Commit bf16ae25 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-pat

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-x86-pat:
  generic: add ioremap_wc() interface wrapper
  /dev/mem: make promisc the default
  pat: cleanups
  x86: PAT use reserve free memtype in mmap of /dev/mem
  x86: PAT phys_mem_access_prot_allowed for dev/mem mmap
  x86: PAT avoid aliasing in /dev/mem read/write
  devmem: add range_is_allowed() check to mmap of /dev/mem
  x86: introduce /dev/mem restrictions with a config option
parents 0b79dada 1526a756
......@@ -5,6 +5,17 @@ config TRACE_IRQFLAGS_SUPPORT
source "lib/Kconfig.debug"
config NONPROMISC_DEVMEM
bool "Disable promiscuous /dev/mem"
help
The /dev/mem file by default only allows userspace access to PCI
space and the BIOS code and data regions. This is sufficient for
dosemu and X and all common users of /dev/mem. With this config
option, you allow userspace access to all of memory, including
kernel and userspace memory. Accidental access to this is
obviously disasterous, but specific access can be used by people
debugging the kernel.
config EARLY_PRINTK
bool "Early printk" if EMBEDDED
default y
......
......@@ -227,6 +227,25 @@ static inline int page_kills_ppro(unsigned long pagenr)
return 0;
}
/*
* 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;
}
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
pgprot_t kmap_prot;
......
......@@ -663,6 +663,26 @@ EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid);
#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;
......
......@@ -336,6 +336,35 @@ void iounmap(volatile void __iomem *addr)
}
EXPORT_SYMBOL(iounmap);
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem
* access
*/
void *xlate_dev_mem_ptr(unsigned long phys)
{
void *addr;
unsigned long start = phys & PAGE_MASK;
/* If page is RAM, we can use __va. Otherwise ioremap and unmap. */
if (page_is_ram(start >> PAGE_SHIFT))
return __va(phys);
addr = (void *)ioremap(start, PAGE_SIZE);
if (addr)
addr = (void *)((unsigned long)addr | (phys & ~PAGE_MASK));
return addr;
}
void unxlate_dev_mem_ptr(unsigned long phys, void *addr)
{
if (page_is_ram(phys >> PAGE_SHIFT))
return;
iounmap((void __iomem *)((unsigned long)addr & PAGE_MASK));
return;
}
#ifdef CONFIG_X86_32
int __initdata early_ioremap_debug;
......
......@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/gfp.h>
#include <linux/fs.h>
#include <linux/bootmem.h>
#include <asm/msr.h>
#include <asm/tlbflush.h>
......@@ -21,6 +22,7 @@
#include <asm/cacheflush.h>
#include <asm/fcntl.h>
#include <asm/mtrr.h>
#include <asm/io.h>
int pat_wc_enabled = 1;
......@@ -190,6 +192,21 @@ static int pat_x_mtrr_type(u64 start, u64 end, unsigned long prot,
return 0;
}
/*
* req_type typically has one of the:
* - _PAGE_CACHE_WB
* - _PAGE_CACHE_WC
* - _PAGE_CACHE_UC_MINUS
* - _PAGE_CACHE_UC
*
* req_type will have a special case value '-1', when requester want to inherit
* the memory type from mtrr (if WB), existing PAT, defaulting to UC_MINUS.
*
* If ret_type is NULL, function will return an error if it cannot reserve the
* region with req_type. If ret_type is non-null, function will return
* available type in ret_type in case of no error. In case of any error
* it will return a negative return value.
*/
int reserve_memtype(u64 start, u64 end, unsigned long req_type,
unsigned long *ret_type)
{
......@@ -200,9 +217,14 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
/* Only track when pat_wc_enabled */
if (!pat_wc_enabled) {
if (ret_type)
*ret_type = req_type;
/* This is identical to page table setting without PAT */
if (ret_type) {
if (req_type == -1) {
*ret_type = _PAGE_CACHE_WB;
} else {
*ret_type = req_type;
}
}
return 0;
}
......@@ -214,8 +236,29 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
return 0;
}
req_type &= _PAGE_CACHE_MASK;
err = pat_x_mtrr_type(start, end, req_type, &actual_type);
if (req_type == -1) {
/*
* Special case where caller wants to inherit from mtrr or
* existing pat mapping, defaulting to UC_MINUS in case of
* no match.
*/
u8 mtrr_type = mtrr_type_lookup(start, end);
if (mtrr_type == 0xFE) { /* MTRR match error */
err = -1;
}
if (mtrr_type == MTRR_TYPE_WRBACK) {
req_type = _PAGE_CACHE_WB;
actual_type = _PAGE_CACHE_WB;
} else {
req_type = _PAGE_CACHE_UC_MINUS;
actual_type = _PAGE_CACHE_UC_MINUS;
}
} else {
req_type &= _PAGE_CACHE_MASK;
err = pat_x_mtrr_type(start, end, req_type, &actual_type);
}
if (err) {
if (ret_type)
*ret_type = actual_type;
......@@ -241,7 +284,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
struct memtype *saved_ptr;
if (parse->start >= end) {
printk("New Entry\n");
pr_debug("New Entry\n");
list_add(&new_entry->nd, parse->nd.prev);
new_entry = NULL;
break;
......@@ -343,7 +386,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
break;
}
printk("Overlap at 0x%Lx-0x%Lx\n",
printk(KERN_INFO "Overlap at 0x%Lx-0x%Lx\n",
saved_ptr->start, saved_ptr->end);
/* No conflict. Go ahead and add this new entry */
list_add(&new_entry->nd, &saved_ptr->nd);
......@@ -353,7 +396,7 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
}
if (err) {
printk(
printk(KERN_INFO
"reserve_memtype failed 0x%Lx-0x%Lx, track %s, req %s\n",
start, end, cattr_name(new_entry->type),
cattr_name(req_type));
......@@ -365,16 +408,16 @@ int reserve_memtype(u64 start, u64 end, unsigned long req_type,
if (new_entry) {
/* No conflict. Not yet added to the list. Add to the tail */
list_add_tail(&new_entry->nd, &memtype_list);
printk("New Entry\n");
}
pr_debug("New Entry\n");
}
if (ret_type) {
printk(
pr_debug(
"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s, ret %s\n",
start, end, cattr_name(actual_type),
cattr_name(req_type), cattr_name(*ret_type));
} else {
printk(
pr_debug(
"reserve_memtype added 0x%Lx-0x%Lx, track %s, req %s\n",
start, end, cattr_name(actual_type),
cattr_name(req_type));
......@@ -411,11 +454,115 @@ int free_memtype(u64 start, u64 end)
spin_unlock(&memtype_lock);
if (err) {
printk(KERN_DEBUG "%s:%d freeing invalid memtype %Lx-%Lx\n",
printk(KERN_INFO "%s:%d freeing invalid memtype %Lx-%Lx\n",
current->comm, current->pid, start, end);
}
printk( "free_memtype request 0x%Lx-0x%Lx\n", start, end);
pr_debug("free_memtype request 0x%Lx-0x%Lx\n", start, end);
return err;
}
/*
* /dev/mem mmap interface. The memtype used for mapping varies:
* - Use UC for mappings with O_SYNC flag
* - Without O_SYNC flag, if there is any conflict in reserve_memtype,
* inherit the memtype from existing mapping.
* - Else use UC_MINUS memtype (for backward compatibility with existing
* X drivers.
*/
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
{
return vma_prot;
}
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t *vma_prot)
{
u64 offset = ((u64) pfn) << PAGE_SHIFT;
unsigned long flags = _PAGE_CACHE_UC_MINUS;
unsigned long ret_flags;
int retval;
if (file->f_flags & O_SYNC) {
flags = _PAGE_CACHE_UC;
}
#ifdef CONFIG_X86_32
/*
* On the PPro and successors, the MTRRs are used to set
* memory types for physical addresses outside main memory,
* so blindly setting UC or PWT on those pages is wrong.
* For Pentiums and earlier, the surround logic should disable
* caching for the high addresses through the KEN pin, but
* we maintain the tradition of paranoia in this code.
*/
if (!pat_wc_enabled &&
! ( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability)) &&
(pfn << PAGE_SHIFT) >= __pa(high_memory)) {
flags = _PAGE_CACHE_UC;
}
#endif
/*
* With O_SYNC, we can only take UC mapping. Fail if we cannot.
* Without O_SYNC, we want to get
* - WB for WB-able memory and no other conflicting mappings
* - UC_MINUS for non-WB-able memory with no other conflicting mappings
* - Inherit from confliting mappings otherwise
*/
if (flags != _PAGE_CACHE_UC_MINUS) {
retval = reserve_memtype(offset, offset + size, flags, NULL);
} else {
retval = reserve_memtype(offset, offset + size, -1, &ret_flags);
}
if (retval < 0)
return 0;
flags = ret_flags;
if (pfn <= max_pfn_mapped &&
ioremap_change_attr((unsigned long)__va(offset), size, flags) < 0) {
free_memtype(offset, offset + size);
printk(KERN_INFO
"%s:%d /dev/mem ioremap_change_attr failed %s for %Lx-%Lx\n",
current->comm, current->pid,
cattr_name(flags),
offset, offset + size);
return 0;
}
*vma_prot = __pgprot((pgprot_val(*vma_prot) & ~_PAGE_CACHE_MASK) |
flags);
return 1;
}
void map_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
{
u64 addr = (u64)pfn << PAGE_SHIFT;
unsigned long flags;
unsigned long want_flags = (pgprot_val(vma_prot) & _PAGE_CACHE_MASK);
reserve_memtype(addr, addr + size, want_flags, &flags);
if (flags != want_flags) {
printk(KERN_INFO
"%s:%d /dev/mem expected mapping type %s for %Lx-%Lx, got %s\n",
current->comm, current->pid,
cattr_name(want_flags),
addr, addr + size,
cattr_name(flags));
}
}
void unmap_devmem(unsigned long pfn, unsigned long size, pgprot_t vma_prot)
{
u64 addr = (u64)pfn << PAGE_SHIFT;
free_memtype(addr, addr + size);
}
......@@ -41,36 +41,7 @@
*/
static inline int uncached_access(struct file *file, unsigned long addr)
{
#if defined(__i386__) && !defined(__arch_um__)
/*
* On the PPro and successors, the MTRRs are used to set
* memory types for physical addresses outside main memory,
* so blindly setting PCD or PWT on those pages is wrong.
* For Pentiums and earlier, the surround logic should disable
* caching for the high addresses through the KEN pin, but
* we maintain the tradition of paranoia in this code.
*/
if (file->f_flags & O_SYNC)
return 1;
return !( test_bit(X86_FEATURE_MTRR, boot_cpu_data.x86_capability) ||
test_bit(X86_FEATURE_K6_MTRR, boot_cpu_data.x86_capability) ||
test_bit(X86_FEATURE_CYRIX_ARR, boot_cpu_data.x86_capability) ||
test_bit(X86_FEATURE_CENTAUR_MCR, boot_cpu_data.x86_capability) )
&& addr >= __pa(high_memory);
#elif defined(__x86_64__) && !defined(__arch_um__)
/*
* This is broken because it can generate memory type aliases,
* which can cause cache corruptions
* But it is only available for root and we have to be bug-to-bug
* compatible with i386.
*/
if (file->f_flags & O_SYNC)
return 1;
/* same behaviour as i386. PAT always set to cached and MTRRs control the
caching behaviour.
Hopefully a full PAT implementation will fix that soon. */
return 0;
#elif defined(CONFIG_IA64)
#if defined(CONFIG_IA64)
/*
* On ia64, we ignore O_SYNC because we cannot tolerate memory attribute aliases.
*/
......@@ -108,6 +79,36 @@ static inline int valid_mmap_phys_addr_range(unsigned long pfn, size_t size)
}
#endif
#ifdef CONFIG_NONPROMISC_DEVMEM
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
u64 from = ((u64)pfn) << PAGE_SHIFT;
u64 to = from + size;
u64 cursor = from;
while (cursor < to) {
if (!devmem_is_allowed(pfn)) {
printk(KERN_INFO
"Program %s tried to access /dev/mem between %Lx->%Lx.\n",
current->comm, from, to);
return 0;
}
cursor += PAGE_SIZE;
pfn++;
}
return 1;
}
#else
static inline int range_is_allowed(unsigned long pfn, unsigned long size)
{
return 1;
}
#endif
void __attribute__((weak)) unxlate_dev_mem_ptr(unsigned long phys, void *addr)
{
}
/*
* This funcion reads the *physical* memory. The f_pos points directly to the
* memory location.
......@@ -150,15 +151,25 @@ static ssize_t read_mem(struct file * file, char __user * buf,
sz = min_t(unsigned long, sz, count);
if (!range_is_allowed(p >> PAGE_SHIFT, count))
return -EPERM;
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
if (!ptr)
return -EFAULT;
if (copy_to_user(buf, ptr, sz))
if (copy_to_user(buf, ptr, sz)) {
unxlate_dev_mem_ptr(p, ptr);
return -EFAULT;
}
unxlate_dev_mem_ptr(p, ptr);
buf += sz;
p += sz;
count -= sz;
......@@ -207,20 +218,32 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
sz = min_t(unsigned long, sz, count);
if (!range_is_allowed(p >> PAGE_SHIFT, sz))
return -EPERM;
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
if (!ptr) {
if (written)
break;
return -EFAULT;
}
copied = copy_from_user(ptr, buf, sz);
if (copied) {
written += sz - copied;
unxlate_dev_mem_ptr(p, ptr);
if (written)
break;
return -EFAULT;
}
unxlate_dev_mem_ptr(p, ptr);
buf += sz;
p += sz;
count -= sz;
......@@ -231,6 +254,12 @@ static ssize_t write_mem(struct file * file, const char __user * buf,
return written;
}
int __attribute__((weak)) phys_mem_access_prot_allowed(struct file *file,
unsigned long pfn, unsigned long size, pgprot_t *vma_prot)
{
return 1;
}
#ifndef __HAVE_PHYS_MEM_ACCESS_PROT
static pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot)
......@@ -271,6 +300,35 @@ static inline int private_mapping_ok(struct vm_area_struct *vma)
}
#endif
void __attribute__((weak))
map_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
{
/* nothing. architectures can override. */
}
void __attribute__((weak))
unmap_devmem(unsigned long pfn, unsigned long len, pgprot_t prot)
{
/* nothing. architectures can override. */
}
static void mmap_mem_open(struct vm_area_struct *vma)
{
map_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
static void mmap_mem_close(struct vm_area_struct *vma)
{
unmap_devmem(vma->vm_pgoff, vma->vm_end - vma->vm_start,
vma->vm_page_prot);
}
static struct vm_operations_struct mmap_mem_ops = {
.open = mmap_mem_open,
.close = mmap_mem_close
};
static int mmap_mem(struct file * file, struct vm_area_struct * vma)
{
size_t size = vma->vm_end - vma->vm_start;
......@@ -281,17 +339,28 @@ static int mmap_mem(struct file * file, struct vm_area_struct * vma)
if (!private_mapping_ok(vma))
return -ENOSYS;
if (!range_is_allowed(vma->vm_pgoff, size))
return -EPERM;
if (!phys_mem_access_prot_allowed(file, vma->vm_pgoff, size,
&vma->vm_page_prot))
return -EINVAL;
vma->vm_page_prot = phys_mem_access_prot(file, vma->vm_pgoff,
size,
vma->vm_page_prot);
vma->vm_ops = &mmap_mem_ops;
/* Remap-pfn-range will mark the range VM_IO and VM_RESERVED */
if (remap_pfn_range(vma,
vma->vm_start,
vma->vm_pgoff,
size,
vma->vm_page_prot))
vma->vm_page_prot)) {
unmap_devmem(vma->vm_pgoff, size, vma->vm_page_prot);
return -EAGAIN;
}
return 0;
}
......
......@@ -60,6 +60,10 @@ extern void iowrite32_rep(void __iomem *port, const void *buf, unsigned long cou
extern void __iomem *ioport_map(unsigned long port, unsigned int nr);
extern void ioport_unmap(void __iomem *);
#ifndef ARCH_HAS_IOREMAP_WC
#define ioremap_wc ioremap_nocache
#endif
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
struct pci_dev;
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
......
#ifndef _ASM_X86_IO_H
#define _ASM_X86_IO_H
#define ARCH_HAS_IOREMAP_WC
#ifdef CONFIG_X86_32
......@@ -5,7 +8,12 @@
#else
# include "io_64.h"
#endif
extern void *xlate_dev_mem_ptr(unsigned long phys);
extern void unxlate_dev_mem_ptr(unsigned long phys, void *addr);
extern int ioremap_change_attr(unsigned long vaddr, unsigned long size,
unsigned long prot_val);
extern void __iomem *ioremap_wc(unsigned long offset, unsigned long size);
#endif /* _ASM_X86_IO_H */
......@@ -48,12 +48,6 @@
#include <linux/vmalloc.h>
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem
* access
*/
#define xlate_dev_mem_ptr(p) __va(p)
/*
* Convert a virtual cached pointer to an uncached pointer
*/
......
......@@ -307,12 +307,6 @@ void memset_io(volatile void __iomem *a, int b, size_t c);
extern int iommu_bio_merge;
#define BIO_VMERGE_BOUNDARY iommu_bio_merge
/*
* Convert a physical pointer to a virtual kernel pointer for /dev/mem
* access
*/
#define xlate_dev_mem_ptr(p) __va(p)
/*
* Convert a virtual cached pointer to an uncached pointer
*/
......
......@@ -47,6 +47,7 @@
#ifndef __ASSEMBLY__
extern int page_is_ram(unsigned long pagenr);
extern int devmem_is_allowed(unsigned long pagenr);
extern unsigned long max_pfn_mapped;
......
......@@ -288,6 +288,15 @@ static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
#define canon_pgprot(p) __pgprot(pgprot_val(p) & __supported_pte_mask)
#ifndef __ASSEMBLY__
#define __HAVE_PHYS_MEM_ACCESS_PROT
struct file;
pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t vma_prot);
int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
unsigned long size, pgprot_t *vma_prot);
#endif
#ifdef CONFIG_PARAVIRT
#include <asm/paravirt.h>
#else /* !CONFIG_PARAVIRT */
......
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