/*
|
/*
|
* linux/mm/memory.c
|
* linux/mm/memory.c
|
*
|
*
|
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
|
* Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
|
*/
|
*/
|
|
|
/*
|
/*
|
* demand-loading started 01.12.91 - seems it is high on the list of
|
* demand-loading started 01.12.91 - seems it is high on the list of
|
* things wanted, and it should be easy to implement. - Linus
|
* things wanted, and it should be easy to implement. - Linus
|
*/
|
*/
|
|
|
/*
|
/*
|
* Ok, demand-loading was easy, shared pages a little bit tricker. Shared
|
* Ok, demand-loading was easy, shared pages a little bit tricker. Shared
|
* pages started 02.12.91, seems to work. - Linus.
|
* pages started 02.12.91, seems to work. - Linus.
|
*
|
*
|
* Tested sharing by executing about 30 /bin/sh: under the old kernel it
|
* Tested sharing by executing about 30 /bin/sh: under the old kernel it
|
* would have taken more than the 6M I have free, but it worked well as
|
* would have taken more than the 6M I have free, but it worked well as
|
* far as I could see.
|
* far as I could see.
|
*
|
*
|
* Also corrected some "invalidate()"s - I wasn't doing enough of them.
|
* Also corrected some "invalidate()"s - I wasn't doing enough of them.
|
*/
|
*/
|
|
|
/*
|
/*
|
* Real VM (paging to/from disk) started 18.12.91. Much more work and
|
* Real VM (paging to/from disk) started 18.12.91. Much more work and
|
* thought has to go into this. Oh, well..
|
* thought has to go into this. Oh, well..
|
* 19.12.91 - works, somewhat. Sometimes I get faults, don't know why.
|
* 19.12.91 - works, somewhat. Sometimes I get faults, don't know why.
|
* Found it. Everything seems to work now.
|
* Found it. Everything seems to work now.
|
* 20.12.91 - Ok, making the swap-device changeable like the root.
|
* 20.12.91 - Ok, making the swap-device changeable like the root.
|
*/
|
*/
|
|
|
/*
|
/*
|
* 05.04.94 - Multi-page memory management added for v1.1.
|
* 05.04.94 - Multi-page memory management added for v1.1.
|
* Idea by Alex Bligh (alex@cconcepts.co.uk)
|
* Idea by Alex Bligh (alex@cconcepts.co.uk)
|
*/
|
*/
|
|
|
#include <linux/signal.h>
|
#include <linux/signal.h>
|
#include <linux/sched.h>
|
#include <linux/sched.h>
|
#include <linux/head.h>
|
#include <linux/head.h>
|
#include <linux/kernel.h>
|
#include <linux/kernel.h>
|
#include <linux/errno.h>
|
#include <linux/errno.h>
|
#include <linux/string.h>
|
#include <linux/string.h>
|
#include <linux/types.h>
|
#include <linux/types.h>
|
#include <linux/ptrace.h>
|
#include <linux/ptrace.h>
|
#include <linux/mman.h>
|
#include <linux/mman.h>
|
#include <linux/mm.h>
|
#include <linux/mm.h>
|
#include <linux/swap.h>
|
#include <linux/swap.h>
|
|
|
#include <asm/system.h>
|
#include <asm/system.h>
|
#include <asm/segment.h>
|
#include <asm/segment.h>
|
#include <asm/pgtable.h>
|
#include <asm/pgtable.h>
|
#include <asm/string.h>
|
#include <asm/string.h>
|
|
|
unsigned long high_memory = 0;
|
unsigned long high_memory = 0;
|
|
|
/*
|
/*
|
* We special-case the C-O-W ZERO_PAGE, because it's such
|
* We special-case the C-O-W ZERO_PAGE, because it's such
|
* a common occurrence (no need to read the page to know
|
* a common occurrence (no need to read the page to know
|
* that it's zero - better for the cache and memory subsystem).
|
* that it's zero - better for the cache and memory subsystem).
|
*/
|
*/
|
static inline void copy_page(unsigned long from, unsigned long to)
|
static inline void copy_page(unsigned long from, unsigned long to)
|
{
|
{
|
if (from == ZERO_PAGE) {
|
if (from == ZERO_PAGE) {
|
memset((void *) to, 0, PAGE_SIZE);
|
memset((void *) to, 0, PAGE_SIZE);
|
return;
|
return;
|
}
|
}
|
memcpy((void *) to, (void *) from, PAGE_SIZE);
|
memcpy((void *) to, (void *) from, PAGE_SIZE);
|
}
|
}
|
|
|
#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
|
#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
|
|
|
mem_map_t * mem_map = NULL;
|
mem_map_t * mem_map = NULL;
|
|
|
/*
|
/*
|
* oom() prints a message (so that the user knows why the process died),
|
* oom() prints a message (so that the user knows why the process died),
|
* and gives the process an untrappable SIGKILL.
|
* and gives the process an untrappable SIGKILL.
|
*/
|
*/
|
void oom(struct task_struct * task)
|
void oom(struct task_struct * task)
|
{
|
{
|
printk("\nOut of memory for %s.\n", task->comm);
|
printk("\nOut of memory for %s.\n", task->comm);
|
task->sig->action[SIGKILL-1].sa_handler = NULL;
|
task->sig->action[SIGKILL-1].sa_handler = NULL;
|
task->blocked &= ~(1<<(SIGKILL-1));
|
task->blocked &= ~(1<<(SIGKILL-1));
|
send_sig(SIGKILL,task,1);
|
send_sig(SIGKILL,task,1);
|
}
|
}
|
|
|
/*
|
/*
|
* Note: this doesn't free the actual pages themselves. That
|
* Note: this doesn't free the actual pages themselves. That
|
* has been handled earlier when unmapping all the memory regions.
|
* has been handled earlier when unmapping all the memory regions.
|
*/
|
*/
|
static inline void free_one_pmd(pmd_t * dir)
|
static inline void free_one_pmd(pmd_t * dir)
|
{
|
{
|
pte_t * pte;
|
pte_t * pte;
|
|
|
if (pmd_none(*dir))
|
if (pmd_none(*dir))
|
return;
|
return;
|
if (pmd_bad(*dir)) {
|
if (pmd_bad(*dir)) {
|
printk("free_one_pmd: bad directory entry %08lx\n", pmd_val(*dir));
|
printk("free_one_pmd: bad directory entry %08lx\n", pmd_val(*dir));
|
pmd_clear(dir);
|
pmd_clear(dir);
|
return;
|
return;
|
}
|
}
|
pte = pte_offset(dir, 0);
|
pte = pte_offset(dir, 0);
|
pmd_clear(dir);
|
pmd_clear(dir);
|
pte_free(pte);
|
pte_free(pte);
|
}
|
}
|
|
|
static inline void free_one_pgd(pgd_t * dir)
|
static inline void free_one_pgd(pgd_t * dir)
|
{
|
{
|
int j;
|
int j;
|
pmd_t * pmd;
|
pmd_t * pmd;
|
|
|
if (pgd_none(*dir))
|
if (pgd_none(*dir))
|
return;
|
return;
|
if (pgd_bad(*dir)) {
|
if (pgd_bad(*dir)) {
|
printk("free_one_pgd: bad directory entry %08lx\n", pgd_val(*dir));
|
printk("free_one_pgd: bad directory entry %08lx\n", pgd_val(*dir));
|
pgd_clear(dir);
|
pgd_clear(dir);
|
return;
|
return;
|
}
|
}
|
pmd = pmd_offset(dir, 0);
|
pmd = pmd_offset(dir, 0);
|
pgd_clear(dir);
|
pgd_clear(dir);
|
for (j = 0; j < PTRS_PER_PMD ; j++)
|
for (j = 0; j < PTRS_PER_PMD ; j++)
|
free_one_pmd(pmd+j);
|
free_one_pmd(pmd+j);
|
pmd_free(pmd);
|
pmd_free(pmd);
|
}
|
}
|
|
|
/*
|
/*
|
* This function clears all user-level page tables of a process - this
|
* This function clears all user-level page tables of a process - this
|
* is needed by execve(), so that old pages aren't in the way.
|
* is needed by execve(), so that old pages aren't in the way.
|
*/
|
*/
|
void clear_page_tables(struct task_struct * tsk)
|
void clear_page_tables(struct task_struct * tsk)
|
{
|
{
|
int i;
|
int i;
|
pgd_t * page_dir;
|
pgd_t * page_dir;
|
|
|
page_dir = tsk->mm->pgd;
|
page_dir = tsk->mm->pgd;
|
if (!page_dir || page_dir == swapper_pg_dir) {
|
if (!page_dir || page_dir == swapper_pg_dir) {
|
printk("%s trying to clear kernel page-directory: not good\n", tsk->comm);
|
printk("%s trying to clear kernel page-directory: not good\n", tsk->comm);
|
return;
|
return;
|
}
|
}
|
flush_cache_mm(tsk->mm);
|
flush_cache_mm(tsk->mm);
|
for (i = 0 ; i < USER_PTRS_PER_PGD ; i++)
|
for (i = 0 ; i < USER_PTRS_PER_PGD ; i++)
|
free_one_pgd(page_dir + i);
|
free_one_pgd(page_dir + i);
|
flush_tlb_mm(tsk->mm);
|
flush_tlb_mm(tsk->mm);
|
}
|
}
|
|
|
/*
|
/*
|
* This function frees up all page tables of a process when it exits. It
|
* This function frees up all page tables of a process when it exits. It
|
* is the same as "clear_page_tables()", except it also changes the process'
|
* is the same as "clear_page_tables()", except it also changes the process'
|
* page table directory to the kernel page tables and then frees the old
|
* page table directory to the kernel page tables and then frees the old
|
* page table directory.
|
* page table directory.
|
*/
|
*/
|
void free_page_tables(struct mm_struct * mm)
|
void free_page_tables(struct mm_struct * mm)
|
{
|
{
|
int i;
|
int i;
|
pgd_t * page_dir;
|
pgd_t * page_dir;
|
|
|
page_dir = mm->pgd;
|
page_dir = mm->pgd;
|
if (!page_dir || page_dir == swapper_pg_dir) {
|
if (!page_dir || page_dir == swapper_pg_dir) {
|
printk("Trying to free kernel page-directory: not good\n");
|
printk("Trying to free kernel page-directory: not good\n");
|
return;
|
return;
|
}
|
}
|
for (i = 0 ; i < USER_PTRS_PER_PGD ; i++)
|
for (i = 0 ; i < USER_PTRS_PER_PGD ; i++)
|
free_one_pgd(page_dir + i);
|
free_one_pgd(page_dir + i);
|
pgd_free(page_dir);
|
pgd_free(page_dir);
|
}
|
}
|
|
|
int new_page_tables(struct task_struct * tsk)
|
int new_page_tables(struct task_struct * tsk)
|
{
|
{
|
pgd_t * page_dir, * new_pg;
|
pgd_t * page_dir, * new_pg;
|
|
|
if (!(new_pg = pgd_alloc()))
|
if (!(new_pg = pgd_alloc()))
|
return -ENOMEM;
|
return -ENOMEM;
|
page_dir = pgd_offset(&init_mm, 0);
|
page_dir = pgd_offset(&init_mm, 0);
|
flush_cache_mm(tsk->mm);
|
flush_cache_mm(tsk->mm);
|
memcpy(new_pg + USER_PTRS_PER_PGD, page_dir + USER_PTRS_PER_PGD,
|
memcpy(new_pg + USER_PTRS_PER_PGD, page_dir + USER_PTRS_PER_PGD,
|
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof (pgd_t));
|
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof (pgd_t));
|
flush_tlb_mm(tsk->mm);
|
flush_tlb_mm(tsk->mm);
|
SET_PAGE_DIR(tsk, new_pg);
|
SET_PAGE_DIR(tsk, new_pg);
|
tsk->mm->pgd = new_pg;
|
tsk->mm->pgd = new_pg;
|
return 0;
|
return 0;
|
}
|
}
|
|
|
static inline void copy_one_pte(pte_t * old_pte, pte_t * new_pte, int cow)
|
static inline void copy_one_pte(pte_t * old_pte, pte_t * new_pte, int cow)
|
{
|
{
|
pte_t pte = *old_pte;
|
pte_t pte = *old_pte;
|
unsigned long page_nr;
|
unsigned long page_nr;
|
|
|
if (pte_none(pte))
|
if (pte_none(pte))
|
return;
|
return;
|
if (!pte_present(pte)) {
|
if (!pte_present(pte)) {
|
swap_duplicate(pte_val(pte));
|
swap_duplicate(pte_val(pte));
|
set_pte(new_pte, pte);
|
set_pte(new_pte, pte);
|
return;
|
return;
|
}
|
}
|
page_nr = MAP_NR(pte_page(pte));
|
page_nr = MAP_NR(pte_page(pte));
|
if (page_nr >= MAP_NR(high_memory) || PageReserved(mem_map+page_nr)) {
|
if (page_nr >= MAP_NR(high_memory) || PageReserved(mem_map+page_nr)) {
|
set_pte(new_pte, pte);
|
set_pte(new_pte, pte);
|
return;
|
return;
|
}
|
}
|
if (cow)
|
if (cow)
|
pte = pte_wrprotect(pte);
|
pte = pte_wrprotect(pte);
|
if (delete_from_swap_cache(page_nr))
|
if (delete_from_swap_cache(page_nr))
|
pte = pte_mkdirty(pte);
|
pte = pte_mkdirty(pte);
|
set_pte(new_pte, pte_mkold(pte));
|
set_pte(new_pte, pte_mkold(pte));
|
set_pte(old_pte, pte);
|
set_pte(old_pte, pte);
|
mem_map[page_nr].count++;
|
mem_map[page_nr].count++;
|
}
|
}
|
|
|
static inline int copy_pte_range(pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long address, unsigned long size, int cow)
|
static inline int copy_pte_range(pmd_t *dst_pmd, pmd_t *src_pmd, unsigned long address, unsigned long size, int cow)
|
{
|
{
|
pte_t * src_pte, * dst_pte;
|
pte_t * src_pte, * dst_pte;
|
unsigned long end;
|
unsigned long end;
|
|
|
if (pmd_none(*src_pmd))
|
if (pmd_none(*src_pmd))
|
return 0;
|
return 0;
|
if (pmd_bad(*src_pmd)) {
|
if (pmd_bad(*src_pmd)) {
|
printk("copy_pte_range: bad pmd (%08lx)\n", pmd_val(*src_pmd));
|
printk("copy_pte_range: bad pmd (%08lx)\n", pmd_val(*src_pmd));
|
pmd_clear(src_pmd);
|
pmd_clear(src_pmd);
|
return 0;
|
return 0;
|
}
|
}
|
src_pte = pte_offset(src_pmd, address);
|
src_pte = pte_offset(src_pmd, address);
|
if (pmd_none(*dst_pmd)) {
|
if (pmd_none(*dst_pmd)) {
|
if (!pte_alloc(dst_pmd, 0))
|
if (!pte_alloc(dst_pmd, 0))
|
return -ENOMEM;
|
return -ENOMEM;
|
}
|
}
|
dst_pte = pte_offset(dst_pmd, address);
|
dst_pte = pte_offset(dst_pmd, address);
|
address &= ~PMD_MASK;
|
address &= ~PMD_MASK;
|
end = address + size;
|
end = address + size;
|
if (end >= PMD_SIZE)
|
if (end >= PMD_SIZE)
|
end = PMD_SIZE;
|
end = PMD_SIZE;
|
do {
|
do {
|
/* I would like to switch arguments here, to make it
|
/* I would like to switch arguments here, to make it
|
* consistent with copy_xxx_range and memcpy syntax.
|
* consistent with copy_xxx_range and memcpy syntax.
|
*/
|
*/
|
copy_one_pte(src_pte++, dst_pte++, cow);
|
copy_one_pte(src_pte++, dst_pte++, cow);
|
address += PAGE_SIZE;
|
address += PAGE_SIZE;
|
} while (address < end);
|
} while (address < end);
|
return 0;
|
return 0;
|
}
|
}
|
|
|
static inline int copy_pmd_range(pgd_t *dst_pgd, pgd_t *src_pgd, unsigned long address, unsigned long size, int cow)
|
static inline int copy_pmd_range(pgd_t *dst_pgd, pgd_t *src_pgd, unsigned long address, unsigned long size, int cow)
|
{
|
{
|
pmd_t * src_pmd, * dst_pmd;
|
pmd_t * src_pmd, * dst_pmd;
|
unsigned long end;
|
unsigned long end;
|
int error = 0;
|
int error = 0;
|
|
|
if (pgd_none(*src_pgd))
|
if (pgd_none(*src_pgd))
|
return 0;
|
return 0;
|
if (pgd_bad(*src_pgd)) {
|
if (pgd_bad(*src_pgd)) {
|
printk("copy_pmd_range: bad pgd (%08lx)\n", pgd_val(*src_pgd));
|
printk("copy_pmd_range: bad pgd (%08lx)\n", pgd_val(*src_pgd));
|
pgd_clear(src_pgd);
|
pgd_clear(src_pgd);
|
return 0;
|
return 0;
|
}
|
}
|
src_pmd = pmd_offset(src_pgd, address);
|
src_pmd = pmd_offset(src_pgd, address);
|
if (pgd_none(*dst_pgd)) {
|
if (pgd_none(*dst_pgd)) {
|
if (!pmd_alloc(dst_pgd, 0))
|
if (!pmd_alloc(dst_pgd, 0))
|
return -ENOMEM;
|
return -ENOMEM;
|
}
|
}
|
dst_pmd = pmd_offset(dst_pgd, address);
|
dst_pmd = pmd_offset(dst_pgd, address);
|
address &= ~PGDIR_MASK;
|
address &= ~PGDIR_MASK;
|
end = address + size;
|
end = address + size;
|
if (end > PGDIR_SIZE)
|
if (end > PGDIR_SIZE)
|
end = PGDIR_SIZE;
|
end = PGDIR_SIZE;
|
do {
|
do {
|
error = copy_pte_range(dst_pmd++, src_pmd++, address, end - address, cow);
|
error = copy_pte_range(dst_pmd++, src_pmd++, address, end - address, cow);
|
if (error)
|
if (error)
|
break;
|
break;
|
address = (address + PMD_SIZE) & PMD_MASK;
|
address = (address + PMD_SIZE) & PMD_MASK;
|
} while (address < end);
|
} while (address < end);
|
return error;
|
return error;
|
}
|
}
|
|
|
/*
|
/*
|
* copy one vm_area from one task to the other. Assumes the page tables
|
* copy one vm_area from one task to the other. Assumes the page tables
|
* already present in the new task to be cleared in the whole range
|
* already present in the new task to be cleared in the whole range
|
* covered by this vma.
|
* covered by this vma.
|
*/
|
*/
|
int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
|
int copy_page_range(struct mm_struct *dst, struct mm_struct *src,
|
struct vm_area_struct *vma)
|
struct vm_area_struct *vma)
|
{
|
{
|
pgd_t * src_pgd, * dst_pgd;
|
pgd_t * src_pgd, * dst_pgd;
|
unsigned long address = vma->vm_start;
|
unsigned long address = vma->vm_start;
|
unsigned long end = vma->vm_end;
|
unsigned long end = vma->vm_end;
|
int error = 0, cow;
|
int error = 0, cow;
|
|
|
cow = (vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE;
|
cow = (vma->vm_flags & (VM_SHARED | VM_WRITE)) == VM_WRITE;
|
src_pgd = pgd_offset(src, address);
|
src_pgd = pgd_offset(src, address);
|
dst_pgd = pgd_offset(dst, address);
|
dst_pgd = pgd_offset(dst, address);
|
flush_cache_range(src, vma->vm_start, vma->vm_end);
|
flush_cache_range(src, vma->vm_start, vma->vm_end);
|
flush_cache_range(dst, vma->vm_start, vma->vm_end);
|
flush_cache_range(dst, vma->vm_start, vma->vm_end);
|
while (address < end) {
|
while (address < end) {
|
error = copy_pmd_range(dst_pgd++, src_pgd++, address, end - address, cow);
|
error = copy_pmd_range(dst_pgd++, src_pgd++, address, end - address, cow);
|
if (error)
|
if (error)
|
break;
|
break;
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
}
|
}
|
/* Note that the src ptes get c-o-w treatment, so they change too. */
|
/* Note that the src ptes get c-o-w treatment, so they change too. */
|
flush_tlb_range(src, vma->vm_start, vma->vm_end);
|
flush_tlb_range(src, vma->vm_start, vma->vm_end);
|
flush_tlb_range(dst, vma->vm_start, vma->vm_end);
|
flush_tlb_range(dst, vma->vm_start, vma->vm_end);
|
return error;
|
return error;
|
}
|
}
|
|
|
static inline void free_pte(pte_t page)
|
static inline void free_pte(pte_t page)
|
{
|
{
|
if (pte_present(page)) {
|
if (pte_present(page)) {
|
unsigned long addr = pte_page(page);
|
unsigned long addr = pte_page(page);
|
if (addr >= high_memory || PageReserved(mem_map+MAP_NR(addr)))
|
if (addr >= high_memory || PageReserved(mem_map+MAP_NR(addr)))
|
return;
|
return;
|
free_page(addr);
|
free_page(addr);
|
if (current->mm->rss <= 0)
|
if (current->mm->rss <= 0)
|
return;
|
return;
|
current->mm->rss--;
|
current->mm->rss--;
|
return;
|
return;
|
}
|
}
|
swap_free(pte_val(page));
|
swap_free(pte_val(page));
|
}
|
}
|
|
|
static inline void forget_pte(pte_t page)
|
static inline void forget_pte(pte_t page)
|
{
|
{
|
if (!pte_none(page)) {
|
if (!pte_none(page)) {
|
printk("forget_pte: old mapping existed!\n");
|
printk("forget_pte: old mapping existed!\n");
|
free_pte(page);
|
free_pte(page);
|
}
|
}
|
}
|
}
|
|
|
static inline void zap_pte_range(pmd_t * pmd, unsigned long address, unsigned long size)
|
static inline void zap_pte_range(pmd_t * pmd, unsigned long address, unsigned long size)
|
{
|
{
|
pte_t * pte;
|
pte_t * pte;
|
|
|
if (pmd_none(*pmd))
|
if (pmd_none(*pmd))
|
return;
|
return;
|
if (pmd_bad(*pmd)) {
|
if (pmd_bad(*pmd)) {
|
printk("zap_pte_range: bad pmd (%08lx)\n", pmd_val(*pmd));
|
printk("zap_pte_range: bad pmd (%08lx)\n", pmd_val(*pmd));
|
pmd_clear(pmd);
|
pmd_clear(pmd);
|
return;
|
return;
|
}
|
}
|
pte = pte_offset(pmd, address);
|
pte = pte_offset(pmd, address);
|
address &= ~PMD_MASK;
|
address &= ~PMD_MASK;
|
if (address + size > PMD_SIZE)
|
if (address + size > PMD_SIZE)
|
size = PMD_SIZE - address;
|
size = PMD_SIZE - address;
|
size >>= PAGE_SHIFT;
|
size >>= PAGE_SHIFT;
|
for (;;) {
|
for (;;) {
|
pte_t page;
|
pte_t page;
|
if (!size)
|
if (!size)
|
break;
|
break;
|
page = *pte;
|
page = *pte;
|
pte++;
|
pte++;
|
size--;
|
size--;
|
if (pte_none(page))
|
if (pte_none(page))
|
continue;
|
continue;
|
pte_clear(pte-1);
|
pte_clear(pte-1);
|
free_pte(page);
|
free_pte(page);
|
}
|
}
|
}
|
}
|
|
|
static inline void zap_pmd_range(pgd_t * dir, unsigned long address, unsigned long size)
|
static inline void zap_pmd_range(pgd_t * dir, unsigned long address, unsigned long size)
|
{
|
{
|
pmd_t * pmd;
|
pmd_t * pmd;
|
unsigned long end;
|
unsigned long end;
|
|
|
if (pgd_none(*dir))
|
if (pgd_none(*dir))
|
return;
|
return;
|
if (pgd_bad(*dir)) {
|
if (pgd_bad(*dir)) {
|
printk("zap_pmd_range: bad pgd (%08lx)\n", pgd_val(*dir));
|
printk("zap_pmd_range: bad pgd (%08lx)\n", pgd_val(*dir));
|
pgd_clear(dir);
|
pgd_clear(dir);
|
return;
|
return;
|
}
|
}
|
pmd = pmd_offset(dir, address);
|
pmd = pmd_offset(dir, address);
|
address &= ~PGDIR_MASK;
|
address &= ~PGDIR_MASK;
|
end = address + size;
|
end = address + size;
|
if (end > PGDIR_SIZE)
|
if (end > PGDIR_SIZE)
|
end = PGDIR_SIZE;
|
end = PGDIR_SIZE;
|
do {
|
do {
|
zap_pte_range(pmd, address, end - address);
|
zap_pte_range(pmd, address, end - address);
|
address = (address + PMD_SIZE) & PMD_MASK;
|
address = (address + PMD_SIZE) & PMD_MASK;
|
pmd++;
|
pmd++;
|
} while (address < end);
|
} while (address < end);
|
}
|
}
|
|
|
/*
|
/*
|
* remove user pages in a given range.
|
* remove user pages in a given range.
|
*/
|
*/
|
int zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size)
|
int zap_page_range(struct mm_struct *mm, unsigned long address, unsigned long size)
|
{
|
{
|
pgd_t * dir;
|
pgd_t * dir;
|
unsigned long end = address + size;
|
unsigned long end = address + size;
|
|
|
dir = pgd_offset(mm, address);
|
dir = pgd_offset(mm, address);
|
flush_cache_range(mm, end - size, end);
|
flush_cache_range(mm, end - size, end);
|
while (address < end) {
|
while (address < end) {
|
zap_pmd_range(dir, address, end - address);
|
zap_pmd_range(dir, address, end - address);
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
dir++;
|
dir++;
|
}
|
}
|
flush_tlb_range(mm, end - size, end);
|
flush_tlb_range(mm, end - size, end);
|
return 0;
|
return 0;
|
}
|
}
|
|
|
static inline void zeromap_pte_range(pte_t * pte, unsigned long address, unsigned long size, pte_t zero_pte)
|
static inline void zeromap_pte_range(pte_t * pte, unsigned long address, unsigned long size, pte_t zero_pte)
|
{
|
{
|
unsigned long end;
|
unsigned long end;
|
|
|
address &= ~PMD_MASK;
|
address &= ~PMD_MASK;
|
end = address + size;
|
end = address + size;
|
if (end > PMD_SIZE)
|
if (end > PMD_SIZE)
|
end = PMD_SIZE;
|
end = PMD_SIZE;
|
do {
|
do {
|
pte_t oldpage = *pte;
|
pte_t oldpage = *pte;
|
set_pte(pte, zero_pte);
|
set_pte(pte, zero_pte);
|
forget_pte(oldpage);
|
forget_pte(oldpage);
|
address += PAGE_SIZE;
|
address += PAGE_SIZE;
|
pte++;
|
pte++;
|
} while (address < end);
|
} while (address < end);
|
}
|
}
|
|
|
static inline int zeromap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size, pte_t zero_pte)
|
static inline int zeromap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size, pte_t zero_pte)
|
{
|
{
|
unsigned long end;
|
unsigned long end;
|
|
|
address &= ~PGDIR_MASK;
|
address &= ~PGDIR_MASK;
|
end = address + size;
|
end = address + size;
|
if (end > PGDIR_SIZE)
|
if (end > PGDIR_SIZE)
|
end = PGDIR_SIZE;
|
end = PGDIR_SIZE;
|
do {
|
do {
|
pte_t * pte = pte_alloc(pmd, address);
|
pte_t * pte = pte_alloc(pmd, address);
|
if (!pte)
|
if (!pte)
|
return -ENOMEM;
|
return -ENOMEM;
|
zeromap_pte_range(pte, address, end - address, zero_pte);
|
zeromap_pte_range(pte, address, end - address, zero_pte);
|
address = (address + PMD_SIZE) & PMD_MASK;
|
address = (address + PMD_SIZE) & PMD_MASK;
|
pmd++;
|
pmd++;
|
} while (address < end);
|
} while (address < end);
|
return 0;
|
return 0;
|
}
|
}
|
|
|
int zeromap_page_range(unsigned long address, unsigned long size, pgprot_t prot)
|
int zeromap_page_range(unsigned long address, unsigned long size, pgprot_t prot)
|
{
|
{
|
int error = 0;
|
int error = 0;
|
pgd_t * dir;
|
pgd_t * dir;
|
unsigned long beg = address;
|
unsigned long beg = address;
|
unsigned long end = address + size;
|
unsigned long end = address + size;
|
pte_t zero_pte;
|
pte_t zero_pte;
|
|
|
zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE, prot));
|
zero_pte = pte_wrprotect(mk_pte(ZERO_PAGE, prot));
|
dir = pgd_offset(current->mm, address);
|
dir = pgd_offset(current->mm, address);
|
flush_cache_range(current->mm, beg, end);
|
flush_cache_range(current->mm, beg, end);
|
while (address < end) {
|
while (address < end) {
|
pmd_t *pmd = pmd_alloc(dir, address);
|
pmd_t *pmd = pmd_alloc(dir, address);
|
error = -ENOMEM;
|
error = -ENOMEM;
|
if (!pmd)
|
if (!pmd)
|
break;
|
break;
|
error = zeromap_pmd_range(pmd, address, end - address, zero_pte);
|
error = zeromap_pmd_range(pmd, address, end - address, zero_pte);
|
if (error)
|
if (error)
|
break;
|
break;
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
address = (address + PGDIR_SIZE) & PGDIR_MASK;
|
dir++;
|
dir++;
|
}
|
}
|
flush_tlb_range(current->mm, beg, end);
|
flush_tlb_range(current->mm, beg, end);
|
return error;
|
return error;
|
}
|
}
|
|
|
/*
|
/*
|
* maps a range of physical memory into the requested pages. the old
|
* maps a range of physical memory into the requested pages. the old
|
* mappings are removed. any references to nonexistent pages results
|
* mappings are removed. any references to nonexistent pages results
|
* in null mappings (currently treated as "copy-on-access")
|
* in null mappings (currently treated as "copy-on-access")
|
*/
|
*/
|
static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
|
static inline void remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
|
unsigned long offset, pgprot_t prot)
|
unsigned long offset, pgprot_t prot)
|
{
|
{
|
unsigned long end;
|
unsigned long end;
|
|
|
address &= ~PMD_MASK;
|
address &= ~PMD_MASK;
|
end = address + size;
|
end = address + size;
|
if (end > PMD_SIZE)
|
if (end > PMD_SIZE)
|
end = PMD_SIZE;
|
end = PMD_SIZE;
|
do {
|
do {
|
pte_t oldpage = *pte;
|
pte_t oldpage = *pte;
|
pte_clear(pte);
|
pte_clear(pte);
|
if (offset >= high_memory || PageReserved(mem_map+MAP_NR(offset)))
|
if (offset >= high_memory || PageReserved(mem_map+MAP_NR(offset)))
|
set_pte(pte, mk_pte(offset, prot));
|
set_pte(pte, mk_pte(offset, prot));
|
forget_pte(oldpage);
|
forget_pte(oldpage);
|
address += PAGE_SIZE;
|
address += PAGE_SIZE;
|
offset += PAGE_SIZE;
|
offset += PAGE_SIZE;
|
pte++;
|
pte++;
|
} while (address < end);
|
} while (address < end);
|
}
|
}
|
|
|
static inline int remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
|
static inline int remap_pmd_range(pmd_t * pmd, unsigned long address, unsigned long size,
|
unsigned long offset, pgprot_t prot)
|
unsigned long offset, pgprot_t prot)
|
{
|
{
|
unsigned long end;
|
unsigned long end;
|
|
|
address &= ~PGDIR_MASK;
|
address &= ~PGDIR_MASK;
|
end = address + size;
|
end = address + size;
|
if (end > PGDIR_SIZE)
|
if (end > PGDIR_SIZE)
|
end = PGDIR_SIZE;
|
end = PGDIR_SIZE;
|
offset -= address;
|
offset -= address;
|
do {
|
do {
|
pte_t * pte = pte_alloc(pmd, address);
|
pte_t * pte = pte_alloc(pmd, address);
|
if (!pte)
|
if (!pte)
|
return -ENOMEM;
|
return -ENOMEM;
|
remap_pte_range(pte, address, end - address, address + offset, prot);
|
remap_pte_range(pte, address, end - address, address + offset, prot);
|
address = (address + PMD_SIZE) & PMD_MASK;
|
address = (address + PMD_SIZE) & PMD_MASK;
|
pmd++;
|
pmd++;
|
} while (address < end);
|
} while (address < end);
|
return 0;
|
return 0;
|
}
|
}
|
|
|
int remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot)
|
int remap_page_range(unsigned long from, unsigned long offset, unsigned long size, pgprot_t prot)
|
{
|
{
|
int error = 0;
|
int error = 0;
|
pgd_t * dir;
|
pgd_t * dir;
|
unsigned long beg = from;
|
unsigned long beg = from;
|
unsigned long end = from + size;
|
unsigned long end = from + size;
|
|
|
offset -= from;
|
offset -= from;
|
dir = pgd_offset(current->mm, from);
|
dir = pgd_offset(current->mm, from);
|
flush_cache_range(current->mm, beg, end);
|
flush_cache_range(current->mm, beg, end);
|
while (from < end) {
|
while (from < end) {
|
pmd_t *pmd = pmd_alloc(dir, from);
|
pmd_t *pmd = pmd_alloc(dir, from);
|
error = -ENOMEM;
|
error = -ENOMEM;
|
if (!pmd)
|
if (!pmd)
|
break;
|
break;
|
error = remap_pmd_range(pmd, from, end - from, offset + from, prot);
|
error = remap_pmd_range(pmd, from, end - from, offset + from, prot);
|
if (error)
|
if (error)
|
break;
|
break;
|
from = (from + PGDIR_SIZE) & PGDIR_MASK;
|
from = (from + PGDIR_SIZE) & PGDIR_MASK;
|
dir++;
|
dir++;
|
}
|
}
|
flush_tlb_range(current->mm, beg, end);
|
flush_tlb_range(current->mm, beg, end);
|
return error;
|
return error;
|
}
|
}
|
|
|
/*
|
/*
|
* sanity-check function..
|
* sanity-check function..
|
*/
|
*/
|
static void put_page(pte_t * page_table, pte_t pte)
|
static void put_page(pte_t * page_table, pte_t pte)
|
{
|
{
|
if (!pte_none(*page_table)) {
|
if (!pte_none(*page_table)) {
|
free_page(pte_page(pte));
|
free_page(pte_page(pte));
|
return;
|
return;
|
}
|
}
|
/* no need for flush_tlb */
|
/* no need for flush_tlb */
|
set_pte(page_table, pte);
|
set_pte(page_table, pte);
|
}
|
}
|
|
|
/*
|
/*
|
* This routine is used to map in a page into an address space: needed by
|
* This routine is used to map in a page into an address space: needed by
|
* execve() for the initial stack and environment pages.
|
* execve() for the initial stack and environment pages.
|
*/
|
*/
|
unsigned long put_dirty_page(struct task_struct * tsk, unsigned long page, unsigned long address)
|
unsigned long put_dirty_page(struct task_struct * tsk, unsigned long page, unsigned long address)
|
{
|
{
|
pgd_t * pgd;
|
pgd_t * pgd;
|
pmd_t * pmd;
|
pmd_t * pmd;
|
pte_t * pte;
|
pte_t * pte;
|
|
|
if (page >= high_memory)
|
if (page >= high_memory)
|
printk("put_dirty_page: trying to put page %08lx at %08lx\n",page,address);
|
printk("put_dirty_page: trying to put page %08lx at %08lx\n",page,address);
|
if (mem_map[MAP_NR(page)].count != 1)
|
if (mem_map[MAP_NR(page)].count != 1)
|
printk("mem_map disagrees with %08lx at %08lx\n",page,address);
|
printk("mem_map disagrees with %08lx at %08lx\n",page,address);
|
pgd = pgd_offset(tsk->mm,address);
|
pgd = pgd_offset(tsk->mm,address);
|
pmd = pmd_alloc(pgd, address);
|
pmd = pmd_alloc(pgd, address);
|
if (!pmd) {
|
if (!pmd) {
|
free_page(page);
|
free_page(page);
|
oom(tsk);
|
oom(tsk);
|
return 0;
|
return 0;
|
}
|
}
|
pte = pte_alloc(pmd, address);
|
pte = pte_alloc(pmd, address);
|
if (!pte) {
|
if (!pte) {
|
free_page(page);
|
free_page(page);
|
oom(tsk);
|
oom(tsk);
|
return 0;
|
return 0;
|
}
|
}
|
if (!pte_none(*pte)) {
|
if (!pte_none(*pte)) {
|
printk("put_dirty_page: page already exists\n");
|
printk("put_dirty_page: page already exists\n");
|
free_page(page);
|
free_page(page);
|
return 0;
|
return 0;
|
}
|
}
|
flush_page_to_ram(page);
|
flush_page_to_ram(page);
|
set_pte(pte, pte_mkwrite(pte_mkdirty(mk_pte(page, PAGE_COPY))));
|
set_pte(pte, pte_mkwrite(pte_mkdirty(mk_pte(page, PAGE_COPY))));
|
/* no need for invalidate */
|
/* no need for invalidate */
|
return page;
|
return page;
|
}
|
}
|
|
|
/*
|
/*
|
* This routine handles present pages, when users try to write
|
* This routine handles present pages, when users try to write
|
* to a shared page. It is done by copying the page to a new address
|
* to a shared page. It is done by copying the page to a new address
|
* and decrementing the shared-page counter for the old page.
|
* and decrementing the shared-page counter for the old page.
|
*
|
*
|
* Goto-purists beware: the only reason for goto's here is that it results
|
* Goto-purists beware: the only reason for goto's here is that it results
|
* in better assembly code.. The "default" path will see no jumps at all.
|
* in better assembly code.. The "default" path will see no jumps at all.
|
*
|
*
|
* Note that this routine assumes that the protection checks have been
|
* Note that this routine assumes that the protection checks have been
|
* done by the caller (the low-level page fault routine in most cases).
|
* done by the caller (the low-level page fault routine in most cases).
|
* Thus we can safely just mark it writable once we've done any necessary
|
* Thus we can safely just mark it writable once we've done any necessary
|
* COW.
|
* COW.
|
*
|
*
|
* We also mark the page dirty at this point even though the page will
|
* We also mark the page dirty at this point even though the page will
|
* change only once the write actually happens. This avoids a few races,
|
* change only once the write actually happens. This avoids a few races,
|
* and potentially makes it more efficient.
|
* and potentially makes it more efficient.
|
*/
|
*/
|
void do_wp_page(struct task_struct * tsk, struct vm_area_struct * vma,
|
void do_wp_page(struct task_struct * tsk, struct vm_area_struct * vma,
|
unsigned long address, int write_access)
|
unsigned long address, int write_access)
|
{
|
{
|
pgd_t *page_dir;
|
pgd_t *page_dir;
|
pmd_t *page_middle;
|
pmd_t *page_middle;
|
pte_t *page_table, pte;
|
pte_t *page_table, pte;
|
unsigned long old_page, new_page;
|
unsigned long old_page, new_page;
|
|
|
new_page = __get_free_page(GFP_KERNEL);
|
new_page = __get_free_page(GFP_KERNEL);
|
page_dir = pgd_offset(vma->vm_mm, address);
|
page_dir = pgd_offset(vma->vm_mm, address);
|
if (pgd_none(*page_dir))
|
if (pgd_none(*page_dir))
|
goto end_wp_page;
|
goto end_wp_page;
|
if (pgd_bad(*page_dir))
|
if (pgd_bad(*page_dir))
|
goto bad_wp_pagedir;
|
goto bad_wp_pagedir;
|
page_middle = pmd_offset(page_dir, address);
|
page_middle = pmd_offset(page_dir, address);
|
if (pmd_none(*page_middle))
|
if (pmd_none(*page_middle))
|
goto end_wp_page;
|
goto end_wp_page;
|
if (pmd_bad(*page_middle))
|
if (pmd_bad(*page_middle))
|
goto bad_wp_pagemiddle;
|
goto bad_wp_pagemiddle;
|
page_table = pte_offset(page_middle, address);
|
page_table = pte_offset(page_middle, address);
|
pte = *page_table;
|
pte = *page_table;
|
if (!pte_present(pte))
|
if (!pte_present(pte))
|
goto end_wp_page;
|
goto end_wp_page;
|
if (pte_write(pte))
|
if (pte_write(pte))
|
goto end_wp_page;
|
goto end_wp_page;
|
old_page = pte_page(pte);
|
old_page = pte_page(pte);
|
if (old_page >= high_memory)
|
if (old_page >= high_memory)
|
goto bad_wp_page;
|
goto bad_wp_page;
|
tsk->min_flt++;
|
tsk->min_flt++;
|
/*
|
/*
|
* Do we need to copy?
|
* Do we need to copy?
|
*/
|
*/
|
if (mem_map[MAP_NR(old_page)].count != 1) {
|
if (mem_map[MAP_NR(old_page)].count != 1) {
|
if (new_page) {
|
if (new_page) {
|
if (PageReserved(mem_map + MAP_NR(old_page)))
|
if (PageReserved(mem_map + MAP_NR(old_page)))
|
++vma->vm_mm->rss;
|
++vma->vm_mm->rss;
|
copy_page(old_page,new_page);
|
copy_page(old_page,new_page);
|
flush_page_to_ram(old_page);
|
flush_page_to_ram(old_page);
|
flush_page_to_ram(new_page);
|
flush_page_to_ram(new_page);
|
flush_cache_page(vma, address);
|
flush_cache_page(vma, address);
|
set_pte(page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot))));
|
set_pte(page_table, pte_mkwrite(pte_mkdirty(mk_pte(new_page, vma->vm_page_prot))));
|
free_page(old_page);
|
free_page(old_page);
|
flush_tlb_page(vma, address);
|
flush_tlb_page(vma, address);
|
return;
|
return;
|
}
|
}
|
flush_cache_page(vma, address);
|
flush_cache_page(vma, address);
|
set_pte(page_table, BAD_PAGE);
|
set_pte(page_table, BAD_PAGE);
|
flush_tlb_page(vma, address);
|
flush_tlb_page(vma, address);
|
free_page(old_page);
|
free_page(old_page);
|
oom(tsk);
|
oom(tsk);
|
return;
|
return;
|
}
|
}
|
flush_cache_page(vma, address);
|
flush_cache_page(vma, address);
|
set_pte(page_table, pte_mkdirty(pte_mkwrite(pte)));
|
set_pte(page_table, pte_mkdirty(pte_mkwrite(pte)));
|
flush_tlb_page(vma, address);
|
flush_tlb_page(vma, address);
|
if (new_page)
|
if (new_page)
|
free_page(new_page);
|
free_page(new_page);
|
return;
|
return;
|
bad_wp_page:
|
bad_wp_page:
|
printk("do_wp_page: bogus page at address %08lx (%08lx)\n",address,old_page);
|
printk("do_wp_page: bogus page at address %08lx (%08lx)\n",address,old_page);
|
send_sig(SIGKILL, tsk, 1);
|
send_sig(SIGKILL, tsk, 1);
|
goto end_wp_page;
|
goto end_wp_page;
|
bad_wp_pagemiddle:
|
bad_wp_pagemiddle:
|
printk("do_wp_page: bogus page-middle at address %08lx (%08lx)\n", address, pmd_val(*page_middle));
|
printk("do_wp_page: bogus page-middle at address %08lx (%08lx)\n", address, pmd_val(*page_middle));
|
send_sig(SIGKILL, tsk, 1);
|
send_sig(SIGKILL, tsk, 1);
|
goto end_wp_page;
|
goto end_wp_page;
|
bad_wp_pagedir:
|
bad_wp_pagedir:
|
printk("do_wp_page: bogus page-dir entry at address %08lx (%08lx)\n", address, pgd_val(*page_dir));
|
printk("do_wp_page: bogus page-dir entry at address %08lx (%08lx)\n", address, pgd_val(*page_dir));
|
send_sig(SIGKILL, tsk, 1);
|
send_sig(SIGKILL, tsk, 1);
|
end_wp_page:
|
end_wp_page:
|
if (new_page)
|
if (new_page)
|
free_page(new_page);
|
free_page(new_page);
|
return;
|
return;
|
}
|
}
|
|
|
/*
|
/*
|
* Ugly, ugly, but the goto's result in better assembly..
|
* Ugly, ugly, but the goto's result in better assembly..
|
*/
|
*/
|
int verify_area(int type, const void * addr, unsigned long size)
|
int verify_area(int type, const void * addr, unsigned long size)
|
{
|
{
|
struct vm_area_struct * vma;
|
struct vm_area_struct * vma;
|
unsigned long start = (unsigned long) addr;
|
unsigned long start = (unsigned long) addr;
|
|
|
/* If the current user space is mapped to kernel space (for the
|
/* If the current user space is mapped to kernel space (for the
|
* case where we use a fake user buffer with get_fs/set_fs()) we
|
* case where we use a fake user buffer with get_fs/set_fs()) we
|
* don't expect to find the address in the user vm map.
|
* don't expect to find the address in the user vm map.
|
*/
|
*/
|
if (!size || get_fs() == KERNEL_DS)
|
if (!size || get_fs() == KERNEL_DS)
|
return 0;
|
return 0;
|
|
|
vma = find_vma(current->mm, start);
|
vma = find_vma(current->mm, start);
|
if (!vma)
|
if (!vma)
|
goto bad_area;
|
goto bad_area;
|
if (vma->vm_start > start)
|
if (vma->vm_start > start)
|
goto check_stack;
|
goto check_stack;
|
|
|
good_area:
|
good_area:
|
if (type == VERIFY_WRITE)
|
if (type == VERIFY_WRITE)
|
goto check_write;
|
goto check_write;
|
for (;;) {
|
for (;;) {
|
struct vm_area_struct * next;
|
struct vm_area_struct * next;
|
if (!(vma->vm_flags & VM_READ))
|
if (!(vma->vm_flags & VM_READ))
|
goto bad_area;
|
goto bad_area;
|
if (vma->vm_end - start >= size)
|
if (vma->vm_end - start >= size)
|
return 0;
|
return 0;
|
next = vma->vm_next;
|
next = vma->vm_next;
|
if (!next || vma->vm_end != next->vm_start)
|
if (!next || vma->vm_end != next->vm_start)
|
goto bad_area;
|
goto bad_area;
|
vma = next;
|
vma = next;
|
}
|
}
|
|
|
check_write:
|
check_write:
|
if (!(vma->vm_flags & VM_WRITE))
|
if (!(vma->vm_flags & VM_WRITE))
|
goto bad_area;
|
goto bad_area;
|
if (!wp_works_ok)
|
if (!wp_works_ok)
|
goto check_wp_fault_by_hand;
|
goto check_wp_fault_by_hand;
|
for (;;) {
|
for (;;) {
|
if (vma->vm_end - start >= size)
|
if (vma->vm_end - start >= size)
|
break;
|
break;
|
if (!vma->vm_next || vma->vm_end != vma->vm_next->vm_start)
|
if (!vma->vm_next || vma->vm_end != vma->vm_next->vm_start)
|
goto bad_area;
|
goto bad_area;
|
vma = vma->vm_next;
|
vma = vma->vm_next;
|
if (!(vma->vm_flags & VM_WRITE))
|
if (!(vma->vm_flags & VM_WRITE))
|
goto bad_area;
|
goto bad_area;
|
}
|
}
|
return 0;
|
return 0;
|
|
|
check_wp_fault_by_hand:
|
check_wp_fault_by_hand:
|
size--;
|
size--;
|
size += start & ~PAGE_MASK;
|
size += start & ~PAGE_MASK;
|
size >>= PAGE_SHIFT;
|
size >>= PAGE_SHIFT;
|
start &= PAGE_MASK;
|
start &= PAGE_MASK;
|
|
|
for (;;) {
|
for (;;) {
|
do_wp_page(current, vma, start, 1);
|
do_wp_page(current, vma, start, 1);
|
if (!size)
|
if (!size)
|
break;
|
break;
|
size--;
|
size--;
|
start += PAGE_SIZE;
|
start += PAGE_SIZE;
|
if (start < vma->vm_end)
|
if (start < vma->vm_end)
|
continue;
|
continue;
|
vma = vma->vm_next;
|
vma = vma->vm_next;
|
if (!vma || vma->vm_start != start)
|
if (!vma || vma->vm_start != start)
|
goto bad_area;
|
goto bad_area;
|
if (!(vma->vm_flags & VM_WRITE))
|
if (!(vma->vm_flags & VM_WRITE))
|
goto bad_area;;
|
goto bad_area;;
|
}
|
}
|
return 0;
|
return 0;
|
|
|
check_stack:
|
check_stack:
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
if (!(vma->vm_flags & VM_GROWSDOWN))
|
goto bad_area;
|
goto bad_area;
|
if (expand_stack(vma, start) == 0)
|
if (expand_stack(vma, start) == 0)
|
goto good_area;
|
goto good_area;
|
|
|
bad_area:
|
bad_area:
|
return -EFAULT;
|
return -EFAULT;
|
}
|
}
|
|
|
/*
|
/*
|
* This function zeroes out partial mmap'ed pages at truncation time..
|
* This function zeroes out partial mmap'ed pages at truncation time..
|
*/
|
*/
|
static void partial_clear(struct vm_area_struct *vma, unsigned long address)
|
static void partial_clear(struct vm_area_struct *vma, unsigned long address)
|
{
|
{
|
pgd_t *page_dir;
|
pgd_t *page_dir;
|
pmd_t *page_middle;
|
pmd_t *page_middle;
|
pte_t *page_table, pte;
|
pte_t *page_table, pte;
|
|
|
page_dir = pgd_offset(vma->vm_mm, address);
|
page_dir = pgd_offset(vma->vm_mm, address);
|
if (pgd_none(*page_dir))
|
if (pgd_none(*page_dir))
|
return;
|
return;
|
if (pgd_bad(*page_dir)) {
|
if (pgd_bad(*page_dir)) {
|
printk("bad page table directory entry %p:[%lx]\n", page_dir, pgd_val(*page_dir));
|
printk("bad page table directory entry %p:[%lx]\n", page_dir, pgd_val(*page_dir));
|
pgd_clear(page_dir);
|
pgd_clear(page_dir);
|
return;
|
return;
|
}
|
}
|
page_middle = pmd_offset(page_dir, address);
|
page_middle = pmd_offset(page_dir, address);
|
if (pmd_none(*page_middle))
|
if (pmd_none(*page_middle))
|
return;
|
return;
|
if (pmd_bad(*page_middle)) {
|
if (pmd_bad(*page_middle)) {
|
printk("bad page table directory entry %p:[%lx]\n", page_dir, pgd_val(*page_dir));
|
printk("bad page table directory entry %p:[%lx]\n", page_dir, pgd_val(*page_dir));
|
pmd_clear(page_middle);
|
pmd_clear(page_middle);
|
return;
|
return;
|
}
|
}
|
page_table = pte_offset(page_middle, address);
|
page_table = pte_offset(page_middle, address);
|
pte = *page_table;
|
pte = *page_table;
|
if (!pte_present(pte))
|
if (!pte_present(pte))
|
return;
|
return;
|
flush_cache_page(vma, address);
|
flush_cache_page(vma, address);
|
address &= ~PAGE_MASK;
|
address &= ~PAGE_MASK;
|
address += pte_page(pte);
|
address += pte_page(pte);
|
if (address >= high_memory)
|
if (address >= high_memory)
|
return;
|
return;
|
memset((void *) address, 0, PAGE_SIZE - (address & ~PAGE_MASK));
|
memset((void *) address, 0, PAGE_SIZE - (address & ~PAGE_MASK));
|
flush_page_to_ram(pte_page(pte));
|
flush_page_to_ram(pte_page(pte));
|
}
|
}
|
|
|
/*
|
/*
|
* Handle all mappings that got truncated by a "truncate()"
|
* Handle all mappings that got truncated by a "truncate()"
|
* system call.
|
* system call.
|
*
|
*
|
* NOTE! We have to be ready to update the memory sharing
|
* NOTE! We have to be ready to update the memory sharing
|
* between the file and the memory map for a potential last
|
* between the file and the memory map for a potential last
|
* incomplete page. Ugly, but necessary.
|
* incomplete page. Ugly, but necessary.
|
*/
|
*/
|
void vmtruncate(struct inode * inode, unsigned long offset)
|
void vmtruncate(struct inode * inode, unsigned long offset)
|
{
|
{
|
struct vm_area_struct * mpnt;
|
struct vm_area_struct * mpnt;
|
|
|
truncate_inode_pages(inode, offset);
|
truncate_inode_pages(inode, offset);
|
if (!inode->i_mmap)
|
if (!inode->i_mmap)
|
return;
|
return;
|
mpnt = inode->i_mmap;
|
mpnt = inode->i_mmap;
|
do {
|
do {
|
unsigned long start = mpnt->vm_start;
|
unsigned long start = mpnt->vm_start;
|
unsigned long len = mpnt->vm_end - start;
|
unsigned long len = mpnt->vm_end - start;
|
unsigned long diff;
|
unsigned long diff;
|
|
|
/* mapping wholly truncated? */
|
/* mapping wholly truncated? */
|
if (mpnt->vm_offset >= offset) {
|
if (mpnt->vm_offset >= offset) {
|
zap_page_range(mpnt->vm_mm, start, len);
|
zap_page_range(mpnt->vm_mm, start, len);
|
continue;
|
continue;
|
}
|
}
|
/* mapping wholly unaffected? */
|
/* mapping wholly unaffected? */
|
diff = offset - mpnt->vm_offset;
|
diff = offset - mpnt->vm_offset;
|
if (diff >= len)
|
if (diff >= len)
|
continue;
|
continue;
|
/* Ok, partially affected.. */
|
/* Ok, partially affected.. */
|
start += diff;
|
start += diff;
|
len = (len - diff) & PAGE_MASK;
|
len = (len - diff) & PAGE_MASK;
|
if (start & ~PAGE_MASK) {
|
if (start & ~PAGE_MASK) {
|
partial_clear(mpnt, start);
|
partial_clear(mpnt, start);
|
start = (start + ~PAGE_MASK) & PAGE_MASK;
|
start = (start + ~PAGE_MASK) & PAGE_MASK;
|
}
|
}
|
zap_page_range(mpnt->vm_mm, start, len);
|
zap_page_range(mpnt->vm_mm, start, len);
|
} while ((mpnt = mpnt->vm_next_share) != inode->i_mmap);
|
} while ((mpnt = mpnt->vm_next_share) != inode->i_mmap);
|
}
|
}
|
|
|
|
|
static inline void do_swap_page(struct task_struct * tsk,
|
static inline void do_swap_page(struct task_struct * tsk,
|
struct vm_area_struct * vma, unsigned long address,
|
struct vm_area_struct * vma, unsigned long address,
|
pte_t * page_table, pte_t entry, int write_access)
|
pte_t * page_table, pte_t entry, int write_access)
|
{
|
{
|
pte_t page;
|
pte_t page;
|
|
|
if (!vma->vm_ops || !vma->vm_ops->swapin) {
|
if (!vma->vm_ops || !vma->vm_ops->swapin) {
|
swap_in(tsk, vma, page_table, pte_val(entry), write_access);
|
swap_in(tsk, vma, page_table, pte_val(entry), write_access);
|
flush_page_to_ram(pte_page(*page_table));
|
flush_page_to_ram(pte_page(*page_table));
|
return;
|
return;
|
}
|
}
|
page = vma->vm_ops->swapin(vma, address - vma->vm_start + vma->vm_offset, pte_val(entry));
|
page = vma->vm_ops->swapin(vma, address - vma->vm_start + vma->vm_offset, pte_val(entry));
|
if (pte_val(*page_table) != pte_val(entry)) {
|
if (pte_val(*page_table) != pte_val(entry)) {
|
free_page(pte_page(page));
|
free_page(pte_page(page));
|
return;
|
return;
|
}
|
}
|
if (mem_map[MAP_NR(pte_page(page))].count > 1 && !(vma->vm_flags & VM_SHARED))
|
if (mem_map[MAP_NR(pte_page(page))].count > 1 && !(vma->vm_flags & VM_SHARED))
|
page = pte_wrprotect(page);
|
page = pte_wrprotect(page);
|
++vma->vm_mm->rss;
|
++vma->vm_mm->rss;
|
++tsk->maj_flt;
|
++tsk->maj_flt;
|
flush_page_to_ram(pte_page(page));
|
flush_page_to_ram(pte_page(page));
|
set_pte(page_table, page);
|
set_pte(page_table, page);
|
return;
|
return;
|
}
|
}
|
|
|
/*
|
/*
|
* do_no_page() tries to create a new page mapping. It aggressively
|
* do_no_page() tries to create a new page mapping. It aggressively
|
* tries to share with existing pages, but makes a separate copy if
|
* tries to share with existing pages, but makes a separate copy if
|
* the "write_access" parameter is true in order to avoid the next
|
* the "write_access" parameter is true in order to avoid the next
|
* page fault.
|
* page fault.
|
*
|
*
|
* As this is called only for pages that do not currently exist, we
|
* As this is called only for pages that do not currently exist, we
|
* do not need to flush old virtual caches or the TLB.
|
* do not need to flush old virtual caches or the TLB.
|
*/
|
*/
|
void do_no_page(struct task_struct * tsk, struct vm_area_struct * vma,
|
void do_no_page(struct task_struct * tsk, struct vm_area_struct * vma,
|
unsigned long address, int write_access)
|
unsigned long address, int write_access)
|
{
|
{
|
pgd_t * pgd;
|
pgd_t * pgd;
|
pmd_t * pmd;
|
pmd_t * pmd;
|
pte_t * page_table;
|
pte_t * page_table;
|
pte_t entry;
|
pte_t entry;
|
unsigned long page;
|
unsigned long page;
|
|
|
pgd = pgd_offset(tsk->mm, address);
|
pgd = pgd_offset(tsk->mm, address);
|
pmd = pmd_alloc(pgd, address);
|
pmd = pmd_alloc(pgd, address);
|
if (!pmd)
|
if (!pmd)
|
goto no_memory;
|
goto no_memory;
|
page_table = pte_alloc(pmd, address);
|
page_table = pte_alloc(pmd, address);
|
if (!page_table)
|
if (!page_table)
|
goto no_memory;
|
goto no_memory;
|
entry = *page_table;
|
entry = *page_table;
|
if (pte_present(entry))
|
if (pte_present(entry))
|
goto is_present;
|
goto is_present;
|
if (!pte_none(entry))
|
if (!pte_none(entry))
|
goto swap_page;
|
goto swap_page;
|
address &= PAGE_MASK;
|
address &= PAGE_MASK;
|
if (!vma->vm_ops || !vma->vm_ops->nopage)
|
if (!vma->vm_ops || !vma->vm_ops->nopage)
|
goto anonymous_page;
|
goto anonymous_page;
|
/*
|
/*
|
* The third argument is "no_share", which tells the low-level code
|
* The third argument is "no_share", which tells the low-level code
|
* to copy, not share the page even if sharing is possible. It's
|
* to copy, not share the page even if sharing is possible. It's
|
* essentially an early COW detection
|
* essentially an early COW detection
|
*/
|
*/
|
page = vma->vm_ops->nopage(vma, address,
|
page = vma->vm_ops->nopage(vma, address,
|
(vma->vm_flags & VM_SHARED)?0:write_access);
|
(vma->vm_flags & VM_SHARED)?0:write_access);
|
if (!page)
|
if (!page)
|
goto sigbus;
|
goto sigbus;
|
++tsk->maj_flt;
|
++tsk->maj_flt;
|
++vma->vm_mm->rss;
|
++vma->vm_mm->rss;
|
/*
|
/*
|
* This silly early PAGE_DIRTY setting removes a race
|
* This silly early PAGE_DIRTY setting removes a race
|
* due to the bad i386 page protection. But it's valid
|
* due to the bad i386 page protection. But it's valid
|
* for other architectures too.
|
* for other architectures too.
|
*
|
*
|
* Note that if write_access is true, we either now have
|
* Note that if write_access is true, we either now have
|
* a exclusive copy of the page, or this is a shared mapping,
|
* a exclusive copy of the page, or this is a shared mapping,
|
* so we can make it writable and dirty to avoid having to
|
* so we can make it writable and dirty to avoid having to
|
* handle that later.
|
* handle that later.
|
*/
|
*/
|
flush_page_to_ram(page);
|
flush_page_to_ram(page);
|
entry = mk_pte(page, vma->vm_page_prot);
|
entry = mk_pte(page, vma->vm_page_prot);
|
if (write_access) {
|
if (write_access) {
|
entry = pte_mkwrite(pte_mkdirty(entry));
|
entry = pte_mkwrite(pte_mkdirty(entry));
|
} else if (mem_map[MAP_NR(page)].count > 1 && !(vma->vm_flags & VM_SHARED))
|
} else if (mem_map[MAP_NR(page)].count > 1 && !(vma->vm_flags & VM_SHARED))
|
entry = pte_wrprotect(entry);
|
entry = pte_wrprotect(entry);
|
put_page(page_table, entry);
|
put_page(page_table, entry);
|
/* no need to invalidate: a not-present page shouldn't be cached */
|
/* no need to invalidate: a not-present page shouldn't be cached */
|
return;
|
return;
|
|
|
anonymous_page:
|
anonymous_page:
|
entry = pte_wrprotect(mk_pte(ZERO_PAGE, vma->vm_page_prot));
|
entry = pte_wrprotect(mk_pte(ZERO_PAGE, vma->vm_page_prot));
|
if (write_access) {
|
if (write_access) {
|
unsigned long page = __get_free_page(GFP_KERNEL);
|
unsigned long page = __get_free_page(GFP_KERNEL);
|
if (!page)
|
if (!page)
|
goto sigbus;
|
goto sigbus;
|
memset((void *) page, 0, PAGE_SIZE);
|
memset((void *) page, 0, PAGE_SIZE);
|
entry = pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
|
entry = pte_mkwrite(pte_mkdirty(mk_pte(page, vma->vm_page_prot)));
|
vma->vm_mm->rss++;
|
vma->vm_mm->rss++;
|
tsk->min_flt++;
|
tsk->min_flt++;
|
flush_page_to_ram(page);
|
flush_page_to_ram(page);
|
}
|
}
|
put_page(page_table, entry);
|
put_page(page_table, entry);
|
return;
|
return;
|
|
|
sigbus:
|
sigbus:
|
force_sig(SIGBUS, current);
|
force_sig(SIGBUS, current);
|
put_page(page_table, BAD_PAGE);
|
put_page(page_table, BAD_PAGE);
|
/* no need to invalidate, wasn't present */
|
/* no need to invalidate, wasn't present */
|
return;
|
return;
|
|
|
swap_page:
|
swap_page:
|
do_swap_page(tsk, vma, address, page_table, entry, write_access);
|
do_swap_page(tsk, vma, address, page_table, entry, write_access);
|
return;
|
return;
|
|
|
no_memory:
|
no_memory:
|
oom(tsk);
|
oom(tsk);
|
is_present:
|
is_present:
|
return;
|
return;
|
}
|
}
|
|
|
/*
|
/*
|
* The above separate functions for the no-page and wp-page
|
* The above separate functions for the no-page and wp-page
|
* cases will go away (they mostly do the same thing anyway),
|
* cases will go away (they mostly do the same thing anyway),
|
* and we'll instead use only a general "handle_mm_fault()".
|
* and we'll instead use only a general "handle_mm_fault()".
|
*
|
*
|
* These routines also need to handle stuff like marking pages dirty
|
* These routines also need to handle stuff like marking pages dirty
|
* and/or accessed for architectures that don't do it in hardware (most
|
* and/or accessed for architectures that don't do it in hardware (most
|
* RISC architectures). The early dirtying is also good on the i386.
|
* RISC architectures). The early dirtying is also good on the i386.
|
*
|
*
|
* There is also a hook called "update_mmu_cache()" that architectures
|
* There is also a hook called "update_mmu_cache()" that architectures
|
* with external mmu caches can use to update those (ie the Sparc or
|
* with external mmu caches can use to update those (ie the Sparc or
|
* PowerPC hashed page tables that act as extended TLBs).
|
* PowerPC hashed page tables that act as extended TLBs).
|
*/
|
*/
|
static inline void handle_pte_fault(struct vm_area_struct * vma, unsigned long address,
|
static inline void handle_pte_fault(struct vm_area_struct * vma, unsigned long address,
|
int write_access, pte_t * pte)
|
int write_access, pte_t * pte)
|
{
|
{
|
if (!pte_present(*pte)) {
|
if (!pte_present(*pte)) {
|
do_no_page(current, vma, address, write_access);
|
do_no_page(current, vma, address, write_access);
|
return;
|
return;
|
}
|
}
|
set_pte(pte, pte_mkyoung(*pte));
|
set_pte(pte, pte_mkyoung(*pte));
|
flush_tlb_page(vma, address);
|
flush_tlb_page(vma, address);
|
if (!write_access)
|
if (!write_access)
|
return;
|
return;
|
if (pte_write(*pte)) {
|
if (pte_write(*pte)) {
|
set_pte(pte, pte_mkdirty(*pte));
|
set_pte(pte, pte_mkdirty(*pte));
|
flush_tlb_page(vma, address);
|
flush_tlb_page(vma, address);
|
return;
|
return;
|
}
|
}
|
do_wp_page(current, vma, address, write_access);
|
do_wp_page(current, vma, address, write_access);
|
}
|
}
|
|
|
void handle_mm_fault(struct vm_area_struct * vma, unsigned long address,
|
void handle_mm_fault(struct vm_area_struct * vma, unsigned long address,
|
int write_access)
|
int write_access)
|
{
|
{
|
pgd_t *pgd;
|
pgd_t *pgd;
|
pmd_t *pmd;
|
pmd_t *pmd;
|
pte_t *pte;
|
pte_t *pte;
|
|
|
pgd = pgd_offset(vma->vm_mm, address);
|
pgd = pgd_offset(vma->vm_mm, address);
|
pmd = pmd_alloc(pgd, address);
|
pmd = pmd_alloc(pgd, address);
|
if (!pmd)
|
if (!pmd)
|
goto no_memory;
|
goto no_memory;
|
pte = pte_alloc(pmd, address);
|
pte = pte_alloc(pmd, address);
|
if (!pte)
|
if (!pte)
|
goto no_memory;
|
goto no_memory;
|
handle_pte_fault(vma, address, write_access, pte);
|
handle_pte_fault(vma, address, write_access, pte);
|
update_mmu_cache(vma, address, *pte);
|
update_mmu_cache(vma, address, *pte);
|
return;
|
return;
|
no_memory:
|
no_memory:
|
oom(current);
|
oom(current);
|
}
|
}
|
|
|
