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authorZach Koopmans <zkoopmans@google.com>2019-12-05 13:22:31 -0800
committergVisor bot <gvisor-bot@google.com>2019-12-05 13:24:05 -0800
commit0a32c0235744191947a6bf890031026e06788837 (patch)
treeb0ef662a9ad6c87e08e5b88948b75c2f537cf731
parent02258607f97353932d56bfde9274d50dda18e374 (diff)
Create correct file for /proc/[pid]/task/[tid]/io
PiperOrigin-RevId: 284038840
-rw-r--r--pkg/sentry/fs/proc/task.go32
-rw-r--r--test/syscalls/linux/proc.cc40
2 files changed, 57 insertions, 15 deletions
diff --git a/pkg/sentry/fs/proc/task.go b/pkg/sentry/fs/proc/task.go
index 2a598149d..0e46c5fb7 100644
--- a/pkg/sentry/fs/proc/task.go
+++ b/pkg/sentry/fs/proc/task.go
@@ -67,29 +67,28 @@ type taskDir struct {
var _ fs.InodeOperations = (*taskDir)(nil)
// newTaskDir creates a new proc task entry.
-func (p *proc) newTaskDir(t *kernel.Task, msrc *fs.MountSource, showSubtasks bool) *fs.Inode {
+func (p *proc) newTaskDir(t *kernel.Task, msrc *fs.MountSource, isThreadGroup bool) *fs.Inode {
contents := map[string]*fs.Inode{
- "auxv": newAuxvec(t, msrc),
- "cmdline": newExecArgInode(t, msrc, cmdlineExecArg),
- "comm": newComm(t, msrc),
- "environ": newExecArgInode(t, msrc, environExecArg),
- "exe": newExe(t, msrc),
- "fd": newFdDir(t, msrc),
- "fdinfo": newFdInfoDir(t, msrc),
- "gid_map": newGIDMap(t, msrc),
- // FIXME(b/123511468): create the correct io file for threads.
- "io": newIO(t, msrc),
+ "auxv": newAuxvec(t, msrc),
+ "cmdline": newExecArgInode(t, msrc, cmdlineExecArg),
+ "comm": newComm(t, msrc),
+ "environ": newExecArgInode(t, msrc, environExecArg),
+ "exe": newExe(t, msrc),
+ "fd": newFdDir(t, msrc),
+ "fdinfo": newFdInfoDir(t, msrc),
+ "gid_map": newGIDMap(t, msrc),
+ "io": newIO(t, msrc, isThreadGroup),
"maps": newMaps(t, msrc),
"mountinfo": seqfile.NewSeqFileInode(t, &mountInfoFile{t: t}, msrc),
"mounts": seqfile.NewSeqFileInode(t, &mountsFile{t: t}, msrc),
"ns": newNamespaceDir(t, msrc),
"smaps": newSmaps(t, msrc),
- "stat": newTaskStat(t, msrc, showSubtasks, p.pidns),
+ "stat": newTaskStat(t, msrc, isThreadGroup, p.pidns),
"statm": newStatm(t, msrc),
"status": newStatus(t, msrc, p.pidns),
"uid_map": newUIDMap(t, msrc),
}
- if showSubtasks {
+ if isThreadGroup {
contents["task"] = p.newSubtasks(t, msrc)
}
if len(p.cgroupControllers) > 0 {
@@ -619,8 +618,11 @@ type ioData struct {
ioUsage
}
-func newIO(t *kernel.Task, msrc *fs.MountSource) *fs.Inode {
- return newProcInode(t, seqfile.NewSeqFile(t, &ioData{t.ThreadGroup()}), msrc, fs.SpecialFile, t)
+func newIO(t *kernel.Task, msrc *fs.MountSource, isThreadGroup bool) *fs.Inode {
+ if isThreadGroup {
+ return newProcInode(t, seqfile.NewSeqFile(t, &ioData{t.ThreadGroup()}), msrc, fs.SpecialFile, t)
+ }
+ return newProcInode(t, seqfile.NewSeqFile(t, &ioData{t}), msrc, fs.SpecialFile, t)
}
// NeedsUpdate returns whether the generation is old or not.
diff --git a/test/syscalls/linux/proc.cc b/test/syscalls/linux/proc.cc
index 512de5ee0..8cf08991b 100644
--- a/test/syscalls/linux/proc.cc
+++ b/test/syscalls/linux/proc.cc
@@ -37,6 +37,7 @@
#include <map>
#include <memory>
#include <ostream>
+#include <regex>
#include <string>
#include <unordered_set>
#include <utility>
@@ -51,6 +52,7 @@
#include "absl/strings/str_split.h"
#include "absl/strings/string_view.h"
#include "absl/synchronization/mutex.h"
+#include "absl/synchronization/notification.h"
#include "absl/time/clock.h"
#include "absl/time/time.h"
#include "test/util/capability_util.h"
@@ -1988,6 +1990,44 @@ TEST(Proc, GetdentsEnoent) {
SyscallFailsWithErrno(ENOENT));
}
+void CheckSyscwFromIOFile(const std::string& path, const std::string& regex) {
+ std::string output;
+ ASSERT_NO_ERRNO(GetContents(path, &output));
+ ASSERT_THAT(output, ContainsRegex(absl::StrCat("syscw:\\s+", regex, "\n")));
+}
+
+// Checks that there is variable accounting of IO between threads/tasks.
+TEST(Proc, PidTidIOAccounting) {
+ absl::Notification notification;
+
+ // Run a thread with a bunch of writes. Check that io account records exactly
+ // the number of write calls. File open/close is there to prevent buffering.
+ ScopedThread writer([&notification] {
+ const int num_writes = 100;
+ for (int i = 0; i < num_writes; i++) {
+ auto path = ASSERT_NO_ERRNO_AND_VALUE(TempPath::CreateFile());
+ ASSERT_NO_ERRNO(SetContents(path.path(), "a"));
+ }
+ notification.Notify();
+ const std::string& writer_dir =
+ absl::StrCat("/proc/", getpid(), "/task/", gettid(), "/io");
+
+ CheckSyscwFromIOFile(writer_dir, std::to_string(num_writes));
+ });
+
+ // Run a thread and do no writes. Check that no writes are recorded.
+ ScopedThread noop([&notification] {
+ notification.WaitForNotification();
+ const std::string& noop_dir =
+ absl::StrCat("/proc/", getpid(), "/task/", gettid(), "/io");
+
+ CheckSyscwFromIOFile(noop_dir, "0");
+ });
+
+ writer.Join();
+ noop.Join();
+}
+
} // namespace
} // namespace testing
} // namespace gvisor