runtime: add msan support on freebsd/amd64

Adjust build constraints and change the runtime to call the C mmap function when using cgo. R=go1.20 For #53298 Change-Id: If9c3306dc16a8645d1bb9be0343e0472d6c4783f Reviewed-on: https://go-review.googlesource.com/c/go/+/411274 Reviewed-by: Bryan Mills <[email protected]> Reviewed-by: Ian Lance Taylor <[email protected]> Reviewed-by: Michael Pratt <[email protected]>
cloudflare · Oct 14, 2022 · 5fde02e · 5fde02e
1 parent 76e4833
commit 5fde02e
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Showing 6 changed files with 38 additions and 7 deletions.
diff --git a/src/runtime/cgo/gcc_mmap.c b/src/runtime/cgo/gcc_mmap.c
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,amd64 linux,arm64 linux,ppc64le
+// +build linux,amd64 linux,arm64 linux,ppc64le freebsd,amd64
 
 #include <errno.h>
 #include <stdint.h>

diff --git a/src/runtime/cgo/mmap.go b/src/runtime/cgo/mmap.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build (linux && amd64) || (linux && arm64)
+//go:build (linux && amd64) || (linux && arm64) || (freebsd && amd64)
 
 package cgo
 

diff --git a/src/runtime/cgo_mmap.go b/src/runtime/cgo_mmap.go
@@ -4,7 +4,7 @@
 
 // Support for memory sanitizer. See runtime/cgo/mmap.go.
 
-//go:build (linux && amd64) || (linux && arm64)
+//go:build (linux && amd64) || (linux && arm64) || (freebsd && amd64)
 
 package runtime
 

diff --git a/src/runtime/mmap.go b/src/runtime/mmap.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build !aix && !darwin && !js && (!linux || !amd64) && (!linux || !arm64) && !openbsd && !plan9 && !solaris && !windows
+//go:build !aix && !darwin && !js && (!linux || !amd64) && (!linux || !arm64) && (!freebsd || !amd64) && !openbsd && !plan9 && !solaris && !windows
 
 package runtime
 

diff --git a/src/runtime/msan/msan.go b/src/runtime/msan/msan.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build msan && linux && (amd64 || arm64)
+//go:build msan && ((linux && (amd64 || arm64)) || (freebsd && amd64))
 
 package msan
 

diff --git a/src/runtime/sys_freebsd_amd64.s b/src/runtime/sys_freebsd_amd64.s
@@ -385,7 +385,7 @@ sigtrampnog:
  MOVQ _cgo_callers(SB), AX
  JMP AX
 
-TEXT runtime·mmap(SB),NOSPLIT,$0
+TEXT runtime·sysMmap(SB),NOSPLIT,$0
  MOVQ addr+0(FP), DI // arg 1 addr
  MOVQ n+8(FP), SI // arg 2 len
  MOVL prot+16(FP), DX // arg 3 prot
@@ -403,7 +403,25 @@ ok:
  MOVQ $0, err+40(FP)
  RET
 
-TEXT runtime·munmap(SB),NOSPLIT,$0
+// Call the function stored in _cgo_mmap using the GCC calling convention.
+// This must be called on the system stack.
+TEXT runtime·callCgoMmap(SB),NOSPLIT,$16
+ MOVQ addr+0(FP), DI
+ MOVQ n+8(FP), SI
+ MOVL prot+16(FP), DX
+ MOVL flags+20(FP), CX
+ MOVL fd+24(FP), R8
+ MOVL off+28(FP), R9
+ MOVQ _cgo_mmap(SB), AX
+ MOVQ SP, BX
+ ANDQ $~15, SP // alignment as per amd64 psABI
+ MOVQ BX, 0(SP)
+ CALL AX
+ MOVQ 0(SP), SP
+ MOVQ AX, ret+32(FP)
+ RET
+
+TEXT runtime·sysMunmap(SB),NOSPLIT,$0
  MOVQ addr+0(FP), DI // arg 1 addr
  MOVQ n+8(FP), SI // arg 2 len
  MOVL $SYS_munmap, AX
@@ -412,6 +430,19 @@ TEXT runtime·munmap(SB),NOSPLIT,$0
  MOVL $0xf1, 0xf1 // crash
  RET
 
+// Call the function stored in _cgo_munmap using the GCC calling convention.
+// This must be called on the system stack.
+TEXT runtime·callCgoMunmap(SB),NOSPLIT,$16-16
+ MOVQ addr+0(FP), DI
+ MOVQ n+8(FP), SI
+ MOVQ _cgo_munmap(SB), AX
+ MOVQ SP, BX
+ ANDQ $~15, SP // alignment as per amd64 psABI
+ MOVQ BX, 0(SP)
+ CALL AX
+ MOVQ 0(SP), SP
+ RET
+
 TEXT runtime·madvise(SB),NOSPLIT,$0
  MOVQ addr+0(FP), DI
  MOVQ n+8(FP), SI