From patchwork Thu May 21 15:22:49 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11563385 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0800B913 for ; Thu, 21 May 2020 15:39:42 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id CA0FC207D8 for ; Thu, 21 May 2020 15:39:41 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="o+3+sQwx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org CA0FC207D8 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 0E7BB8000D; Thu, 21 May 2020 11:39:41 -0400 (EDT) Delivered-To: linux-mm-outgoing@kvack.org Received: by kanga.kvack.org (Postfix, from userid 40) id 0BF5B80008; Thu, 21 May 2020 11:39:41 -0400 (EDT) X-Original-To: int-list-linux-mm@kvack.org X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id F3DE38000D; Thu, 21 May 2020 11:39:40 -0400 (EDT) X-Original-To: linux-mm@kvack.org X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id DD89180008 for ; Thu, 21 May 2020 11:39:40 -0400 (EDT) Received: from smtpin19.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id 9BCBA180AD81A for ; Thu, 21 May 2020 15:39:40 +0000 (UTC) X-FDA: 76841136120.19.music75_546736a81f931 X-Spam-Summary: 2,0,0,4a70081ae1f7e2ff,d41d8cd98f00b204,batv+22346298013f76c24147+6115+infradead.org+hch@bombadil.srs.infradead.org,,RULES_HIT:41:69:355:379:541:800:960:966:988:989:1260:1311:1314:1345:1359:1437:1515:1534:1541:1711:1730:1747:1777:1792:2194:2196:2199:2200:2393:2559:2562:2901:3138:3139:3140:3141:3142:3353:3865:3866:3867:3872:4321:4385:5007:6119:6261:6653:10004:11026:11473:11658:11914:12043:12048:12114:12160:12291:12297:12438:12517:12519:12555:12683:12895:12986:13069:13311:13357:13894:14110:14181:14384:14394:14721:21080:21433:21451:21627:21990:30051:30054:30056,0,RBL:198.137.202.133:@bombadil.srs.infradead.org:.lbl8.mailshell.net-64.201.201.201 62.8.0.100,CacheIP:none,Bayesian:0.5,0.5,0.5,Netcheck:none,DomainCache:0,MSF:not bulk,SPF:fn,MSBL:0,DNSBL:neutral,Custom_rules:0:0:0,LFtime:25,LUA_SUMMARY:none X-HE-Tag: music75_546736a81f931 X-Filterd-Recvd-Size: 3952 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) by imf17.hostedemail.com (Postfix) with ESMTP for ; Thu, 21 May 2020 15:39:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description; bh=V3sFdWlGraEdlC3I/bIfjhE1S8jpT74WDIoCxf3hPhY=; b=o+3+sQwxPcLlavSAzP5Wb5mlV7 4pJUfozGOBi+EIdePhgfn8R7BXuK2VW+obVElYBj27JQHb2XZMxDpZqD4cKu6yd1Wxi3zmUey9w4G cSMuw9ovKiqDPDFdMm4g3jRhW2zBbAiBjNndhVDynW8RLwzBEOxtIhEfjSSbDZtt7iOT+FE8Lp/X1 4zpZKlYtOXAtDNdzckmlEGshqtiEiBMF4FjH5cFnTCrwuLlhqu1mhJVCN+7oH3wmcyjYZDegy6Ic7 B6VUnU34PLKnYbmSvgeCI+h00IT3Tyahd8vT8OxgqcmtSYXZH/bYgX5Ix8xedieOXDC7SKeM/T4f0 k/gEciKw==; Received: from [2001:4bb8:18c:5da7:c70:4a89:bc61:2] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1jbn2m-0004RB-Pa; Thu, 21 May 2020 15:23:37 +0000 From: Christoph Hellwig To: x86@kernel.org, Alexei Starovoitov , Daniel Borkmann , Masami Hiramatsu , Linus Torvalds , Andrew Morton Cc: linux-parisc@vger.kernel.org, linux-um@lists.infradead.org, netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH 11/23] bpf: factor out a bpf_trace_copy_string helper Date: Thu, 21 May 2020 17:22:49 +0200 Message-Id: <20200521152301.2587579-12-hch@lst.de> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200521152301.2587579-1-hch@lst.de> References: <20200521152301.2587579-1-hch@lst.de> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Split out a helper to do the fault free access to the string pointer to get it out of a crazy indentation level. Signed-off-by: Christoph Hellwig Acked-by: Andrii Nakryiko --- kernel/trace/bpf_trace.c | 42 +++++++++++++++++++++++----------------- 1 file changed, 24 insertions(+), 18 deletions(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index f5231ffea85b9..9d4080590f711 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -321,6 +321,28 @@ static const struct bpf_func_proto *bpf_get_probe_write_proto(void) return &bpf_probe_write_user_proto; } +static void bpf_trace_copy_string(char *buf, void *unsafe_ptr, char fmt_ptype, + size_t bufsz) +{ + void __user *user_ptr = (__force void __user *)unsafe_ptr; + + buf[0] = 0; + + switch (fmt_ptype) { + case 's': +#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE + strncpy_from_unsafe(buf, unsafe_ptr, bufsz); + break; +#endif + case 'k': + strncpy_from_kernel_nofault(buf, unsafe_ptr, bufsz); + break; + case 'u': + strncpy_from_user_nofault(buf, user_ptr, bufsz); + break; + } +} + /* * Only limited trace_printk() conversion specifiers allowed: * %d %i %u %x %ld %li %lu %lx %lld %lli %llu %llx %p %pks %pus %s @@ -403,24 +425,8 @@ BPF_CALL_5(bpf_trace_printk, char *, fmt, u32, fmt_size, u64, arg1, break; } - buf[0] = 0; - switch (fmt_ptype) { - case 's': -#ifdef CONFIG_ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE - strncpy_from_unsafe(buf, unsafe_ptr, - sizeof(buf)); - break; -#endif - case 'k': - strncpy_from_kernel_nofault(buf, unsafe_ptr, - sizeof(buf)); - break; - case 'u': - strncpy_from_user_nofault(buf, - (__force void __user *)unsafe_ptr, - sizeof(buf)); - break; - } + bpf_trace_copy_string(buf, unsafe_ptr, fmt_ptype, + sizeof(buf)); goto fmt_next; }