linux_dsm_epyc7002/arch/powerpc/include/asm/pgtable.h
Russell Currey 453d87f6a8 powerpc/mm: Warn if W+X pages found on boot
Implement code to walk all pages and warn if any are found to be both
writable and executable.  Depends on STRICT_KERNEL_RWX enabled, and is
behind the DEBUG_WX config option.

This only runs on boot and has no runtime performance implications.

Very heavily influenced (and in some cases copied verbatim) from the
ARM64 code written by Laura Abbott (thanks!), since our ptdump
infrastructure is similar.

Signed-off-by: Russell Currey <ruscur@russell.cc>
[mpe: Fixup build error when disabled]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
2019-05-03 02:54:45 +10:00

146 lines
3.5 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_POWERPC_PGTABLE_H
#define _ASM_POWERPC_PGTABLE_H
#ifndef __ASSEMBLY__
#include <linux/mmdebug.h>
#include <linux/mmzone.h>
#include <asm/processor.h> /* For TASK_SIZE */
#include <asm/mmu.h>
#include <asm/page.h>
#include <asm/tlbflush.h>
struct mm_struct;
#endif /* !__ASSEMBLY__ */
#ifdef CONFIG_PPC_BOOK3S
#include <asm/book3s/pgtable.h>
#else
#include <asm/nohash/pgtable.h>
#endif /* !CONFIG_PPC_BOOK3S */
/* Note due to the way vm flags are laid out, the bits are XWR */
#define __P000 PAGE_NONE
#define __P001 PAGE_READONLY
#define __P010 PAGE_COPY
#define __P011 PAGE_COPY
#define __P100 PAGE_READONLY_X
#define __P101 PAGE_READONLY_X
#define __P110 PAGE_COPY_X
#define __P111 PAGE_COPY_X
#define __S000 PAGE_NONE
#define __S001 PAGE_READONLY
#define __S010 PAGE_SHARED
#define __S011 PAGE_SHARED
#define __S100 PAGE_READONLY_X
#define __S101 PAGE_READONLY_X
#define __S110 PAGE_SHARED_X
#define __S111 PAGE_SHARED_X
#ifndef __ASSEMBLY__
#include <asm/tlbflush.h>
/* Keep these as a macros to avoid include dependency mess */
#define pte_page(x) pfn_to_page(pte_pfn(x))
#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot))
/*
* Select all bits except the pfn
*/
static inline pgprot_t pte_pgprot(pte_t pte)
{
unsigned long pte_flags;
pte_flags = pte_val(pte) & ~PTE_RPN_MASK;
return __pgprot(pte_flags);
}
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
*/
extern unsigned long empty_zero_page[];
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
extern pgd_t swapper_pg_dir[];
extern void paging_init(void);
/*
* kern_addr_valid is intended to indicate whether an address is a valid
* kernel address. Most 32-bit archs define it as always true (like this)
* but most 64-bit archs actually perform a test. What should we do here?
*/
#define kern_addr_valid(addr) (1)
#include <asm-generic/pgtable.h>
/*
* This gets called at the end of handling a page fault, when
* the kernel has put a new PTE into the page table for the process.
* We use it to ensure coherency between the i-cache and d-cache
* for the page which has just been mapped in.
* On machines which use an MMU hash table, we use this to put a
* corresponding HPTE into the hash table ahead of time, instead of
* waiting for the inevitable extra hash-table miss exception.
*/
extern void update_mmu_cache(struct vm_area_struct *, unsigned long, pte_t *);
#ifndef CONFIG_TRANSPARENT_HUGEPAGE
#define pmd_large(pmd) 0
#endif
/* can we use this in kvm */
unsigned long vmalloc_to_phys(void *vmalloc_addr);
void pgtable_cache_add(unsigned int shift);
void pgtable_cache_init(void);
#if defined(CONFIG_STRICT_KERNEL_RWX) || defined(CONFIG_PPC32)
void mark_initmem_nx(void);
#else
static inline void mark_initmem_nx(void) { }
#endif
#ifdef CONFIG_PPC_DEBUG_WX
void ptdump_check_wx(void);
#else
static inline void ptdump_check_wx(void) { }
#endif
/*
* When used, PTE_FRAG_NR is defined in subarch pgtable.h
* so we are sure it is included when arriving here.
*/
#ifdef PTE_FRAG_NR
static inline void *pte_frag_get(mm_context_t *ctx)
{
return ctx->pte_frag;
}
static inline void pte_frag_set(mm_context_t *ctx, void *p)
{
ctx->pte_frag = p;
}
#else
#define PTE_FRAG_NR 1
#define PTE_FRAG_SIZE_SHIFT PAGE_SHIFT
#define PTE_FRAG_SIZE (1UL << PTE_FRAG_SIZE_SHIFT)
static inline void *pte_frag_get(mm_context_t *ctx)
{
return NULL;
}
static inline void pte_frag_set(mm_context_t *ctx, void *p)
{
}
#endif
#endif /* __ASSEMBLY__ */
#endif /* _ASM_POWERPC_PGTABLE_H */