diff options
Diffstat (limited to 'drivers/mtd/spi-nor')
-rw-r--r-- | drivers/mtd/spi-nor/Makefile | 1 | ||||
-rw-r--r-- | drivers/mtd/spi-nor/spi-nor.c | 45 |
2 files changed, 43 insertions, 3 deletions
diff --git a/drivers/mtd/spi-nor/Makefile b/drivers/mtd/spi-nor/Makefile index 7d84c5108e17..f4c61d282abd 100644 --- a/drivers/mtd/spi-nor/Makefile +++ b/drivers/mtd/spi-nor/Makefile @@ -1,3 +1,4 @@ +# SPDX-License-Identifier: GPL-2.0 obj-$(CONFIG_MTD_SPI_NOR) += spi-nor.o obj-$(CONFIG_SPI_ASPEED_SMC) += aspeed-smc.o obj-$(CONFIG_SPI_ATMEL_QUADSPI) += atmel-quadspi.o diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c index cf1d4a15e10a..19c000722cbc 100644 --- a/drivers/mtd/spi-nor/spi-nor.c +++ b/drivers/mtd/spi-nor/spi-nor.c @@ -1784,7 +1784,7 @@ spi_nor_set_pp_settings(struct spi_nor_pp_command *pp, * @nor: pointer to a 'struct spi_nor' * @addr: offset in the SFDP area to start reading data from * @len: number of bytes to read - * @buf: buffer where the SFDP data are copied into + * @buf: buffer where the SFDP data are copied into (dma-safe memory) * * Whatever the actual numbers of bytes for address and dummy cycles are * for (Fast) Read commands, the Read SFDP (5Ah) instruction is always @@ -1829,6 +1829,36 @@ read_err: return ret; } +/** + * spi_nor_read_sfdp_dma_unsafe() - read Serial Flash Discoverable Parameters. + * @nor: pointer to a 'struct spi_nor' + * @addr: offset in the SFDP area to start reading data from + * @len: number of bytes to read + * @buf: buffer where the SFDP data are copied into + * + * Wrap spi_nor_read_sfdp() using a kmalloc'ed bounce buffer as @buf is now not + * guaranteed to be dma-safe. + * + * Return: -ENOMEM if kmalloc() fails, the return code of spi_nor_read_sfdp() + * otherwise. + */ +static int spi_nor_read_sfdp_dma_unsafe(struct spi_nor *nor, u32 addr, + size_t len, void *buf) +{ + void *dma_safe_buf; + int ret; + + dma_safe_buf = kmalloc(len, GFP_KERNEL); + if (!dma_safe_buf) + return -ENOMEM; + + ret = spi_nor_read_sfdp(nor, addr, len, dma_safe_buf); + memcpy(buf, dma_safe_buf, len); + kfree(dma_safe_buf); + + return ret; +} + struct sfdp_parameter_header { u8 id_lsb; u8 minor; @@ -2101,7 +2131,7 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor, bfpt_header->length * sizeof(u32)); addr = SFDP_PARAM_HEADER_PTP(bfpt_header); memset(&bfpt, 0, sizeof(bfpt)); - err = spi_nor_read_sfdp(nor, addr, len, &bfpt); + err = spi_nor_read_sfdp_dma_unsafe(nor, addr, len, &bfpt); if (err < 0) return err; @@ -2127,6 +2157,15 @@ static int spi_nor_parse_bfpt(struct spi_nor *nor, params->size = bfpt.dwords[BFPT_DWORD(2)]; if (params->size & BIT(31)) { params->size &= ~BIT(31); + + /* + * Prevent overflows on params->size. Anyway, a NOR of 2^64 + * bits is unlikely to exist so this error probably means + * the BFPT we are reading is corrupted/wrong. + */ + if (params->size > 63) + return -EINVAL; + params->size = 1ULL << params->size; } else { params->size++; @@ -2243,7 +2282,7 @@ static int spi_nor_parse_sfdp(struct spi_nor *nor, int i, err; /* Get the SFDP header. */ - err = spi_nor_read_sfdp(nor, 0, sizeof(header), &header); + err = spi_nor_read_sfdp_dma_unsafe(nor, 0, sizeof(header), &header); if (err < 0) return err; |