runtime: fix errno sign for some mmap and mincore cases

The caller of mmap expects it to return a positive errno value, but the
linux-arm64 and nacl-386 system calls returned a negative errno value.
Correct them to negate the errno value.

The caller of mincore expects it to return a negative errno value (yes,
this is inconsistent), but the linux-mips64x and linux-ppc64x system
call returned a positive errno value.  Correct them to negate the errno
value.

Add a test that mmap returns errno with the correct sign.  Brad added a
test for mincore's errno value in https://golang.org/cl/19457.

Fixes #14297.

Change-Id: I2b93f32e679bd1eae1c9aef9ae7bcf0ba39521b5
Reviewed-on: https://go-review.googlesource.com/19455
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Reviewed-by: Minux Ma <minux@golang.org>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>

diff --git a/src/runtime/export_linux_test.go b/src/runtime/export_linux_test.go
index c8b97466764597482126f6c3723321393dc43dcf..61d6ae4bf2f0d64c083351693a67a57724335158 100644 (file)
--- a/src/runtime/export_linux_test.go
+++ b/src/runtime/export_linux_test.go
@@ -7,3 +7,4 @@
 package runtime
 
 var NewOSProc0 = newosproc0
+var Mincore = mincore

diff --git a/src/runtime/export_mmap_test.go b/src/runtime/export_mmap_test.go
new file mode 100644 (file)
index 0000000..11ea076
--- /dev/null
+++ b/src/runtime/export_mmap_test.go
@@ -0,0 +1,15 @@
+// Copyright 2016 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+
+// Export guts for testing.
+
+package runtime
+
+var Mmap = mmap
+
+const ENOMEM = _ENOMEM
+const MAP_ANON = _MAP_ANON
+const MAP_PRIVATE = _MAP_PRIVATE

diff --git a/src/runtime/export_test.go b/src/runtime/export_test.go
index b09022b53cc01f1536c46c27a11396048db699be..5400c1d14eaae2d0fe30396357a616aa36572bff 100644 (file)
--- a/src/runtime/export_test.go
+++ b/src/runtime/export_test.go
@@ -28,8 +28,6 @@ var Exitsyscall = exitsyscall
 var LockedOSThread = lockedOSThread
 var Xadduintptr = atomic.Xadduintptr
 
-var Mincore = mincore
-
 var FuncPC = funcPC
 
 var Fastlog2 = fastlog2

diff --git a/src/runtime/mem_bsd.go b/src/runtime/mem_bsd.go
index 1e388ec7281646e8f63141d3132bd2390554aa23..c3fe6106d7dcf66816eec9dfa48e10526dd56d12 100644 (file)
--- a/src/runtime/mem_bsd.go
+++ b/src/runtime/mem_bsd.go
@@ -59,9 +59,9 @@ func sysReserve(v unsafe.Pointer, n uintptr, reserved *bool) unsafe.Pointer {
        return p
 }
 
-func sysMap(v unsafe.Pointer, n uintptr, reserved bool, sysStat *uint64) {
-       const _ENOMEM = 12
+const _ENOMEM = 12
 
+func sysMap(v unsafe.Pointer, n uintptr, reserved bool, sysStat *uint64) {
        mSysStatInc(sysStat, n)
 
        // On 64-bit, we don't actually have v reserved, so tread carefully.

diff --git a/src/runtime/os2_nacl.go b/src/runtime/os2_nacl.go
index 0c91e0f7372dba8444fd6fdb0b3fba26718fb48c..d8c88db0adf7258ce3d835d2486d89552d93ce97 100644 (file)
--- a/src/runtime/os2_nacl.go
+++ b/src/runtime/os2_nacl.go
@@ -10,18 +10,19 @@ const (
 
        // native_client/src/trusted/service_runtime/include/sys/errno.h
        // The errors are mainly copied from Linux.
-       _EPERM           = 1        /* Operation not permitted */
-       _ENOENT          = 2        /* No such file or directory */
-       _ESRCH           = 3        /* No such process */
-       _EINTR           = 4        /* Interrupted system call */
-       _EIO             = 5        /* I/O error */
-       _ENXIO           = 6        /* No such device or address */
-       _E2BIG           = 7        /* Argument list too long */
-       _ENOEXEC         = 8        /* Exec format error */
-       _EBADF           = 9        /* Bad file number */
-       _ECHILD          = 10       /* No child processes */
-       _EAGAIN          = 11       /* Try again */
-       _ENOMEM          = 12       /* Out of memory */
+       _EPERM   = 1  /* Operation not permitted */
+       _ENOENT  = 2  /* No such file or directory */
+       _ESRCH   = 3  /* No such process */
+       _EINTR   = 4  /* Interrupted system call */
+       _EIO     = 5  /* I/O error */
+       _ENXIO   = 6  /* No such device or address */
+       _E2BIG   = 7  /* Argument list too long */
+       _ENOEXEC = 8  /* Exec format error */
+       _EBADF   = 9  /* Bad file number */
+       _ECHILD  = 10 /* No child processes */
+       _EAGAIN  = 11 /* Try again */
+       // _ENOMEM is defined in mem_bsd.go for nacl.
+       // _ENOMEM          = 12       /* Out of memory */
        _EACCES          = 13       /* Permission denied */
        _EFAULT          = 14       /* Bad address */
        _EBUSY           = 16       /* Device or resource busy */

diff --git a/src/runtime/runtime_mmap_test.go b/src/runtime/runtime_mmap_test.go
new file mode 100644 (file)
index 0000000..ff5e733
--- /dev/null
+++ b/src/runtime/runtime_mmap_test.go
@@ -0,0 +1,30 @@
+// Copyright 2016 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// +build darwin dragonfly freebsd linux nacl netbsd openbsd solaris
+
+package runtime_test
+
+import (
+       "runtime"
+       "runtime/internal/sys"
+       "testing"
+)
+
+// Test that the error value returned by mmap is positive, as that is
+// what the code in mem_bsd.go, mem_darwin.go, and mem_linux.go expects.
+// See the uses of ENOMEM in sysMap in those files.
+func TestMmapErrorSign(t *testing.T) {
+       p := runtime.Mmap(nil, ^uintptr(0)&^(sys.PhysPageSize-1), 0, runtime.MAP_ANON|runtime.MAP_PRIVATE, -1, 0)
+
+       // The runtime.mmap function is nosplit, but t.Errorf is not.
+       // Reset the pointer so that we don't get an "invalid stack
+       // pointer" error from t.Errorf if we call it.
+       v := uintptr(p)
+       p = nil
+
+       if v != runtime.ENOMEM {
+               t.Errorf("mmap = %v, want %v", v, runtime.ENOMEM)
+       }
+}

diff --git a/src/runtime/sys_linux_arm64.s b/src/runtime/sys_linux_arm64.s
index ca0e07aaa4cda043d976bbdc9ed6f6606f23be95..94c101a3d40cc61af4b708f7ecfb7f3847fecc36 100644 (file)
--- a/src/runtime/sys_linux_arm64.s
+++ b/src/runtime/sys_linux_arm64.s
@@ -269,6 +269,9 @@ TEXT runtime·mmap(SB),NOSPLIT,$-8
 
        MOVD    $SYS_mmap, R8
        SVC
+       CMN     $4095, R0
+       BCC     2(PC)
+       NEG     R0,R0
        MOVD    R0, ret+32(FP)
        RET
 

diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
index 6ccb38f90b65affe958bbb1599a806772ce4b2a2..26437ddde4ed506faff81a35b1955630fb75d944 100644 (file)
--- a/src/runtime/sys_linux_mips64x.s
+++ b/src/runtime/sys_linux_mips64x.s
@@ -168,6 +168,7 @@ TEXT runtime·mincore(SB),NOSPLIT,$-8-28
        MOVV    dst+16(FP), R6
        MOVV    $SYS_mincore, R2
        SYSCALL
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index ba410c51b64800cf4f615d19f8ec21e8d0af7722..d063e025a60ee4d32f2bbda5f2ca44ec9a7968f9 100644 (file)
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -153,6 +153,7 @@ TEXT runtime·mincore(SB),NOSPLIT|NOFRAME,$0-28
        MOVD    n+8(FP), R4
        MOVD    dst+16(FP), R5
        SYSCALL $SYS_mincore
+       NEG     R3              // caller expects negative errno
        MOVW    R3, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_nacl_386.s b/src/runtime/sys_nacl_386.s
index bf2d36ec8516c80c45f726db6870e73ec6b03352..e69a0b7bfedd343f420119fb5f659a302d7a0e5f 100644 (file)
--- a/src/runtime/sys_nacl_386.s
+++ b/src/runtime/sys_nacl_386.s
@@ -227,6 +227,9 @@ TEXT runtime·mmap(SB),NOSPLIT,$32
        LEAL    24(SP), AX
        MOVL    AX, 20(SP)
        NACL_SYSCALL(SYS_mmap)
+       CMPL    AX, $-4095
+       JNA     2(PC)
+       NEGL    AX
        MOVL    AX, ret+24(FP)
        RET