addr = ((kprobe_opcode_t *)(kallsyms_lookup_name(name)))
#endif
+static int kprobes_initialized;
static struct hlist_head kprobe_table[KPROBE_TABLE_SIZE];
static struct hlist_head kretprobe_inst_table[KPROBE_TABLE_SIZE];
static bool kprobe_enabled;
DEFINE_MUTEX(kprobe_mutex); /* Protects kprobe_table */
-DEFINE_SPINLOCK(kretprobe_lock); /* Protects kretprobe_inst_table */
static DEFINE_PER_CPU(struct kprobe *, kprobe_instance) = NULL;
+static struct {
+ spinlock_t lock ____cacheline_aligned;
+} kretprobe_table_locks[KPROBE_TABLE_SIZE];
+
+static spinlock_t *kretprobe_table_lock_ptr(unsigned long hash)
+{
+ return &(kretprobe_table_locks[hash].lock);
+}
+
+/*
+ * Normally, functions that we'd want to prohibit kprobes in, are marked
+ * __kprobes. But, there are cases where such functions already belong to
+ * a different section (__sched for preempt_schedule)
+ *
+ * For such cases, we now have a blacklist
+ */
+static struct kprobe_blackpoint kprobe_blacklist[] = {
+ {"preempt_schedule",},
+ {NULL} /* Terminator */
+};
#ifdef __ARCH_WANT_KPROBES_INSN_SLOT
/*
return;
}
-/* Called with kretprobe_lock held */
void __kprobes recycle_rp_inst(struct kretprobe_instance *ri,
struct hlist_head *head)
{
+ struct kretprobe *rp = ri->rp;
+
/* remove rp inst off the rprobe_inst_table */
hlist_del(&ri->hlist);
- if (ri->rp) {
- /* remove rp inst off the used list */
- hlist_del(&ri->uflist);
- /* put rp inst back onto the free list */
- INIT_HLIST_NODE(&ri->uflist);
- hlist_add_head(&ri->uflist, &ri->rp->free_instances);
+ INIT_HLIST_NODE(&ri->hlist);
+ if (likely(rp)) {
+ spin_lock(&rp->lock);
+ hlist_add_head(&ri->hlist, &rp->free_instances);
+ spin_unlock(&rp->lock);
} else
/* Unregistering */
hlist_add_head(&ri->hlist, head);
}
-struct hlist_head __kprobes *kretprobe_inst_table_head(struct task_struct *tsk)
+void kretprobe_hash_lock(struct task_struct *tsk,
+ struct hlist_head **head, unsigned long *flags)
+{
+ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
+ spinlock_t *hlist_lock;
+
+ *head = &kretprobe_inst_table[hash];
+ hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_lock_irqsave(hlist_lock, *flags);
+}
+
+void kretprobe_table_lock(unsigned long hash, unsigned long *flags)
+{
+ spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_lock_irqsave(hlist_lock, *flags);
+}
+
+void kretprobe_hash_unlock(struct task_struct *tsk, unsigned long *flags)
{
- return &kretprobe_inst_table[hash_ptr(tsk, KPROBE_HASH_BITS)];
+ unsigned long hash = hash_ptr(tsk, KPROBE_HASH_BITS);
+ spinlock_t *hlist_lock;
+
+ hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_unlock_irqrestore(hlist_lock, *flags);
+}
+
+void kretprobe_table_unlock(unsigned long hash, unsigned long *flags)
+{
+ spinlock_t *hlist_lock = kretprobe_table_lock_ptr(hash);
+ spin_unlock_irqrestore(hlist_lock, *flags);
}
/*
struct kretprobe_instance *ri;
struct hlist_head *head, empty_rp;
struct hlist_node *node, *tmp;
- unsigned long flags = 0;
+ unsigned long hash, flags = 0;
- INIT_HLIST_HEAD(&empty_rp);
- spin_lock_irqsave(&kretprobe_lock, flags);
- head = kretprobe_inst_table_head(tk);
+ if (unlikely(!kprobes_initialized))
+ /* Early boot. kretprobe_table_locks not yet initialized. */
+ return;
+
+ hash = hash_ptr(tk, KPROBE_HASH_BITS);
+ head = &kretprobe_inst_table[hash];
+ kretprobe_table_lock(hash, &flags);
hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
if (ri->task == tk)
recycle_rp_inst(ri, &empty_rp);
}
- spin_unlock_irqrestore(&kretprobe_lock, flags);
-
+ kretprobe_table_unlock(hash, &flags);
+ INIT_HLIST_HEAD(&empty_rp);
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
hlist_del(&ri->hlist);
kfree(ri);
struct kretprobe_instance *ri;
struct hlist_node *pos, *next;
- hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, uflist) {
- hlist_del(&ri->uflist);
+ hlist_for_each_entry_safe(ri, pos, next, &rp->free_instances, hlist) {
+ hlist_del(&ri->hlist);
kfree(ri);
}
}
+static void __kprobes cleanup_rp_inst(struct kretprobe *rp)
+{
+ unsigned long flags, hash;
+ struct kretprobe_instance *ri;
+ struct hlist_node *pos, *next;
+ struct hlist_head *head;
+
+ /* No race here */
+ for (hash = 0; hash < KPROBE_TABLE_SIZE; hash++) {
+ kretprobe_table_lock(hash, &flags);
+ head = &kretprobe_inst_table[hash];
+ hlist_for_each_entry_safe(ri, pos, next, head, hlist) {
+ if (ri->rp == rp)
+ ri->rp = NULL;
+ }
+ kretprobe_table_unlock(hash, &flags);
+ }
+ free_rp_inst(rp);
+}
+
/*
* Keep all fields in the kprobe consistent
*/
static int __kprobes in_kprobes_functions(unsigned long addr)
{
+ struct kprobe_blackpoint *kb;
+
if (addr >= (unsigned long)__kprobes_text_start &&
addr < (unsigned long)__kprobes_text_end)
return -EINVAL;
+ /*
+ * If there exists a kprobe_blacklist, verify and
+ * fail any probe registration in the prohibited area
+ */
+ for (kb = kprobe_blacklist; kb->name != NULL; kb++) {
+ if (kb->start_addr) {
+ if (addr >= kb->start_addr &&
+ addr < (kb->start_addr + kb->range))
+ return -EINVAL;
+ }
+ }
return 0;
}
+/*
+ * If we have a symbol_name argument, look it up and add the offset field
+ * to it. This way, we can specify a relative address to a symbol.
+ */
+static kprobe_opcode_t __kprobes *kprobe_addr(struct kprobe *p)
+{
+ kprobe_opcode_t *addr = p->addr;
+ if (p->symbol_name) {
+ if (addr)
+ return NULL;
+ kprobe_lookup_name(p->symbol_name, addr);
+ }
+
+ if (!addr)
+ return NULL;
+ return (kprobe_opcode_t *)(((char *)addr) + p->offset);
+}
+
static int __kprobes __register_kprobe(struct kprobe *p,
unsigned long called_from)
{
int ret = 0;
struct kprobe *old_p;
struct module *probed_mod;
+ kprobe_opcode_t *addr;
- /*
- * If we have a symbol_name argument look it up,
- * and add it to the address. That way the addr
- * field can either be global or relative to a symbol.
- */
- if (p->symbol_name) {
- if (p->addr)
- return -EINVAL;
- kprobe_lookup_name(p->symbol_name, p->addr);
- }
-
- if (!p->addr)
+ addr = kprobe_addr(p);
+ if (!addr)
return -EINVAL;
- p->addr = (kprobe_opcode_t *)(((char *)p->addr)+ p->offset);
+ p->addr = addr;
if (!kernel_text_address((unsigned long) p->addr) ||
in_kprobes_functions((unsigned long) p->addr))
}
p->nmissed = 0;
+ INIT_LIST_HEAD(&p->list);
mutex_lock(&kprobe_mutex);
old_p = get_kprobe(p->addr);
if (old_p) {
return ret;
}
-int __kprobes register_kprobe(struct kprobe *p)
-{
- return __register_kprobe(p, (unsigned long)__builtin_return_address(0));
-}
-
-void __kprobes unregister_kprobe(struct kprobe *p)
+/*
+ * Unregister a kprobe without a scheduler synchronization.
+ */
+static int __kprobes __unregister_kprobe_top(struct kprobe *p)
{
- struct module *mod;
struct kprobe *old_p, *list_p;
- int cleanup_p;
- mutex_lock(&kprobe_mutex);
old_p = get_kprobe(p->addr);
- if (unlikely(!old_p)) {
- mutex_unlock(&kprobe_mutex);
- return;
- }
+ if (unlikely(!old_p))
+ return -EINVAL;
+
if (p != old_p) {
list_for_each_entry_rcu(list_p, &old_p->list, list)
if (list_p == p)
/* kprobe p is a valid probe */
goto valid_p;
- mutex_unlock(&kprobe_mutex);
- return;
+ return -EINVAL;
}
valid_p:
if (old_p == p ||
(old_p->pre_handler == aggr_pre_handler &&
- p->list.next == &old_p->list && p->list.prev == &old_p->list)) {
+ list_is_singular(&old_p->list))) {
/*
* Only probe on the hash list. Disarm only if kprobes are
* enabled - otherwise, the breakpoint would already have
if (kprobe_enabled)
arch_disarm_kprobe(p);
hlist_del_rcu(&old_p->hlist);
- cleanup_p = 1;
} else {
+ if (p->break_handler)
+ old_p->break_handler = NULL;
+ if (p->post_handler) {
+ list_for_each_entry_rcu(list_p, &old_p->list, list) {
+ if ((list_p != p) && (list_p->post_handler))
+ goto noclean;
+ }
+ old_p->post_handler = NULL;
+ }
+noclean:
list_del_rcu(&p->list);
- cleanup_p = 0;
}
+ return 0;
+}
- mutex_unlock(&kprobe_mutex);
+static void __kprobes __unregister_kprobe_bottom(struct kprobe *p)
+{
+ struct module *mod;
+ struct kprobe *old_p;
- synchronize_sched();
if (p->mod_refcounted) {
mod = module_text_address((unsigned long)p->addr);
if (mod)
module_put(mod);
}
- if (cleanup_p) {
- if (p != old_p) {
- list_del_rcu(&p->list);
+ if (list_empty(&p->list) || list_is_singular(&p->list)) {
+ if (!list_empty(&p->list)) {
+ /* "p" is the last child of an aggr_kprobe */
+ old_p = list_entry(p->list.next, struct kprobe, list);
+ list_del(&p->list);
kfree(old_p);
}
arch_remove_kprobe(p);
- } else {
- mutex_lock(&kprobe_mutex);
- if (p->break_handler)
- old_p->break_handler = NULL;
- if (p->post_handler){
- list_for_each_entry_rcu(list_p, &old_p->list, list){
- if (list_p->post_handler){
- cleanup_p = 2;
- break;
- }
- }
- if (cleanup_p == 0)
- old_p->post_handler = NULL;
+ }
+}
+
+static int __register_kprobes(struct kprobe **kps, int num,
+ unsigned long called_from)
+{
+ int i, ret = 0;
+
+ if (num <= 0)
+ return -EINVAL;
+ for (i = 0; i < num; i++) {
+ ret = __register_kprobe(kps[i], called_from);
+ if (ret < 0) {
+ if (i > 0)
+ unregister_kprobes(kps, i);
+ break;
}
- mutex_unlock(&kprobe_mutex);
}
+ return ret;
+}
+
+/*
+ * Registration and unregistration functions for kprobe.
+ */
+int __kprobes register_kprobe(struct kprobe *p)
+{
+ return __register_kprobes(&p, 1,
+ (unsigned long)__builtin_return_address(0));
+}
+
+void __kprobes unregister_kprobe(struct kprobe *p)
+{
+ unregister_kprobes(&p, 1);
+}
+
+int __kprobes register_kprobes(struct kprobe **kps, int num)
+{
+ return __register_kprobes(kps, num,
+ (unsigned long)__builtin_return_address(0));
+}
+
+void __kprobes unregister_kprobes(struct kprobe **kps, int num)
+{
+ int i;
+
+ if (num <= 0)
+ return;
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < num; i++)
+ if (__unregister_kprobe_top(kps[i]) < 0)
+ kps[i]->addr = NULL;
+ mutex_unlock(&kprobe_mutex);
+
+ synchronize_sched();
+ for (i = 0; i < num; i++)
+ if (kps[i]->addr)
+ __unregister_kprobe_bottom(kps[i]);
}
static struct notifier_block kprobe_exceptions_nb = {
return (unsigned long)entry;
}
-int __kprobes register_jprobe(struct jprobe *jp)
+static int __register_jprobes(struct jprobe **jps, int num,
+ unsigned long called_from)
{
- unsigned long addr = arch_deref_entry_point(jp->entry);
+ struct jprobe *jp;
+ int ret = 0, i;
- if (!kernel_text_address(addr))
+ if (num <= 0)
return -EINVAL;
+ for (i = 0; i < num; i++) {
+ unsigned long addr;
+ jp = jps[i];
+ addr = arch_deref_entry_point(jp->entry);
+
+ if (!kernel_text_address(addr))
+ ret = -EINVAL;
+ else {
+ /* Todo: Verify probepoint is a function entry point */
+ jp->kp.pre_handler = setjmp_pre_handler;
+ jp->kp.break_handler = longjmp_break_handler;
+ ret = __register_kprobe(&jp->kp, called_from);
+ }
+ if (ret < 0) {
+ if (i > 0)
+ unregister_jprobes(jps, i);
+ break;
+ }
+ }
+ return ret;
+}
- /* Todo: Verify probepoint is a function entry point */
- jp->kp.pre_handler = setjmp_pre_handler;
- jp->kp.break_handler = longjmp_break_handler;
-
- return __register_kprobe(&jp->kp,
+int __kprobes register_jprobe(struct jprobe *jp)
+{
+ return __register_jprobes(&jp, 1,
(unsigned long)__builtin_return_address(0));
}
void __kprobes unregister_jprobe(struct jprobe *jp)
{
- unregister_kprobe(&jp->kp);
+ unregister_jprobes(&jp, 1);
+}
+
+int __kprobes register_jprobes(struct jprobe **jps, int num)
+{
+ return __register_jprobes(jps, num,
+ (unsigned long)__builtin_return_address(0));
+}
+
+void __kprobes unregister_jprobes(struct jprobe **jps, int num)
+{
+ int i;
+
+ if (num <= 0)
+ return;
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < num; i++)
+ if (__unregister_kprobe_top(&jps[i]->kp) < 0)
+ jps[i]->kp.addr = NULL;
+ mutex_unlock(&kprobe_mutex);
+
+ synchronize_sched();
+ for (i = 0; i < num; i++) {
+ if (jps[i]->kp.addr)
+ __unregister_kprobe_bottom(&jps[i]->kp);
+ }
}
#ifdef CONFIG_KRETPROBES
struct pt_regs *regs)
{
struct kretprobe *rp = container_of(p, struct kretprobe, kp);
- unsigned long flags = 0;
+ unsigned long hash, flags = 0;
+ struct kretprobe_instance *ri;
/*TODO: consider to only swap the RA after the last pre_handler fired */
- spin_lock_irqsave(&kretprobe_lock, flags);
+ hash = hash_ptr(current, KPROBE_HASH_BITS);
+ spin_lock_irqsave(&rp->lock, flags);
if (!hlist_empty(&rp->free_instances)) {
- struct kretprobe_instance *ri;
-
ri = hlist_entry(rp->free_instances.first,
- struct kretprobe_instance, uflist);
+ struct kretprobe_instance, hlist);
+ hlist_del(&ri->hlist);
+ spin_unlock_irqrestore(&rp->lock, flags);
+
ri->rp = rp;
ri->task = current;
if (rp->entry_handler && rp->entry_handler(ri, regs)) {
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ spin_unlock_irqrestore(&rp->lock, flags);
return 0;
}
arch_prepare_kretprobe(ri, regs);
/* XXX(hch): why is there no hlist_move_head? */
- hlist_del(&ri->uflist);
- hlist_add_head(&ri->uflist, &ri->rp->used_instances);
- hlist_add_head(&ri->hlist, kretprobe_inst_table_head(ri->task));
- } else
+ INIT_HLIST_NODE(&ri->hlist);
+ kretprobe_table_lock(hash, &flags);
+ hlist_add_head(&ri->hlist, &kretprobe_inst_table[hash]);
+ kretprobe_table_unlock(hash, &flags);
+ } else {
rp->nmissed++;
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ spin_unlock_irqrestore(&rp->lock, flags);
+ }
return 0;
}
-int __kprobes register_kretprobe(struct kretprobe *rp)
+static int __kprobes __register_kretprobe(struct kretprobe *rp,
+ unsigned long called_from)
{
int ret = 0;
struct kretprobe_instance *inst;
int i;
- void *addr = rp->kp.addr;
+ void *addr;
if (kretprobe_blacklist_size) {
- if (addr == NULL)
- kprobe_lookup_name(rp->kp.symbol_name, addr);
- addr += rp->kp.offset;
+ addr = kprobe_addr(&rp->kp);
+ if (!addr)
+ return -EINVAL;
for (i = 0; kretprobe_blacklist[i].name != NULL; i++) {
if (kretprobe_blacklist[i].addr == addr)
rp->maxactive = NR_CPUS;
#endif
}
- INIT_HLIST_HEAD(&rp->used_instances);
+ spin_lock_init(&rp->lock);
INIT_HLIST_HEAD(&rp->free_instances);
for (i = 0; i < rp->maxactive; i++) {
inst = kmalloc(sizeof(struct kretprobe_instance) +
free_rp_inst(rp);
return -ENOMEM;
}
- INIT_HLIST_NODE(&inst->uflist);
- hlist_add_head(&inst->uflist, &rp->free_instances);
+ INIT_HLIST_NODE(&inst->hlist);
+ hlist_add_head(&inst->hlist, &rp->free_instances);
}
rp->nmissed = 0;
/* Establish function entry probe point */
- if ((ret = __register_kprobe(&rp->kp,
- (unsigned long)__builtin_return_address(0))) != 0)
+ ret = __register_kprobe(&rp->kp, called_from);
+ if (ret != 0)
free_rp_inst(rp);
return ret;
}
+static int __register_kretprobes(struct kretprobe **rps, int num,
+ unsigned long called_from)
+{
+ int ret = 0, i;
+
+ if (num <= 0)
+ return -EINVAL;
+ for (i = 0; i < num; i++) {
+ ret = __register_kretprobe(rps[i], called_from);
+ if (ret < 0) {
+ if (i > 0)
+ unregister_kretprobes(rps, i);
+ break;
+ }
+ }
+ return ret;
+}
+
+int __kprobes register_kretprobe(struct kretprobe *rp)
+{
+ return __register_kretprobes(&rp, 1,
+ (unsigned long)__builtin_return_address(0));
+}
+
+void __kprobes unregister_kretprobe(struct kretprobe *rp)
+{
+ unregister_kretprobes(&rp, 1);
+}
+
+int __kprobes register_kretprobes(struct kretprobe **rps, int num)
+{
+ return __register_kretprobes(rps, num,
+ (unsigned long)__builtin_return_address(0));
+}
+
+void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
+{
+ int i;
+
+ if (num <= 0)
+ return;
+ mutex_lock(&kprobe_mutex);
+ for (i = 0; i < num; i++)
+ if (__unregister_kprobe_top(&rps[i]->kp) < 0)
+ rps[i]->kp.addr = NULL;
+ mutex_unlock(&kprobe_mutex);
+
+ synchronize_sched();
+ for (i = 0; i < num; i++) {
+ if (rps[i]->kp.addr) {
+ __unregister_kprobe_bottom(&rps[i]->kp);
+ cleanup_rp_inst(rps[i]);
+ }
+ }
+}
+
#else /* CONFIG_KRETPROBES */
int __kprobes register_kretprobe(struct kretprobe *rp)
{
return -ENOSYS;
}
-static int __kprobes pre_handler_kretprobe(struct kprobe *p,
- struct pt_regs *regs)
+int __kprobes register_kretprobes(struct kretprobe **rps, int num)
{
- return 0;
+ return -ENOSYS;
}
-#endif /* CONFIG_KRETPROBES */
-
void __kprobes unregister_kretprobe(struct kretprobe *rp)
{
- unsigned long flags;
- struct kretprobe_instance *ri;
- struct hlist_node *pos, *next;
+}
- unregister_kprobe(&rp->kp);
+void __kprobes unregister_kretprobes(struct kretprobe **rps, int num)
+{
+}
- /* No race here */
- spin_lock_irqsave(&kretprobe_lock, flags);
- hlist_for_each_entry_safe(ri, pos, next, &rp->used_instances, uflist) {
- ri->rp = NULL;
- hlist_del(&ri->uflist);
- }
- spin_unlock_irqrestore(&kretprobe_lock, flags);
- free_rp_inst(rp);
+static int __kprobes pre_handler_kretprobe(struct kprobe *p,
+ struct pt_regs *regs)
+{
+ return 0;
}
+#endif /* CONFIG_KRETPROBES */
+
static int __init init_kprobes(void)
{
int i, err = 0;
+ unsigned long offset = 0, size = 0;
+ char *modname, namebuf[128];
+ const char *symbol_name;
+ void *addr;
+ struct kprobe_blackpoint *kb;
/* FIXME allocate the probe table, currently defined statically */
/* initialize all list heads */
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
INIT_HLIST_HEAD(&kprobe_table[i]);
INIT_HLIST_HEAD(&kretprobe_inst_table[i]);
+ spin_lock_init(&(kretprobe_table_locks[i].lock));
+ }
+
+ /*
+ * Lookup and populate the kprobe_blacklist.
+ *
+ * Unlike the kretprobe blacklist, we'll need to determine
+ * the range of addresses that belong to the said functions,
+ * since a kprobe need not necessarily be at the beginning
+ * of a function.
+ */
+ for (kb = kprobe_blacklist; kb->name != NULL; kb++) {
+ kprobe_lookup_name(kb->name, addr);
+ if (!addr)
+ continue;
+
+ kb->start_addr = (unsigned long)addr;
+ symbol_name = kallsyms_lookup(kb->start_addr,
+ &size, &offset, &modname, namebuf);
+ if (!symbol_name)
+ kb->range = 0;
+ else
+ kb->range = size;
}
if (kretprobe_blacklist_size) {
err = arch_init_kprobes();
if (!err)
err = register_die_notifier(&kprobe_exceptions_nb);
+ kprobes_initialized = (err == 0);
if (!err)
init_test_probes();
EXPORT_SYMBOL_GPL(register_kprobe);
EXPORT_SYMBOL_GPL(unregister_kprobe);
+EXPORT_SYMBOL_GPL(register_kprobes);
+EXPORT_SYMBOL_GPL(unregister_kprobes);
EXPORT_SYMBOL_GPL(register_jprobe);
EXPORT_SYMBOL_GPL(unregister_jprobe);
-#ifdef CONFIG_KPROBES
+EXPORT_SYMBOL_GPL(register_jprobes);
+EXPORT_SYMBOL_GPL(unregister_jprobes);
EXPORT_SYMBOL_GPL(jprobe_return);
-#endif
-
-#ifdef CONFIG_KPROBES
EXPORT_SYMBOL_GPL(register_kretprobe);
EXPORT_SYMBOL_GPL(unregister_kretprobe);
-#endif
+EXPORT_SYMBOL_GPL(register_kretprobes);
+EXPORT_SYMBOL_GPL(unregister_kretprobes);
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff