The default policy causes immediate termination of a sandboxee that
calls `bpf`(2).
This does not allow for try-call use of `bpf()` to test for optional
features.
To support such try-call use cases, sandboxes would like to say:
```
sandbox2::PolicyBuilder builder;
builder.BlockSyscallWithErrno(__NR_bpf, EPERM);
```
but this doesn't work because the default policy unconditionally treats
`bpf()` as a sandbox violation.
Remove the bpf violation check from the policy if `bpf()` is explicitly
blocked with an errno.
PiperOrigin-RevId: 345239389
Change-Id: I7fcfd3a938c610c8679edf8e1fa0238b32cc9db4
This allows us to remove some uses of macros.
Related changes:
- Make it clear that we support hosting sandboxed binaries from 64-bit
processes only. CPU architectures are x86-64 and POWER64 (little endian).
- Introduced CPU architecture macros, abstracting away compiler specifics
PiperOrigin-RevId: 330918134
Change-Id: Ife7ad5f14723eec9f68055127b0583b8aecd38dd
