Commit b653c878 authored by Ian Lance Taylor's avatar Ian Lance Taylor

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: default avatarMichael Knyszek <mknyszek@google.com>
parent 6917b3c8
......@@ -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")
......
......@@ -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)
}
......
......@@ -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()
......
......@@ -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
......
......@@ -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) {
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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,$0
......
......@@ -104,7 +104,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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 $-1, AX
NEGL AX // caller expects negative errno
MOVL AX, ret+24(FP)
RET
......
......@@ -93,7 +93,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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 $-1, AX
NEGL AX // caller expects negative errno
MOVL AX, ret+12(FP)
RET
......
......@@ -93,7 +93,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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
......
......@@ -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 $-1, R2
MOVW R2, ret+24(FP)
RET
......
......@@ -83,7 +83,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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 $-1, AX
NEGL AX // caller expects negative errno
MOVL AX, ret+12(FP)
RET
......
......@@ -154,7 +154,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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
......
......@@ -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
......
......@@ -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 $-1, R0
NEG R0, R0
ok:
MOVW R0, ret+24(FP)
RET
......
......@@ -46,7 +46,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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 $-1, AX
NEGL AX // caller expects negative errno
MOVL AX, ret+12(FP)
RET
......
......@@ -123,7 +123,7 @@ TEXT runtime·read(SB),NOSPLIT,$-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
......
......@@ -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
......
......@@ -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
......
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