#include <linux/rculist.h>
#include <asm/uaccess.h>
#include <asm/cacheflush.h>
+#include <asm/mmu_context.h>
#include <linux/license.h>
#include <asm/sections.h>
#include <linux/tracepoint.h>
#include <linux/percpu.h>
#include <linux/kmemleak.h>
+#define CREATE_TRACE_POINTS
+#include <trace/events/module.h>
+
#if 0
#define DEBUGP printk
#else
/* If this is set, the section belongs in the init part of the module */
#define INIT_OFFSET_MASK (1UL << (BITS_PER_LONG-1))
-/* List of modules, protected by module_mutex or preempt_disable
+/*
+ * Mutex protects:
+ * 1) List of modules (also safely readable with preempt_disable),
+ * 2) module_use links,
+ * 3) module_addr_min/module_addr_max.
* (delete uses stop_machine/add uses RCU list operations). */
DEFINE_MUTEX(module_mutex);
EXPORT_SYMBOL_GPL(module_mutex);
static LIST_HEAD(modules);
+#ifdef CONFIG_KGDB_KDB
+struct list_head *kdb_modules = &modules; /* kdb needs the list of modules */
+#endif /* CONFIG_KGDB_KDB */
+
/* Block module loading/unloading? */
int modules_disabled = 0;
static BLOCKING_NOTIFIER_HEAD(module_notify_list);
-/* Bounds of module allocation, for speeding __module_address */
+/* Bounds of module allocation, for speeding __module_address.
+ * Protected by module_mutex. */
static unsigned long module_addr_min = -1UL, module_addr_max = 0;
int register_module_notifier(struct notifier_block * nb)
extern const struct kernel_symbol __stop___ksymtab_gpl[];
extern const struct kernel_symbol __start___ksymtab_gpl_future[];
extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
-extern const struct kernel_symbol __start___ksymtab_gpl_future[];
-extern const struct kernel_symbol __stop___ksymtab_gpl_future[];
extern const unsigned long __start___kcrctab[];
extern const unsigned long __start___kcrctab_gpl[];
extern const unsigned long __start___kcrctab_gpl_future[];
}
/* Find a symbol and return it, along with, (optional) crc and
- * (optional) module which owns it */
+ * (optional) module which owns it. Needs preempt disabled or module_mutex. */
const struct kernel_symbol *find_symbol(const char *name,
struct module **owner,
const unsigned long **crc,
#ifdef CONFIG_SMP
-#ifdef CONFIG_HAVE_DYNAMIC_PER_CPU_AREA
-
-static void *percpu_modalloc(unsigned long size, unsigned long align,
- const char *name)
+static inline void __percpu *mod_percpu(struct module *mod)
{
- void *ptr;
+ return mod->percpu;
+}
+static int percpu_modalloc(struct module *mod,
+ unsigned long size, unsigned long align)
+{
if (align > PAGE_SIZE) {
printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
- name, align, PAGE_SIZE);
+ mod->name, align, PAGE_SIZE);
align = PAGE_SIZE;
}
- ptr = __alloc_reserved_percpu(size, align);
- if (!ptr)
+ mod->percpu = __alloc_reserved_percpu(size, align);
+ if (!mod->percpu) {
printk(KERN_WARNING
"Could not allocate %lu bytes percpu data\n", size);
- return ptr;
-}
-
-static void percpu_modfree(void *freeme)
-{
- free_percpu(freeme);
-}
-
-#else /* ... !CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
-
-/* Number of blocks used and allocated. */
-static unsigned int pcpu_num_used, pcpu_num_allocated;
-/* Size of each block. -ve means used. */
-static int *pcpu_size;
-
-static int split_block(unsigned int i, unsigned short size)
-{
- /* Reallocation required? */
- if (pcpu_num_used + 1 > pcpu_num_allocated) {
- int *new;
-
- new = krealloc(pcpu_size, sizeof(new[0])*pcpu_num_allocated*2,
- GFP_KERNEL);
- if (!new)
- return 0;
-
- pcpu_num_allocated *= 2;
- pcpu_size = new;
+ return -ENOMEM;
}
-
- /* Insert a new subblock */
- memmove(&pcpu_size[i+1], &pcpu_size[i],
- sizeof(pcpu_size[0]) * (pcpu_num_used - i));
- pcpu_num_used++;
-
- pcpu_size[i+1] -= size;
- pcpu_size[i] = size;
- return 1;
+ mod->percpu_size = size;
+ return 0;
}
-static inline unsigned int block_size(int val)
+static void percpu_modfree(struct module *mod)
{
- if (val < 0)
- return -val;
- return val;
+ free_percpu(mod->percpu);
}
-static void *percpu_modalloc(unsigned long size, unsigned long align,
- const char *name)
+static unsigned int find_pcpusec(Elf_Ehdr *hdr,
+ Elf_Shdr *sechdrs,
+ const char *secstrings)
{
- unsigned long extra;
- unsigned int i;
- void *ptr;
- int cpu;
-
- if (align > PAGE_SIZE) {
- printk(KERN_WARNING "%s: per-cpu alignment %li > %li\n",
- name, align, PAGE_SIZE);
- align = PAGE_SIZE;
- }
-
- ptr = __per_cpu_start;
- for (i = 0; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
- /* Extra for alignment requirement. */
- extra = ALIGN((unsigned long)ptr, align) - (unsigned long)ptr;
- BUG_ON(i == 0 && extra != 0);
-
- if (pcpu_size[i] < 0 || pcpu_size[i] < extra + size)
- continue;
-
- /* Transfer extra to previous block. */
- if (pcpu_size[i-1] < 0)
- pcpu_size[i-1] -= extra;
- else
- pcpu_size[i-1] += extra;
- pcpu_size[i] -= extra;
- ptr += extra;
-
- /* Split block if warranted */
- if (pcpu_size[i] - size > sizeof(unsigned long))
- if (!split_block(i, size))
- return NULL;
-
- /* add the per-cpu scanning areas */
- for_each_possible_cpu(cpu)
- kmemleak_alloc(ptr + per_cpu_offset(cpu), size, 0,
- GFP_KERNEL);
-
- /* Mark allocated */
- pcpu_size[i] = -pcpu_size[i];
- return ptr;
- }
-
- printk(KERN_WARNING "Could not allocate %lu bytes percpu data\n",
- size);
- return NULL;
+ return find_sec(hdr, sechdrs, secstrings, ".data..percpu");
}
-static void percpu_modfree(void *freeme)
+static void percpu_modcopy(struct module *mod,
+ const void *from, unsigned long size)
{
- unsigned int i;
- void *ptr = __per_cpu_start + block_size(pcpu_size[0]);
int cpu;
- /* First entry is core kernel percpu data. */
- for (i = 1; i < pcpu_num_used; ptr += block_size(pcpu_size[i]), i++) {
- if (ptr == freeme) {
- pcpu_size[i] = -pcpu_size[i];
- goto free;
- }
- }
- BUG();
-
- free:
- /* remove the per-cpu scanning areas */
for_each_possible_cpu(cpu)
- kmemleak_free(freeme + per_cpu_offset(cpu));
-
- /* Merge with previous? */
- if (pcpu_size[i-1] >= 0) {
- pcpu_size[i-1] += pcpu_size[i];
- pcpu_num_used--;
- memmove(&pcpu_size[i], &pcpu_size[i+1],
- (pcpu_num_used - i) * sizeof(pcpu_size[0]));
- i--;
- }
- /* Merge with next? */
- if (i+1 < pcpu_num_used && pcpu_size[i+1] >= 0) {
- pcpu_size[i] += pcpu_size[i+1];
- pcpu_num_used--;
- memmove(&pcpu_size[i+1], &pcpu_size[i+2],
- (pcpu_num_used - (i+1)) * sizeof(pcpu_size[0]));
- }
+ memcpy(per_cpu_ptr(mod->percpu, cpu), from, size);
}
-static int percpu_modinit(void)
+/**
+ * is_module_percpu_address - test whether address is from module static percpu
+ * @addr: address to test
+ *
+ * Test whether @addr belongs to module static percpu area.
+ *
+ * RETURNS:
+ * %true if @addr is from module static percpu area
+ */
+bool is_module_percpu_address(unsigned long addr)
{
- pcpu_num_used = 2;
- pcpu_num_allocated = 2;
- pcpu_size = kmalloc(sizeof(pcpu_size[0]) * pcpu_num_allocated,
- GFP_KERNEL);
- /* Static in-kernel percpu data (used). */
- pcpu_size[0] = -(__per_cpu_end-__per_cpu_start);
- /* Free room. */
- pcpu_size[1] = PERCPU_ENOUGH_ROOM + pcpu_size[0];
- if (pcpu_size[1] < 0) {
- printk(KERN_ERR "No per-cpu room for modules.\n");
- pcpu_num_used = 1;
- }
-
- return 0;
-}
-__initcall(percpu_modinit);
+ struct module *mod;
+ unsigned int cpu;
-#endif /* CONFIG_HAVE_DYNAMIC_PER_CPU_AREA */
+ preempt_disable();
-static unsigned int find_pcpusec(Elf_Ehdr *hdr,
- Elf_Shdr *sechdrs,
- const char *secstrings)
-{
- return find_sec(hdr, sechdrs, secstrings, ".data.percpu");
-}
+ list_for_each_entry_rcu(mod, &modules, list) {
+ if (!mod->percpu_size)
+ continue;
+ for_each_possible_cpu(cpu) {
+ void *start = per_cpu_ptr(mod->percpu, cpu);
-static void percpu_modcopy(void *pcpudest, const void *from, unsigned long size)
-{
- int cpu;
+ if ((void *)addr >= start &&
+ (void *)addr < start + mod->percpu_size) {
+ preempt_enable();
+ return true;
+ }
+ }
+ }
- for_each_possible_cpu(cpu)
- memcpy(pcpudest + per_cpu_offset(cpu), from, size);
+ preempt_enable();
+ return false;
}
#else /* ... !CONFIG_SMP */
-static inline void *percpu_modalloc(unsigned long size, unsigned long align,
- const char *name)
+static inline void __percpu *mod_percpu(struct module *mod)
{
return NULL;
}
-static inline void percpu_modfree(void *pcpuptr)
+static inline int percpu_modalloc(struct module *mod,
+ unsigned long size, unsigned long align)
+{
+ return -ENOMEM;
+}
+static inline void percpu_modfree(struct module *mod)
{
- BUG();
}
static inline unsigned int find_pcpusec(Elf_Ehdr *hdr,
Elf_Shdr *sechdrs,
{
return 0;
}
-static inline void percpu_modcopy(void *pcpudst, const void *src,
- unsigned long size)
+static inline void percpu_modcopy(struct module *mod,
+ const void *from, unsigned long size)
{
/* pcpusec should be 0, and size of that section should be 0. */
BUG_ON(size != 0);
}
+bool is_module_percpu_address(unsigned long addr)
+{
+ return false;
+}
#endif /* CONFIG_SMP */
static char last_unloaded_module[MODULE_NAME_LEN+1];
#ifdef CONFIG_MODULE_UNLOAD
+
+EXPORT_TRACEPOINT_SYMBOL(module_get);
+
/* Init the unload section of the module. */
static void module_unload_init(struct module *mod)
{
int cpu;
- INIT_LIST_HEAD(&mod->modules_which_use_me);
- for_each_possible_cpu(cpu)
- local_set(__module_ref_addr(mod, cpu), 0);
+ INIT_LIST_HEAD(&mod->source_list);
+ INIT_LIST_HEAD(&mod->target_list);
+ for_each_possible_cpu(cpu) {
+ per_cpu_ptr(mod->refptr, cpu)->incs = 0;
+ per_cpu_ptr(mod->refptr, cpu)->decs = 0;
+ }
+
/* Hold reference count during initialization. */
- local_set(__module_ref_addr(mod, raw_smp_processor_id()), 1);
+ __this_cpu_write(mod->refptr->incs, 1);
/* Backwards compatibility macros put refcount during init. */
mod->waiter = current;
}
-/* modules using other modules */
-struct module_use
-{
- struct list_head list;
- struct module *module_which_uses;
-};
-
/* Does a already use b? */
static int already_uses(struct module *a, struct module *b)
{
struct module_use *use;
- list_for_each_entry(use, &b->modules_which_use_me, list) {
- if (use->module_which_uses == a) {
+ list_for_each_entry(use, &b->source_list, source_list) {
+ if (use->source == a) {
DEBUGP("%s uses %s!\n", a->name, b->name);
return 1;
}
return 0;
}
-/* Module a uses b */
-int use_module(struct module *a, struct module *b)
+/*
+ * Module a uses b
+ * - we add 'a' as a "source", 'b' as a "target" of module use
+ * - the module_use is added to the list of 'b' sources (so
+ * 'b' can walk the list to see who sourced them), and of 'a'
+ * targets (so 'a' can see what modules it targets).
+ */
+static int add_module_usage(struct module *a, struct module *b)
{
struct module_use *use;
- int no_warn, err;
- if (b == NULL || already_uses(a, b)) return 1;
+ DEBUGP("Allocating new usage for %s.\n", a->name);
+ use = kmalloc(sizeof(*use), GFP_ATOMIC);
+ if (!use) {
+ printk(KERN_WARNING "%s: out of memory loading\n", a->name);
+ return -ENOMEM;
+ }
+
+ use->source = a;
+ use->target = b;
+ list_add(&use->source_list, &b->source_list);
+ list_add(&use->target_list, &a->target_list);
+ return 0;
+}
+
+/* Module a uses b: caller needs module_mutex() */
+int ref_module(struct module *a, struct module *b)
+{
+ int err;
- /* If we're interrupted or time out, we fail. */
- if (wait_event_interruptible_timeout(
- module_wq, (err = strong_try_module_get(b)) != -EBUSY,
- 30 * HZ) <= 0) {
- printk("%s: gave up waiting for init of module %s.\n",
- a->name, b->name);
+ if (b == NULL || already_uses(a, b))
return 0;
- }
- /* If strong_try_module_get() returned a different error, we fail. */
+ /* If module isn't available, we fail. */
+ err = strong_try_module_get(b);
if (err)
- return 0;
+ return err;
- DEBUGP("Allocating new usage for %s.\n", a->name);
- use = kmalloc(sizeof(*use), GFP_ATOMIC);
- if (!use) {
- printk("%s: out of memory loading\n", a->name);
+ err = add_module_usage(a, b);
+ if (err) {
module_put(b);
- return 0;
+ return err;
}
-
- use->module_which_uses = a;
- list_add(&use->list, &b->modules_which_use_me);
- no_warn = sysfs_create_link(b->holders_dir, &a->mkobj.kobj, a->name);
- return 1;
+ return 0;
}
-EXPORT_SYMBOL_GPL(use_module);
+EXPORT_SYMBOL_GPL(ref_module);
/* Clear the unload stuff of the module. */
static void module_unload_free(struct module *mod)
{
- struct module *i;
+ struct module_use *use, *tmp;
- list_for_each_entry(i, &modules, list) {
- struct module_use *use;
-
- list_for_each_entry(use, &i->modules_which_use_me, list) {
- if (use->module_which_uses == mod) {
- DEBUGP("%s unusing %s\n", mod->name, i->name);
- module_put(i);
- list_del(&use->list);
- kfree(use);
- sysfs_remove_link(i->holders_dir, mod->name);
- /* There can be at most one match. */
- break;
- }
- }
+ mutex_lock(&module_mutex);
+ list_for_each_entry_safe(use, tmp, &mod->target_list, target_list) {
+ struct module *i = use->target;
+ DEBUGP("%s unusing %s\n", mod->name, i->name);
+ module_put(i);
+ list_del(&use->source_list);
+ list_del(&use->target_list);
+ kfree(use);
}
+ mutex_unlock(&module_mutex);
}
#ifdef CONFIG_MODULE_FORCE_UNLOAD
unsigned int module_refcount(struct module *mod)
{
- unsigned int total = 0;
+ unsigned int incs = 0, decs = 0;
int cpu;
for_each_possible_cpu(cpu)
- total += local_read(__module_ref_addr(mod, cpu));
- return total;
+ decs += per_cpu_ptr(mod->refptr, cpu)->decs;
+ /*
+ * ensure the incs are added up after the decs.
+ * module_put ensures incs are visible before decs with smp_wmb.
+ *
+ * This 2-count scheme avoids the situation where the refcount
+ * for CPU0 is read, then CPU0 increments the module refcount,
+ * then CPU1 drops that refcount, then the refcount for CPU1 is
+ * read. We would record a decrement but not its corresponding
+ * increment so we would see a low count (disaster).
+ *
+ * Rare situation? But module_refcount can be preempted, and we
+ * might be tallying up 4096+ CPUs. So it is not impossible.
+ */
+ smp_rmb();
+ for_each_possible_cpu(cpu)
+ incs += per_cpu_ptr(mod->refptr, cpu)->incs;
+ return incs - decs;
}
EXPORT_SYMBOL(module_refcount);
return -EFAULT;
name[MODULE_NAME_LEN-1] = '\0';
- /* Create stop_machine threads since free_module relies on
- * a non-failing stop_machine call. */
- ret = stop_machine_create();
- if (ret)
- return ret;
-
- if (mutex_lock_interruptible(&module_mutex) != 0) {
- ret = -EINTR;
- goto out_stop;
- }
+ if (mutex_lock_interruptible(&module_mutex) != 0)
+ return -EINTR;
mod = find_module(name);
if (!mod) {
goto out;
}
- if (!list_empty(&mod->modules_which_use_me)) {
+ if (!list_empty(&mod->source_list)) {
/* Other modules depend on us: get rid of them first. */
ret = -EWOULDBLOCK;
goto out;
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
async_synchronize_full();
- mutex_lock(&module_mutex);
+
/* Store the name of the last unloaded module for diagnostic purposes */
strlcpy(last_unloaded_module, mod->name, sizeof(last_unloaded_module));
ddebug_remove_module(mod->name);
- free_module(mod);
- out:
+ free_module(mod);
+ return 0;
+out:
mutex_unlock(&module_mutex);
-out_stop:
- stop_machine_destroy();
return ret;
}
/* Always include a trailing , so userspace can differentiate
between this and the old multi-field proc format. */
- list_for_each_entry(use, &mod->modules_which_use_me, list) {
+ list_for_each_entry(use, &mod->source_list, source_list) {
printed_something = 1;
- seq_printf(m, "%s,", use->module_which_uses->name);
+ seq_printf(m, "%s,", use->source->name);
}
if (mod->init != NULL && mod->exit == NULL) {
}
EXPORT_SYMBOL(__symbol_put);
+/* Note this assumes addr is a function, which it currently always is. */
void symbol_put_addr(void *addr)
{
struct module *modaddr;
+ unsigned long a = (unsigned long)dereference_function_descriptor(addr);
- if (core_kernel_text((unsigned long)addr))
+ if (core_kernel_text(a))
return;
/* module_text_address is safe here: we're supposed to have reference
* to module from symbol_get, so it can't go away. */
- modaddr = __module_text_address((unsigned long)addr);
+ modaddr = __module_text_address(a);
BUG_ON(!modaddr);
module_put(modaddr);
}
void module_put(struct module *module)
{
if (module) {
- unsigned int cpu = get_cpu();
- local_dec(__module_ref_addr(module, cpu));
+ preempt_disable();
+ smp_wmb(); /* see comment in module_refcount */
+ __this_cpu_inc(module->refptr->decs);
+
+ trace_module_put(module, _RET_IP_);
/* Maybe they're waiting for us to drop reference? */
if (unlikely(!module_is_live(module)))
wake_up_process(module->waiter);
- put_cpu();
+ preempt_enable();
}
}
EXPORT_SYMBOL(module_put);
{
}
-int use_module(struct module *a, struct module *b)
+int ref_module(struct module *a, struct module *b)
{
- return strong_try_module_get(b) == 0;
+ return strong_try_module_get(b);
}
-EXPORT_SYMBOL_GPL(use_module);
+EXPORT_SYMBOL_GPL(ref_module);
static inline void module_unload_init(struct module *mod)
{
}
#ifdef CONFIG_MODVERSIONS
+/* If the arch applies (non-zero) relocations to kernel kcrctab, unapply it. */
+static unsigned long maybe_relocated(unsigned long crc,
+ const struct module *crc_owner)
+{
+#ifdef ARCH_RELOCATES_KCRCTAB
+ if (crc_owner == NULL)
+ return crc - (unsigned long)reloc_start;
+#endif
+ return crc;
+}
+
static int check_version(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *symname,
struct module *mod,
- const unsigned long *crc)
+ const unsigned long *crc,
+ const struct module *crc_owner)
{
unsigned int i, num_versions;
struct modversion_info *versions;
if (strcmp(versions[i].name, symname) != 0)
continue;
- if (versions[i].crc == *crc)
+ if (versions[i].crc == maybe_relocated(*crc, crc_owner))
return 1;
DEBUGP("Found checksum %lX vs module %lX\n",
- *crc, versions[i].crc);
+ maybe_relocated(*crc, crc_owner), versions[i].crc);
goto bad_version;
}
{
const unsigned long *crc;
- if (!find_symbol("module_layout", NULL, &crc, true, false))
+ /* Since this should be found in kernel (which can't be removed),
+ * no locking is necessary. */
+ if (!find_symbol(MODULE_SYMBOL_PREFIX "module_layout", NULL,
+ &crc, true, false))
BUG();
- return check_version(sechdrs, versindex, "module_layout", mod, crc);
+ return check_version(sechdrs, versindex, "module_layout", mod, crc,
+ NULL);
}
/* First part is kernel version, which we ignore if module has crcs. */
unsigned int versindex,
const char *symname,
struct module *mod,
- const unsigned long *crc)
+ const unsigned long *crc,
+ const struct module *crc_owner)
{
return 1;
}
}
#endif /* CONFIG_MODVERSIONS */
-/* Resolve a symbol for this module. I.e. if we find one, record usage.
- Must be holding module_mutex. */
+/* Resolve a symbol for this module. I.e. if we find one, record usage. */
static const struct kernel_symbol *resolve_symbol(Elf_Shdr *sechdrs,
unsigned int versindex,
const char *name,
- struct module *mod)
+ struct module *mod,
+ char ownername[])
{
struct module *owner;
const struct kernel_symbol *sym;
const unsigned long *crc;
+ int err;
+ mutex_lock(&module_mutex);
sym = find_symbol(name, &owner, &crc,
!(mod->taints & (1 << TAINT_PROPRIETARY_MODULE)), true);
- /* use_module can fail due to OOM,
- or module initialization or unloading */
- if (sym) {
- if (!check_version(sechdrs, versindex, name, mod, crc) ||
- !use_module(mod, owner))
- sym = NULL;
+ if (!sym)
+ goto unlock;
+
+ if (!check_version(sechdrs, versindex, name, mod, crc, owner)) {
+ sym = ERR_PTR(-EINVAL);
+ goto getname;
}
+
+ err = ref_module(mod, owner);
+ if (err) {
+ sym = ERR_PTR(err);
+ goto getname;
+ }
+
+getname:
+ /* We must make copy under the lock if we failed to get ref. */
+ strncpy(ownername, module_name(owner), MODULE_NAME_LEN);
+unlock:
+ mutex_unlock(&module_mutex);
return sym;
}
+static const struct kernel_symbol *resolve_symbol_wait(Elf_Shdr *sechdrs,
+ unsigned int versindex,
+ const char *name,
+ struct module *mod)
+{
+ const struct kernel_symbol *ksym;
+ char ownername[MODULE_NAME_LEN];
+
+ if (wait_event_interruptible_timeout(module_wq,
+ !IS_ERR(ksym = resolve_symbol(sechdrs, versindex, name,
+ mod, ownername)) ||
+ PTR_ERR(ksym) != -EBUSY,
+ 30 * HZ) <= 0) {
+ printk(KERN_WARNING "%s: gave up waiting for init of module %s.\n",
+ mod->name, ownername);
+ }
+ return ksym;
+}
+
/*
* /sys/module/foo/sections stuff
* J. Corbet <corbet@lwn.net>
*/
#if defined(CONFIG_KALLSYMS) && defined(CONFIG_SYSFS)
+
+static inline bool sect_empty(const Elf_Shdr *sect)
+{
+ return !(sect->sh_flags & SHF_ALLOC) || sect->sh_size == 0;
+}
+
struct module_sect_attr
{
struct module_attribute mattr;
/* Count loaded sections and allocate structures */
for (i = 0; i < nsect; i++)
- if (sechdrs[i].sh_flags & SHF_ALLOC)
+ if (!sect_empty(&sechdrs[i]))
nloaded++;
size[0] = ALIGN(sizeof(*sect_attrs)
+ nloaded * sizeof(sect_attrs->attrs[0]),
sattr = §_attrs->attrs[0];
gattr = §_attrs->grp.attrs[0];
for (i = 0; i < nsect; i++) {
- if (! (sechdrs[i].sh_flags & SHF_ALLOC))
+ if (sect_empty(&sechdrs[i]))
continue;
sattr->address = sechdrs[i].sh_addr;
sattr->name = kstrdup(secstrings + sechdrs[i].sh_name,
if (sattr->name == NULL)
goto out;
sect_attrs->nsections++;
+ sysfs_attr_init(&sattr->mattr.attr);
sattr->mattr.show = module_sect_show;
sattr->mattr.store = NULL;
sattr->mattr.attr.name = sattr->name;
struct bin_attribute attrs[0];
};
-static ssize_t module_notes_read(struct kobject *kobj,
+static ssize_t module_notes_read(struct file *filp, struct kobject *kobj,
struct bin_attribute *bin_attr,
char *buf, loff_t pos, size_t count)
{
struct module_notes_attrs *notes_attrs;
struct bin_attribute *nattr;
+ /* failed to create section attributes, so can't create notes */
+ if (!mod->sect_attrs)
+ return;
+
/* Count notes sections and allocate structures. */
notes = 0;
for (i = 0; i < nsect; i++)
- if ((sechdrs[i].sh_flags & SHF_ALLOC) &&
+ if (!sect_empty(&sechdrs[i]) &&
(sechdrs[i].sh_type == SHT_NOTE))
++notes;
notes_attrs->notes = notes;
nattr = ¬es_attrs->attrs[0];
for (loaded = i = 0; i < nsect; ++i) {
- if (!(sechdrs[i].sh_flags & SHF_ALLOC))
+ if (sect_empty(&sechdrs[i]))
continue;
if (sechdrs[i].sh_type == SHT_NOTE) {
+ sysfs_bin_attr_init(nattr);
nattr->attr.name = mod->sect_attrs->attrs[loaded].name;
nattr->attr.mode = S_IRUGO;
nattr->size = sechdrs[i].sh_size;
#endif
#ifdef CONFIG_SYSFS
-int module_add_modinfo_attrs(struct module *mod)
+static void add_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+ int nowarn;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list) {
+ nowarn = sysfs_create_link(use->target->holders_dir,
+ &mod->mkobj.kobj, mod->name);
+ }
+ mutex_unlock(&module_mutex);
+#endif
+}
+
+static void del_usage_links(struct module *mod)
+{
+#ifdef CONFIG_MODULE_UNLOAD
+ struct module_use *use;
+
+ mutex_lock(&module_mutex);
+ list_for_each_entry(use, &mod->target_list, target_list)
+ sysfs_remove_link(use->target->holders_dir, mod->name);
+ mutex_unlock(&module_mutex);
+#endif
+}
+
+static int module_add_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
struct module_attribute *temp_attr;
if (!attr->test ||
(attr->test && attr->test(mod))) {
memcpy(temp_attr, attr, sizeof(*temp_attr));
+ sysfs_attr_init(&temp_attr->attr);
error = sysfs_create_file(&mod->mkobj.kobj,&temp_attr->attr);
++temp_attr;
}
return error;
}
-void module_remove_modinfo_attrs(struct module *mod)
+static void module_remove_modinfo_attrs(struct module *mod)
{
struct module_attribute *attr;
int i;
kfree(mod->modinfo_attrs);
}
-int mod_sysfs_init(struct module *mod)
+static int mod_sysfs_init(struct module *mod)
{
int err;
struct kobject *kobj;
return err;
}
-int mod_sysfs_setup(struct module *mod,
+static int mod_sysfs_setup(struct module *mod,
struct kernel_param *kparam,
unsigned int num_params)
{
int err;
+ err = mod_sysfs_init(mod);
+ if (err)
+ goto out;
+
mod->holders_dir = kobject_create_and_add("holders", &mod->mkobj.kobj);
if (!mod->holders_dir) {
err = -ENOMEM;
if (err)
goto out_unreg_param;
+ add_usage_links(mod);
+
kobject_uevent(&mod->mkobj.kobj, KOBJ_ADD);
return 0;
kobject_put(mod->holders_dir);
out_unreg:
kobject_put(&mod->mkobj.kobj);
+out:
return err;
}
#else /* CONFIG_SYSFS */
+static inline int mod_sysfs_init(struct module *mod)
+{
+ return 0;
+}
+
+static inline int mod_sysfs_setup(struct module *mod,
+ struct kernel_param *kparam,
+ unsigned int num_params)
+{
+ return 0;
+}
+
+static inline int module_add_modinfo_attrs(struct module *mod)
+{
+ return 0;
+}
+
+static inline void module_remove_modinfo_attrs(struct module *mod)
+{
+}
+
static void mod_sysfs_fini(struct module *mod)
{
}
+static void del_usage_links(struct module *mod)
+{
+}
+
#endif /* CONFIG_SYSFS */
static void mod_kobject_remove(struct module *mod)
{
+ del_usage_links(mod);
module_remove_modinfo_attrs(mod);
module_param_sysfs_remove(mod);
kobject_put(mod->mkobj.drivers_dir);
return 0;
}
-/* Free a module, remove from lists, etc (must hold module_mutex). */
+/* Free a module, remove from lists, etc. */
static void free_module(struct module *mod)
{
+ trace_module_free(mod);
+
/* Delete from various lists */
+ mutex_lock(&module_mutex);
stop_machine(__unlink_module, mod, NULL);
+ mutex_unlock(&module_mutex);
remove_notes_attrs(mod);
remove_sect_attrs(mod);
mod_kobject_remove(mod);
/* This may be NULL, but that's OK */
module_free(mod, mod->module_init);
kfree(mod->args);
- if (mod->percpu)
- percpu_modfree(mod->percpu);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+ percpu_modfree(mod);
+#if defined(CONFIG_MODULE_UNLOAD)
if (mod->refptr)
- percpu_modfree(mod->refptr);
+ free_percpu(mod->refptr);
#endif
/* Free lock-classes: */
lockdep_free_key_range(mod->module_core, mod->core_size);
/* Finally, free the core (containing the module structure) */
module_free(mod, mod->module_core);
+
+#ifdef CONFIG_MPU
+ update_protections(current->mm);
+#endif
}
void *__symbol_get(const char *symbol)
/*
* Ensure that an exported symbol [global namespace] does not already exist
* in the kernel or in some other module's exported symbol table.
+ *
+ * You must hold the module_mutex.
*/
static int verify_export_symbols(struct module *mod)
{
break;
case SHN_UNDEF:
- ksym = resolve_symbol(sechdrs, versindex,
- strtab + sym[i].st_name, mod);
+ ksym = resolve_symbol_wait(sechdrs, versindex,
+ strtab + sym[i].st_name,
+ mod);
/* Ok if resolved. */
- if (ksym) {
+ if (ksym && !IS_ERR(ksym)) {
sym[i].st_value = ksym->value;
break;
}
/* Ok if weak. */
- if (ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
+ if (!ksym && ELF_ST_BIND(sym[i].st_info) == STB_WEAK)
break;
- printk(KERN_WARNING "%s: Unknown symbol %s\n",
- mod->name, strtab + sym[i].st_name);
- ret = -ENOENT;
+ printk(KERN_WARNING "%s: Unknown symbol %s (err %li)\n",
+ mod->name, strtab + sym[i].st_name,
+ PTR_ERR(ksym));
+ ret = PTR_ERR(ksym) ?: -ENOENT;
break;
default:
/* Divert to percpu allocation if a percpu var. */
if (sym[i].st_shndx == pcpuindex)
- secbase = (unsigned long)mod->percpu;
+ secbase = (unsigned long)mod_percpu(mod);
else
secbase = sechdrs[sym[i].st_shndx].sh_addr;
sym[i].st_value += secbase;
}
}
+static void free_modinfo(struct module *mod)
+{
+ struct module_attribute *attr;
+ int i;
+
+ for (i = 0; (attr = modinfo_attrs[i]); i++) {
+ if (attr->free)
+ attr->free(mod);
+ }
+}
+
#ifdef CONFIG_KALLSYMS
/* lookup symbol in given range of kernel_symbols */
return '?';
}
+static bool is_core_symbol(const Elf_Sym *src, const Elf_Shdr *sechdrs,
+ unsigned int shnum)
+{
+ const Elf_Shdr *sec;
+
+ if (src->st_shndx == SHN_UNDEF
+ || src->st_shndx >= shnum
+ || !src->st_name)
+ return false;
+
+ sec = sechdrs + src->st_shndx;
+ if (!(sec->sh_flags & SHF_ALLOC)
+#ifndef CONFIG_KALLSYMS_ALL
+ || !(sec->sh_flags & SHF_EXECINSTR)
+#endif
+ || (sec->sh_entsize & INIT_OFFSET_MASK))
+ return false;
+
+ return true;
+}
+
+static unsigned long layout_symtab(struct module *mod,
+ Elf_Shdr *sechdrs,
+ unsigned int symindex,
+ unsigned int strindex,
+ const Elf_Ehdr *hdr,
+ const char *secstrings,
+ unsigned long *pstroffs,
+ unsigned long *strmap)
+{
+ unsigned long symoffs;
+ Elf_Shdr *symsect = sechdrs + symindex;
+ Elf_Shdr *strsect = sechdrs + strindex;
+ const Elf_Sym *src;
+ const char *strtab;
+ unsigned int i, nsrc, ndst;
+
+ /* Put symbol section at end of init part of module. */
+ symsect->sh_flags |= SHF_ALLOC;
+ symsect->sh_entsize = get_offset(mod, &mod->init_size, symsect,
+ symindex) | INIT_OFFSET_MASK;
+ DEBUGP("\t%s\n", secstrings + symsect->sh_name);
+
+ src = (void *)hdr + symsect->sh_offset;
+ nsrc = symsect->sh_size / sizeof(*src);
+ strtab = (void *)hdr + strsect->sh_offset;
+ for (ndst = i = 1; i < nsrc; ++i, ++src)
+ if (is_core_symbol(src, sechdrs, hdr->e_shnum)) {
+ unsigned int j = src->st_name;
+
+ while(!__test_and_set_bit(j, strmap) && strtab[j])
+ ++j;
+ ++ndst;
+ }
+
+ /* Append room for core symbols at end of core part. */
+ symoffs = ALIGN(mod->core_size, symsect->sh_addralign ?: 1);
+ mod->core_size = symoffs + ndst * sizeof(Elf_Sym);
+
+ /* Put string table section at end of init part of module. */
+ strsect->sh_flags |= SHF_ALLOC;
+ strsect->sh_entsize = get_offset(mod, &mod->init_size, strsect,
+ strindex) | INIT_OFFSET_MASK;
+ DEBUGP("\t%s\n", secstrings + strsect->sh_name);
+
+ /* Append room for core symbols' strings at end of core part. */
+ *pstroffs = mod->core_size;
+ __set_bit(0, strmap);
+ mod->core_size += bitmap_weight(strmap, strsect->sh_size);
+
+ return symoffs;
+}
+
static void add_kallsyms(struct module *mod,
Elf_Shdr *sechdrs,
+ unsigned int shnum,
unsigned int symindex,
unsigned int strindex,
- const char *secstrings)
+ unsigned long symoffs,
+ unsigned long stroffs,
+ const char *secstrings,
+ unsigned long *strmap)
{
- unsigned int i;
+ unsigned int i, ndst;
+ const Elf_Sym *src;
+ Elf_Sym *dst;
+ char *s;
mod->symtab = (void *)sechdrs[symindex].sh_addr;
mod->num_symtab = sechdrs[symindex].sh_size / sizeof(Elf_Sym);
for (i = 0; i < mod->num_symtab; i++)
mod->symtab[i].st_info
= elf_type(&mod->symtab[i], sechdrs, secstrings, mod);
+
+ mod->core_symtab = dst = mod->module_core + symoffs;
+ src = mod->symtab;
+ *dst = *src;
+ for (ndst = i = 1; i < mod->num_symtab; ++i, ++src) {
+ if (!is_core_symbol(src, sechdrs, shnum))
+ continue;
+ dst[ndst] = *src;
+ dst[ndst].st_name = bitmap_weight(strmap, dst[ndst].st_name);
+ ++ndst;
+ }
+ mod->core_num_syms = ndst;
+
+ mod->core_strtab = s = mod->module_core + stroffs;
+ for (*s = 0, i = 1; i < sechdrs[strindex].sh_size; ++i)
+ if (test_bit(i, strmap))
+ *++s = mod->strtab[i];
}
#else
+static inline unsigned long layout_symtab(struct module *mod,
+ Elf_Shdr *sechdrs,
+ unsigned int symindex,
+ unsigned int strindex,
+ const Elf_Ehdr *hdr,
+ const char *secstrings,
+ unsigned long *pstroffs,
+ unsigned long *strmap)
+{
+ return 0;
+}
+
static inline void add_kallsyms(struct module *mod,
Elf_Shdr *sechdrs,
+ unsigned int shnum,
unsigned int symindex,
unsigned int strindex,
- const char *secstrings)
+ unsigned long symoffs,
+ unsigned long stroffs,
+ const char *secstrings,
+ const unsigned long *strmap)
{
}
#endif /* CONFIG_KALLSYMS */
void *ret = module_alloc(size);
if (ret) {
+ mutex_lock(&module_mutex);
/* Update module bounds. */
if ((unsigned long)ret < module_addr_min)
module_addr_min = (unsigned long)ret;
if ((unsigned long)ret + size > module_addr_max)
module_addr_max = (unsigned long)ret + size;
+ mutex_unlock(&module_mutex);
}
return ret;
}
unsigned int i;
/* only scan the sections containing data */
- kmemleak_scan_area(mod->module_core, (unsigned long)mod -
- (unsigned long)mod->module_core,
- sizeof(struct module), GFP_KERNEL);
+ kmemleak_scan_area(mod, sizeof(struct module), GFP_KERNEL);
for (i = 1; i < hdr->e_shnum; i++) {
if (!(sechdrs[i].sh_flags & SHF_ALLOC))
&& strncmp(secstrings + sechdrs[i].sh_name, ".bss", 4) != 0)
continue;
- kmemleak_scan_area(mod->module_core, sechdrs[i].sh_addr -
- (unsigned long)mod->module_core,
+ kmemleak_scan_area((void *)sechdrs[i].sh_addr,
sechdrs[i].sh_size, GFP_KERNEL);
}
}
unsigned int modindex, versindex, infoindex, pcpuindex;
struct module *mod;
long err = 0;
- void *percpu = NULL, *ptr = NULL; /* Stops spurious gcc warning */
+ void *ptr = NULL; /* Stops spurious gcc warning */
+ unsigned long symoffs, stroffs, *strmap;
+ void __percpu *percpu;
+
mm_segment_t old_fs;
DEBUGP("load_module: umod=%p, len=%lu, uargs=%p\n",
/* Don't keep modinfo and version sections. */
sechdrs[infoindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
sechdrs[versindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
-#ifdef CONFIG_KALLSYMS
- /* Keep symbol and string tables for decoding later. */
- sechdrs[symindex].sh_flags |= SHF_ALLOC;
- sechdrs[strindex].sh_flags |= SHF_ALLOC;
-#endif
/* Check module struct version now, before we try to use module. */
if (!check_modstruct_version(sechdrs, versindex, mod)) {
goto free_hdr;
}
- if (find_module(mod->name)) {
- err = -EEXIST;
+ strmap = kzalloc(BITS_TO_LONGS(sechdrs[strindex].sh_size)
+ * sizeof(long), GFP_KERNEL);
+ if (!strmap) {
+ err = -ENOMEM;
goto free_mod;
}
if (pcpuindex) {
/* We have a special allocation for this section. */
- percpu = percpu_modalloc(sechdrs[pcpuindex].sh_size,
- sechdrs[pcpuindex].sh_addralign,
- mod->name);
- if (!percpu) {
- err = -ENOMEM;
+ err = percpu_modalloc(mod, sechdrs[pcpuindex].sh_size,
+ sechdrs[pcpuindex].sh_addralign);
+ if (err)
goto free_mod;
- }
sechdrs[pcpuindex].sh_flags &= ~(unsigned long)SHF_ALLOC;
- mod->percpu = percpu;
}
+ /* Keep this around for failure path. */
+ percpu = mod_percpu(mod);
/* Determine total sizes, and put offsets in sh_entsize. For now
this is done generically; there doesn't appear to be any
special cases for the architectures. */
layout_sections(mod, hdr, sechdrs, secstrings);
+ symoffs = layout_symtab(mod, sechdrs, symindex, strindex, hdr,
+ secstrings, &stroffs, strmap);
/* Do the allocs. */
ptr = module_alloc_update_bounds(mod->core_size);
mod = (void *)sechdrs[modindex].sh_addr;
kmemleak_load_module(mod, hdr, sechdrs, secstrings);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
- mod->refptr = percpu_modalloc(sizeof(local_t), __alignof__(local_t),
- mod->name);
+#if defined(CONFIG_MODULE_UNLOAD)
+ mod->refptr = alloc_percpu(struct module_ref);
if (!mod->refptr) {
err = -ENOMEM;
goto free_init;
/* Now we've moved module, initialize linked lists, etc. */
module_unload_init(mod);
- /* add kobject, so we can reference it. */
- err = mod_sysfs_init(mod);
- if (err)
- goto free_unload;
-
/* Set up license info based on the info section */
set_license(mod, get_modinfo(sechdrs, infoindex, "license"));
sizeof(*mod->ctors), &mod->num_ctors);
#endif
-#ifdef CONFIG_MARKERS
- mod->markers = section_objs(hdr, sechdrs, secstrings, "__markers",
- sizeof(*mod->markers), &mod->num_markers);
-#endif
#ifdef CONFIG_TRACEPOINTS
mod->tracepoints = section_objs(hdr, sechdrs, secstrings,
"__tracepoints",
"_ftrace_events",
sizeof(*mod->trace_events),
&mod->num_trace_events);
+ /*
+ * This section contains pointers to allocated objects in the trace
+ * code and not scanning it leads to false positives.
+ */
+ kmemleak_scan_area(mod->trace_events, sizeof(*mod->trace_events) *
+ mod->num_trace_events, GFP_KERNEL);
#endif
#ifdef CONFIG_FTRACE_MCOUNT_RECORD
/* sechdrs[0].sh_size is always zero */
goto cleanup;
}
- /* Find duplicate symbols */
- err = verify_export_symbols(mod);
- if (err < 0)
- goto cleanup;
-
/* Set up and sort exception table */
mod->extable = section_objs(hdr, sechdrs, secstrings, "__ex_table",
sizeof(*mod->extable), &mod->num_exentries);
sort_extable(mod->extable, mod->extable + mod->num_exentries);
/* Finally, copy percpu area over. */
- percpu_modcopy(mod->percpu, (void *)sechdrs[pcpuindex].sh_addr,
+ percpu_modcopy(mod, (void *)sechdrs[pcpuindex].sh_addr,
sechdrs[pcpuindex].sh_size);
- add_kallsyms(mod, sechdrs, symindex, strindex, secstrings);
+ add_kallsyms(mod, sechdrs, hdr->e_shnum, symindex, strindex,
+ symoffs, stroffs, secstrings, strmap);
+ kfree(strmap);
+ strmap = NULL;
if (!mod->taints) {
struct _ddebug *debug;
* function to insert in a way safe to concurrent readers.
* The mutex protects against concurrent writers.
*/
+ mutex_lock(&module_mutex);
+ if (find_module(mod->name)) {
+ err = -EEXIST;
+ goto unlock;
+ }
+
+ /* Find duplicate symbols */
+ err = verify_export_symbols(mod);
+ if (err < 0)
+ goto unlock;
+
list_add_rcu(&mod->list, &modules);
+ mutex_unlock(&module_mutex);
err = parse_args(mod->name, mod->args, mod->kp, mod->num_kp, NULL);
if (err < 0)
err = mod_sysfs_setup(mod, mod->kp, mod->num_kp);
if (err < 0)
goto unlink;
+
add_sect_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
add_notes_attrs(mod, hdr->e_shnum, secstrings, sechdrs);
/* Get rid of temporary copy */
vfree(hdr);
+ trace_module_load(mod);
+
/* Done! */
return mod;
unlink:
+ mutex_lock(&module_mutex);
/* Unlink carefully: kallsyms could be walking list. */
list_del_rcu(&mod->list);
+ unlock:
+ mutex_unlock(&module_mutex);
synchronize_sched();
module_arch_cleanup(mod);
cleanup:
- kobject_del(&mod->mkobj.kobj);
- kobject_put(&mod->mkobj.kobj);
- free_unload:
+ free_modinfo(mod);
module_unload_free(mod);
-#if defined(CONFIG_MODULE_UNLOAD) && defined(CONFIG_SMP)
+#if defined(CONFIG_MODULE_UNLOAD)
+ free_percpu(mod->refptr);
free_init:
- percpu_modfree(mod->refptr);
#endif
module_free(mod, mod->module_init);
free_core:
module_free(mod, mod->module_core);
/* mod will be freed with core. Don't access it beyond this line! */
free_percpu:
- if (percpu)
- percpu_modfree(percpu);
+ free_percpu(percpu);
free_mod:
kfree(args);
+ kfree(strmap);
free_hdr:
vfree(hdr);
return ERR_PTR(err);
if (!capable(CAP_SYS_MODULE) || modules_disabled)
return -EPERM;
- /* Only one module load at a time, please */
- if (mutex_lock_interruptible(&module_mutex) != 0)
- return -EINTR;
-
/* Do all the hard work */
mod = load_module(umod, len, uargs);
- if (IS_ERR(mod)) {
- mutex_unlock(&module_mutex);
+ if (IS_ERR(mod))
return PTR_ERR(mod);
- }
-
- /* Drop lock so they can recurse */
- mutex_unlock(&module_mutex);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_COMING, mod);
module_put(mod);
blocking_notifier_call_chain(&module_notify_list,
MODULE_STATE_GOING, mod);
- mutex_lock(&module_mutex);
free_module(mod);
- mutex_unlock(&module_mutex);
wake_up(&module_wq);
return ret;
}
if (ret > 0) {
- printk(KERN_WARNING "%s: '%s'->init suspiciously returned %d, "
- "it should follow 0/-E convention\n"
- KERN_WARNING "%s: loading module anyway...\n",
+ printk(KERN_WARNING
+"%s: '%s'->init suspiciously returned %d, it should follow 0/-E convention\n"
+"%s: loading module anyway...\n",
__func__, mod->name, ret,
__func__);
dump_stack();
/* Drop initial reference. */
module_put(mod);
trim_init_extable(mod);
+#ifdef CONFIG_KALLSYMS
+ mod->num_symtab = mod->core_num_syms;
+ mod->symtab = mod->core_symtab;
+ mod->strtab = mod->core_strtab;
+#endif
module_free(mod, mod->module_init);
mod->module_init = NULL;
mod->init_size = 0;
struct modversion_info *ver,
struct kernel_param *kp,
struct kernel_symbol *ks,
- struct marker *marker,
struct tracepoint *tp)
{
}
EXPORT_SYMBOL(module_layout);
#endif
-#ifdef CONFIG_MARKERS
-void module_update_markers(void)
-{
- struct module *mod;
-
- mutex_lock(&module_mutex);
- list_for_each_entry(mod, &modules, list)
- if (!mod->taints)
- marker_update_probe_range(mod->markers,
- mod->markers + mod->num_markers);
- mutex_unlock(&module_mutex);
-}
-#endif
-
#ifdef CONFIG_TRACEPOINTS
void module_update_tracepoints(void)
{