From: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Date: Wed, 11 Apr 2018 12:13:31 +0530
Subject: [PATCH 1/2] rsi: fix nommu_map_sg overflow kernel panic
Cc: linux-wireless@vger.kernel.org,
	Amitkumar Karwar <amit.karwar@redpinesignals.com>,
	Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>

Following overflow kernel panic is observed on some platforms while
loading the driver. It is fixed if dynamically allocated memory is
passed to SDIO instead of static one

[  927.513963] nommu_map_sg: overflow 17d54064ba7c+20 of device mask ffffffff
[  927.517712] Modules linked in: rsi_sdio(+) cmac bnep arc4 rsi_91x mac80211 cfg80211
	       btrsi rfcomm bluetooth ecdh_generic snd_soc_sst_bytcr_rt5660
[  927.517861] CPU: 0 PID: 1624 Comm: insmod Tainted: G W 4.15.0-1000 #1
[  927.517870] RIP: 0010:sdhci_send_command+0x5f0/0xa90 [sdhci]
[  927.517873] RSP: 0000:ffffac3fc064b6d8 EFLAGS: 00010086
[  927.517895] Call Trace:
[  927.517908]  ? __schedule+0x3cd/0x890
[  927.517915]  ? mod_timer+0x17b/0x3c0
[  927.517922]  sdhci_request+0x7c/0xf0 [sdhci]
[  927.517928]  __mmc_start_request+0x5a/0x170
[  927.517932]  mmc_start_request+0x74/0x90
[  927.517936]  mmc_wait_for_req+0x87/0xe0
[  927.517940]  mmc_io_rw_extended+0x2fd/0x330
[  927.517946]  ? mmc_wait_data_done+0x30/0x30
[  927.517951]  sdio_io_rw_ext_helper+0x160/0x210
[  927.517956]  sdio_writesb+0x1d/0x20
[  927.517966]	rsi_sdio_write_register_multiple+0x68/0x110 [rsi_sdio]
[  927.517976]  rsi_hal_device_init+0x357/0x910 [rsi_91x]
[  927.517983]  ? rsi_hal_device_init+0x357/0x910 [rsi_91x]
[  927.517990]  rsi_probe+0x2c6/0x450 [rsi_sdio]
[  927.517995]  sdio_bus_probe+0xfc/0x110
[  927.518000]  driver_probe_device+0x2b3/0x490
[  927.518005]  __driver_attach+0xdf/0xf0
[  927.518008]  ? driver_probe_device+0x490/0x490
[  927.518014]  bus_for_each_dev+0x6c/0xc0
[  927.518018]  driver_attach+0x1e/0x20
[  927.518021]  bus_add_driver+0x1f4/0x270
[  927.518028]  ? rsi_sdio_ack_intr+0x50/0x50 [rsi_sdio]
[  927.518031]  driver_register+0x60/0xe0
[  927.518038]  ? rsi_sdio_ack_intr+0x50/0x50 [rsi_sdio]
[  927.518041]  sdio_register_driver+0x20/0x30
[  927.518047]  rsi_module_init+0x16/0x40 [rsi_sdio]

Signed-off-by: Siva Rebbagondla <siva.rebbagondla@redpinesignals.com>
Signed-off-by: Amitkumar Karwar <amit.karwar@redpinesignals.com>
---
 drivers/net/wireless/rsi/rsi_91x_hal.c  | 35 ++++++++++++++++++++-------------
 drivers/net/wireless/rsi/rsi_91x_sdio.c | 21 +++++++++++++-------
 drivers/net/wireless/rsi/rsi_sdio.h     |  2 +-
 3 files changed, 36 insertions(+), 22 deletions(-)

diff --git a/drivers/net/wireless/rsi/rsi_91x_hal.c b/drivers/net/wireless/rsi/rsi_91x_hal.c
index b7c5403..0761e61 100644
--- a/drivers/net/wireless/rsi/rsi_91x_hal.c
+++ b/drivers/net/wireless/rsi/rsi_91x_hal.c
@@ -635,28 +635,32 @@ static int bl_write_header(struct rsi_hw *adapter, u8 *flash_content,
 			   u32 content_size)
 {
 	struct rsi_host_intf_ops *hif_ops = adapter->host_intf_ops;
-	struct bl_header bl_hdr;
+	struct bl_header *bl_hdr;
 	u32 write_addr, write_len;
 	int status;
 
-	bl_hdr.flags = 0;
-	bl_hdr.image_no = cpu_to_le32(adapter->priv->coex_mode);
-	bl_hdr.check_sum = cpu_to_le32(
-				*(u32 *)&flash_content[CHECK_SUM_OFFSET]);
-	bl_hdr.flash_start_address = cpu_to_le32(
-					*(u32 *)&flash_content[ADDR_OFFSET]);
-	bl_hdr.flash_len = cpu_to_le32(*(u32 *)&flash_content[LEN_OFFSET]);
+	bl_hdr = kzalloc(sizeof(*bl_hdr), GFP_KERNEL);
+	if (!bl_hdr)
+		return -ENOMEM;
+
+	bl_hdr->flags = 0;
+	bl_hdr->image_no = cpu_to_le32(adapter->priv->coex_mode);
+	bl_hdr->check_sum =
+		cpu_to_le32(*(u32 *)&flash_content[CHECK_SUM_OFFSET]);
+	bl_hdr->flash_start_address =
+		cpu_to_le32(*(u32 *)&flash_content[ADDR_OFFSET]);
+	bl_hdr->flash_len = cpu_to_le32(*(u32 *)&flash_content[LEN_OFFSET]);
 	write_len = sizeof(struct bl_header);
 
 	if (adapter->rsi_host_intf == RSI_HOST_INTF_USB) {
 		write_addr = PING_BUFFER_ADDRESS;
 		status = hif_ops->write_reg_multiple(adapter, write_addr,
-						 (u8 *)&bl_hdr, write_len);
+						 (u8 *)bl_hdr, write_len);
 		if (status < 0) {
 			rsi_dbg(ERR_ZONE,
 				"%s: Failed to load Version/CRC structure\n",
 				__func__);
-			return status;
+			goto fail;
 		}
 	} else {
 		write_addr = PING_BUFFER_ADDRESS >> 16;
@@ -665,20 +669,23 @@ static int bl_write_header(struct rsi_hw *adapter, u8 *flash_content,
 			rsi_dbg(ERR_ZONE,
 				"%s: Unable to set ms word to common reg\n",
 				__func__);
-			return status;
+			goto fail;
 		}
 		write_addr = RSI_SD_REQUEST_MASTER |
 			     (PING_BUFFER_ADDRESS & 0xFFFF);
 		status = hif_ops->write_reg_multiple(adapter, write_addr,
-						 (u8 *)&bl_hdr, write_len);
+						 (u8 *)bl_hdr, write_len);
 		if (status < 0) {
 			rsi_dbg(ERR_ZONE,
 				"%s: Failed to load Version/CRC structure\n",
 				__func__);
-			return status;
+			goto fail;
 		}
 	}
-	return 0;
+	status = 0;
+fail:
+	kfree(bl_hdr);
+	return status;
 }
 
 static u32 read_flash_capacity(struct rsi_hw *adapter)
diff --git a/drivers/net/wireless/rsi/rsi_91x_sdio.c b/drivers/net/wireless/rsi/rsi_91x_sdio.c
index 8ef0058..f7f2820 100644
--- a/drivers/net/wireless/rsi/rsi_91x_sdio.c
+++ b/drivers/net/wireless/rsi/rsi_91x_sdio.c
@@ -1038,17 +1038,21 @@ static void ulp_read_write(struct rsi_hw *adapter, u16 addr, u32 data,
 /*This function resets and re-initializes the chip.*/
 static void rsi_reset_chip(struct rsi_hw *adapter)
 {
-	__le32 data;
+	u8 *data;
 	u8 sdio_interrupt_status = 0;
 	u8 request = 1;
 	int ret;
 
+	data = kzalloc(sizeof(u32), GFP_KERNEL);
+	if (!data)
+		return;
+
 	rsi_dbg(INFO_ZONE, "Writing disable to wakeup register\n");
 	ret =  rsi_sdio_write_register(adapter, 0, SDIO_WAKEUP_REG, &request);
 	if (ret < 0) {
 		rsi_dbg(ERR_ZONE,
 			"%s: Failed to write SDIO wakeup register\n", __func__);
-		return;
+		goto err;
 	}
 	msleep(20);
 	ret =  rsi_sdio_read_register(adapter, RSI_FN1_INT_REGISTER,
@@ -1056,7 +1060,7 @@ static void rsi_reset_chip(struct rsi_hw *adapter)
 	if (ret < 0) {
 		rsi_dbg(ERR_ZONE, "%s: Failed to Read Intr Status Register\n",
 			__func__);
-		return;
+		goto err;
 	}
 	rsi_dbg(INFO_ZONE, "%s: Intr Status Register value = %d\n",
 		__func__, sdio_interrupt_status);
@@ -1066,17 +1070,17 @@ static void rsi_reset_chip(struct rsi_hw *adapter)
 		rsi_dbg(ERR_ZONE,
 			"%s: Unable to set ms word to common reg\n",
 			__func__);
-		return;
+		goto err;
 	}
 
-	data = TA_HOLD_THREAD_VALUE;
+	put_unaligned_le32(TA_HOLD_THREAD_VALUE, data);
 	if (rsi_sdio_write_register_multiple(adapter, TA_HOLD_THREAD_REG |
 					     RSI_SD_REQUEST_MASTER,
-					     (u8 *)&data, 4)) {
+					     data, 4)) {
 		rsi_dbg(ERR_ZONE,
 			"%s: Unable to hold Thread-Arch processor threads\n",
 			__func__);
-		return;
+		goto err;
 	}
 
 	/* This msleep will ensure Thread-Arch processor to go to hold
@@ -1097,6 +1101,9 @@ static void rsi_reset_chip(struct rsi_hw *adapter)
 	 * read write operations to complete for chip reset.
 	 */
 	msleep(500);
+err:
+	kfree(data);
+	return;
 }
 
 /**
diff --git a/drivers/net/wireless/rsi/rsi_sdio.h b/drivers/net/wireless/rsi/rsi_sdio.h
index ead8e7c..353dbdf 100644
--- a/drivers/net/wireless/rsi/rsi_sdio.h
+++ b/drivers/net/wireless/rsi/rsi_sdio.h
@@ -87,7 +87,7 @@ enum sdio_interrupt_type {
 #define TA_SOFT_RST_CLR              0
 #define TA_SOFT_RST_SET              BIT(0)
 #define TA_PC_ZERO                   0
-#define TA_HOLD_THREAD_VALUE         cpu_to_le32(0xF)
+#define TA_HOLD_THREAD_VALUE         0xF
 #define TA_RELEASE_THREAD_VALUE      cpu_to_le32(0xF)
 #define TA_BASE_ADDR                 0x2200
 #define MISC_CFG_BASE_ADDR           0x4105