From 3a611c3cfba2106aed3187b90903855e776e2761 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 27 Jul 2014 07:23:01 +0930 Subject: modules: Fix build error in moduleloader.h Fengguang Wu's build bot detected that if moduleloader.h is included in a C file (used by ftrace and kprobes to access module_alloc() when available), that it can fail to build if CONFIG_MODULES and CONFIG_MODULES_USE_ELF_REL is not defined. This is because there's a printk() that dereferences struct module to print the name of the module. But as struct module does not exist when CONFIG_MODULES is not defined we get this error: include/linux/moduleloader.h: In function 'apply_relocate': >> include/linux/moduleloader.h:48:63: error: dereferencing pointer to >> incomplete type printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name); ^ Reported-by: kbuild test robot Based-on-the-true-story-by: Steven Rostedt Confirms-rustys-story-ends-the-same-by: Steven Rostedt Signed-off-by: Rusty Russell --- include/linux/moduleloader.h | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'include') diff --git a/include/linux/moduleloader.h b/include/linux/moduleloader.h index 560ca53a75f..7eeb9bbfb81 100644 --- a/include/linux/moduleloader.h +++ b/include/linux/moduleloader.h @@ -45,7 +45,8 @@ static inline int apply_relocate(Elf_Shdr *sechdrs, unsigned int relsec, struct module *me) { - printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name); + printk(KERN_ERR "module %s: REL relocation unsupported\n", + module_name(me)); return -ENOEXEC; } #endif @@ -67,7 +68,8 @@ static inline int apply_relocate_add(Elf_Shdr *sechdrs, unsigned int relsec, struct module *me) { - printk(KERN_ERR "module %s: REL relocation unsupported\n", me->name); + printk(KERN_ERR "module %s: REL relocation unsupported\n", + module_name(me)); return -ENOEXEC; } #endif -- cgit v1.2.3-70-g09d2 From 9b20a352d78a7651aa68a9220f77ccb03009d892 Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Sun, 27 Jul 2014 07:24:01 +0930 Subject: module: add within_module() function It is just a small optimization that allows to replace few occurrences of within_module_init() || within_module_core() with a single call. Signed-off-by: Petr Mladek Signed-off-by: Rusty Russell --- include/linux/module.h | 5 +++++ kernel/module.c | 12 ++++-------- 2 files changed, 9 insertions(+), 8 deletions(-) (limited to 'include') diff --git a/include/linux/module.h b/include/linux/module.h index f520a767c86..61d8fb2d087 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -408,6 +408,11 @@ static inline int within_module_init(unsigned long addr, const struct module *mo addr < (unsigned long)mod->module_init + mod->init_size; } +static inline int within_module(unsigned long addr, const struct module *mod) +{ + return within_module_init(addr, mod) || within_module_core(addr, mod); +} + /* Search for module by name: must hold module_mutex. */ struct module *find_module(const char *name); diff --git a/kernel/module.c b/kernel/module.c index 81e727cf6df..e87fdd2fc3c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -3448,8 +3448,7 @@ const char *module_address_lookup(unsigned long addr, list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; - if (within_module_init(addr, mod) || - within_module_core(addr, mod)) { + if (within_module(addr, mod)) { if (modname) *modname = mod->name; ret = get_ksymbol(mod, addr, size, offset); @@ -3473,8 +3472,7 @@ int lookup_module_symbol_name(unsigned long addr, char *symname) list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; - if (within_module_init(addr, mod) || - within_module_core(addr, mod)) { + if (within_module(addr, mod)) { const char *sym; sym = get_ksymbol(mod, addr, NULL, NULL); @@ -3499,8 +3497,7 @@ int lookup_module_symbol_attrs(unsigned long addr, unsigned long *size, list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; - if (within_module_init(addr, mod) || - within_module_core(addr, mod)) { + if (within_module(addr, mod)) { const char *sym; sym = get_ksymbol(mod, addr, size, offset); @@ -3764,8 +3761,7 @@ struct module *__module_address(unsigned long addr) list_for_each_entry_rcu(mod, &modules, list) { if (mod->state == MODULE_STATE_UNFORMED) continue; - if (within_module_core(addr, mod) - || within_module_init(addr, mod)) + if (within_module(addr, mod)) return mod; } return NULL; -- cgit v1.2.3-70-g09d2 From 76681c8faa07f9e07caa3cc69f235c8719b2a6ea Mon Sep 17 00:00:00 2001 From: Petr Mladek Date: Sun, 27 Jul 2014 07:25:01 +0930 Subject: module: return bool from within_module*() The within_module*() functions return only true or false. Let's use bool as the return type. Note that it should not change kABI because these are inline functions. Signed-off-by: Petr Mladek Signed-off-by: Rusty Russell --- include/linux/module.h | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'include') diff --git a/include/linux/module.h b/include/linux/module.h index 61d8fb2d087..71f282a4e30 100644 --- a/include/linux/module.h +++ b/include/linux/module.h @@ -396,19 +396,21 @@ bool is_module_address(unsigned long addr); bool is_module_percpu_address(unsigned long addr); bool is_module_text_address(unsigned long addr); -static inline int within_module_core(unsigned long addr, const struct module *mod) +static inline bool within_module_core(unsigned long addr, + const struct module *mod) { return (unsigned long)mod->module_core <= addr && addr < (unsigned long)mod->module_core + mod->core_size; } -static inline int within_module_init(unsigned long addr, const struct module *mod) +static inline bool within_module_init(unsigned long addr, + const struct module *mod) { return (unsigned long)mod->module_init <= addr && addr < (unsigned long)mod->module_init + mod->init_size; } -static inline int within_module(unsigned long addr, const struct module *mod) +static inline bool within_module(unsigned long addr, const struct module *mod) { return within_module_init(addr, mod) || within_module_core(addr, mod); } -- cgit v1.2.3-70-g09d2 From 37549e94c77a94a9c32b5ae3313a3801cb66adf9 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Sun, 27 Jul 2014 07:26:01 +0930 Subject: sysfs: disallow world-writable files. This check was introduced in 2006 by Alexey Dobriyan (9774a1f54f173) for module parameters; we removed it when we unified the check into VERIFY_OCTAL_PERMISSIONS() as sysfs didn't have the same requirement. Now all those users are fixed, reintroduce it. Cc: Alexey Dobriyan Cc: Dave Jones Cc: Joe Perches Signed-off-by: Rusty Russell --- include/linux/kernel.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'include') diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 4c52907a6d8..43e1c6a9683 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -849,5 +849,7 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } /* User perms >= group perms >= other perms */ \ BUILD_BUG_ON_ZERO(((perms) >> 6) < (((perms) >> 3) & 7)) + \ BUILD_BUG_ON_ZERO((((perms) >> 3) & 7) < ((perms) & 7)) + \ + /* Other writable? Generally considered a bad idea. */ \ + BUILD_BUG_ON_ZERO((perms) & 2) + \ (perms)) #endif -- cgit v1.2.3-70-g09d2