Commit d3ab332a authored by Zong Li's avatar Zong Li Committed by Palmer Dabbelt

riscv: add ARCH_HAS_SET_MEMORY support

Add set_memory_ro/rw/x/nx architecture hooks to change the page
attribution.

Use own set_memory.h rather than generic set_memory.h
(i.e. include/asm-generic/set_memory.h), because we want to add other
function prototypes here.
Signed-off-by: default avatarZong Li <zong.li@sifive.com>
Signed-off-by: default avatarPalmer Dabbelt <palmerdabbelt@google.com>
parent 9f40b6e7
...@@ -59,6 +59,7 @@ config RISCV ...@@ -59,6 +59,7 @@ config RISCV
select HAVE_EBPF_JIT if 64BIT select HAVE_EBPF_JIT if 64BIT
select EDAC_SUPPORT select EDAC_SUPPORT
select ARCH_HAS_GIGANTIC_PAGE select ARCH_HAS_GIGANTIC_PAGE
select ARCH_HAS_SET_MEMORY
select ARCH_WANT_HUGE_PMD_SHARE if 64BIT select ARCH_WANT_HUGE_PMD_SHARE if 64BIT
select SPARSEMEM_STATIC if 32BIT select SPARSEMEM_STATIC if 32BIT
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU
......
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2019 SiFive
*/
#ifndef _ASM_RISCV_SET_MEMORY_H
#define _ASM_RISCV_SET_MEMORY_H
/*
* Functions to change memory attributes.
*/
#ifdef CONFIG_MMU
int set_memory_ro(unsigned long addr, int numpages);
int set_memory_rw(unsigned long addr, int numpages);
int set_memory_x(unsigned long addr, int numpages);
int set_memory_nx(unsigned long addr, int numpages);
#else
static inline int set_memory_ro(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_rw(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_x(unsigned long addr, int numpages) { return 0; }
static inline int set_memory_nx(unsigned long addr, int numpages) { return 0; }
#endif
#endif /* _ASM_RISCV_SET_MEMORY_H */
...@@ -7,7 +7,7 @@ endif ...@@ -7,7 +7,7 @@ endif
obj-y += init.o obj-y += init.o
obj-y += extable.o obj-y += extable.o
obj-$(CONFIG_MMU) += fault.o obj-$(CONFIG_MMU) += fault.o pageattr.o
obj-y += cacheflush.o obj-y += cacheflush.o
obj-y += context.o obj-y += context.o
......
// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2019 SiFive
*/
#include <linux/pagewalk.h>
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
#include <asm/bitops.h>
struct pageattr_masks {
pgprot_t set_mask;
pgprot_t clear_mask;
};
static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
{
struct pageattr_masks *masks = walk->private;
unsigned long new_val = val;
new_val &= ~(pgprot_val(masks->clear_mask));
new_val |= (pgprot_val(masks->set_mask));
return new_val;
}
static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pgd_t val = READ_ONCE(*pgd);
if (pgd_leaf(val)) {
val = __pgd(set_pageattr_masks(pgd_val(val), walk));
set_pgd(pgd, val);
}
return 0;
}
static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
p4d_t val = READ_ONCE(*p4d);
if (p4d_leaf(val)) {
val = __p4d(set_pageattr_masks(p4d_val(val), walk));
set_p4d(p4d, val);
}
return 0;
}
static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pud_t val = READ_ONCE(*pud);
if (pud_leaf(val)) {
val = __pud(set_pageattr_masks(pud_val(val), walk));
set_pud(pud, val);
}
return 0;
}
static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pmd_t val = READ_ONCE(*pmd);
if (pmd_leaf(val)) {
val = __pmd(set_pageattr_masks(pmd_val(val), walk));
set_pmd(pmd, val);
}
return 0;
}
static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
unsigned long next, struct mm_walk *walk)
{
pte_t val = READ_ONCE(*pte);
val = __pte(set_pageattr_masks(pte_val(val), walk));
set_pte(pte, val);
return 0;
}
static int pageattr_pte_hole(unsigned long addr, unsigned long next,
int depth, struct mm_walk *walk)
{
/* Nothing to do here */
return 0;
}
const static struct mm_walk_ops pageattr_ops = {
.pgd_entry = pageattr_pgd_entry,
.p4d_entry = pageattr_p4d_entry,
.pud_entry = pageattr_pud_entry,
.pmd_entry = pageattr_pmd_entry,
.pte_entry = pageattr_pte_entry,
.pte_hole = pageattr_pte_hole,
};
static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
pgprot_t clear_mask)
{
int ret;
unsigned long start = addr;
unsigned long end = start + PAGE_SIZE * numpages;
struct pageattr_masks masks = {
.set_mask = set_mask,
.clear_mask = clear_mask
};
if (!numpages)
return 0;
down_read(&init_mm.mmap_sem);
ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
&masks);
up_read(&init_mm.mmap_sem);
flush_tlb_kernel_range(start, end);
return ret;
}
int set_memory_ro(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(_PAGE_READ),
__pgprot(_PAGE_WRITE));
}
int set_memory_rw(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE),
__pgprot(0));
}
int set_memory_x(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(_PAGE_EXEC), __pgprot(0));
}
int set_memory_nx(unsigned long addr, int numpages)
{
return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
}
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