perf lock contention: Track and show siglock with address

Likewise, we can display siglock by following the pointer like
current->sighand->siglock.

  $ sudo ./perf lock con -abl -- sleep 1
   contended   total wait     max wait     avg wait            address   symbol

          16      2.18 ms    305.35 us    136.34 us   ffffffff92e06080   tasklist_lock
          28    521.78 us     31.16 us     18.63 us   ffff8cc703783ec4
           7    119.03 us     23.55 us     17.00 us   ffff8ccb92479440
          15     88.29 us     10.06 us      5.89 us   ffff8cd560b5f380   siglock
           7     37.67 us      9.16 us      5.38 us   ffff8d053daf0c80
           5      8.81 us      4.92 us      1.76 us   ffff8d053d6b0c80
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Cc: Boqun Feng <boqun.feng@gmail.com>
Cc: Hao Luo <haoluo@google.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Song Liu <song@kernel.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: bpf@vger.kernel.org
Link: https://lore.kernel.org/r/20230313204825.2665483-2-namhyung@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/builtin-lock.c

@@ -1662,8 +1662,7 @@ static void print_contention_result(struct lock_contention *con)
 				pid, pid == -1 ? "Unknown" : thread__comm_str(t));
 			break;
 		case LOCK_AGGR_ADDR:
-			pr_info("  %016llx   %s\n", (unsigned long long)st->addr,
-				(st->flags & LCD_F_MMAP_LOCK) ? "mmap_lock" : st->name);
+			pr_info("  %016llx   %s\n", (unsigned long long)st->addr, st->name);
 			break;
 		default:
 			break;

tools/perf/util/bpf_lock_contention.c

@@ -169,7 +169,7 @@ int lock_contention_stop(void)
 
 static const char *lock_contention_get_name(struct lock_contention *con,
 					    struct contention_key *key,
-					    u64 *stack_trace)
+					    u64 *stack_trace, u32 flags)
 {
 	int idx = 0;
 	u64 addr;
@@ -198,6 +198,10 @@ static const char *lock_contention_get_name(struct lock_contention *con,
 	}
 
 	if (con->aggr_mode == LOCK_AGGR_ADDR) {
+		if (flags & LCD_F_MMAP_LOCK)
+			return "mmap_lock";
+		if (flags & LCD_F_SIGHAND_LOCK)
+			return "siglock";
 		sym = machine__find_kernel_symbol(machine, key->lock_addr, &kmap);
 		if (sym)
 			name = sym->name;
@@ -301,7 +305,7 @@ int lock_contention_read(struct lock_contention *con)
 			goto next;
 		}
 
-		name = lock_contention_get_name(con, &key, stack_trace);
+		name = lock_contention_get_name(con, &key, stack_trace, data.flags);
 		st = lock_stat_findnew(ls_key, name, data.flags);
 		if (st == NULL)
 			break;

tools/perf/util/bpf_skel/lock_contention.bpf.c

@@ -242,6 +242,11 @@ static inline __u32 check_lock_type(__u64 lock, __u32 flags)
 				return LCD_F_MMAP_LOCK;
 		}
 		break;
+	case LCB_F_SPIN:  /* spinlock */
+		curr = bpf_get_current_task_btf();
+		if (&curr->sighand->siglock == (void *)lock)
+			return LCD_F_SIGHAND_LOCK;
+		break;
 	default:
 		break;
 	}

tools/perf/util/bpf_skel/lock_data.h

@@ -19,7 +19,8 @@ struct contention_task_data {
  * Upper bits of the flags in the contention_data are used to identify
  * some well-known locks which do not have symbols (non-global locks).
  */
-#define LCD_F_MMAP_LOCK  (1U << 31)
+#define LCD_F_MMAP_LOCK		(1U << 31)
+#define LCD_F_SIGHAND_LOCK	(1U << 30)
 
 struct contention_data {
 	u64 total_time;