diff options
| author | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2011-05-10 20:52:07 +0200 |
|---|---|---|
| committer | Stefan Richter <stefanr@s5r6.in-berlin.de> | 2011-05-10 22:50:41 +0200 |
| commit | 020abf03cd659388f94cb328e1e1df0656e0d7ff (patch) | |
| tree | 40d05011708ad1b4a05928d167eb120420581aa6 /kernel/module.c | |
| parent | 0ff8fbc61727c926883eec381fbd3d32d1fab504 (diff) | |
| parent | 693d92a1bbc9e42681c42ed190bd42b636ca876f (diff) | |
Merge tag 'v2.6.39-rc7'
in order to pull in changes in drivers/media/dvb/firewire/ and
sound/firewire/.
Diffstat (limited to 'kernel/module.c')
| -rw-r--r-- | kernel/module.c | 197 |
1 files changed, 182 insertions, 15 deletions
diff --git a/kernel/module.c b/kernel/module.c index d190664f25f..d5938a5c19c 100644 --- a/kernel/module.c +++ b/kernel/module.c @@ -56,6 +56,7 @@ #include <linux/percpu.h> #include <linux/kmemleak.h> #include <linux/jump_label.h> +#include <linux/pfn.h> #define CREATE_TRACE_POINTS #include <trace/events/module.h> @@ -70,6 +71,26 @@ #define ARCH_SHF_SMALL 0 #endif +/* + * Modules' sections will be aligned on page boundaries + * to ensure complete separation of code and data, but + * only when CONFIG_DEBUG_SET_MODULE_RONX=y + */ +#ifdef CONFIG_DEBUG_SET_MODULE_RONX +# define debug_align(X) ALIGN(X, PAGE_SIZE) +#else +# define debug_align(X) (X) +#endif + +/* + * Given BASE and SIZE this macro calculates the number of pages the + * memory regions occupies + */ +#define MOD_NUMBER_OF_PAGES(BASE, SIZE) (((SIZE) > 0) ? \ + (PFN_DOWN((unsigned long)(BASE) + (SIZE) - 1) - \ + PFN_DOWN((unsigned long)BASE) + 1) \ + : (0UL)) + /* If this is set, the section belongs in the init part of the module */ #define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1)) @@ -788,7 +809,7 @@ SYSCALL_DEFINE2(delete_module, const char __user *, name_user, wait_for_zero_refcount(mod); mutex_unlock(&module_mutex); - /* Final destruction now noone is using it. */ + /* Final destruction now no one is using it. */ if (mod->exit != NULL) mod->exit(); blocking_notifier_call_chain(&module_notify_list, @@ -1147,7 +1168,7 @@ static ssize_t module_sect_show(struct module_attribute *mattr, { struct module_sect_attr *sattr = container_of(mattr, struct module_sect_attr, mattr); - return sprintf(buf, "0x%lx\n", sattr->address); + return sprintf(buf, "0x%pK\n", (void *)sattr->address); } static void free_sect_attrs(struct module_sect_attrs *sect_attrs) @@ -1542,6 +1563,115 @@ static int __unlink_module(void *_mod) return 0; } +#ifdef CONFIG_DEBUG_SET_MODULE_RONX +/* + * LKM RO/NX protection: protect module's text/ro-data + * from modification and any data from execution. + */ +void set_page_attributes(void *start, void *end, int (*set)(unsigned long start, int num_pages)) +{ + unsigned long begin_pfn = PFN_DOWN((unsigned long)start); + unsigned long end_pfn = PFN_DOWN((unsigned long)end); + + if (end_pfn > begin_pfn) + set(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn); +} + +static void set_section_ro_nx(void *base, + unsigned long text_size, + unsigned long ro_size, + unsigned long total_size) +{ + /* begin and end PFNs of the current subsection */ + unsigned long begin_pfn; + unsigned long end_pfn; + + /* + * Set RO for module text and RO-data: + * - Always protect first page. + * - Do not protect last partial page. + */ + if (ro_size > 0) + set_page_attributes(base, base + ro_size, set_memory_ro); + + /* + * Set NX permissions for module data: + * - Do not protect first partial page. + * - Always protect last page. + */ + if (total_size > text_size) { + begin_pfn = PFN_UP((unsigned long)base + text_size); + end_pfn = PFN_UP((unsigned long)base + total_size); + if (end_pfn > begin_pfn) + set_memory_nx(begin_pfn << PAGE_SHIFT, end_pfn - begin_pfn); + } +} + +/* Setting memory back to RW+NX before releasing it */ +void unset_section_ro_nx(struct module *mod, void *module_region) +{ + unsigned long total_pages; + + if (mod->module_core == module_region) { + /* Set core as NX+RW */ + total_pages = MOD_NUMBER_OF_PAGES(mod->module_core, mod->core_size); + set_memory_nx((unsigned long)mod->module_core, total_pages); + set_memory_rw((unsigned long)mod->module_core, total_pages); + + } else if (mod->module_init == module_region) { + /* Set init as NX+RW */ + total_pages = MOD_NUMBER_OF_PAGES(mod->module_init, mod->init_size); + set_memory_nx((unsigned long)mod->module_init, total_pages); + set_memory_rw((unsigned long)mod->module_init, total_pages); + } +} + +/* Iterate through all modules and set each module's text as RW */ +void set_all_modules_text_rw() +{ + struct module *mod; + + mutex_lock(&module_mutex); + list_for_each_entry_rcu(mod, &modules, list) { + if ((mod->module_core) && (mod->core_text_size)) { + set_page_attributes(mod->module_core, + mod->module_core + mod->core_text_size, + set_memory_rw); + } + if ((mod->module_init) && (mod->init_text_size)) { + set_page_attributes(mod->module_init, + mod->module_init + mod->init_text_size, + set_memory_rw); + } + } + mutex_unlock(&module_mutex); +} + +/* Iterate through all modules and set each module's text as RO */ +void set_all_modules_text_ro() +{ + struct module *mod; + + mutex_lock(&module_mutex); + list_for_each_entry_rcu(mod, &modules, list) { + if ((mod->module_core) && (mod->core_text_size)) { + set_page_attributes(mod->module_core, + mod->module_core + mod->core_text_size, + set_memory_ro); + } + if ((mod->module_init) && (mod->init_text_size)) { + set_page_attributes(mod->module_init, + mod->module_init + mod->init_text_size, + set_memory_ro); + } + } + mutex_unlock(&module_mutex); +} +#else +static inline void set_section_ro_nx(void *base, unsigned long text_size, unsigned long ro_size, unsigned long total_size) { } +static inline void unset_section_ro_nx(struct module *mod, void *module_region) { } +#endif + /* Free a module, remove from lists, etc. */ static void free_module(struct module *mod) { @@ -1566,6 +1696,7 @@ static void free_module(struct module *mod) destroy_params(mod->kp, mod->num_kp); /* This may be NULL, but that's OK */ + unset_section_ro_nx(mod, mod->module_init); module_free(mod, mod->module_init); kfree(mod->args); percpu_modfree(mod); @@ -1574,6 +1705,7 @@ static void free_module(struct module *mod) lockdep_free_key_range(mod->module_core, mod->core_size); /* Finally, free the core (containing the module structure) */ + unset_section_ro_nx(mod, mod->module_core); module_free(mod, mod->module_core); #ifdef CONFIG_MPU @@ -1777,8 +1909,19 @@ static void layout_sections(struct module *mod, struct load_info *info) s->sh_entsize = get_offset(mod, &mod->core_size, s, i); DEBUGP("\t%s\n", name); } - if (m == 0) + switch (m) { + case 0: /* executable */ + mod->core_size = debug_align(mod->core_size); mod->core_text_size = mod->core_size; + break; + case 1: /* RO: text and ro-data */ + mod->core_size = debug_align(mod->core_size); + mod->core_ro_size = mod->core_size; + break; + case 3: /* whole core */ + mod->core_size = debug_align(mod->core_size); + break; + } } DEBUGP("Init section allocation order:\n"); @@ -1796,8 +1939,19 @@ static void layout_sections(struct module *mod, struct load_info *info) | INIT_OFFSET_MASK); DEBUGP("\t%s\n", sname); } - if (m == 0) + switch (m) { + case 0: /* executable */ + mod->init_size = debug_align(mod->init_size); mod->init_text_size = mod->init_size; + break; + case 1: /* RO: text and ro-data */ + mod->init_size = debug_align(mod->init_size); + mod->init_ro_size = mod->init_size; + break; + case 3: /* whole init */ + mod->init_size = debug_align(mod->init_size); + break; + } } } @@ -2306,9 +2460,9 @@ static void find_module_sections(struct module *mod, struct load_info *info) #endif #ifdef CONFIG_TRACEPOINTS - mod->tracepoints = section_objs(info, "__tracepoints", - sizeof(*mod->tracepoints), - &mod->num_tracepoints); + mod->tracepoints_ptrs = section_objs(info, "__tracepoints_ptrs", + sizeof(*mod->tracepoints_ptrs), + &mod->num_tracepoints); #endif #ifdef HAVE_JUMP_LABEL mod->jump_entries = section_objs(info, "__jump_table", @@ -2623,7 +2777,7 @@ static struct module *load_module(void __user *umod, mod->state = MODULE_STATE_COMING; /* Now sew it into the lists so we can get lockdep and oops - * info during argument parsing. Noone should access us, since + * info during argument parsing. No one should access us, since * strong_try_module_get() will fail. * lockdep/oops can run asynchronous, so use the RCU list insertion * function to insert in a way safe to concurrent readers. @@ -2722,6 +2876,18 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, blocking_notifier_call_chain(&module_notify_list, MODULE_STATE_COMING, mod); + /* Set RO and NX regions for core */ + set_section_ro_nx(mod->module_core, + mod->core_text_size, + mod->core_ro_size, + mod->core_size); + + /* Set RO and NX regions for init */ + set_section_ro_nx(mod->module_init, + mod->init_text_size, + mod->init_ro_size, + mod->init_size); + do_mod_ctors(mod); /* Start the module */ if (mod->init != NULL) @@ -2765,6 +2931,7 @@ SYSCALL_DEFINE3(init_module, void __user *, umod, mod->symtab = mod->core_symtab; mod->strtab = mod->core_strtab; #endif + unset_section_ro_nx(mod, mod->module_init); module_free(mod, mod->module_init); mod->module_init = NULL; mod->init_size = 0; @@ -2804,7 +2971,7 @@ static const char *get_ksymbol(struct module *mod, else nextval = (unsigned long)mod->module_core+mod->core_text_size; - /* Scan for closest preceeding symbol, and next symbol. (ELF + /* Scan for closest preceding symbol, and next symbol. (ELF starts real symbols at 1). */ for (i = 1; i < mod->num_symtab; i++) { if (mod->symtab[i].st_shndx == SHN_UNDEF) @@ -3057,7 +3224,7 @@ static int m_show(struct seq_file *m, void *p) mod->state == MODULE_STATE_COMING ? "Loading": "Live"); /* Used by oprofile and other similar tools. */ - seq_printf(m, " 0x%p", mod->module_core); + seq_printf(m, " 0x%pK", mod->module_core); /* Taints info */ if (mod->taints) @@ -3226,7 +3393,7 @@ void module_layout(struct module *mod, struct modversion_info *ver, struct kernel_param *kp, struct kernel_symbol *ks, - struct tracepoint *tp) + struct tracepoint * const *tp) { } EXPORT_SYMBOL(module_layout); @@ -3240,8 +3407,8 @@ void module_update_tracepoints(void) mutex_lock(&module_mutex); list_for_each_entry(mod, &modules, list) if (!mod->taints) - tracepoint_update_probe_range(mod->tracepoints, - mod->tracepoints + mod->num_tracepoints); + tracepoint_update_probe_range(mod->tracepoints_ptrs, + mod->tracepoints_ptrs + mod->num_tracepoints); mutex_unlock(&module_mutex); } @@ -3265,8 +3432,8 @@ int module_get_iter_tracepoints(struct tracepoint_iter *iter) else if (iter_mod > iter->module) iter->tracepoint = NULL; found = tracepoint_get_iter_range(&iter->tracepoint, - iter_mod->tracepoints, - iter_mod->tracepoints + iter_mod->tracepoints_ptrs, + iter_mod->tracepoints_ptrs + iter_mod->num_tracepoints); if (found) { iter->module = iter_mod; |
