Merge branch 'devel' of... (c1e7abbc) · Commits · e / devices / android_kernel_fairphone_FP4

include/linux/ring_buffer.h

+3 −0

Original line number	Diff line number	Diff line
		@@ -120,6 +120,9 @@ unsigned long ring_buffer_overruns(struct ring_buffer *buffer);
		u64 ring_buffer_time_stamp(int cpu);
		void ring_buffer_normalize_time_stamp(int cpu, u64 *ts);

		void tracing_on(void);
		void tracing_off(void);

		enum ring_buffer_flags {
		RB_FL_OVERWRITE = 1 << 0,
		};

kernel/trace/ftrace.c

+2 −6

Original line number	Diff line number	Diff line
		@@ -185,7 +185,6 @@ enum {
		};

		static int ftrace_filtered;
		static int tracing_on;

		static LIST_HEAD(ftrace_new_addrs);

		@@ -506,13 +505,10 @@ static int __ftrace_modify_code(void *data)
		{
		int *command = data;

		if (*command & FTRACE_ENABLE_CALLS) {
		if (*command & FTRACE_ENABLE_CALLS)
		ftrace_replace_code(1);
		tracing_on = 1;
		} else if (*command & FTRACE_DISABLE_CALLS) {
		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);

kernel/trace/ring_buffer.c

+101 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,35 @@
		#include <linux/list.h>
		#include <linux/fs.h>

		#include "trace.h"

		/* Global flag to disable all recording to ring buffers */
		static int ring_buffers_off __read_mostly;

		/**
		* tracing_on - enable all tracing buffers
		*
		* This function enables all tracing buffers that may have been
		* disabled with tracing_off.
		*/
		void tracing_on(void)
		{
		ring_buffers_off = 0;
		}

		/**
		* tracing_off - turn off all tracing buffers
		*
		* This function stops all tracing buffers from recording data.
		* It does not disable any overhead the tracers themselves may
		* be causing. This function simply causes all recording to
		* the ring buffers to fail.
		*/
		void tracing_off(void)
		{
		ring_buffers_off = 1;
		}

		/* Up this if you want to test the TIME_EXTENTS and normalization */
		#define DEBUG_SHIFT 0

		@@ -1133,6 +1162,9 @@ ring_buffer_lock_reserve(struct ring_buffer *buffer,
		struct ring_buffer_event *event;
		int cpu, resched;

		if (ring_buffers_off)
		return NULL;

		if (atomic_read(&buffer->record_disabled))
		return NULL;

		@@ -1249,6 +1281,9 @@ int ring_buffer_write(struct ring_buffer *buffer,
		int ret = -EBUSY;
		int cpu, resched;

		if (ring_buffers_off)
		return -EBUSY;

		if (atomic_read(&buffer->record_disabled))
		return -EBUSY;

		@@ -2070,3 +2105,69 @@ int ring_buffer_swap_cpu(struct ring_buffer *buffer_a,
		return 0;
		}

		static ssize_t
		rb_simple_read(struct file filp, char __user ubuf,
		size_t cnt, loff_t *ppos)
		{
		int *p = filp->private_data;
		char buf[64];
		int r;

		/* !ring_buffers_off == tracing_on */
		r = sprintf(buf, "%d\n", !*p);

		return simple_read_from_buffer(ubuf, cnt, ppos, buf, r);
		}

		static ssize_t
		rb_simple_write(struct file filp, const char __user ubuf,
		size_t cnt, loff_t *ppos)
		{
		int *p = filp->private_data;
		char buf[64];
		long val;
		int ret;

		if (cnt >= sizeof(buf))
		return -EINVAL;

		if (copy_from_user(&buf, ubuf, cnt))
		return -EFAULT;

		buf[cnt] = 0;

		ret = strict_strtoul(buf, 10, &val);
		if (ret < 0)
		return ret;

		/* !ring_buffers_off == tracing_on */
		*p = !val;

		(*ppos)++;

		return cnt;
		}

		static struct file_operations rb_simple_fops = {
		.open = tracing_open_generic,
		.read = rb_simple_read,
		.write = rb_simple_write,
		};


		static __init int rb_init_debugfs(void)
		{
		struct dentry *d_tracer;
		struct dentry *entry;

		d_tracer = tracing_init_dentry();

		entry = debugfs_create_file("tracing_on", 0644, d_tracer,
		&ring_buffers_off, &rb_simple_fops);
		if (!entry)
		pr_warning("Could not create debugfs 'tracing_on' entry\n");

		return 0;
		}

		fs_initcall(rb_init_debugfs);