platform/x86: dcdbas: Check SMBIOS for protected buffer address (47a94c55) · Commits · 戴 / test

drivers/platform/x86/dcdbas.c

+30 −13

Original line number	Diff line number	Diff line
		@@ -15,6 +15,7 @@
		#include <linux/platform_device.h>
		#include <linux/acpi.h>
		#include <linux/dma-mapping.h>
		#include <linux/dmi.h>
		#include <linux/errno.h>
		#include <linux/cpu.h>
		#include <linux/gfp.h>
		@@ -34,7 +35,7 @@
		#include "dcdbas.h"

		#define DRIVER_NAME "dcdbas"
		#define DRIVER_VERSION "5.6.0-3.3"
		#define DRIVER_VERSION "5.6.0-3.4"
		#define DRIVER_DESCRIPTION "Dell Systems Management Base Driver"

		static struct platform_device *dcdbas_pdev;
		@@ -45,7 +46,7 @@ static unsigned long smi_data_buf_size;
		static unsigned long max_smi_data_buf_size = MAX_SMI_DATA_BUF_SIZE;
		static u32 smi_data_buf_phys_addr;
		static DEFINE_MUTEX(smi_data_lock);
		static u8 *eps_buffer;
		static u8 *bios_buffer;

		static unsigned int host_control_action;
		static unsigned int host_control_smi_type;
		@@ -518,8 +519,10 @@ static inline struct smm_eps_table check_eps_table(u8 addr)

		static int dcdbas_check_wsmt(void)
		{
		const struct dmi_device *dev = NULL;
		struct acpi_table_wsmt *wsmt = NULL;
		struct smm_eps_table *eps = NULL;
		u64 bios_buf_paddr;
		u64 remap_size;
		u8 *addr;

		@@ -532,6 +535,17 @@ static int dcdbas_check_wsmt(void)
		!(wsmt->protection_flags & ACPI_WSMT_COMM_BUFFER_NESTED_PTR_PROTECTION))
		return 0;

		/*
		* BIOS could provide the address/size of the protected buffer
		* in an SMBIOS string or in an EPS structure in 0xFxxxx.
		*/

		/* Check SMBIOS for buffer address */
		while ((dev = dmi_find_device(DMI_DEV_TYPE_OEM_STRING, NULL, dev)))
		if (sscanf(dev->name, "30[%16llx;%8llx]", &bios_buf_paddr,
		&remap_size) == 2)
		goto remap;

		/* Scan for EPS (entry point structure) */
		for (addr = (u8 *)__va(0xf0000);
		addr < (u8 *)__va(0x100000 - sizeof(struct smm_eps_table));
		@@ -542,34 +556,37 @@ static int dcdbas_check_wsmt(void)
		}

		if (!eps) {
		dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no EPS found\n");
		dev_dbg(&dcdbas_pdev->dev, "found WSMT, but no firmware buffer found\n");
		return -ENODEV;
		}
		bios_buf_paddr = eps->smm_comm_buff_addr;
		remap_size = eps->num_of_4k_pages * PAGE_SIZE;

		remap:
		/*
		* Get physical address of buffer and map to virtual address.
		* Table gives size in 4K pages, regardless of actual system page size.
		*/
		if (upper_32_bits(eps->smm_comm_buff_addr + 8)) {
		dev_warn(&dcdbas_pdev->dev, "found WSMT, but EPS buffer address is above 4GB\n");
		if (upper_32_bits(bios_buf_paddr + 8)) {
		dev_warn(&dcdbas_pdev->dev, "found WSMT, but buffer address is above 4GB\n");
		return -EINVAL;
		}
		/*
		* Limit remap size to MAX_SMI_DATA_BUF_SIZE + 8 (since the first 8
		* bytes are used for a semaphore, not the data buffer itself).
		*/
		remap_size = eps->num_of_4k_pages * PAGE_SIZE;
		if (remap_size > MAX_SMI_DATA_BUF_SIZE + 8)
		remap_size = MAX_SMI_DATA_BUF_SIZE + 8;
		eps_buffer = memremap(eps->smm_comm_buff_addr, remap_size, MEMREMAP_WB);
		if (!eps_buffer) {
		dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map EPS buffer\n");

		bios_buffer = memremap(bios_buf_paddr, remap_size, MEMREMAP_WB);
		if (!bios_buffer) {
		dev_warn(&dcdbas_pdev->dev, "found WSMT, but failed to map buffer\n");
		return -ENOMEM;
		}

		/* First 8 bytes is for a semaphore, not part of the smi_data_buf */
		smi_data_buf_phys_addr = eps->smm_comm_buff_addr + 8;
		smi_data_buf = eps_buffer + 8;
		smi_data_buf_phys_addr = bios_buf_paddr + 8;
		smi_data_buf = bios_buffer + 8;
		smi_data_buf_size = remap_size - 8;
		max_smi_data_buf_size = smi_data_buf_size;
		wsmt_enabled = true;
		@@ -736,8 +753,8 @@ static void __exit dcdbas_exit(void)
		*/
		if (dcdbas_pdev)
		smi_data_buf_free();
		if (eps_buffer)
		memunmap(eps_buffer);
		if (bios_buffer)
		memunmap(bios_buffer);
		platform_device_unregister(dcdbas_pdev_reg);
		platform_driver_unregister(&dcdbas_driver);
		}

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