From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965552AbXDBOz3 (ORCPT ); Mon, 2 Apr 2007 10:55:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965558AbXDBOz2 (ORCPT ); Mon, 2 Apr 2007 10:55:28 -0400 Received: from mailhub.sw.ru ([195.214.233.200]:2410 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965552AbXDBOz0 (ORCPT ); Mon, 2 Apr 2007 10:55:26 -0400 Date: Mon, 2 Apr 2007 19:03:16 +0400 From: Alexey Dobriyan To: rusty@rustcorp.com.au, pmarques@grupopie.com Cc: linux-kernel@vger.kernel.org, devel@openvz.org Subject: [PATCH 5/5] Fix race between cat /proc/slab_allocators and rmmod Message-ID: <20070402150316.GE6735@localhost.sw.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Same story as with cat /proc/*/wchan race vs rmmod race, only /proc/slab_allocators want more info than just symbol name. Signed-off-by: Alexey Dobriyan --- include/linux/kallsyms.h | 6 ++++++ include/linux/module.h | 6 ++++++ kernel/kallsyms.c | 19 +++++++++++++++++++ kernel/module.c | 27 +++++++++++++++++++++++++++ mm/slab.c | 10 +++------- 5 files changed, 61 insertions(+), 7 deletions(-) --- a/include/linux/kallsyms.h +++ b/include/linux/kallsyms.h @@ -23,6 +23,7 @@ const char *kallsyms_lookup(unsigned lon char **modname, char *namebuf); int lookup_symbol_name(unsigned long addr, char *symname); +int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name); /* Replace "%s" in format with address, if found */ extern void __print_symbol(const char *fmt, unsigned long address); @@ -54,6 +55,11 @@ static inline int lookup_symbol_name(uns return -ERANGE; } +static inline int lookup_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) +{ + return -ERANGE; +} + /* Stupid that this does nothing, but I didn't create this mess. */ #define __print_symbol(fmt, addr) #endif /*CONFIG_KALLSYMS*/ --- a/include/linux/module.h +++ b/include/linux/module.h @@ -457,6 +457,7 @@ const char *module_address_lookup(unsign unsigned long *offset, char **modname); 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); /* For extable.c to search modules' exception tables. */ const struct exception_table_entry *search_module_extables(unsigned long addr); @@ -533,6 +534,11 @@ static inline int lookup_module_symbol_n return -ERANGE; } +static inline int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, unsigned long *offset, char *modname, char *name) +{ + return -ERANGE; +} + static inline int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *name, char *module_name, int *exported) --- a/kernel/kallsyms.c +++ b/kernel/kallsyms.c @@ -286,6 +286,25 @@ int lookup_symbol_name(unsigned long add return lookup_module_symbol_name(addr, symname); } +int lookup_symbol_attrs(unsigned long addr, unsigned long *size, + unsigned long *offset, char *modname, char *name) +{ + name[0] = '\0'; + name[KSYM_NAME_LEN] = '\0'; + + if (is_ksym_addr(addr)) { + unsigned long pos; + + pos = get_symbol_pos(addr, size, offset); + /* Grab name */ + kallsyms_expand_symbol(get_symbol_offset(pos), name); + modname[0] = '\0'; + return 0; + } + /* see if it's in a module */ + return lookup_module_symbol_attrs(addr, size, offset, modname, name); +} + /* Replace "%s" in format with address, or returns -errno. */ void __print_symbol(const char *fmt, unsigned long address) { --- a/kernel/module.c +++ b/kernel/module.c @@ -2145,6 +2145,33 @@ out: return -ERANGE; } +int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, + unsigned long *offset, char *modname, char *name) +{ + struct module *mod; + + mutex_lock(&module_mutex); + list_for_each_entry(mod, &modules, list) { + if (within(addr, mod->module_init, mod->init_size) || + within(addr, mod->module_core, mod->core_size)) { + const char *sym; + + sym = get_ksymbol(mod, addr, size, offset); + if (!sym) + goto out; + if (modname) + strlcpy(modname, mod->name, MODULE_NAME_LEN + 1); + if (name) + strlcpy(name, sym, KSYM_NAME_LEN + 1); + mutex_unlock(&module_mutex); + return 0; + } + } +out: + mutex_unlock(&module_mutex); + return -ERANGE; +} + int module_get_kallsym(unsigned int symnum, unsigned long *value, char *type, char *name, char *module_name, int *exported) { --- a/mm/slab.c +++ b/mm/slab.c @@ -4380,16 +4380,12 @@ static void handle_slab(unsigned long *n static void show_symbol(struct seq_file *m, unsigned long address) { #ifdef CONFIG_KALLSYMS - char *modname; - const char *name; unsigned long offset, size; - char namebuf[KSYM_NAME_LEN+1]; - - name = kallsyms_lookup(address, &size, &offset, &modname, namebuf); + char modname[MODULE_NAME_LEN + 1], name[KSYM_NAME_LEN + 1]; - if (name) { + if (lookup_symbol_attrs(address, &size, &offset, modname, name) == 0) { seq_printf(m, "%s+%#lx/%#lx", name, offset, size); - if (modname) + if (modname[0]) seq_printf(m, " [%s]", modname); return; }