Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 page table isolation updates from Thomas Gleixner:
 "This is the final set of enabling page table isolation on x86:

   - Infrastructure patches for handling the extra page tables.

   - Patches which map the various bits and pieces which are required to
     get in and out of user space into the user space visible page
     tables.

   - The required changes to have CR3 switching in the entry/exit code.

   - Optimizations for the CR3 switching along with documentation how
     the ASID/PCID mechanism works.

   - Updates to dump pagetables to cover the user space page tables for
     W+X scans and extra debugfs files to analyze both the kernel and
     the user space visible page tables

  The whole functionality is compile time controlled via a config switch
  and can be turned on/off on the command line as well"

* 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (32 commits)
  x86/ldt: Make the LDT mapping RO
  x86/mm/dump_pagetables: Allow dumping current pagetables
  x86/mm/dump_pagetables: Check user space page table for WX pages
  x86/mm/dump_pagetables: Add page table directory to the debugfs VFS hierarchy
  x86/mm/pti: Add Kconfig
  x86/dumpstack: Indicate in Oops whether PTI is configured and enabled
  x86/mm: Clarify the whole ASID/kernel PCID/user PCID naming
  x86/mm: Use INVPCID for __native_flush_tlb_single()
  x86/mm: Optimize RESTORE_CR3
  x86/mm: Use/Fix PCID to optimize user/kernel switches
  x86/mm: Abstract switching CR3
  x86/mm: Allow flushing for future ASID switches
  x86/pti: Map the vsyscall page if needed
  x86/pti: Put the LDT in its own PGD if PTI is on
  x86/mm/64: Make a full PGD-entry size hole in the memory map
  x86/events/intel/ds: Map debug buffers in cpu_entry_area
  x86/cpu_entry_area: Add debugstore entries to cpu_entry_area
  x86/mm/pti: Map ESPFIX into user space
  x86/mm/pti: Share entry text PMD
  x86/entry: Align entry text section to PMD boundary
  ...

1 files changed, 74 insertions, 6 deletions

diff --git a/arch/x86/mm/debug_pagetables.c b/arch/x86/mm/debug_pagetables.c
index bfcffdf6c577..421f2664ffa0 100644
--- a/arch/x86/mm/debug_pagetables.c
+++ b/arch/x86/mm/debug_pagetables.c
@@ -5,7 +5,7 @@
 
 static int ptdump_show(struct seq_file *m, void *v)
 {
-	ptdump_walk_pgd_level(m, NULL);
+	ptdump_walk_pgd_level_debugfs(m, NULL, false);
 	return 0;
 }
 
@@ -22,21 +22,89 @@ static const struct file_operations ptdump_fops = {
 	.release	= single_release,
 };
 
-static struct dentry *pe;
+static int ptdump_show_curknl(struct seq_file *m, void *v)
+{
+	if (current->mm->pgd) {
+		down_read(&current->mm->mmap_sem);
+		ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, false);
+		up_read(&current->mm->mmap_sem);
+	}
+	return 0;
+}
+
+static int ptdump_open_curknl(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, ptdump_show_curknl, NULL);
+}
+
+static const struct file_operations ptdump_curknl_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ptdump_open_curknl,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+static struct dentry *pe_curusr;
+
+static int ptdump_show_curusr(struct seq_file *m, void *v)
+{
+	if (current->mm->pgd) {
+		down_read(&current->mm->mmap_sem);
+		ptdump_walk_pgd_level_debugfs(m, current->mm->pgd, true);
+		up_read(&current->mm->mmap_sem);
+	}
+	return 0;
+}
+
+static int ptdump_open_curusr(struct inode *inode, struct file *filp)
+{
+	return single_open(filp, ptdump_show_curusr, NULL);
+}
+
+static const struct file_operations ptdump_curusr_fops = {
+	.owner		= THIS_MODULE,
+	.open		= ptdump_open_curusr,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= single_release,
+};
+#endif
+
+static struct dentry *dir, *pe_knl, *pe_curknl;
 
 static int __init pt_dump_debug_init(void)
 {
-	pe = debugfs_create_file("kernel_page_tables", S_IRUSR, NULL, NULL,
-				 &ptdump_fops);
-	if (!pe)
+	dir = debugfs_create_dir("page_tables", NULL);
+	if (!dir)
 		return -ENOMEM;
 
+	pe_knl = debugfs_create_file("kernel", 0400, dir, NULL,
+				     &ptdump_fops);
+	if (!pe_knl)
+		goto err;
+
+	pe_curknl = debugfs_create_file("current_kernel", 0400,
+					dir, NULL, &ptdump_curknl_fops);
+	if (!pe_curknl)
+		goto err;
+
+#ifdef CONFIG_PAGE_TABLE_ISOLATION
+	pe_curusr = debugfs_create_file("current_user", 0400,
+					dir, NULL, &ptdump_curusr_fops);
+	if (!pe_curusr)
+		goto err;
+#endif
 	return 0;
+err:
+	debugfs_remove_recursive(dir);
+	return -ENOMEM;
 }
 
 static void __exit pt_dump_debug_exit(void)
 {
-	debugfs_remove_recursive(pe);
+	debugfs_remove_recursive(dir);
 }
 
 module_init(pt_dump_debug_init);