[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

10 files changed, 42 insertions, 35 deletions

diff --git a/pkg/sentry/fs/proc/BUILD b/pkg/sentry/fs/proc/BUILD
index b8b2281a8..7af7e0b45 100644
--- a/pkg/sentry/fs/proc/BUILD
+++ b/pkg/sentry/fs/proc/BUILD
@@ -30,6 +30,7 @@ go_library(
     deps = [
         "//pkg/abi/linux",
         "//pkg/context",
+        "//pkg/hostarch",
         "//pkg/log",
         "//pkg/sentry/fs",
         "//pkg/sentry/fs/fsutil",
diff --git a/pkg/sentry/fs/proc/exec_args.go b/pkg/sentry/fs/proc/exec_args.go
index e6171dd1d..24426b225 100644
--- a/pkg/sentry/fs/proc/exec_args.go
+++ b/pkg/sentry/fs/proc/exec_args.go
@@ -21,6 +21,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
@@ -113,7 +114,7 @@ func (f *execArgFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequen
 	defer m.DecUsers(ctx)
 
 	// Figure out the bounds of the exec arg we are trying to read.
-	var execArgStart, execArgEnd usermem.Addr
+	var execArgStart, execArgEnd hostarch.Addr
 	switch f.arg {
 	case cmdlineExecArg:
 		execArgStart, execArgEnd = m.ArgvStart(), m.ArgvEnd()
@@ -172,8 +173,8 @@ func (f *execArgFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequen
 			// https://elixir.bootlin.com/linux/v4.20/source/fs/proc/base.c#L208
 			// we'll return one page total between argv and envp because of the
 			// above page restrictions.
-			if lengthEnvv > usermem.PageSize-len(buf) {
-				lengthEnvv = usermem.PageSize - len(buf)
+			if lengthEnvv > hostarch.PageSize-len(buf) {
+				lengthEnvv = hostarch.PageSize - len(buf)
 			}
 			// Make a new buffer to fit the whole thing
 			tmp := make([]byte, length+lengthEnvv)
diff --git a/pkg/sentry/fs/proc/inode.go b/pkg/sentry/fs/proc/inode.go
index d2859a4c2..78132f7a5 100644
--- a/pkg/sentry/fs/proc/inode.go
+++ b/pkg/sentry/fs/proc/inode.go
@@ -17,13 +17,13 @@ package proc
 import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/device"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/mm"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // LINT.IfChange
@@ -125,7 +125,7 @@ func newProcInode(ctx context.Context, iops fs.InodeOperations, msrc *fs.MountSo
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      typ,
 	}
 	if t != nil {
diff --git a/pkg/sentry/fs/proc/meminfo.go b/pkg/sentry/fs/proc/meminfo.go
index 91617267d..7d975d333 100644
--- a/pkg/sentry/fs/proc/meminfo.go
+++ b/pkg/sentry/fs/proc/meminfo.go
@@ -19,10 +19,10 @@ import (
 	"fmt"
 
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/seqfile"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/usage"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // LINT.IfChange
@@ -53,7 +53,7 @@ func (d *meminfoData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle)
 	anon := snapshot.Anonymous + snapshot.Tmpfs
 	file := snapshot.PageCache + snapshot.Mapped
 	// We don't actually have active/inactive LRUs, so just make up numbers.
-	activeFile := (file / 2) &^ (usermem.PageSize - 1)
+	activeFile := (file / 2) &^ (hostarch.PageSize - 1)
 	inactiveFile := file - activeFile
 
 	var buf bytes.Buffer
diff --git a/pkg/sentry/fs/proc/net.go b/pkg/sentry/fs/proc/net.go
index 203cfa061..91c35eea9 100644
--- a/pkg/sentry/fs/proc/net.go
+++ b/pkg/sentry/fs/proc/net.go
@@ -23,6 +23,7 @@ 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/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/seqfile"
@@ -35,7 +36,6 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/socket/unix/transport"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/tcpip/header"
-	"gvisor.dev/gvisor/pkg/usermem"
 )
 
 // LINT.IfChange
@@ -367,10 +367,10 @@ func (n *netRoute) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([]
 		)
 		if len(rt.GatewayAddr) == header.IPv4AddressSize {
 			flags |= linux.RTF_GATEWAY
-			gw = usermem.ByteOrder.Uint32(rt.GatewayAddr)
+			gw = hostarch.ByteOrder.Uint32(rt.GatewayAddr)
 		}
 		if len(rt.DstAddr) == header.IPv4AddressSize {
-			prefix = usermem.ByteOrder.Uint32(rt.DstAddr)
+			prefix = hostarch.ByteOrder.Uint32(rt.DstAddr)
 		}
 		l := fmt.Sprintf(
 			"%s\t%08X\t%08X\t%04X\t%d\t%d\t%d\t%08X\t%d\t%d\t%d",
@@ -520,7 +520,7 @@ func networkToHost16(n uint16) uint16 {
 	// binary.BigEndian.Uint16() require a read of binary.BigEndian and an
 	// interface method call, defeating inlining.
 	buf := [2]byte{byte(n >> 8 & 0xff), byte(n & 0xff)}
-	return usermem.ByteOrder.Uint16(buf[:])
+	return hostarch.ByteOrder.Uint16(buf[:])
 }
 
 func writeInetAddr(w io.Writer, family int, i linux.SockAddr) {
@@ -542,14 +542,14 @@ func writeInetAddr(w io.Writer, family int, i linux.SockAddr) {
 		// __be32 which is a typedef for an unsigned int, and is printed with
 		// %X. This means that for a little-endian machine, Linux prints the
 		// least-significant byte of the address first. To emulate this, we first
-		// invert the byte order for the address using usermem.ByteOrder.Uint32,
+		// invert the byte order for the address using hostarch.ByteOrder.Uint32,
 		// which makes it have the equivalent encoding to a __be32 on a little
 		// endian machine. Note that this operation is a no-op on a big endian
 		// machine. Then similar to Linux, we format it with %X, which will print
 		// the most-significant byte of the __be32 address first, which is now
 		// actually the least-significant byte of the original address in
 		// linux.SockAddrInet.Addr on little endian machines, due to the conversion.
-		addr := usermem.ByteOrder.Uint32(a.Addr[:])
+		addr := hostarch.ByteOrder.Uint32(a.Addr[:])
 
 		fmt.Fprintf(w, "%08X:%04X ", addr, port)
 	case linux.AF_INET6:
@@ -559,10 +559,10 @@ func writeInetAddr(w io.Writer, family int, i linux.SockAddr) {
 		}
 
 		port := networkToHost16(a.Port)
-		addr0 := usermem.ByteOrder.Uint32(a.Addr[0:4])
-		addr1 := usermem.ByteOrder.Uint32(a.Addr[4:8])
-		addr2 := usermem.ByteOrder.Uint32(a.Addr[8:12])
-		addr3 := usermem.ByteOrder.Uint32(a.Addr[12:16])
+		addr0 := hostarch.ByteOrder.Uint32(a.Addr[0:4])
+		addr1 := hostarch.ByteOrder.Uint32(a.Addr[4:8])
+		addr2 := hostarch.ByteOrder.Uint32(a.Addr[8:12])
+		addr3 := hostarch.ByteOrder.Uint32(a.Addr[12:16])
 		fmt.Fprintf(w, "%08X%08X%08X%08X:%04X ", addr0, addr1, addr2, addr3, port)
 	}
 }
diff --git a/pkg/sentry/fs/proc/seqfile/BUILD b/pkg/sentry/fs/proc/seqfile/BUILD
index 21338d912..713b81e08 100644
--- a/pkg/sentry/fs/proc/seqfile/BUILD
+++ b/pkg/sentry/fs/proc/seqfile/BUILD
@@ -9,6 +9,7 @@ go_library(
     deps = [
         "//pkg/abi/linux",
         "//pkg/context",
+        "//pkg/hostarch",
         "//pkg/sentry/fs",
         "//pkg/sentry/fs/fsutil",
         "//pkg/sentry/fs/proc/device",
diff --git a/pkg/sentry/fs/proc/seqfile/seqfile.go b/pkg/sentry/fs/proc/seqfile/seqfile.go
index 6121f0e95..b01688b1d 100644
--- a/pkg/sentry/fs/proc/seqfile/seqfile.go
+++ b/pkg/sentry/fs/proc/seqfile/seqfile.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/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/device"
@@ -131,7 +132,7 @@ func NewSeqFileInode(ctx context.Context, source SeqSource, msrc *fs.MountSource
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      fs.SpecialFile,
 	}
 	return fs.NewInode(ctx, iops, msrc, sattr)
diff --git a/pkg/sentry/fs/proc/sys_net.go b/pkg/sentry/fs/proc/sys_net.go
index bbe282c03..1d09afdd7 100644
--- a/pkg/sentry/fs/proc/sys_net.go
+++ b/pkg/sentry/fs/proc/sys_net.go
@@ -21,6 +21,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/device"
@@ -76,7 +77,7 @@ func newTCPMemInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack, dir
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      fs.SpecialFile,
 	}
 	return fs.NewInode(ctx, tm, msrc, sattr)
@@ -136,7 +137,7 @@ func (f *tcpMemFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSequen
 	f.tcpMemInode.mu.Lock()
 	defer f.tcpMemInode.mu.Unlock()
 
-	src = src.TakeFirst(usermem.PageSize - 1)
+	src = src.TakeFirst(hostarch.PageSize - 1)
 	size, err := readSize(f.tcpMemInode.dir, f.tcpMemInode.s)
 	if err != nil {
 		return 0, err
@@ -192,7 +193,7 @@ func newTCPSackInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack) *f
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      fs.SpecialFile,
 	}
 	return fs.NewInode(ctx, ts, msrc, sattr)
@@ -264,7 +265,7 @@ func (f *tcpSackFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSeque
 
 	// Only consider size of one memory page for input for performance reasons.
 	// We are only reading if it's zero or not anyway.
-	src = src.TakeFirst(usermem.PageSize - 1)
+	src = src.TakeFirst(hostarch.PageSize - 1)
 
 	var v int32
 	n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
@@ -294,7 +295,7 @@ func newTCPRecoveryInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      fs.SpecialFile,
 	}
 	return fs.NewInode(ctx, ts, msrc, sattr)
@@ -354,7 +355,7 @@ func (f *tcpRecoveryFile) Write(ctx context.Context, _ *fs.File, src usermem.IOS
 	if src.NumBytes() == 0 {
 		return 0, nil
 	}
-	src = src.TakeFirst(usermem.PageSize - 1)
+	src = src.TakeFirst(hostarch.PageSize - 1)
 
 	var v int32
 	n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
@@ -413,7 +414,7 @@ func newIPForwardingInode(ctx context.Context, msrc *fs.MountSource, s inet.Stac
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      fs.SpecialFile,
 	}
 	return fs.NewInode(ctx, ipf, msrc, sattr)
@@ -486,7 +487,7 @@ func (f *ipForwardingFile) Write(ctx context.Context, _ *fs.File, src usermem.IO
 
 	// Only consider size of one memory page for input for performance reasons.
 	// We are only reading if it's zero or not anyway.
-	src = src.TakeFirst(usermem.PageSize - 1)
+	src = src.TakeFirst(hostarch.PageSize - 1)
 
 	var v int32
 	n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
@@ -524,7 +525,7 @@ func newPortRangeInode(ctx context.Context, msrc *fs.MountSource, s inet.Stack)
 	sattr := fs.StableAttr{
 		DeviceID:  device.ProcDevice.DeviceID(),
 		InodeID:   device.ProcDevice.NextIno(),
-		BlockSize: usermem.PageSize,
+		BlockSize: hostarch.PageSize,
 		Type:      fs.SpecialFile,
 	}
 	return fs.NewInode(ctx, ipf, msrc, sattr)
@@ -589,7 +590,7 @@ func (pf *portRangeFile) Write(ctx context.Context, _ *fs.File, src usermem.IOSe
 
 	// Only consider size of one memory page for input for performance
 	// reasons.
-	src = src.TakeFirst(usermem.PageSize - 1)
+	src = src.TakeFirst(hostarch.PageSize - 1)
 
 	ports := make([]int32, 2)
 	n, err := usermem.CopyInt32StringsInVec(ctx, src.IO, src.Addrs, ports, src.Opts)
diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go
index f43d6c221..ae5ed25f9 100644
--- a/pkg/sentry/fs/proc/task.go
+++ b/pkg/sentry/fs/proc/task.go
@@ -23,6 +23,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/fs/proc/device"
@@ -469,7 +470,7 @@ func (m *memDataFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequen
 	defer mm.DecUsers(ctx)
 	// Buffer the read data because of MM locks
 	buf := make([]byte, dst.NumBytes())
-	n, readErr := mm.CopyIn(ctx, usermem.Addr(offset), buf, usermem.IOOpts{IgnorePermissions: true})
+	n, readErr := mm.CopyIn(ctx, hostarch.Addr(offset), buf, usermem.IOOpts{IgnorePermissions: true})
 	if n > 0 {
 		if _, err := dst.CopyOut(ctx, buf[:n]); err != nil {
 			return 0, syserror.EFAULT
@@ -632,7 +633,7 @@ func (s *taskStatData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle)
 			rss = mm.ResidentSetSize()
 		}
 	})
-	fmt.Fprintf(&buf, "%d %d ", vss, rss/usermem.PageSize)
+	fmt.Fprintf(&buf, "%d %d ", vss, rss/hostarch.PageSize)
 
 	// rsslim.
 	fmt.Fprintf(&buf, "%d ", s.t.ThreadGroup().Limits().Get(limits.Rss).Cur)
@@ -684,7 +685,7 @@ func (s *statmData) ReadSeqFileData(ctx context.Context, h seqfile.SeqHandle) ([
 	})
 
 	var buf bytes.Buffer
-	fmt.Fprintf(&buf, "%d %d 0 0 0 0 0\n", vss/usermem.PageSize, rss/usermem.PageSize)
+	fmt.Fprintf(&buf, "%d %d 0 0 0 0 0\n", vss/hostarch.PageSize, rss/hostarch.PageSize)
 
 	return []seqfile.SeqData{{Buf: buf.Bytes(), Handle: (*statmData)(nil)}}, 0
 }
@@ -939,8 +940,8 @@ func (f *auxvecFile) Read(ctx context.Context, _ *fs.File, dst usermem.IOSequenc
 
 	buf := make([]byte, size)
 	for i, e := range auxv {
-		usermem.ByteOrder.PutUint64(buf[16*i:], e.Key)
-		usermem.ByteOrder.PutUint64(buf[16*i+8:], uint64(e.Value))
+		hostarch.ByteOrder.PutUint64(buf[16*i:], e.Key)
+		hostarch.ByteOrder.PutUint64(buf[16*i+8:], uint64(e.Value))
 	}
 
 	n, err := dst.CopyOut(ctx, buf[offset:])
@@ -1020,7 +1021,7 @@ func (f *oomScoreAdjFile) Write(ctx context.Context, _ *fs.File, src usermem.IOS
 	}
 
 	// Limit input size so as not to impact performance if input size is large.
-	src = src.TakeFirst(usermem.PageSize - 1)
+	src = src.TakeFirst(hostarch.PageSize - 1)
 
 	var v int32
 	n, err := usermem.CopyInt32StringInVec(ctx, src.IO, src.Addrs, &v, src.Opts)
diff --git a/pkg/sentry/fs/proc/uid_gid_map.go b/pkg/sentry/fs/proc/uid_gid_map.go
index 2bc9485d8..30d5ad4cf 100644
--- a/pkg/sentry/fs/proc/uid_gid_map.go
+++ b/pkg/sentry/fs/proc/uid_gid_map.go
@@ -21,6 +21,7 @@ import (
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
+	"gvisor.dev/gvisor/pkg/hostarch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/fs/fsutil"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
@@ -132,7 +133,7 @@ func (imfo *idMapFileOperations) Write(ctx context.Context, file *fs.File, src u
 	// the system page size, and the write must be performed at the start of
 	// the file ..." - user_namespaces(7)
 	srclen := src.NumBytes()
-	if srclen >= usermem.PageSize || offset != 0 {
+	if srclen >= hostarch.PageSize || offset != 0 {
 		return 0, syserror.EINVAL
 	}
 	b := make([]byte, srclen)