runtime: change read and write to return negative errno value

The internal read and write functions used to return -1 on error;
change them to return a negative errno value instead.
This will be used by later CLs in this series.

For most targets this is a simplification, although for ones that call
into libc it is a complication.

Updates #27707

Change-Id: Id02bf9487f03e7e88e4f2b85e899e986738697ad
Reviewed-on: https://go-review.googlesource.com/c/go/+/171823
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Michael Knyszek <mknyszek@google.com>

diff --git a/src/runtime/crash_unix_test.go b/src/runtime/crash_unix_test.go
index ce227feebd73737cf660faea178a1c091219bc5c..4be4962f907cf64aa60162c1bea8b3ecb78710ad 100644 (file)
--- a/src/runtime/crash_unix_test.go
+++ b/src/runtime/crash_unix_test.go
@@ -18,6 +18,7 @@ import (
        "strings"
        "syscall"
        "testing"
+       "unsafe"
 )
 
 // sigquit is the signal to send to kill a hanging testdata program.
@@ -33,6 +34,29 @@ func init() {
        }
 }
 
+func TestBadOpen(t *testing.T) {
+       // make sure we get the correct error code if open fails. Same for
+       // read/write/close on the resulting -1 fd. See issue 10052.
+       nonfile := []byte("/notreallyafile")
+       fd := runtime.Open(&nonfile[0], 0, 0)
+       if fd != -1 {
+               t.Errorf("open(%q)=%d, want -1", nonfile, fd)
+       }
+       var buf [32]byte
+       r := runtime.Read(-1, unsafe.Pointer(&buf[0]), int32(len(buf)))
+       if got, want := r, -int32(syscall.EBADF); got != want {
+               t.Errorf("read()=%d, want %d", got, want)
+       }
+       w := runtime.Write(^uintptr(0), unsafe.Pointer(&buf[0]), int32(len(buf)))
+       if got, want := w, -int32(syscall.EBADF); got != want {
+               t.Errorf("write()=%d, want %d", got, want)
+       }
+       c := runtime.Close(-1)
+       if c != -1 {
+               t.Errorf("close()=%d, want -1", c)
+       }
+}
+
 func TestCrashDumpsAllThreads(t *testing.T) {
        if *flagQuick {
                t.Skip("-quick")

diff --git a/src/runtime/os2_aix.go b/src/runtime/os2_aix.go
index 9f5c185bacd7a414f91443f611461c81a7b14d61..7f69d6d1e37cc445a2dc2bd3c9ebbeb1f3d586df 100644 (file)
--- a/src/runtime/os2_aix.go
+++ b/src/runtime/os2_aix.go
@@ -399,16 +399,23 @@ func write1(fd uintptr, p unsafe.Pointer, n int32) int32 {
        // Check the validity of g because without a g during
        // newosproc0.
        if _g_ != nil {
-               r, _ := syscall3(&libc_write, uintptr(fd), uintptr(p), uintptr(n))
+               r, errno := syscall3(&libc_write, uintptr(fd), uintptr(p), uintptr(n))
+               if int32(r) < 0 {
+                       return -int32(errno)
+               }
                return int32(r)
        }
+       // Note that in this case we can't return a valid errno value.
        return write2(fd, uintptr(p), n)
 
 }
 
 //go:nosplit
 func read(fd int32, p unsafe.Pointer, n int32) int32 {
-       r, _ := syscall3(&libc_read, uintptr(fd), uintptr(p), uintptr(n))
+       r, errno := syscall3(&libc_read, uintptr(fd), uintptr(p), uintptr(n))
+       if int32(r) < 0 {
+               return -int32(errno)
+       }
        return int32(r)
 }
 

diff --git a/src/runtime/os3_solaris.go b/src/runtime/os3_solaris.go
index cdec190de52abfe3270440bb3d5c003b0917a633..4ac191fab8eb65061c095ebeac48cfdd739cf220 100644 (file)
--- a/src/runtime/os3_solaris.go
+++ b/src/runtime/os3_solaris.go
@@ -447,7 +447,11 @@ func raiseproc(sig uint32) /* int32 */ {
 
 //go:nosplit
 func read(fd int32, buf unsafe.Pointer, nbyte int32) int32 {
-       return int32(sysvicall3(&libc_read, uintptr(fd), uintptr(buf), uintptr(nbyte)))
+       r1, err := sysvicall3Err(&libc_read, uintptr(fd), uintptr(buf), uintptr(nbyte))
+       if c := int32(r1); c >= 0 {
+               return c
+       }
+       return -int32(err)
 }
 
 //go:nosplit
@@ -511,7 +515,11 @@ func walltime1() (sec int64, nsec int32) {
 
 //go:nosplit
 func write1(fd uintptr, buf unsafe.Pointer, nbyte int32) int32 {
-       return int32(sysvicall3(&libc_write, uintptr(fd), uintptr(buf), uintptr(nbyte)))
+       r1, err := sysvicall3Err(&libc_write, fd, uintptr(buf), uintptr(nbyte))
+       if c := int32(r1); c >= 0 {
+               return c
+       }
+       return -int32(err)
 }
 
 func osyield1()

diff --git a/src/runtime/os_solaris.go b/src/runtime/os_solaris.go
index 989edb5dcdf1d9a484145f5bdef89ea939c232eb..d6c09156bd55df564499ecc647c75b9e04a552cc 100644 (file)
--- a/src/runtime/os_solaris.go
+++ b/src/runtime/os_solaris.go
@@ -122,6 +122,16 @@ func sysvicall2(fn *libcFunc, a1, a2 uintptr) uintptr {
 
 //go:nosplit
 func sysvicall3(fn *libcFunc, a1, a2, a3 uintptr) uintptr {
+       r1, _ := sysvicall3Err(fn, a1, a2, a3)
+       return r1
+}
+
+//go:nosplit
+//go:cgo_unsafe_args
+
+// sysvicall3Err returns both the system call result and the errno value.
+// This is used by sysicall3 and write1.
+func sysvicall3Err(fn *libcFunc, a1, a2, a3 uintptr) (r1, err uintptr) {
        // Leave caller's PC/SP around for traceback.
        gp := getg()
        var mp *m
@@ -146,7 +156,7 @@ func sysvicall3(fn *libcFunc, a1, a2, a3 uintptr) uintptr {
        if mp != nil {
                mp.libcallsp = 0
        }
-       return libcall.r1
+       return libcall.r1, libcall.err
 }
 
 //go:nosplit

diff --git a/src/runtime/runtime_test.go b/src/runtime/runtime_test.go
index ab7a03b2d1608edf554dfc6c93352e6992ddc4f4..26ae77456ae6d6148caa0b307cd5c832007b6f8f 100644 (file)
--- a/src/runtime/runtime_test.go
+++ b/src/runtime/runtime_test.go
@@ -290,32 +290,6 @@ func TestTrailingZero(t *testing.T) {
        }
 }
 
-func TestBadOpen(t *testing.T) {
-       if GOOS == "windows" || GOOS == "js" {
-               t.Skip("skipping OS that doesn't have open/read/write/close")
-       }
-       // make sure we get the correct error code if open fails. Same for
-       // read/write/close on the resulting -1 fd. See issue 10052.
-       nonfile := []byte("/notreallyafile")
-       fd := Open(&nonfile[0], 0, 0)
-       if fd != -1 {
-               t.Errorf("open(\"%s\")=%d, want -1", string(nonfile), fd)
-       }
-       var buf [32]byte
-       r := Read(-1, unsafe.Pointer(&buf[0]), int32(len(buf)))
-       if r != -1 {
-               t.Errorf("read()=%d, want -1", r)
-       }
-       w := Write(^uintptr(0), unsafe.Pointer(&buf[0]), int32(len(buf)))
-       if w != -1 {
-               t.Errorf("write()=%d, want -1", w)
-       }
-       c := Close(-1)
-       if c != -1 {
-               t.Errorf("close()=%d, want -1", c)
-       }
-}
-
 func TestAppendGrowth(t *testing.T) {
        var x []int64
        check := func(want int) {

diff --git a/src/runtime/stubs2.go b/src/runtime/stubs2.go
index cf2b12481252ecce529a1117dd57a127c1edd477..4a1a5cc3d90bb04c5266f20a27e9eb0e9725ee98 100644 (file)
--- a/src/runtime/stubs2.go
+++ b/src/runtime/stubs2.go
@@ -13,12 +13,17 @@ package runtime
 
 import "unsafe"
 
+// read calls the read system call.
+// It returns a non-negative number of bytes written or a negative errno value.
 func read(fd int32, p unsafe.Pointer, n int32) int32
+
 func closefd(fd int32) int32
 
 func exit(code int32)
 func usleep(usec uint32)
 
+// write calls the write system call.
+// It returns a non-negative number of bytes written or a negative errno value.
 //go:noescape
 func write1(fd uintptr, p unsafe.Pointer, n int32) int32
 

diff --git a/src/runtime/sys_darwin_386.s b/src/runtime/sys_darwin_386.s
index e653c54f614dc128778895c193ca06aad5f8e85b..bea804b8ddff30fb689f52677025a45c78c52bd2 100644 (file)
--- a/src/runtime/sys_darwin_386.s
+++ b/src/runtime/sys_darwin_386.s
@@ -64,6 +64,12 @@ TEXT runtime·read_trampoline(SB),NOSPLIT,$0
        MOVL    8(CX), AX               // arg 3 count
        MOVL    AX, 8(SP)
        CALL    libc_read(SB)
+       TESTL   AX, AX
+       JGE     noerr
+       CALL    libc_error(SB)
+       MOVL    (AX), AX
+       NEGL    AX                      // caller expects negative errno value
+noerr:
        MOVL    BP, SP
        POPL    BP
        RET
@@ -80,6 +86,12 @@ TEXT runtime·write_trampoline(SB),NOSPLIT,$0
        MOVL    8(CX), AX               // arg 3 count
        MOVL    AX, 8(SP)
        CALL    libc_write(SB)
+       TESTL   AX, AX
+       JGE     noerr
+       CALL    libc_error(SB)
+       MOVL    (AX), AX
+       NEGL    AX                      // caller expects negative errno value
+noerr:
        MOVL    BP, SP
        POPL    BP
        RET

diff --git a/src/runtime/sys_darwin_amd64.s b/src/runtime/sys_darwin_amd64.s
index 87c8db8c82dc49e48c8d0895b55011781759b8be..ea8cf1abb13c31169625af9d701868c999235672 100644 (file)
--- a/src/runtime/sys_darwin_amd64.s
+++ b/src/runtime/sys_darwin_amd64.s
@@ -46,6 +46,12 @@ TEXT runtime·read_trampoline(SB),NOSPLIT,$0
        MOVL    16(DI), DX              // arg 3 count
        MOVL    0(DI), DI               // arg 1 fd
        CALL    libc_read(SB)
+       TESTL   AX, AX
+       JGE     noerr
+       CALL    libc_error(SB)
+       MOVL    (AX), AX
+       NEGL    AX                      // caller expects negative errno value
+noerr:
        POPQ    BP
        RET
 
@@ -56,6 +62,12 @@ TEXT runtime·write_trampoline(SB),NOSPLIT,$0
        MOVL    16(DI), DX              // arg 3 count
        MOVQ    0(DI), DI               // arg 1 fd
        CALL    libc_write(SB)
+       TESTL   AX, AX
+       JGE     noerr
+       CALL    libc_error(SB)
+       MOVL    (AX), AX
+       NEGL    AX                      // caller expects negative errno value
+noerr:
        POPQ    BP
        RET
 

diff --git a/src/runtime/sys_darwin_arm.s b/src/runtime/sys_darwin_arm.s
index 996f8028a36b389ac4de6de9f814c9df0e139abc..84b0b0f5f4ccfe9816110b8cf30409e8de2bc9de 100644 (file)
--- a/src/runtime/sys_darwin_arm.s
+++ b/src/runtime/sys_darwin_arm.s
@@ -32,6 +32,13 @@ TEXT runtime·write_trampoline(SB),NOSPLIT,$0
        MOVW    8(R0), R2       // arg 3 count
        MOVW    0(R0), R0       // arg 1 fd
        BL      libc_write(SB)
+       MOVW    $-1, R1
+       CMP     R0, R1
+       BNE     noerr
+       BL      libc_error(SB)
+       MOVW    (R0), R0
+       RSB     $0, R0, R0      // caller expects negative errno value
+noerr:
        RET
 
 TEXT runtime·read_trampoline(SB),NOSPLIT,$0
@@ -39,6 +46,13 @@ TEXT runtime·read_trampoline(SB),NOSPLIT,$0
        MOVW    8(R0), R2       // arg 3 count
        MOVW    0(R0), R0       // arg 1 fd
        BL      libc_read(SB)
+       MOVW    $-1, R1
+       CMP     R0, R1
+       BNE     noerr
+       BL      libc_error(SB)
+       MOVW    (R0), R0
+       RSB     $0, R0, R0      // caller expects negative errno value
+noerr:
        RET
 
 TEXT runtime·pipe_trampoline(SB),NOSPLIT,$0

diff --git a/src/runtime/sys_darwin_arm64.s b/src/runtime/sys_darwin_arm64.s
index ac3ca74f6379773ab1a01710ea48d7b4741d94fb..8d39a0727fc7a11f2015935a6fdc24668ff7aff3 100644 (file)
--- a/src/runtime/sys_darwin_arm64.s
+++ b/src/runtime/sys_darwin_arm64.s
@@ -35,6 +35,13 @@ TEXT runtime·write_trampoline(SB),NOSPLIT,$0
        MOVW    16(R0), R2      // arg 3 count
        MOVW    0(R0), R0       // arg 1 fd
        BL      libc_write(SB)
+       MOVD    $-1, R1
+       CMP     R0, R1
+       BNE     noerr
+       BL      libc_error(SB)
+       MOVW    (R0), R0
+       NEG     R0, R0          // caller expects negative errno value
+noerr:
        RET
 
 TEXT runtime·read_trampoline(SB),NOSPLIT,$0
@@ -42,6 +49,13 @@ TEXT runtime·read_trampoline(SB),NOSPLIT,$0
        MOVW    16(R0), R2      // arg 3 count
        MOVW    0(R0), R0       // arg 1 fd
        BL      libc_read(SB)
+       MOVD    $-1, R1
+       CMP     R0, R1
+       BNE     noerr
+       BL      libc_error(SB)
+       MOVW    (R0), R0
+       NEG     R0, R0          // caller expects negative errno value
+noerr:
        RET
 
 TEXT runtime·pipe_trampoline(SB),NOSPLIT,$0

diff --git a/src/runtime/sys_dragonfly_amd64.s b/src/runtime/sys_dragonfly_amd64.s
index b3f9f1eb01885ce19801f7ab8fca20a065ae1020..68962d9e3054bb31837c685053feda65c7b0eee1 100644 (file)
--- a/src/runtime/sys_dragonfly_amd64.s
+++ b/src/runtime/sys_dragonfly_amd64.s
@@ -104,7 +104,7 @@ TEXT runtime·read(SB),NOSPLIT,$-8
        MOVL    $3, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 
@@ -130,7 +130,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-8
        MOVL    $4, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_freebsd_386.s b/src/runtime/sys_freebsd_386.s
index d8474546fb58d8eec16197ebf75f017a3fc916d7..48f64b9f8b6f28d9a356e9c13db145206c0f1010 100644 (file)
--- a/src/runtime/sys_freebsd_386.s
+++ b/src/runtime/sys_freebsd_386.s
@@ -93,7 +93,7 @@ TEXT runtime·read(SB),NOSPLIT,$-4
        MOVL    $3, AX
        INT     $0x80
        JAE     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+12(FP)
        RET
 
@@ -127,7 +127,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-4
        MOVL    $4, AX
        INT     $0x80
        JAE     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_freebsd_amd64.s b/src/runtime/sys_freebsd_amd64.s
index 7d6d7164f40c46b58b9c8844ccb2ef0163e20e84..d24ab1f643c27dc9aad355c4f85bb634e91d3cf0 100644 (file)
--- a/src/runtime/sys_freebsd_amd64.s
+++ b/src/runtime/sys_freebsd_amd64.s
@@ -93,7 +93,7 @@ TEXT runtime·read(SB),NOSPLIT,$-8
        MOVL    $3, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGQ    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 
@@ -128,7 +128,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-8
        MOVL    $4, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGQ    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_freebsd_arm.s b/src/runtime/sys_freebsd_arm.s
index 27b45888f42d0c19a2670980930911319e84b7d6..cdfecacfbc74f6866862a5688fb5525d3dd411ce 100644 (file)
--- a/src/runtime/sys_freebsd_arm.s
+++ b/src/runtime/sys_freebsd_arm.s
@@ -117,7 +117,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
        MOVW n+8(FP), R2        // arg 3 count
        MOVW $SYS_read, R7
        SWI $0
-       MOVW.CS $-1, R0
+       SUB.CS  $0, R0, R0      // caller expects negative errno
        MOVW    R0, ret+12(FP)
        RET
 
@@ -153,7 +153,7 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
        MOVW n+8(FP), R2        // arg 3 count
        MOVW $SYS_write, R7
        SWI $0
-       MOVW.CS $-1, R0
+       SUB.CS  $0, R0, R0      // caller expects negative errno
        MOVW    R0, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_linux_386.s b/src/runtime/sys_linux_386.s
index 2e4f66c55afc8a4fa88285642a65548d5d987fbe..4b440b13cbf37ee309e2666c09d7787f13d7a50b 100644 (file)
--- a/src/runtime/sys_linux_386.s
+++ b/src/runtime/sys_linux_386.s
@@ -115,9 +115,6 @@ TEXT runtime·write1(SB),NOSPLIT,$0
        MOVL    p+4(FP), CX
        MOVL    n+8(FP), DX
        INVOKE_SYSCALL
-       CMPL    AX, $0xfffff001
-       JLS     2(PC)
-       MOVL    $-1, AX
        MOVL    AX, ret+12(FP)
        RET
 
@@ -127,9 +124,6 @@ TEXT runtime·read(SB),NOSPLIT,$0
        MOVL    p+4(FP), CX
        MOVL    n+8(FP), DX
        INVOKE_SYSCALL
-       CMPL    AX, $0xfffff001
-       JLS     2(PC)
-       MOVL    $-1, AX
        MOVL    AX, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_linux_amd64.s b/src/runtime/sys_linux_amd64.s
index ae4d0ef060cfc029198f3e2487f415cf2c828755..0728d1766e2aa73d1d88c01a706928cf4d4cc4c6 100644 (file)
--- a/src/runtime/sys_linux_amd64.s
+++ b/src/runtime/sys_linux_amd64.s
@@ -97,9 +97,6 @@ TEXT runtime·write1(SB),NOSPLIT,$0-28
        MOVL    n+16(FP), DX
        MOVL    $SYS_write, AX
        SYSCALL
-       CMPQ    AX, $0xfffffffffffff001
-       JLS     2(PC)
-       MOVL    $-1, AX
        MOVL    AX, ret+24(FP)
        RET
 
@@ -109,9 +106,6 @@ TEXT runtime·read(SB),NOSPLIT,$0-28
        MOVL    n+16(FP), DX
        MOVL    $SYS_read, AX
        SYSCALL
-       CMPQ    AX, $0xfffffffffffff001
-       JLS     2(PC)
-       MOVL    $-1, AX
        MOVL    AX, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_linux_arm.s b/src/runtime/sys_linux_arm.s
index 047dfed4977fe42141c91976ce6c5bc06279ed33..23a66554ab4758f1d334224dee5371d30aed0e97 100644 (file)
--- a/src/runtime/sys_linux_arm.s
+++ b/src/runtime/sys_linux_arm.s
@@ -83,9 +83,6 @@ TEXT runtime·write1(SB),NOSPLIT,$0
        MOVW    n+8(FP), R2
        MOVW    $SYS_write, R7
        SWI     $0
-       MOVW    $0xfffff001, R1
-       CMP     R1, R0
-       MOVW.HI $-1, R0
        MOVW    R0, ret+12(FP)
        RET
 
@@ -95,9 +92,6 @@ TEXT runtime·read(SB),NOSPLIT,$0
        MOVW    n+8(FP), R2
        MOVW    $SYS_read, R7
        SWI     $0
-       MOVW    $0xfffff001, R1
-       CMP     R1, R0
-       MOVW.HI $-1, R0
        MOVW    R0, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_linux_arm64.s b/src/runtime/sys_linux_arm64.s
index d5ffe7fd579704013ad4fadf32c6d37fe615e7cf..5514a6be62d4d9aa7dcb4666f879ac57f5381e53 100644 (file)
--- a/src/runtime/sys_linux_arm64.s
+++ b/src/runtime/sys_linux_arm64.s
@@ -98,10 +98,6 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0-28
        MOVW    n+16(FP), R2
        MOVD    $SYS_write, R8
        SVC
-       CMN     $4095, R0
-       BCC     done
-       MOVW    $-1, R0
-done:
        MOVW    R0, ret+24(FP)
        RET
 
@@ -111,10 +107,6 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
        MOVW    n+16(FP), R2
        MOVD    $SYS_read, R8
        SVC
-       CMN     $4095, R0
-       BCC     done
-       MOVW    $-1, R0
-done:
        MOVW    R0, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_linux_mips64x.s b/src/runtime/sys_linux_mips64x.s
index b0cb0672faa49492433b054d8b68a8e1a13b6913..49459b0cece32338b6020f4489ae0407c60127f4 100644 (file)
--- a/src/runtime/sys_linux_mips64x.s
+++ b/src/runtime/sys_linux_mips64x.s
@@ -96,7 +96,7 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0-28
        MOVV    $SYS_write, R2
        SYSCALL
        BEQ     R7, 2(PC)
-       MOVW    $-1, R2
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+24(FP)
        RET
 
@@ -107,7 +107,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
        MOVV    $SYS_read, R2
        SYSCALL
        BEQ     R7, 2(PC)
-       MOVW    $-1, R2
+       SUBVU   R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_linux_mipsx.s b/src/runtime/sys_linux_mipsx.s
index 77f932f50aeb94ec3266388209629405c3ea44fa..3c405c264e19f0f2e2f7dc99e68b2094ce7611f0 100644 (file)
--- a/src/runtime/sys_linux_mipsx.s
+++ b/src/runtime/sys_linux_mipsx.s
@@ -95,7 +95,7 @@ TEXT runtime·write1(SB),NOSPLIT,$0-16
        MOVW    $SYS_write, R2
        SYSCALL
        BEQ     R7, 2(PC)
-       MOVW    $-1, R2
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+12(FP)
        RET
 
@@ -106,7 +106,7 @@ TEXT runtime·read(SB),NOSPLIT,$0-16
        MOVW    $SYS_read, R2
        SYSCALL
        BEQ     R7, 2(PC)
-       MOVW    $-1, R2
+       SUBU    R2, R0, R2      // caller expects negative errno
        MOVW    R2, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_linux_ppc64x.s b/src/runtime/sys_linux_ppc64x.s
index d4908a127cb64068287afae95a3c3ac857af3ef7..203ce089c1351b50c352e2abd76c40894f35f4fe 100644 (file)
--- a/src/runtime/sys_linux_ppc64x.s
+++ b/src/runtime/sys_linux_ppc64x.s
@@ -88,7 +88,7 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0-28
        MOVW    n+16(FP), R5
        SYSCALL $SYS_write
        BVC     2(PC)
-       MOVW    $-1, R3
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+24(FP)
        RET
 
@@ -98,7 +98,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
        MOVW    n+16(FP), R5
        SYSCALL $SYS_read
        BVC     2(PC)
-       MOVW    $-1, R3
+       NEG     R3      // caller expects negative errno
        MOVW    R3, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_linux_s390x.s b/src/runtime/sys_linux_s390x.s
index 01f408e70bfd4eb570f21c3dcaf965cfdd69ea14..df01271f7b5f30cf22b9e715444fa4f719429086 100644 (file)
--- a/src/runtime/sys_linux_s390x.s
+++ b/src/runtime/sys_linux_s390x.s
@@ -88,9 +88,6 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0-28
        MOVW    n+16(FP), R4
        MOVW    $SYS_write, R1
        SYSCALL
-       MOVD    $-4095, R3
-       CMPUBLT R2, R3, 2(PC)
-       MOVW    $-1, R2
        MOVW    R2, ret+24(FP)
        RET
 
@@ -100,9 +97,6 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0-28
        MOVW    n+16(FP), R4
        MOVW    $SYS_read, R1
        SYSCALL
-       MOVD    $-4095, R3
-       CMPUBLT R2, R3, 2(PC)
-       MOVW    $-1, R2
        MOVW    R2, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_netbsd_386.s b/src/runtime/sys_netbsd_386.s
index c882d1332b6ed8a463fac040a7aa184e862f4bae..7a542da526b22feb2039c780797c56aeb3de061a 100644 (file)
--- a/src/runtime/sys_netbsd_386.s
+++ b/src/runtime/sys_netbsd_386.s
@@ -83,7 +83,7 @@ TEXT runtime·read(SB),NOSPLIT,$-4
        MOVL    $SYS_read, AX
        INT     $0x80
        JAE     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+12(FP)
        RET
 
@@ -117,7 +117,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-4
        MOVL    $SYS_write, AX
        INT     $0x80
        JAE     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_netbsd_amd64.s b/src/runtime/sys_netbsd_amd64.s
index 0784b8445547d17a6d4ecbf84e14681bc53c6214..4d1d36f01bfa53ddbe6b471212181b09f0a7133b 100644 (file)
--- a/src/runtime/sys_netbsd_amd64.s
+++ b/src/runtime/sys_netbsd_amd64.s
@@ -154,7 +154,7 @@ TEXT runtime·read(SB),NOSPLIT,$-8
        MOVL    $SYS_read, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGQ    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 
@@ -189,7 +189,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-8
        MOVL    $SYS_write, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGQ    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_netbsd_arm.s b/src/runtime/sys_netbsd_arm.s
index ce2afc2d881ca7643728f4a9f38fca98abeaec2b..423982b1158b02d439246eda5fdb9b0755e7b063 100644 (file)
--- a/src/runtime/sys_netbsd_arm.s
+++ b/src/runtime/sys_netbsd_arm.s
@@ -92,7 +92,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
        MOVW p+4(FP), R1
        MOVW n+8(FP), R2
        SWI $SYS_read
-       MOVW.CS $-1, R0
+       SUB.CS  $0, R0, R0      // caller expects negative errno
        MOVW    R0, ret+12(FP)
        RET
 
@@ -125,7 +125,7 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
        MOVW    p+4(FP), R1     // arg 2 - buf
        MOVW    n+8(FP), R2     // arg 3 - nbyte
        SWI $SYS_write
-       MOVW.CS $-1, R0
+       SUB.CS  $0, R0, R0      // caller expects negative errno
        MOVW    R0, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_netbsd_arm64.s b/src/runtime/sys_netbsd_arm64.s
index ab0579772b36c13e5e8216f7658e2173a4e8229d..ccc34142aa34c87a6aefe809e6b6c5bb4e8492d4 100644 (file)
--- a/src/runtime/sys_netbsd_arm64.s
+++ b/src/runtime/sys_netbsd_arm64.s
@@ -145,7 +145,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
        MOVW    n+16(FP), R2            // arg 3 - count
        SVC     $SYS_read
        BCC     ok
-       MOVW    $-1, R0
+       NEG     R0, R0
 ok:
        MOVW    R0, ret+24(FP)
        RET
@@ -183,7 +183,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-8
        MOVW    n+16(FP), R2            // arg 3 - nbyte
        SVC     $SYS_write
        BCC     ok
-       MOVW    $-1, R0
+       NEG     R0, R0
 ok:
        MOVW    R0, ret+24(FP)
        RET

diff --git a/src/runtime/sys_openbsd_386.s b/src/runtime/sys_openbsd_386.s
index 1a216a572f265c526e73bc0b938ff1a079773d4f..9805a438025c6bc33255e166f896dcca77f1a5ef 100644 (file)
--- a/src/runtime/sys_openbsd_386.s
+++ b/src/runtime/sys_openbsd_386.s
@@ -46,7 +46,7 @@ TEXT runtime·read(SB),NOSPLIT,$-4
        MOVL    $3, AX
        INT     $0x80
        JAE     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+12(FP)
        RET
 
@@ -74,7 +74,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-4
        MOVL    $4, AX                  // sys_write
        INT     $0x80
        JAE     2(PC)
-       MOVL    $-1, AX
+       NEGL    AX                      // caller expects negative errno
        MOVL    AX, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_openbsd_amd64.s b/src/runtime/sys_openbsd_amd64.s
index 8bb2b265be5e34f25fdef88e6c875e563378e247..66526bff0de84c30cdb62a09a49b2f712cab60cb 100644 (file)
--- a/src/runtime/sys_openbsd_amd64.s
+++ b/src/runtime/sys_openbsd_amd64.s
@@ -123,7 +123,7 @@ TEXT runtime·read(SB),NOSPLIT,$-8
        MOVL    $3, AX
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGQ    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 
@@ -151,7 +151,7 @@ TEXT runtime·write1(SB),NOSPLIT,$-8
        MOVL    $4, AX                  // sys_write
        SYSCALL
        JCC     2(PC)
-       MOVL    $-1, AX
+       NEGQ    AX                      // caller expects negative errno
        MOVL    AX, ret+24(FP)
        RET
 

diff --git a/src/runtime/sys_openbsd_arm.s b/src/runtime/sys_openbsd_arm.s
index 16de1efd03bcb94843610bad680217c14ad8e274..3736451ba2ae3a1895997ee9094d3875aed28447 100644 (file)
--- a/src/runtime/sys_openbsd_arm.s
+++ b/src/runtime/sys_openbsd_arm.s
@@ -55,7 +55,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
        MOVW    n+8(FP), R2             // arg 3 - nbyte
        MOVW    $3, R12                 // sys_read
        SWI     $0
-       MOVW.CS $-1, R0
+       SUB.CS  $0, R0, R0      // caller expects negative errno
        MOVW    R0, ret+12(FP)
        RET
 
@@ -82,7 +82,7 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
        MOVW    n+8(FP), R2             // arg 3 - nbyte
        MOVW    $4, R12                 // sys_write
        SWI     $0
-       MOVW.CS $-1, R0
+       SUB.CS  $0, R0, R0      // caller expects negative errno
        MOVW    R0, ret+12(FP)
        RET
 

diff --git a/src/runtime/sys_openbsd_arm64.s b/src/runtime/sys_openbsd_arm64.s
index 66b4e89388a118f8ec1aba86e052dd73a34b9204..c8bf2d345e57068b03cecf35a7d1001c19b38f14 100644 (file)
--- a/src/runtime/sys_openbsd_arm64.s
+++ b/src/runtime/sys_openbsd_arm64.s
@@ -59,7 +59,7 @@ TEXT runtime·read(SB),NOSPLIT|NOFRAME,$0
        MOVD    $3, R8                  // sys_read
        SVC
        BCC     2(PC)
-       MOVW    $-1, R0
+       NEG     R0, R0
        MOVW    R0, ret+24(FP)
        RET
 
@@ -92,7 +92,7 @@ TEXT runtime·write1(SB),NOSPLIT|NOFRAME,$0
        MOVD    $4, R8                  // sys_write
        SVC
        BCC     2(PC)
-       MOVW    $-1, R0
+       NEG     R0, R0
        MOVW    R0, ret+24(FP)
        RET