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ftrace: remove daemon
The ftrace daemon is complex and error prone. This patch strips it out of the code. Signed-off-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Steven Rostedt
Ingo Molnar
parent
07c4cc1cda
commit
cb7be3b2fc
@ -165,25 +165,8 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
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}
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#ifdef CONFIG_DYNAMIC_FTRACE
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#ifndef CONFIG_FTRACE_MCOUNT_RECORD
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/*
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* The hash lock is only needed when the recording of the mcount
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* callers are dynamic. That is, by the caller themselves and
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* not recorded via the compilation.
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*/
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static DEFINE_SPINLOCK(ftrace_hash_lock);
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#define ftrace_hash_lock(flags) spin_lock_irqsave(&ftrace_hash_lock, flags)
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#define ftrace_hash_unlock(flags) \
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spin_unlock_irqrestore(&ftrace_hash_lock, flags)
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static void ftrace_release_hash(unsigned long start, unsigned long end);
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#else
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/* This is protected via the ftrace_lock with MCOUNT_RECORD. */
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#define ftrace_hash_lock(flags) do { (void)(flags); } while (0)
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#define ftrace_hash_unlock(flags) do { } while(0)
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static inline void ftrace_release_hash(unsigned long start, unsigned long end)
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{
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}
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# error Dynamic ftrace depends on MCOUNT_RECORD
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#endif
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/*
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@ -194,8 +177,6 @@ static inline void ftrace_release_hash(unsigned long start, unsigned long end)
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*/
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static unsigned long mcount_addr = MCOUNT_ADDR;
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static struct task_struct *ftraced_task;
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enum {
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FTRACE_ENABLE_CALLS = (1 << 0),
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FTRACE_DISABLE_CALLS = (1 << 1),
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@ -212,7 +193,6 @@ static struct hlist_head ftrace_hash[FTRACE_HASHSIZE];
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static DEFINE_PER_CPU(int, ftrace_shutdown_disable_cpu);
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static DEFINE_MUTEX(ftraced_lock);
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static DEFINE_MUTEX(ftrace_regex_lock);
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struct ftrace_page {
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@ -230,10 +210,6 @@ struct ftrace_page {
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static struct ftrace_page *ftrace_pages_start;
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static struct ftrace_page *ftrace_pages;
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static int ftraced_trigger;
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static int ftraced_suspend;
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static int ftraced_stop;
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static int ftrace_record_suspend;
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static struct dyn_ftrace *ftrace_free_records;
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@ -398,7 +374,6 @@ static void
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ftrace_record_ip(unsigned long ip)
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{
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struct dyn_ftrace *node;
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unsigned long flags;
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unsigned long key;
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int resched;
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int cpu;
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@ -430,24 +405,18 @@ ftrace_record_ip(unsigned long ip)
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if (ftrace_ip_in_hash(ip, key))
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goto out;
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ftrace_hash_lock(flags);
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/* This ip may have hit the hash before the lock */
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if (ftrace_ip_in_hash(ip, key))
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goto out_unlock;
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goto out;
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node = ftrace_alloc_dyn_node(ip);
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if (!node)
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goto out_unlock;
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goto out;
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node->ip = ip;
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ftrace_add_hash(node, key);
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ftraced_trigger = 1;
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out_unlock:
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ftrace_hash_unlock(flags);
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out:
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per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
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@ -647,7 +616,7 @@ ftrace_code_disable(struct dyn_ftrace *rec)
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return 1;
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}
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static int __ftrace_update_code(void *ignore);
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static int ftrace_update_code(void *ignore);
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static int __ftrace_modify_code(void *data)
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{
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@ -659,7 +628,7 @@ static int __ftrace_modify_code(void *data)
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* Update any recorded ips now that we have the
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* machine stopped
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*/
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__ftrace_update_code(NULL);
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ftrace_update_code(NULL);
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ftrace_replace_code(1);
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tracing_on = 1;
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} else if (*command & FTRACE_DISABLE_CALLS) {
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@ -686,26 +655,9 @@ static void ftrace_run_update_code(int command)
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stop_machine(__ftrace_modify_code, &command, NULL);
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}
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void ftrace_disable_daemon(void)
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{
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/* Stop the daemon from calling kstop_machine */
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mutex_lock(&ftraced_lock);
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ftraced_stop = 1;
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mutex_unlock(&ftraced_lock);
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ftrace_force_update();
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}
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void ftrace_enable_daemon(void)
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{
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mutex_lock(&ftraced_lock);
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ftraced_stop = 0;
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mutex_unlock(&ftraced_lock);
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ftrace_force_update();
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}
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static ftrace_func_t saved_ftrace_func;
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static int ftrace_start;
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static DEFINE_MUTEX(ftrace_start_lock);
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static void ftrace_startup(void)
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{
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@ -714,9 +666,9 @@ static void ftrace_startup(void)
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if (unlikely(ftrace_disabled))
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return;
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mutex_lock(&ftraced_lock);
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ftraced_suspend++;
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if (ftraced_suspend == 1)
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mutex_lock(&ftrace_start_lock);
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ftrace_start++;
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if (ftrace_start == 1)
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command |= FTRACE_ENABLE_CALLS;
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if (saved_ftrace_func != ftrace_trace_function) {
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@ -729,7 +681,7 @@ static void ftrace_startup(void)
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ftrace_run_update_code(command);
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out:
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_start_lock);
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}
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static void ftrace_shutdown(void)
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@ -739,9 +691,9 @@ static void ftrace_shutdown(void)
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if (unlikely(ftrace_disabled))
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return;
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mutex_lock(&ftraced_lock);
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ftraced_suspend--;
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if (!ftraced_suspend)
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mutex_lock(&ftrace_start_lock);
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ftrace_start--;
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if (!ftrace_start)
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command |= FTRACE_DISABLE_CALLS;
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if (saved_ftrace_func != ftrace_trace_function) {
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@ -754,7 +706,7 @@ static void ftrace_shutdown(void)
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ftrace_run_update_code(command);
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out:
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_start_lock);
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}
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static void ftrace_startup_sysctl(void)
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@ -764,15 +716,15 @@ static void ftrace_startup_sysctl(void)
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if (unlikely(ftrace_disabled))
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return;
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mutex_lock(&ftraced_lock);
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mutex_lock(&ftrace_start_lock);
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/* Force update next time */
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saved_ftrace_func = NULL;
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/* ftraced_suspend is true if we want ftrace running */
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if (ftraced_suspend)
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/* ftrace_start is true if we want ftrace running */
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if (ftrace_start)
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command |= FTRACE_ENABLE_CALLS;
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ftrace_run_update_code(command);
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_start_lock);
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}
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static void ftrace_shutdown_sysctl(void)
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@ -782,20 +734,20 @@ static void ftrace_shutdown_sysctl(void)
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if (unlikely(ftrace_disabled))
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return;
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mutex_lock(&ftraced_lock);
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/* ftraced_suspend is true if ftrace is running */
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if (ftraced_suspend)
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mutex_lock(&ftrace_start_lock);
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/* ftrace_start is true if ftrace is running */
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if (ftrace_start)
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command |= FTRACE_DISABLE_CALLS;
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ftrace_run_update_code(command);
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_start_lock);
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}
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static cycle_t ftrace_update_time;
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static unsigned long ftrace_update_cnt;
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unsigned long ftrace_update_tot_cnt;
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static int __ftrace_update_code(void *ignore)
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static int ftrace_update_code(void *ignore)
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{
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int i, save_ftrace_enabled;
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cycle_t start, stop;
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@ -869,7 +821,6 @@ static int __ftrace_update_code(void *ignore)
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stop = ftrace_now(raw_smp_processor_id());
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ftrace_update_time = stop - start;
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ftrace_update_tot_cnt += ftrace_update_cnt;
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ftraced_trigger = 0;
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ftrace_enabled = save_ftrace_enabled;
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ftrace_record_suspend--;
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@ -877,17 +828,6 @@ static int __ftrace_update_code(void *ignore)
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return 0;
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}
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static int ftrace_update_code(void)
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{
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if (unlikely(ftrace_disabled) ||
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!ftrace_enabled || !ftraced_trigger)
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return 0;
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stop_machine(__ftrace_update_code, NULL, NULL);
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return 1;
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}
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static int __init ftrace_dyn_table_alloc(unsigned long num_to_init)
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{
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struct ftrace_page *pg;
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@ -1425,10 +1365,10 @@ ftrace_regex_release(struct inode *inode, struct file *file, int enable)
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}
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mutex_lock(&ftrace_sysctl_lock);
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mutex_lock(&ftraced_lock);
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if (iter->filtered && ftraced_suspend && ftrace_enabled)
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mutex_lock(&ftrace_start_lock);
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if (iter->filtered && ftrace_start && ftrace_enabled)
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ftrace_run_update_code(FTRACE_ENABLE_CALLS);
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_start_lock);
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mutex_unlock(&ftrace_sysctl_lock);
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kfree(iter);
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@ -1448,55 +1388,6 @@ ftrace_notrace_release(struct inode *inode, struct file *file)
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return ftrace_regex_release(inode, file, 0);
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}
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static ssize_t
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ftraced_read(struct file *filp, char __user *ubuf,
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size_t cnt, loff_t *ppos)
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{
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/* don't worry about races */
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char *buf = ftraced_stop ? "disabled\n" : "enabled\n";
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int r = strlen(buf);
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return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
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}
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static ssize_t
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ftraced_write(struct file *filp, const char __user *ubuf,
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size_t cnt, loff_t *ppos)
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{
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char buf[64];
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long val;
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int ret;
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if (cnt >= sizeof(buf))
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return -EINVAL;
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if (copy_from_user(&buf, ubuf, cnt))
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return -EFAULT;
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if (strncmp(buf, "enable", 6) == 0)
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val = 1;
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else if (strncmp(buf, "disable", 7) == 0)
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val = 0;
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else {
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buf[cnt] = 0;
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ret = strict_strtoul(buf, 10, &val);
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if (ret < 0)
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return ret;
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val = !!val;
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}
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if (val)
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ftrace_enable_daemon();
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else
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ftrace_disable_daemon();
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filp->f_pos += cnt;
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return cnt;
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}
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static struct file_operations ftrace_avail_fops = {
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.open = ftrace_avail_open,
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.read = seq_read,
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@ -1527,38 +1418,6 @@ static struct file_operations ftrace_notrace_fops = {
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.release = ftrace_notrace_release,
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};
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static struct file_operations ftraced_fops = {
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.open = tracing_open_generic,
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.read = ftraced_read,
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.write = ftraced_write,
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};
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/**
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* ftrace_force_update - force an update to all recording ftrace functions
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*/
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int ftrace_force_update(void)
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{
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int ret = 0;
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if (unlikely(ftrace_disabled))
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return -ENODEV;
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mutex_lock(&ftrace_sysctl_lock);
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mutex_lock(&ftraced_lock);
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/*
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* If ftraced_trigger is not set, then there is nothing
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* to update.
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*/
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if (ftraced_trigger && !ftrace_update_code())
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ret = -EBUSY;
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_sysctl_lock);
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return ret;
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}
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static __init int ftrace_init_debugfs(void)
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{
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struct dentry *d_tracer;
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@ -1589,17 +1448,11 @@ static __init int ftrace_init_debugfs(void)
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pr_warning("Could not create debugfs "
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"'set_ftrace_notrace' entry\n");
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entry = debugfs_create_file("ftraced_enabled", 0644, d_tracer,
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NULL, &ftraced_fops);
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if (!entry)
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pr_warning("Could not create debugfs "
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"'ftraced_enabled' entry\n");
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return 0;
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}
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fs_initcall(ftrace_init_debugfs);
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#ifdef CONFIG_FTRACE_MCOUNT_RECORD
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static int ftrace_convert_nops(unsigned long *start,
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unsigned long *end)
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{
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@ -1619,7 +1472,7 @@ static int ftrace_convert_nops(unsigned long *start,
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/* p is ignored */
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local_irq_save(flags);
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__ftrace_update_code(p);
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ftrace_update_code(p);
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local_irq_restore(flags);
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return 0;
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@ -1666,122 +1519,6 @@ void __init ftrace_init(void)
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failed:
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ftrace_disabled = 1;
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}
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#else /* CONFIG_FTRACE_MCOUNT_RECORD */
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static void ftrace_release_hash(unsigned long start, unsigned long end)
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{
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struct dyn_ftrace *rec;
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struct hlist_node *t, *n;
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struct hlist_head *head, temp_list;
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unsigned long flags;
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int i, cpu;
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preempt_disable_notrace();
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/* disable incase we call something that calls mcount */
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cpu = raw_smp_processor_id();
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per_cpu(ftrace_shutdown_disable_cpu, cpu)++;
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ftrace_hash_lock(flags);
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for (i = 0; i < FTRACE_HASHSIZE; i++) {
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INIT_HLIST_HEAD(&temp_list);
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head = &ftrace_hash[i];
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/* all CPUS are stopped, we are safe to modify code */
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hlist_for_each_entry_safe(rec, t, n, head, node) {
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if (rec->flags & FTRACE_FL_FREE)
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continue;
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if ((rec->ip >= start) && (rec->ip < end))
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ftrace_free_rec(rec);
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}
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}
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ftrace_hash_unlock(flags);
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per_cpu(ftrace_shutdown_disable_cpu, cpu)--;
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preempt_enable_notrace();
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}
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static int ftraced(void *ignore)
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{
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unsigned long usecs;
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while (!kthread_should_stop()) {
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set_current_state(TASK_INTERRUPTIBLE);
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/* check once a second */
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schedule_timeout(HZ);
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if (unlikely(ftrace_disabled))
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continue;
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mutex_lock(&ftrace_sysctl_lock);
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mutex_lock(&ftraced_lock);
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if (!ftraced_suspend && !ftraced_stop &&
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ftrace_update_code()) {
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usecs = nsecs_to_usecs(ftrace_update_time);
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if (ftrace_update_tot_cnt > 100000) {
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ftrace_update_tot_cnt = 0;
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pr_info("hm, dftrace overflow: %lu change%s"
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" (%lu total) in %lu usec%s\n",
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ftrace_update_cnt,
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ftrace_update_cnt != 1 ? "s" : "",
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ftrace_update_tot_cnt,
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usecs, usecs != 1 ? "s" : "");
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FTRACE_WARN_ON_ONCE(1);
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}
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}
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mutex_unlock(&ftraced_lock);
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mutex_unlock(&ftrace_sysctl_lock);
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ftrace_shutdown_replenish();
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}
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__set_current_state(TASK_RUNNING);
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return 0;
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}
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static int __init ftrace_dynamic_init(void)
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{
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struct task_struct *p;
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unsigned long addr;
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int ret;
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addr = (unsigned long)ftrace_record_ip;
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stop_machine(ftrace_dyn_arch_init, &addr, NULL);
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/* ftrace_dyn_arch_init places the return code in addr */
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if (addr) {
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ret = (int)addr;
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goto failed;
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}
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ret = ftrace_dyn_table_alloc(NR_TO_INIT);
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if (ret)
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goto failed;
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|
||||
p = kthread_run(ftraced, NULL, "ftraced");
|
||||
if (IS_ERR(p)) {
|
||||
ret = -1;
|
||||
goto failed;
|
||||
}
|
||||
|
||||
last_ftrace_enabled = ftrace_enabled = 1;
|
||||
ftraced_task = p;
|
||||
|
||||
return 0;
|
||||
|
||||
failed:
|
||||
ftrace_disabled = 1;
|
||||
return ret;
|
||||
}
|
||||
|
||||
core_initcall(ftrace_dynamic_init);
|
||||
#endif /* CONFIG_FTRACE_MCOUNT_RECORD */
|
||||
|
||||
#else
|
||||
# define ftrace_startup() do { } while (0)
|
||||
@ -1801,9 +1538,6 @@ void ftrace_kill(void)
|
||||
{
|
||||
ftrace_disabled = 1;
|
||||
ftrace_enabled = 0;
|
||||
#ifdef CONFIG_DYNAMIC_FTRACE
|
||||
ftraced_suspend = -1;
|
||||
#endif
|
||||
clear_ftrace_function();
|
||||
}
|
||||
|
||||
|
||||
@ -99,13 +99,6 @@ int trace_selftest_startup_dynamic_tracing(struct tracer *trace,
|
||||
/* passed in by parameter to fool gcc from optimizing */
|
||||
func();
|
||||
|
||||
/* update the records */
|
||||
ret = ftrace_force_update();
|
||||
if (ret) {
|
||||
printk(KERN_CONT ".. ftraced failed .. ");
|
||||
return ret;
|
||||
}
|
||||
|
||||
/*
|
||||
* Some archs *cough*PowerPC*cough* add charachters to the
|
||||
* start of the function names. We simply put a '*' to
|
||||
@ -183,13 +176,6 @@ trace_selftest_startup_function(struct tracer *trace, struct trace_array *tr)
|
||||
/* make sure msleep has been recorded */
|
||||
msleep(1);
|
||||
|
||||
/* force the recorded functions to be traced */
|
||||
ret = ftrace_force_update();
|
||||
if (ret) {
|
||||
printk(KERN_CONT ".. ftraced failed .. ");
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* start the tracing */
|
||||
ftrace_enabled = 1;
|
||||
tracer_enabled = 1;
|
||||
|
||||
Loading…
Reference in New Issue
Block a user