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Fri, 27 Nov 2020 13:07:12 +1300 Received: from chrisp-dl.ws.atlnz.lc (chrisp-dl.ws.atlnz.lc [10.33.22.20]) by smtp (Postfix) with ESMTP id 1438513EE9F; Fri, 27 Nov 2020 13:07:10 +1300 (NZDT) Received: by chrisp-dl.ws.atlnz.lc (Postfix, from userid 1030) id C34E32800AA; Fri, 27 Nov 2020 13:07:10 +1300 (NZDT) From: Chris Packham To: david.oberhollenzer@sigma-star.at, miquel.raynal@bootlin.com, richard@nod.at, vigneshr@ti.com Subject: [PATCH v2] libmtd: avoid divide by zero Date: Fri, 27 Nov 2020 13:07:08 +1300 Message-Id: <20201127000708.2894-1-chris.packham@alliedtelesis.co.nz> X-Mailer: git-send-email 2.29.2 MIME-Version: 1.0 x-atlnz-ls: pat X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201126_190722_778513_67C69F9A X-CRM114-Status: GOOD ( 17.52 ) X-Spam-Score: -0.2 (/) X-Spam-Report: SpamAssassin version 3.4.4 on merlin.infradead.org summary: Content analysis details: (-0.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.0 SPF_PASS SPF: sender matches SPF record -0.0 SPF_HELO_PASS SPF: HELO matches SPF record 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain X-BeenThere: linux-mtd@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Chris Packham , linux-mtd@lists.infradead.org Sender: "linux-mtd" Errors-To: linux-mtd-bounces+incoming=patchwork.ozlabs.org@lists.infradead.org The concept of erase blocks doesn't apply to mtd-ram devices. Such devices set MTD_NO_ERASE to indicate this and some report 0 for the erase block size. Avoid a divide by zero when calculating the erase block count for such devices. Signed-off-by: Chris Packham Acked-by: Richard Weinberger --- Changes in v2: - Use MTD_NO_ERASE as suggested by Richard lib/libmtd.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/lib/libmtd.c b/lib/libmtd.c index 9d8d0e8..b581d80 100644 --- a/lib/libmtd.c +++ b/lib/libmtd.c @@ -791,7 +791,10 @@ int mtd_get_dev_info1(libmtd_t desc, int mtd_num, struct mtd_dev_info *mtd) return -1; mtd->writable = !!(ret & MTD_WRITEABLE); - mtd->eb_cnt = mtd->size / mtd->eb_size; + if (ret & MTD_NO_ERASE) + mtd->eb_cnt = 1; + else + mtd->eb_cnt = mtd->size / mtd->eb_size; mtd->type = type_str2int(mtd->type_str); mtd->bb_allowed = !!(mtd->type == MTD_NANDFLASH || mtd->type == MTD_MLCNANDFLASH);