diff options
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/filter.h | 8 | ||||
| -rw-r--r-- | include/linux/rcupdate.h | 14 | ||||
| -rw-r--r-- | include/net/xdp_sock.h | 2 |
3 files changed, 18 insertions, 6 deletions
diff --git a/include/linux/filter.h b/include/linux/filter.h index 688856e0b28a..472f97074da0 100644 --- a/include/linux/filter.h +++ b/include/linux/filter.h @@ -763,11 +763,9 @@ DECLARE_BPF_DISPATCHER(xdp) static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog, struct xdp_buff *xdp) { - /* Caller needs to hold rcu_read_lock() (!), otherwise program - * can be released while still running, or map elements could be - * freed early while still having concurrent users. XDP fastpath - * already takes rcu_read_lock() when fetching the program, so - * it's not necessary here anymore. + /* Driver XDP hooks are invoked within a single NAPI poll cycle and thus + * under local_bh_disable(), which provides the needed RCU protection + * for accessing map entries. */ return __BPF_PROG_RUN(prog, xdp, BPF_DISPATCHER_FUNC(xdp)); } diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index 9455476c5ba2..d7895b81264e 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -363,6 +363,20 @@ static inline void rcu_preempt_sleep_check(void) { } #define rcu_check_sparse(p, space) #endif /* #else #ifdef __CHECKER__ */ +/** + * unrcu_pointer - mark a pointer as not being RCU protected + * @p: pointer needing to lose its __rcu property + * + * Converts @p from an __rcu pointer to a __kernel pointer. + * This allows an __rcu pointer to be used with xchg() and friends. + */ +#define unrcu_pointer(p) \ +({ \ + typeof(*p) *_________p1 = (typeof(*p) *__force)(p); \ + rcu_check_sparse(p, __rcu); \ + ((typeof(*p) __force __kernel *)(_________p1)); \ +}) + #define __rcu_access_pointer(p, space) \ ({ \ typeof(*p) *_________p1 = (typeof(*p) *__force)READ_ONCE(p); \ diff --git a/include/net/xdp_sock.h b/include/net/xdp_sock.h index 9c0722c6d7ac..fff069d2ed1b 100644 --- a/include/net/xdp_sock.h +++ b/include/net/xdp_sock.h @@ -37,7 +37,7 @@ struct xdp_umem { struct xsk_map { struct bpf_map map; spinlock_t lock; /* Synchronize map updates */ - struct xdp_sock *xsk_map[]; + struct xdp_sock __rcu *xsk_map[]; }; struct xdp_sock { |