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Commit bf16ae25 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

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

arch/x86/Kconfig.debug

+11 −0
Original line number Diff line number Diff line
@@ -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

arch/x86/mm/init_32.c

+19 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/mm/init_64.c

+20 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/mm/ioremap.c

+29 −0
Original line number Diff line number Diff line
@@ -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;

arch/x86/mm/pat.c

+161 −14
Original line number Diff line number Diff line
@@ -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)

		/* 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;

	}



	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);

}