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 <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>
diff --git a/src/runtime/internal/atomic/atomic_arm.go b/src/runtime/internal/atomic/atomic_arm.go
index 51b42ba..abedee0 100644
--- a/src/runtime/internal/atomic/atomic_arm.go
+++ b/src/runtime/internal/atomic/atomic_arm.go
@@ -181,7 +181,7 @@
//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 a2da27e..8e83cc6 100644
--- a/src/runtime/internal/atomic/atomic_arm64.go
+++ b/src/runtime/internal/atomic/atomic_arm64.go
@@ -32,7 +32,7 @@
//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 98a8fca..ca2e509 100644
--- a/src/runtime/internal/atomic/atomic_mips64x.go
+++ b/src/runtime/internal/atomic/atomic_mips64x.go
@@ -32,7 +32,7 @@
//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 1cd6d9a..79eb582 100644
--- a/src/runtime/internal/atomic/atomic_mipsx.go
+++ b/src/runtime/internal/atomic/atomic_mipsx.go
@@ -116,7 +116,7 @@
//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 4f1a95c..0e9a51f 100644
--- a/src/runtime/internal/atomic/atomic_ppc64x.go
+++ b/src/runtime/internal/atomic/atomic_ppc64x.go
@@ -32,7 +32,7 @@
//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 6dfd4aa..efe2013 100644
--- a/test/escape_runtime_atomic.go
+++ b/test/escape_runtime_atomic.go
@@ -13,8 +13,8 @@
"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 8da71a0..e509b37 100644
--- a/test/escape_sync_atomic.go
+++ b/test/escape_sync_atomic.go
@@ -13,8 +13,8 @@
"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)
}
