runtime/pprof: check Getrusage return value in addMaxRSS

Depending on the implementation of the getrusage syscall/function, the
value of rusage.Maxrss may be undefined in case of an error. Thus, only
report MaxRSS in case of no error.

Change-Id: I7572ccc53c49eb460e53bded3eb41736eed8d2ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/424815
Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
Reviewed-by: Joedian Reid <joedian@golang.org>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

diff --git a/src/runtime/pprof/pprof_rusage.go b/src/runtime/pprof/pprof_rusage.go
index 984a32e79d4561eb91e1d343eaa8c14d1fcfb195..a3ca4c8d5dd7ebbf0546a2a0e6b8cdb6b7007825 100644 (file)
--- a/src/runtime/pprof/pprof_rusage.go
+++ b/src/runtime/pprof/pprof_rusage.go
@@ -28,6 +28,8 @@ func addMaxRSS(w io.Writer) {
        }
 
        var rusage syscall.Rusage
-       syscall.Getrusage(syscall.RUSAGE_SELF, &rusage)
-       fmt.Fprintf(w, "# MaxRSS = %d\n", uintptr(rusage.Maxrss)*rssToBytes)
+       err := syscall.Getrusage(syscall.RUSAGE_SELF, &rusage)
+       if err == nil {
+               fmt.Fprintf(w, "# MaxRSS = %d\n", uintptr(rusage.Maxrss)*rssToBytes)
+       }
 }