summaryrefslogtreecommitdiffhomepage
path: root/pkg/sentry/syscalls
diff options
context:
space:
mode:
Diffstat (limited to 'pkg/sentry/syscalls')
-rw-r--r--pkg/sentry/syscalls/linux/BUILD1
-rw-r--r--pkg/sentry/syscalls/linux/linux64.go2
-rw-r--r--pkg/sentry/syscalls/linux/sys_file.go5
-rw-r--r--pkg/sentry/syscalls/linux/sys_read.go33
-rw-r--r--pkg/sentry/syscalls/linux/sys_signal.go77
-rw-r--r--pkg/sentry/syscalls/linux/sys_socket.go2
-rw-r--r--pkg/sentry/syscalls/linux/sys_splice.go115
-rw-r--r--pkg/sentry/syscalls/linux/sys_time.go39
-rw-r--r--pkg/sentry/syscalls/linux/sys_utsname.go6
9 files changed, 194 insertions, 86 deletions
diff --git a/pkg/sentry/syscalls/linux/BUILD b/pkg/sentry/syscalls/linux/BUILD
index 33a40b9c6..e76ee27d2 100644
--- a/pkg/sentry/syscalls/linux/BUILD
+++ b/pkg/sentry/syscalls/linux/BUILD
@@ -74,6 +74,7 @@ go_library(
"//pkg/sentry/kernel/pipe",
"//pkg/sentry/kernel/sched",
"//pkg/sentry/kernel/shm",
+ "//pkg/sentry/kernel/signalfd",
"//pkg/sentry/kernel/time",
"//pkg/sentry/limits",
"//pkg/sentry/memmap",
diff --git a/pkg/sentry/syscalls/linux/linux64.go b/pkg/sentry/syscalls/linux/linux64.go
index 2f77d587b..72c383537 100644
--- a/pkg/sentry/syscalls/linux/linux64.go
+++ b/pkg/sentry/syscalls/linux/linux64.go
@@ -19,4 +19,4 @@ const (
_LINUX_SYSNAME = "Linux"
_LINUX_RELEASE = "4.4"
_LINUX_VERSION = "#1 SMP Sun Jan 10 15:06:54 PST 2016"
-)
+) \ No newline at end of file
diff --git a/pkg/sentry/syscalls/linux/sys_file.go b/pkg/sentry/syscalls/linux/sys_file.go
index 2e00a91ce..b9a8e3e21 100644
--- a/pkg/sentry/syscalls/linux/sys_file.go
+++ b/pkg/sentry/syscalls/linux/sys_file.go
@@ -1423,9 +1423,6 @@ func unlinkAt(t *kernel.Task, dirFD int32, addr usermem.Addr) error {
if err != nil {
return err
}
- if dirPath {
- return syserror.ENOENT
- }
return fileOpAt(t, dirFD, path, func(root *fs.Dirent, d *fs.Dirent, name string, _ uint) error {
if !fs.IsDir(d.Inode.StableAttr) {
@@ -1436,7 +1433,7 @@ func unlinkAt(t *kernel.Task, dirFD int32, addr usermem.Addr) error {
return err
}
- return d.Remove(t, root, name)
+ return d.Remove(t, root, name, dirPath)
})
}
diff --git a/pkg/sentry/syscalls/linux/sys_read.go b/pkg/sentry/syscalls/linux/sys_read.go
index 3ab54271c..cd31e0649 100644
--- a/pkg/sentry/syscalls/linux/sys_read.go
+++ b/pkg/sentry/syscalls/linux/sys_read.go
@@ -72,6 +72,39 @@ func Read(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallC
return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "read", file)
}
+// Readahead implements readahead(2).
+func Readahead(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ offset := args[1].Int64()
+ size := args[2].SizeT()
+
+ file := t.GetFile(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Check that the file is readable.
+ if !file.Flags().Read {
+ return 0, nil, syserror.EBADF
+ }
+
+ // Check that the size is valid.
+ if int(size) < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Check that the offset is legitimate.
+ if offset < 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Return EINVAL; if the underlying file type does not support readahead,
+ // then Linux will return EINVAL to indicate as much. In the future, we
+ // may extend this function to actually support readahead hints.
+ return 0, nil, syserror.EINVAL
+}
+
// Pread64 implements linux syscall pread64(2).
func Pread64(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
fd := args[0].Int()
diff --git a/pkg/sentry/syscalls/linux/sys_signal.go b/pkg/sentry/syscalls/linux/sys_signal.go
index 0104a94c0..fb6efd5d8 100644
--- a/pkg/sentry/syscalls/linux/sys_signal.go
+++ b/pkg/sentry/syscalls/linux/sys_signal.go
@@ -20,7 +20,10 @@ import (
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/arch"
+ "gvisor.dev/gvisor/pkg/sentry/fs"
"gvisor.dev/gvisor/pkg/sentry/kernel"
+ "gvisor.dev/gvisor/pkg/sentry/kernel/signalfd"
+ "gvisor.dev/gvisor/pkg/sentry/usermem"
"gvisor.dev/gvisor/pkg/syserror"
)
@@ -506,3 +509,77 @@ func RestartSyscall(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kerne
t.Debugf("Restart block missing in restart_syscall(2). Did ptrace inject a return value of ERESTART_RESTARTBLOCK?")
return 0, nil, syserror.EINTR
}
+
+// sharedSignalfd is shared between the two calls.
+func sharedSignalfd(t *kernel.Task, fd int32, sigset usermem.Addr, sigsetsize uint, flags int32) (uintptr, *kernel.SyscallControl, error) {
+ // Copy in the signal mask.
+ mask, err := copyInSigSet(t, sigset, sigsetsize)
+ if err != nil {
+ return 0, nil, err
+ }
+
+ // Always check for valid flags, even if not creating.
+ if flags&^(linux.SFD_NONBLOCK|linux.SFD_CLOEXEC) != 0 {
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Is this a change to an existing signalfd?
+ //
+ // The spec indicates that this should adjust the mask.
+ if fd != -1 {
+ file := t.GetFile(fd)
+ if file == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer file.DecRef()
+
+ // Is this a signalfd?
+ if s, ok := file.FileOperations.(*signalfd.SignalOperations); ok {
+ s.SetMask(mask)
+ return 0, nil, nil
+ }
+
+ // Not a signalfd.
+ return 0, nil, syserror.EINVAL
+ }
+
+ // Create a new file.
+ file, err := signalfd.New(t, mask)
+ if err != nil {
+ return 0, nil, err
+ }
+ defer file.DecRef()
+
+ // Set appropriate flags.
+ file.SetFlags(fs.SettableFileFlags{
+ NonBlocking: flags&linux.SFD_NONBLOCK != 0,
+ })
+
+ // Create a new descriptor.
+ fd, err = t.NewFDFrom(0, file, kernel.FDFlags{
+ CloseOnExec: flags&linux.SFD_CLOEXEC != 0,
+ })
+ if err != nil {
+ return 0, nil, err
+ }
+
+ // Done.
+ return uintptr(fd), nil, nil
+}
+
+// Signalfd implements the linux syscall signalfd(2).
+func Signalfd(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ sigset := args[1].Pointer()
+ sigsetsize := args[2].SizeT()
+ return sharedSignalfd(t, fd, sigset, sigsetsize, 0)
+}
+
+// Signalfd4 implements the linux syscall signalfd4(2).
+func Signalfd4(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
+ fd := args[0].Int()
+ sigset := args[1].Pointer()
+ sigsetsize := args[2].SizeT()
+ flags := args[3].Int()
+ return sharedSignalfd(t, fd, sigset, sigsetsize, flags)
+}
diff --git a/pkg/sentry/syscalls/linux/sys_socket.go b/pkg/sentry/syscalls/linux/sys_socket.go
index 3bac4d90d..b5a72ce63 100644
--- a/pkg/sentry/syscalls/linux/sys_socket.go
+++ b/pkg/sentry/syscalls/linux/sys_socket.go
@@ -531,7 +531,7 @@ func SetSockOpt(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sy
return 0, nil, syserror.ENOTSOCK
}
- if optLen <= 0 {
+ if optLen < 0 {
return 0, nil, syserror.EINVAL
}
if optLen > maxOptLen {
diff --git a/pkg/sentry/syscalls/linux/sys_splice.go b/pkg/sentry/syscalls/linux/sys_splice.go
index 17e3dde1f..9f705ebca 100644
--- a/pkg/sentry/syscalls/linux/sys_splice.go
+++ b/pkg/sentry/syscalls/linux/sys_splice.go
@@ -29,9 +29,8 @@ func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonB
total int64
n int64
err error
- ch chan struct{}
- inW bool
- outW bool
+ inCh chan struct{}
+ outCh chan struct{}
)
for opts.Length > 0 {
n, err = fs.Splice(t, outFile, inFile, opts)
@@ -43,35 +42,33 @@ func doSplice(t *kernel.Task, outFile, inFile *fs.File, opts fs.SpliceOpts, nonB
break
}
- // Are we a registered waiter?
- if ch == nil {
- ch = make(chan struct{}, 1)
- }
- if !inW && !inFile.Flags().NonBlocking {
- w, _ := waiter.NewChannelEntry(ch)
- inFile.EventRegister(&w, EventMaskRead)
- defer inFile.EventUnregister(&w)
- inW = true // Registered.
- } else if !outW && !outFile.Flags().NonBlocking {
- w, _ := waiter.NewChannelEntry(ch)
- outFile.EventRegister(&w, EventMaskWrite)
- defer outFile.EventUnregister(&w)
- outW = true // Registered.
- }
-
- // Was anything registered? If no, everything is non-blocking.
- if !inW && !outW {
- break
- }
-
- if (!inW || inFile.Readiness(EventMaskRead) != 0) && (!outW || outFile.Readiness(EventMaskWrite) != 0) {
- // Something became ready, try again without blocking.
- continue
+ // Note that the blocking behavior here is a bit different than the
+ // normal pattern. Because we need to have both data to read and data
+ // to write simultaneously, we actually explicitly block on both of
+ // these cases in turn before returning to the splice operation.
+ if inFile.Readiness(EventMaskRead) == 0 {
+ if inCh == nil {
+ inCh = make(chan struct{}, 1)
+ inW, _ := waiter.NewChannelEntry(inCh)
+ inFile.EventRegister(&inW, EventMaskRead)
+ defer inFile.EventUnregister(&inW)
+ continue // Need to refresh readiness.
+ }
+ if err = t.Block(inCh); err != nil {
+ break
+ }
}
-
- // Block until there's data.
- if err = t.Block(ch); err != nil {
- break
+ if outFile.Readiness(EventMaskWrite) == 0 {
+ if outCh == nil {
+ outCh = make(chan struct{}, 1)
+ outW, _ := waiter.NewChannelEntry(outCh)
+ outFile.EventRegister(&outW, EventMaskWrite)
+ defer outFile.EventUnregister(&outW)
+ continue // Need to refresh readiness.
+ }
+ if err = t.Block(outCh); err != nil {
+ break
+ }
}
}
@@ -91,22 +88,29 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
}
// Get files.
+ inFile := t.GetFile(inFD)
+ if inFile == nil {
+ return 0, nil, syserror.EBADF
+ }
+ defer inFile.DecRef()
+
+ if !inFile.Flags().Read {
+ return 0, nil, syserror.EBADF
+ }
+
outFile := t.GetFile(outFD)
if outFile == nil {
return 0, nil, syserror.EBADF
}
defer outFile.DecRef()
- inFile := t.GetFile(inFD)
- if inFile == nil {
+ if !outFile.Flags().Write {
return 0, nil, syserror.EBADF
}
- defer inFile.DecRef()
- // Verify that the outfile Append flag is not set. Note that fs.Splice
- // itself validates that the output file is writable.
+ // Verify that the outfile Append flag is not set.
if outFile.Flags().Append {
- return 0, nil, syserror.EBADF
+ return 0, nil, syserror.EINVAL
}
// Verify that we have a regular infile. This is a requirement; the
@@ -142,7 +146,7 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
Length: count,
SrcOffset: true,
SrcStart: offset,
- }, false)
+ }, outFile.Flags().NonBlocking)
// Copy out the new offset.
if _, err := t.CopyOut(offsetAddr, n+offset); err != nil {
@@ -152,7 +156,7 @@ func Sendfile(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
// Send data using splice.
n, err = doSplice(t, outFile, inFile, fs.SpliceOpts{
Length: count,
- }, false)
+ }, outFile.Flags().NonBlocking)
}
// We can only pass a single file to handleIOError, so pick inFile
@@ -174,12 +178,6 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
return 0, nil, syserror.EINVAL
}
- // Only non-blocking is meaningful. Note that unlike in Linux, this
- // flag is applied consistently. We will have either fully blocking or
- // non-blocking behavior below, regardless of the underlying files
- // being spliced to. It's unclear if this is a bug or not yet.
- nonBlocking := (flags & linux.SPLICE_F_NONBLOCK) != 0
-
// Get files.
outFile := t.GetFile(outFD)
if outFile == nil {
@@ -193,6 +191,13 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
}
defer inFile.DecRef()
+ // The operation is non-blocking if anything is non-blocking.
+ //
+ // N.B. This is a rather simplistic heuristic that avoids some
+ // poor edge case behavior since the exact semantics here are
+ // underspecified and vary between versions of Linux itself.
+ nonBlock := inFile.Flags().NonBlocking || outFile.Flags().NonBlocking || (flags&linux.SPLICE_F_NONBLOCK != 0)
+
// Construct our options.
//
// Note that exactly one of the underlying buffers must be a pipe. We
@@ -240,17 +245,17 @@ func Splice(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
if inOffset != 0 || outOffset != 0 {
return 0, nil, syserror.ESPIPE
}
- default:
- return 0, nil, syserror.EINVAL
- }
- // We may not refer to the same pipe; otherwise it's a continuous loop.
- if inFile.Dirent.Inode.StableAttr.InodeID == outFile.Dirent.Inode.StableAttr.InodeID {
+ // We may not refer to the same pipe; otherwise it's a continuous loop.
+ if inFile.Dirent.Inode.StableAttr.InodeID == outFile.Dirent.Inode.StableAttr.InodeID {
+ return 0, nil, syserror.EINVAL
+ }
+ default:
return 0, nil, syserror.EINVAL
}
// Splice data.
- n, err := doSplice(t, outFile, inFile, opts, nonBlocking)
+ n, err := doSplice(t, outFile, inFile, opts, nonBlock)
// See above; inFile is chosen arbitrarily here.
return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "splice", inFile)
@@ -268,9 +273,6 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo
return 0, nil, syserror.EINVAL
}
- // Only non-blocking is meaningful.
- nonBlocking := (flags & linux.SPLICE_F_NONBLOCK) != 0
-
// Get files.
outFile := t.GetFile(outFD)
if outFile == nil {
@@ -294,11 +296,14 @@ func Tee(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallCo
return 0, nil, syserror.EINVAL
}
+ // The operation is non-blocking if anything is non-blocking.
+ nonBlock := inFile.Flags().NonBlocking || outFile.Flags().NonBlocking || (flags&linux.SPLICE_F_NONBLOCK != 0)
+
// Splice data.
n, err := doSplice(t, outFile, inFile, fs.SpliceOpts{
Length: count,
Dup: true,
- }, nonBlocking)
+ }, nonBlock)
// See above; inFile is chosen arbitrarily here.
return uintptr(n), nil, handleIOError(t, n != 0, err, kernel.ERESTARTSYS, "tee", inFile)
diff --git a/pkg/sentry/syscalls/linux/sys_time.go b/pkg/sentry/syscalls/linux/sys_time.go
index 4b3f043a2..b887fa9d7 100644
--- a/pkg/sentry/syscalls/linux/sys_time.go
+++ b/pkg/sentry/syscalls/linux/sys_time.go
@@ -15,6 +15,7 @@
package linux
import (
+ "fmt"
"time"
"gvisor.dev/gvisor/pkg/abi/linux"
@@ -228,41 +229,35 @@ func clockNanosleepFor(t *kernel.Task, c ktime.Clock, dur time.Duration, rem use
timer.Destroy()
- var remaining time.Duration
- // Did we just block for the entire duration?
- if err == syserror.ETIMEDOUT {
- remaining = 0
- } else {
- remaining = dur - after.Sub(start)
+ switch err {
+ case syserror.ETIMEDOUT:
+ // Slept for entire timeout.
+ return nil
+ case syserror.ErrInterrupted:
+ // Interrupted.
+ remaining := dur - after.Sub(start)
if remaining < 0 {
remaining = time.Duration(0)
}
- }
- // Copy out remaining time.
- if err != nil && rem != usermem.Addr(0) {
- timeleft := linux.NsecToTimespec(remaining.Nanoseconds())
- if err := copyTimespecOut(t, rem, &timeleft); err != nil {
- return err
+ // Copy out remaining time.
+ if rem != 0 {
+ timeleft := linux.NsecToTimespec(remaining.Nanoseconds())
+ if err := copyTimespecOut(t, rem, &timeleft); err != nil {
+ return err
+ }
}
- }
-
- // Did we just block for the entire duration?
- if err == syserror.ETIMEDOUT {
- return nil
- }
- // If interrupted, arrange for a restart with the remaining duration.
- if err == syserror.ErrInterrupted {
+ // Arrange for a restart with the remaining duration.
t.SetSyscallRestartBlock(&clockNanosleepRestartBlock{
c: c,
duration: remaining,
rem: rem,
})
return kernel.ERESTART_RESTARTBLOCK
+ default:
+ panic(fmt.Sprintf("Impossible BlockWithTimer error %v", err))
}
-
- return err
}
// Nanosleep implements linux syscall Nanosleep(2).
diff --git a/pkg/sentry/syscalls/linux/sys_utsname.go b/pkg/sentry/syscalls/linux/sys_utsname.go
index 271ace08e..748e8dd8d 100644
--- a/pkg/sentry/syscalls/linux/sys_utsname.go
+++ b/pkg/sentry/syscalls/linux/sys_utsname.go
@@ -79,11 +79,11 @@ func Sethostname(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.S
return 0, nil, syserror.EINVAL
}
- name, err := t.CopyInString(nameAddr, int(size))
- if err != nil {
+ name := make([]byte, size)
+ if _, err := t.CopyInBytes(nameAddr, name); err != nil {
return 0, nil, err
}
- utsns.SetHostName(name)
+ utsns.SetHostName(string(name))
return 0, nil, nil
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-29 17:16:03 +0000