diff options
Diffstat (limited to 'kernel/trace/trace.c')
| -rw-r--r-- | kernel/trace/trace.c | 61 |
1 files changed, 44 insertions, 17 deletions
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index dade4c9559cc..8696ce6bf2f6 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1047,7 +1047,7 @@ void disable_trace_on_warning(void) * * Shows real state of the ring buffer if it is enabled or not. */ -static int tracer_tracing_is_on(struct trace_array *tr) +int tracer_tracing_is_on(struct trace_array *tr) { if (tr->trace_buffer.buffer) return ring_buffer_record_is_on(tr->trace_buffer.buffer); @@ -4123,6 +4123,30 @@ static const char readme_msg[] = "\t\t\t traces\n" #endif #endif /* CONFIG_STACK_TRACER */ +#ifdef CONFIG_KPROBE_EVENT + " kprobe_events\t\t- Add/remove/show the kernel dynamic events\n" + "\t\t\t Write into this file to define/undefine new trace events.\n" +#endif +#ifdef CONFIG_UPROBE_EVENT + " uprobe_events\t\t- Add/remove/show the userspace dynamic events\n" + "\t\t\t Write into this file to define/undefine new trace events.\n" +#endif +#if defined(CONFIG_KPROBE_EVENT) || defined(CONFIG_UPROBE_EVENT) + "\t accepts: event-definitions (one definition per line)\n" + "\t Format: p|r[:[<group>/]<event>] <place> [<args>]\n" + "\t -:[<group>/]<event>\n" +#ifdef CONFIG_KPROBE_EVENT + "\t place: [<module>:]<symbol>[+<offset>]|<memaddr>\n" +#endif +#ifdef CONFIG_UPROBE_EVENT + "\t place: <path>:<offset>\n" +#endif + "\t args: <name>=fetcharg[:type]\n" + "\t fetcharg: %<register>, @<address>, @<symbol>[+|-<offset>],\n" + "\t $stack<index>, $stack, $retval, $comm\n" + "\t type: s8/16/32/64, u8/16/32/64, x8/16/32/64, string,\n" + "\t b<bit-width>@<bit-offset>/<container-size>\n" +#endif " events/\t\t- Directory containing all trace event subsystems:\n" " enable\t\t- Write 0/1 to enable/disable tracing of all events\n" " events/<system>/\t- Directory containing all trace events for <system>:\n" @@ -4945,7 +4969,7 @@ out: return ret; } -#ifdef CONFIG_TRACER_MAX_TRACE +#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) static ssize_t tracing_max_lat_read(struct file *filp, char __user *ubuf, @@ -5124,19 +5148,20 @@ tracing_read_pipe(struct file *filp, char __user *ubuf, struct trace_iterator *iter = filp->private_data; ssize_t sret; - /* return any leftover data */ - sret = trace_seq_to_user(&iter->seq, ubuf, cnt); - if (sret != -EBUSY) - return sret; - - trace_seq_init(&iter->seq); - /* * Avoid more than one consumer on a single file descriptor * This is just a matter of traces coherency, the ring buffer itself * is protected. */ mutex_lock(&iter->mutex); + + /* return any leftover data */ + sret = trace_seq_to_user(&iter->seq, ubuf, cnt); + if (sret != -EBUSY) + goto out; + + trace_seq_init(&iter->seq); + if (iter->trace->read) { sret = iter->trace->read(iter, filp, ubuf, cnt, ppos); if (sret) @@ -5867,7 +5892,7 @@ static const struct file_operations tracing_thresh_fops = { .llseek = generic_file_llseek, }; -#ifdef CONFIG_TRACER_MAX_TRACE +#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) static const struct file_operations tracing_max_lat_fops = { .open = tracing_open_generic, .read = tracing_max_lat_read, @@ -6163,9 +6188,6 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, return -EBUSY; #endif - if (splice_grow_spd(pipe, &spd)) - return -ENOMEM; - if (*ppos & (PAGE_SIZE - 1)) return -EINVAL; @@ -6175,6 +6197,9 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, len &= PAGE_MASK; } + if (splice_grow_spd(pipe, &spd)) + return -ENOMEM; + again: trace_access_lock(iter->cpu_file); entries = ring_buffer_entries_cpu(iter->trace_buffer->buffer, iter->cpu_file); @@ -6232,19 +6257,21 @@ tracing_buffers_splice_read(struct file *file, loff_t *ppos, /* did we read anything? */ if (!spd.nr_pages) { if (ret) - return ret; + goto out; + ret = -EAGAIN; if ((file->f_flags & O_NONBLOCK) || (flags & SPLICE_F_NONBLOCK)) - return -EAGAIN; + goto out; ret = wait_on_pipe(iter, true); if (ret) - return ret; + goto out; goto again; } ret = splice_to_pipe(pipe, &spd); +out: splice_shrink_spd(&spd); return ret; @@ -7195,7 +7222,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) create_trace_options_dir(tr); -#ifdef CONFIG_TRACER_MAX_TRACE +#if defined(CONFIG_TRACER_MAX_TRACE) || defined(CONFIG_HWLAT_TRACER) trace_create_file("tracing_max_latency", 0644, d_tracer, &tr->max_latency, &tracing_max_lat_fops); #endif |