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-rw-r--r--arch/s390/include/asm/gmap.h3
-rw-r--r--arch/s390/mm/gmap.c60
2 files changed, 57 insertions, 6 deletions
diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index c1bc5633fc6e..276268b48aff 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -13,6 +13,9 @@
#define GMAP_NOTIFY_SHADOW 0x2
#define GMAP_NOTIFY_MPROT 0x1
+/* Status bits only for huge segment entries */
+#define _SEGMENT_ENTRY_GMAP_IN 0x8000 /* invalidation notify bit */
+
/**
* struct gmap_struct - guest address space
* @list: list head for the mm->context gmap list
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index 870e81fcb0cf..96dd94d51ad4 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -912,6 +912,40 @@ static inline void gmap_pmd_op_end(struct gmap *gmap, pmd_t *pmdp)
}
/*
+ * gmap_protect_pmd - remove access rights to memory and set pmd notification bits
+ * @pmdp: pointer to the pmd to be protected
+ * @prot: indicates access rights: PROT_NONE, PROT_READ or PROT_WRITE
+ * @bits: notification bits to set
+ *
+ * Returns:
+ * 0 if successfully protected
+ * -EAGAIN if a fixup is needed
+ * -EINVAL if unsupported notifier bits have been specified
+ *
+ * Expected to be called with sg->mm->mmap_sem in read and
+ * guest_table_lock held.
+ */
+static int gmap_protect_pmd(struct gmap *gmap, unsigned long gaddr,
+ pmd_t *pmdp, int prot, unsigned long bits)
+{
+ int pmd_i = pmd_val(*pmdp) & _SEGMENT_ENTRY_INVALID;
+ int pmd_p = pmd_val(*pmdp) & _SEGMENT_ENTRY_PROTECT;
+
+ /* Fixup needed */
+ if ((pmd_i && (prot != PROT_NONE)) || (pmd_p && (prot == PROT_WRITE)))
+ return -EAGAIN;
+
+ if (bits & GMAP_NOTIFY_MPROT)
+ pmd_val(*pmdp) |= _SEGMENT_ENTRY_GMAP_IN;
+
+ /* Shadow GMAP protection needs split PMDs */
+ if (bits & GMAP_NOTIFY_SHADOW)
+ return -EINVAL;
+
+ return 0;
+}
+
+/*
* gmap_protect_pte - remove access rights to memory and set pgste bits
* @gmap: pointer to guest mapping meta data structure
* @gaddr: virtual address in the guest address space
@@ -963,7 +997,7 @@ static int gmap_protect_pte(struct gmap *gmap, unsigned long gaddr,
static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
unsigned long len, int prot, unsigned long bits)
{
- unsigned long vmaddr;
+ unsigned long vmaddr, dist;
pmd_t *pmdp;
int rc;
@@ -972,15 +1006,29 @@ static int gmap_protect_range(struct gmap *gmap, unsigned long gaddr,
rc = -EAGAIN;
pmdp = gmap_pmd_op_walk(gmap, gaddr);
if (pmdp) {
- rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
- bits);
- if (!rc) {
- len -= PAGE_SIZE;
- gaddr += PAGE_SIZE;
+ if (!pmd_large(*pmdp)) {
+ rc = gmap_protect_pte(gmap, gaddr, pmdp, prot,
+ bits);
+ if (!rc) {
+ len -= PAGE_SIZE;
+ gaddr += PAGE_SIZE;
+ }
+ } else {
+ rc = gmap_protect_pmd(gmap, gaddr, pmdp, prot,
+ bits);
+ if (!rc) {
+ dist = HPAGE_SIZE - (gaddr & ~HPAGE_MASK);
+ len = len < dist ? 0 : len - dist;
+ gaddr = (gaddr & HPAGE_MASK) + HPAGE_SIZE;
+ }
}
gmap_pmd_op_end(gmap, pmdp);
}
if (rc) {
+ if (rc == -EINVAL)
+ return rc;
+
+ /* -EAGAIN, fixup of userspace mm and gmap */
vmaddr = __gmap_translate(gmap, gaddr);
if (IS_ERR_VALUE(vmaddr))
return vmaddr;