043d07084b
The noexec support on s390 does not rely on a bit in the page table entry but utilizes the secondary space mode to distinguish between memory accesses for instructions vs. data. The noexec code relies on the assumption that the cpu will always use the secondary space page table for data accesses while it is running in the secondary space mode. Up to the z9-109 class machines this has been the case. Unfortunately this is not true anymore with z10 and later machines. The load-relative-long instructions lrl, lgrl and lgfrl access the memory operand using the same addressing-space mode that has been used to fetch the instruction. This breaks the noexec mode for all user space binaries compiled with march=z10 or later. The only option is to remove the current noexec support. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
149 lines
3.7 KiB
C
149 lines
3.7 KiB
C
/*
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* IBM System z Huge TLB Page Support for Kernel.
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*
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* Copyright IBM Corp. 2008
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* Author(s): Gerald Schaefer <gerald.schaefer@de.ibm.com>
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*/
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#ifndef _ASM_S390_HUGETLB_H
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#define _ASM_S390_HUGETLB_H
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#define is_hugepage_only_range(mm, addr, len) 0
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#define hugetlb_free_pgd_range free_pgd_range
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void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
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pte_t *ptep, pte_t pte);
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/*
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* If the arch doesn't supply something else, assume that hugepage
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* size aligned regions are ok without further preparation.
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*/
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static inline int prepare_hugepage_range(struct file *file,
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unsigned long addr, unsigned long len)
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{
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if (len & ~HPAGE_MASK)
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return -EINVAL;
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if (addr & ~HPAGE_MASK)
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return -EINVAL;
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return 0;
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}
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#define hugetlb_prefault_arch_hook(mm) do { } while (0)
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int arch_prepare_hugepage(struct page *page);
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void arch_release_hugepage(struct page *page);
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static inline pte_t huge_pte_wrprotect(pte_t pte)
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{
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pte_val(pte) |= _PAGE_RO;
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return pte;
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}
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static inline int huge_pte_none(pte_t pte)
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{
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return (pte_val(pte) & _SEGMENT_ENTRY_INV) &&
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!(pte_val(pte) & _SEGMENT_ENTRY_RO);
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}
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static inline pte_t huge_ptep_get(pte_t *ptep)
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{
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pte_t pte = *ptep;
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unsigned long mask;
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if (!MACHINE_HAS_HPAGE) {
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ptep = (pte_t *) (pte_val(pte) & _SEGMENT_ENTRY_ORIGIN);
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if (ptep) {
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mask = pte_val(pte) &
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(_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
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pte = pte_mkhuge(*ptep);
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pte_val(pte) |= mask;
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}
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}
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return pte;
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}
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static inline pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
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unsigned long addr, pte_t *ptep)
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{
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pte_t pte = huge_ptep_get(ptep);
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mm->context.flush_mm = 1;
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pmd_clear((pmd_t *) ptep);
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return pte;
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}
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static inline void __pmd_csp(pmd_t *pmdp)
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{
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register unsigned long reg2 asm("2") = pmd_val(*pmdp);
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register unsigned long reg3 asm("3") = pmd_val(*pmdp) |
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_SEGMENT_ENTRY_INV;
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register unsigned long reg4 asm("4") = ((unsigned long) pmdp) + 5;
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asm volatile(
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" csp %1,%3"
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: "=m" (*pmdp)
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: "d" (reg2), "d" (reg3), "d" (reg4), "m" (*pmdp) : "cc");
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pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
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}
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static inline void __pmd_idte(unsigned long address, pmd_t *pmdp)
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{
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unsigned long sto = (unsigned long) pmdp -
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pmd_index(address) * sizeof(pmd_t);
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if (!(pmd_val(*pmdp) & _SEGMENT_ENTRY_INV)) {
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asm volatile(
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" .insn rrf,0xb98e0000,%2,%3,0,0"
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: "=m" (*pmdp)
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: "m" (*pmdp), "a" (sto),
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"a" ((address & HPAGE_MASK))
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);
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}
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pmd_val(*pmdp) = _SEGMENT_ENTRY_INV | _SEGMENT_ENTRY;
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}
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static inline void huge_ptep_invalidate(struct mm_struct *mm,
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unsigned long address, pte_t *ptep)
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{
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pmd_t *pmdp = (pmd_t *) ptep;
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if (MACHINE_HAS_IDTE)
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__pmd_idte(address, pmdp);
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else
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__pmd_csp(pmdp);
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}
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#define huge_ptep_set_access_flags(__vma, __addr, __ptep, __entry, __dirty) \
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({ \
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int __changed = !pte_same(huge_ptep_get(__ptep), __entry); \
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if (__changed) { \
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huge_ptep_invalidate((__vma)->vm_mm, __addr, __ptep); \
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set_huge_pte_at((__vma)->vm_mm, __addr, __ptep, __entry); \
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} \
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__changed; \
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})
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#define huge_ptep_set_wrprotect(__mm, __addr, __ptep) \
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({ \
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pte_t __pte = huge_ptep_get(__ptep); \
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if (pte_write(__pte)) { \
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(__mm)->context.flush_mm = 1; \
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if (atomic_read(&(__mm)->context.attach_count) > 1 || \
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(__mm) != current->active_mm) \
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huge_ptep_invalidate(__mm, __addr, __ptep); \
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set_huge_pte_at(__mm, __addr, __ptep, \
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huge_pte_wrprotect(__pte)); \
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} \
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})
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static inline void huge_ptep_clear_flush(struct vm_area_struct *vma,
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unsigned long address, pte_t *ptep)
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{
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huge_ptep_invalidate(vma->vm_mm, address, ptep);
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}
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#endif /* _ASM_S390_HUGETLB_H */
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