diff options
| author | Andrei Vagin <avagin@google.com> | 2020-01-06 15:53:21 -0800 |
|---|---|---|
| committer | gVisor bot <gvisor-bot@google.com> | 2020-01-06 15:54:53 -0800 |
| commit | 17c18241cdeb66e75738c3892730f1a434a4bd60 (patch) | |
| tree | ba647bf74ba238a0e0c73763d3d480d7fefe4745 /pkg/sentry/platform/ptrace/subprocess_arm64.go | |
| parent | 51f3ab85e024fcd74c49d273ce5202a207577d31 (diff) | |
platform/syscall: use syscall + int3 to execute a system call in a stub process
Right now, we need to call ptrace(PTRACE_SYSCALL) and wait() twice to execute
one system call in a stub process. With these changes, we will need to call
ptrace + wait only once.
In addition, this allows to workaround the kernel bug when a stub process
doesn't stop on syscall-exit-stop and starts executing the next system call.
Reported-by: syzbot+37143cafa8dc3b5008ee@syzkaller.appspotmail.com
PiperOrigin-RevId: 288393029
Diffstat (limited to 'pkg/sentry/platform/ptrace/subprocess_arm64.go')
| -rw-r--r-- | pkg/sentry/platform/ptrace/subprocess_arm64.go | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/pkg/sentry/platform/ptrace/subprocess_arm64.go b/pkg/sentry/platform/ptrace/subprocess_arm64.go index 62a686ee7..7b975137f 100644 --- a/pkg/sentry/platform/ptrace/subprocess_arm64.go +++ b/pkg/sentry/platform/ptrace/subprocess_arm64.go @@ -127,6 +127,8 @@ func (t *thread) adjustInitRegsRip() { // Pass the expected PPID to the child via X7 when creating stub process func initChildProcessPPID(initregs *syscall.PtraceRegs, ppid int32) { initregs.Regs[7] = uint64(ppid) + // R9 has to be set to 1 when creating stub process. + initregs.Regs[9] = 1 } // patchSignalInfo patches the signal info to account for hitting the seccomp |