Messages in this thread | | | Date | Mon, 12 Mar 2018 22:42:22 +0900 | From | Masami Hiramatsu <> | Subject | Re: [PATCH 2/3] tracing: Clean up and document pred_funcs_##type creation and use |
| |
On Fri, 09 Mar 2018 21:34:44 -0500 Steven Rostedt <rostedt@goodmis.org> wrote:
> From: "Steven Rostedt (VMware)" <rostedt@goodmis.org> > > The pred_funcs_##type arrays consist of five functions that are assigned > based on the ops. The array must be in the same order of the ops each > function represents. The PRED_FUNC_START macro denotes the op enum that > starts the op that maps to the pred_funcs_##type arrays. This is all very > subtle and prone to bugs if the code is changed. > > Add comments describing how PRED_FUNC_START and pred_funcs_##type array is > used, and also a PRED_FUNC_MAX that is the maximum number of functions in > the arrays. > > Clean up select_comparison_fn() that assigns the predicates to the > pred_funcs_##type array function as well as add protection in case an op is > passed in that does not map correctly to the array. >
This looks good to me.
Reviewed-by: Masami Hiramatsu <mhiramat@kernel.org>
Thanks,
> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> > --- > kernel/trace/trace_events_filter.c | 46 ++++++++++++++++++++++++++------------ > 1 file changed, 32 insertions(+), 14 deletions(-) > > diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c > index a2ef393b3bb2..9d383f4383dc 100644 > --- a/kernel/trace/trace_events_filter.c > +++ b/kernel/trace/trace_events_filter.c > @@ -65,6 +65,13 @@ struct filter_op { > > static struct filter_op filter_ops[] = { OPS }; > > +/* > + * pred functions are OP_LT, OP_LE, OP_GT, OP_GE, and OP_BAND > + * pred_funcs_##type below must match the order of them above. > + */ > +#define PRED_FUNC_START OP_LT > +#define PRED_FUNC_MAX (OP_BAND - PRED_FUNC_START) > + > #define ERRORS \ > C( NONE, "No error"), \ > C( INVALID_OP, "Invalid operator"), \ > @@ -172,8 +179,6 @@ static const filter_pred_fn_t pred_funcs_##type[] = { \ > filter_pred_BAND_##type, \ > }; > > -#define PRED_FUNC_START OP_LT > - > #define DEFINE_EQUALITY_PRED(size) \ > static int filter_pred_##size(struct filter_pred *pred, void *event) \ > { \ > @@ -946,39 +951,52 @@ static filter_pred_fn_t select_comparison_fn(enum filter_op_ids op, > int field_size, int field_is_signed) > { > filter_pred_fn_t fn = NULL; > + int pred_func_index = -1; > + > + switch (op) { > + case OP_EQ: > + case OP_NE: > + break; > + default: > + if (WARN_ON_ONCE(op < PRED_FUNC_START)) > + return NULL; > + pred_func_index = op - PRED_FUNC_START; > + if (WARN_ON_ONCE(pred_func_index > PRED_FUNC_MAX)) > + return NULL; > + } > > switch (field_size) { > case 8: > - if (op == OP_EQ || op == OP_NE) > + if (pred_func_index < 0) > fn = filter_pred_64; > else if (field_is_signed) > - fn = pred_funcs_s64[op - PRED_FUNC_START]; > + fn = pred_funcs_s64[pred_func_index]; > else > - fn = pred_funcs_u64[op - PRED_FUNC_START]; > + fn = pred_funcs_u64[pred_func_index]; > break; > case 4: > - if (op == OP_EQ || op == OP_NE) > + if (pred_func_index < 0) > fn = filter_pred_32; > else if (field_is_signed) > - fn = pred_funcs_s32[op - PRED_FUNC_START]; > + fn = pred_funcs_s32[pred_func_index]; > else > - fn = pred_funcs_u32[op - PRED_FUNC_START]; > + fn = pred_funcs_u32[pred_func_index]; > break; > case 2: > - if (op == OP_EQ || op == OP_NE) > + if (pred_func_index < 0) > fn = filter_pred_16; > else if (field_is_signed) > - fn = pred_funcs_s16[op - PRED_FUNC_START]; > + fn = pred_funcs_s16[pred_func_index]; > else > - fn = pred_funcs_u16[op - PRED_FUNC_START]; > + fn = pred_funcs_u16[pred_func_index]; > break; > case 1: > - if (op == OP_EQ || op == OP_NE) > + if (pred_func_index < 0) > fn = filter_pred_8; > else if (field_is_signed) > - fn = pred_funcs_s8[op - PRED_FUNC_START]; > + fn = pred_funcs_s8[pred_func_index]; > else > - fn = pred_funcs_u8[op - PRED_FUNC_START]; > + fn = pred_funcs_u8[pred_func_index]; > break; > } > > -- > 2.15.1 > >
-- Masami Hiramatsu <mhiramat@kernel.org>
| |