proc: show file flags in fdinfo

Currently, there is an attempt to print FD flags, but
they are not decoded into a number, so we see something like this:

/criu # cat /proc/self/fdinfo/0
flags: {%!o(bool=000false)}

Actually, fdinfo has to contain file flags.

Change-Id: Idcbb7db908067447eb9ae6f2c3cfb861f2be1a97
PiperOrigin-RevId: 206794498

2 files changed, 2 insertions, 45 deletions

diff --git a/pkg/sentry/syscalls/linux/flags.go b/pkg/sentry/syscalls/linux/flags.go
index b2e173f3e..e8db3e0de 100644
--- a/pkg/sentry/syscalls/linux/flags.go
+++ b/pkg/sentry/syscalls/linux/flags.go
@@ -17,7 +17,6 @@ package linux
 import (
 	"gvisor.googlesource.com/gvisor/pkg/abi/linux"
 	"gvisor.googlesource.com/gvisor/pkg/sentry/fs"
-	"gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
 )
 
 // flagsToPermissions returns a Permissions object from Linux flags.
@@ -35,48 +34,6 @@ func flagsToPermissions(mask uint) (p fs.PermMask) {
 	return
 }
 
-// fdFlagsToLinux converts a kernel.FDFlags object to a Linux representation.
-func fdFlagsToLinux(flags kernel.FDFlags) (mask uint) {
-	if flags.CloseOnExec {
-		mask |= linux.FD_CLOEXEC
-	}
-	return
-}
-
-// flagsToLinux converts a FileFlags object to a Linux representation.
-func flagsToLinux(flags fs.FileFlags) (mask uint) {
-	if flags.Direct {
-		mask |= linux.O_DIRECT
-	}
-	if flags.NonBlocking {
-		mask |= linux.O_NONBLOCK
-	}
-	if flags.Sync {
-		mask |= linux.O_SYNC
-	}
-	if flags.Append {
-		mask |= linux.O_APPEND
-	}
-	if flags.Directory {
-		mask |= linux.O_DIRECTORY
-	}
-	if flags.Async {
-		mask |= linux.O_ASYNC
-	}
-	if flags.LargeFile {
-		mask |= linux.O_LARGEFILE
-	}
-	switch {
-	case flags.Read && flags.Write:
-		mask |= linux.O_RDWR
-	case flags.Write:
-		mask |= linux.O_WRONLY
-	case flags.Read:
-		mask |= linux.O_RDONLY
-	}
-	return
-}
-
 // linuxToFlags converts linux file flags to a FileFlags object.
 func linuxToFlags(mask uint) (flags fs.FileFlags) {
 	return fs.FileFlags{
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go
index 2f28fbea6..692f11ed7 100644
--- a/pkg/sentry/syscalls/linux/sys_file.go
+++ b/pkg/sentry/syscalls/linux/sys_file.go
@@ -809,14 +809,14 @@ func Fcntl(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
 		}
 		return uintptr(fd), nil, nil
 	case linux.F_GETFD:
-		return uintptr(fdFlagsToLinux(flags)), nil, nil
+		return uintptr(flags.ToLinuxFDFlags()), nil, nil
 	case linux.F_SETFD:
 		flags := args[2].Uint()
 		t.FDMap().SetFlags(fd, kernel.FDFlags{
 			CloseOnExec: flags&syscall.FD_CLOEXEC != 0,
 		})
 	case linux.F_GETFL:
-		return uintptr(flagsToLinux(file.Flags())), nil, nil
+		return uintptr(file.Flags().ToLinux()), nil, nil
 	case linux.F_SETFL:
 		flags := uint(args[2].Uint())
 		file.SetFlags(linuxToSettableFlags(flags))