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d882b17251
linux/arch/s390/mm/init.c
Heiko Carstens d882b17251 [PATCH] s390: put sys_call_table into .rodata section and write protect it 
Put s390's syscall tables into .rodata section and write protect this
section to prevent misuse of it.  Suggested by Arjan van de Ven
<arjan@infradead.org>.

Cc: Arjan van de Ven <arjan@infradead.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-07-01 09:56:04 -07:00

322 lines
9.3 KiB
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/*
* arch/s390/mm/init.c
*
* S390 version
* Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
* Author(s): Hartmut Penner (hp@de.ibm.com)
*
* Derived from "arch/i386/mm/init.c"
* Copyright (C) 1995 Linus Torvalds
*/
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/pfn.h>
#include <asm/processor.h>
#include <asm/system.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/lowcore.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/sections.h>
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
pgd_t swapper_pg_dir[PTRS_PER_PGD] __attribute__((__aligned__(PAGE_SIZE)));
char empty_zero_page[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
void diag10(unsigned long addr)
{
if (addr >= 0x7ff00000)
return;
#ifdef CONFIG_64BIT
asm volatile (
" sam31\n"
" diag %0,%0,0x10\n"
"0: sam64\n"
".section __ex_table,\"a\"\n"
" .align 8\n"
" .quad 0b, 0b\n"
".previous\n"
: : "a" (addr));
#else
asm volatile (
" diag %0,%0,0x10\n"
"0:\n"
".section __ex_table,\"a\"\n"
" .align 4\n"
" .long 0b, 0b\n"
".previous\n"
: : "a" (addr));
#endif
}
void show_mem(void)
{
int i, total = 0, reserved = 0;
int shared = 0, cached = 0;
printk("Mem-info:\n");
show_free_areas();
printk("Free swap: %6ldkB\n", nr_swap_pages<<(PAGE_SHIFT-10));
i = max_mapnr;
while (i-- > 0) {
total++;
if (PageReserved(mem_map+i))
reserved++;
else if (PageSwapCache(mem_map+i))
cached++;
else if (page_count(mem_map+i))
shared += page_count(mem_map+i) - 1;
}
printk("%d pages of RAM\n",total);
printk("%d reserved pages\n",reserved);
printk("%d pages shared\n",shared);
printk("%d pages swap cached\n",cached);
}
extern unsigned long __initdata zholes_size[];
/*
* paging_init() sets up the page tables
*/
#ifndef CONFIG_64BIT
void __init paging_init(void)
{
pgd_t * pg_dir;
pte_t * pg_table;
pte_t pte;
int i;
unsigned long tmp;
unsigned long pfn = 0;
unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) | _KERNSEG_TABLE;
static const int ssm_mask = 0x04000000L;
unsigned long ro_start_pfn, ro_end_pfn;
ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
/* unmap whole virtual address space */
pg_dir = swapper_pg_dir;
for (i=0;i<KERNEL_PGD_PTRS;i++)
pmd_clear((pmd_t*)pg_dir++);
/*
* map whole physical memory to virtual memory (identity mapping)
*/
pg_dir = swapper_pg_dir;
while (pfn < max_low_pfn) {
/*
* pg_table is physical at this point
*/
pg_table = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
pg_dir->pgd0 = (_PAGE_TABLE | __pa(pg_table));
pg_dir->pgd1 = (_PAGE_TABLE | (__pa(pg_table)+1024));
pg_dir->pgd2 = (_PAGE_TABLE | (__pa(pg_table)+2048));
pg_dir->pgd3 = (_PAGE_TABLE | (__pa(pg_table)+3072));
pg_dir++;
for (tmp = 0 ; tmp < PTRS_PER_PTE ; tmp++,pg_table++) {
if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
else
pte = pfn_pte(pfn, PAGE_KERNEL);
if (pfn >= max_low_pfn)
pte_clear(&init_mm, 0, &pte);
set_pte(pg_table, pte);
pfn++;
}
}
S390_lowcore.kernel_asce = pgdir_k;
/* enable virtual mapping in kernel mode */
__asm__ __volatile__(" LCTL 1,1,%0\n"
" LCTL 7,7,%0\n"
" LCTL 13,13,%0\n"
" SSM %1"
: : "m" (pgdir_k), "m" (ssm_mask));
local_flush_tlb();
{
unsigned long zones_size[MAX_NR_ZONES];
memset(zones_size, 0, sizeof(zones_size));
zones_size[ZONE_DMA] = max_low_pfn;
free_area_init_node(0, &contig_page_data, zones_size,
__pa(PAGE_OFFSET) >> PAGE_SHIFT,
zholes_size);
}
return;
}
#else /* CONFIG_64BIT */
void __init paging_init(void)
{
pgd_t * pg_dir;
pmd_t * pm_dir;
pte_t * pt_dir;
pte_t pte;
int i,j,k;
unsigned long pfn = 0;
unsigned long pgdir_k = (__pa(swapper_pg_dir) & PAGE_MASK) |
_KERN_REGION_TABLE;
static const int ssm_mask = 0x04000000L;
unsigned long zones_size[MAX_NR_ZONES];
unsigned long dma_pfn, high_pfn;
unsigned long ro_start_pfn, ro_end_pfn;
memset(zones_size, 0, sizeof(zones_size));
dma_pfn = MAX_DMA_ADDRESS >> PAGE_SHIFT;
high_pfn = max_low_pfn;
ro_start_pfn = PFN_DOWN((unsigned long)&__start_rodata);
ro_end_pfn = PFN_UP((unsigned long)&__end_rodata);
if (dma_pfn > high_pfn)
zones_size[ZONE_DMA] = high_pfn;
else {
zones_size[ZONE_DMA] = dma_pfn;
zones_size[ZONE_NORMAL] = high_pfn - dma_pfn;
}
/* Initialize mem_map[]. */
free_area_init_node(0, &contig_page_data, zones_size,
__pa(PAGE_OFFSET) >> PAGE_SHIFT, zholes_size);
/*
* map whole physical memory to virtual memory (identity mapping)
*/
pg_dir = swapper_pg_dir;
for (i = 0 ; i < PTRS_PER_PGD ; i++,pg_dir++) {
if (pfn >= max_low_pfn) {
pgd_clear(pg_dir);
continue;
}
pm_dir = (pmd_t *) alloc_bootmem_low_pages(PAGE_SIZE*4);
pgd_populate(&init_mm, pg_dir, pm_dir);
for (j = 0 ; j < PTRS_PER_PMD ; j++,pm_dir++) {
if (pfn >= max_low_pfn) {
pmd_clear(pm_dir);
continue;
}
pt_dir = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE);
pmd_populate_kernel(&init_mm, pm_dir, pt_dir);
for (k = 0 ; k < PTRS_PER_PTE ; k++,pt_dir++) {
if (pfn >= ro_start_pfn && pfn < ro_end_pfn)
pte = pfn_pte(pfn, __pgprot(_PAGE_RO));
else
pte = pfn_pte(pfn, PAGE_KERNEL);
if (pfn >= max_low_pfn) {
pte_clear(&init_mm, 0, &pte);
continue;
}
set_pte(pt_dir, pte);
pfn++;
}
}
}
S390_lowcore.kernel_asce = pgdir_k;
/* enable virtual mapping in kernel mode */
__asm__ __volatile__("lctlg 1,1,%0\n\t"
"lctlg 7,7,%0\n\t"
"lctlg 13,13,%0\n\t"
"ssm %1"
: :"m" (pgdir_k), "m" (ssm_mask));
local_flush_tlb();
return;
}
#endif /* CONFIG_64BIT */
void __init mem_init(void)
{
unsigned long codesize, reservedpages, datasize, initsize;
max_mapnr = num_physpages = max_low_pfn;
high_memory = (void *) __va(max_low_pfn * PAGE_SIZE);
/* clear the zero-page */
memset(empty_zero_page, 0, PAGE_SIZE);
/* this will put all low memory onto the freelists */
totalram_pages += free_all_bootmem();
reservedpages = 0;
codesize = (unsigned long) &_etext - (unsigned long) &_text;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
printk("Memory: %luk/%luk available (%ldk kernel code, %ldk reserved, %ldk data, %ldk init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
max_mapnr << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >>10,
initsize >> 10);
printk("Write protected kernel read-only data: %#lx - %#lx\n",
(unsigned long)&__start_rodata,
PFN_ALIGN((unsigned long)&__end_rodata) - 1);
}
void free_initmem(void)
{
unsigned long addr;
addr = (unsigned long)(&__init_begin);
for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
printk ("Freeing unused kernel memory: %ldk freed\n",
((unsigned long)&__init_end - (unsigned long)&__init_begin) >> 10);
}
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
if (start < end)
printk ("Freeing initrd memory: %ldk freed\n", (end - start) >> 10);
for (; start < end; start += PAGE_SIZE) {
ClearPageReserved(virt_to_page(start));
init_page_count(virt_to_page(start));
free_page(start);
totalram_pages++;
}
}
#endif
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