Signed-off-by: Kir Kolyshkin <[email protected]>

Signed-off-by: lifubang <[email protected]>
Signed-off-by: Kir Kolyshkin <[email protected]>

All the prctl calls that we make (or can potentially make) are limited
to 3 arguments, so it's sufficient to use Syscall (rather than
Syscall6).

This is mostly a cosmetic change.

Signed-off-by: Kir Kolyshkin <[email protected]>

RawSyscall is preferable for syscalls that do not block, and neither
of the ones used by this package do.

This makes the whole thing a bit faster.

Signed-off-by: Kir Kolyshkin <[email protected]>

We need to lock OS thread as this library deals with per-thread
capabilities.

Signed-off-by: Kir Kolyshkin <[email protected]>

The API is the same as in kernel.org/pub/linux/libs/security/libcap/cap
package, although the implementation is a bit simpler (here we only set
capabilities for the calling thread).

Co-authored-by: lifubang <[email protected]>
Signed-off-by: Kir Kolyshkin <[email protected]>

Signed-off-by: Kir Kolyshkin <[email protected]>