/**
* seccomp_run_filters - evaluates all seccomp filters against @syscall
* @syscall: number of the current system call
*
* Returns valid seccomp BPF response codes.
*/
static u32 seccomp_run_filters(struct seccomp_data *sd)
{
struct seccomp_data sd_local;
u32 ret = SECCOMP_RET_ALLOW;
/* Make sure cross-thread synced filter points somewhere sane. */
struct seccomp_filter *f =
lockless_dereference(current->seccomp.filter);
/* Ensure unexpected behavior doesn't result in failing open. */
if (unlikely(WARN_ON(f == NULL)))
return SECCOMP_RET_KILL;
if (!sd) {
populate_seccomp_data(&sd_local);
sd = &sd_local;
}
/*
* All filters in the list are evaluated and the lowest BPF return
* value always takes priority (ignoring the DATA).
*/
for (; f; f = f->prev) {
u32 cur_ret = BPF_PROG_RUN(f->prog, (void *)sd);
if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION))
ret = cur_ret;
}
return ret;
}
static struct dentry *ovl_upperdentry_dereference(struct ovl_entry *oe)
{
return lockless_dereference(oe->__upperdentry);
}