From 3ec96783e3c1d21bf9a1fa3f238f8354c92827f6 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 25 Apr 2008 18:25:25 +0200 Subject: [PATCH 1/6] x86: make clear_fixmap() available on 64-bit as well Signed-off-by: Ingo Molnar --- include/asm-x86/fixmap.h | 8 ++++++++ include/asm-x86/fixmap_32.h | 7 ++----- include/asm-x86/fixmap_64.h | 4 ++-- 3 files changed, 12 insertions(+), 7 deletions(-) diff --git a/include/asm-x86/fixmap.h b/include/asm-x86/fixmap.h index 382eb271a892..5bd206973dca 100644 --- a/include/asm-x86/fixmap.h +++ b/include/asm-x86/fixmap.h @@ -1,5 +1,13 @@ +#ifndef _ASM_FIXMAP_H +#define _ASM_FIXMAP_H + #ifdef CONFIG_X86_32 # include "fixmap_32.h" #else # include "fixmap_64.h" #endif + +#define clear_fixmap(idx) \ + __set_fixmap(idx, 0, __pgprot(0)) + +#endif diff --git a/include/asm-x86/fixmap_32.h b/include/asm-x86/fixmap_32.h index eb1665125c44..4b96148e90c1 100644 --- a/include/asm-x86/fixmap_32.h +++ b/include/asm-x86/fixmap_32.h @@ -10,8 +10,8 @@ * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 */ -#ifndef _ASM_FIXMAP_H -#define _ASM_FIXMAP_H +#ifndef _ASM_FIXMAP_32_H +#define _ASM_FIXMAP_32_H /* used by vmalloc.c, vsyscall.lds.S. @@ -121,9 +121,6 @@ extern void reserve_top_address(unsigned long reserve); #define set_fixmap_nocache(idx, phys) \ __set_fixmap(idx, phys, PAGE_KERNEL_NOCACHE) -#define clear_fixmap(idx) \ - __set_fixmap(idx, 0, __pgprot(0)) - #define FIXADDR_TOP ((unsigned long)__FIXADDR_TOP) #define __FIXADDR_SIZE (__end_of_permanent_fixed_addresses << PAGE_SHIFT) diff --git a/include/asm-x86/fixmap_64.h b/include/asm-x86/fixmap_64.h index f3d76858c0e6..355d26a75a82 100644 --- a/include/asm-x86/fixmap_64.h +++ b/include/asm-x86/fixmap_64.h @@ -8,8 +8,8 @@ * Copyright (C) 1998 Ingo Molnar */ -#ifndef _ASM_FIXMAP_H -#define _ASM_FIXMAP_H +#ifndef _ASM_FIXMAP_64_H +#define _ASM_FIXMAP_64_H #include #include From 82a355f5a2fdc203e5a32626d667ec43fc76b8b1 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 25 Apr 2008 18:28:21 +0200 Subject: [PATCH 2/6] x86: make __set_fixmap() non-init Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 1ff7906a9a4d..7a81dd020693 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -135,7 +135,7 @@ static __init void *spp_getpage(void) return ptr; } -static __init void +static void set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot) { pgd_t *pgd; @@ -214,8 +214,7 @@ void __init cleanup_highmap(void) } /* NOTE: this is meant to be run only at boot */ -void __init -__set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) +void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot) { unsigned long address = __fix_to_virt(idx); From 70c9f590ffc3f959cc81c1a3cecb6b8133caf35d Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 25 Apr 2008 18:05:57 +0200 Subject: [PATCH 3/6] x86: remove set_fixmap() warning set_fixmap()+clear_fixmap() is safe. Signed-off-by: Ingo Molnar --- arch/x86/mm/init_64.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index 7a81dd020693..b798e7b92b17 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -173,7 +173,7 @@ set_pte_phys(unsigned long vaddr, unsigned long phys, pgprot_t prot) new_pte = pfn_pte(phys >> PAGE_SHIFT, prot); pte = pte_offset_kernel(pmd, vaddr); - if (!pte_none(*pte) && + if (!pte_none(*pte) && pte_val(new_pte) && pte_val(*pte) != (pte_val(new_pte) & __supported_pte_mask)) pte_ERROR(*pte); set_pte(pte, new_pte); From 8b132ecbcfea8b1b556a832df7290379df79ad79 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Mon, 28 Apr 2008 02:51:23 +0200 Subject: [PATCH 4/6] x86: fix text_poke() kernel_text_address returns true even for modules which is not wanted in text_poke. Use core_kernel_text instead. This is a regression introduced in e587cadd8f47e202a30712e2906a65a0606d5865 which caused occasionaly crashes after suspend/resume. Signed-off-by: Jiri Slaby CC: Mathieu Desnoyers CC: Andi Kleen CC: pageexec@freemail.hu CC: H. Peter Anvin CC: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/kernel/alternative.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index df4099dc1c68..7ab3a9774763 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -515,7 +515,7 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len) BUG_ON(len > sizeof(long)); BUG_ON((((long)addr + len - 1) & ~(sizeof(long) - 1)) - ((long)addr & ~(sizeof(long) - 1))); - if (kernel_text_address((unsigned long)addr)) { + if (core_kernel_text((unsigned long)addr)) { struct page *pages[2] = { virt_to_page(addr), virt_to_page(addr + PAGE_SIZE) }; if (!pages[1]) From b7b66baa8bc3f8e0cda6576e31e9bde09382565d Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Thu, 24 Apr 2008 11:03:33 -0400 Subject: [PATCH 5/6] x86: clean up text_poke() Clean up the codepath, remove alignment restrictions and do sanity checking of the end result, to make sure we patched the right site. Signed-off-by: Mathieu Desnoyers Signed-off-by: Ingo Molnar --- arch/x86/kernel/alternative.c | 38 +++++++++++++++++------------------ 1 file changed, 18 insertions(+), 20 deletions(-) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 7ab3a9774763..60299f61843f 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -511,31 +511,29 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len) unsigned long flags; char *vaddr; int nr_pages = 2; + struct page *pages[2]; + int i; - BUG_ON(len > sizeof(long)); - BUG_ON((((long)addr + len - 1) & ~(sizeof(long) - 1)) - - ((long)addr & ~(sizeof(long) - 1))); - if (core_kernel_text((unsigned long)addr)) { - struct page *pages[2] = { virt_to_page(addr), - virt_to_page(addr + PAGE_SIZE) }; - if (!pages[1]) - nr_pages = 1; - vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL); - BUG_ON(!vaddr); - local_irq_save(flags); - memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len); - local_irq_restore(flags); - vunmap(vaddr); + if (!core_kernel_text((unsigned long)addr)) { + pages[0] = vmalloc_to_page(addr); + pages[1] = vmalloc_to_page(addr + PAGE_SIZE); } else { - /* - * modules are in vmalloc'ed memory, always writable. - */ - local_irq_save(flags); - memcpy(addr, opcode, len); - local_irq_restore(flags); + pages[0] = virt_to_page(addr); + pages[1] = virt_to_page(addr + PAGE_SIZE); } + BUG_ON(!pages[0]); + if (!pages[1]) + nr_pages = 1; + vaddr = vmap(pages, nr_pages, VM_MAP, PAGE_KERNEL); + BUG_ON(!vaddr); + local_irq_save(flags); + memcpy(&vaddr[(unsigned long)addr & ~PAGE_MASK], opcode, len); + local_irq_restore(flags); + vunmap(vaddr); sync_core(); /* Could also do a CLFLUSH here to speed up CPU recovery; but that causes hangs on some VIA CPUs. */ + for (i = 0; i < len; i++) + BUG_ON(((char *)addr)[i] != ((char *)opcode)[i]); return addr; } From 00c6b2d5d7b2414bd46c620d6a8c37fa7a716f29 Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Fri, 25 Apr 2008 17:07:03 +0200 Subject: [PATCH 6/6] x86: harden kernel code patching Signed-off-by: Ingo Molnar --- arch/x86/kernel/alternative.c | 1 + 1 file changed, 1 insertion(+) diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index 60299f61843f..65c7857a90dd 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -519,6 +519,7 @@ void *__kprobes text_poke(void *addr, const void *opcode, size_t len) pages[1] = vmalloc_to_page(addr + PAGE_SIZE); } else { pages[0] = virt_to_page(addr); + WARN_ON(!PageReserved(pages[0])); pages[1] = virt_to_page(addr + PAGE_SIZE); } BUG_ON(!pages[0]);