[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

5 files changed, 24 insertions, 22 deletions

diff --git a/pkg/sentry/fsimpl/gofer/BUILD b/pkg/sentry/fsimpl/gofer/BUILD
index 807b6ed1f..6d5258a9b 100644
--- a/pkg/sentry/fsimpl/gofer/BUILD
+++ b/pkg/sentry/fsimpl/gofer/BUILD
@@ -51,6 +51,7 @@ go_library(
         "//pkg/fd",
         "//pkg/fdnotifier",
         "//pkg/fspath",
+        "//pkg/hostarch",
         "//pkg/log",
         "//pkg/p9",
         "//pkg/refs",
diff --git a/pkg/sentry/fsimpl/gofer/directory.go b/pkg/sentry/fsimpl/gofer/directory.go
index 9da01cba3..177e42649 100644
--- a/pkg/sentry/fsimpl/gofer/directory.go
+++ b/pkg/sentry/fsimpl/gofer/directory.go
@@ -20,6 +20,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/refsvfs2"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
@@ -28,7 +29,6 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 func (d *dentry) isDir() bool {
@@ -98,7 +98,7 @@ func (d *dentry) createSyntheticChildLocked(opts *createSyntheticOpts) {
 		mode:      uint32(opts.mode),
 		uid:       uint32(opts.kuid),
 		gid:       uint32(opts.kgid),
-		blockSize: usermem.PageSize, // arbitrary
+		blockSize: hostarch.PageSize, // arbitrary
 		atime:     now,
 		mtime:     now,
 		ctime:     now,
diff --git a/pkg/sentry/fsimpl/gofer/gofer.go b/pkg/sentry/fsimpl/gofer/gofer.go
index 692da02c1..a0c05231a 100644
--- a/pkg/sentry/fsimpl/gofer/gofer.go
+++ b/pkg/sentry/fsimpl/gofer/gofer.go
@@ -44,6 +44,7 @@ import (
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/p9"
 	refs_vfs1 "gvisor.dev/gvisor/pkg/refs"
@@ -60,7 +61,6 @@ import (
 	"gvisor.dev/gvisor/pkg/sync"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/unet"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // Name is the default filesystem name.
@@ -872,7 +872,7 @@ func (fs *filesystem) newDentry(ctx context.Context, file p9file, qid p9.QID, ma
 		mode:      uint32(attr.Mode),
 		uid:       uint32(fs.opts.dfltuid),
 		gid:       uint32(fs.opts.dfltgid),
-		blockSize: usermem.PageSize,
+		blockSize: hostarch.PageSize,
 		readFD:    -1,
 		writeFD:   -1,
 		mmapFD:    -1,
@@ -1217,8 +1217,8 @@ func (d *dentry) updateSizeLocked(newSize uint64) {
 	// so we can't race with Write or another truncate.)
 	d.dataMu.Unlock()
 	if d.size < oldSize {
-		oldpgend, _ := usermem.PageRoundUp(oldSize)
-		newpgend, _ := usermem.PageRoundUp(d.size)
+		oldpgend, _ := hostarch.PageRoundUp(oldSize)
+		newpgend, _ := hostarch.PageRoundUp(d.size)
 		if oldpgend != newpgend {
 			d.mapsMu.Lock()
 			d.mappings.Invalidate(memmap.MappableRange{newpgend, oldpgend}, memmap.InvalidateOpts{
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go
index 4f1ad0c88..47563538c 100644
--- a/pkg/sentry/fsimpl/gofer/regular_file.go
+++ b/pkg/sentry/fsimpl/gofer/regular_file.go
@@ -22,6 +22,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/log"
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/safemem"
@@ -291,8 +292,8 @@ func (fd *regularFileFD) writeCache(ctx context.Context, d *dentry, offset int64
 	}
 
 	// Remove touched pages from the cache.
-	pgstart := usermem.PageRoundDown(uint64(offset))
-	pgend, ok := usermem.PageRoundUp(uint64(offset + src.NumBytes()))
+	pgstart := hostarch.PageRoundDown(uint64(offset))
+	pgend, ok := hostarch.PageRoundUp(uint64(offset + src.NumBytes()))
 	if !ok {
 		return syserror.EINVAL
 	}
@@ -408,7 +409,7 @@ func (rw *dentryReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error)
 		switch {
 		case seg.Ok():
 			// Get internal mappings from the cache.
-			ims, err := mf.MapInternal(seg.FileRangeOf(seg.Range().Intersect(mr)), usermem.Read)
+			ims, err := mf.MapInternal(seg.FileRangeOf(seg.Range().Intersect(mr)), hostarch.Read)
 			if err != nil {
 				dataMuUnlock()
 				rw.d.handleMu.RUnlock()
@@ -434,9 +435,9 @@ func (rw *dentryReadWriter) ReadToBlocks(dsts safemem.BlockSeq) (uint64, error)
 			if fillCache {
 				// Read into the cache, then re-enter the loop to read from the
 				// cache.
-				gapEnd, _ := usermem.PageRoundUp(gapMR.End)
+				gapEnd, _ := hostarch.PageRoundUp(gapMR.End)
 				reqMR := memmap.MappableRange{
-					Start: usermem.PageRoundDown(gapMR.Start),
+					Start: hostarch.PageRoundDown(gapMR.Start),
 					End:   gapEnd,
 				}
 				optMR := gap.Range()
@@ -527,7 +528,7 @@ func (rw *dentryReadWriter) WriteFromBlocks(srcs safemem.BlockSeq) (uint64, erro
 		case seg.Ok():
 			// Get internal mappings from the cache.
 			segMR := seg.Range().Intersect(mr)
-			ims, err := mf.MapInternal(seg.FileRangeOf(segMR), usermem.Write)
+			ims, err := mf.MapInternal(seg.FileRangeOf(segMR), hostarch.Write)
 			if err != nil {
 				retErr = err
 				goto exitLoop
@@ -714,7 +715,7 @@ func (d *dentry) mayCachePages() bool {
 }
 
 // AddMapping implements memmap.Mappable.AddMapping.
-func (d *dentry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) error {
+func (d *dentry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar hostarch.AddrRange, offset uint64, writable bool) error {
 	d.mapsMu.Lock()
 	mapped := d.mappings.AddMapping(ms, ar, offset, writable)
 	// Do this unconditionally since whether we have a host FD can change
@@ -735,7 +736,7 @@ func (d *dentry) AddMapping(ctx context.Context, ms memmap.MappingSpace, ar user
 }
 
 // RemoveMapping implements memmap.Mappable.RemoveMapping.
-func (d *dentry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar usermem.AddrRange, offset uint64, writable bool) {
+func (d *dentry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar hostarch.AddrRange, offset uint64, writable bool) {
 	d.mapsMu.Lock()
 	unmapped := d.mappings.RemoveMapping(ms, ar, offset, writable)
 	for _, r := range unmapped {
@@ -759,12 +760,12 @@ func (d *dentry) RemoveMapping(ctx context.Context, ms memmap.MappingSpace, ar u
 }
 
 // CopyMapping implements memmap.Mappable.CopyMapping.
-func (d *dentry) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR usermem.AddrRange, offset uint64, writable bool) error {
+func (d *dentry) CopyMapping(ctx context.Context, ms memmap.MappingSpace, srcAR, dstAR hostarch.AddrRange, offset uint64, writable bool) error {
 	return d.AddMapping(ctx, ms, dstAR, offset, writable)
 }
 
 // Translate implements memmap.Mappable.Translate.
-func (d *dentry) Translate(ctx context.Context, required, optional memmap.MappableRange, at usermem.AccessType) ([]memmap.Translation, error) {
+func (d *dentry) Translate(ctx context.Context, required, optional memmap.MappableRange, at hostarch.AccessType) ([]memmap.Translation, error) {
 	d.handleMu.RLock()
 	if d.mmapFD >= 0 && !d.fs.opts.forcePageCache {
 		d.handleMu.RUnlock()
@@ -777,7 +778,7 @@ func (d *dentry) Translate(ctx context.Context, required, optional memmap.Mappab
 				Source: mr,
 				File:   &d.pf,
 				Offset: mr.Start,
-				Perms:  usermem.AnyAccess,
+				Perms:  hostarch.AnyAccess,
 			},
 		}, nil
 	}
@@ -786,7 +787,7 @@ func (d *dentry) Translate(ctx context.Context, required, optional memmap.Mappab
 
 	// Constrain translations to d.size (rounded up) to prevent translation to
 	// pages that may be concurrently truncated.
-	pgend, _ := usermem.PageRoundUp(d.size)
+	pgend, _ := hostarch.PageRoundUp(d.size)
 	var beyondEOF bool
 	if required.End > pgend {
 		if required.Start >= pgend {
@@ -811,7 +812,7 @@ func (d *dentry) Translate(ctx context.Context, required, optional memmap.Mappab
 		segMR := seg.Range().Intersect(optional)
 		// TODO(jamieliu): Make Translations writable even if writability is
 		// not required if already kept-dirty by another writable translation.
-		perms := usermem.AccessType{
+		perms := hostarch.AccessType{
 			Read:    true,
 			Execute: true,
 		}
@@ -954,7 +955,7 @@ func (d *dentryPlatformFile) DecRef(fr memmap.FileRange) {
 }
 
 // MapInternal implements memmap.File.MapInternal.
-func (d *dentryPlatformFile) MapInternal(fr memmap.FileRange, at usermem.AccessType) (safemem.BlockSeq, error) {
+func (d *dentryPlatformFile) MapInternal(fr memmap.FileRange, at hostarch.AccessType) (safemem.BlockSeq, error) {
 	d.handleMu.RLock()
 	defer d.handleMu.RUnlock()
 	return d.hostFileMapper.MapInternal(fr, int(d.mmapFD), at.Write)
diff --git a/pkg/sentry/fsimpl/gofer/save_restore.go b/pkg/sentry/fsimpl/gofer/save_restore.go
index c90071e4e..83e841a51 100644
--- a/pkg/sentry/fsimpl/gofer/save_restore.go
+++ b/pkg/sentry/fsimpl/gofer/save_restore.go
@@ -22,12 +22,12 @@ import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/fdnotifier"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/p9"
 	"gvisor.dev/gvisor/pkg/refsvfs2"
 	"gvisor.dev/gvisor/pkg/safemem"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserror"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 type saveRestoreContextID int
@@ -85,7 +85,7 @@ func (fs *filesystem) PrepareSave(ctx context.Context) error {
 func (fd *specialFileFD) savePipeData(ctx context.Context) error {
 	fd.bufMu.Lock()
 	defer fd.bufMu.Unlock()
-	var buf [usermem.PageSize]byte
+	var buf [hostarch.PageSize]byte
 	for {
 		n, err := fd.handle.readToBlocksAt(ctx, safemem.BlockSeqOf(safemem.BlockFromSafeSlice(buf[:])), ^uint64(0))
 		if n != 0 {