Merge branch 'x86/pti-urgent' into x86/pti

Integrate the PTI Global bit fixes which conflict with the 32bit PTI
support.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 25 insertions, 11 deletions

diff --git a/arch/x86/mm/pti.c b/arch/x86/mm/pti.c
index bcf35dac1920..ef8db6ffc836 100644
--- a/arch/x86/mm/pti.c
+++ b/arch/x86/mm/pti.c
@@ -470,6 +470,13 @@ static inline bool pti_kernel_image_global_ok(void)
 }
 
 /*
+ * This is the only user for these and it is not arch-generic
+ * like the other set_memory.h functions.  Just extern them.
+ */
+extern int set_memory_nonglobal(unsigned long addr, int numpages);
+extern int set_memory_global(unsigned long addr, int numpages);
+
+/*
  * For some configurations, map all of kernel text into the user page
  * tables.  This reduces TLB misses, especially on non-PCID systems.
  */
@@ -481,7 +488,8 @@ static void pti_clone_kernel_text(void)
 	 * clone the areas past rodata, they might contain secrets.
 	 */
 	unsigned long start = PFN_ALIGN(_text);
-	unsigned long end = (unsigned long)__end_rodata_aligned;
+	unsigned long end_clone  = (unsigned long)__end_rodata_aligned;
+	unsigned long end_global = PFN_ALIGN((unsigned long)__stop___ex_table);
 
 	if (!pti_kernel_image_global_ok())
 		return;
@@ -493,15 +501,19 @@ static void pti_clone_kernel_text(void)
 	 * pti_set_kernel_image_nonglobal() did to clear the
 	 * global bit.
 	 */
-	pti_clone_pmds(start, end, 0);
+	pti_clone_pmds(start, end_clone, _PAGE_RW);
+
+	/*
+	 * pti_clone_pmds() will set the global bit in any PMDs
+	 * that it clones, but we also need to get any PTEs in
+	 * the last level for areas that are not huge-page-aligned.
+	 */
+
+	/* Set the global bit for normal non-__init kernel text: */
+	set_memory_global(start, (end_global - start) >> PAGE_SHIFT);
 }
 
-/*
- * This is the only user for it and it is not arch-generic like
- * the other set_memory.h functions.  Just extern it.
- */
-extern int set_memory_nonglobal(unsigned long addr, int numpages);
-static void pti_set_kernel_image_nonglobal(void)
+void pti_set_kernel_image_nonglobal(void)
 {
 	/*
 	 * The identity map is created with PMDs, regardless of the
@@ -512,9 +524,11 @@ static void pti_set_kernel_image_nonglobal(void)
 	unsigned long start = PFN_ALIGN(_text);
 	unsigned long end = ALIGN((unsigned long)_end, PMD_PAGE_SIZE);
 
-	if (pti_kernel_image_global_ok())
-		return;
-
+	/*
+	 * This clears _PAGE_GLOBAL from the entire kernel image.
+	 * pti_clone_kernel_text() map put _PAGE_GLOBAL back for
+	 * areas that are mapped to userspace.
+	 */
 	set_memory_nonglobal(start, (end - start) >> PAGE_SHIFT);
 }