1 files changed, 20 insertions, 44 deletions

diff --git a/arch/s390/kernel/vdso.c b/arch/s390/kernel/vdso.c
index eacda05b45d7..39a218703c50 100644
--- a/arch/s390/kernel/vdso.c
+++ b/arch/s390/kernel/vdso.c
@@ -140,20 +140,27 @@ static void __init vdso_init_data(struct vdso_data *vd)
  */
 #define SEGMENT_ORDER	2
 
+/*
+ * The initial vdso_data structure for the boot CPU. Eventually
+ * it is replaced with a properly allocated structure in vdso_init.
+ * This is necessary because a valid S390_lowcore.vdso_per_cpu_data
+ * pointer is required to be able to return from an interrupt or
+ * program check. See the exit paths in entry.S.
+ */
+struct vdso_data boot_vdso_data __initdata;
+
+void __init vdso_alloc_boot_cpu(struct lowcore *lowcore)
+{
+	lowcore->vdso_per_cpu_data = (unsigned long) &boot_vdso_data;
+}
+
 int vdso_alloc_per_cpu(struct lowcore *lowcore)
 {
 	unsigned long segment_table, page_table, page_frame;
 	struct vdso_per_cpu_data *vd;
-	u32 *psal, *aste;
-	int i;
-
-	lowcore->vdso_per_cpu_data = __LC_PASTE;
-
-	if (!vdso_enabled)
-		return 0;
 
 	segment_table = __get_free_pages(GFP_KERNEL, SEGMENT_ORDER);
-	page_table = get_zeroed_page(GFP_KERNEL | GFP_DMA);
+	page_table = get_zeroed_page(GFP_KERNEL);
 	page_frame = get_zeroed_page(GFP_KERNEL);
 	if (!segment_table || !page_table || !page_frame)
 		goto out;
@@ -165,27 +172,15 @@ int vdso_alloc_per_cpu(struct lowcore *lowcore)
 	vd->cpu_nr = lowcore->cpu_nr;
 	vd->node_id = cpu_to_node(vd->cpu_nr);
 
-	/* Set up access register mode page table */
-	clear_table((unsigned long *) segment_table, _SEGMENT_ENTRY_EMPTY,
-		    PAGE_SIZE << SEGMENT_ORDER);
-	clear_table((unsigned long *) page_table, _PAGE_INVALID,
-		    256*sizeof(unsigned long));
+	/* Set up page table for the vdso address space */
+	memset64((u64 *)segment_table, _SEGMENT_ENTRY_EMPTY, _CRST_ENTRIES);
+	memset64((u64 *)page_table, _PAGE_INVALID, PTRS_PER_PTE);
 
 	*(unsigned long *) segment_table = _SEGMENT_ENTRY + page_table;
 	*(unsigned long *) page_table = _PAGE_PROTECT + page_frame;
 
-	psal = (u32 *) (page_table + 256*sizeof(unsigned long));
-	aste = psal + 32;
-
-	for (i = 4; i < 32; i += 4)
-		psal[i] = 0x80000000;
-
-	lowcore->paste[4] = (u32)(addr_t) psal;
-	psal[0] = 0x02000000;
-	psal[2] = (u32)(addr_t) aste;
-	*(unsigned long *) (aste + 2) = segment_table +
+	lowcore->vdso_asce = segment_table +
 		_ASCE_TABLE_LENGTH + _ASCE_USER_BITS + _ASCE_TYPE_SEGMENT;
-	aste[4] = (u32)(addr_t) psal;
 	lowcore->vdso_per_cpu_data = page_frame;
 
 	return 0;
@@ -200,14 +195,8 @@ out:
 void vdso_free_per_cpu(struct lowcore *lowcore)
 {
 	unsigned long segment_table, page_table, page_frame;
-	u32 *psal, *aste;
-
-	if (!vdso_enabled)
-		return;
 
-	psal = (u32 *)(addr_t) lowcore->paste[4];
-	aste = (u32 *)(addr_t) psal[2];
-	segment_table = *(unsigned long *)(aste + 2) & PAGE_MASK;
+	segment_table = lowcore->vdso_asce & PAGE_MASK;
 	page_table = *(unsigned long *) segment_table;
 	page_frame = *(unsigned long *) page_table;
 
@@ -216,16 +205,6 @@ void vdso_free_per_cpu(struct lowcore *lowcore)
 	free_pages(segment_table, SEGMENT_ORDER);
 }
 
-static void vdso_init_cr5(void)
-{
-	unsigned long cr5;
-
-	if (!vdso_enabled)
-		return;
-	cr5 = offsetof(struct lowcore, paste);
-	__ctl_load(cr5, 5, 5);
-}
-
 /*
  * This is called from binfmt_elf, we create the special vma for the
  * vDSO and insert it into the mm struct tree
@@ -302,8 +281,6 @@ static int __init vdso_init(void)
 {
 	int i;
 
-	if (!vdso_enabled)
-		return 0;
 	vdso_init_data(vdso_data);
 #ifdef CONFIG_COMPAT
 	/* Calculate the size of the 32 bit vDSO */
@@ -342,7 +319,6 @@ static int __init vdso_init(void)
 	vdso64_pagelist[vdso64_pages] = NULL;
 	if (vdso_alloc_per_cpu(&S390_lowcore))
 		BUG();
-	vdso_init_cr5();
 
 	get_page(virt_to_page(vdso_data));