Sorry, just realized I sent the patch that was against perf_fuzzer and not against the trinity tree. Here's an updated patch.
This patch adds a create_mostly_valid_global_event case to the perf_event_open() code. Without this patch it is extremely unlikely that a global (not per-process) event would be randomly created. Most users will not notice a change, as you can only create global events as root or else if /proc/sys/kernel/perf_event_paranoid is set to < 1 (the default is 1). With this change some of the more obscure event types such as uncore, northbridge, and RAPL power events are occasionally properly created. Signed-off-by: Vince Weaver <[email protected]> diff --git a/syscalls/perf_event_open.c b/syscalls/perf_event_open.c index c4ccafd..7c20350 100644 --- a/syscalls/perf_event_open.c +++ b/syscalls/perf_event_open.c @@ -1089,6 +1089,36 @@ static void create_mostly_valid_sampling_event(struct perf_event_attr *attr, } + +/* Creates a global event: one that is not per-process, but system-wide */ +/* To be valid must be created with pid=-1 and cpu being a valid CPU. */ +/* Also usually only root can create these unless */ +/* /proc/sys/kernel/perf_event_paranoid is less than 1. */ +/* Most custom PMU types (uncore/northbridge/RAPL) are covered here. */ + +static void create_mostly_valid_global_event(struct perf_event_attr *attr, + int group_leader) +{ + + attr->type = random_event_type(); + attr->size = random_attr_size(); + attr->config = random_event_config(&attr->type, + &attr->config1, + &attr->config2); + + attr->read_format = random_read_format(); + + /* Bitfield parameters, mostly boolean */ + attr->disabled = rand_bool(); + attr->inherit = rand_bool(); + if (group_leader) { + attr->pinned = rand_bool(); + } + + /* Not setting most other paramaters */ + /* As they tend to be not valid in a global event */ +} + /* Creates a completely random event, unlikely to be valid */ static void create_random_event(struct perf_event_attr *attr) { @@ -1244,7 +1274,7 @@ void sanitise_perf_event_open(int childno) shm->syscall[childno].a2 = pid; /* set up attr structure */ - switch (rand() % 3) { + switch (rand() % 4) { case 0: create_mostly_valid_counting_event(attr,group_leader); break; @@ -1252,6 +1282,9 @@ void sanitise_perf_event_open(int childno) create_mostly_valid_sampling_event(attr,group_leader); break; case 2: + create_mostly_valid_global_event(attr,group_leader); + break; + case 3: create_random_event(attr); break; default: -- To unsubscribe from this list: send the line "unsubscribe trinity" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
