#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"
+#define FTRACE_WARN_ON(cond) \
+ do { \
+ if (WARN_ON(cond)) \
+ ftrace_kill(); \
+ } while (0)
+
+#define FTRACE_WARN_ON_ONCE(cond) \
+ do { \
+ if (WARN_ON_ONCE(cond)) \
+ ftrace_kill(); \
+ } while (0)
+
/* ftrace_enabled is a method to turn ftrace on or off */
int ftrace_enabled __read_mostly;
static int last_ftrace_enabled;
}
#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_unlock_irqrestore(&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)
+# error Dynamic ftrace depends on MCOUNT_RECORD
#endif
/*
*/
static unsigned long mcount_addr = MCOUNT_ADDR;
-static struct task_struct *ftraced_task;
-
enum {
FTRACE_ENABLE_CALLS = (1 << 0),
FTRACE_DISABLE_CALLS = (1 << 1),
static int ftrace_filtered;
static int tracing_on;
-static int frozen_record_count;
-static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
+static LIST_HEAD(ftrace_new_addrs);
-static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
-
-static DEFINE_MUTEX(ftraced_lock);
static DEFINE_MUTEX(ftrace_regex_lock);
struct ftrace_page {
static struct ftrace_page *ftrace_pages_start;
static struct ftrace_page *ftrace_pages;
-static int ftraced_trigger;
-static int ftraced_suspend;
-static int ftraced_stop;
-
-static int ftrace_record_suspend;
-
static struct dyn_ftrace *ftrace_free_records;
#ifdef CONFIG_KPROBES
+
+static int frozen_record_count;
+
static inline void freeze_record(struct dyn_ftrace *rec)
{
if (!(rec->flags & FTRACE_FL_FROZEN)) {
# 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)
-{
- struct dyn_ftrace *p;
- struct hlist_node *t;
- int found = 0;
-
- hlist_for_each_entry_rcu(p, t, &ftrace_hash[key], node) {
- if (p->ip == ip) {
- found = 1;
- break;
- }
- }
-
- return found;
-}
-
-static inline void
-ftrace_add_hash(struct dyn_ftrace *node, unsigned long key)
-{
- hlist_add_head_rcu(&node->node, &ftrace_hash[key]);
-}
-
-/* called from kstop_machine */
-static inline void ftrace_del_hash(struct dyn_ftrace *node)
-{
- hlist_del(&node->node);
-}
-
static void ftrace_free_rec(struct dyn_ftrace *rec)
{
rec->ip = (unsigned long)ftrace_free_records;
}
}
spin_unlock(&ftrace_lock);
-
}
static struct dyn_ftrace *ftrace_alloc_dyn_node(unsigned long ip)
rec = ftrace_free_records;
if (unlikely(!(rec->flags & FTRACE_FL_FREE))) {
- WARN_ON_ONCE(1);
+ FTRACE_WARN_ON_ONCE(1);
ftrace_free_records = NULL;
- ftrace_disabled = 1;
- ftrace_enabled = 0;
return NULL;
}
}
if (ftrace_pages->index == ENTRIES_PER_PAGE) {
- if (!ftrace_pages->next)
- return NULL;
+ if (!ftrace_pages->next) {
+ /* allocate another page */
+ ftrace_pages->next =
+ (void *)get_zeroed_page(GFP_KERNEL);
+ if (!ftrace_pages->next)
+ return NULL;
+ }
ftrace_pages = ftrace_pages->next;
}
return &ftrace_pages->records[ftrace_pages->index++];
}
-static void
+static struct dyn_ftrace *
ftrace_record_ip(unsigned long ip)
{
- struct dyn_ftrace *node;
- unsigned long flags;
- unsigned long key;
- int resched;
- int cpu;
+ struct dyn_ftrace *rec;
if (!ftrace_enabled || ftrace_disabled)
- return;
-
- resched = need_resched();
- preempt_disable_notrace();
-
- /*
- * We simply need to protect against recursion.
- * Use the the raw version of smp_processor_id and not
- * __get_cpu_var which can call debug hooks that can
- * cause a recursive crash here.
- */
- cpu = raw_smp_processor_id();
- per_cpu(ftrace_shutdown_disable_cpu, cpu)++;
- if (per_cpu(ftrace_shutdown_disable_cpu, cpu) != 1)
- goto out;
-
- if (unlikely(ftrace_record_suspend))
- goto out;
-
- key = hash_long(ip, FTRACE_HASHBITS);
-
- WARN_ON_ONCE(key >= FTRACE_HASHSIZE);
-
- if (ftrace_ip_in_hash(ip, key))
- goto out;
-
- ftrace_hash_lock(flags);
+ return NULL;
- /* This ip may have hit the hash before the lock */
- if (ftrace_ip_in_hash(ip, key))
- goto out_unlock;
-
- node = ftrace_alloc_dyn_node(ip);
- if (!node)
- goto out_unlock;
-
- node->ip = ip;
-
- ftrace_add_hash(node, key);
+ rec = ftrace_alloc_dyn_node(ip);
+ if (!rec)
+ return NULL;
- ftraced_trigger = 1;
+ rec->ip = ip;
- out_unlock:
- ftrace_hash_unlock(flags);
- out:
- per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
+ list_add(&rec->list, &ftrace_new_addrs);
- /* prevent recursion with scheduler */
- if (resched)
- preempt_enable_no_resched_notrace();
- else
- preempt_enable_notrace();
+ return rec;
}
#define FTRACE_ADDR ((long)(ftrace_caller))
static int
__ftrace_replace_code(struct dyn_ftrace *rec,
- unsigned char *old, unsigned char *new, int enable)
+ unsigned char *nop, int enable)
{
unsigned long ip, fl;
+ unsigned char *call, *old, *new;
ip = rec->ip;
- if (ftrace_filtered && enable) {
+ /*
+ * If this record is not to be traced and
+ * it is not enabled then do nothing.
+ *
+ * If this record is not to be traced and
+ * it is enabled then disabled it.
+ *
+ */
+ if (rec->flags & FTRACE_FL_NOTRACE) {
+ if (rec->flags & FTRACE_FL_ENABLED)
+ rec->flags &= ~FTRACE_FL_ENABLED;
+ else
+ return 0;
+
+ } else if (ftrace_filtered && enable) {
/*
- * If filtering is on:
- *
- * If this record is set to be filtered and
- * is enabled then do nothing.
- *
- * If this record is set to be filtered and
- * it is not enabled, enable it.
- *
- * If this record is not set to be filtered
- * and it is not enabled do nothing.
- *
- * If this record is set not to trace then
- * do nothing.
- *
- * If this record is set not to trace and
- * it is enabled then disable it.
- *
- * If this record is not set to be filtered and
- * it is enabled, disable it.
+ * Filtering is on:
*/
- fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE |
- FTRACE_FL_ENABLED);
+ fl = rec->flags & (FTRACE_FL_FILTER | FTRACE_FL_ENABLED);
- if ((fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED)) ||
- (fl == (FTRACE_FL_FILTER | FTRACE_FL_NOTRACE)) ||
- !fl || (fl == FTRACE_FL_NOTRACE))
+ /* Record is filtered and enabled, do nothing */
+ if (fl == (FTRACE_FL_FILTER | FTRACE_FL_ENABLED))
return 0;
- /*
- * If it is enabled disable it,
- * otherwise enable it!
- */
- if (fl & FTRACE_FL_ENABLED) {
- /* swap new and old */
- new = old;
- old = ftrace_call_replace(ip, FTRACE_ADDR);
+ /* Record is not filtered and is not enabled do nothing */
+ if (!fl)
+ return 0;
+
+ /* Record is not filtered but enabled, disable it */
+ if (fl == FTRACE_FL_ENABLED)
rec->flags &= ~FTRACE_FL_ENABLED;
- } else {
- new = ftrace_call_replace(ip, FTRACE_ADDR);
+ else
+ /* Otherwise record is filtered but not enabled, enable it */
rec->flags |= FTRACE_FL_ENABLED;
- }
} else {
+ /* Disable or not filtered */
if (enable) {
- /*
- * If this record is set not to trace and is
- * not enabled, do nothing.
- */
- fl = rec->flags & (FTRACE_FL_NOTRACE | FTRACE_FL_ENABLED);
- if (fl == FTRACE_FL_NOTRACE)
- return 0;
-
- new = ftrace_call_replace(ip, FTRACE_ADDR);
- } else
- old = ftrace_call_replace(ip, FTRACE_ADDR);
-
- if (enable) {
+ /* if record is enabled, do nothing */
if (rec->flags & FTRACE_FL_ENABLED)
return 0;
+
rec->flags |= FTRACE_FL_ENABLED;
+
} else {
+
+ /* if record is not enabled do nothing */
if (!(rec->flags & FTRACE_FL_ENABLED))
return 0;
+
rec->flags &= ~FTRACE_FL_ENABLED;
}
}
+ call = ftrace_call_replace(ip, FTRACE_ADDR);
+
+ if (rec->flags & FTRACE_FL_ENABLED) {
+ old = nop;
+ new = call;
+ } else {
+ old = call;
+ new = nop;
+ }
+
return ftrace_modify_code(ip, old, new);
}
static void ftrace_replace_code(int enable)
{
int i, failed;
- unsigned char *new = NULL, *old = NULL;
+ unsigned char *nop = NULL;
struct dyn_ftrace *rec;
struct ftrace_page *pg;
- if (enable)
- old = ftrace_nop_replace();
- else
- new = ftrace_nop_replace();
+ nop = ftrace_nop_replace();
for (pg = ftrace_pages_start; pg; pg = pg->next) {
for (i = 0; i < pg->index; i++) {
unfreeze_record(rec);
}
- failed = __ftrace_replace_code(rec, old, new, enable);
+ failed = __ftrace_replace_code(rec, nop, enable);
if (failed && (rec->flags & FTRACE_FL_CONVERTED)) {
rec->flags |= FTRACE_FL_FAILED;
if ((system_state == SYSTEM_BOOTING) ||
!core_kernel_text(rec->ip)) {
- ftrace_del_hash(rec);
ftrace_free_rec(rec);
}
}
}
}
-static void ftrace_shutdown_replenish(void)
-{
- if (ftrace_pages->next)
- return;
-
- /* allocate another page */
- ftrace_pages->next = (void *)get_zeroed_page(GFP_KERNEL);
-}
-
static void print_ip_ins(const char *fmt, unsigned char *p)
{
int i;
{
unsigned long ip;
unsigned char *nop, *call;
- int failed;
+ int ret;
ip = rec->ip;
nop = ftrace_nop_replace();
call = ftrace_call_replace(ip, mcount_addr);
- failed = ftrace_modify_code(ip, call, nop);
- if (failed) {
- switch (failed) {
- case 1:
- WARN_ON_ONCE(1);
+ ret = ftrace_modify_code(ip, call, nop);
+ if (ret) {
+ switch (ret) {
+ case -EFAULT:
+ FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace faulted on modifying ");
print_ip_sym(ip);
break;
- case 2:
- WARN_ON_ONCE(1);
+ case -EINVAL:
+ FTRACE_WARN_ON_ONCE(1);
pr_info("ftrace failed to modify ");
print_ip_sym(ip);
print_ip_ins(" expected: ", call);
print_ip_ins(" replace: ", nop);
printk(KERN_CONT "\n");
break;
+ case -EPERM:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on writing ");
+ print_ip_sym(ip);
+ break;
+ default:
+ FTRACE_WARN_ON_ONCE(1);
+ pr_info("ftrace faulted on unknown error ");
+ print_ip_sym(ip);
}
rec->flags |= FTRACE_FL_FAILED;
return 1;
}
-static int __ftrace_update_code(void *ignore);
-
static int __ftrace_modify_code(void *data)
{
- unsigned long addr;
int *command = data;
if (*command & FTRACE_ENABLE_CALLS) {
- /*
- * Update any recorded ips now that we have the
- * machine stopped
- */
- __ftrace_update_code(NULL);
ftrace_replace_code(1);
tracing_on = 1;
} else if (*command & FTRACE_DISABLE_CALLS) {
if (*command & FTRACE_UPDATE_TRACE_FUNC)
ftrace_update_ftrace_func(ftrace_trace_function);
- if (*command & FTRACE_ENABLE_MCOUNT) {
- addr = (unsigned long)ftrace_record_ip;
- ftrace_mcount_set(&addr);
- } else if (*command & FTRACE_DISABLE_MCOUNT) {
- addr = (unsigned long)ftrace_stub;
- ftrace_mcount_set(&addr);
- }
-
return 0;
}
stop_machine(__ftrace_modify_code, &command, NULL);
}
-void ftrace_disable_daemon(void)
-{
- /* Stop the daemon from calling kstop_machine */
- mutex_lock(&ftraced_lock);
- ftraced_stop = 1;
- mutex_unlock(&ftraced_lock);
-
- ftrace_force_update();
-}
-
-void ftrace_enable_daemon(void)
-{
- mutex_lock(&ftraced_lock);
- ftraced_stop = 0;
- mutex_unlock(&ftraced_lock);
-
- ftrace_force_update();
-}
-
static ftrace_func_t saved_ftrace_func;
+static int ftrace_start;
+static DEFINE_MUTEX(ftrace_start_lock);
static void ftrace_startup(void)
{
if (unlikely(ftrace_disabled))
return;
- mutex_lock(&ftraced_lock);
- ftraced_suspend++;
- if (ftraced_suspend == 1)
- command |= FTRACE_ENABLE_CALLS;
+ mutex_lock(&ftrace_start_lock);
+ ftrace_start++;
+ command |= FTRACE_ENABLE_CALLS;
if (saved_ftrace_func != ftrace_trace_function) {
saved_ftrace_func = ftrace_trace_function;
ftrace_run_update_code(command);
out:
- mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_start_lock);
}
static void ftrace_shutdown(void)
if (unlikely(ftrace_disabled))
return;
- mutex_lock(&ftraced_lock);
- ftraced_suspend--;
- if (!ftraced_suspend)
+ mutex_lock(&ftrace_start_lock);
+ ftrace_start--;
+ if (!ftrace_start)
command |= FTRACE_DISABLE_CALLS;
if (saved_ftrace_func != ftrace_trace_function) {
ftrace_run_update_code(command);
out:
- mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_start_lock);
}
static void ftrace_startup_sysctl(void)
if (unlikely(ftrace_disabled))
return;
- mutex_lock(&ftraced_lock);
+ mutex_lock(&ftrace_start_lock);
/* Force update next time */
saved_ftrace_func = NULL;
- /* ftraced_suspend is true if we want ftrace running */
- if (ftraced_suspend)
+ /* ftrace_start is true if we want ftrace running */
+ if (ftrace_start)
command |= FTRACE_ENABLE_CALLS;
ftrace_run_update_code(command);
- mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_start_lock);
}
static void ftrace_shutdown_sysctl(void)
if (unlikely(ftrace_disabled))
return;
- mutex_lock(&ftraced_lock);
- /* ftraced_suspend is true if ftrace is running */
- if (ftraced_suspend)
+ mutex_lock(&ftrace_start_lock);
+ /* ftrace_start is true if ftrace is running */
+ if (ftrace_start)
command |= FTRACE_DISABLE_CALLS;
ftrace_run_update_code(command);
- mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_start_lock);
}
static cycle_t ftrace_update_time;
static unsigned long ftrace_update_cnt;
unsigned long ftrace_update_tot_cnt;
-static int __ftrace_update_code(void *ignore)
+static int ftrace_update_code(void)
{
- int i, save_ftrace_enabled;
+ struct dyn_ftrace *p, *t;
cycle_t start, stop;
- struct dyn_ftrace *p;
- struct hlist_node *t, *n;
- struct hlist_head *head, temp_list;
-
- /* Don't be recording funcs now */
- ftrace_record_suspend++;
- save_ftrace_enabled = ftrace_enabled;
- ftrace_enabled = 0;
start = ftrace_now(raw_smp_processor_id());
ftrace_update_cnt = 0;
- /* 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, head, node) {
- /* Skip over failed records which have not been
- * freed. */
- if (p->flags & FTRACE_FL_FAILED)
- continue;
-
- /* Unconverted records are always at the head of the
- * hash bucket. Once we encounter a converted record,
- * simply skip over to the next bucket. Saves ftraced
- * some processor cycles (ftrace does its bid for
- * global warming :-p ). */
- if (p->flags & (FTRACE_FL_CONVERTED))
- break;
+ list_for_each_entry_safe(p, t, &ftrace_new_addrs, list) {
- /* 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);
- }
+ /* If something went wrong, bail without enabling anything */
+ if (unlikely(ftrace_disabled))
+ return -1;
- /* convert record (i.e, patch mcount-call with NOP) */
- if (ftrace_code_disable(p)) {
- p->flags |= FTRACE_FL_CONVERTED;
- ftrace_update_cnt++;
- } else {
- if ((system_state == SYSTEM_BOOTING) ||
- !core_kernel_text(p->ip)) {
- ftrace_del_hash(p);
- ftrace_free_rec(p);
- }
- }
- }
+ list_del_init(&p->list);
- 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);
- }
+ /* convert record (i.e, patch mcount-call with NOP) */
+ if (ftrace_code_disable(p)) {
+ p->flags |= FTRACE_FL_CONVERTED;
+ ftrace_update_cnt++;
+ } else
+ ftrace_free_rec(p);
}
stop = ftrace_now(raw_smp_processor_id());
ftrace_update_time = stop - start;
ftrace_update_tot_cnt += ftrace_update_cnt;
- ftraced_trigger = 0;
-
- ftrace_enabled = save_ftrace_enabled;
- ftrace_record_suspend--;
return 0;
}
-static int ftrace_update_code(void)
-{
- if (unlikely(ftrace_disabled) ||
- !ftrace_enabled || !ftraced_trigger)
- return 0;
-
- stop_machine(__ftrace_update_code, NULL, NULL);
-
- return 1;
-}
-
static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
{
struct ftrace_page *pg;
pg = ftrace_pages = ftrace_pages_start;
cnt = num_to_init / ENTRIES_PER_PAGE;
- pr_info("ftrace: allocating %ld hash entries in %d pages\n",
+ pr_info("ftrace: allocating %ld entries in %d pages\n",
num_to_init, cnt);
for (i = 0; i < cnt; i++) {
((iter->flags & FTRACE_ITER_FAILURES) &&
!(rec->flags & FTRACE_FL_FAILED)) ||
+ ((iter->flags & FTRACE_ITER_FILTER) &&
+ !(rec->flags & FTRACE_FL_FILTER)) ||
+
((iter->flags & FTRACE_ITER_NOTRACE) &&
!(rec->flags & FTRACE_FL_NOTRACE))) {
rec = NULL;
}
mutex_lock(&ftrace_sysctl_lock);
- mutex_lock(&ftraced_lock);
- if (iter->filtered && ftraced_suspend && ftrace_enabled)
+ mutex_lock(&ftrace_start_lock);
+ if (ftrace_start && ftrace_enabled)
ftrace_run_update_code(FTRACE_ENABLE_CALLS);
- mutex_unlock(&ftraced_lock);
+ mutex_unlock(&ftrace_start_lock);
mutex_unlock(&ftrace_sysctl_lock);
kfree(iter);
return ftrace_regex_release(inode, file, 0);
}
-static ssize_t
-ftraced_read(struct file *filp, char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- /* don't worry about races */
- char *buf = ftraced_stop ? "disabled\n" : "enabled\n";
- int r = strlen(buf);
-
- return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
-}
-
-static ssize_t
-ftraced_write(struct file *filp, const char __user *ubuf,
- size_t cnt, loff_t *ppos)
-{
- char buf[64];
- long val;
- int ret;
-
- if (cnt >= sizeof(buf))
- return -EINVAL;
-
- if (copy_from_user(&buf, ubuf, cnt))
- return -EFAULT;
-
- if (strncmp(buf, "enable", 6) == 0)
- val = 1;
- else if (strncmp(buf, "disable", 7) == 0)
- val = 0;
- else {
- buf[cnt] = 0;
-
- ret = strict_strtoul(buf, 10, &val);
- if (ret < 0)
- return ret;
-
- val = !!val;
- }
-
- if (val)
- ftrace_enable_daemon();
- else
- ftrace_disable_daemon();
-
- filp->f_pos += cnt;
-
- return cnt;
-}
-
static struct file_operations ftrace_avail_fops = {
.open = ftrace_avail_open,
.read = seq_read,
.release = ftrace_notrace_release,
};
-static struct file_operations ftraced_fops = {
- .open = tracing_open_generic,
- .read = ftraced_read,
- .write = ftraced_write,
-};
-
-/**
- * ftrace_force_update - force an update to all recording ftrace functions
- */
-int ftrace_force_update(void)
-{
- int ret = 0;
-
- if (unlikely(ftrace_disabled))
- return -ENODEV;
-
- mutex_lock(&ftrace_sysctl_lock);
- mutex_lock(&ftraced_lock);
-
- /*
- * If ftraced_trigger is not set, then there is nothing
- * to update.
- */
- if (ftraced_trigger && !ftrace_update_code())
- ret = -EBUSY;
-
- mutex_unlock(&ftraced_lock);
- mutex_unlock(&ftrace_sysctl_lock);
-
- return ret;
-}
-
-static void ftrace_force_shutdown(void)
-{
- struct task_struct *task;
- int command = FTRACE_DISABLE_CALLS | FTRACE_UPDATE_TRACE_FUNC;
-
- mutex_lock(&ftraced_lock);
- task = ftraced_task;
- ftraced_task = NULL;
- ftraced_suspend = -1;
- ftrace_run_update_code(command);
- mutex_unlock(&ftraced_lock);
-
- if (task)
- kthread_stop(task);
-}
-
static __init int ftrace_init_debugfs(void)
{
struct dentry *d_tracer;
pr_warning("Could not create debugfs "
"'set_ftrace_notrace' entry\n");
- entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer,
- NULL, &ftraced_fops);
- if (!entry)
- pr_warning("Could not create debugfs "
- "'ftraced_enabled' entry\n");
return 0;
}
fs_initcall(ftrace_init_debugfs);
-#ifdef CONFIG_FTRACE_MCOUNT_RECORD
static int ftrace_convert_nops(unsigned long *start,
unsigned long *end)
{
unsigned long addr;
unsigned long flags;
+ mutex_lock(&ftrace_start_lock);
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 */
+ /* disable interrupts to prevent kstop machine */
local_irq_save(flags);
- __ftrace_update_code(p);
+ ftrace_update_code();
local_irq_restore(flags);
+ mutex_unlock(&ftrace_start_lock);
return 0;
}
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;
-}
+#else
-static int __init ftrace_dynamic_init(void)
+static int __init ftrace_nodyn_init(void)
{
- struct task_struct *p;
- unsigned long addr;
- int ret;
-
- addr = (unsigned long)ftrace_record_ip;
-
- stop_machine(ftrace_dyn_arch_init, &addr, NULL);
-
- /* ftrace_dyn_arch_init places the return code in addr */
- if (addr) {
- ret = (int)addr;
- goto failed;
- }
-
- ret = ftrace_dyn_table_alloc(NR_TO_INIT);
- if (ret)
- goto failed;
-
- p = kthread_run(ftraced, NULL, "ftraced");
- if (IS_ERR(p)) {
- ret = -1;
- goto failed;
- }
-
- last_ftrace_enabled = ftrace_enabled = 1;
- ftraced_task = p;
-
+ ftrace_enabled = 1;
return 0;
-
- failed:
- ftrace_disabled = 1;
- return ret;
}
+device_initcall(ftrace_nodyn_init);
-core_initcall(ftrace_dynamic_init);
-#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
-
-#else
# define ftrace_startup() do { } while (0)
# define ftrace_shutdown() do { } while (0)
# define ftrace_startup_sysctl() do { } while (0)
# define ftrace_shutdown_sysctl() do { } while (0)
-# define ftrace_force_shutdown() do { } while (0)
#endif /* CONFIG_DYNAMIC_FTRACE */
/**
- * ftrace_kill_atomic - kill ftrace from critical sections
+ * ftrace_kill - kill ftrace
*
* 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
- * wrong, calling this function will keep ftrace from doing
- * any more modifications, and updates.
- * used when something went wrong.
- */
void ftrace_kill(void)
{
- mutex_lock(&ftrace_sysctl_lock);
ftrace_disabled = 1;
ftrace_enabled = 0;
-
clear_ftrace_function();
- mutex_unlock(&ftrace_sysctl_lock);
-
- /* Try to totally disable ftrace */
- ftrace_force_shutdown();
}
/**
mutex_unlock(&ftrace_sysctl_lock);
return ret;
}
+
projects / linux-2.6-omap-h63xx.git / blobdiff