diff options
| -rw-r--r-- | arch/s390/include/asm/gmap.h | 3 | ||||
| -rw-r--r-- | arch/s390/mm/gmap.c | 60 |
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; |