runtime: set vdsoSP to caller's SP consistently

m.vdsoSP should be set to the SP of the caller of nanotime1,
instead of the SP of nanotime1 itself, which matches m.vdsoPC.
Otherwise the unmatched vdsoPC and vdsoSP would make the stack
trace look like recursive.

We already do it correctly on AMD64, 386, and RISCV64. This CL
fixes the rest.

Fixes #47324.

Change-Id: I98b6fcfbe9fc6bdd28b8fe2a1299b7c505371dd4
Reviewed-on: https://go-review.googlesource.com/c/go/+/337590
Trust: Cherry Mui <cherryyz@google.com>
Trust: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/src/runtime/pprof/pprof_test.go b/src/runtime/pprof/pprof_test.go
index e0d32a0f54..5b9ad50746 100644
--- a/src/runtime/pprof/pprof_test.go
+++ b/src/runtime/pprof/pprof_test.go
@@ -1544,3 +1544,33 @@ func TestTryAdd(t *testing.T) {
 		})
 	}
 }
+
+func TestTimeVDSO(t *testing.T) {
+	// Test that time functions have the right stack trace. In particular,
+	// it shouldn't be recursive.
+
+	p := testCPUProfile(t, stackContains, []string{"time.now"}, avoidFunctions(), func(dur time.Duration) {
+		t0 := time.Now()
+		for {
+			t := time.Now()
+			if t.Sub(t0) >= dur {
+				return
+			}
+		}
+	})
+
+	// Check for recursive time.now sample.
+	for _, sample := range p.Sample {
+		var seenNow bool
+		for _, loc := range sample.Location {
+			for _, line := range loc.Line {
+				if line.Function.Name == "time.now" {
+					if seenNow {
+						t.Fatalf("unexpected recursive time.now")
+					}
+					seenNow = true
+				}
+			}
+		}
+	}
+}