On Sun, Oct 11, 2020 at 5:48 PM YiFei Zhu <zhuyifei1...@gmail.com> wrote: > Currently the kernel does not provide an infrastructure to translate > architecture numbers to a human-readable name. Translating syscall > numbers to syscall names is possible through FTRACE_SYSCALL > infrastructure but it does not provide support for compat syscalls. > > This will create a file for each PID as /proc/pid/seccomp_cache. > The file will be empty when no seccomp filters are loaded, or be > in the format of: > <arch name> <decimal syscall number> <ALLOW | FILTER> > where ALLOW means the cache is guaranteed to allow the syscall, > and filter means the cache will pass the syscall to the BPF filter. > > For the docker default profile on x86_64 it looks like: > x86_64 0 ALLOW > x86_64 1 ALLOW > x86_64 2 ALLOW > x86_64 3 ALLOW > [...] > x86_64 132 ALLOW > x86_64 133 ALLOW > x86_64 134 FILTER > x86_64 135 FILTER > x86_64 136 FILTER > x86_64 137 ALLOW > x86_64 138 ALLOW > x86_64 139 FILTER > x86_64 140 ALLOW > x86_64 141 ALLOW > [...] > > This file is guarded by CONFIG_SECCOMP_CACHE_DEBUG with a default > of N because I think certain users of seccomp might not want the > application to know which syscalls are definitely usable. For > the same reason, it is also guarded by CAP_SYS_ADMIN. > > Suggested-by: Jann Horn <ja...@google.com> > Link: > https://lore.kernel.org/lkml/CAG48ez3Ofqp4crXGksLmZY6=fgrf_twyucg7pbkaetvbbop...@mail.gmail.com/ > Signed-off-by: YiFei Zhu <yifei...@illinois.edu>
Reviewed-by: Jann Horn <ja...@google.com>
