External callers of the module page attribute change functions now need to have the text_mutex. Enforce that with lockdep assertions.
Signed-off-by: Josh Poimboeuf <[email protected]> --- kernel/module.c | 27 +++++++++++++++++++++------ 1 file changed, 21 insertions(+), 6 deletions(-) diff --git a/kernel/module.c b/kernel/module.c index 6e6712b3aaf5..e43a90ee2d23 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -64,6 +64,7 @@ #include <linux/bsearch.h> #include <linux/dynamic_debug.h> #include <linux/audit.h> +#include <linux/memory.h> #include <uapi/linux/module.h> #include "module-internal.h" @@ -1943,6 +1944,8 @@ static void frob_writable_data(const struct module_layout *layout, /* livepatching wants to disable read-only so it can frob module. */ void module_disable_ro(const struct module *mod) { + lockdep_assert_held(&text_mutex); + if (!rodata_enabled) return; @@ -1953,7 +1956,7 @@ void module_disable_ro(const struct module *mod) frob_rodata(&mod->init_layout, set_memory_rw); } -void module_enable_ro(const struct module *mod, bool after_init) +void __module_enable_ro(const struct module *mod, bool after_init) { if (!rodata_enabled) return; @@ -1974,7 +1977,14 @@ void module_enable_ro(const struct module *mod, bool after_init) frob_ro_after_init(&mod->core_layout, set_memory_ro); } -static void module_enable_nx(const struct module *mod) +void module_enable_ro(const struct module *mod, bool after_init) +{ + lockdep_assert_held(&text_mutex); + + __module_enable_ro(mod, after_init); +} + +static void __module_enable_nx(const struct module *mod) { frob_rodata(&mod->core_layout, set_memory_nx); frob_ro_after_init(&mod->core_layout, set_memory_nx); @@ -1988,6 +1998,8 @@ void set_all_modules_text_rw(void) { struct module *mod; + lockdep_assert_held(&text_mutex); + if (!rodata_enabled) return; @@ -2007,6 +2019,8 @@ void set_all_modules_text_ro(void) { struct module *mod; + lockdep_assert_held(&text_mutex); + if (!rodata_enabled) return; @@ -2027,7 +2041,8 @@ void set_all_modules_text_ro(void) mutex_unlock(&module_mutex); } #else -static void module_enable_nx(const struct module *mod) { } +static void __module_enable_ro(const struct module *mod, bool after_init) { } +static void __module_enable_nx(const struct module *mod) { } #endif #ifdef CONFIG_LIVEPATCH @@ -3519,7 +3534,7 @@ static noinline int do_init_module(struct module *mod) /* Switch to core kallsyms now init is done: kallsyms may be walking! */ rcu_assign_pointer(mod->kallsyms, &mod->core_kallsyms); #endif - module_enable_ro(mod, true); + __module_enable_ro(mod, true); mod_tree_remove_init(mod); module_arch_freeing_init(mod); mod->init_layout.base = NULL; @@ -3626,8 +3641,8 @@ static int complete_formation(struct module *mod, struct load_info *info) /* This relies on module_mutex for list integrity. */ module_bug_finalize(info->hdr, info->sechdrs, mod); - module_enable_ro(mod, false); - module_enable_nx(mod); + __module_enable_ro(mod, false); + __module_enable_nx(mod); /* Mark state as coming so strong_try_module_get() ignores us, * but kallsyms etc. can see us. */ -- 2.20.1
