Thus far we were silently ignoring this flag.
While writing the syscall test for this change I realized that we were
using the async-signal-unsafe `FileDescriptor.reset()` (It's unsafe because
it eventually calls `getenv()`) and `exit()`
in various `fork()` contexts, so I fixed the affected syscall tests.
PiperOrigin-RevId: 925064507
This change adds RSEQ support for platform/kvm. RSEQ is disabled by default.
To support RSEQ, the KVM platform must provide two key capabilities:
(1) A stable, unique CPU ID.
(2) A way to detect when a thread as been preempted.
This implementation provides the necessary support as follows:
CPU ID:
- platform/kvm now advertises the KVM vCPU ID as the cpu_id
Preemption Detection:
- Compares the last context the CPU ran against the current context being
scheduled.
- Compares the context's rseqCPU and CPU ID retrieved by the platform
To facilitate this, several new methods are introduced to the platform
interface and implemented by platform/kvm:
- HasCpuNumbers()
- NumCPUs()
- DetectsCPUPreemption()
- PreemptCpu()
- PreemptAllCpus()
A new user-facing KVM specific option, use_cpu_numbers, is introduced to
effectively feature guard RSEQ. When use_cpu_numbers is true, vCPU IDs are
exposed to the guest, enabling RSEQ support. Setting it to false reverts to
the previous behavior and effectively disables RSEQ for applications that
rely on it.
PiperOrigin-RevId: 844846226
The new mount namespace was being created with the old user namespace,
not the new one. This led to permission errors when creating new mounts.
PiperOrigin-RevId: 676489580
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
- Use new user namespace for namespace creation checks.
- Ensure userns is never nil since it's used by other namespaces.
PiperOrigin-RevId: 234673175
Change-Id: I4b9d9d1e63ce4e24362089793961a996f7540cd9
