The support of PTRACE_SYSEMU on arm64 was added in the 5.3 kernel,
so we can be sure that the current version is higher that 5.3.
And this change moves vsyscall seccomp rules to the arch specific file,
because vsyscall isn't supported on arm64.
PiperOrigin-RevId: 298696493
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
Based on the guidelines at
https://opensource.google.com/docs/releasing/authors/.
1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./'
2. Manual fixup of "Google Inc" references.
3. Add AUTHORS file. Authors may request to be added to this file.
4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS.
Fixes#209
PiperOrigin-RevId: 245823212
Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
This is a defense-in-depth measure. If the sentry is compromised, this prevents
system call injection to the stubs. There is some complexity with respect to
ptrace and seccomp interactions, so this protection is not really available
for kernel versions < 4.8; this is detected dynamically.
Note that this also solves the vsyscall emulation issue by adding in
appropriate trapping for those system calls. It does mean that a compromised
sentry could theoretically inject these into the stub (ignoring the trap and
resume, thereby allowing execution), but they are harmless.
PiperOrigin-RevId: 216647581
Change-Id: Id06c232cbac1f9489b1803ec97f83097fcba8eb8