Merge pull request iovisor#1765 from palmtenor/extraflag

Add extra_flag option to bpf_attach_perf_event_raw
drcwr · May 17, 2018 · b8fccc5 · b8fccc5
2 parents 683c19a + bf2513d
commit b8fccc5
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Showing 4 changed files with 10 additions and 7 deletions.
diff --git a/src/cc/api/BPF.cc b/src/cc/api/BPF.cc
@@ -324,7 +324,8 @@ StatusTuple BPF::attach_perf_event(uint32_t ev_type, uint32_t ev_config,
 
 StatusTuple BPF::attach_perf_event_raw(void* perf_event_attr,
  const std::string& probe_func, pid_t pid,
- int cpu, int group_fd) {
+ int cpu, int group_fd,
+ unsigned long extra_flags) {
  auto attr = static_cast<struct perf_event_attr*>(perf_event_attr);
  auto ev_pair = std::make_pair(attr->type, attr->config);
  if (perf_events_.find(ev_pair) != perf_events_.end())
@@ -342,7 +343,8 @@ StatusTuple BPF::attach_perf_event_raw(void* perf_event_attr,
  auto fds = new std::vector<std::pair<int, int>>();
  fds->reserve(cpus.size());
  for (int i : cpus) {
- int fd = bpf_attach_perf_event_raw(probe_fd, attr, pid, i, group_fd);
+ int fd = bpf_attach_perf_event_raw(probe_fd, attr, pid, i, group_fd,
+ extra_flags);
  if (fd < 0) {
  for (const auto& it : *fds)
  close(it.second);

diff --git a/src/cc/api/BPF.h b/src/cc/api/BPF.h
@@ -88,7 +88,8 @@ class BPF {
  StatusTuple attach_perf_event_raw(void* perf_event_attr,
  const std::string& probe_func,
  pid_t pid = -1, int cpu = -1,
- int group_fd = -1);
+ int group_fd = -1,
+ unsigned long extra_flags = 0);
  StatusTuple detach_perf_event(uint32_t ev_type, uint32_t ev_config);
  StatusTuple detach_perf_event_raw(void* perf_event_attr);
  std::string get_syscall_fnname(const std::string& name);

diff --git a/src/cc/libbpf.c b/src/cc/libbpf.c
@@ -1305,9 +1305,9 @@ int bpf_attach_xdp(const char *dev_name, int progfd, uint32_t flags) {
 }
 
 int bpf_attach_perf_event_raw(int progfd, void *perf_event_attr, pid_t pid,
- int cpu, int group_fd) {
+ int cpu, int group_fd, unsigned long extra_flags) {
  int fd = syscall(__NR_perf_event_open, perf_event_attr, pid, cpu, group_fd,
- PERF_FLAG_FD_CLOEXEC);
+ PERF_FLAG_FD_CLOEXEC | extra_flags);
  if (fd < 0) {
  perror("perf_event_open failed");
  return -1;
@@ -1351,7 +1351,7 @@ int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config,
  attr.sample_period = sample_period;
  }
 
- return bpf_attach_perf_event_raw(progfd, &attr, pid, cpu, group_fd);
+ return bpf_attach_perf_event_raw(progfd, &attr, pid, cpu, group_fd, 0);
 }
 
 int bpf_close_perf_event_fd(int fd) {

diff --git a/src/cc/libbpf.h b/src/cc/libbpf.h
@@ -93,7 +93,7 @@ int bpf_attach_xdp(const char *dev_name, int progfd, uint32_t flags);
 // attach a prog expressed by progfd to run on a specific perf event. The perf
 // event will be created using the perf_event_attr pointer provided.
 int bpf_attach_perf_event_raw(int progfd, void *perf_event_attr, pid_t pid,
- int cpu, int group_fd);
+ int cpu, int group_fd, unsigned long extra_flags);
 // attach a prog expressed by progfd to run on a specific perf event, with
 // certain sample period or sample frequency
 int bpf_attach_perf_event(int progfd, uint32_t ev_type, uint32_t ev_config,