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authorgVisor bot <gvisor-bot@google.com>2020-04-29 21:38:41 +0000
committergVisor bot <gvisor-bot@google.com>2020-04-29 21:38:41 +0000
commit8e234f82ffa1db0fdfa781e007a4dac4add0eef8 (patch)
tree1573600b73298ef2b42bf4ef52a7f38441e10f53 /pkg/sentry
parent5b5f6ea0d7c5566f7c2667845037d8b626f4d536 (diff)
parentef94401955bbcfb5296daa29ab373423cdd289db (diff)
Merge release-20200413.0-24-gef94401 (automated)
Diffstat (limited to 'pkg/sentry')
-rwxr-xr-xpkg/sentry/syscalls/linux/vfs2/read_write.go77
1 files changed, 69 insertions, 8 deletions
diff --git a/pkg/sentry/syscalls/linux/vfs2/read_write.go b/pkg/sentry/syscalls/linux/vfs2/read_write.go
index 6c6998f45..3a7ef24f5 100755
--- a/pkg/sentry/syscalls/linux/vfs2/read_write.go
+++ b/pkg/sentry/syscalls/linux/vfs2/read_write.go
@@ -15,9 +15,13 @@
package vfs2
import (
+ "time"
+
"gvisor.dev/gvisor/pkg/abi/linux"
"gvisor.dev/gvisor/pkg/sentry/arch"
"gvisor.dev/gvisor/pkg/sentry/kernel"
+ ktime "gvisor.dev/gvisor/pkg/sentry/kernel/time"
+ "gvisor.dev/gvisor/pkg/sentry/socket"
slinux "gvisor.dev/gvisor/pkg/sentry/syscalls/linux"
"gvisor.dev/gvisor/pkg/sentry/vfs"
"gvisor.dev/gvisor/pkg/syserror"
@@ -88,7 +92,12 @@ func Readv(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscall
func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opts vfs.ReadOptions) (int64, error) {
n, err := file.Read(t, dst, opts)
- if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ if err != syserror.ErrWouldBlock {
+ return n, err
+ }
+
+ allowBlock, deadline, hasDeadline := blockPolicy(t, file)
+ if !allowBlock {
return n, err
}
@@ -108,7 +117,12 @@ func read(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, opt
if err != syserror.ErrWouldBlock {
break
}
- if err := t.Block(ch); err != nil {
+
+ // Wait for a notification that we should retry.
+ if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil {
+ if err == syserror.ETIMEDOUT {
+ err = syserror.ErrWouldBlock
+ }
break
}
}
@@ -233,7 +247,12 @@ func Preadv2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysca
func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, offset int64, opts vfs.ReadOptions) (int64, error) {
n, err := file.PRead(t, dst, offset, opts)
- if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ if err != syserror.ErrWouldBlock {
+ return n, err
+ }
+
+ allowBlock, deadline, hasDeadline := blockPolicy(t, file)
+ if !allowBlock {
return n, err
}
@@ -253,7 +272,12 @@ func pread(t *kernel.Task, file *vfs.FileDescription, dst usermem.IOSequence, of
if err != syserror.ErrWouldBlock {
break
}
- if err := t.Block(ch); err != nil {
+
+ // Wait for a notification that we should retry.
+ if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil {
+ if err == syserror.ETIMEDOUT {
+ err = syserror.ErrWouldBlock
+ }
break
}
}
@@ -320,7 +344,12 @@ func Writev(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Syscal
func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, opts vfs.WriteOptions) (int64, error) {
n, err := file.Write(t, src, opts)
- if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ if err != syserror.ErrWouldBlock {
+ return n, err
+ }
+
+ allowBlock, deadline, hasDeadline := blockPolicy(t, file)
+ if !allowBlock {
return n, err
}
@@ -340,7 +369,12 @@ func write(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, op
if err != syserror.ErrWouldBlock {
break
}
- if err := t.Block(ch); err != nil {
+
+ // Wait for a notification that we should retry.
+ if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil {
+ if err == syserror.ETIMEDOUT {
+ err = syserror.ErrWouldBlock
+ }
break
}
}
@@ -465,7 +499,12 @@ func Pwritev2(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.Sysc
func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
n, err := file.PWrite(t, src, offset, opts)
- if err != syserror.ErrWouldBlock || file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ if err != syserror.ErrWouldBlock {
+ return n, err
+ }
+
+ allowBlock, deadline, hasDeadline := blockPolicy(t, file)
+ if !allowBlock {
return n, err
}
@@ -485,7 +524,12 @@ func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, o
if err != syserror.ErrWouldBlock {
break
}
- if err := t.Block(ch); err != nil {
+
+ // Wait for a notification that we should retry.
+ if err = t.BlockWithDeadline(ch, hasDeadline, deadline); err != nil {
+ if err == syserror.ETIMEDOUT {
+ err = syserror.ErrWouldBlock
+ }
break
}
}
@@ -494,6 +538,23 @@ func pwrite(t *kernel.Task, file *vfs.FileDescription, src usermem.IOSequence, o
return total, err
}
+func blockPolicy(t *kernel.Task, file *vfs.FileDescription) (allowBlock bool, deadline ktime.Time, hasDeadline bool) {
+ if file.StatusFlags()&linux.O_NONBLOCK != 0 {
+ return false, ktime.Time{}, false
+ }
+ // Sockets support read/write timeouts.
+ if s, ok := file.Impl().(socket.SocketVFS2); ok {
+ dl := s.RecvTimeout()
+ if dl < 0 {
+ return false, ktime.Time{}, false
+ }
+ if dl > 0 {
+ return true, t.Kernel().MonotonicClock().Now().Add(time.Duration(dl) * time.Nanosecond), true
+ }
+ }
+ return true, ktime.Time{}, false
+}
+
// Lseek implements Linux syscall lseek(2).
func Lseek(t *kernel.Task, args arch.SyscallArguments) (uintptr, *kernel.SyscallControl, error) {
fd := args[0].Int()