From 2d4c1ff73992fa817213c7866be8030d9c78b5ba Mon Sep 17 00:00:00 2001 From: Austin Clements Date: Fri, 13 Jul 2018 17:29:39 -0400 Subject: [PATCH] runtime: don't create heap hints outside TSAN's supported heap TSAN for Go only supports heap address in the range [0x00c000000000, 0x00e000000000). However, we currently create heap hints of the form 0xXXc000000000 for XX between 0x00 and 0x7f. Even for XX=0x01, this hint is outside TSAN's supported heap address range. Fix this by creating a slightly different set of hints in race mode, all of which fall inside TSAN's heap address range. This should fix TestArenaCollision flakes. That test forces the runtime to use later heap hints. Currently, this always results in TSAN "failed to allocate" failures on Windows (which happens to have a slightly more constrained TSAN layout than non-Windows). Most of the time we don't notice these failures, but sometimes it crashes TSAN, leading to a test failure. Fixes #25698. Change-Id: I8926cd61f0ee5ee00efa77b283f7b809c555be46 Reviewed-on: https://go-review.googlesource.com/123780 Run-TryBot: Austin Clements TryBot-Result: Gobot Gobot Reviewed-by: Rick Hudson --- src/runtime/malloc.go | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/src/runtime/malloc.go b/src/runtime/malloc.go index e75edf05fd..07e0a67240 100644 --- a/src/runtime/malloc.go +++ b/src/runtime/malloc.go @@ -427,6 +427,14 @@ func mallocinit() { p = uintptr(i)<<40 | uintptrMask&(0x0013<<28) case GOARCH == "arm64": p = uintptr(i)<<40 | uintptrMask&(0x0040<<32) + case raceenabled: + // The TSAN runtime requires the heap + // to be in the range [0x00c000000000, + // 0x00e000000000). + p = uintptr(i)<<32 | uintptrMask&(0x00c0<<32) + if p >= uintptrMask&0x00e000000000 { + continue + } default: p = uintptr(i)<<40 | uintptrMask&(0x00c0<<32) } -- 2.50.0