#include <linux/hardirq.h>
#include <linux/kthread.h>
#include <linux/uaccess.h>
+#include <linux/kprobes.h>
#include <linux/ftrace.h>
#include <linux/sysctl.h>
#include <linux/ctype.h>
#include <linux/hash.h>
#include <linux/list.h>
+#include <asm/ftrace.h>
+
#include "trace.h"
/* ftrace_enabled is a method to turn ftrace on or off */
static int __register_ftrace_function(struct ftrace_ops *ops)
{
- /* Should never be called by interrupts */
+ /* should not be called from interrupt context */
spin_lock(&ftrace_lock);
ops->next = ftrace_list;
struct ftrace_ops **p;
int ret = 0;
+ /* should not be called from interrupt context */
spin_lock(&ftrace_lock);
/*
#ifdef CONFIG_DYNAMIC_FTRACE
+#ifndef CONFIG_FTRACE_MCOUNT_RECORD
+/*
+ * The hash lock is only needed when the recording of the mcount
+ * callers are dynamic. That is, by the caller themselves and
+ * not recorded via the compilation.
+ */
+static DEFINE_SPINLOCK(ftrace_hash_lock);
+#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags)
+#define ftrace_hash_unlock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags)
+#else
+/* This is protected via the ftrace_lock with MCOUNT_RECORD. */
+#define ftrace_hash_lock(flags) do { (void)flags; } while (0)
+#define ftrace_hash_unlock(flags) do { } while(0)
+#endif
+
static struct task_struct *ftraced_task;
enum {
};
static int ftrace_filtered;
+static int tracing_on;
+static int frozen_record_count;
static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
-static DEFINE_SPINLOCK(ftrace_shutdown_lock);
static DEFINE_MUTEX(ftraced_lock);
static DEFINE_MUTEX(ftrace_regex_lock);
static struct dyn_ftrace *ftrace_free_records;
+
+#ifdef CONFIG_KPROBES
+static inline void freeze_record(struct dyn_ftrace *rec)
+{
+ if (!(rec->flags & FTRACE_FL_FROZEN)) {
+ rec->flags |= FTRACE_FL_FROZEN;
+ frozen_record_count++;
+ }
+}
+
+static inline void unfreeze_record(struct dyn_ftrace *rec)
+{
+ if (rec->flags & FTRACE_FL_FROZEN) {
+ rec->flags &= ~FTRACE_FL_FROZEN;
+ frozen_record_count--;
+ }
+}
+
+static inline int record_frozen(struct dyn_ftrace *rec)
+{
+ return rec->flags & FTRACE_FL_FROZEN;
+}
+#else
+# define freeze_record(rec) ({ 0; })
+# define unfreeze_record(rec) ({ 0; })
+# define record_frozen(rec) ({ 0; })
+#endif /* CONFIG_KPROBES */
+
+int skip_trace(unsigned long ip)
+{
+ unsigned long fl;
+ struct dyn_ftrace *rec;
+ struct hlist_node *t;
+ struct hlist_head *head;
+
+ if (frozen_record_count == 0)
+ return 0;
+
+ head = &ftrace_hash[hash_long(ip, FTRACE_HASHBITS)];
+ hlist_for_each_entry_rcu(rec, t, head, node) {
+ if (rec->ip == ip) {
+ if (record_frozen(rec)) {
+ if (rec->flags & FTRACE_FL_FAILED)
+ return 1;
+
+ if (!(rec->flags & FTRACE_FL_CONVERTED))
+ return 1;
+
+ if (!tracing_on || !ftrace_enabled)
+ return 1;
+
+ if (ftrace_filtered) {
+ fl = rec->flags & (FTRACE_FL_FILTER |
+ FTRACE_FL_NOTRACE);
+ if (!fl || (fl & FTRACE_FL_NOTRACE))
+ return 1;
+ }
+ }
+ break;
+ }
+ }
+
+ return 0;
+}
+
static inline int
ftrace_ip_in_hash(unsigned long ip, unsigned long key)
{
static void ftrace_free_rec(struct dyn_ftrace *rec)
{
- /* no locking, only called from kstop_machine */
-
rec->ip = (unsigned long)ftrace_free_records;
ftrace_free_records = rec;
rec->flags |= FTRACE_FL_FREE;
}
+void ftrace_release(void *start, unsigned long size)
+{
+ struct dyn_ftrace *rec;
+ struct ftrace_page *pg;
+ unsigned long s = (unsigned long)start;
+ unsigned long e = s + size;
+ int i;
+
+ if (ftrace_disabled || !start)
+ return;
+
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+
+ for (pg = ftrace_pages_start; pg; pg = pg->next) {
+ for (i = 0; i < pg->index; i++) {
+ rec = &pg->records[i];
+
+ if ((rec->ip >= s) && (rec->ip < e))
+ ftrace_free_rec(rec);
+ }
+ }
+ spin_unlock(&ftrace_lock);
+
+}
+
static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
{
struct dyn_ftrace *rec;
unsigned long flags;
unsigned long key;
int resched;
- int atomic;
int cpu;
if (!ftrace_enabled || ftrace_disabled)
if (ftrace_ip_in_hash(ip, key))
goto out;
- atomic = irqs_disabled();
-
- spin_lock_irqsave(&ftrace_shutdown_lock, flags);
+ ftrace_hash_lock(flags);
/* This ip may have hit the hash before the lock */
if (ftrace_ip_in_hash(ip, key))
ftraced_trigger = 1;
out_unlock:
- spin_unlock_irqrestore(&ftrace_shutdown_lock, flags);
+ ftrace_hash_unlock(flags);
out:
per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
}
#define FTRACE_ADDR ((long)(ftrace_caller))
-#define MCOUNT_ADDR ((long)(mcount))
static int
__ftrace_replace_code(struct dyn_ftrace *rec,
if (rec->flags & FTRACE_FL_FAILED)
continue;
+ /* ignore updates to this record's mcount site */
+ if (get_kprobe((void *)rec->ip)) {
+ freeze_record(rec);
+ continue;
+ } else {
+ unfreeze_record(rec);
+ }
+
failed = __ftrace_replace_code(rec, old, new, enable);
if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
*/
__ftrace_update_code(NULL);
ftrace_replace_code(1);
- } else if (*command & FTRACE_DISABLE_CALLS)
+ tracing_on = 1;
+ } else if (*command & FTRACE_DISABLE_CALLS) {
ftrace_replace_code(0);
+ tracing_on = 0;
+ }
if (*command & FTRACE_UPDATE_TRACE_FUNC)
ftrace_update_ftrace_func(ftrace_trace_function);
static void ftrace_run_update_code(int command)
{
- stop_machine_run(__ftrace_modify_code, &command, NR_CPUS);
+ stop_machine(__ftrace_modify_code, &command, NULL);
}
void ftrace_disable_daemon(void)
static int __ftrace_update_code(void *ignore)
{
+ int i, save_ftrace_enabled;
+ cycle_t start, stop;
struct dyn_ftrace *p;
struct hlist_node *t, *n;
- int save_ftrace_enabled;
- cycle_t start, stop;
- int i;
+ struct hlist_head *head, temp_list;
/* Don't be recording funcs now */
ftrace_record_suspend++;
/* No locks needed, the machine is stopped! */
for (i = 0; i < FTRACE_HASHSIZE; i++) {
+ INIT_HLIST_HEAD(&temp_list);
+ head = &ftrace_hash[i];
+
/* all CPUS are stopped, we are safe to modify code */
- hlist_for_each_entry_safe(p, t, n, &ftrace_hash[i], node) {
+ hlist_for_each_entry_safe(p, t, n, head, node) {
/* Skip over failed records which have not been
* freed. */
if (p->flags & FTRACE_FL_FAILED)
if (p->flags & (FTRACE_FL_CONVERTED))
break;
+ /* Ignore updates to this record's mcount site.
+ * Reintroduce this record at the head of this
+ * bucket to attempt to "convert" it again if
+ * the kprobe on it is unregistered before the
+ * next run. */
+ if (get_kprobe((void *)p->ip)) {
+ ftrace_del_hash(p);
+ INIT_HLIST_NODE(&p->node);
+ hlist_add_head(&p->node, &temp_list);
+ freeze_record(p);
+ continue;
+ } else {
+ unfreeze_record(p);
+ }
+
+ /* convert record (i.e, patch mcount-call with NOP) */
if (ftrace_code_disable(p)) {
p->flags |= FTRACE_FL_CONVERTED;
ftrace_update_cnt++;
}
}
}
+
+ hlist_for_each_entry_safe(p, t, n, &temp_list, node) {
+ hlist_del(&p->node);
+ INIT_HLIST_NODE(&p->node);
+ hlist_add_head(&p->node, head);
+ }
}
stop = ftrace_now(raw_smp_processor_id());
!ftrace_enabled || !ftraced_trigger)
return 0;
- stop_machine_run(__ftrace_update_code, NULL, NR_CPUS);
+ stop_machine(__ftrace_update_code, NULL, NULL);
return 1;
}
-static int ftraced(void *ignore)
-{
- unsigned long usecs;
-
- while (!kthread_should_stop()) {
-
- set_current_state(TASK_INTERRUPTIBLE);
-
- /* check once a second */
- schedule_timeout(HZ);
-
- if (unlikely(ftrace_disabled))
- continue;
-
- mutex_lock(&ftrace_sysctl_lock);
- mutex_lock(&ftraced_lock);
- if (!ftraced_suspend && !ftraced_stop &&
- ftrace_update_code()) {
- usecs = nsecs_to_usecs(ftrace_update_time);
- if (ftrace_update_tot_cnt > 100000) {
- ftrace_update_tot_cnt = 0;
- pr_info("hm, dftrace overflow: %lu change%s"
- " (%lu total) in %lu usec%s\n",
- ftrace_update_cnt,
- ftrace_update_cnt != 1 ? "s" : "",
- ftrace_update_tot_cnt,
- usecs, usecs != 1 ? "s" : "");
- ftrace_disabled = 1;
- WARN_ON_ONCE(1);
- }
- }
- mutex_unlock(&ftraced_lock);
- mutex_unlock(&ftrace_sysctl_lock);
-
- ftrace_shutdown_replenish();
- }
- __set_current_state(TASK_RUNNING);
- return 0;
-}
-
-static int __init ftrace_dyn_table_alloc(void)
+static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
{
struct ftrace_page *pg;
int cnt;
pg = ftrace_pages = ftrace_pages_start;
- cnt = NR_TO_INIT / ENTRIES_PER_PAGE;
+ cnt = num_to_init / ENTRIES_PER_PAGE;
+ pr_info("ftrace: allocating %ld hash entries in %d pages\n",
+ num_to_init, cnt);
for (i = 0; i < cnt; i++) {
pg->next = (void *)get_zeroed_page(GFP_KERNEL);
(*pos)++;
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
retry:
if (iter->idx >= iter->pg->index) {
if (iter->pg->next) {
}
} else {
rec = &iter->pg->records[iter->idx++];
- if ((!(iter->flags & FTRACE_ITER_FAILURES) &&
+ if ((rec->flags & FTRACE_FL_FREE) ||
+
+ (!(iter->flags & FTRACE_ITER_FAILURES) &&
(rec->flags & FTRACE_FL_FAILED)) ||
((iter->flags & FTRACE_ITER_FAILURES) &&
- (!(rec->flags & FTRACE_FL_FAILED) ||
- (rec->flags & FTRACE_FL_FREE))) ||
-
- ((iter->flags & FTRACE_ITER_FILTER) &&
- !(rec->flags & FTRACE_FL_FILTER)) ||
+ !(rec->flags & FTRACE_FL_FAILED)) ||
((iter->flags & FTRACE_ITER_NOTRACE) &&
!(rec->flags & FTRACE_FL_NOTRACE))) {
goto retry;
}
}
+ spin_unlock(&ftrace_lock);
iter->pos = *pos;
unsigned long type = enable ? FTRACE_FL_FILTER : FTRACE_FL_NOTRACE;
unsigned i;
- /* keep kstop machine from running */
- preempt_disable();
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
if (enable)
ftrace_filtered = 0;
pg = ftrace_pages_start;
}
pg = pg->next;
}
- preempt_enable();
+ spin_unlock(&ftrace_lock);
}
static int
}
}
- /* keep kstop machine from running */
- preempt_disable();
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
if (enable)
ftrace_filtered = 1;
pg = ftrace_pages_start;
}
pg = pg->next;
}
- preempt_enable();
+ spin_unlock(&ftrace_lock);
}
static ssize_t
fs_initcall(ftrace_init_debugfs);
+#ifdef CONFIG_FTRACE_MCOUNT_RECORD
+static int ftrace_convert_nops(unsigned long *start,
+ unsigned long *end)
+{
+ unsigned long *p;
+ unsigned long addr;
+ unsigned long flags;
+
+ p = start;
+ while (p < end) {
+ addr = ftrace_call_adjust(*p++);
+ /* should not be called from interrupt context */
+ spin_lock(&ftrace_lock);
+ ftrace_record_ip(addr);
+ spin_unlock(&ftrace_lock);
+ ftrace_shutdown_replenish();
+ }
+
+ /* p is ignored */
+ local_irq_save(flags);
+ __ftrace_update_code(p);
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+void ftrace_init_module(unsigned long *start, unsigned long *end)
+{
+ if (ftrace_disabled || start == end)
+ return;
+ ftrace_convert_nops(start, end);
+}
+
+extern unsigned long __start_mcount_loc[];
+extern unsigned long __stop_mcount_loc[];
+
+void __init ftrace_init(void)
+{
+ unsigned long count, addr, flags;
+ int ret;
+
+ /* Keep the ftrace pointer to the stub */
+ addr = (unsigned long)ftrace_stub;
+
+ local_irq_save(flags);
+ ftrace_dyn_arch_init(&addr);
+ local_irq_restore(flags);
+
+ /* ftrace_dyn_arch_init places the return code in addr */
+ if (addr)
+ goto failed;
+
+ count = __stop_mcount_loc - __start_mcount_loc;
+
+ ret = ftrace_dyn_table_alloc(count);
+ if (ret)
+ goto failed;
+
+ last_ftrace_enabled = ftrace_enabled = 1;
+
+ ret = ftrace_convert_nops(__start_mcount_loc,
+ __stop_mcount_loc);
+
+ return;
+ failed:
+ ftrace_disabled = 1;
+}
+#else /* CONFIG_FTRACE_MCOUNT_RECORD */
+static int ftraced(void *ignore)
+{
+ unsigned long usecs;
+
+ while (!kthread_should_stop()) {
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ /* check once a second */
+ schedule_timeout(HZ);
+
+ if (unlikely(ftrace_disabled))
+ continue;
+
+ mutex_lock(&ftrace_sysctl_lock);
+ mutex_lock(&ftraced_lock);
+ if (!ftraced_suspend && !ftraced_stop &&
+ ftrace_update_code()) {
+ usecs = nsecs_to_usecs(ftrace_update_time);
+ if (ftrace_update_tot_cnt > 100000) {
+ ftrace_update_tot_cnt = 0;
+ pr_info("hm, dftrace overflow: %lu change%s"
+ " (%lu total) in %lu usec%s\n",
+ ftrace_update_cnt,
+ ftrace_update_cnt != 1 ? "s" : "",
+ ftrace_update_tot_cnt,
+ usecs, usecs != 1 ? "s" : "");
+ ftrace_disabled = 1;
+ WARN_ON_ONCE(1);
+ }
+ }
+ mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_sysctl_lock);
+
+ ftrace_shutdown_replenish();
+ }
+ __set_current_state(TASK_RUNNING);
+ return 0;
+}
+
static int __init ftrace_dynamic_init(void)
{
struct task_struct *p;
addr = (unsigned long)ftrace_record_ip;
- stop_machine_run(ftrace_dyn_arch_init, &addr, NR_CPUS);
+ stop_machine(ftrace_dyn_arch_init, &addr, NULL);
/* ftrace_dyn_arch_init places the return code in addr */
if (addr) {
goto failed;
}
- ret = ftrace_dyn_table_alloc();
+ ret = ftrace_dyn_table_alloc(NR_TO_INIT);
if (ret)
goto failed;
}
core_initcall(ftrace_dynamic_init);
+#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
+
#else
# define ftrace_startup() do { } while (0)
# define ftrace_shutdown() do { } while (0)
#endif /* CONFIG_DYNAMIC_FTRACE */
/**
+ * ftrace_kill_atomic - kill ftrace from critical sections
+ *
+ * This function should be used by panic code. It stops ftrace
+ * but in a not so nice way. If you need to simply kill ftrace
+ * from a non-atomic section, use ftrace_kill.
+ */
+void ftrace_kill_atomic(void)
+{
+ ftrace_disabled = 1;
+ ftrace_enabled = 0;
+#ifdef CONFIG_DYNAMIC_FTRACE
+ ftraced_suspend = -1;
+#endif
+ clear_ftrace_function();
+}
+
+/**
* ftrace_kill - totally shutdown ftrace
*
* This is a safety measure. If something was detected that seems
git://ftp.safe.ca / safe / jmp / linux-2.6 / blobdiff