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Diffstat (limited to 'kernel/trace/trace.c')
-rw-r--r--kernel/trace/trace.c57
1 files changed, 37 insertions, 20 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index a0174a40c56..1ce5dc6372b 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -30,6 +30,7 @@
#include <linux/percpu.h>
#include <linux/splice.h>
#include <linux/kdebug.h>
+#include <linux/string.h>
#include <linux/ctype.h>
#include <linux/init.h>
#include <linux/poll.h>
@@ -147,8 +148,7 @@ static int __init set_ftrace_dump_on_oops(char *str)
}
__setup("ftrace_dump_on_oops", set_ftrace_dump_on_oops);
-long
-ns2usecs(cycle_t nsec)
+unsigned long long ns2usecs(cycle_t nsec)
{
nsec += 500;
do_div(nsec, 1000);
@@ -1632,7 +1632,11 @@ static void test_cpu_buff_start(struct trace_iterator *iter)
return;
cpumask_set_cpu(iter->cpu, iter->started);
- trace_seq_printf(s, "##### CPU %u buffer started ####\n", iter->cpu);
+
+ /* Don't print started cpu buffer for the first entry of the trace */
+ if (iter->idx > 1)
+ trace_seq_printf(s, "##### CPU %u buffer started ####\n",
+ iter->cpu);
}
static enum print_line_t print_trace_fmt(struct trace_iterator *iter)
@@ -1867,6 +1871,11 @@ __tracing_open(struct inode *inode, struct file *file)
if (current_trace)
*iter->trace = *current_trace;
+ if (!alloc_cpumask_var(&iter->started, GFP_KERNEL))
+ goto fail;
+
+ cpumask_clear(iter->started);
+
if (current_trace && current_trace->print_max)
iter->tr = &max_tr;
else
@@ -1917,6 +1926,7 @@ __tracing_open(struct inode *inode, struct file *file)
if (iter->buffer_iter[cpu])
ring_buffer_read_finish(iter->buffer_iter[cpu]);
}
+ free_cpumask_var(iter->started);
fail:
mutex_unlock(&trace_types_lock);
kfree(iter->trace);
@@ -1960,6 +1970,7 @@ static int tracing_release(struct inode *inode, struct file *file)
seq_release(inode, file);
mutex_destroy(&iter->mutex);
+ free_cpumask_var(iter->started);
kfree(iter->trace);
kfree(iter);
return 0;
@@ -2358,9 +2369,9 @@ static const char readme_msg[] =
"# mkdir /debug\n"
"# mount -t debugfs nodev /debug\n\n"
"# cat /debug/tracing/available_tracers\n"
- "wakeup preemptirqsoff preemptoff irqsoff ftrace sched_switch none\n\n"
+ "wakeup preemptirqsoff preemptoff irqsoff function sched_switch nop\n\n"
"# cat /debug/tracing/current_tracer\n"
- "none\n"
+ "nop\n"
"# echo sched_switch > /debug/tracing/current_tracer\n"
"# cat /debug/tracing/current_tracer\n"
"sched_switch\n"
@@ -3266,19 +3277,13 @@ static int tracing_buffers_open(struct inode *inode, struct file *filp)
info->tr = &global_trace;
info->cpu = cpu;
- info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
+ info->spare = NULL;
/* Force reading ring buffer for first read */
info->read = (unsigned int)-1;
- if (!info->spare)
- goto out;
filp->private_data = info;
- return 0;
-
- out:
- kfree(info);
- return -ENOMEM;
+ return nonseekable_open(inode, filp);
}
static ssize_t
@@ -3293,6 +3298,11 @@ tracing_buffers_read(struct file *filp, char __user *ubuf,
if (!count)
return 0;
+ if (!info->spare)
+ info->spare = ring_buffer_alloc_read_page(info->tr->buffer);
+ if (!info->spare)
+ return -ENOMEM;
+
/* Do we have previous read data to read? */
if (info->read < PAGE_SIZE)
goto read;
@@ -3331,7 +3341,8 @@ static int tracing_buffers_release(struct inode *inode, struct file *file)
{
struct ftrace_buffer_info *info = file->private_data;
- ring_buffer_free_read_page(info->tr->buffer, info->spare);
+ if (info->spare)
+ ring_buffer_free_read_page(info->tr->buffer, info->spare);
kfree(info);
return 0;
@@ -3417,14 +3428,19 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
int size, i;
size_t ret;
- /*
- * We can't seek on a buffer input
- */
- if (unlikely(*ppos))
- return -ESPIPE;
+ if (*ppos & (PAGE_SIZE - 1)) {
+ WARN_ONCE(1, "Ftrace: previous read must page-align\n");
+ return -EINVAL;
+ }
+ if (len & (PAGE_SIZE - 1)) {
+ WARN_ONCE(1, "Ftrace: splice_read should page-align\n");
+ if (len < PAGE_SIZE)
+ return -EINVAL;
+ len &= PAGE_MASK;
+ }
- for (i = 0; i < PIPE_BUFFERS && len; i++, len -= size) {
+ for (i = 0; i < PIPE_BUFFERS && len; i++, len -= PAGE_SIZE) {
struct page *page;
int r;
@@ -3463,6 +3479,7 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos,
spd.partial[i].offset = 0;
spd.partial[i].private = (unsigned long)ref;
spd.nr_pages++;
+ *ppos += PAGE_SIZE;
}
spd.nr_pages = i;