summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorQiaowei Ren <qiaowei.ren@intel.com>2013-06-24 13:55:33 +0800
committerIngo Molnar <mingo@kernel.org>2013-06-28 11:05:16 +0200
commit13bfd47a0ef68fc8b21e67873dbdf269c7db6b59 (patch)
tree31ba961110515e7a60fb1278b9ea4603b7594ec2
parent5a802e15308f152247433d87050d1bfbf9613483 (diff)
x86/tboot: Provide debugfs interfaces to access TXT log
These logs come from tboot (Trusted Boot, an open source, pre-kernel/VMM module that uses Intel TXT to perform a measured and verified launch of an OS kernel/VMM.). Signed-off-by: Qiaowei Ren <qiaowei.ren@intel.com> Acked-by: H. Peter Anvin <hpa@zytor.com> Cc: Gang Wei <gang.wei@intel.com> Link: http://lkml.kernel.org/r/1372053333-21788-1-git-send-email-qiaowei.ren@intel.com [ Beautified the code a bit. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--arch/x86/kernel/tboot.c73
1 files changed, 73 insertions, 0 deletions
diff --git a/arch/x86/kernel/tboot.c b/arch/x86/kernel/tboot.c
index f84fe00fad48..3ff42d2f046d 100644
--- a/arch/x86/kernel/tboot.c
+++ b/arch/x86/kernel/tboot.c
@@ -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;
}