From c684dfcb8a8fe38a8414bfd07b94e9995e5cd308 Mon Sep 17 00:00:00 2001 From: Michael Anthony Knyszek Date: Thu, 22 May 2025 00:29:14 +0000 Subject: [PATCH] runtime: don't spin looking for a tiny alloc address with asan or race CL 674655 modified the checkfinalizers test to spin looking for an appropriate address to trip the detector, but this doesn't work with ASAN or in race mode, which both disable the tiny allocator. Fixes #73834. Change-Id: I27416da1f29cd953271698551e9ce9724484c683 Reviewed-on: https://go-review.googlesource.com/c/go/+/675395 LUCI-TryBot-Result: Go LUCI Reviewed-by: Michael Pratt --- .../testdata/testprog/checkfinalizers.go | 31 ++++++++++++------- 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/src/runtime/testdata/testprog/checkfinalizers.go b/src/runtime/testdata/testprog/checkfinalizers.go index a2fe104462..ea352a4e3e 100644 --- a/src/runtime/testdata/testprog/checkfinalizers.go +++ b/src/runtime/testdata/testprog/checkfinalizers.go @@ -5,6 +5,8 @@ package main import ( + "internal/asan" + "internal/race" "runtime" "runtime/debug" "unsafe" @@ -39,20 +41,25 @@ func DetectFinalizerAndCleanupLeaks() { **cNoLeak = x }, int(0)).Stop() - // Ensure we create an allocation into a tiny block that shares space among several values. - var ctLeak *tiny - for { - tinySink = ctLeak - ctLeak = new(tiny) - *ctLeak = tiny(55) - // Make sure the address is an odd value. This is sufficient to - // be certain that we're sharing a block with another value and - // trip the detector. - if uintptr(unsafe.Pointer(ctLeak))%2 != 0 { - break + if !asan.Enabled && !race.Enabled { + // Ensure we create an allocation into a tiny block that shares space among several values. + // + // Don't do this with ASAN and in race mode, where the tiny allocator is disabled. + // We might just loop forever here in that case. + var ctLeak *tiny + for { + tinySink = ctLeak + ctLeak = new(tiny) + *ctLeak = tiny(55) + // Make sure the address is an odd value. This is sufficient to + // be certain that we're sharing a block with another value and + // trip the detector. + if uintptr(unsafe.Pointer(ctLeak))%2 != 0 { + break + } } + runtime.AddCleanup(ctLeak, func(_ struct{}) {}, struct{}{}) } - runtime.AddCleanup(ctLeak, func(_ struct{}) {}, struct{}{}) // Leak a finalizer. fLeak := new(T) -- 2.50.0