diff options
| -rw-r--r-- | include/linux/module.h | 22 | ||||
| -rw-r--r-- | kernel/kallsyms.c | 11 | ||||
| -rw-r--r-- | kernel/module.c | 22 |
3 files changed, 30 insertions, 25 deletions
diff --git a/include/linux/module.h b/include/linux/module.h index c97bdb7..aedc06b 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -446,11 +446,14 @@ static inline void __module_get(struct module *module) __mod ? __mod->name : "kernel"; \ }) -/* For kallsyms to ask for address resolution. NULL means not found. */ -const char *module_address_lookup(unsigned long addr, - unsigned long *symbolsize, - unsigned long *offset, - char **modname); +/* For kallsyms to ask for address resolution. namebuf should be at + * least KSYM_NAME_LEN long: a pointer to namebuf is returned if + * found, otherwise NULL. */ +char *module_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, + char *namebuf); int lookup_module_symbol_name(unsigned long addr, char *symname); int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); @@ -516,10 +519,11 @@ static inline void module_put(struct module *module) #define module_name(mod) "kernel" /* For kallsyms to ask for address resolution. NULL means not found. */ -static inline const char *module_address_lookup(unsigned long addr, - unsigned long *symbolsize, - unsigned long *offset, - char **modname) +static inline char *module_address_lookup(unsigned long addr, + unsigned long *symbolsize, + unsigned long *offset, + char **modname, + char *namebuf) { return NULL; } diff --git a/kernel/kallsyms.c b/kernel/kallsyms.c index 2fc2581..7dadc71 100644 --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -233,10 +233,11 @@ static unsigned long get_symbol_pos(unsigned long addr, int kallsyms_lookup_size_offset(unsigned long addr, unsigned long *symbolsize, unsigned long *offset) { + char namebuf[KSYM_NAME_LEN]; if (is_ksym_addr(addr)) return !!get_symbol_pos(addr, symbolsize, offset); - return !!module_address_lookup(addr, symbolsize, offset, NULL); + return !!module_address_lookup(addr, symbolsize, offset, NULL, namebuf); } /* @@ -251,8 +252,6 @@ const char *kallsyms_lookup(unsigned long addr, unsigned long *offset, char **modname, char *namebuf) { - const char *msym; - namebuf[KSYM_NAME_LEN - 1] = 0; namebuf[0] = 0; @@ -268,10 +267,8 @@ const char *kallsyms_lookup(unsigned long addr, } /* see if it's in a module */ - msym = module_address_lookup(addr, symbolsize, offset, modname); - if (msym) - return strncpy(namebuf, msym, KSYM_NAME_LEN - 1); - + return module_address_lookup(addr, symbolsize, offset, modname, + namebuf); return NULL; } diff --git a/kernel/module.c b/kernel/module.c index 12067ff..e814cd7 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -2230,14 +2230,13 @@ static const char *get_ksymbol(struct module *mod, return mod->strtab + mod->symtab[best].st_name; } -/* For kallsyms to ask for address resolution. NULL means not found. - We don't lock, as this is used for oops resolution and races are a - lesser concern. */ -/* FIXME: Risky: returns a pointer into a module w/o lock */ -const char *module_address_lookup(unsigned long addr, - unsigned long *size, - unsigned long *offset, - char **modname) +/* For kallsyms to ask for address resolution. NULL means not found. Careful + * not to lock to avoid deadlock on oopses, simply disable preemption. */ +char *module_address_lookup(unsigned long addr, + unsigned long *size, + unsigned long *offset, + char **modname, + char *namebuf) { struct module *mod; const char *ret = NULL; @@ -2252,8 +2251,13 @@ const char *module_address_lookup(unsigned long addr, break; } } + /* Make a copy in here where it's safe */ + if (ret) { + strncpy(namebuf, ret, KSYM_NAME_LEN - 1); + ret = namebuf; + } preempt_enable(); - return ret; + return (char *)ret; } int lookup_module_symbol_name(unsigned long addr, char *symname) |