Commit 107bad8b authored by Steven Rostedt's avatar Steven Rostedt Committed by Thomas Gleixner

ftrace: add trace pipe header pluggin

This patch adds a method for open_pipe and open_read to the pluggins
so that they can add a header to the trace pipe call.
Signed-off-by: default avatarSteven Rostedt <srostedt@redhat.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 53d0aa77
...@@ -2307,11 +2307,15 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) ...@@ -2307,11 +2307,15 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp)
if (!iter) if (!iter)
return -ENOMEM; return -ENOMEM;
mutex_lock(&trace_types_lock);
iter->tr = &global_trace; iter->tr = &global_trace;
iter->trace = current_trace; iter->trace = current_trace;
filp->private_data = iter; filp->private_data = iter;
if (iter->trace->pipe_open)
iter->trace->pipe_open(iter);
mutex_unlock(&trace_types_lock);
return 0; return 0;
} }
...@@ -2380,13 +2384,24 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, ...@@ -2380,13 +2384,24 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
return cnt; return cnt;
} }
mutex_lock(&trace_types_lock);
if (iter->trace->read) {
ret = iter->trace->read(iter, filp, ubuf, cnt, ppos);
if (ret) {
read = ret;
goto out;
}
}
trace_seq_reset(&iter->seq); trace_seq_reset(&iter->seq);
start = 0; start = 0;
while (trace_empty(iter)) { while (trace_empty(iter)) {
if ((filp->f_flags & O_NONBLOCK)) if ((filp->f_flags & O_NONBLOCK)) {
return -EAGAIN; read = -EAGAIN;
goto out;
}
/* /*
* This is a make-shift waitqueue. The reason we don't use * This is a make-shift waitqueue. The reason we don't use
...@@ -2400,16 +2415,22 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, ...@@ -2400,16 +2415,22 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
set_current_state(TASK_INTERRUPTIBLE); set_current_state(TASK_INTERRUPTIBLE);
iter->tr->waiter = current; iter->tr->waiter = current;
mutex_unlock(&trace_types_lock);
/* sleep for one second, and try again. */ /* sleep for one second, and try again. */
schedule_timeout(HZ); schedule_timeout(HZ);
mutex_lock(&trace_types_lock);
iter->tr->waiter = NULL; iter->tr->waiter = NULL;
if (signal_pending(current)) if (signal_pending(current)) {
return -EINTR; read = -EINTR;
goto out;
}
if (iter->trace != current_trace) if (iter->trace != current_trace)
return 0; goto out;
/* /*
* We block until we read something and tracing is disabled. * We block until we read something and tracing is disabled.
...@@ -2428,7 +2449,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, ...@@ -2428,7 +2449,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
/* stop when tracing is finished */ /* stop when tracing is finished */
if (trace_empty(iter)) if (trace_empty(iter))
return 0; goto out;
if (cnt >= PAGE_SIZE) if (cnt >= PAGE_SIZE)
cnt = PAGE_SIZE - 1; cnt = PAGE_SIZE - 1;
...@@ -2518,6 +2539,9 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, ...@@ -2518,6 +2539,9 @@ tracing_read_pipe(struct file *filp, char __user *ubuf,
if (ret) if (ret)
read = -EFAULT; read = -EFAULT;
out:
mutex_unlock(&trace_types_lock);
return read; return read;
} }
......
...@@ -135,9 +135,13 @@ struct tracer { ...@@ -135,9 +135,13 @@ struct tracer {
void (*init)(struct trace_array *tr); void (*init)(struct trace_array *tr);
void (*reset)(struct trace_array *tr); void (*reset)(struct trace_array *tr);
void (*open)(struct trace_iterator *iter); void (*open)(struct trace_iterator *iter);
void (*pipe_open)(struct trace_iterator *iter);
void (*close)(struct trace_iterator *iter); void (*close)(struct trace_iterator *iter);
void (*start)(struct trace_iterator *iter); void (*start)(struct trace_iterator *iter);
void (*stop)(struct trace_iterator *iter); void (*stop)(struct trace_iterator *iter);
ssize_t (*read)(struct trace_iterator *iter,
struct file *filp, char __user *ubuf,
size_t cnt, loff_t *ppos);
void (*ctrl_update)(struct trace_array *tr); void (*ctrl_update)(struct trace_array *tr);
#ifdef CONFIG_FTRACE_STARTUP_TEST #ifdef CONFIG_FTRACE_STARTUP_TEST
int (*selftest)(struct tracer *trace, int (*selftest)(struct tracer *trace,
...@@ -160,6 +164,7 @@ struct trace_seq { ...@@ -160,6 +164,7 @@ struct trace_seq {
struct trace_iterator { struct trace_iterator {
struct trace_array *tr; struct trace_array *tr;
struct tracer *trace; struct tracer *trace;
void *private;
long last_overrun[NR_CPUS]; long last_overrun[NR_CPUS];
long overrun[NR_CPUS]; long overrun[NR_CPUS];
......
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