From patchwork Mon Aug 7 13:03:05 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joel Fernandes X-Patchwork-Id: 798625 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=google.com header.i=@google.com header.b="UeLJUuE0"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3xQyRG20Ryz9sR9 for ; Mon, 7 Aug 2017 23:04:26 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751662AbdHGND5 (ORCPT ); Mon, 7 Aug 2017 09:03:57 -0400 Received: from mail-pg0-f46.google.com ([74.125.83.46]:37712 "EHLO mail-pg0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751508AbdHGND3 (ORCPT ); Mon, 7 Aug 2017 09:03:29 -0400 Received: by mail-pg0-f46.google.com with SMTP id y129so1435257pgy.4 for ; Mon, 07 Aug 2017 06:03:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=Rgj/wCj6KPEWi7Mh+r3qBPEtlfoWSkP4PfG5Xb/0h7s=; b=UeLJUuE0z2l6QpgwuChCngfEk/gcg5oXLs9bEZLEVIGuqtDUQgibly4yhM8lO90Xve toMHOt9xqFF2vGI3IksAXSJlzkoBXZHzWqUWRLQngE9YmHtkT4wdgMgjJfpjn8CfWxYE h736vEksUznYXusm5I1eO40aDxLN/7NQCGFVPsLL2qcggvZX/wDitnJjI1ZGTB1mhpJi xHk8ibP6nGos/SYDKt+llBpyFsXXywDBFrCs8F6DjiAar7Q5bVFmPPuVfsiDK0b1RsBl ik1i44Rdd3HcLVpSJmepm/CXWQ5f4Rk5/1+QY24i25DeM5LioMMjD2wK2EwDphaeuU2N GUgg== 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; bh=Rgj/wCj6KPEWi7Mh+r3qBPEtlfoWSkP4PfG5Xb/0h7s=; b=SLy8V77+NjZzn6wY1lDIEhWwY8g1X7UBVzS/IbThcm7EyZKNjYCkLfkJ3yB9ONs5sr PGp0Q7GYqWRjuylIJlEfXlfCHeWxNj8eyJB2mgSS7BATQG9vzRetgjxQNk/ZNe/6ZQNi WuPs4s6NDYi33ydNYhGHZwIw5ijiUP3cw2d5Oa1h9eLUa5lTlGhyEkB3vNYkZ8xAHHAI /5HrcwrfzOgastNdLLdKT2v5PKqEPD3KaMS8YpTWJI/UT3rE56pgr4zTOWai1zJrfrZL JD1P2tAcHJ+Ya+g5xSls7koeMXXTZbONy8YEjWBJT5zukLQTJqmn0pdMGH7J0pW69JY+ Kg8Q== X-Gm-Message-State: AHYfb5h3RF5+07CQU4HEF7xK8NkJLdC6fEXgUypUsTIYwjwuHNZL0lEG Pof85rEgAZ7piBi/ X-Received: by 10.84.231.199 with SMTP id g7mr552189pln.258.1502111008629; Mon, 07 Aug 2017 06:03:28 -0700 (PDT) Received: from joelaf-glaptop0.roam.corp.google.com (c-24-130-92-142.hsd1.ca.comcast.net. [24.130.92.142]) by smtp.gmail.com with ESMTPSA id d28sm2955686pfb.139.2017.08.07.06.03.27 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Mon, 07 Aug 2017 06:03:27 -0700 (PDT) From: Joel Fernandes To: linux-kernel@vger.kernel.org Cc: Chenbo Feng , Alison Chaiken , Juri Lelli , Joel Fernandes , Alexei Starovoitov , Daniel Borkmann , netdev@vger.kernel.org (open list:BPF (Safe dynamic programs and tools)) Subject: [PATCH RFC 4/5] samples/bpf: Fix pt_regs issues when cross-compiling Date: Mon, 7 Aug 2017 06:03:05 -0700 Message-Id: <20170807130306.31530-5-joelaf@google.com> X-Mailer: git-send-email 2.14.0.rc1.383.gd1ce394fe2-goog In-Reply-To: <20170807130306.31530-1-joelaf@google.com> References: <20170807130306.31530-1-joelaf@google.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org BPF samples fail to build when cross-compiling for ARM64 because of incorrect pt_regs param selection. This is because clang defines __x86_64__ and bpf_headers thinks we're building for x86. Since clang is building for the BPF target, it shouldn't make assumptions about what target the BPF program is going to run on. To fix this, lets pass ARCH so the header knows which target the BPF program is being compiled for and can use the correct pt_regs code. Signed-off-by: Joel Fernandes --- samples/bpf/Makefile | 2 +- samples/bpf/bpf_helpers.h | 49 +++++++++++++++++++++++++++++++++++++++++------ 2 files changed, 44 insertions(+), 7 deletions(-) diff --git a/samples/bpf/Makefile b/samples/bpf/Makefile index 7591cdd7fe69..8cbcaffe4001 100644 --- a/samples/bpf/Makefile +++ b/samples/bpf/Makefile @@ -199,7 +199,7 @@ ASM_STUBS := ${ARCH_ASM_STUBS} -include $(src)/generic_asmstubs.h CLANG_ARGS = $(NOSTDINC_FLAGS) $(LINUXINCLUDE) $(EXTRA_CFLAGS) \ -D__KERNEL__ -Wno-unused-value -Wno-pointer-sign \ - $(ASM_STUBS) \ + -D__TARGET_ARCH_$(ARCH) $(ASM_STUBS) \ -Wno-compare-distinct-pointer-types \ -Wno-gnu-variable-sized-type-not-at-end \ -Wno-address-of-packed-member -Wno-tautological-compare \ diff --git a/samples/bpf/bpf_helpers.h b/samples/bpf/bpf_helpers.h index 67c9c4438e4b..199d2e32703a 100644 --- a/samples/bpf/bpf_helpers.h +++ b/samples/bpf/bpf_helpers.h @@ -96,7 +96,42 @@ static int (*bpf_skb_under_cgroup)(void *ctx, void *map, int index) = static int (*bpf_skb_change_head)(void *, int len, int flags) = (void *) BPF_FUNC_skb_change_head; +/* Scan the ARCH passed in from ARCH env variable (see Makefile) */ +#if defined(__TARGET_ARCH_x86) + #define bpf_target_x86 + #define bpf_target_defined +#elif defined(__TARGET_ARCH_s930x) + #define bpf_target_s930x + #define bpf_target_defined +#elif defined(__TARGET_ARCH_arm64) + #define bpf_target_arm64 + #define bpf_target_defined +#elif defined(__TARGET_ARCH_powerpc) + #define bpf_target_powerpc + #define bpf_target_defined +#elif defined(__TARGET_ARCH_sparc) + #define bpf_target_sparc + #define bpf_target_defined +#else + #undef bpf_target_defined +#endif + +/* Fall back to what the compiler says */ +#ifndef bpf_target_defined #if defined(__x86_64__) + #define bpf_target_x86 +#elif defined(__s390x__) + #define bpf_target_s930x +#elif defined(__aarch64__) + #define bpf_target_arm64 +#elif defined(__powerpc__) + #define bpf_target_powerpc +#elif defined(__sparc__) + #define bpf_target_sparc +#endif +#endif + +#if defined(bpf_target_x86) #define PT_REGS_PARM1(x) ((x)->di) #define PT_REGS_PARM2(x) ((x)->si) @@ -109,7 +144,7 @@ static int (*bpf_skb_change_head)(void *, int len, int flags) = #define PT_REGS_SP(x) ((x)->sp) #define PT_REGS_IP(x) ((x)->ip) -#elif defined(__s390x__) +#elif defined(bpf_target_s390x) #define PT_REGS_PARM1(x) ((x)->gprs[2]) #define PT_REGS_PARM2(x) ((x)->gprs[3]) @@ -122,7 +157,7 @@ static int (*bpf_skb_change_head)(void *, int len, int flags) = #define PT_REGS_SP(x) ((x)->gprs[15]) #define PT_REGS_IP(x) ((x)->psw.addr) -#elif defined(__aarch64__) +#elif defined(bpf_target_arm64) #define PT_REGS_PARM1(x) ((x)->regs[0]) #define PT_REGS_PARM2(x) ((x)->regs[1]) @@ -135,7 +170,7 @@ static int (*bpf_skb_change_head)(void *, int len, int flags) = #define PT_REGS_SP(x) ((x)->sp) #define PT_REGS_IP(x) ((x)->pc) -#elif defined(__powerpc__) +#elif defined(bpf_target_powerpc) #define PT_REGS_PARM1(x) ((x)->gpr[3]) #define PT_REGS_PARM2(x) ((x)->gpr[4]) @@ -146,7 +181,7 @@ static int (*bpf_skb_change_head)(void *, int len, int flags) = #define PT_REGS_SP(x) ((x)->sp) #define PT_REGS_IP(x) ((x)->nip) -#elif defined(__sparc__) +#elif defined(bpf_target_sparc) #define PT_REGS_PARM1(x) ((x)->u_regs[UREG_I0]) #define PT_REGS_PARM2(x) ((x)->u_regs[UREG_I1]) @@ -156,6 +191,8 @@ static int (*bpf_skb_change_head)(void *, int len, int flags) = #define PT_REGS_RET(x) ((x)->u_regs[UREG_I7]) #define PT_REGS_RC(x) ((x)->u_regs[UREG_I0]) #define PT_REGS_SP(x) ((x)->u_regs[UREG_FP]) + +/* Should this also be a bpf_target check for the sparc case? */ #if defined(__arch64__) #define PT_REGS_IP(x) ((x)->tpc) #else @@ -164,10 +201,10 @@ static int (*bpf_skb_change_head)(void *, int len, int flags) = #endif -#ifdef __powerpc__ +#ifdef bpf_target_powerpc #define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ (ip) = (ctx)->link; }) #define BPF_KRETPROBE_READ_RET_IP BPF_KPROBE_READ_RET_IP -#elif defined(__sparc__) +#elif bpf_target_sparc #define BPF_KPROBE_READ_RET_IP(ip, ctx) ({ (ip) = PT_REGS_RET(ctx); }) #define BPF_KRETPROBE_READ_RET_IP BPF_KPROBE_READ_RET_IP #else