x86/mm/32: implement arch_sync_kernel_mappings()

Implement the function to sync changes in vmalloc and ioremap ranges to all page-tables. Signed-off-by: Joerg Roedel <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Acked-by: Andy Lutomirski <[email protected]> Acked-by: Peter Zijlstra (Intel) <[email protected]> Cc: Arnd Bergmann <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Dave Hansen <[email protected]> Cc: "H . Peter Anvin" <[email protected]> Cc: Ingo Molnar <[email protected]> Cc: Matthew Wilcox (Oracle) <[email protected]> Cc: Michal Hocko <[email protected]> Cc: "Rafael J. Wysocki" <[email protected]> Cc: Steven Rostedt (VMware) <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: Vlastimil Babka <[email protected]> Link: http://lkml.kernel.org/r/[email protected] Signed-off-by: Linus Torvalds <[email protected]>
Rust-for-Linux · Jun 2, 2020 · 86cf69f · 86cf69f
1 parent 8e19843
commit 86cf69f
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Showing 3 changed files with 20 additions and 9 deletions.
diff --git a/arch/x86/include/asm/pgtable-2level_types.h b/arch/x86/include/asm/pgtable-2level_types.h
@@ -20,6 +20,8 @@ typedef union {
 
 #define SHARED_KERNEL_PMD	0
 
+#define ARCH_PAGE_TABLE_SYNC_MASK	PGTBL_PMD_MODIFIED
+
 /*
  * traditional i386 two-level paging structure:
  */

diff --git a/arch/x86/include/asm/pgtable-3level_types.h b/arch/x86/include/asm/pgtable-3level_types.h
@@ -27,6 +27,8 @@ typedef union {
 #define SHARED_KERNEL_PMD	(!static_cpu_has(X86_FEATURE_PTI))
 #endif
 
+#define ARCH_PAGE_TABLE_SYNC_MASK	(SHARED_KERNEL_PMD ? 0 : PGTBL_PMD_MODIFIED)
+
 /*
  * PGDIR_SHIFT determines what a top-level page table entry can map
  */

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
@@ -190,16 +190,13 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address)
 	return pmd_k;
 }
 
-static void vmalloc_sync(void)
+void arch_sync_kernel_mappings(unsigned long start, unsigned long end)
 {
-	unsigned long address;
-
-	if (SHARED_KERNEL_PMD)
-		return;
+	unsigned long addr;
 
-	for (address = VMALLOC_START & PMD_MASK;
-	     address >= TASK_SIZE_MAX && address < VMALLOC_END;
-	     address += PMD_SIZE) {
+	for (addr = start & PMD_MASK;
+	     addr >= TASK_SIZE_MAX && addr < VMALLOC_END;
+	     addr += PMD_SIZE) {
 		struct page *page;
 
 		spin_lock(&pgd_lock);
@@ -210,13 +207,23 @@ static void vmalloc_sync(void)
 			pgt_lock = &pgd_page_get_mm(page)->page_table_lock;
 
 			spin_lock(pgt_lock);
-			vmalloc_sync_one(page_address(page), address);
+			vmalloc_sync_one(page_address(page), addr);
 			spin_unlock(pgt_lock);
 		}
 		spin_unlock(&pgd_lock);
 	}
 }
 
+static void vmalloc_sync(void)
+{
+	unsigned long address;
+
+	if (SHARED_KERNEL_PMD)
+		return;
+
+	arch_sync_kernel_mappings(VMALLOC_START, VMALLOC_END);
+}
+
 void vmalloc_sync_mappings(void)
 {
 	vmalloc_sync();