Let's add more of the most basic operations to "@default" as absolute
baseline needed by glibc and such to operate. Specifically:
futex, get_robust_list, get_thread_area, membarrier, set_robust_list,
set_thread_area, set_tid_address are all required to properly implement
mutexes and other thread synchronization logic. Given that a ton of
datastructures are protected by mutexes (such as stdio and such), let's
just whitelist this by default, so that things can just work.
restart_syscall is used to implement EAGAIN SA_RESTART stuff in some
archs, and synthesized by the kernel without any explicit user logic,
hence let's make this work out of the box.
"execve\0"
"exit\0"
"exit_group\0"
+ "futex\0"
+ "get_robust_list\0"
+ "get_thread_area\0"
"getrlimit\0" /* make sure processes can query stack size and such */
"gettimeofday\0"
+ "membarrier\0"
"nanosleep\0"
"pause\0"
+ "restart_syscall\0"
"rt_sigreturn\0"
+ "set_robust_list\0"
+ "set_thread_area\0"
+ "set_tid_address\0"
"sigreturn\0"
"time\0"
},