From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELtT5WCsj74GpTpD4WTVkbq9SXGsTxi8M2OfcgPA0zYr/yXq78TjNDO49WOTAy8gOdtPoi9S ARC-Seal: i=1; a=rsa-sha256; t=1520859051; cv=none; d=google.com; s=arc-20160816; b=wBf/QZXSl9tW8B2XsP1H12p+rDEeo7yrjWG7xFIUqsO3bh1smFg+swKlwtrO10iclV 88+edSY+zvgmCYsz1sf5dE05VDCESP/a/2DzA6R+RnGosQlSpyKOCsKhe5rFRmnq24Ea uqIT7WlxD97nmJAbqDmL/ZEm1c/n3/rVGaFCOE8jcdoHXJUEFIX04FvgIleMhrl6xd1M HuxSUM6r1I6rv6XYImLMsaqMf1U1larYb6SZ+mQOufRmA7nJYYMRRFF3fp+6MZoiIi1s J5USde7Zn5uxJKhoXF1E1ie8rWnIt4kEnpP3zZHKUJU8QtkIf27m0mASYySfKyuOc2wb S0HA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=message-id:date:subject:cc:to:from:dkim-signature:delivered-to :list-id:list-subscribe:list-unsubscribe:list-help:list-post :precedence:mailing-list:arc-authentication-results; bh=MoiqE9ho08LAgmLjc7kM/OARU7Flf5Yw/ajGZERHywo=; b=PlHLaAjw/8bNtr+VCVLV3hImCjVri49V1Mn4/JSPPIoBE3CfIP1frFPfM0rgxPqKDs eV4CO1qyOYaM1Ee1vZCrPCuHObZD8pLPtKM0xxDx5kZC+Ne3O76P3CtJXx534J3Dxul4 23wFSUN0JmuHCA5Gk0T4bQCkdNqS+erb+0lNlyMAk5Ib4wy760BtnG9ylYlIe1HQ5M6C QXHFV9ZgFv2PJx1nA5Y9sS3SpKUuPiiREfxVD8X3AYHbBNozYO2jndDRBHV4s6vhogix zprOdNJxrZLV1ECZ4pg19usEzCeV+FgsINkVKpYXVMGj2mIsJGQgoLYfUjOut+u5EtIJ T6Bw== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Iync2Byw; spf=pass (google.com: domain of kernel-hardening-return-12460-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12460-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=Iync2Byw; spf=pass (google.com: domain of kernel-hardening-return-12460-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12460-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: From: Salvatore Mesoraca To: linux-kernel@vger.kernel.org Cc: kernel-hardening@lists.openwall.com, linux-scsi@vger.kernel.org, "James E.J. Bottomley" , "Martin K. Petersen" , "Tobin C. Harding" , Dario Ballabio , Kees Cook , Salvatore Mesoraca , valdis.kletnieks@vt.edu Subject: [PATCH v2] scsi: eata: drop VLA in reorder() Date: Mon, 12 Mar 2018 13:48:57 +0100 Message-Id: <1520858937-3582-1-git-send-email-s.mesoraca16@gmail.com> X-Mailer: git-send-email 1.9.1 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594676969721761588?= X-GMAIL-MSGID: =?utf-8?q?1594736300936823890?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: Avoid 3 VLAs[1] by using a single dinamically allocated array and some helper variables: we don't need 3 arrays. [1] https://lkml.org/lkml/2018/3/7/621 Signed-off-by: Salvatore Mesoraca --- drivers/scsi/eata.c | 40 ++++++++++++++++++++++++++-------------- 1 file changed, 26 insertions(+), 14 deletions(-) diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c index 6501c33..8ba44b7 100644 --- a/drivers/scsi/eata.c +++ b/drivers/scsi/eata.c @@ -2091,12 +2091,14 @@ static void sort(unsigned long sk[], unsigned int da[], unsigned int n, static int reorder(struct hostdata *ha, unsigned long cursec, unsigned int ihdlr, unsigned int il[], unsigned int n_ready) { + int overlap; struct scsi_cmnd *SCpnt; struct mscp *cpp; unsigned int k, n; unsigned int rev = 0, s = 1, r = 1; - unsigned int input_only = 1, overlap = 0; - unsigned long sl[n_ready], pl[n_ready], ll[n_ready]; + unsigned int input_only = 1; + unsigned long *sl; + unsigned long sl_zero, sl_cur, sl_prev, ll_cur, ll_prev; unsigned long maxsec = 0, minsec = ULONG_MAX, seek = 0, iseek = 0; unsigned long ioseek = 0; @@ -2115,6 +2117,12 @@ static int reorder(struct hostdata *ha, unsigned long cursec, if (n_ready <= 1) return 0; + overlap = -ENOMEM; + sl = kcalloc(n_ready, sizeof(*sl), GFP_ATOMIC); + if (!sl) + goto out; + overlap = 0; + for (n = 0; n < n_ready; n++) { k = il[n]; cpp = &ha->cp[k]; @@ -2164,31 +2172,33 @@ static int reorder(struct hostdata *ha, unsigned long cursec, if (!((rev && r) || (!rev && s))) sort(sl, il, n_ready, rev); + sl_zero = sl[0]; + if (!input_only) for (n = 0; n < n_ready; n++) { k = il[n]; cpp = &ha->cp[k]; SCpnt = cpp->SCpnt; - ll[n] = blk_rq_sectors(SCpnt->request); - pl[n] = SCpnt->serial_number; + ll_cur = blk_rq_sectors(SCpnt->request); + sl_cur = sl[n]; + sl[n] = SCpnt->serial_number; - if (!n) - continue; - - if ((sl[n] == sl[n - 1]) - || (!rev && ((sl[n - 1] + ll[n - 1]) > sl[n])) - || (rev && ((sl[n] + ll[n]) > sl[n - 1]))) + if (n && ((sl_cur == sl_prev) + || (!rev && ((sl_prev + ll_prev) > sl_cur)) + || (rev && ((sl_cur + ll_cur) > sl_prev)))) overlap = 1; + ll_prev = ll_cur; + sl_prev = sl_cur; } if (overlap) - sort(pl, il, n_ready, 0); + sort(sl, il, n_ready, 0); if (link_statistics) { - if (cursec > sl[0]) - iseek = cursec - sl[0]; + if (cursec > sl_zero) + iseek = cursec - sl_zero; else - iseek = sl[0] - cursec; + iseek = sl_zero - cursec; batchcount++; readycount += n_ready; seeknosort += seek / 1024; @@ -2225,6 +2235,8 @@ static int reorder(struct hostdata *ha, unsigned long cursec, YESNO(overlap), cpp->din); } #endif + kfree(sl); +out: return overlap; } -- 1.9.1