From 4de0d4a6d173351b023ab2855c3d331146a418e5 Mon Sep 17 00:00:00 2001 From: "Huang, Ying" Date: Wed, 13 Feb 2008 17:22:41 +0800 Subject: [PATCH] x86: EFI runtime code mapping enhancement 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 Signed-off-by: Ingo Molnar --- arch/x86/kernel/efi.c | 6 ++---- arch/x86/kernel/efi_64.c | 32 +++++++++++++------------------- 2 files changed, 15 insertions(+), 23 deletions(-) diff --git a/arch/x86/kernel/efi.c b/arch/x86/kernel/efi.c index b4d523276f40..cbdf9bacc575 100644 --- a/arch/x86/kernel/efi.c +++ b/arch/x86/kernel/efi.c @@ -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; } diff --git a/arch/x86/kernel/efi_64.c b/arch/x86/kernel/efi_64.c index 09d5c2330934..d143a1e76b30 100644 --- a/arch/x86/kernel/efi_64.c +++ b/arch/x86/kernel/efi_64.c @@ -35,6 +35,7 @@ #include #include #include +#include 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; - - 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; - } + unsigned long num_pages; + + 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) -- 2.20.1