[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

4 files changed, 29 insertions, 26 deletions

diff --git a/pkg/sentry/fsimpl/fuse/BUILD b/pkg/sentry/fsimpl/fuse/BUILD
index 155c0f56d..3a4777fbe 100644
--- a/pkg/sentry/fsimpl/fuse/BUILD
+++ b/pkg/sentry/fsimpl/fuse/BUILD
@@ -46,6 +46,7 @@ go_library(
     deps = [
         "//pkg/abi/linux",
         "//pkg/context",
+        "//pkg/hostarch",
         "//pkg/log",
         "//pkg/marshal",
         "//pkg/refs",
@@ -75,6 +76,7 @@ go_test(
     library = ":fuse",
     deps = [
         "//pkg/abi/linux",
+        "//pkg/hostarch",
         "//pkg/marshal",
         "//pkg/sentry/fsimpl/testutil",
         "//pkg/sentry/kernel",
diff --git a/pkg/sentry/fsimpl/fuse/read_write.go b/pkg/sentry/fsimpl/fuse/read_write.go
index 23ce91849..66ea889f9 100644
--- a/pkg/sentry/fsimpl/fuse/read_write.go
+++ b/pkg/sentry/fsimpl/fuse/read_write.go
@@ -20,11 +20,11 @@ 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/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/syserror"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // ReadInPages sends FUSE_READ requests for the size after round it up to
@@ -43,10 +43,10 @@ func (fs *filesystem) ReadInPages(ctx context.Context, fd *regularFileFD, off ui
 	}
 
 	// Round up to a multiple of page size.
-	readSize, _ := usermem.PageRoundUp(uint64(size))
+	readSize, _ := hostarch.PageRoundUp(uint64(size))
 
 	// One request cannnot exceed either maxRead or maxPages.
-	maxPages := fs.conn.maxRead >> usermem.PageShift
+	maxPages := fs.conn.maxRead >> hostarch.PageShift
 	if maxPages > uint32(fs.conn.maxPages) {
 		maxPages = uint32(fs.conn.maxPages)
 	}
@@ -54,9 +54,9 @@ func (fs *filesystem) ReadInPages(ctx context.Context, fd *regularFileFD, off ui
 	var outs [][]byte
 	var sizeRead uint32
 
-	// readSize is a multiple of usermem.PageSize.
+	// readSize is a multiple of hostarch.PageSize.
 	// Always request bytes as a multiple of pages.
-	pagesRead, pagesToRead := uint32(0), uint32(readSize>>usermem.PageShift)
+	pagesRead, pagesToRead := uint32(0), uint32(readSize>>hostarch.PageShift)
 
 	// Reuse the same struct for unmarshalling to avoid unnecessary memory allocation.
 	in := linux.FUSEReadIn{
@@ -76,8 +76,8 @@ func (fs *filesystem) ReadInPages(ctx context.Context, fd *regularFileFD, off ui
 			pagesCanRead = maxPages
 		}
 
-		in.Offset = off + (uint64(pagesRead) << usermem.PageShift)
-		in.Size = pagesCanRead << usermem.PageShift
+		in.Offset = off + (uint64(pagesRead) << hostarch.PageShift)
+		in.Size = pagesCanRead << hostarch.PageShift
 
 		// TODO(gvisor.dev/issue/3247): support async read.
 
@@ -159,7 +159,7 @@ func (fs *filesystem) Write(ctx context.Context, fd *regularFileFD, off uint64,
 	}
 
 	// One request cannnot exceed either maxWrite or maxPages.
-	maxWrite := uint32(fs.conn.maxPages) << usermem.PageShift
+	maxWrite := uint32(fs.conn.maxPages) << hostarch.PageShift
 	if maxWrite > fs.conn.maxWrite {
 		maxWrite = fs.conn.maxWrite
 	}
@@ -188,8 +188,8 @@ func (fs *filesystem) Write(ctx context.Context, fd *regularFileFD, off uint64,
 		// Limit the write size to one page.
 		// Note that the bigWrites flag is obsolete,
 		// latest libfuse always sets it on.
-		if !fs.conn.bigWrites && toWrite > usermem.PageSize {
-			toWrite = usermem.PageSize
+		if !fs.conn.bigWrites && toWrite > hostarch.PageSize {
+			toWrite = hostarch.PageSize
 		}
 
 		// Limit the write size to maxWrite.
diff --git a/pkg/sentry/fsimpl/fuse/request_response.go b/pkg/sentry/fsimpl/fuse/request_response.go
index 10fb9d7d2..8a72489fa 100644
--- a/pkg/sentry/fsimpl/fuse/request_response.go
+++ b/pkg/sentry/fsimpl/fuse/request_response.go
@@ -19,10 +19,10 @@ import (
 
 	"golang.org/x/sys/unix"
 	"gvisor.dev/gvisor/pkg/abi/linux"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/marshal"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // fuseInitRes is a variable-length wrapper of linux.FUSEInitOut. The FUSE
@@ -45,29 +45,29 @@ func (r *fuseInitRes) UnmarshalBytes(src []byte) {
 	out := &r.initOut
 
 	// Introduced before FUSE kernel version 7.13.
-	out.Major = uint32(usermem.ByteOrder.Uint32(src[:4]))
+	out.Major = uint32(hostarch.ByteOrder.Uint32(src[:4]))
 	src = src[4:]
-	out.Minor = uint32(usermem.ByteOrder.Uint32(src[:4]))
+	out.Minor = uint32(hostarch.ByteOrder.Uint32(src[:4]))
 	src = src[4:]
-	out.MaxReadahead = uint32(usermem.ByteOrder.Uint32(src[:4]))
+	out.MaxReadahead = uint32(hostarch.ByteOrder.Uint32(src[:4]))
 	src = src[4:]
-	out.Flags = uint32(usermem.ByteOrder.Uint32(src[:4]))
+	out.Flags = uint32(hostarch.ByteOrder.Uint32(src[:4]))
 	src = src[4:]
-	out.MaxBackground = uint16(usermem.ByteOrder.Uint16(src[:2]))
+	out.MaxBackground = uint16(hostarch.ByteOrder.Uint16(src[:2]))
 	src = src[2:]
-	out.CongestionThreshold = uint16(usermem.ByteOrder.Uint16(src[:2]))
+	out.CongestionThreshold = uint16(hostarch.ByteOrder.Uint16(src[:2]))
 	src = src[2:]
-	out.MaxWrite = uint32(usermem.ByteOrder.Uint32(src[:4]))
+	out.MaxWrite = uint32(hostarch.ByteOrder.Uint32(src[:4]))
 	src = src[4:]
 
 	// Introduced in FUSE kernel version 7.23.
 	if len(src) >= 4 {
-		out.TimeGran = uint32(usermem.ByteOrder.Uint32(src[:4]))
+		out.TimeGran = uint32(hostarch.ByteOrder.Uint32(src[:4]))
 		src = src[4:]
 	}
 	// Introduced in FUSE kernel version 7.28.
 	if len(src) >= 2 {
-		out.MaxPages = uint16(usermem.ByteOrder.Uint16(src[:2]))
+		out.MaxPages = uint16(hostarch.ByteOrder.Uint16(src[:2]))
 		src = src[2:]
 	}
 	_ = src // Remove unused warning.
diff --git a/pkg/sentry/fsimpl/fuse/utils_test.go b/pkg/sentry/fsimpl/fuse/utils_test.go
index 2c0cc0f4e..b0bab0066 100644
--- a/pkg/sentry/fsimpl/fuse/utils_test.go
+++ b/pkg/sentry/fsimpl/fuse/utils_test.go
@@ -24,7 +24,8 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/vfs"
-	"gvisor.dev/gvisor/pkg/usermem"
+
+	"gvisor.dev/gvisor/pkg/hostarch"
 )
 
 func setup(t *testing.T) *testutil.System {
@@ -82,12 +83,12 @@ func (t *testPayload) SizeBytes() int {
 
 // MarshalBytes implements marshal.Marshallable.MarshalBytes.
 func (t *testPayload) MarshalBytes(dst []byte) {
-	usermem.ByteOrder.PutUint32(dst[:4], t.data)
+	hostarch.ByteOrder.PutUint32(dst[:4], t.data)
 }
 
 // UnmarshalBytes implements marshal.Marshallable.UnmarshalBytes.
 func (t *testPayload) UnmarshalBytes(src []byte) {
-	*t = testPayload{data: usermem.ByteOrder.Uint32(src[:4])}
+	*t = testPayload{data: hostarch.ByteOrder.Uint32(src[:4])}
 }
 
 // Packed implements marshal.Marshallable.Packed.
@@ -106,17 +107,17 @@ func (t *testPayload) UnmarshalUnsafe(src []byte) {
 }
 
 // CopyOutN implements marshal.Marshallable.CopyOutN.
-func (t *testPayload) CopyOutN(task marshal.CopyContext, addr usermem.Addr, limit int) (int, error) {
+func (t *testPayload) CopyOutN(task marshal.CopyContext, addr hostarch.Addr, limit int) (int, error) {
 	panic("not implemented")
 }
 
 // CopyOut implements marshal.Marshallable.CopyOut.
-func (t *testPayload) CopyOut(task marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (t *testPayload) CopyOut(task marshal.CopyContext, addr hostarch.Addr) (int, error) {
 	panic("not implemented")
 }
 
 // CopyIn implements marshal.Marshallable.CopyIn.
-func (t *testPayload) CopyIn(task marshal.CopyContext, addr usermem.Addr) (int, error) {
+func (t *testPayload) CopyIn(task marshal.CopyContext, addr hostarch.Addr) (int, error) {
 	panic("not implemented")
 }