Merge tag 'perf-tools-for-v5.14-2021-07-10' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux

Pull more perf tool updates from Arnaldo Carvalho de Melo:
 "New features:

   - Enable use of BPF counters with 'perf stat --for-each-cgroup',
     using per-CPU 'cgroup-switch' events with an attached BPF program
     that does aggregation per-cgroup in the kernel instead of using
     per-cgroup perf events.

   - Add Topdown metrics L2 events as default events in 'perf stat' for
     systems having those events.

  Hardware tracing:

   - Add a config for max loops without consuming a packet in the Intel
     PT packet decoder, set via 'perf config intel-pt.max-loops=N'

  Hardware enablement:

   - Disable misleading NMI watchdog message in 'perf stat' on hybrid
     systems such as Intel Alder Lake.

   - Add a dummy event on hybrid systems to collect metadata records.

   - Add 24x7 nest metric events for the Power10 platform.

  Fixes:

   - Fix event parsing for PMUs starting with the same prefix.

   - Fix the 'perf trace' 'trace' alias installation dir.

   - Fix buffer size to report iregs in perf script python scripts,
     supporting the extended registers in PowerPC.

   - Fix overflow in elf_sec__is_text().

   - Fix 's' on source line when disasm is empty in the annotation TUI,
     accessible via 'perf annotate', 'perf report' and 'perf top'.

   - Plug leaks in scandir() returned dirent entries in 'perf test' when
     sorting the shell tests.

   - Fix --task and --stat with pipe input in 'perf report'.

   - Fix 'perf probe' use of debuginfo files by build id.

   - If a DSO has both dynsym and symtab ELF sections, read from both
     when loading the symbol table, fixing a problem processing Fedora
     32 glibc DSOs.

  Libraries:

   - Add grouping of events to libperf, from code in tools/perf,
     allowing libperf users to use that mode.

  Misc:

   - Filter plt stubs from the 'perf probe --functions' output.

   - Update UAPI header copies for asound, DRM, mman-common.h and the
     ones affected by the quotactl_fd syscall"

* tag 'perf-tools-for-v5.14-2021-07-10' of git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux: (29 commits)
  perf test: Add free() calls for scandir() returned dirent entries
  libperf: Add tests for perf_evlist__set_leader()
  libperf: Remove BUG_ON() from library code in get_group_fd()
  libperf: Add group support to perf_evsel__open()
  perf tools: Fix pattern matching for same substring in different PMU type
  perf record: Add a dummy event on hybrid systems to collect metadata records
  perf stat: Add Topdown metrics L2 events as default events
  libperf: Adopt evlist__set_leader() from tools/perf as perf_evlist__set_leader()
  libperf: Move 'nr_groups' from tools/perf to evlist::nr_groups
  libperf: Move 'leader' from tools/perf to perf_evsel::leader
  libperf: Move 'idx' from tools/perf to perf_evsel::idx
  libperf: Change tests to single static and shared binaries
  perf intel-pt: Add a config for max loops without consuming a packet
  perf stat: Disable the NMI watchdog message on hybrid
  perf vendor events power10: Adds 24x7 nest metric events for power10 platform
  perf script python: Fix buffer size to report iregs in perf script
  perf trace: Fix the perf trace link location
  perf top: Fix overflow in elf_sec__is_text()
  perf annotate: Fix 's' on source line when disasm is empty
  perf probe: Do not show @plt function by default
  ...

1 files changed, 38 insertions, 4 deletions

diff --git a/tools/lib/perf/evsel.c b/tools/lib/perf/evsel.c
index bd8c2f19ef74..d8886720e83d 100644
--- a/tools/lib/perf/evsel.c
+++ b/tools/lib/perf/evsel.c
@@ -17,11 +17,15 @@
 #include <linux/string.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>
+#include <asm/bug.h>
 
-void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr)
+void perf_evsel__init(struct perf_evsel *evsel, struct perf_event_attr *attr,
+		      int idx)
 {
 	INIT_LIST_HEAD(&evsel->node);
 	evsel->attr = *attr;
+	evsel->idx  = idx;
+	evsel->leader = evsel;
 }
 
 struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr)
@@ -29,7 +33,7 @@ struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr)
 	struct perf_evsel *evsel = zalloc(sizeof(*evsel));
 
 	if (evsel != NULL)
-		perf_evsel__init(evsel, attr);
+		perf_evsel__init(evsel, attr, 0);
 
 	return evsel;
 }
@@ -73,6 +77,32 @@ sys_perf_event_open(struct perf_event_attr *attr,
 	return syscall(__NR_perf_event_open, attr, pid, cpu, group_fd, flags);
 }
 
+static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread, int *group_fd)
+{
+	struct perf_evsel *leader = evsel->leader;
+	int fd;
+
+	if (evsel == leader) {
+		*group_fd = -1;
+		return 0;
+	}
+
+	/*
+	 * Leader must be already processed/open,
+	 * if not it's a bug.
+	 */
+	if (!leader->fd)
+		return -ENOTCONN;
+
+	fd = FD(leader, cpu, thread);
+	if (fd == -1)
+		return -EBADF;
+
+	*group_fd = fd;
+
+	return 0;
+}
+
 int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
 		     struct perf_thread_map *threads)
 {
@@ -108,11 +138,15 @@ int perf_evsel__open(struct perf_evsel *evsel, struct perf_cpu_map *cpus,
 
 	for (cpu = 0; cpu < cpus->nr; cpu++) {
 		for (thread = 0; thread < threads->nr; thread++) {
-			int fd;
+			int fd, group_fd;
+
+			err = get_group_fd(evsel, cpu, thread, &group_fd);
+			if (err < 0)
+				return err;
 
 			fd = sys_perf_event_open(&evsel->attr,
 						 threads->map[thread].pid,
-						 cpus->map[cpu], -1, 0);
+						 cpus->map[cpu], group_fd, 0);
 
 			if (fd < 0)
 				return -errno;