5c8aaceab8
Map all of physical memory as executable to avoid having to change stack protections during fork and exit. unprotect_stack is now called only from MODE_TT code, so it is marked as such. Signed-off-by: Jeff Dike <jdike@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
228 lines
5.5 KiB
C
228 lines
5.5 KiB
C
/*
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* Copyright (C) 2000 - 2003 Jeff Dike (jdike@addtoit.com)
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* Licensed under the GPL
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*/
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#include "linux/mm.h"
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#include "linux/rbtree.h"
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#include "linux/slab.h"
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#include "linux/vmalloc.h"
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#include "linux/bootmem.h"
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#include "linux/module.h"
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#include "linux/pfn.h"
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#include "asm/types.h"
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#include "asm/pgtable.h"
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#include "kern_util.h"
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#include "as-layout.h"
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#include "mode_kern.h"
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#include "mem.h"
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#include "mem_user.h"
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#include "os.h"
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#include "kern.h"
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#include "init.h"
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static int physmem_fd = -1;
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/* Changed during early boot */
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unsigned long high_physmem;
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extern unsigned long long physmem_size;
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int __init init_maps(unsigned long physmem, unsigned long iomem,
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unsigned long highmem)
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{
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struct page *p, *map;
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unsigned long phys_len, phys_pages, highmem_len, highmem_pages;
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unsigned long iomem_len, iomem_pages, total_len, total_pages;
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int i;
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phys_pages = physmem >> PAGE_SHIFT;
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phys_len = phys_pages * sizeof(struct page);
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iomem_pages = iomem >> PAGE_SHIFT;
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iomem_len = iomem_pages * sizeof(struct page);
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highmem_pages = highmem >> PAGE_SHIFT;
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highmem_len = highmem_pages * sizeof(struct page);
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total_pages = phys_pages + iomem_pages + highmem_pages;
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total_len = phys_len + iomem_len + highmem_len;
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map = alloc_bootmem_low_pages(total_len);
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if(map == NULL)
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return -ENOMEM;
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for(i = 0; i < total_pages; i++){
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p = &map[i];
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memset(p, 0, sizeof(struct page));
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SetPageReserved(p);
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INIT_LIST_HEAD(&p->lru);
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}
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max_mapnr = total_pages;
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return 0;
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}
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/* Changed during early boot */
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static unsigned long kmem_top = 0;
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unsigned long get_kmem_end(void)
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{
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if(kmem_top == 0)
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kmem_top = CHOOSE_MODE(kmem_end_tt, kmem_end_skas);
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return kmem_top;
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}
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void map_memory(unsigned long virt, unsigned long phys, unsigned long len,
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int r, int w, int x)
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{
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__u64 offset;
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int fd, err;
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fd = phys_mapping(phys, &offset);
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err = os_map_memory((void *) virt, fd, offset, len, r, w, x);
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if(err) {
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if(err == -ENOMEM)
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printk("try increasing the host's "
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"/proc/sys/vm/max_map_count to <physical "
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"memory size>/4096\n");
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panic("map_memory(0x%lx, %d, 0x%llx, %ld, %d, %d, %d) failed, "
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"err = %d\n", virt, fd, offset, len, r, w, x, err);
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}
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}
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extern int __syscall_stub_start;
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void __init setup_physmem(unsigned long start, unsigned long reserve_end,
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unsigned long len, unsigned long long highmem)
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{
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unsigned long reserve = reserve_end - start;
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int pfn = PFN_UP(__pa(reserve_end));
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int delta = (len - reserve) >> PAGE_SHIFT;
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int err, offset, bootmap_size;
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physmem_fd = create_mem_file(len + highmem);
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offset = uml_reserved - uml_physmem;
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err = os_map_memory((void *) uml_reserved, physmem_fd, offset,
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len - offset, 1, 1, 1);
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if(err < 0){
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os_print_error(err, "Mapping memory");
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exit(1);
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}
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/* Special kludge - This page will be mapped in to userspace processes
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* from physmem_fd, so it needs to be written out there.
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*/
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os_seek_file(physmem_fd, __pa(&__syscall_stub_start));
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os_write_file(physmem_fd, &__syscall_stub_start, PAGE_SIZE);
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bootmap_size = init_bootmem(pfn, pfn + delta);
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free_bootmem(__pa(reserve_end) + bootmap_size,
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len - bootmap_size - reserve);
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}
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int phys_mapping(unsigned long phys, __u64 *offset_out)
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{
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int fd = -1;
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if(phys < physmem_size){
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fd = physmem_fd;
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*offset_out = phys;
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}
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else if(phys < __pa(end_iomem)){
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struct iomem_region *region = iomem_regions;
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while(region != NULL){
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if((phys >= region->phys) &&
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(phys < region->phys + region->size)){
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fd = region->fd;
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*offset_out = phys - region->phys;
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break;
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}
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region = region->next;
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}
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}
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else if(phys < __pa(end_iomem) + highmem){
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fd = physmem_fd;
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*offset_out = phys - iomem_size;
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}
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return fd;
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}
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static int __init uml_mem_setup(char *line, int *add)
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{
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char *retptr;
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physmem_size = memparse(line,&retptr);
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return 0;
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}
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__uml_setup("mem=", uml_mem_setup,
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"mem=<Amount of desired ram>\n"
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" This controls how much \"physical\" memory the kernel allocates\n"
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" for the system. The size is specified as a number followed by\n"
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" one of 'k', 'K', 'm', 'M', which have the obvious meanings.\n"
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" This is not related to the amount of memory in the host. It can\n"
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" be more, and the excess, if it's ever used, will just be swapped out.\n"
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" Example: mem=64M\n\n"
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);
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extern int __init parse_iomem(char *str, int *add);
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__uml_setup("iomem=", parse_iomem,
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"iomem=<name>,<file>\n"
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" Configure <file> as an IO memory region named <name>.\n\n"
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);
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/*
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* This list is constructed in parse_iomem and addresses filled in in
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* setup_iomem, both of which run during early boot. Afterwards, it's
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* unchanged.
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*/
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struct iomem_region *iomem_regions = NULL;
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/* Initialized in parse_iomem */
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int iomem_size = 0;
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unsigned long find_iomem(char *driver, unsigned long *len_out)
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{
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struct iomem_region *region = iomem_regions;
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while(region != NULL){
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if(!strcmp(region->driver, driver)){
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*len_out = region->size;
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return region->virt;
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}
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region = region->next;
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}
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return 0;
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}
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int setup_iomem(void)
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{
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struct iomem_region *region = iomem_regions;
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unsigned long iomem_start = high_physmem + PAGE_SIZE;
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int err;
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while(region != NULL){
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err = os_map_memory((void *) iomem_start, region->fd, 0,
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region->size, 1, 1, 0);
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if(err)
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printk("Mapping iomem region for driver '%s' failed, "
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"errno = %d\n", region->driver, -err);
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else {
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region->virt = iomem_start;
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region->phys = __pa(region->virt);
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}
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iomem_start += region->size + PAGE_SIZE;
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region = region->next;
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}
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return 0;
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}
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__initcall(setup_iomem);
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