -66,6 +66,7 @@ static inline void *dereference_symbol_descriptor(void *ptr) } #ifdef CONFIG_KALLSYMS +unsigned long kallsyms_sym_address(int idx); int kallsyms_on_each_symbol(int (*fn)(void *, const char *, struct module *, unsigned long), void *data); -- cgit