bpf: Add name to struct bpf_ksym

[mirror_ubuntu-hirsute-kernel.git] / include / linux / filter.h

diff --git a/include/linux/filter.h b/include/linux/filter.h
index f349e2c0884c4cace4337b1ff730ff5002cc942e..9b5aa5c483ccb59be7ea7be2fe856b2995c64344 100644 (file)
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -561,7 +561,7 @@ DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
 
 #define __BPF_PROG_RUN(prog, ctx, dfunc)       ({                      \
        u32 ret;                                                        \
-       cant_sleep();                                                   \
+       cant_migrate();                                                 \
        if (static_branch_unlikely(&bpf_stats_enabled_key)) {           \
                struct bpf_prog_stats *stats;                           \
                u64 start = sched_clock();                              \
@@ -576,8 +576,30 @@ DECLARE_STATIC_KEY_FALSE(bpf_stats_enabled_key);
        }                                                               \
        ret; })
 
-#define BPF_PROG_RUN(prog, ctx) __BPF_PROG_RUN(prog, ctx,              \
-                                              bpf_dispatcher_nopfunc)
+#define BPF_PROG_RUN(prog, ctx)                                                \
+       __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func)
+
+/*
+ * Use in preemptible and therefore migratable context to make sure that
+ * the execution of the BPF program runs on one CPU.
+ *
+ * This uses migrate_disable/enable() explicitly to document that the
+ * invocation of a BPF program does not require reentrancy protection
+ * against a BPF program which is invoked from a preempting task.
+ *
+ * For non RT enabled kernels migrate_disable/enable() maps to
+ * preempt_disable/enable(), i.e. it disables also preemption.
+ */
+static inline u32 bpf_prog_run_pin_on_cpu(const struct bpf_prog *prog,
+                                         const void *ctx)
+{
+       u32 ret;
+
+       migrate_disable();
+       ret = __BPF_PROG_RUN(prog, ctx, bpf_dispatcher_nop_func);
+       migrate_enable();
+       return ret;
+}
 
 #define BPF_SKB_CB_LEN QDISC_CB_PRIV_LEN
 
@@ -655,6 +677,7 @@ static inline u8 *bpf_skb_cb(struct sk_buff *skb)
        return qdisc_skb_cb(skb)->data;
 }
 
+/* Must be invoked with migration disabled */
 static inline u32 __bpf_prog_run_save_cb(const struct bpf_prog *prog,
                                         struct sk_buff *skb)
 {
@@ -680,9 +703,9 @@ static inline u32 bpf_prog_run_save_cb(const struct bpf_prog *prog,
 {
        u32 res;
 
-       preempt_disable();
+       migrate_disable();
        res = __bpf_prog_run_save_cb(prog, skb);
-       preempt_enable();
+       migrate_enable();
        return res;
 }
 
@@ -695,13 +718,11 @@ static inline u32 bpf_prog_run_clear_cb(const struct bpf_prog *prog,
        if (unlikely(prog->cb_access))
                memset(cb_data, 0, BPF_SKB_CB_LEN);
 
-       preempt_disable();
-       res = BPF_PROG_RUN(prog, skb);
-       preempt_enable();
+       res = bpf_prog_run_pin_on_cpu(prog, skb);
        return res;
 }
 
-DECLARE_BPF_DISPATCHER(bpf_dispatcher_xdp)
+DECLARE_BPF_DISPATCHER(xdp)
 
 static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
                                            struct xdp_buff *xdp)
@@ -712,8 +733,7 @@ static __always_inline u32 bpf_prog_run_xdp(const struct bpf_prog *prog,
         * already takes rcu_read_lock() when fetching the program, so
         * it's not necessary here anymore.
         */
-       return __BPF_PROG_RUN(prog, xdp,
-                             BPF_DISPATCHER_FUNC(bpf_dispatcher_xdp));
+       return __BPF_PROG_RUN(prog, xdp, BPF_DISPATCHER_FUNC(xdp));
 }
 
 void bpf_prog_change_xdp(struct bpf_prog *prev_prog, struct bpf_prog *prog);
@@ -1063,7 +1083,6 @@ bpf_address_lookup(unsigned long addr, unsigned long *size,
 
 void bpf_prog_kallsyms_add(struct bpf_prog *fp);
 void bpf_prog_kallsyms_del(struct bpf_prog *fp);
-void bpf_get_prog_name(const struct bpf_prog *prog, char *sym);
 
 #else /* CONFIG_BPF_JIT */
 
@@ -1132,11 +1151,6 @@ static inline void bpf_prog_kallsyms_del(struct bpf_prog *fp)
 {
 }
 
-static inline void bpf_get_prog_name(const struct bpf_prog *prog, char *sym)
-{
-       sym[0] = '\0';
-}
-
 #endif /* CONFIG_BPF_JIT */
 
 void bpf_prog_kallsyms_del_all(struct bpf_prog *fp);