From a949133c4b22a87c79310b2d825f2899028d6088 Mon Sep 17 00:00:00 2001
From: Andrei Vagin <avagin@google.com>
Date: Thu, 23 May 2019 23:20:11 -0700
Subject: gvisor: interrupt the sendfile system call if a task has been
 interrupted

sendfile can be called for a big range and it can require significant
amount of time to process it, so we need to handle task interrupts in
this system call.

PiperOrigin-RevId: 249781023
Change-Id: Ifc2ec505d74c06f5ee76f93b8d30d518ec2d4015
---
 pkg/sentry/fs/file.go               | 6 ++++++
 pkg/sentry/kernel/pipe/node_test.go | 4 ++++
 pkg/sentry/kernel/task_block.go     | 5 +++++
 3 files changed, 15 insertions(+)

(limited to 'pkg/sentry')

diff --git a/pkg/sentry/fs/file.go b/pkg/sentry/fs/file.go
index 8f1baca23..8c1307235 100644
--- a/pkg/sentry/fs/file.go
+++ b/pkg/sentry/fs/file.go
@@ -516,12 +516,18 @@ type lockedReader struct {
 
 // Read implements io.Reader.Read.
 func (r *lockedReader) Read(buf []byte) (int, error) {
+	if r.Ctx.Interrupted() {
+		return 0, syserror.ErrInterrupted
+	}
 	n, err := r.File.FileOperations.Read(r.Ctx, r.File, usermem.BytesIOSequence(buf), r.File.offset)
 	return int(n), err
 }
 
 // ReadAt implements io.Reader.ReadAt.
 func (r *lockedReader) ReadAt(buf []byte, offset int64) (int, error) {
+	if r.Ctx.Interrupted() {
+		return 0, syserror.ErrInterrupted
+	}
 	n, err := r.File.FileOperations.Read(r.Ctx, r.File, usermem.BytesIOSequence(buf), offset)
 	return int(n), err
 }
diff --git a/pkg/sentry/kernel/pipe/node_test.go b/pkg/sentry/kernel/pipe/node_test.go
index 7ddecdad8..31d9b0443 100644
--- a/pkg/sentry/kernel/pipe/node_test.go
+++ b/pkg/sentry/kernel/pipe/node_test.go
@@ -48,6 +48,10 @@ func (s *sleeper) Cancel() {
 	s.ch <- struct{}{}
 }
 
+func (s *sleeper) Interrupted() bool {
+	return len(s.ch) != 0
+}
+
 type openResult struct {
 	*fs.File
 	error
diff --git a/pkg/sentry/kernel/task_block.go b/pkg/sentry/kernel/task_block.go
index 30a7f6b1e..1c76c4d84 100644
--- a/pkg/sentry/kernel/task_block.go
+++ b/pkg/sentry/kernel/task_block.go
@@ -158,6 +158,11 @@ func (t *Task) SleepFinish(success bool) {
 	t.Activate()
 }
 
+// Interrupted implements amutex.Sleeper.Interrupted
+func (t *Task) Interrupted() bool {
+	return len(t.interruptChan) != 0
+}
+
 // UninterruptibleSleepStart implements context.Context.UninterruptibleSleepStart.
 func (t *Task) UninterruptibleSleepStart(deactivate bool) {
 	if deactivate {
-- 
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