diff options
Diffstat (limited to 'kernel/trace')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 106 |
1 files changed, 92 insertions, 14 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 0ba722b57af3..f5154c051d2c 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1631,6 +1631,17 @@ bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) } } +static bool is_kprobe_multi(const struct bpf_prog *prog) +{ + return prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI || + prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; +} + +static inline bool is_kprobe_session(const struct bpf_prog *prog) +{ + return prog->expected_attach_type == BPF_TRACE_KPROBE_SESSION; +} + static const struct bpf_func_proto * kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1646,13 +1657,13 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) return &bpf_override_return_proto; #endif case BPF_FUNC_get_func_ip: - if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) + if (is_kprobe_multi(prog)) return &bpf_get_func_ip_proto_kprobe_multi; if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) return &bpf_get_func_ip_proto_uprobe_multi; return &bpf_get_func_ip_proto_kprobe; case BPF_FUNC_get_attach_cookie: - if (prog->expected_attach_type == BPF_TRACE_KPROBE_MULTI) + if (is_kprobe_multi(prog)) return &bpf_get_attach_cookie_proto_kmulti; if (prog->expected_attach_type == BPF_TRACE_UPROBE_MULTI) return &bpf_get_attach_cookie_proto_umulti; @@ -2585,6 +2596,12 @@ static int __init bpf_event_init(void) fs_initcall(bpf_event_init); #endif /* CONFIG_MODULES */ +struct bpf_session_run_ctx { + struct bpf_run_ctx run_ctx; + bool is_return; + void *data; +}; + #ifdef CONFIG_FPROBE struct bpf_kprobe_multi_link { struct bpf_link link; @@ -2598,7 +2615,7 @@ struct bpf_kprobe_multi_link { }; struct bpf_kprobe_multi_run_ctx { - struct bpf_run_ctx run_ctx; + struct bpf_session_run_ctx session_ctx; struct bpf_kprobe_multi_link *link; unsigned long entry_ip; }; @@ -2777,7 +2794,8 @@ static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) if (WARN_ON_ONCE(!ctx)) return 0; - run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); + run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, + session_ctx.run_ctx); link = run_ctx->link; if (!link->cookies) return 0; @@ -2794,15 +2812,21 @@ static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) { struct bpf_kprobe_multi_run_ctx *run_ctx; - run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); + run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, + session_ctx.run_ctx); return run_ctx->entry_ip; } static int kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, - unsigned long entry_ip, struct pt_regs *regs) + unsigned long entry_ip, struct pt_regs *regs, + bool is_return, void *data) { struct bpf_kprobe_multi_run_ctx run_ctx = { + .session_ctx = { + .is_return = is_return, + .data = data, + }, .link = link, .entry_ip = entry_ip, }; @@ -2817,7 +2841,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, migrate_disable(); rcu_read_lock(); - old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); + old_run_ctx = bpf_set_run_ctx(&run_ctx.session_ctx.run_ctx); err = bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); rcu_read_unlock(); @@ -2834,10 +2858,11 @@ kprobe_multi_link_handler(struct fprobe *fp, unsigned long fentry_ip, void *data) { struct bpf_kprobe_multi_link *link; + int err; link = container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); - return 0; + err = kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, false, data); + return is_kprobe_session(link->link.prog) ? err : 0; } static void @@ -2848,7 +2873,7 @@ kprobe_multi_link_exit_handler(struct fprobe *fp, unsigned long fentry_ip, struct bpf_kprobe_multi_link *link; link = container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs); + kprobe_multi_link_prog_run(link, get_entry_ip(fentry_ip), regs, true, data); } static int symbols_cmp_r(const void *a, const void *b, const void *priv) @@ -2981,7 +3006,7 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (sizeof(u64) != sizeof(void *)) return -EOPNOTSUPP; - if (prog->expected_attach_type != BPF_TRACE_KPROBE_MULTI) + if (!is_kprobe_multi(prog)) return -EINVAL; flags = attr->link_create.kprobe_multi.flags; @@ -3062,10 +3087,12 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr if (err) goto error; - if (flags & BPF_F_KPROBE_MULTI_RETURN) - link->fp.exit_handler = kprobe_multi_link_exit_handler; - else + if (!(flags & BPF_F_KPROBE_MULTI_RETURN)) link->fp.entry_handler = kprobe_multi_link_handler; + if ((flags & BPF_F_KPROBE_MULTI_RETURN) || is_kprobe_session(prog)) + link->fp.exit_handler = kprobe_multi_link_exit_handler; + if (is_kprobe_session(prog)) + link->fp.entry_data_size = sizeof(u64); link->addrs = addrs; link->cookies = cookies; @@ -3491,3 +3518,54 @@ static u64 bpf_uprobe_multi_entry_ip(struct bpf_run_ctx *ctx) return 0; } #endif /* CONFIG_UPROBES */ + +#ifdef CONFIG_FPROBE +__bpf_kfunc_start_defs(); + +__bpf_kfunc bool bpf_session_is_return(void) +{ + struct bpf_session_run_ctx *session_ctx; + + session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); + return session_ctx->is_return; +} + +__bpf_kfunc __u64 *bpf_session_cookie(void) +{ + struct bpf_session_run_ctx *session_ctx; + + session_ctx = container_of(current->bpf_ctx, struct bpf_session_run_ctx, run_ctx); + return session_ctx->data; +} + +__bpf_kfunc_end_defs(); + +BTF_KFUNCS_START(kprobe_multi_kfunc_set_ids) +BTF_ID_FLAGS(func, bpf_session_is_return) +BTF_ID_FLAGS(func, bpf_session_cookie) +BTF_KFUNCS_END(kprobe_multi_kfunc_set_ids) + +static int bpf_kprobe_multi_filter(const struct bpf_prog *prog, u32 kfunc_id) +{ + if (!btf_id_set8_contains(&kprobe_multi_kfunc_set_ids, kfunc_id)) + return 0; + + if (!is_kprobe_session(prog)) + return -EACCES; + + return 0; +} + +static const struct btf_kfunc_id_set bpf_kprobe_multi_kfunc_set = { + .owner = THIS_MODULE, + .set = &kprobe_multi_kfunc_set_ids, + .filter = bpf_kprobe_multi_filter, +}; + +static int __init bpf_kprobe_multi_kfuncs_init(void) +{ + return register_btf_kfunc_id_set(BPF_PROG_TYPE_KPROBE, &bpf_kprobe_multi_kfunc_set); +} + +late_initcall(bpf_kprobe_multi_kfuncs_init); +#endif |