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| author | Steven Rostedt (Red Hat) | 2014-11-12 16:29:54 +0100 |
|---|---|---|
| committer | Steven Rostedt | 2014-11-19 21:25:39 +0100 |
| commit | 19a7fe206232cc875a3083211e0a21c08edd756e (patch) | |
| tree | 948aba93b9f2f6681eb7cc3209b0ec87e19470d1 /include | |
| parent | tracing: Fix trace_seq_bitmask() to start at current position (diff) | |
| download | kernel-qcow2-linux-19a7fe206232cc875a3083211e0a21c08edd756e.tar.gz kernel-qcow2-linux-19a7fe206232cc875a3083211e0a21c08edd756e.tar.xz kernel-qcow2-linux-19a7fe206232cc875a3083211e0a21c08edd756e.zip | |
tracing: Add trace_seq_has_overflowed() and trace_handle_return()
Adding a trace_seq_has_overflowed() which returns true if the trace_seq
had too much written into it allows us to simplify the code.
Instead of checking the return value of every call to trace_seq_printf()
and friends, they can all be called normally, and at the end we can
return !trace_seq_has_overflowed() instead.
Several functions also return TRACE_TYPE_PARTIAL_LINE when the trace_seq
overflowed and TRACE_TYPE_HANDLED otherwise. Another helper function
was created called trace_handle_return() which takes a trace_seq and
returns these enums. Using this helper function also simplifies the
code.
This change also makes it possible to remove the return values of
trace_seq_printf() and friends. They should instead just be
void functions.
Link: http://lkml.kernel.org/r/20141114011410.365183157@goodmis.org
Reviewed-by: Petr Mladek <pmladek@suse.cz>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/ftrace_event.h | 11 | ||||
| -rw-r--r-- | include/linux/trace_seq.h | 12 | ||||
| -rw-r--r-- | include/trace/ftrace.h | 6 |
3 files changed, 25 insertions, 4 deletions
diff --git a/include/linux/ftrace_event.h b/include/linux/ftrace_event.h index 28672e87e910..0bebb5c348b8 100644 --- a/include/linux/ftrace_event.h +++ b/include/linux/ftrace_event.h @@ -138,6 +138,17 @@ enum print_line_t { TRACE_TYPE_NO_CONSUME = 3 /* Handled but ask to not consume */ }; +/* + * Several functions return TRACE_TYPE_PARTIAL_LINE if the trace_seq + * overflowed, and TRACE_TYPE_HANDLED otherwise. This helper function + * simplifies those functions and keeps them in sync. + */ +static inline enum print_line_t trace_handle_return(struct trace_seq *s) +{ + return trace_seq_has_overflowed(s) ? + TRACE_TYPE_PARTIAL_LINE : TRACE_TYPE_HANDLED; +} + void tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, int pc); diff --git a/include/linux/trace_seq.h b/include/linux/trace_seq.h index ea6c9dea79e3..07eda413dfcf 100644 --- a/include/linux/trace_seq.h +++ b/include/linux/trace_seq.h @@ -40,6 +40,18 @@ trace_seq_buffer_ptr(struct trace_seq *s) return s->buffer + s->len; } +/** + * trace_seq_has_overflowed - return true if the trace_seq took too much + * @s: trace sequence descriptor + * + * Returns true if too much data was added to the trace_seq and it is + * now full and will not take anymore. + */ +static inline bool trace_seq_has_overflowed(struct trace_seq *s) +{ + return s->full || s->len > PAGE_SIZE - 1; +} + /* * Currently only defined when tracing is enabled. */ diff --git a/include/trace/ftrace.h b/include/trace/ftrace.h index 26b4f2e13275..f13471b5d27a 100644 --- a/include/trace/ftrace.h +++ b/include/trace/ftrace.h @@ -280,11 +280,9 @@ ftrace_raw_output_##call(struct trace_iterator *iter, int flags, \ if (ret) \ return ret; \ \ - ret = trace_seq_printf(s, print); \ - if (!ret) \ - return TRACE_TYPE_PARTIAL_LINE; \ + trace_seq_printf(s, print); \ \ - return TRACE_TYPE_HANDLED; \ + return trace_handle_return(s); \ } \ static struct trace_event_functions ftrace_event_type_funcs_##call = { \ .trace = ftrace_raw_output_##call, \ |