From 107bad8bef5ab2c3a3bff7648c18c9dc3abdc13b Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Mon, 12 May 2008 21:21:01 +0200 Subject: 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: Steven Rostedt Signed-off-by: Ingo Molnar Signed-off-by: Thomas Gleixner --- kernel/trace/trace.c | 38 +++++++++++++++++++++++++++++++------- kernel/trace/trace.h | 5 +++++ 2 files changed, 36 insertions(+), 7 deletions(-) (limited to 'kernel/trace') diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index b9126ef46a9e..32f9106d612c 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2307,11 +2307,15 @@ static int tracing_open_pipe(struct inode *inode, struct file *filp) if (!iter) return -ENOMEM; + mutex_lock(&trace_types_lock); iter->tr = &global_trace; iter->trace = current_trace; - filp->private_data = iter; + if (iter->trace->pipe_open) + iter->trace->pipe_open(iter); + mutex_unlock(&trace_types_lock); + return 0; } @@ -2380,13 +2384,24 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, 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); start = 0; while (trace_empty(iter)) { - if ((filp->f_flags & O_NONBLOCK)) - return -EAGAIN; + if ((filp->f_flags & O_NONBLOCK)) { + read = -EAGAIN; + goto out; + } /* * 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, set_current_state(TASK_INTERRUPTIBLE); iter->tr->waiter = current; + mutex_unlock(&trace_types_lock); + /* sleep for one second, and try again. */ schedule_timeout(HZ); + mutex_lock(&trace_types_lock); + iter->tr->waiter = NULL; - if (signal_pending(current)) - return -EINTR; + if (signal_pending(current)) { + read = -EINTR; + goto out; + } if (iter->trace != current_trace) - return 0; + goto out; /* * We block until we read something and tracing is disabled. @@ -2428,7 +2449,7 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, /* stop when tracing is finished */ if (trace_empty(iter)) - return 0; + goto out; if (cnt >= PAGE_SIZE) cnt = PAGE_SIZE - 1; @@ -2518,6 +2539,9 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, if (ret) read = -EFAULT; +out: + mutex_unlock(&trace_types_lock); + return read; } diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index c1ec134ac356..ee53d706066f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -135,9 +135,13 @@ struct tracer { void (*init)(struct trace_array *tr); void (*reset)(struct trace_array *tr); void (*open)(struct trace_iterator *iter); + void (*pipe_open)(struct trace_iterator *iter); void (*close)(struct trace_iterator *iter); void (*start)(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); #ifdef CONFIG_FTRACE_STARTUP_TEST int (*selftest)(struct tracer *trace, @@ -160,6 +164,7 @@ struct trace_seq { struct trace_iterator { struct trace_array *tr; struct tracer *trace; + void *private; long last_overrun[NR_CPUS]; long overrun[NR_CPUS]; -- cgit v1.2.1