linux-kernel - [PATCH v7 05/20] spi: mxic: Avoid endianness problems with 2-byte opcodes

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:   Fri, 22 May 2020 15:42:46 +0530
From:   Pratyush Yadav <p.yadav@...com>
To:     Tudor Ambarus <tudor.ambarus@...rochip.com>,
        Miquel Raynal <miquel.raynal@...tlin.com>,
        Richard Weinberger <richard@....at>,
        Vignesh Raghavendra <vigneshr@...com>,
        Mark Brown <broonie@...nel.org>,
        Nicolas Ferre <nicolas.ferre@...rochip.com>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        Ludovic Desroches <ludovic.desroches@...rochip.com>,
        Matthias Brugger <matthias.bgg@...il.com>,
        <linux-mtd@...ts.infradead.org>, <linux-kernel@...r.kernel.org>,
        <linux-spi@...r.kernel.org>,
        <linux-arm-kernel@...ts.infradead.org>,
        <linux-mediatek@...ts.infradead.org>
CC:     Pratyush Yadav <p.yadav@...com>, Sekhar Nori <nsekhar@...com>,
        Boris Brezillon <boris.brezillon@...labora.com>,
        Mason Yang <masonccyang@...c.com.tw>
Subject: [PATCH v7 05/20] spi: mxic: Avoid endianness problems with 2-byte opcodes

spi-mem now supports 2-byte opcodes. Since we directly use the address
of the opcode in data transfer, the result can be different based on
whether the machine is little endian or big endian. So instead extract
the individual bytes from the opcode before using them.

Suggested-by: Boris Brezillon <boris.brezillon@...labora.com>
Signed-off-by: Pratyush Yadav <p.yadav@...com>
---
 drivers/spi/spi-mxic.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-mxic.c b/drivers/spi/spi-mxic.c
index 69491f3a515d..c3f4136a7c1d 100644
--- a/drivers/spi/spi-mxic.c
+++ b/drivers/spi/spi-mxic.c
@@ -356,6 +356,7 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 	int nio = 1, i, ret;
 	u32 ss_ctrl;
 	u8 addr[8];
+	u8 cmd[2];
 
 	ret = mxic_spi_set_freq(mxic, mem->spi->max_speed_hz);
 	if (ret)
@@ -393,7 +394,10 @@ static int mxic_spi_mem_exec_op(struct spi_mem *mem,
 	writel(readl(mxic->regs + HC_CFG) | HC_CFG_MAN_CS_ASSERT,
 	       mxic->regs + HC_CFG);
 
-	ret = mxic_spi_data_xfer(mxic, &op->cmd.opcode, NULL, 1);
+	for (i = 0; i < op->cmd.nbytes; i++)
+		cmd[i] = op->cmd.opcode >> (8 * (op->cmd.nbytes - i - 1));
+
+	ret = mxic_spi_data_xfer(mxic, cmd, NULL, op->cmd.nbytes);
 	if (ret)
 		goto out;
 
-- 
2.26.2