diff options
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/trace/bpf_trace.c | 67 |
1 files changed, 37 insertions, 30 deletions
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 52c2998e1dc3..172ef545730d 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -80,7 +80,8 @@ u64 bpf_get_stack(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5); static int bpf_btf_printf_prepare(struct btf_ptr *ptr, u32 btf_ptr_size, u64 flags, const struct btf **btf, s32 *btf_id); -static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip); +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx); +static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx); /** * trace_call_bpf - invoke BPF program @@ -1042,7 +1043,7 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { BPF_CALL_1(bpf_get_func_ip_kprobe_multi, struct pt_regs *, regs) { - return instruction_pointer(regs); + return bpf_kprobe_multi_entry_ip(current->bpf_ctx); } static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { @@ -1054,7 +1055,7 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe_multi = { BPF_CALL_1(bpf_get_attach_cookie_kprobe_multi, struct pt_regs *, regs) { - return bpf_kprobe_multi_cookie(current->bpf_ctx, instruction_pointer(regs)); + return bpf_kprobe_multi_cookie(current->bpf_ctx); } static const struct bpf_func_proto bpf_get_attach_cookie_proto_kmulti = { @@ -2219,15 +2220,16 @@ struct bpf_kprobe_multi_link { struct bpf_link link; struct fprobe fp; unsigned long *addrs; - /* - * The run_ctx here is used to get struct bpf_kprobe_multi_link in - * get_attach_cookie helper, so it can't be used to store data. - */ - struct bpf_run_ctx run_ctx; u64 *cookies; u32 cnt; }; +struct bpf_kprobe_multi_run_ctx { + struct bpf_run_ctx run_ctx; + struct bpf_kprobe_multi_link *link; + unsigned long entry_ip; +}; + static void bpf_kprobe_multi_link_release(struct bpf_link *link) { struct bpf_kprobe_multi_link *kmulti_link; @@ -2281,18 +2283,21 @@ static int bpf_kprobe_multi_cookie_cmp(const void *a, const void *b, const void return __bpf_kprobe_multi_cookie_cmp(a, b); } -static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip) +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) { + struct bpf_kprobe_multi_run_ctx *run_ctx; struct bpf_kprobe_multi_link *link; + u64 *cookie, entry_ip; unsigned long *addr; - u64 *cookie; if (WARN_ON_ONCE(!ctx)) return 0; - link = container_of(ctx, struct bpf_kprobe_multi_link, run_ctx); + run_ctx = container_of(current->bpf_ctx, struct bpf_kprobe_multi_run_ctx, run_ctx); + link = run_ctx->link; if (!link->cookies) return 0; - addr = bsearch(&ip, link->addrs, link->cnt, sizeof(ip), + entry_ip = run_ctx->entry_ip; + addr = bsearch(&entry_ip, link->addrs, link->cnt, sizeof(entry_ip), __bpf_kprobe_multi_cookie_cmp); if (!addr) return 0; @@ -2300,10 +2305,22 @@ static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip) return *cookie; } +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); + return run_ctx->entry_ip; +} + static int kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, - struct pt_regs *regs) + unsigned long entry_ip, struct pt_regs *regs) { + struct bpf_kprobe_multi_run_ctx run_ctx = { + .link = link, + .entry_ip = entry_ip, + }; struct bpf_run_ctx *old_run_ctx; int err; @@ -2314,7 +2331,7 @@ kprobe_multi_link_prog_run(struct bpf_kprobe_multi_link *link, migrate_disable(); rcu_read_lock(); - old_run_ctx = bpf_set_run_ctx(&link->run_ctx); + old_run_ctx = bpf_set_run_ctx(&run_ctx.run_ctx); err = bpf_prog_run(link->link.prog, regs); bpf_reset_run_ctx(old_run_ctx); rcu_read_unlock(); @@ -2329,24 +2346,10 @@ static void kprobe_multi_link_handler(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs) { - unsigned long saved_ip = instruction_pointer(regs); struct bpf_kprobe_multi_link *link; - /* - * Because fprobe's regs->ip is set to the next instruction of - * dynamic-ftrace instruction, correct entry ip must be set, so - * that the bpf program can access entry address via regs as same - * as kprobes. - * - * Both kprobe and kretprobe see the entry ip of traced function - * as instruction pointer. - */ - instruction_pointer_set(regs, entry_ip); - link = container_of(fp, struct bpf_kprobe_multi_link, fp); - kprobe_multi_link_prog_run(link, regs); - - instruction_pointer_set(regs, saved_ip); + kprobe_multi_link_prog_run(link, entry_ip, regs); } static int @@ -2513,7 +2516,11 @@ int bpf_kprobe_multi_link_attach(const union bpf_attr *attr, struct bpf_prog *pr { return -EOPNOTSUPP; } -static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx, u64 ip) +static u64 bpf_kprobe_multi_cookie(struct bpf_run_ctx *ctx) +{ + return 0; +} +static u64 bpf_kprobe_multi_entry_ip(struct bpf_run_ctx *ctx) { return 0; } |