android_kernel_motorola_sm6225/arch/x86/mm/init_64.c
Arjan van de Ven ae531c26c5 x86: introduce /dev/mem restrictions with a config option
This patch introduces a restriction on /dev/mem: Only non-memory can be
read or written unless the newly introduced config option is set.

The X server needs access to /dev/mem for the PCI space, but it doesn't need
access to memory; both the file permissions and SELinux permissions of /dev/mem
just make X effectively super-super powerful. With the exception of the
BIOS area, there's just no valid app that uses /dev/mem on actual memory.
Other popular users of /dev/mem are rootkits and the like.
(note: mmap access of memory via /dev/mem was already not allowed since
a really long time)

People who want to use /dev/mem for kernel debugging can enable the config
option.

The restrictions of this patch have been in the Fedora and RHEL kernels for
at least 4 years without any problems.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2008-04-24 23:40:47 +02:00

972 lines
23 KiB
C

/*
* linux/arch/x86_64/mm/init.c
*
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 2000 Pavel Machek <pavel@suse.cz>
* Copyright (C) 2002,2003 Andi Kleen <ak@suse.de>
*/
#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/proc_fs.h>
#include <linux/pci.h>
#include <linux/pfn.h>
#include <linux/poison.h>
#include <linux/dma-mapping.h>
#include <linux/module.h>
#include <linux/memory_hotplug.h>
#include <linux/nmi.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/fixmap.h>
#include <asm/e820.h>
#include <asm/apic.h>
#include <asm/tlb.h>
#include <asm/mmu_context.h>
#include <asm/proto.h>
#include <asm/smp.h>
#include <asm/sections.h>
#include <asm/kdebug.h>
#include <asm/numa.h>
#include <asm/cacheflush.h>
static unsigned long dma_reserve __initdata;
DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
int direct_gbpages __meminitdata
#ifdef CONFIG_DIRECT_GBPAGES
= 1
#endif
;
static int __init parse_direct_gbpages_off(char *arg)
{
direct_gbpages = 0;
return 0;
}
early_param("nogbpages", parse_direct_gbpages_off);
static int __init parse_direct_gbpages_on(char *arg)
{
direct_gbpages = 1;
return 0;
}
early_param("gbpages", parse_direct_gbpages_on);
/*
* NOTE: pagetable_init alloc all the fixmap pagetables contiguous on the
* physical space so we can cache the place of the first one and move
* around without checking the pgd every time.
*/
void show_mem(void)
{
long i, total = 0, reserved = 0;
long shared = 0, cached = 0;
struct page *page;
pg_data_t *pgdat;
printk(KERN_INFO "Mem-info:\n");
show_free_areas();
for_each_online_pgdat(pgdat) {
for (i = 0; i < pgdat->node_spanned_pages; ++i) {
/*
* This loop can take a while with 256 GB and
* 4k pages so defer the NMI watchdog:
*/
if (unlikely(i % MAX_ORDER_NR_PAGES == 0))
touch_nmi_watchdog();
if (!pfn_valid(pgdat->node_start_pfn + i))
continue;
page = pfn_to_page(pgdat->node_start_pfn + i);
total++;
if (PageReserved(page))
reserved++;
else if (PageSwapCache(page))
cached++;
else if (page_count(page))
shared += page_count(page) - 1;
}
}
printk(KERN_INFO "%lu pages of RAM\n", total);
printk(KERN_INFO "%lu reserved pages\n", reserved);
printk(KERN_INFO "%lu pages shared\n", shared);
printk(KERN_INFO "%lu pages swap cached\n", cached);
}
int after_bootmem;
static __init void *spp_getpage(void)
{
void *ptr;
if (after_bootmem)
ptr = (void *) get_zeroed_page(GFP_ATOMIC);
else
ptr = alloc_bootmem_pages(PAGE_SIZE);
if (!ptr || ((unsigned long)ptr & ~PAGE_MASK)) {
panic("set_pte_phys: cannot allocate page data %s\n",
after_bootmem ? "after bootmem" : "");
}
pr_debug("spp_getpage %p\n", ptr);
return ptr;
}
static __init void
set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte, new_pte;
pr_debug("set_pte_phys %lx to %lx\n", vaddr, phys);
pgd = pgd_offset_k(vaddr);
if (pgd_none(*pgd)) {
printk(KERN_ERR
"PGD FIXMAP MISSING, it should be setup in head.S!\n");
return;
}
pud = pud_offset(pgd, vaddr);
if (pud_none(*pud)) {
pmd = (pmd_t *) spp_getpage();
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE | _PAGE_USER));
if (pmd != pmd_offset(pud, 0)) {
printk(KERN_ERR "PAGETABLE BUG #01! %p <-> %p\n",
pmd, pmd_offset(pud, 0));
return;
}
}
pmd = pmd_offset(pud, vaddr);
if (pmd_none(*pmd)) {
pte = (pte_t *) spp_getpage();
set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE | _PAGE_USER));
if (pte != pte_offset_kernel(pmd, 0)) {
printk(KERN_ERR "PAGETABLE BUG #02!\n");
return;
}
}
new_pte = pfn_pte(phys >> PAGE_SHIFT, prot);
pte = pte_offset_kernel(pmd, vaddr);
if (!pte_none(*pte) &&
pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask))
pte_ERROR(*pte);
set_pte(pte, new_pte);
/*
* It's enough to flush this one mapping.
* (PGE mappings get flushed as well)
*/
__flush_tlb_one(vaddr);
}
/*
* The head.S code sets up the kernel high mapping:
*
* from __START_KERNEL_map to __START_KERNEL_map + size (== _end-_text)
*
* phys_addr holds the negative offset to the kernel, which is added
* to the compile time generated pmds. This results in invalid pmds up
* to the point where we hit the physaddr 0 mapping.
*
* We limit the mappings to the region from _text to _end. _end is
* rounded up to the 2MB boundary. This catches the invalid pmds as
* well, as they are located before _text:
*/
void __init cleanup_highmap(void)
{
unsigned long vaddr = __START_KERNEL_map;
unsigned long end = round_up((unsigned long)_end, PMD_SIZE) - 1;
pmd_t *pmd = level2_kernel_pgt;
pmd_t *last_pmd = pmd + PTRS_PER_PMD;
for (; pmd < last_pmd; pmd++, vaddr += PMD_SIZE) {
if (!pmd_present(*pmd))
continue;
if (vaddr < (unsigned long) _text || vaddr > end)
set_pmd(pmd, __pmd(0));
}
}
/* NOTE: this is meant to be run only at boot */
void __init
__set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
{
unsigned long address = __fix_to_virt(idx);
if (idx >= __end_of_fixed_addresses) {
printk(KERN_ERR "Invalid __set_fixmap\n");
return;
}
set_pte_phys(address, phys, prot);
}
static unsigned long __initdata table_start;
static unsigned long __meminitdata table_end;
static __meminit void *alloc_low_page(unsigned long *phys)
{
unsigned long pfn = table_end++;
void *adr;
if (after_bootmem) {
adr = (void *)get_zeroed_page(GFP_ATOMIC);
*phys = __pa(adr);
return adr;
}
if (pfn >= end_pfn)
panic("alloc_low_page: ran out of memory");
adr = early_ioremap(pfn * PAGE_SIZE, PAGE_SIZE);
memset(adr, 0, PAGE_SIZE);
*phys = pfn * PAGE_SIZE;
return adr;
}
static __meminit void unmap_low_page(void *adr)
{
if (after_bootmem)
return;
early_iounmap(adr, PAGE_SIZE);
}
/* Must run before zap_low_mappings */
__meminit void *early_ioremap(unsigned long addr, unsigned long size)
{
pmd_t *pmd, *last_pmd;
unsigned long vaddr;
int i, pmds;
pmds = ((addr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
vaddr = __START_KERNEL_map;
pmd = level2_kernel_pgt;
last_pmd = level2_kernel_pgt + PTRS_PER_PMD - 1;
for (; pmd <= last_pmd; pmd++, vaddr += PMD_SIZE) {
for (i = 0; i < pmds; i++) {
if (pmd_present(pmd[i]))
goto continue_outer_loop;
}
vaddr += addr & ~PMD_MASK;
addr &= PMD_MASK;
for (i = 0; i < pmds; i++, addr += PMD_SIZE)
set_pmd(pmd+i, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC));
__flush_tlb_all();
return (void *)vaddr;
continue_outer_loop:
;
}
printk(KERN_ERR "early_ioremap(0x%lx, %lu) failed\n", addr, size);
return NULL;
}
/*
* To avoid virtual aliases later:
*/
__meminit void early_iounmap(void *addr, unsigned long size)
{
unsigned long vaddr;
pmd_t *pmd;
int i, pmds;
vaddr = (unsigned long)addr;
pmds = ((vaddr & ~PMD_MASK) + size + ~PMD_MASK) / PMD_SIZE;
pmd = level2_kernel_pgt + pmd_index(vaddr);
for (i = 0; i < pmds; i++)
pmd_clear(pmd + i);
__flush_tlb_all();
}
static unsigned long __meminit
phys_pmd_init(pmd_t *pmd_page, unsigned long address, unsigned long end)
{
int i = pmd_index(address);
for (; i < PTRS_PER_PMD; i++, address += PMD_SIZE) {
pmd_t *pmd = pmd_page + pmd_index(address);
if (address >= end) {
if (!after_bootmem) {
for (; i < PTRS_PER_PMD; i++, pmd++)
set_pmd(pmd, __pmd(0));
}
break;
}
if (pmd_val(*pmd))
continue;
set_pte((pte_t *)pmd,
pfn_pte(address >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
}
return address;
}
static unsigned long __meminit
phys_pmd_update(pud_t *pud, unsigned long address, unsigned long end)
{
pmd_t *pmd = pmd_offset(pud, 0);
unsigned long last_map_addr;
spin_lock(&init_mm.page_table_lock);
last_map_addr = phys_pmd_init(pmd, address, end);
spin_unlock(&init_mm.page_table_lock);
__flush_tlb_all();
return last_map_addr;
}
static unsigned long __meminit
phys_pud_init(pud_t *pud_page, unsigned long addr, unsigned long end)
{
unsigned long last_map_addr = end;
int i = pud_index(addr);
for (; i < PTRS_PER_PUD; i++, addr = (addr & PUD_MASK) + PUD_SIZE) {
unsigned long pmd_phys;
pud_t *pud = pud_page + pud_index(addr);
pmd_t *pmd;
if (addr >= end)
break;
if (!after_bootmem &&
!e820_any_mapped(addr, addr+PUD_SIZE, 0)) {
set_pud(pud, __pud(0));
continue;
}
if (pud_val(*pud)) {
if (!pud_large(*pud))
last_map_addr = phys_pmd_update(pud, addr, end);
continue;
}
if (direct_gbpages) {
set_pte((pte_t *)pud,
pfn_pte(addr >> PAGE_SHIFT, PAGE_KERNEL_LARGE));
last_map_addr = (addr & PUD_MASK) + PUD_SIZE;
continue;
}
pmd = alloc_low_page(&pmd_phys);
spin_lock(&init_mm.page_table_lock);
set_pud(pud, __pud(pmd_phys | _KERNPG_TABLE));
last_map_addr = phys_pmd_init(pmd, addr, end);
spin_unlock(&init_mm.page_table_lock);
unmap_low_page(pmd);
}
__flush_tlb_all();
return last_map_addr >> PAGE_SHIFT;
}
static void __init find_early_table_space(unsigned long end)
{
unsigned long puds, pmds, tables, start;
puds = (end + PUD_SIZE - 1) >> PUD_SHIFT;
tables = round_up(puds * sizeof(pud_t), PAGE_SIZE);
if (!direct_gbpages) {
pmds = (end + PMD_SIZE - 1) >> PMD_SHIFT;
tables += round_up(pmds * sizeof(pmd_t), PAGE_SIZE);
}
/*
* RED-PEN putting page tables only on node 0 could
* cause a hotspot and fill up ZONE_DMA. The page tables
* need roughly 0.5KB per GB.
*/
start = 0x8000;
table_start = find_e820_area(start, end, tables, PAGE_SIZE);
if (table_start == -1UL)
panic("Cannot find space for the kernel page tables");
table_start >>= PAGE_SHIFT;
table_end = table_start;
early_printk("kernel direct mapping tables up to %lx @ %lx-%lx\n",
end, table_start << PAGE_SHIFT,
(table_start << PAGE_SHIFT) + tables);
}
static void __init init_gbpages(void)
{
if (direct_gbpages && cpu_has_gbpages)
printk(KERN_INFO "Using GB pages for direct mapping\n");
else
direct_gbpages = 0;
}
#ifdef CONFIG_MEMTEST_BOOTPARAM
static void __init memtest(unsigned long start_phys, unsigned long size,
unsigned pattern)
{
unsigned long i;
unsigned long *start;
unsigned long start_bad;
unsigned long last_bad;
unsigned long val;
unsigned long start_phys_aligned;
unsigned long count;
unsigned long incr;
switch (pattern) {
case 0:
val = 0UL;
break;
case 1:
val = -1UL;
break;
case 2:
val = 0x5555555555555555UL;
break;
case 3:
val = 0xaaaaaaaaaaaaaaaaUL;
break;
default:
return;
}
incr = sizeof(unsigned long);
start_phys_aligned = ALIGN(start_phys, incr);
count = (size - (start_phys_aligned - start_phys))/incr;
start = __va(start_phys_aligned);
start_bad = 0;
last_bad = 0;
for (i = 0; i < count; i++)
start[i] = val;
for (i = 0; i < count; i++, start++, start_phys_aligned += incr) {
if (*start != val) {
if (start_phys_aligned == last_bad + incr) {
last_bad += incr;
} else {
if (start_bad) {
printk(KERN_CONT "\n %016lx bad mem addr %016lx - %016lx reserved",
val, start_bad, last_bad + incr);
reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
}
start_bad = last_bad = start_phys_aligned;
}
}
}
if (start_bad) {
printk(KERN_CONT "\n %016lx bad mem addr %016lx - %016lx reserved",
val, start_bad, last_bad + incr);
reserve_early(start_bad, last_bad - start_bad, "BAD RAM");
}
}
static int memtest_pattern __initdata = CONFIG_MEMTEST_BOOTPARAM_VALUE;
static int __init parse_memtest(char *arg)
{
if (arg)
memtest_pattern = simple_strtoul(arg, NULL, 0);
return 0;
}
early_param("memtest", parse_memtest);
static void __init early_memtest(unsigned long start, unsigned long end)
{
unsigned long t_start, t_size;
unsigned pattern;
if (!memtest_pattern)
return;
printk(KERN_INFO "early_memtest: pattern num %d", memtest_pattern);
for (pattern = 0; pattern < memtest_pattern; pattern++) {
t_start = start;
t_size = 0;
while (t_start < end) {
t_start = find_e820_area_size(t_start, &t_size, 1);
/* done ? */
if (t_start >= end)
break;
if (t_start + t_size > end)
t_size = end - t_start;
printk(KERN_CONT "\n %016lx - %016lx pattern %d",
t_start, t_start + t_size, pattern);
memtest(t_start, t_size, pattern);
t_start += t_size;
}
}
printk(KERN_CONT "\n");
}
#else
static void __init early_memtest(unsigned long start, unsigned long end)
{
}
#endif
/*
* Setup the direct mapping of the physical memory at PAGE_OFFSET.
* This runs before bootmem is initialized and gets pages directly from
* the physical memory. To access them they are temporarily mapped.
*/
unsigned long __init_refok init_memory_mapping(unsigned long start, unsigned long end)
{
unsigned long next, last_map_addr = end;
unsigned long start_phys = start, end_phys = end;
printk(KERN_INFO "init_memory_mapping\n");
/*
* Find space for the kernel direct mapping tables.
*
* Later we should allocate these tables in the local node of the
* memory mapped. Unfortunately this is done currently before the
* nodes are discovered.
*/
if (!after_bootmem) {
init_gbpages();
find_early_table_space(end);
}
start = (unsigned long)__va(start);
end = (unsigned long)__va(end);
for (; start < end; start = next) {
pgd_t *pgd = pgd_offset_k(start);
unsigned long pud_phys;
pud_t *pud;
if (after_bootmem)
pud = pud_offset(pgd, start & PGDIR_MASK);
else
pud = alloc_low_page(&pud_phys);
next = start + PGDIR_SIZE;
if (next > end)
next = end;
last_map_addr = phys_pud_init(pud, __pa(start), __pa(next));
if (!after_bootmem)
set_pgd(pgd_offset_k(start), mk_kernel_pgd(pud_phys));
unmap_low_page(pud);
}
if (!after_bootmem)
mmu_cr4_features = read_cr4();
__flush_tlb_all();
if (!after_bootmem)
reserve_early(table_start << PAGE_SHIFT,
table_end << PAGE_SHIFT, "PGTABLE");
if (!after_bootmem)
early_memtest(start_phys, end_phys);
return last_map_addr;
}
#ifndef CONFIG_NUMA
void __init paging_init(void)
{
unsigned long max_zone_pfns[MAX_NR_ZONES];
memset(max_zone_pfns, 0, sizeof(max_zone_pfns));
max_zone_pfns[ZONE_DMA] = MAX_DMA_PFN;
max_zone_pfns[ZONE_DMA32] = MAX_DMA32_PFN;
max_zone_pfns[ZONE_NORMAL] = end_pfn;
memory_present(0, 0, end_pfn);
sparse_init();
free_area_init_nodes(max_zone_pfns);
}
#endif
/*
* Memory hotplug specific functions
*/
void online_page(struct page *page)
{
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
totalram_pages++;
num_physpages++;
}
#ifdef CONFIG_MEMORY_HOTPLUG
/*
* Memory is added always to NORMAL zone. This means you will never get
* additional DMA/DMA32 memory.
*/
int arch_add_memory(int nid, u64 start, u64 size)
{
struct pglist_data *pgdat = NODE_DATA(nid);
struct zone *zone = pgdat->node_zones + ZONE_NORMAL;
unsigned long last_mapped_pfn, start_pfn = start >> PAGE_SHIFT;
unsigned long nr_pages = size >> PAGE_SHIFT;
int ret;
last_mapped_pfn = init_memory_mapping(start, start + size-1);
if (last_mapped_pfn > max_pfn_mapped)
max_pfn_mapped = last_mapped_pfn;
ret = __add_pages(zone, start_pfn, nr_pages);
WARN_ON(1);
return ret;
}
EXPORT_SYMBOL_GPL(arch_add_memory);
#if !defined(CONFIG_ACPI_NUMA) && defined(CONFIG_NUMA)
int memory_add_physaddr_to_nid(u64 start)
{
return 0;
}
EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#endif
#endif /* CONFIG_MEMORY_HOTPLUG */
/*
* devmem_is_allowed() checks to see if /dev/mem access to a certain address
* is valid. The argument is a physical page number.
*
*
* On x86, access has to be given to the first megabyte of ram because that area
* contains bios code and data regions used by X and dosemu and similar apps.
* Access has to be given to non-kernel-ram areas as well, these contain the PCI
* mmio resources as well as potential bios/acpi data regions.
*/
int devmem_is_allowed(unsigned long pagenr)
{
if (pagenr <= 256)
return 1;
if (!page_is_ram(pagenr))
return 1;
return 0;
}
static struct kcore_list kcore_mem, kcore_vmalloc, kcore_kernel,
kcore_modules, kcore_vsyscall;
void __init mem_init(void)
{
long codesize, reservedpages, datasize, initsize;
pci_iommu_alloc();
/* clear_bss() already clear the empty_zero_page */
reservedpages = 0;
/* this will put all low memory onto the freelists */
#ifdef CONFIG_NUMA
totalram_pages = numa_free_all_bootmem();
#else
totalram_pages = free_all_bootmem();
#endif
reservedpages = end_pfn - totalram_pages -
absent_pages_in_range(0, end_pfn);
after_bootmem = 1;
codesize = (unsigned long) &_etext - (unsigned long) &_text;
datasize = (unsigned long) &_edata - (unsigned long) &_etext;
initsize = (unsigned long) &__init_end - (unsigned long) &__init_begin;
/* Register memory areas for /proc/kcore */
kclist_add(&kcore_mem, __va(0), max_low_pfn << PAGE_SHIFT);
kclist_add(&kcore_vmalloc, (void *)VMALLOC_START,
VMALLOC_END-VMALLOC_START);
kclist_add(&kcore_kernel, &_stext, _end - _stext);
kclist_add(&kcore_modules, (void *)MODULES_VADDR, MODULES_LEN);
kclist_add(&kcore_vsyscall, (void *)VSYSCALL_START,
VSYSCALL_END - VSYSCALL_START);
printk(KERN_INFO "Memory: %luk/%luk available (%ldk kernel code, "
"%ldk reserved, %ldk data, %ldk init)\n",
(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
end_pfn << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
initsize >> 10);
cpa_init();
}
void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
unsigned long addr = begin;
if (addr >= end)
return;
/*
* If debugging page accesses then do not free this memory but
* mark them not present - any buggy init-section access will
* create a kernel page fault:
*/
#ifdef CONFIG_DEBUG_PAGEALLOC
printk(KERN_INFO "debug: unmapping init memory %08lx..%08lx\n",
begin, PAGE_ALIGN(end));
set_memory_np(begin, (end - begin) >> PAGE_SHIFT);
#else
printk(KERN_INFO "Freeing %s: %luk freed\n", what, (end - begin) >> 10);
for (; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
memset((void *)(addr & ~(PAGE_SIZE-1)),
POISON_FREE_INITMEM, PAGE_SIZE);
free_page(addr);
totalram_pages++;
}
#endif
}
void free_initmem(void)
{
free_init_pages("unused kernel memory",
(unsigned long)(&__init_begin),
(unsigned long)(&__init_end));
}
#ifdef CONFIG_DEBUG_RODATA
const int rodata_test_data = 0xC3;
EXPORT_SYMBOL_GPL(rodata_test_data);
void mark_rodata_ro(void)
{
unsigned long start = PFN_ALIGN(_stext), end = PFN_ALIGN(__end_rodata);
printk(KERN_INFO "Write protecting the kernel read-only data: %luk\n",
(end - start) >> 10);
set_memory_ro(start, (end - start) >> PAGE_SHIFT);
/*
* The rodata section (but not the kernel text!) should also be
* not-executable.
*/
start = ((unsigned long)__start_rodata + PAGE_SIZE - 1) & PAGE_MASK;
set_memory_nx(start, (end - start) >> PAGE_SHIFT);
rodata_test();
#ifdef CONFIG_CPA_DEBUG
printk(KERN_INFO "Testing CPA: undo %lx-%lx\n", start, end);
set_memory_rw(start, (end-start) >> PAGE_SHIFT);
printk(KERN_INFO "Testing CPA: again\n");
set_memory_ro(start, (end-start) >> PAGE_SHIFT);
#endif
}
#endif
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
free_init_pages("initrd memory", start, end);
}
#endif
void __init reserve_bootmem_generic(unsigned long phys, unsigned len)
{
#ifdef CONFIG_NUMA
int nid = phys_to_nid(phys);
#endif
unsigned long pfn = phys >> PAGE_SHIFT;
if (pfn >= end_pfn) {
/*
* This can happen with kdump kernels when accessing
* firmware tables:
*/
if (pfn < max_pfn_mapped)
return;
printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n",
phys, len);
return;
}
/* Should check here against the e820 map to avoid double free */
#ifdef CONFIG_NUMA
reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT);
#else
reserve_bootmem(phys, len, BOOTMEM_DEFAULT);
#endif
if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) {
dma_reserve += len / PAGE_SIZE;
set_dma_reserve(dma_reserve);
}
}
int kern_addr_valid(unsigned long addr)
{
unsigned long above = ((long)addr) >> __VIRTUAL_MASK_SHIFT;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
if (above != 0 && above != -1UL)
return 0;
pgd = pgd_offset_k(addr);
if (pgd_none(*pgd))
return 0;
pud = pud_offset(pgd, addr);
if (pud_none(*pud))
return 0;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
return 0;
if (pmd_large(*pmd))
return pfn_valid(pmd_pfn(*pmd));
pte = pte_offset_kernel(pmd, addr);
if (pte_none(*pte))
return 0;
return pfn_valid(pte_pfn(*pte));
}
/*
* A pseudo VMA to allow ptrace access for the vsyscall page. This only
* covers the 64bit vsyscall page now. 32bit has a real VMA now and does
* not need special handling anymore:
*/
static struct vm_area_struct gate_vma = {
.vm_start = VSYSCALL_START,
.vm_end = VSYSCALL_START + (VSYSCALL_MAPPED_PAGES * PAGE_SIZE),
.vm_page_prot = PAGE_READONLY_EXEC,
.vm_flags = VM_READ | VM_EXEC
};
struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
{
#ifdef CONFIG_IA32_EMULATION
if (test_tsk_thread_flag(tsk, TIF_IA32))
return NULL;
#endif
return &gate_vma;
}
int in_gate_area(struct task_struct *task, unsigned long addr)
{
struct vm_area_struct *vma = get_gate_vma(task);
if (!vma)
return 0;
return (addr >= vma->vm_start) && (addr < vma->vm_end);
}
/*
* Use this when you have no reliable task/vma, typically from interrupt
* context. It is less reliable than using the task's vma and may give
* false positives:
*/
int in_gate_area_no_task(unsigned long addr)
{
return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso)
return "[vdso]";
if (vma == &gate_vma)
return "[vsyscall]";
return NULL;
}
#ifdef CONFIG_SPARSEMEM_VMEMMAP
/*
* Initialise the sparsemem vmemmap using huge-pages at the PMD level.
*/
int __meminit
vmemmap_populate(struct page *start_page, unsigned long size, int node)
{
unsigned long addr = (unsigned long)start_page;
unsigned long end = (unsigned long)(start_page + size);
unsigned long next;
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
for (; addr < end; addr = next) {
next = pmd_addr_end(addr, end);
pgd = vmemmap_pgd_populate(addr, node);
if (!pgd)
return -ENOMEM;
pud = vmemmap_pud_populate(pgd, addr, node);
if (!pud)
return -ENOMEM;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd)) {
pte_t entry;
void *p;
p = vmemmap_alloc_block(PMD_SIZE, node);
if (!p)
return -ENOMEM;
entry = pfn_pte(__pa(p) >> PAGE_SHIFT,
PAGE_KERNEL_LARGE);
set_pmd(pmd, __pmd(pte_val(entry)));
printk(KERN_DEBUG " [%lx-%lx] PMD ->%p on node %d\n",
addr, addr + PMD_SIZE - 1, p, node);
} else {
vmemmap_verify((pte_t *)pmd, node, addr, next);
}
}
return 0;
}
#endif