x86/tboot: Provide debugfs interfaces to access TXT log (13bfd47a) · Commits · 戴 / test

arch/x86/kernel/tboot.c

+73 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,7 @@
		#include <linux/pfn.h>
		#include <linux/mm.h>
		#include <linux/tboot.h>
		#include <linux/debugfs.h>

		#include <asm/realmode.h>
		#include <asm/processor.h>
		@@ -338,6 +339,73 @@ static struct notifier_block tboot_cpu_notifier __cpuinitdata =
		.notifier_call = tboot_cpu_callback,
		};

		#ifdef CONFIG_DEBUG_FS

		#define TBOOT_LOG_UUID { 0x26, 0x25, 0x19, 0xc0, 0x30, 0x6b, 0xb4, 0x4d, \
		0x4c, 0x84, 0xa3, 0xe9, 0x53, 0xb8, 0x81, 0x74 }

		#define TBOOT_SERIAL_LOG_ADDR 0x60000
		#define TBOOT_SERIAL_LOG_SIZE 0x08000
		#define LOG_MAX_SIZE_OFF 16
		#define LOG_BUF_OFF 24

		static uint8_t tboot_log_uuid[16] = TBOOT_LOG_UUID;

		static ssize_t tboot_log_read(struct file file, char __user user_buf, size_t count, loff_t *ppos)
		{
		void __iomem *log_base;
		u8 log_uuid[16];
		u32 max_size;
		void *kbuf;
		int ret = -EFAULT;

		log_base = ioremap_nocache(TBOOT_SERIAL_LOG_ADDR, TBOOT_SERIAL_LOG_SIZE);
		if (!log_base)
		return ret;

		memcpy_fromio(log_uuid, log_base, sizeof(log_uuid));
		if (memcmp(&tboot_log_uuid, log_uuid, sizeof(log_uuid)))
		goto err_iounmap;

		max_size = readl(log_base + LOG_MAX_SIZE_OFF);
		if (*ppos >= max_size) {
		ret = 0;
		goto err_iounmap;
		}

		if (*ppos + count > max_size)
		count = max_size - *ppos;

		kbuf = kmalloc(count, GFP_KERNEL);
		if (!kbuf) {
		ret = -ENOMEM;
		goto err_iounmap;
		}

		memcpy_fromio(kbuf, log_base + LOG_BUF_OFF + *ppos, count);
		if (copy_to_user(user_buf, kbuf, count))
		goto err_kfree;

		*ppos += count;

		ret = count;

		err_kfree:
		kfree(kbuf);

		err_iounmap:
		iounmap(log_base);

		return ret;
		}

		static const struct file_operations tboot_log_fops = {
		.read = tboot_log_read,
		.llseek = default_llseek,
		};

		#endif /* CONFIG_DEBUG_FS */

		static __init int tboot_late_init(void)
		{
		if (!tboot_enabled())
		@@ -348,6 +416,11 @@ static __init int tboot_late_init(void)
		atomic_set(&ap_wfs_count, 0);
		register_hotcpu_notifier(&tboot_cpu_notifier);

		#ifdef CONFIG_DEBUG_FS
		debugfs_create_file("tboot_log", S_IRUSR,
		arch_debugfs_dir, NULL, &tboot_log_fops);
		#endif

		acpi_os_set_prepare_sleep(&tboot_sleep);
		return 0;
		}

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