From 9f61668073a8d80650622e792aff876db9ca23c6 Mon Sep 17 00:00:00 2001 From: Daniel Wagner Date: Mon, 10 Aug 2015 14:35:46 +0200 Subject: tracing: Allow triggers to filter for CPU ids and process names By extending the filter rules by more generic fields we can write triggers filters like echo 'stacktrace if cpu == 1' > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger or echo 'stacktrace if comm == sshd' > \ /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger CPU and COMM are not part of struct trace_entry. We could add the two new fields to ftrace_common_field list and fix up all depending sides. But that looks pretty ugly. Another thing I would like to avoid that the 'format' file contents changes. All this can be avoided by introducing another list which contains non field members of struct trace_entry. Link: http://lkml.kernel.org/r/1439210146-24707-1-git-send-email-daniel.wagner@bmw-carit.de Signed-off-by: Daniel Wagner Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_filter.c | 54 ++++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 2 deletions(-) (limited to 'kernel/trace/trace_events_filter.c') diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index d81d6f302b14..bd1bf184c5c9 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -252,6 +252,50 @@ static int filter_pred_strloc(struct filter_pred *pred, void *event) return match; } +/* Filter predicate for CPUs. */ +static int filter_pred_cpu(struct filter_pred *pred, void *event) +{ + int cpu, cmp; + int match = 0; + + cpu = raw_smp_processor_id(); + cmp = pred->val; + + switch (pred->op) { + case OP_EQ: + match = cpu == cmp; + break; + case OP_LT: + match = cpu < cmp; + break; + case OP_LE: + match = cpu <= cmp; + break; + case OP_GT: + match = cpu > cmp; + break; + case OP_GE: + match = cpu >= cmp; + break; + default: + break; + } + + return !!match == !pred->not; +} + +/* Filter predicate for COMM. */ +static int filter_pred_comm(struct filter_pred *pred, void *event) +{ + int cmp, match; + + cmp = pred->regex.match(current->comm, &pred->regex, + pred->regex.field_len); + match = cmp ^ pred->not; + + return match; +} + static int filter_pred_none(struct filter_pred *pred, void *event) { return 0; @@ -1002,7 +1046,10 @@ static int init_pred(struct filter_parse_state *ps, if (is_string_field(field)) { filter_build_regex(pred); - if (field->filter_type == FILTER_STATIC_STRING) { + if (!strcmp(field->name, "comm")) { + fn = filter_pred_comm; + pred->regex.field_len = TASK_COMM_LEN; + } else if (field->filter_type == FILTER_STATIC_STRING) { fn = filter_pred_string; pred->regex.field_len = field->size; } else if (field->filter_type == FILTER_DYN_STRING) @@ -1025,7 +1072,10 @@ static int init_pred(struct filter_parse_state *ps, } pred->val = val; - fn = select_comparison_fn(pred->op, field->size, + if (!strcmp(field->name, "cpu")) + fn = filter_pred_cpu; + else + fn = select_comparison_fn(pred->op, field->size, field->is_signed); if (!fn) { parse_error(ps, FILT_ERR_INVALID_OP, 0); -- cgit v1.2.3