Enable stat syscall support on arm64.

x86 and arm64 use a different stat struct in Linux
kernel, so the stat() syscall implementation has
to handle the file stat data separately.

Signed-off-by: Haibo Xu <haibo.xu@arm.com>
Change-Id: If3986e915a667362257a54e7fbbcc1fe18951015
COPYBARA_INTEGRATE_REVIEW=https://github.com/google/gvisor/pull/1493 from xiaobo55x:stat f15a216d9297eb9a96d2c483d396a9919145d7fa
PiperOrigin-RevId: 290274287

1 files changed, 0 insertions, 51 deletions

diff --git a/pkg/sentry/syscalls/linux/sys_stat.go b/pkg/sentry/syscalls/linux/sys_stat.go
index 5556bc276..69b17b799 100644
--- a/pkg/sentry/syscalls/linux/sys_stat.go
+++ b/pkg/sentry/syscalls/linux/sys_stat.go
@@ -16,7 +16,6 @@ package linux
 
 import (
 	"gvisor.dev/gvisor/pkg/abi/linux"
-	"gvisor.dev/gvisor/pkg/binary"
 	"gvisor.dev/gvisor/pkg/sentry/arch"
 	"gvisor.dev/gvisor/pkg/sentry/fs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
@@ -125,56 +124,6 @@ func fstat(t *kernel.Task, f *fs.File, statAddr usermem.Addr) error {
 	return copyOutStat(t, statAddr, f.Dirent.Inode.StableAttr, uattr)
 }
 
-// copyOutStat copies the attributes (sattr, uattr) to the struct stat at
-// address dst in t's address space. It encodes the stat struct to bytes
-// manually, as stat() is a very common syscall for many applications, and
-// t.CopyObjectOut has noticeable performance impact due to its many slice
-// allocations and use of reflection.
-func copyOutStat(t *kernel.Task, dst usermem.Addr, sattr fs.StableAttr, uattr fs.UnstableAttr) error {
-	b := t.CopyScratchBuffer(int(linux.SizeOfStat))[:0]
-
-	// Dev (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(sattr.DeviceID))
-	// Ino (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(sattr.InodeID))
-	// Nlink (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uattr.Links)
-	// Mode (uint32)
-	b = binary.AppendUint32(b, usermem.ByteOrder, sattr.Type.LinuxType()|uint32(uattr.Perms.LinuxMode()))
-	// UID (uint32)
-	b = binary.AppendUint32(b, usermem.ByteOrder, uint32(uattr.Owner.UID.In(t.UserNamespace()).OrOverflow()))
-	// GID (uint32)
-	b = binary.AppendUint32(b, usermem.ByteOrder, uint32(uattr.Owner.GID.In(t.UserNamespace()).OrOverflow()))
-	// Padding (uint32)
-	b = binary.AppendUint32(b, usermem.ByteOrder, 0)
-	// Rdev (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(linux.MakeDeviceID(sattr.DeviceFileMajor, sattr.DeviceFileMinor)))
-	// Size (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(uattr.Size))
-	// Blksize (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(sattr.BlockSize))
-	// Blocks (uint64)
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(uattr.Usage/512))
-
-	// ATime
-	atime := uattr.AccessTime.Timespec()
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(atime.Sec))
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(atime.Nsec))
-
-	// MTime
-	mtime := uattr.ModificationTime.Timespec()
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(mtime.Sec))
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(mtime.Nsec))
-
-	// CTime
-	ctime := uattr.StatusChangeTime.Timespec()
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(ctime.Sec))
-	b = binary.AppendUint64(b, usermem.ByteOrder, uint64(ctime.Nsec))
-
-	_, err := t.CopyOutBytes(dst, b)
-	return err
-}
-
 // Statx implements linux syscall statx(2).
 func Statx(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
 	fd := args[0].Int()