From eb63ef9d6676dc0edb112cd297820306a327017a Mon Sep 17 00:00:00 2001 From: Ian Lance Taylor Date: Fri, 22 Aug 2025 13:47:42 -0700 Subject: runtime: panic if cleanup function closes over cleanup pointer MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This would catch problems like https://go.dev/cl/696295. Benchmark effect with this CL plus CL 697535: goos: linux goarch: amd64 pkg: runtime cpu: 12th Gen Intel(R) Core(TM) i7-1260P │ /tmp/foo.1 │ /tmp/foo.2 │ │ sec/op │ sec/op vs base │ AddCleanupAndStop-16 81.93n ± 1% 82.87n ± 1% +1.14% (p=0.041 n=10) For #75066 Change-Id: Ia41d0d6b88baebf6055cb7e5d42bc8210b31630f Reviewed-on: https://go-review.googlesource.com/c/go/+/714000 Reviewed-by: Michael Pratt Reviewed-by: Michael Knyszek Auto-Submit: Ian Lance Taylor LUCI-TryBot-Result: Go LUCI --- src/runtime/testdata/testprog/checkfinalizers.go | 27 ++++++++++++++++++++++-- 1 file changed, 25 insertions(+), 2 deletions(-) (limited to 'src/runtime/testdata') diff --git a/src/runtime/testdata/testprog/checkfinalizers.go b/src/runtime/testdata/testprog/checkfinalizers.go index ea352a4e3e..9f082a25ff 100644 --- a/src/runtime/testdata/testprog/checkfinalizers.go +++ b/src/runtime/testdata/testprog/checkfinalizers.go @@ -28,17 +28,40 @@ func DetectFinalizerAndCleanupLeaks() { // Leak a cleanup. cLeak := new(T) + + // Use an extra closure to avoid the simple + // checking done by AddCleanup. + var closeOverCLeak func(int) + closeOverCLeak = func(x int) { + // Use recursion to avoid inlining. + if x <= 0 { + **cLeak = x + } else { + closeOverCLeak(x - 1) + } + } + runtime.AddCleanup(cLeak, func(x int) { - **cLeak = x + closeOverCLeak(x) }, int(0)) // Have a regular cleanup to make sure it doesn't trip the detector. cNoLeak := new(T) runtime.AddCleanup(cNoLeak, func(_ int) {}, int(0)) + // Like closeOverCLeak. + var closeOverCNoLeak func(int) + closeOverCNoLeak = func(x int) { + if x <= 0 { + **cNoLeak = x + } else { + closeOverCNoLeak(x - 1) + } + } + // Add a cleanup that only temporarily leaks cNoLeak. runtime.AddCleanup(cNoLeak, func(x int) { - **cNoLeak = x + closeOverCNoLeak(x) }, int(0)).Stop() if !asan.Enabled && !race.Enabled { -- cgit v1.3