unsigned long irq_flags;
int alloc;
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
+
alloc = sizeof(*entry) + size + 2; /* possible \n added */
local_save_flags(irq_flags);
unsigned long irq_flags;
int size = sizeof(struct bputs_entry);
+ if (unlikely(tracing_selftest_running || tracing_disabled))
+ return 0;
+
local_save_flags(irq_flags);
buffer = global_trace.trace_buffer.buffer;
event = trace_buffer_lock_reserve(buffer, TRACE_BPUTS, size,
tr->allocated_snapshot = false;
}
+/**
+ * tracing_alloc_snapshot - allocate snapshot buffer.
+ *
+ * This only allocates the snapshot buffer if it isn't already
+ * allocated - it doesn't also take a snapshot.
+ *
+ * This is meant to be used in cases where the snapshot buffer needs
+ * to be set up for events that can't sleep but need to be able to
+ * trigger a snapshot.
+ */
+int tracing_alloc_snapshot(void)
+{
+ struct trace_array *tr = &global_trace;
+ int ret;
+
+ ret = alloc_snapshot(tr);
+ WARN_ON(ret < 0);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
+
/**
* trace_snapshot_alloc - allocate and take a snapshot of the current buffer.
*
*/
void tracing_snapshot_alloc(void)
{
- struct trace_array *tr = &global_trace;
int ret;
- ret = alloc_snapshot(tr);
- if (WARN_ON(ret < 0))
+ ret = tracing_alloc_snapshot();
+ if (ret < 0)
return;
tracing_snapshot();
WARN_ONCE(1, "Snapshot feature not enabled, but internal snapshot used");
}
EXPORT_SYMBOL_GPL(tracing_snapshot);
+int tracing_alloc_snapshot(void)
+{
+ WARN_ONCE(1, "Snapshot feature not enabled, but snapshot allocation used");
+ return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(tracing_alloc_snapshot);
void tracing_snapshot_alloc(void)
{
/* Give warning */
}
EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit);
+static struct ring_buffer *temp_buffer;
+
struct ring_buffer_event *
trace_event_buffer_lock_reserve(struct ring_buffer **current_rb,
struct ftrace_event_file *ftrace_file,
int type, unsigned long len,
unsigned long flags, int pc)
{
+ struct ring_buffer_event *entry;
+
*current_rb = ftrace_file->tr->trace_buffer.buffer;
- return trace_buffer_lock_reserve(*current_rb,
+ entry = trace_buffer_lock_reserve(*current_rb,
type, len, flags, pc);
+ /*
+ * If tracing is off, but we have triggers enabled
+ * we still need to look at the event data. Use the temp_buffer
+ * to store the trace event for the tigger to use. It's recusive
+ * safe and will not be recorded anywhere.
+ */
+ if (!entry && ftrace_file->flags & FTRACE_EVENT_FL_TRIGGER_COND) {
+ *current_rb = temp_buffer;
+ entry = trace_buffer_lock_reserve(*current_rb,
+ type, len, flags, pc);
+ }
+ return entry;
}
EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve);
return count;
}
-static loff_t tracing_seek(struct file *file, loff_t offset, int origin)
+loff_t tracing_lseek(struct file *file, loff_t offset, int whence)
{
+ int ret;
+
if (file->f_mode & FMODE_READ)
- return seq_lseek(file, offset, origin);
+ ret = seq_lseek(file, offset, whence);
else
- return 0;
+ file->f_pos = ret = 0;
+
+ return ret;
}
static const struct file_operations tracing_fops = {
.open = tracing_open,
.read = seq_read,
.write = tracing_write_stub,
- .llseek = tracing_seek,
+ .llseek = tracing_lseek,
.release = tracing_release,
};
" instances\t\t- Make sub-buffers with: mkdir instances/foo\n"
"\t\t\t Remove sub-buffer with rmdir\n"
" trace_options\t\t- Set format or modify how tracing happens\n"
- "\t\t\t Disable an option by adding a suffix 'no' to the option name\n"
+ "\t\t\t Disable an option by adding a suffix 'no' to the\n"
+ "\t\t\t option name\n"
#ifdef CONFIG_DYNAMIC_FTRACE
"\n available_filter_functions - list of functions that can be filtered on\n"
- " set_ftrace_filter\t- echo function name in here to only trace these functions\n"
- " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
- " modules: Can select a group via module\n"
- " Format: :mod:<module-name>\n"
- " example: echo :mod:ext3 > set_ftrace_filter\n"
- " triggers: a command to perform when function is hit\n"
- " Format: <function>:<trigger>[:count]\n"
- " trigger: traceon, traceoff\n"
- " enable_event:<system>:<event>\n"
- " disable_event:<system>:<event>\n"
+ " set_ftrace_filter\t- echo function name in here to only trace these\n"
+ "\t\t\t functions\n"
+ "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
+ "\t modules: Can select a group via module\n"
+ "\t Format: :mod:<module-name>\n"
+ "\t example: echo :mod:ext3 > set_ftrace_filter\n"
+ "\t triggers: a command to perform when function is hit\n"
+ "\t Format: <function>:<trigger>[:count]\n"
+ "\t trigger: traceon, traceoff\n"
+ "\t\t enable_event:<system>:<event>\n"
+ "\t\t disable_event:<system>:<event>\n"
#ifdef CONFIG_STACKTRACE
- " stacktrace\n"
+ "\t\t stacktrace\n"
#endif
#ifdef CONFIG_TRACER_SNAPSHOT
- " snapshot\n"
+ "\t\t snapshot\n"
#endif
- " example: echo do_fault:traceoff > set_ftrace_filter\n"
- " echo do_trap:traceoff:3 > set_ftrace_filter\n"
- " The first one will disable tracing every time do_fault is hit\n"
- " The second will disable tracing at most 3 times when do_trap is hit\n"
- " The first time do trap is hit and it disables tracing, the counter\n"
- " will decrement to 2. If tracing is already disabled, the counter\n"
- " will not decrement. It only decrements when the trigger did work\n"
- " To remove trigger without count:\n"
- " echo '!<function>:<trigger> > set_ftrace_filter\n"
- " To remove trigger with a count:\n"
- " echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
+ "\t example: echo do_fault:traceoff > set_ftrace_filter\n"
+ "\t echo do_trap:traceoff:3 > set_ftrace_filter\n"
+ "\t The first one will disable tracing every time do_fault is hit\n"
+ "\t The second will disable tracing at most 3 times when do_trap is hit\n"
+ "\t The first time do trap is hit and it disables tracing, the\n"
+ "\t counter will decrement to 2. If tracing is already disabled,\n"
+ "\t the counter will not decrement. It only decrements when the\n"
+ "\t trigger did work\n"
+ "\t To remove trigger without count:\n"
+ "\t echo '!<function>:<trigger> > set_ftrace_filter\n"
+ "\t To remove trigger with a count:\n"
+ "\t echo '!<function>:<trigger>:0 > set_ftrace_filter\n"
" set_ftrace_notrace\t- echo function name in here to never trace.\n"
- " accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
- " modules: Can select a group via module command :mod:\n"
- " Does not accept triggers\n"
+ "\t accepts: func_full_name, *func_end, func_begin*, *func_middle*\n"
+ "\t modules: Can select a group via module command :mod:\n"
+ "\t Does not accept triggers\n"
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_TRACER
- " set_ftrace_pid\t- Write pid(s) to only function trace those pids (function)\n"
+ " set_ftrace_pid\t- Write pid(s) to only function trace those pids\n"
+ "\t\t (function)\n"
#endif
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
" set_graph_function\t- Trace the nested calls of a function (function_graph)\n"
" max_graph_depth\t- Trace a limited depth of nested calls (0 is unlimited)\n"
#endif
#ifdef CONFIG_TRACER_SNAPSHOT
- "\n snapshot\t\t- Like 'trace' but shows the content of the static snapshot buffer\n"
- "\t\t\t Read the contents for more information\n"
+ "\n snapshot\t\t- Like 'trace' but shows the content of the static\n"
+ "\t\t\t snapshot buffer. Read the contents for more\n"
+ "\t\t\t information\n"
#endif
#ifdef CONFIG_STACK_TRACER
" stack_trace\t\t- Shows the max stack trace when active\n"
" stack_max_size\t- Shows current max stack size that was traced\n"
- "\t\t\t Write into this file to reset the max size (trigger a new trace)\n"
+ "\t\t\t Write into this file to reset the max size (trigger a\n"
+ "\t\t\t new trace)\n"
#ifdef CONFIG_DYNAMIC_FTRACE
- " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace traces\n"
+ " stack_trace_filter\t- Like set_ftrace_filter but limits what stack_trace\n"
+ "\t\t\t traces\n"
#endif
#endif /* CONFIG_STACK_TRACER */
+ " 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"
+ " enable\t\t- Write 0/1 to enable/disable tracing of all <system>\n"
+ "\t\t\t events\n"
+ " filter\t\t- If set, only events passing filter are traced\n"
+ " events/<system>/<event>/\t- Directory containing control files for\n"
+ "\t\t\t <event>:\n"
+ " enable\t\t- Write 0/1 to enable/disable tracing of <event>\n"
+ " filter\t\t- If set, only events passing filter are traced\n"
+ " trigger\t\t- If set, a command to perform when event is hit\n"
+ "\t Format: <trigger>[:count][if <filter>]\n"
+ "\t trigger: traceon, traceoff\n"
+ "\t enable_event:<system>:<event>\n"
+ "\t disable_event:<system>:<event>\n"
+#ifdef CONFIG_STACKTRACE
+ "\t\t stacktrace\n"
+#endif
+#ifdef CONFIG_TRACER_SNAPSHOT
+ "\t\t snapshot\n"
+#endif
+ "\t example: echo traceoff > events/block/block_unplug/trigger\n"
+ "\t echo traceoff:3 > events/block/block_unplug/trigger\n"
+ "\t echo 'enable_event:kmem:kmalloc:3 if nr_rq > 1' > \\\n"
+ "\t events/block/block_unplug/trigger\n"
+ "\t The first disables tracing every time block_unplug is hit.\n"
+ "\t The second disables tracing the first 3 times block_unplug is hit.\n"
+ "\t The third enables the kmalloc event the first 3 times block_unplug\n"
+ "\t is hit and has value of greater than 1 for the 'nr_rq' event field.\n"
+ "\t Like function triggers, the counter is only decremented if it\n"
+ "\t enabled or disabled tracing.\n"
+ "\t To remove a trigger without a count:\n"
+ "\t echo '!<trigger> > <system>/<event>/trigger\n"
+ "\t To remove a trigger with a count:\n"
+ "\t echo '!<trigger>:0 > <system>/<event>/trigger\n"
+ "\t Filters can be ignored when removing a trigger.\n"
;
static ssize_t
return sret;
}
-static void tracing_pipe_buf_release(struct pipe_inode_info *pipe,
- struct pipe_buffer *buf)
-{
- __free_page(buf->page);
-}
-
static void tracing_spd_release_pipe(struct splice_pipe_desc *spd,
unsigned int idx)
{
.map = generic_pipe_buf_map,
.unmap = generic_pipe_buf_unmap,
.confirm = generic_pipe_buf_confirm,
- .release = tracing_pipe_buf_release,
+ .release = generic_pipe_buf_release,
.steal = generic_pipe_buf_steal,
.get = generic_pipe_buf_get,
};
.open = tracing_snapshot_open,
.read = seq_read,
.write = tracing_snapshot_write,
- .llseek = tracing_seek,
+ .llseek = tracing_lseek,
.release = tracing_snapshot_release,
};
rb_flags = trace_flags & TRACE_ITER_OVERWRITE ? RB_FL_OVERWRITE : 0;
+ buf->tr = tr;
+
buf->buffer = ring_buffer_alloc(size, rb_flags);
if (!buf->buffer)
return -ENOMEM;
raw_spin_lock_init(&global_trace.start_lock);
+ /* Used for event triggers */
+ temp_buffer = ring_buffer_alloc(PAGE_SIZE, RB_FL_OVERWRITE);
+ if (!temp_buffer)
+ goto out_free_cpumask;
+
/* TODO: make the number of buffers hot pluggable with CPUS */
if (allocate_trace_buffers(&global_trace, ring_buf_size) < 0) {
printk(KERN_ERR "tracer: failed to allocate ring buffer!\n");
WARN_ON(1);
- goto out_free_cpumask;
+ goto out_free_temp_buffer;
}
if (global_trace.buffer_disabled)
return 0;
+out_free_temp_buffer:
+ ring_buffer_free(temp_buffer);
out_free_cpumask:
free_percpu(global_trace.trace_buffer.data);
#ifdef CONFIG_TRACER_MAX_TRACE
projects / ~andy / linux / blobdiff