[syserror] Split usermem package

Split usermem package to help remove syserror dependency in go_marshal.
New hostarch package contains code not dependent on syserror.

PiperOrigin-RevId: 365651233

1 files changed, 27 insertions, 25 deletions

diff --git a/pkg/usermem/usermem.go b/pkg/usermem/usermem.go
index dc2571154..0d6d25e50 100644
--- a/pkg/usermem/usermem.go
+++ b/pkg/usermem/usermem.go
@@ -25,6 +25,8 @@ import (
 	"gvisor.dev/gvisor/pkg/gohacks"
 	"gvisor.dev/gvisor/pkg/safemem"
 	"gvisor.dev/gvisor/pkg/syserror"
+
+	"gvisor.dev/gvisor/pkg/hostarch"
 )
 
 // IO provides access to the contents of a virtual memory space.
@@ -37,7 +39,7 @@ type IO interface {
 	// any following locks in the lock order.
 	//
 	// Postconditions: CopyOut does not retain src.
-	CopyOut(ctx context.Context, addr Addr, src []byte, opts IOOpts) (int, error)
+	CopyOut(ctx context.Context, addr hostarch.Addr, src []byte, opts IOOpts) (int, error)
 
 	// CopyIn copies len(dst) bytes from the memory mapped at addr to dst.
 	// It returns the number of bytes copied. If the number of bytes copied is
@@ -47,7 +49,7 @@ type IO interface {
 	// any following locks in the lock order.
 	//
 	// Postconditions: CopyIn does not retain dst.
-	CopyIn(ctx context.Context, addr Addr, dst []byte, opts IOOpts) (int, error)
+	CopyIn(ctx context.Context, addr hostarch.Addr, dst []byte, opts IOOpts) (int, error)
 
 	// ZeroOut sets toZero bytes to 0, starting at addr. It returns the number
 	// of bytes zeroed. If the number of bytes zeroed is < toZero, it returns a
@@ -57,7 +59,7 @@ type IO interface {
 	// * The caller must not hold mm.MemoryManager.mappingMu or any
 	//   following locks in the lock order.
 	// * toZero >= 0.
-	ZeroOut(ctx context.Context, addr Addr, toZero int64, opts IOOpts) (int64, error)
+	ZeroOut(ctx context.Context, addr hostarch.Addr, toZero int64, opts IOOpts) (int64, error)
 
 	// CopyOutFrom copies ars.NumBytes() bytes from src to the memory mapped at
 	// ars. It returns the number of bytes copied, which may be less than the
@@ -72,7 +74,7 @@ type IO interface {
 	//   following locks in the lock order.
 	// * src.ReadToBlocks must not block on mm.MemoryManager.activeMu or
 	//   any preceding locks in the lock order.
-	CopyOutFrom(ctx context.Context, ars AddrRangeSeq, src safemem.Reader, opts IOOpts) (int64, error)
+	CopyOutFrom(ctx context.Context, ars hostarch.AddrRangeSeq, src safemem.Reader, opts IOOpts) (int64, error)
 
 	// CopyInTo copies ars.NumBytes() bytes from the memory mapped at ars to
 	// dst. It returns the number of bytes copied. CopyInTo may return a
@@ -86,7 +88,7 @@ type IO interface {
 	//   following locks in the lock order.
 	// * dst.WriteFromBlocks must not block on mm.MemoryManager.activeMu or
 	//   any preceding locks in the lock order.
-	CopyInTo(ctx context.Context, ars AddrRangeSeq, dst safemem.Writer, opts IOOpts) (int64, error)
+	CopyInTo(ctx context.Context, ars hostarch.AddrRangeSeq, dst safemem.Writer, opts IOOpts) (int64, error)
 
 	// TODO(jamieliu): The requirement that CopyOutFrom/CopyInTo call src/dst
 	// at most once, which is unnecessary in most cases, forces implementations
@@ -101,7 +103,7 @@ type IO interface {
 	// * The caller must not hold mm.MemoryManager.mappingMu or any
 	//   following locks in the lock order.
 	// * addr must be aligned to a 4-byte boundary.
-	SwapUint32(ctx context.Context, addr Addr, new uint32, opts IOOpts) (uint32, error)
+	SwapUint32(ctx context.Context, addr hostarch.Addr, new uint32, opts IOOpts) (uint32, error)
 
 	// CompareAndSwapUint32 atomically compares the uint32 value at addr to
 	// old; if they are equal, the value in memory is replaced by new. In
@@ -111,7 +113,7 @@ type IO interface {
 	// * The caller must not hold mm.MemoryManager.mappingMu or any
 	//   following locks in the lock order.
 	// * addr must be aligned to a 4-byte boundary.
-	CompareAndSwapUint32(ctx context.Context, addr Addr, old, new uint32, opts IOOpts) (uint32, error)
+	CompareAndSwapUint32(ctx context.Context, addr hostarch.Addr, old, new uint32, opts IOOpts) (uint32, error)
 
 	// LoadUint32 atomically loads the uint32 value at addr and returns it.
 	//
@@ -119,7 +121,7 @@ type IO interface {
 	// * The caller must not hold mm.MemoryManager.mappingMu or any
 	//   following locks in the lock order.
 	// * addr must be aligned to a 4-byte boundary.
-	LoadUint32(ctx context.Context, addr Addr, opts IOOpts) (uint32, error)
+	LoadUint32(ctx context.Context, addr hostarch.Addr, opts IOOpts) (uint32, error)
 }
 
 // IOOpts contains options applicable to all IO methods.
@@ -142,7 +144,7 @@ type IOOpts struct {
 type IOReadWriter struct {
 	Ctx  context.Context
 	IO   IO
-	Addr Addr
+	Addr hostarch.Addr
 	Opts IOOpts
 }
 
@@ -159,7 +161,7 @@ func (rw *IOReadWriter) Read(dst []byte) (int, error) {
 		rw.Addr = end
 	} else {
 		// Disallow wraparound.
-		rw.Addr = ^Addr(0)
+		rw.Addr = ^hostarch.Addr(0)
 		if err != nil {
 			err = syserror.EFAULT
 		}
@@ -175,7 +177,7 @@ func (rw *IOReadWriter) Write(src []byte) (int, error) {
 		rw.Addr = end
 	} else {
 		// Disallow wraparound.
-		rw.Addr = ^Addr(0)
+		rw.Addr = ^hostarch.Addr(0)
 		if err != nil {
 			err = syserror.EFAULT
 		}
@@ -197,7 +199,7 @@ const (
 //
 // Preconditions: Same as IO.CopyFromUser, plus:
 // * maxlen >= 0.
-func CopyStringIn(ctx context.Context, uio IO, addr Addr, maxlen int, opts IOOpts) (string, error) {
+func CopyStringIn(ctx context.Context, uio IO, addr hostarch.Addr, maxlen int, opts IOOpts) (string, error) {
 	initLen := maxlen
 	if initLen > copyStringMaxInitBufLen {
 		initLen = copyStringMaxInitBufLen
@@ -251,12 +253,12 @@ func CopyStringIn(ctx context.Context, uio IO, addr Addr, maxlen int, opts IOOpt
 // the maximum, it returns a non-nil error explaining why.
 //
 // Preconditions: Same as IO.CopyOut.
-func CopyOutVec(ctx context.Context, uio IO, ars AddrRangeSeq, src []byte, opts IOOpts) (int, error) {
+func CopyOutVec(ctx context.Context, uio IO, ars hostarch.AddrRangeSeq, src []byte, opts IOOpts) (int, error) {
 	var done int
 	for !ars.IsEmpty() && done < len(src) {
 		ar := ars.Head()
 		cplen := len(src) - done
-		if Addr(cplen) >= ar.Length() {
+		if hostarch.Addr(cplen) >= ar.Length() {
 			cplen = int(ar.Length())
 		}
 		n, err := uio.CopyOut(ctx, ar.Start, src[done:done+cplen], opts)
@@ -275,12 +277,12 @@ func CopyOutVec(ctx context.Context, uio IO, ars AddrRangeSeq, src []byte, opts
 // maximum, it returns a non-nil error explaining why.
 //
 // Preconditions: Same as IO.CopyIn.
-func CopyInVec(ctx context.Context, uio IO, ars AddrRangeSeq, dst []byte, opts IOOpts) (int, error) {
+func CopyInVec(ctx context.Context, uio IO, ars hostarch.AddrRangeSeq, dst []byte, opts IOOpts) (int, error) {
 	var done int
 	for !ars.IsEmpty() && done < len(dst) {
 		ar := ars.Head()
 		cplen := len(dst) - done
-		if Addr(cplen) >= ar.Length() {
+		if hostarch.Addr(cplen) >= ar.Length() {
 			cplen = int(ar.Length())
 		}
 		n, err := uio.CopyIn(ctx, ar.Start, dst[done:done+cplen], opts)
@@ -299,12 +301,12 @@ func CopyInVec(ctx context.Context, uio IO, ars AddrRangeSeq, dst []byte, opts I
 // maximum, it returns a non-nil error explaining why.
 //
 // Preconditions: Same as IO.ZeroOut.
-func ZeroOutVec(ctx context.Context, uio IO, ars AddrRangeSeq, toZero int64, opts IOOpts) (int64, error) {
+func ZeroOutVec(ctx context.Context, uio IO, ars hostarch.AddrRangeSeq, toZero int64, opts IOOpts) (int64, error) {
 	var done int64
 	for !ars.IsEmpty() && done < toZero {
 		ar := ars.Head()
 		cplen := toZero - done
-		if Addr(cplen) >= ar.Length() {
+		if hostarch.Addr(cplen) >= ar.Length() {
 			cplen = int64(ar.Length())
 		}
 		n, err := uio.ZeroOut(ctx, ar.Start, cplen, opts)
@@ -352,7 +354,7 @@ func isASCIIWhitespace(b byte) bool {
 // - CopyInt32StringsInVec returns EINVAL if ars.NumBytes() == 0.
 //
 // Preconditions: Same as CopyInVec.
-func CopyInt32StringsInVec(ctx context.Context, uio IO, ars AddrRangeSeq, dsts []int32, opts IOOpts) (int64, error) {
+func CopyInt32StringsInVec(ctx context.Context, uio IO, ars hostarch.AddrRangeSeq, dsts []int32, opts IOOpts) (int64, error) {
 	if len(dsts) == 0 {
 		return 0, nil
 	}
@@ -403,7 +405,7 @@ func CopyInt32StringsInVec(ctx context.Context, uio IO, ars AddrRangeSeq, dsts [
 
 // CopyInt32StringInVec is equivalent to CopyInt32StringsInVec, but copies at
 // most one int32.
-func CopyInt32StringInVec(ctx context.Context, uio IO, ars AddrRangeSeq, dst *int32, opts IOOpts) (int64, error) {
+func CopyInt32StringInVec(ctx context.Context, uio IO, ars hostarch.AddrRangeSeq, dst *int32, opts IOOpts) (int64, error) {
 	dsts := [1]int32{*dst}
 	n, err := CopyInt32StringsInVec(ctx, uio, ars, dsts[:], opts)
 	*dst = dsts[0]
@@ -413,7 +415,7 @@ func CopyInt32StringInVec(ctx context.Context, uio IO, ars AddrRangeSeq, dst *in
 // IOSequence holds arguments to IO methods.
 type IOSequence struct {
 	IO    IO
-	Addrs AddrRangeSeq
+	Addrs hostarch.AddrRangeSeq
 	Opts  IOOpts
 }
 
@@ -444,28 +446,28 @@ func (s IOSequence) NumBytes() int64 {
 
 // DropFirst returns a copy of s with s.Addrs.DropFirst(n).
 //
-// Preconditions: Same as AddrRangeSeq.DropFirst.
+// Preconditions: Same as hostarch.AddrRangeSeq.DropFirst.
 func (s IOSequence) DropFirst(n int) IOSequence {
 	return IOSequence{s.IO, s.Addrs.DropFirst(n), s.Opts}
 }
 
 // DropFirst64 returns a copy of s with s.Addrs.DropFirst64(n).
 //
-// Preconditions: Same as AddrRangeSeq.DropFirst64.
+// Preconditions: Same as hostarch.AddrRangeSeq.DropFirst64.
 func (s IOSequence) DropFirst64(n int64) IOSequence {
 	return IOSequence{s.IO, s.Addrs.DropFirst64(n), s.Opts}
 }
 
 // TakeFirst returns a copy of s with s.Addrs.TakeFirst(n).
 //
-// Preconditions: Same as AddrRangeSeq.TakeFirst.
+// Preconditions: Same as hostarch.AddrRangeSeq.TakeFirst.
 func (s IOSequence) TakeFirst(n int) IOSequence {
 	return IOSequence{s.IO, s.Addrs.TakeFirst(n), s.Opts}
 }
 
 // TakeFirst64 returns a copy of s with s.Addrs.TakeFirst64(n).
 //
-// Preconditions: Same as AddrRangeSeq.TakeFirst64.
+// Preconditions: Same as hostarch.AddrRangeSeq.TakeFirst64.
 func (s IOSequence) TakeFirst64(n int64) IOSequence {
 	return IOSequence{s.IO, s.Addrs.TakeFirst64(n), s.Opts}
 }