return 0;
}
-/* Return true(!0) if the kprobe is disarmed. Note: p must be on hash list */
-static inline int kprobe_disarmed(struct kprobe *p)
+/* Return true if the kprobe is disarmed. Note: p must be on hash list */
+bool kprobe_disarmed(struct kprobe *p)
{
struct optimized_kprobe *op;
*/
static void do_optimize_kprobes(void)
{
+ lockdep_assert_held(&text_mutex);
/*
* The optimization/unoptimization refers online_cpus via
* stop_machine() and cpu-hotplug modifies online_cpus.
list_empty(&optimizing_list))
return;
- mutex_lock(&text_mutex);
arch_optimize_kprobes(&optimizing_list);
- mutex_unlock(&text_mutex);
}
/*
{
struct optimized_kprobe *op, *tmp;
+ lockdep_assert_held(&text_mutex);
/* See comment in do_optimize_kprobes() */
lockdep_assert_cpus_held();
if (list_empty(&unoptimizing_list))
return;
- mutex_lock(&text_mutex);
arch_unoptimize_kprobes(&unoptimizing_list, &freeing_list);
/* Loop free_list for disarming */
list_for_each_entry_safe(op, tmp, &freeing_list, list) {
+ /* Switching from detour code to origin */
+ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
/* Disarm probes if marked disabled */
if (kprobe_disabled(&op->kp))
arch_disarm_kprobe(&op->kp);
} else
list_del_init(&op->list);
}
- mutex_unlock(&text_mutex);
}
/* Reclaim all kprobes on the free_list */
struct optimized_kprobe *op, *tmp;
list_for_each_entry_safe(op, tmp, &freeing_list, list) {
- BUG_ON(!kprobe_unused(&op->kp));
list_del_init(&op->list);
+ if (WARN_ON_ONCE(!kprobe_unused(&op->kp))) {
+ /*
+ * This must not happen, but if there is a kprobe
+ * still in use, keep it on kprobes hash list.
+ */
+ continue;
+ }
free_aggr_kprobe(&op->kp);
}
}
{
mutex_lock(&kprobe_mutex);
cpus_read_lock();
+ mutex_lock(&text_mutex);
/* Lock modules while optimizing kprobes */
mutex_lock(&module_mutex);
do_unoptimize_kprobes();
/*
- * Step 2: Wait for quiesence period to ensure all running interrupts
- * are done. Because optprobe may modify multiple instructions
- * there is a chance that Nth instruction is interrupted. In that
- * case, running interrupt can return to 2nd-Nth byte of jump
- * instruction. This wait is for avoiding it.
+ * Step 2: Wait for quiesence period to ensure all potentially
+ * preempted tasks to have normally scheduled. Because optprobe
+ * may modify multiple instructions, there is a chance that Nth
+ * instruction is preempted. In that case, such tasks can return
+ * to 2nd-Nth byte of jump instruction. This wait is for avoiding it.
+ * Note that on non-preemptive kernel, this is transparently converted
+ * to synchronoze_sched() to wait for all interrupts to have completed.
*/
- synchronize_sched();
+ synchronize_rcu_tasks();
/* Step 3: Optimize kprobes after quiesence period */
do_optimize_kprobes();
do_free_cleaned_kprobes();
mutex_unlock(&module_mutex);
+ mutex_unlock(&text_mutex);
cpus_read_unlock();
- mutex_unlock(&kprobe_mutex);
/* Step 5: Kick optimizer again if needed */
if (!list_empty(&optimizing_list) || !list_empty(&unoptimizing_list))
kick_kprobe_optimizer();
+
+ mutex_unlock(&kprobe_mutex);
}
/* Wait for completing optimization and unoptimization */
mutex_unlock(&kprobe_mutex);
}
+bool optprobe_queued_unopt(struct optimized_kprobe *op)
+{
+ struct optimized_kprobe *_op;
+
+ list_for_each_entry(_op, &unoptimizing_list, list) {
+ if (op == _op)
+ return true;
+ }
+
+ return false;
+}
+
/* Optimize kprobe if p is ready to be optimized */
static void optimize_kprobe(struct kprobe *p)
{
return;
/* Check if it is already optimized. */
- if (op->kp.flags & KPROBE_FLAG_OPTIMIZED)
+ if (op->kp.flags & KPROBE_FLAG_OPTIMIZED) {
+ if (optprobe_queued_unopt(op)) {
+ /* This is under unoptimizing. Just dequeue the probe */
+ list_del_init(&op->list);
+ }
return;
+ }
op->kp.flags |= KPROBE_FLAG_OPTIMIZED;
- if (!list_empty(&op->list))
- /* This is under unoptimizing. Just dequeue the probe */
- list_del_init(&op->list);
- else {
- list_add(&op->list, &optimizing_list);
- kick_kprobe_optimizer();
- }
+ /* On unoptimizing/optimizing_list, op must have OPTIMIZED flag */
+ if (WARN_ON_ONCE(!list_empty(&op->list)))
+ return;
+
+ list_add(&op->list, &optimizing_list);
+ kick_kprobe_optimizer();
}
/* Short cut to direct unoptimizing */
{
lockdep_assert_cpus_held();
arch_unoptimize_kprobe(op);
+ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
if (kprobe_disabled(&op->kp))
arch_disarm_kprobe(&op->kp);
}
return; /* This is not an optprobe nor optimized */
op = container_of(p, struct optimized_kprobe, kp);
- if (!kprobe_optimized(p)) {
- /* Unoptimized or unoptimizing case */
- if (force && !list_empty(&op->list)) {
- /*
- * Only if this is unoptimizing kprobe and forced,
- * forcibly unoptimize it. (No need to unoptimize
- * unoptimized kprobe again :)
- */
- list_del_init(&op->list);
- force_unoptimize_kprobe(op);
- }
+ if (!kprobe_optimized(p))
return;
- }
- op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
if (!list_empty(&op->list)) {
- /* Dequeue from the optimization queue */
- list_del_init(&op->list);
+ if (optprobe_queued_unopt(op)) {
+ /* Queued in unoptimizing queue */
+ if (force) {
+ /*
+ * Forcibly unoptimize the kprobe here, and queue it
+ * in the freeing list for release afterwards.
+ */
+ force_unoptimize_kprobe(op);
+ list_move(&op->list, &freeing_list);
+ }
+ } else {
+ /* Dequeue from the optimizing queue */
+ list_del_init(&op->list);
+ op->kp.flags &= ~KPROBE_FLAG_OPTIMIZED;
+ }
return;
}
+
/* Optimized kprobe case */
- if (force)
+ if (force) {
/* Forcibly update the code: this is a special case */
force_unoptimize_kprobe(op);
- else {
+ } else {
list_add(&op->list, &unoptimizing_list);
kick_kprobe_optimizer();
}
}
/* Cancel unoptimizing for reusing */
-static void reuse_unused_kprobe(struct kprobe *ap)
+static int reuse_unused_kprobe(struct kprobe *ap)
{
struct optimized_kprobe *op;
/* Enable the probe again */
ap->flags &= ~KPROBE_FLAG_DISABLED;
/* Optimize it again (remove from op->list) */
- BUG_ON(!kprobe_optready(ap));
+ if (!kprobe_optready(ap))
+ return -EINVAL;
+
optimize_kprobe(ap);
+ return 0;
}
/* Remove optimized instructions */
#define kprobe_disarmed(p) kprobe_disabled(p)
#define wait_for_kprobe_optimizer() do {} while (0)
-/* There should be no unused kprobes can be reused without optimization */
-static void reuse_unused_kprobe(struct kprobe *ap)
+static int reuse_unused_kprobe(struct kprobe *ap)
{
+ /*
+ * If the optimized kprobe is NOT supported, the aggr kprobe is
+ * released at the same time that the last aggregated kprobe is
+ * unregistered.
+ * Thus there should be no chance to reuse unused kprobe.
+ */
printk(KERN_ERR "Error: There should be no unused kprobe here.\n");
- BUG_ON(kprobe_unused(ap));
+ return -EINVAL;
}
static void free_aggr_kprobe(struct kprobe *p)
}
NOKPROBE_SYMBOL(kretprobe_table_unlock);
+struct kprobe kprobe_busy = {
+ .addr = (void *) get_kprobe,
+};
+
+void kprobe_busy_begin(void)
+{
+ struct kprobe_ctlblk *kcb;
+
+ preempt_disable();
+ __this_cpu_write(current_kprobe, &kprobe_busy);
+ kcb = get_kprobe_ctlblk();
+ kcb->kprobe_status = KPROBE_HIT_ACTIVE;
+}
+
+void kprobe_busy_end(void)
+{
+ __this_cpu_write(current_kprobe, NULL);
+ preempt_enable();
+}
+
/*
* This function is called from finish_task_switch when task tk becomes dead,
* so that we can recycle any function-return probe instances associated
/* Early boot. kretprobe_table_locks not yet initialized. */
return;
+ kprobe_busy_begin();
+
INIT_HLIST_HEAD(&empty_rp);
hash = hash_ptr(tk, KPROBE_HASH_BITS);
head = &kretprobe_inst_table[hash];
hlist_del(&ri->hlist);
kfree(ri);
}
+
+ kprobe_busy_end();
}
NOKPROBE_SYMBOL(kprobe_flush_task);
goto out;
}
init_aggr_kprobe(ap, orig_p);
- } else if (kprobe_unused(ap))
+ } else if (kprobe_unused(ap)) {
/* This probe is going to die. Rescue it */
- reuse_unused_kprobe(ap);
+ ret = reuse_unused_kprobe(ap);
+ if (ret)
+ goto out;
+ }
if (kprobe_gone(ap)) {
/*
preempt_disable();
/* Ensure it is not in reserved area nor out of text */
- if (!kernel_text_address((unsigned long) p->addr) ||
+ if (!(core_kernel_text((unsigned long) p->addr) ||
+ is_module_text_address((unsigned long) p->addr)) ||
+ in_gate_area_no_mm((unsigned long) p->addr) ||
within_kprobe_blacklist((unsigned long) p->addr) ||
- jump_label_text_reserved(p->addr, p->addr)) {
+ jump_label_text_reserved(p->addr, p->addr) ||
+ find_bug((unsigned long)p->addr)) {
ret = -EINVAL;
goto out;
}
/* Try to disarm and disable this/parent probe */
if (p == orig_p || aggr_kprobe_disabled(orig_p)) {
/*
- * If kprobes_all_disarmed is set, orig_p
- * should have already been disarmed, so
- * skip unneed disarming process.
+ * Don't be lazy here. Even if 'kprobes_all_disarmed'
+ * is false, 'orig_p' might not have been armed yet.
+ * Note arm_all_kprobes() __tries__ to arm all kprobes
+ * on the best effort basis.
*/
- if (!kprobes_all_disarmed)
+ if (!kprobes_all_disarmed && !kprobe_disabled(orig_p))
disarm_kprobe(orig_p, true);
+
orig_p->flags |= KPROBE_FLAG_DISABLED;
}
}
if (!kprobe_on_func_entry(rp->kp.addr, rp->kp.symbol_name, rp->kp.offset))
return -EINVAL;
+ /* If only rp->kp.addr is specified, check reregistering kprobes */
+ if (rp->kp.addr && check_kprobe_rereg(&rp->kp))
+ return -EINVAL;
+
if (kretprobe_blacklist_size) {
addr = kprobe_addr(&rp->kp);
if (IS_ERR(addr))
}
}
+ if (rp->data_size > KRETPROBE_MAX_DATA_SIZE)
+ return -E2BIG;
+
rp->kp.pre_handler = pre_handler_kretprobe;
rp->kp.post_handler = NULL;
rp->kp.fault_handler = NULL;
{
struct kprobe *kp;
+ if (WARN_ON_ONCE(kprobe_gone(p)))
+ return;
+
p->flags |= KPROBE_FLAG_GONE;
if (kprobe_aggrprobe(p)) {
/*
* the original probed function (which will be freed soon) any more.
*/
arch_remove_kprobe(p);
+
+ /*
+ * The module is going away. We should disarm the kprobe which
+ * is using ftrace, because ftrace framework is still available at
+ * MODULE_STATE_GOING notification.
+ */
+ if (kprobe_ftrace(p) && !kprobe_disabled(p) && !kprobes_all_disarmed)
+ disarm_kprobe_ftrace(p);
}
/* Disable one kprobe */
mutex_lock(&kprobe_mutex);
for (i = 0; i < KPROBE_TABLE_SIZE; i++) {
head = &kprobe_table[i];
- hlist_for_each_entry_rcu(p, head, hlist)
+ hlist_for_each_entry_rcu(p, head, hlist) {
+ if (kprobe_gone(p))
+ continue;
+
if (within_module_init((unsigned long)p->addr, mod) ||
(checkcore &&
within_module_core((unsigned long)p->addr, mod))) {
*/
kill_kprobe(p);
}
+ }
}
mutex_unlock(&kprobe_mutex);
return NOTIFY_DONE;
if (!dir)
return -ENOMEM;
- file = debugfs_create_file("list", 0444, dir, NULL,
+ file = debugfs_create_file("list", 0400, dir, NULL,
&debugfs_kprobes_operations);
if (!file)
goto error;
if (!file)
goto error;
- file = debugfs_create_file("blacklist", 0444, dir, NULL,
+ file = debugfs_create_file("blacklist", 0400, dir, NULL,
&debugfs_kprobe_blacklist_ops);
if (!file)
goto error;
projects / thirdparty / kernel / stable.git / blobdiff