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x86: EFI runtime code mapping enhancement

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This patch enhances EFI runtime code memory mapping as following:

- Move __supported_pte_mask & _PAGE_NX checking before invoking
  runtime_code_page_mkexec(). This makes it possible for compiler to
  eliminate runtime_code_page_mkexec() on machine without NX support.

- Use set_memory_x/nx in early_mapping_set_exec(). This eliminates the
  duplicated implementation.

This patch has been tested on Intel x86_64 platform with EFI64/32
firmware.

Signed-off-by: Huang Ying <ying.huang@intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
Huang, Ying 2008-02-13 17:22:41 +08:00 committed by Ingo Molnar
parent e85f20518b
commit 4de0d4a6d1
2 changed files with 14 additions and 22 deletions
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6
arch/x86/kernel/efi.c
View File

@ -384,9 +384,6 @@ static void __init runtime_code_page_mkexec(void)
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;
@ -476,7 +473,8 @@ 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;
runtime_code_page_mkexec();
if (__supported_pte_mask & _PAGE_NX)
runtime_code_page_mkexec();
early_iounmap(memmap.map, memmap.nr_map * memmap.desc_size);
memmap.map = NULL;
}

30
arch/x86/kernel/efi_64.c
View File

@ -35,6 +35,7 @@
#include <asm/tlbflush.h>
#include <asm/proto.h>
#include <asm/efi.h>
#include <asm/cacheflush.h>
static pgd_t save_pgd __initdata;
static unsigned long efi_flags __initdata;
@ -43,22 +44,15 @@ static void __init early_mapping_set_exec(unsigned long start,
unsigned long end,
int executable)
{
pte_t *kpte;
unsigned int level;
unsigned long num_pages;
while (start < end) {
kpte = lookup_address((unsigned long)__va(start), &level);
BUG_ON(!kpte);
if (executable)
set_pte(kpte, pte_mkexec(*kpte));
else
set_pte(kpte, __pte((pte_val(*kpte) | _PAGE_NX) & \
__supported_pte_mask));
if (level == PG_LEVEL_4K)
start = (start + PAGE_SIZE) & PAGE_MASK;
else
start = (start + PMD_SIZE) & PMD_MASK;
}
start &= PMD_MASK;
end = (end + PMD_SIZE - 1) & PMD_MASK;
num_pages = (end - start) >> PAGE_SHIFT;
if (executable)
set_memory_x((unsigned long)__va(start), num_pages);
else
set_memory_nx((unsigned long)__va(start), num_pages);
}
static void __init early_runtime_code_mapping_set_exec(int executable)
@ -74,7 +68,7 @@ static void __init early_runtime_code_mapping_set_exec(int executable)
md = p;
if (md->type == EFI_RUNTIME_SERVICES_CODE) {
unsigned long end;
end = md->phys_addr + (md->num_pages << PAGE_SHIFT);
end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT);
early_mapping_set_exec(md->phys_addr, end, executable);
}
}
@ -84,8 +78,8 @@ void __init efi_call_phys_prelog(void)
{
unsigned long vaddress;
local_irq_save(efi_flags);
early_runtime_code_mapping_set_exec(1);
local_irq_save(efi_flags);
vaddress = (unsigned long)__va(0x0UL);
save_pgd = *pgd_offset_k(0x0UL);
set_pgd(pgd_offset_k(0x0UL), *pgd_offset_k(vaddress));
@ -98,9 +92,9 @@ void __init efi_call_phys_epilog(void)
* After the lock is released, the original page table is restored.
*/
set_pgd(pgd_offset_k(0x0UL), save_pgd);
early_runtime_code_mapping_set_exec(0);
__flush_tlb_all();
local_irq_restore(efi_flags);
early_runtime_code_mapping_set_exec(0);
}
void __init efi_reserve_bootmem(void)