diff options
| -rw-r--r-- | kernel/module.c | 144 |
1 files changed, 91 insertions, 53 deletions
diff --git a/kernel/module.c b/kernel/module.c index eb26b95a909b..567afa563ba5 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -55,6 +55,7 @@ #include <linux/async.h> #include <linux/percpu.h> #include <linux/kmemleak.h> +#include <linux/bsearch.h> #define CREATE_TRACE_POINTS #include <trace/events/module.h> @@ -279,36 +280,98 @@ bool each_symbol(each_symbol_fn_t *fn, void *data) } EXPORT_SYMBOL_GPL(each_symbol); -struct find_symbol_arg { - /* Input */ - const char *name; - bool gplok; - bool warn; +static int symbol_compare(const void *key, const void *elt) +{ + const char *str = key; + const struct kernel_symbol *sym = elt; + return strcmp(str, sym->name); +} - /* Output */ - struct module *owner; - const unsigned long *crc; +/* binary search on sorted symbols */ +static const struct kernel_symbol *find_symbol_in_kernel( + const char *name, + enum export_type *t, + const unsigned long **crc) +{ + struct kernel_symbol *sym; + enum export_type type; + unsigned int i; + + for (type = 0; type < ARRAY_SIZE(ksymtab); type++) { + sym = bsearch(name, ksymtab[type].syms, ksymtab[type].num_syms, + sizeof(struct kernel_symbol), symbol_compare); + if (sym) { + i = sym - ksymtab[type].syms; + *crc = symversion(ksymtab[type].crcs, i); + *t = type; + return sym; + } + } + + return NULL; +} + +/* linear search on unsorted symbols */ +static const struct kernel_symbol *find_symbol_in_module( + struct module *mod, + const char *name, + enum export_type *t, + const unsigned long **crc) +{ + struct ksymtab *symtab = mod->syms; const struct kernel_symbol *sym; -}; + enum export_type type; + unsigned int i; -static bool find_symbol_in_section(enum export_type type, - const struct kernel_symbol *sym, - const unsigned long *crc, - struct module *owner, - void *data) + for (type = 0; type < EXPORT_TYPE_MAX; type++) { + for (i = 0; i < symtab[type].num_syms; i++) { + sym = &symtab[type].syms[i]; + + if (strcmp(sym->name, name) == 0) { + *crc = symversion(symtab[type].crcs, i); + *t = type; + return sym; + } + } + } + + return NULL; +} + +/* Find a symbol and return it, along with, (optional) crc and + * (optional) module which owns it */ +const struct kernel_symbol *find_symbol(const char *name, + struct module **owner, + const unsigned long **crc, + bool gplok, + bool warn) { - struct find_symbol_arg *fsa = data; + struct module *mod = NULL; + const struct kernel_symbol *sym; + enum export_type type; + const unsigned long *crc_value; - if (strcmp(sym->name, fsa->name) != 0) - return false; + sym = find_symbol_in_kernel(name, &type, &crc_value); + if (sym) + goto found; + + list_for_each_entry_rcu(mod, &modules, list) { + sym = find_symbol_in_module(mod, name, &type, &crc_value); + if (sym) + goto found; + } + + DEBUGP("Failed to find symbol %s\n", name); + return NULL; - if (!fsa->gplok) { +found: + if (!gplok) { if (export_is_gpl_only(type)) - return false; - if (export_is_gpl_future(type) && fsa->warn) { + return NULL; + if (export_is_gpl_future(type) && warn) { printk(KERN_WARNING "Symbol %s is being used " "by a non-GPL module, which will not " - "be allowed in the future\n", fsa->name); + "be allowed in the future\n", name); printk(KERN_WARNING "Please see the file " "Documentation/feature-removal-schedule.txt " "in the kernel source tree for more details.\n"); @@ -316,9 +379,9 @@ static bool find_symbol_in_section(enum export_type type, } #ifdef CONFIG_UNUSED_SYMBOLS - if (export_is_unused(type) && fsa->warn) { + if (export_is_unused(type) && warn) { printk(KERN_WARNING "Symbol %s is marked as UNUSED, " - "however this module is using it.\n", fsa->name); + "however this module is using it.\n", name); printk(KERN_WARNING "This symbol will go away in the future.\n"); printk(KERN_WARNING @@ -329,36 +392,11 @@ static bool find_symbol_in_section(enum export_type type, } #endif - fsa->owner = owner; - fsa->crc = crc; - fsa->sym = sym; - return true; -} - -/* Find a symbol and return it, along with, (optional) crc and - * (optional) module which owns it */ -const struct kernel_symbol *find_symbol(const char *name, - struct module **owner, - const unsigned long **crc, - bool gplok, - bool warn) -{ - struct find_symbol_arg fsa; - - fsa.name = name; - fsa.gplok = gplok; - fsa.warn = warn; - - if (each_symbol(find_symbol_in_section, &fsa)) { - if (owner) - *owner = fsa.owner; - if (crc) - *crc = fsa.crc; - return fsa.sym; - } - - DEBUGP("Failed to find symbol %s\n", name); - return NULL; + if (owner) + *owner = mod; + if (crc) + *crc = crc_value; + return sym; } EXPORT_SYMBOL_GPL(find_symbol); |