From 9dce58d30d1005e0cbac40789429cd3543d80836 Mon Sep 17 00:00:00 2001 From: Matthew Dempsky Date: Wed, 17 Apr 2019 11:23:53 -0700 Subject: [PATCH] runtime/internal/atomic: remove bad go:noescape annotations on Loadp The //go:noescape directive says that arguments don't leak at all, which is too aggressive of a claim for functions that return pointers derived from their parameters. Remove the directive for now. Long term fix will require a new directive that allows more fine-grained control over escape analysis information supplied for functions implemented in assembly. Also, update the BAD comments in the test cases for Loadp: we really want that *ptr leaks to the result parameter, not that *ptr leaks to the heap. Updates #31525. Change-Id: Ibfa61f2b70daa7ed3223056b57eeee777eef2e31 Reviewed-on: https://go-review.googlesource.com/c/go/+/172578 Run-TryBot: Matthew Dempsky TryBot-Result: Gobot Gobot Reviewed-by: Austin Clements --- src/runtime/internal/atomic/atomic_arm.go | 2 +- src/runtime/internal/atomic/atomic_arm64.go | 2 +- src/runtime/internal/atomic/atomic_mips64x.go | 2 +- src/runtime/internal/atomic/atomic_mipsx.go | 2 +- src/runtime/internal/atomic/atomic_ppc64x.go | 2 +- test/escape_runtime_atomic.go | 4 ++-- test/escape_sync_atomic.go | 4 ++-- 7 files changed, 9 insertions(+), 9 deletions(-) diff --git a/src/runtime/internal/atomic/atomic_arm.go b/src/runtime/internal/atomic/atomic_arm.go index 51b42ba238..abedee0e35 100644 --- a/src/runtime/internal/atomic/atomic_arm.go +++ b/src/runtime/internal/atomic/atomic_arm.go @@ -181,7 +181,7 @@ func armcas(ptr *uint32, old, new uint32) bool //go:noescape func Load(addr *uint32) uint32 -//go:noescape +// NO go:noescape annotation; *addr escapes if result escapes (#31525) func Loadp(addr unsafe.Pointer) unsafe.Pointer //go:noescape diff --git a/src/runtime/internal/atomic/atomic_arm64.go b/src/runtime/internal/atomic/atomic_arm64.go index a2da27e7ed..8e83cc6f53 100644 --- a/src/runtime/internal/atomic/atomic_arm64.go +++ b/src/runtime/internal/atomic/atomic_arm64.go @@ -32,7 +32,7 @@ func Load(ptr *uint32) uint32 //go:noescape func Load64(ptr *uint64) uint64 -//go:noescape +// NO go:noescape annotation; *ptr escapes if result escapes (#31525) func Loadp(ptr unsafe.Pointer) unsafe.Pointer //go:noescape diff --git a/src/runtime/internal/atomic/atomic_mips64x.go b/src/runtime/internal/atomic/atomic_mips64x.go index 98a8fca929..ca2e509266 100644 --- a/src/runtime/internal/atomic/atomic_mips64x.go +++ b/src/runtime/internal/atomic/atomic_mips64x.go @@ -32,7 +32,7 @@ func Load(ptr *uint32) uint32 //go:noescape func Load64(ptr *uint64) uint64 -//go:noescape +// NO go:noescape annotation; *ptr escapes if result escapes (#31525) func Loadp(ptr unsafe.Pointer) unsafe.Pointer //go:noescape diff --git a/src/runtime/internal/atomic/atomic_mipsx.go b/src/runtime/internal/atomic/atomic_mipsx.go index 1cd6d9a9ce..79eb582232 100644 --- a/src/runtime/internal/atomic/atomic_mipsx.go +++ b/src/runtime/internal/atomic/atomic_mipsx.go @@ -116,7 +116,7 @@ func Xchguintptr(ptr *uintptr, new uintptr) uintptr //go:noescape func Load(ptr *uint32) uint32 -//go:noescape +// NO go:noescape annotation; *ptr escapes if result escapes (#31525) func Loadp(ptr unsafe.Pointer) unsafe.Pointer //go:noescape diff --git a/src/runtime/internal/atomic/atomic_ppc64x.go b/src/runtime/internal/atomic/atomic_ppc64x.go index 4f1a95c5bd..0e9a51f6a1 100644 --- a/src/runtime/internal/atomic/atomic_ppc64x.go +++ b/src/runtime/internal/atomic/atomic_ppc64x.go @@ -32,7 +32,7 @@ func Load(ptr *uint32) uint32 //go:noescape func Load64(ptr *uint64) uint64 -//go:noescape +// NO go:noescape annotation; *ptr escapes if result escapes (#31525) func Loadp(ptr unsafe.Pointer) unsafe.Pointer //go:noescape diff --git a/test/escape_runtime_atomic.go b/test/escape_runtime_atomic.go index 6dfd4aa211..efe2013fb9 100644 --- a/test/escape_runtime_atomic.go +++ b/test/escape_runtime_atomic.go @@ -13,8 +13,8 @@ import ( "unsafe" ) -// BAD: should be "leaking param content". -func Loadp(addr unsafe.Pointer) unsafe.Pointer { // ERROR "leaking param: addr" +// BAD: should always be "leaking param: addr to result ~r1 level=1$". +func Loadp(addr unsafe.Pointer) unsafe.Pointer { // ERROR "leaking param: addr( to result ~r1 level=1)?$" return atomic.Loadp(addr) } diff --git a/test/escape_sync_atomic.go b/test/escape_sync_atomic.go index 8da71a0ccf..e509b37511 100644 --- a/test/escape_sync_atomic.go +++ b/test/escape_sync_atomic.go @@ -13,8 +13,8 @@ import ( "unsafe" ) -// BAD: should be "leaking param content". -func LoadPointer(addr *unsafe.Pointer) unsafe.Pointer { // ERROR "leaking param: addr" +// BAD: should be "leaking param: addr to result ~r1 level=1$". +func LoadPointer(addr *unsafe.Pointer) unsafe.Pointer { // ERROR "leaking param: addr$" return atomic.LoadPointer(addr) }