Commit a2172e25 authored by Huang, Ying's avatar Huang, Ying Committed by Ingo Molnar
Browse files

x86: fix some bugs about EFI runtime code mapping 



This patch fixes some bugs of making EFI runtime code executable.

- Use change_page_attr in i386 too. Because the runtime code may be
  mapped not through ioremap.

- If there is no _PAGE_NX in __supported_pte_mask, the change_page_attr
  is not called.

- Make efi_ioremap map pages as PAGE_KERNEL_EXEC_NOCACHE, because EFI runtime
  code may be mapped through efi_ioremap.

Signed-off-by: default avatarHuang Ying <ying.huang@intel.com>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent cd582896

arch/x86/kernel/efi.c

+30 −5
Original line number Diff line number Diff line
@@ -40,6 +40,8 @@ 
#include <asm/setup.h>

#include <asm/efi.h>

#include <asm/time.h>

#include <asm/cacheflush.h>

#include <asm/tlbflush.h>



#define EFI_DEBUG	1

#define PFX 		"EFI: "
@@ -379,6 +381,32 @@ void __init efi_init(void) 
#endif

}



#if defined(CONFIG_X86_64) || defined(CONFIG_X86_PAE)

static void __init runtime_code_page_mkexec(void)

{

	efi_memory_desc_t *md;

	unsigned long end;

	void *p;



	if (!(__supported_pte_mask & _PAGE_NX))

		return;



	/* Make EFI runtime service code area executable */

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {

		md = p;

		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);

		if (md->type == EFI_RUNTIME_SERVICES_CODE &&

		    (end >> PAGE_SHIFT) <= end_pfn_map)

			change_page_attr_addr(md->virt_addr,

					      md->num_pages,

					      PAGE_KERNEL_EXEC_NOCACHE);

	}

	__flush_tlb_all();

}

#else

static inline void __init runtime_code_page_mkexec(void) { }

#endif



/*

 * This function will switch the EFI runtime services to virtual mode.

 * Essentially, look through the EFI memmap and map every region that
@@ -399,9 +427,9 @@ void __init efi_enter_virtual_mode(void) 
		md = p;

		if (!(md->attribute & EFI_MEMORY_RUNTIME))

			continue;

		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);

		if ((md->attribute & EFI_MEMORY_WB) &&

		    (((md->phys_addr + (md->num_pages<<EFI_PAGE_SHIFT)) >>

		      PAGE_SHIFT) < end_pfn_map))

		    ((end >> PAGE_SHIFT) <= end_pfn_map))

			md->virt_addr = (unsigned long)__va(md->phys_addr);

		else

			md->virt_addr = (unsigned long)
@@ -410,7 +438,6 @@ void __init efi_enter_virtual_mode(void) 
		if (!md->virt_addr)

			printk(KERN_ERR PFX "ioremap of 0x%llX failed!\n",

			       (unsigned long long)md->phys_addr);

		end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);

		if ((md->phys_addr <= (unsigned long)efi_phys.systab) &&

		    ((unsigned long)efi_phys.systab < end))

			efi.systab = (efi_system_table_t *)(unsigned long)
@@ -448,9 +475,7 @@ void __init efi_enter_virtual_mode(void) 
	efi.get_next_high_mono_count = virt_efi_get_next_high_mono_count;

	efi.reset_system = virt_efi_reset_system;

	efi.set_virtual_address_map = virt_efi_set_virtual_address_map;

#ifdef CONFIG_X86_64

	runtime_code_page_mkexec();

#endif

}



/*

arch/x86/kernel/efi_64.c

+6 −20
Original line number Diff line number Diff line
@@ -33,7 +33,6 @@ 
#include <asm/e820.h>

#include <asm/pgtable.h>

#include <asm/tlbflush.h>

#include <asm/cacheflush.h>

#include <asm/proto.h>

#include <asm/efi.h>
@@ -55,7 +54,7 @@ static void __init early_mapping_set_exec(unsigned long start, 
		else

			set_pte(kpte, __pte((pte_val(*kpte) | _PAGE_NX) & \

					    __supported_pte_mask));

		if (pte_huge(*kpte))

		if (level == 4)

			start = (start + PMD_SIZE) & PMD_MASK;

		else

			start = (start + PAGE_SIZE) & PAGE_MASK;
@@ -67,6 +66,9 @@ static void __init early_runtime_code_mapping_set_exec(int executable) 
	efi_memory_desc_t *md;

	void *p;



	if (!(__supported_pte_mask & _PAGE_NX))

		return;



	/* Make EFI runtime service code area executable */

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {

		md = p;
@@ -116,22 +118,6 @@ void __init efi_reserve_bootmem(void) 
				memmap.nr_map * memmap.desc_size);

}



void __init runtime_code_page_mkexec(void)

{

	efi_memory_desc_t *md;

	void *p;



	/* Make EFI runtime service code area executable */

	for (p = memmap.map; p < memmap.map_end; p += memmap.desc_size) {

		md = p;

		if (md->type == EFI_RUNTIME_SERVICES_CODE)

			change_page_attr_addr(md->virt_addr,

					      md->num_pages,

					      PAGE_KERNEL_EXEC);

	}

	__flush_tlb_all();

}



void __iomem * __init efi_ioremap(unsigned long offset,

				  unsigned long size)

{
@@ -146,8 +132,8 @@ void __iomem * __init efi_ioremap(unsigned long offset, 
		return NULL;



	for (i = 0; i < pages; i++) {

		set_fixmap_nocache(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,

				   offset);

		__set_fixmap(FIX_EFI_IO_MAP_FIRST_PAGE - pages_mapped,

			     offset, PAGE_KERNEL_EXEC_NOCACHE);

		offset += PAGE_SIZE;

		pages_mapped++;

	}

include/asm-x86/efi.h

+0 −1
Original line number Diff line number Diff line
@@ -95,6 +95,5 @@ extern void *efi_ioremap(unsigned long offset, unsigned long size); 
extern void efi_reserve_bootmem(void);

extern void efi_call_phys_prelog(void);

extern void efi_call_phys_epilog(void);

extern void runtime_code_page_mkexec(void);



#endif

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