From patchwork Tue Jun 29 19:29:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jiri Olsa X-Patchwork-Id: 12350687 X-Patchwork-Delegate: bpf@iogearbox.net Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6D4E4C11F67 for ; Tue, 29 Jun 2021 19:30:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 46A8761DE7 for ; Tue, 29 Jun 2021 19:30:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234665AbhF2Tca (ORCPT ); Tue, 29 Jun 2021 15:32:30 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:22628 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234180AbhF2Tc0 (ORCPT ); Tue, 29 Jun 2021 15:32:26 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1624994999; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=OGsWiBOuAVqf4btUf4cftMKBn0bF9gV/Gnv0HJUJGi8=; b=YhRBXOlD6t/wuk7Wmw1HQoFY8LSiRS5bHo3KqG9yrijDsNYRdqICmMHkS+yf5i58tbMj3p BV0PEBWxyqc+F0H6gWad662ZgyHIEIuy6IOlK4pkOuliTWgAfAT/opXXuE91kKWy+HIoZA Ho3aIfMxCKZWGp1DHsu5OTjmPVOQH5w= Received: from mail-ed1-f69.google.com (mail-ed1-f69.google.com [209.85.208.69]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-544-RHnEGyE2PFiYYEluz2N_aw-1; Tue, 29 Jun 2021 15:29:57 -0400 X-MC-Unique: RHnEGyE2PFiYYEluz2N_aw-1 Received: by mail-ed1-f69.google.com with SMTP id w15-20020a05640234cfb02903951279f8f3so6829129edc.11 for ; Tue, 29 Jun 2021 12:29:57 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=OGsWiBOuAVqf4btUf4cftMKBn0bF9gV/Gnv0HJUJGi8=; b=CZHhZ3KFO539381jSvGp4I7VungCixqvgSYNVef2PGGNGIRwyTioKUSB5Vogd669yL guyQxFizJ/1/A9nAGTYOzazCqEZgQ6o4ho/4qNGBgYXZ2pR0oPDASZvmVXLAKRqIM0X0 eYX9bOcDMcwyMaWrV2Q5SIqDOfqn7apK6dqfhT/NhsfYpNi21E5Wv2llWcC3lumMyqfq n9V6mOpzNjFitW/I7DY3kSQ70DfAsDB+E/5rcg/z4MvX9jjNHrVUF8z+0rKTBXL0rQo9 FV6xUwwf8alus6NI5/K+DpLG/Sr6fOffAKa2pHkyZd5xyKnaK9BbQ2gjR+8wKFiPFaUL b35Q== X-Gm-Message-State: AOAM530URXlcxX+THHTtOYbsoUJEShlOY1tjl1yb7Gpfkv/UauyjQHJM A+jKmHoz5FhmAWpzBIFtgDLl9o9nZqtp/Cm5xAmZbAN79bY0EwB7m/bPy28GZrdKxJKlfQIEWpc v/udJx5bq5wvh X-Received: by 2002:a17:906:4d99:: with SMTP id s25mr28229218eju.349.1624994996596; Tue, 29 Jun 2021 12:29:56 -0700 (PDT) X-Google-Smtp-Source: ABdhPJzWtTBoRXPMKCr1KyV2AoM6ZTq/GwiLioCcV0nux5msmh3rBiUzFuwNQgLyVEVrtLD951GCgg== X-Received: by 2002:a17:906:4d99:: with SMTP id s25mr28229209eju.349.1624994996411; Tue, 29 Jun 2021 12:29:56 -0700 (PDT) Received: from krava.redhat.com ([185.153.78.55]) by smtp.gmail.com with ESMTPSA id n22sm472559eje.3.2021.06.29.12.29.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Jun 2021 12:29:56 -0700 (PDT) From: Jiri Olsa X-Google-Original-From: Jiri Olsa To: Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, Martin KaFai Lau , Song Liu , Yonghong Song , John Fastabend , KP Singh , Masami Hiramatsu Subject: [PATCH bpf-next 4/5] bpf: Add bpf_get_func_ip helper for kprobe programs Date: Tue, 29 Jun 2021 21:29:44 +0200 Message-Id: <20210629192945.1071862-5-jolsa@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210629192945.1071862-1-jolsa@kernel.org> References: <20210629192945.1071862-1-jolsa@kernel.org> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org X-Patchwork-Delegate: bpf@iogearbox.net Adding bpf_get_func_ip helper for BPF_PROG_TYPE_KPROBE programs, so it's now possible to call bpf_get_func_ip from both kprobe and kretprobe programs. Taking the caller's address from 'struct kprobe::addr', which is defined for both kprobe and kretprobe. Signed-off-by: Jiri Olsa --- include/uapi/linux/bpf.h | 2 +- kernel/bpf/verifier.c | 2 ++ kernel/trace/bpf_trace.c | 14 ++++++++++++++ kernel/trace/trace_kprobe.c | 20 ++++++++++++++++++-- kernel/trace/trace_probe.h | 5 +++++ tools/include/uapi/linux/bpf.h | 2 +- 6 files changed, 41 insertions(+), 4 deletions(-) diff --git a/include/uapi/linux/bpf.h b/include/uapi/linux/bpf.h index 83e87ffdbb6e..4894f99a1993 100644 --- a/include/uapi/linux/bpf.h +++ b/include/uapi/linux/bpf.h @@ -4783,7 +4783,7 @@ union bpf_attr { * * u64 bpf_get_func_ip(void *ctx) * Description - * Get address of the traced function (for tracing programs). + * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. */ diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 701ff7384fa7..b66e0a7104f8 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -5979,6 +5979,8 @@ static bool has_get_func_ip(struct bpf_verifier_env *env) return -ENOTSUPP; } return 0; + } else if (type == BPF_PROG_TYPE_KPROBE) { + return 0; } verbose(env, "func %s#%d not supported for program type %d\n", diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index 9edd3b1a00ad..1a5bddce9abd 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -961,6 +961,18 @@ static const struct bpf_func_proto bpf_get_func_ip_proto_tracing = { .arg1_type = ARG_PTR_TO_CTX, }; +BPF_CALL_1(bpf_get_func_ip_kprobe, struct pt_regs *, regs) +{ + return trace_current_kprobe_addr(); +} + +static const struct bpf_func_proto bpf_get_func_ip_proto_kprobe = { + .func = bpf_get_func_ip_kprobe, + .gpl_only = true, + .ret_type = RET_INTEGER, + .arg1_type = ARG_PTR_TO_CTX, +}; + const struct bpf_func_proto * bpf_tracing_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) { @@ -1092,6 +1104,8 @@ kprobe_prog_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog) case BPF_FUNC_override_return: return &bpf_override_return_proto; #endif + case BPF_FUNC_get_func_ip: + return &bpf_get_func_ip_proto_kprobe; default: return bpf_tracing_func_proto(func_id, prog); } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index ea6178cb5e33..b07d5888db14 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1570,6 +1570,18 @@ static int kretprobe_event_define_fields(struct trace_event_call *event_call) } #ifdef CONFIG_PERF_EVENTS +/* Used by bpf get_func_ip helper */ +DEFINE_PER_CPU(u64, current_kprobe_addr) = 0; + +u64 trace_current_kprobe_addr(void) +{ + return *this_cpu_ptr(¤t_kprobe_addr); +} + +static void trace_current_kprobe_set(struct trace_kprobe *tk) +{ + __this_cpu_write(current_kprobe_addr, (u64) tk->rp.kp.addr); +} /* Kprobe profile handler */ static int @@ -1585,6 +1597,7 @@ kprobe_perf_func(struct trace_kprobe *tk, struct pt_regs *regs) unsigned long orig_ip = instruction_pointer(regs); int ret; + trace_current_kprobe_set(tk); ret = trace_call_bpf(call, regs); /* @@ -1631,8 +1644,11 @@ kretprobe_perf_func(struct trace_kprobe *tk, struct kretprobe_instance *ri, int size, __size, dsize; int rctx; - if (bpf_prog_array_valid(call) && !trace_call_bpf(call, regs)) - return; + if (bpf_prog_array_valid(call)) { + trace_current_kprobe_set(tk); + if (!trace_call_bpf(call, regs)) + return; + } head = this_cpu_ptr(call->perf_events); if (hlist_empty(head)) diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 227d518e5ba5..19c979834916 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -199,6 +199,7 @@ DECLARE_BASIC_PRINT_TYPE_FUNC(symbol); #ifdef CONFIG_KPROBE_EVENTS bool trace_kprobe_on_func_entry(struct trace_event_call *call); bool trace_kprobe_error_injectable(struct trace_event_call *call); +u64 trace_current_kprobe_addr(void); #else static inline bool trace_kprobe_on_func_entry(struct trace_event_call *call) { @@ -209,6 +210,10 @@ static inline bool trace_kprobe_error_injectable(struct trace_event_call *call) { return false; } +static inline u64 trace_current_kprobe_addr(void) +{ + return 0; +} #endif /* CONFIG_KPROBE_EVENTS */ struct probe_arg { diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h index 83e87ffdbb6e..4894f99a1993 100644 --- a/tools/include/uapi/linux/bpf.h +++ b/tools/include/uapi/linux/bpf.h @@ -4783,7 +4783,7 @@ union bpf_attr { * * u64 bpf_get_func_ip(void *ctx) * Description - * Get address of the traced function (for tracing programs). + * Get address of the traced function (for tracing and kprobe programs). * Return * Address of the traced function. */