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-rw-r--r--pkg/sentry/strace/BUILD1
-rw-r--r--pkg/sentry/strace/linux64.go4
-rw-r--r--pkg/sentry/strace/poll.go72
-rw-r--r--pkg/sentry/strace/strace.go4
-rw-r--r--pkg/sentry/strace/syscalls.go4
-rw-r--r--pkg/sentry/syscalls/linux/sys_poll.go20
6 files changed, 98 insertions, 7 deletions
diff --git a/pkg/sentry/strace/BUILD b/pkg/sentry/strace/BUILD
index bcd94b42e..eaaa4d118 100644
--- a/pkg/sentry/strace/BUILD
+++ b/pkg/sentry/strace/BUILD
@@ -11,6 +11,7 @@ go_library(
"futex.go",
"linux64.go",
"open.go",
+ "poll.go",
"ptrace.go",
"signal.go",
"socket.go",
diff --git a/pkg/sentry/strace/linux64.go b/pkg/sentry/strace/linux64.go
index 22b76449c..6043b8cb1 100644
--- a/pkg/sentry/strace/linux64.go
+++ b/pkg/sentry/strace/linux64.go
@@ -24,7 +24,7 @@ var linuxAMD64 = SyscallMap{
4: makeSyscallInfo("stat", Path, Stat),
5: makeSyscallInfo("fstat", FD, Stat),
6: makeSyscallInfo("lstat", Path, Stat),
- 7: makeSyscallInfo("poll", Hex, Hex, Hex),
+ 7: makeSyscallInfo("poll", PollFDs, Hex, Hex),
8: makeSyscallInfo("lseek", Hex, Hex, Hex),
9: makeSyscallInfo("mmap", Hex, Hex, Hex, Hex, FD, Hex),
10: makeSyscallInfo("mprotect", Hex, Hex, Hex),
@@ -288,7 +288,7 @@ var linuxAMD64 = SyscallMap{
268: makeSyscallInfo("fchmodat", FD, Path, Mode),
269: makeSyscallInfo("faccessat", FD, Path, Oct, Hex),
270: makeSyscallInfo("pselect6", Hex, Hex, Hex, Hex, Hex, Hex),
- 271: makeSyscallInfo("ppoll", Hex, Hex, Timespec, SigSet, Hex),
+ 271: makeSyscallInfo("ppoll", PollFDs, Hex, Timespec, SigSet, Hex),
272: makeSyscallInfo("unshare", CloneFlags),
273: makeSyscallInfo("set_robust_list", Hex, Hex),
274: makeSyscallInfo("get_robust_list", Hex, Hex, Hex),
diff --git a/pkg/sentry/strace/poll.go b/pkg/sentry/strace/poll.go
new file mode 100644
index 000000000..b6b05423c
--- /dev/null
+++ b/pkg/sentry/strace/poll.go
@@ -0,0 +1,72 @@
+// Copyright 2019 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package strace
+
+import (
+ "fmt"
+ "strings"
+
+ "gvisor.googlesource.com/gvisor/pkg/abi"
+ "gvisor.googlesource.com/gvisor/pkg/abi/linux"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/kernel"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/kernel/kdefs"
+ slinux "gvisor.googlesource.com/gvisor/pkg/sentry/syscalls/linux"
+ "gvisor.googlesource.com/gvisor/pkg/sentry/usermem"
+)
+
+// PollEventSet is the set of poll(2) event flags.
+var PollEventSet = abi.FlagSet{
+ {Flag: linux.POLLIN, Name: "POLLIN"},
+ {Flag: linux.POLLPRI, Name: "POLLPRI"},
+ {Flag: linux.POLLOUT, Name: "POLLOUT"},
+ {Flag: linux.POLLERR, Name: "POLLERR"},
+ {Flag: linux.POLLHUP, Name: "POLLHUP"},
+ {Flag: linux.POLLNVAL, Name: "POLLNVAL"},
+ {Flag: linux.POLLRDNORM, Name: "POLLRDNORM"},
+ {Flag: linux.POLLRDBAND, Name: "POLLRDBAND"},
+ {Flag: linux.POLLWRNORM, Name: "POLLWRNORM"},
+ {Flag: linux.POLLWRBAND, Name: "POLLWRBAND"},
+ {Flag: linux.POLLMSG, Name: "POLLMSG"},
+ {Flag: linux.POLLREMOVE, Name: "POLLREMOVE"},
+ {Flag: linux.POLLRDHUP, Name: "POLLRDHUP"},
+ {Flag: linux.POLLFREE, Name: "POLLFREE"},
+ {Flag: linux.POLL_BUSY_LOOP, Name: "POLL_BUSY_LOOP"},
+}
+
+func pollFD(t *kernel.Task, pfd *linux.PollFD, post bool) string {
+ revents := "..."
+ if post {
+ revents = PollEventSet.Parse(uint64(pfd.REvents))
+ }
+ return fmt.Sprintf("{FD: %s, Events: %s, REvents: %s}", fd(t, kdefs.FD(pfd.FD)), PollEventSet.Parse(uint64(pfd.Events)), revents)
+}
+
+func pollFDs(t *kernel.Task, addr usermem.Addr, nfds uint, post bool) string {
+ if addr == 0 {
+ return "null"
+ }
+
+ pfds, err := slinux.CopyInPollFDs(t, addr, nfds)
+ if err != nil {
+ return fmt.Sprintf("%#x (error decoding pollfds: %s)", addr, err)
+ }
+
+ s := make([]string, 0, len(pfds))
+ for i := range pfds {
+ s = append(s, pollFD(t, &pfds[i], post))
+ }
+
+ return fmt.Sprintf("%#x [%s]", addr, strings.Join(s, ", "))
+}
diff --git a/pkg/sentry/strace/strace.go b/pkg/sentry/strace/strace.go
index 398035b65..a6d870b44 100644
--- a/pkg/sentry/strace/strace.go
+++ b/pkg/sentry/strace/strace.go
@@ -438,6 +438,8 @@ func (i *SyscallInfo) pre(t *kernel.Task, args arch.SyscallArguments, maximumBlo
output = append(output, capHeader(t, args[arg].Pointer()))
case CapData:
output = append(output, capData(t, args[arg-1].Pointer(), args[arg].Pointer()))
+ case PollFDs:
+ output = append(output, pollFDs(t, args[arg].Pointer(), uint(args[arg+1].Uint()), false))
case Oct:
output = append(output, "0o"+strconv.FormatUint(args[arg].Uint64(), 8))
case Hex:
@@ -502,6 +504,8 @@ func (i *SyscallInfo) post(t *kernel.Task, args arch.SyscallArguments, rval uint
output[arg] = sigAction(t, args[arg].Pointer())
case PostCapData:
output[arg] = capData(t, args[arg-1].Pointer(), args[arg].Pointer())
+ case PollFDs:
+ output[arg] = pollFDs(t, args[arg].Pointer(), uint(args[arg+1].Uint()), true)
}
}
}
diff --git a/pkg/sentry/strace/syscalls.go b/pkg/sentry/strace/syscalls.go
index 1f255c717..8c897fcbe 100644
--- a/pkg/sentry/strace/syscalls.go
+++ b/pkg/sentry/strace/syscalls.go
@@ -202,6 +202,10 @@ const (
// PostCapData is the data argument to capget(2)/capset(2), formatted
// after syscall execution. The previous argument must be CapHeader.
PostCapData
+
+ // PollFDs is an array of struct pollfd. The number of entries in the
+ // array is in the next argument.
+ PollFDs
)
// defaultFormat is the syscall argument format to use if the actual format is
diff --git a/pkg/sentry/syscalls/linux/sys_poll.go b/pkg/sentry/syscalls/linux/sys_poll.go
index 23fcb907f..17b6768e5 100644
--- a/pkg/sentry/syscalls/linux/sys_poll.go
+++ b/pkg/sentry/syscalls/linux/sys_poll.go
@@ -155,18 +155,28 @@ func pollBlock(t *kernel.Task, pfd []linux.PollFD, timeout time.Duration) (time.
return timeout, n, nil
}
-func doPoll(t *kernel.Task, pfdAddr usermem.Addr, nfds uint, timeout time.Duration) (time.Duration, uintptr, error) {
+// CopyInPollFDs copies an array of struct pollfd unless nfds exceeds the max.
+func CopyInPollFDs(t *kernel.Task, addr usermem.Addr, nfds uint) ([]linux.PollFD, error) {
if uint64(nfds) > t.ThreadGroup().Limits().GetCapped(limits.NumberOfFiles, fileCap) {
- return timeout, 0, syserror.EINVAL
+ return nil, syserror.EINVAL
}
pfd := make([]linux.PollFD, nfds)
if nfds > 0 {
- if _, err := t.CopyIn(pfdAddr, &pfd); err != nil {
- return timeout, 0, err
+ if _, err := t.CopyIn(addr, &pfd); err != nil {
+ return nil, err
}
}
+ return pfd, nil
+}
+
+func doPoll(t *kernel.Task, addr usermem.Addr, nfds uint, timeout time.Duration) (time.Duration, uintptr, error) {
+ pfd, err := CopyInPollFDs(t, addr, nfds)
+ if err != nil {
+ return timeout, 0, err
+ }
+
// Compatibility warning: Linux adds POLLHUP and POLLERR just before
// polling, in fs/select.c:do_pollfd(). Since pfd is copied out after
// polling, changing event masks here is an application-visible difference.
@@ -180,7 +190,7 @@ func doPoll(t *kernel.Task, pfdAddr usermem.Addr, nfds uint, timeout time.Durati
// The poll entries are copied out regardless of whether
// any are set or not. This aligns with the Linux behavior.
if nfds > 0 && err == nil {
- if _, err := t.CopyOut(pfdAddr, pfd); err != nil {
+ if _, err := t.CopyOut(addr, pfd); err != nil {
return remainingTimeout, 0, err
}
}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-02 14:34:10 +0000