[PATCH 25/30] x86, kaiser: add debugfs file to turn KAISER on/off at runtime

[Dave Hansen]

From: Dave Hansen 

This will be used in a few patches.  Right now, it's not wired up
to do anything useful.

Signed-off-by: Dave Hansen 
Cc: Moritz Lipp 
Cc: Daniel Gruss 
Cc: Michael Schwarz 
Cc: Richard Fellner 
Cc: Andy Lutomirski 
Cc: Linus Torvalds 
Cc: Kees Cook 
Cc: Hugh Dickins 
Cc: x...@kernel.org
---

 b/arch/x86/mm/kaiser.c |   48 
 1 file changed, 48 insertions(+)

diff -puN arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs arch/x86/mm/kaiser.c
--- a/arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs   2017-11-10 
11:22:18.900244925 -0800
+++ b/arch/x86/mm/kaiser.c  2017-11-10 11:22:18.904244925 -0800
@@ -29,6 +29,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -457,3 +458,50 @@ void kaiser_remove_mapping(unsigned long
 */
__native_flush_tlb_global();
 }
+
+int kaiser_enabled = 1;
+static ssize_t kaiser_enabled_read_file(struct file *file, char __user 
*user_buf,
+size_t count, loff_t *ppos)
+{
+   char buf[32];
+   unsigned int len;
+
+   len = sprintf(buf, "%d\n", kaiser_enabled);
+   return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t kaiser_enabled_write_file(struct file *file,
+const char __user *user_buf, size_t count, loff_t *ppos)
+{
+   char buf[32];
+   ssize_t len;
+   unsigned int enable;
+
+   len = min(count, sizeof(buf) - 1);
+   if (copy_from_user(buf, user_buf, len))
+   return -EFAULT;
+
+   buf[len] = '\0';
+   if (kstrtoint(buf, 0, ))
+   return -EINVAL;
+
+   if (enable > 1)
+   return -EINVAL;
+
+   WRITE_ONCE(kaiser_enabled, enable);
+   return count;
+}
+
+static const struct file_operations fops_kaiser_enabled = {
+   .read = kaiser_enabled_read_file,
+   .write = kaiser_enabled_write_file,
+   .llseek = default_llseek,
+};
+
+static int __init create_kaiser_enabled(void)
+{
+   debugfs_create_file("kaiser-enabled", S_IRUSR | S_IWUSR,
+   arch_debugfs_dir, NULL, _kaiser_enabled);
+   return 0;
+}
+late_initcall(create_kaiser_enabled);
_

[PATCH 25/30] x86, kaiser: add debugfs file to turn KAISER on/off at runtime

[Dave Hansen]

From: Dave Hansen 

This will be used in a few patches.  Right now, it's not wired up
to do anything useful.

Signed-off-by: Dave Hansen 
Cc: Moritz Lipp 
Cc: Daniel Gruss 
Cc: Michael Schwarz 
Cc: Richard Fellner 
Cc: Andy Lutomirski 
Cc: Linus Torvalds 
Cc: Kees Cook 
Cc: Hugh Dickins 
Cc: x...@kernel.org
---

 b/arch/x86/mm/kaiser.c |   48 
 1 file changed, 48 insertions(+)

diff -puN arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs arch/x86/mm/kaiser.c
--- a/arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs   2017-11-10 
11:22:18.900244925 -0800
+++ b/arch/x86/mm/kaiser.c  2017-11-10 11:22:18.904244925 -0800
@@ -29,6 +29,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -457,3 +458,50 @@ void kaiser_remove_mapping(unsigned long
 */
__native_flush_tlb_global();
 }
+
+int kaiser_enabled = 1;
+static ssize_t kaiser_enabled_read_file(struct file *file, char __user 
*user_buf,
+size_t count, loff_t *ppos)
+{
+   char buf[32];
+   unsigned int len;
+
+   len = sprintf(buf, "%d\n", kaiser_enabled);
+   return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t kaiser_enabled_write_file(struct file *file,
+const char __user *user_buf, size_t count, loff_t *ppos)
+{
+   char buf[32];
+   ssize_t len;
+   unsigned int enable;
+
+   len = min(count, sizeof(buf) - 1);
+   if (copy_from_user(buf, user_buf, len))
+   return -EFAULT;
+
+   buf[len] = '\0';
+   if (kstrtoint(buf, 0, ))
+   return -EINVAL;
+
+   if (enable > 1)
+   return -EINVAL;
+
+   WRITE_ONCE(kaiser_enabled, enable);
+   return count;
+}
+
+static const struct file_operations fops_kaiser_enabled = {
+   .read = kaiser_enabled_read_file,
+   .write = kaiser_enabled_write_file,
+   .llseek = default_llseek,
+};
+
+static int __init create_kaiser_enabled(void)
+{
+   debugfs_create_file("kaiser-enabled", S_IRUSR | S_IWUSR,
+   arch_debugfs_dir, NULL, _kaiser_enabled);
+   return 0;
+}
+late_initcall(create_kaiser_enabled);
_

[PATCH 25/30] x86, kaiser: add debugfs file to turn KAISER on/off at runtime

[Dave Hansen]

From: Dave Hansen 

We will use this in a few patches.  Right now, it's not wired up
to do anything useful.

Signed-off-by: Dave Hansen 
Cc: Moritz Lipp 
Cc: Daniel Gruss 
Cc: Michael Schwarz 
Cc: Richard Fellner 
Cc: Andy Lutomirski 
Cc: Linus Torvalds 
Cc: Kees Cook 
Cc: Hugh Dickins 
Cc: x...@kernel.org
---

 b/arch/x86/mm/kaiser.c |   48 
 1 file changed, 48 insertions(+)

diff -puN arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs arch/x86/mm/kaiser.c
--- a/arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs   2017-11-08 
10:45:39.690681369 -0800
+++ b/arch/x86/mm/kaiser.c  2017-11-08 10:45:39.693681369 -0800
@@ -18,6 +18,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -446,3 +447,50 @@ void kaiser_remove_mapping(unsigned long
 */
__native_flush_tlb_global();
 }
+
+int kaiser_enabled = 1;
+static ssize_t kaiser_enabled_read_file(struct file *file, char __user 
*user_buf,
+size_t count, loff_t *ppos)
+{
+   char buf[32];
+   unsigned int len;
+
+   len = sprintf(buf, "%d\n", kaiser_enabled);
+   return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t kaiser_enabled_write_file(struct file *file,
+const char __user *user_buf, size_t count, loff_t *ppos)
+{
+   char buf[32];
+   ssize_t len;
+   unsigned int enable;
+
+   len = min(count, sizeof(buf) - 1);
+   if (copy_from_user(buf, user_buf, len))
+   return -EFAULT;
+
+   buf[len] = '\0';
+   if (kstrtoint(buf, 0, ))
+   return -EINVAL;
+
+   if (enable > 1)
+   return -EINVAL;
+
+   WRITE_ONCE(kaiser_enabled, enable);
+   return count;
+}
+
+static const struct file_operations fops_kaiser_enabled = {
+   .read = kaiser_enabled_read_file,
+   .write = kaiser_enabled_write_file,
+   .llseek = default_llseek,
+};
+
+static int __init create_kaiser_enabled(void)
+{
+   debugfs_create_file("kaiser-enabled", S_IRUSR | S_IWUSR,
+   arch_debugfs_dir, NULL, _kaiser_enabled);
+   return 0;
+}
+late_initcall(create_kaiser_enabled);
_

[PATCH 25/30] x86, kaiser: add debugfs file to turn KAISER on/off at runtime

[Dave Hansen]

From: Dave Hansen 

We will use this in a few patches.  Right now, it's not wired up
to do anything useful.

Signed-off-by: Dave Hansen 
Cc: Moritz Lipp 
Cc: Daniel Gruss 
Cc: Michael Schwarz 
Cc: Richard Fellner 
Cc: Andy Lutomirski 
Cc: Linus Torvalds 
Cc: Kees Cook 
Cc: Hugh Dickins 
Cc: x...@kernel.org
---

 b/arch/x86/mm/kaiser.c |   48 
 1 file changed, 48 insertions(+)

diff -puN arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs arch/x86/mm/kaiser.c
--- a/arch/x86/mm/kaiser.c~kaiser-dynamic-debugfs   2017-11-08 
10:45:39.690681369 -0800
+++ b/arch/x86/mm/kaiser.c  2017-11-08 10:45:39.693681369 -0800
@@ -18,6 +18,7 @@
 #include 
 #include 
 #include 
+#include 
 #include 
 #include 
 #include 
@@ -446,3 +447,50 @@ void kaiser_remove_mapping(unsigned long
 */
__native_flush_tlb_global();
 }
+
+int kaiser_enabled = 1;
+static ssize_t kaiser_enabled_read_file(struct file *file, char __user 
*user_buf,
+size_t count, loff_t *ppos)
+{
+   char buf[32];
+   unsigned int len;
+
+   len = sprintf(buf, "%d\n", kaiser_enabled);
+   return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static ssize_t kaiser_enabled_write_file(struct file *file,
+const char __user *user_buf, size_t count, loff_t *ppos)
+{
+   char buf[32];
+   ssize_t len;
+   unsigned int enable;
+
+   len = min(count, sizeof(buf) - 1);
+   if (copy_from_user(buf, user_buf, len))
+   return -EFAULT;
+
+   buf[len] = '\0';
+   if (kstrtoint(buf, 0, ))
+   return -EINVAL;
+
+   if (enable > 1)
+   return -EINVAL;
+
+   WRITE_ONCE(kaiser_enabled, enable);
+   return count;
+}
+
+static const struct file_operations fops_kaiser_enabled = {
+   .read = kaiser_enabled_read_file,
+   .write = kaiser_enabled_write_file,
+   .llseek = default_llseek,
+};
+
+static int __init create_kaiser_enabled(void)
+{
+   debugfs_create_file("kaiser-enabled", S_IRUSR | S_IWUSR,
+   arch_debugfs_dir, NULL, _kaiser_enabled);
+   return 0;
+}
+late_initcall(create_kaiser_enabled);
_