linux_dsm_epyc7002/arch/s390/include/asm/pgalloc.h
Martin Schwidefsky 043d07084b [S390] Remove data execution protection
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>
2011-05-23 10:24:28 +02:00

164 lines
4.4 KiB
C

/*
* include/asm-s390/pgalloc.h
*
* S390 version
* Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com)
* Martin Schwidefsky (schwidefsky@de.ibm.com)
*
* Derived from "include/asm-i386/pgalloc.h"
* Copyright (C) 1994 Linus Torvalds
*/
#ifndef _S390_PGALLOC_H
#define _S390_PGALLOC_H
#include <linux/threads.h>
#include <linux/gfp.h>
#include <linux/mm.h>
#define check_pgt_cache() do {} while (0)
unsigned long *crst_table_alloc(struct mm_struct *);
void crst_table_free(struct mm_struct *, unsigned long *);
void crst_table_free_rcu(struct mm_struct *, unsigned long *);
unsigned long *page_table_alloc(struct mm_struct *);
void page_table_free(struct mm_struct *, unsigned long *);
void page_table_free_rcu(struct mm_struct *, unsigned long *);
static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
{
typedef struct { char _[n]; } addrtype;
*s = val;
n = (n / 256) - 1;
asm volatile(
#ifdef CONFIG_64BIT
" mvc 8(248,%0),0(%0)\n"
#else
" mvc 4(252,%0),0(%0)\n"
#endif
"0: mvc 256(256,%0),0(%0)\n"
" la %0,256(%0)\n"
" brct %1,0b\n"
: "+a" (s), "+d" (n), "=m" (*(addrtype *) s)
: "m" (*(addrtype *) s));
}
static inline void crst_table_init(unsigned long *crst, unsigned long entry)
{
clear_table(crst, entry, sizeof(unsigned long)*2048);
}
#ifndef __s390x__
static inline unsigned long pgd_entry_type(struct mm_struct *mm)
{
return _SEGMENT_ENTRY_EMPTY;
}
#define pud_alloc_one(mm,address) ({ BUG(); ((pud_t *)2); })
#define pud_free(mm, x) do { } while (0)
#define pmd_alloc_one(mm,address) ({ BUG(); ((pmd_t *)2); })
#define pmd_free(mm, x) do { } while (0)
#define pgd_populate(mm, pgd, pud) BUG()
#define pgd_populate_kernel(mm, pgd, pud) BUG()
#define pud_populate(mm, pud, pmd) BUG()
#define pud_populate_kernel(mm, pud, pmd) BUG()
#else /* __s390x__ */
static inline unsigned long pgd_entry_type(struct mm_struct *mm)
{
if (mm->context.asce_limit <= (1UL << 31))
return _SEGMENT_ENTRY_EMPTY;
if (mm->context.asce_limit <= (1UL << 42))
return _REGION3_ENTRY_EMPTY;
return _REGION2_ENTRY_EMPTY;
}
int crst_table_upgrade(struct mm_struct *, unsigned long limit);
void crst_table_downgrade(struct mm_struct *, unsigned long limit);
static inline pud_t *pud_alloc_one(struct mm_struct *mm, unsigned long address)
{
unsigned long *table = crst_table_alloc(mm);
if (table)
crst_table_init(table, _REGION3_ENTRY_EMPTY);
return (pud_t *) table;
}
#define pud_free(mm, pud) crst_table_free(mm, (unsigned long *) pud)
static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long vmaddr)
{
unsigned long *table = crst_table_alloc(mm);
if (table)
crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
return (pmd_t *) table;
}
#define pmd_free(mm, pmd) crst_table_free(mm, (unsigned long *) pmd)
static inline void pgd_populate_kernel(struct mm_struct *mm,
pgd_t *pgd, pud_t *pud)
{
pgd_val(*pgd) = _REGION2_ENTRY | __pa(pud);
}
static inline void pgd_populate(struct mm_struct *mm, pgd_t *pgd, pud_t *pud)
{
pgd_populate_kernel(mm, pgd, pud);
}
static inline void pud_populate_kernel(struct mm_struct *mm,
pud_t *pud, pmd_t *pmd)
{
pud_val(*pud) = _REGION3_ENTRY | __pa(pmd);
}
static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
{
pud_populate_kernel(mm, pud, pmd);
}
#endif /* __s390x__ */
static inline pgd_t *pgd_alloc(struct mm_struct *mm)
{
spin_lock_init(&mm->context.list_lock);
INIT_LIST_HEAD(&mm->context.pgtable_list);
return (pgd_t *) crst_table_alloc(mm);
}
#define pgd_free(mm, pgd) crst_table_free(mm, (unsigned long *) pgd)
static inline void pmd_populate_kernel(struct mm_struct *mm,
pmd_t *pmd, pte_t *pte)
{
pmd_val(*pmd) = _SEGMENT_ENTRY + __pa(pte);
}
static inline void pmd_populate(struct mm_struct *mm,
pmd_t *pmd, pgtable_t pte)
{
pmd_populate_kernel(mm, pmd, pte);
}
#define pmd_pgtable(pmd) \
(pgtable_t)(pmd_val(pmd) & -sizeof(pte_t)*PTRS_PER_PTE)
/*
* page table entry allocation/free routines.
*/
#define pte_alloc_one_kernel(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
#define pte_alloc_one(mm, vmaddr) ((pte_t *) page_table_alloc(mm))
#define pte_free_kernel(mm, pte) page_table_free(mm, (unsigned long *) pte)
#define pte_free(mm, pte) page_table_free(mm, (unsigned long *) pte)
extern void rcu_table_freelist_finish(void);
#endif /* _S390_PGALLOC_H */