From 59ea746337c69f6a5f1bc4d5e8544b3cbf12f801 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 12 Jun 2008 13:56:40 +0200 Subject: [PATCH] MM: virtual address debug Add some (configurable) expensive sanity checking to catch wrong address translations on x86. - create linux/mmdebug.h file to be able include this file in asm headers to not get unsolvable loops in header files - __phys_addr on x86_32 became a function in ioremap.c since PAGE_OFFSET, is_vmalloc_addr and VMALLOC_* non-constasts are undefined if declared in page_32.h - add __phys_addr_const for initializing doublefault_tss.__cr3 Tested on 386, 386pae, x86_64 and x86_64 numa=fake=2. Contains Andi's enable numa virtual address debug patch. Signed-off-by: Jiri Slaby Cc: Andi Kleen Signed-off-by: Ingo Molnar --- arch/x86/kernel/doublefault_32.c | 2 +- arch/x86/mm/ioremap.c | 31 ++++++++++++++++++++++++------- include/asm-x86/mmzone_64.h | 2 +- include/asm-x86/page_32.h | 3 ++- include/linux/mm.h | 7 +------ include/linux/mmdebug.h | 18 ++++++++++++++++++ lib/Kconfig.debug | 9 +++++++++ mm/vmalloc.c | 5 +++++ 8 files changed, 61 insertions(+), 16 deletions(-) create mode 100644 include/linux/mmdebug.h diff --git a/arch/x86/kernel/doublefault_32.c b/arch/x86/kernel/doublefault_32.c index a47798b59f0..395acb12b0d 100644 --- a/arch/x86/kernel/doublefault_32.c +++ b/arch/x86/kernel/doublefault_32.c @@ -66,6 +66,6 @@ struct tss_struct doublefault_tss __cacheline_aligned = { .ds = __USER_DS, .fs = __KERNEL_PERCPU, - .__cr3 = __pa(swapper_pg_dir) + .__cr3 = __phys_addr_const((unsigned long)swapper_pg_dir) } }; diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index 2b2bb3f9b68..a78ffef62a2 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -23,18 +23,26 @@ #ifdef CONFIG_X86_64 -unsigned long __phys_addr(unsigned long x) +static inline int phys_addr_valid(unsigned long addr) { - if (x >= __START_KERNEL_map) - return x - __START_KERNEL_map + phys_base; - return x - PAGE_OFFSET; + return addr < (1UL << boot_cpu_data.x86_phys_bits); } -EXPORT_SYMBOL(__phys_addr); -static inline int phys_addr_valid(unsigned long addr) +unsigned long __phys_addr(unsigned long x) { - return addr < (1UL << boot_cpu_data.x86_phys_bits); + if (x >= __START_KERNEL_map) { + x -= __START_KERNEL_map; + VIRTUAL_BUG_ON(x >= KERNEL_IMAGE_SIZE); + x += phys_base; + } else { + VIRTUAL_BUG_ON(x < PAGE_OFFSET); + x -= PAGE_OFFSET; + VIRTUAL_BUG_ON(system_state == SYSTEM_BOOTING ? x > MAXMEM : + !phys_addr_valid(x)); + } + return x; } +EXPORT_SYMBOL(__phys_addr); #else @@ -43,6 +51,15 @@ static inline int phys_addr_valid(unsigned long addr) return 1; } +unsigned long __phys_addr(unsigned long x) +{ + /* VMALLOC_* aren't constants; not available at the boot time */ + VIRTUAL_BUG_ON(x < PAGE_OFFSET || (system_state != SYSTEM_BOOTING && + is_vmalloc_addr((void *)x))); + return x - PAGE_OFFSET; +} +EXPORT_SYMBOL(__phys_addr); + #endif int page_is_ram(unsigned long pagenr) diff --git a/include/asm-x86/mmzone_64.h b/include/asm-x86/mmzone_64.h index 594bd0dc1d0..facde3e5314 100644 --- a/include/asm-x86/mmzone_64.h +++ b/include/asm-x86/mmzone_64.h @@ -7,7 +7,7 @@ #ifdef CONFIG_NUMA -#define VIRTUAL_BUG_ON(x) +#include #include diff --git a/include/asm-x86/page_32.h b/include/asm-x86/page_32.h index 424e82f8ae2..9159bfb9dcf 100644 --- a/include/asm-x86/page_32.h +++ b/include/asm-x86/page_32.h @@ -64,7 +64,8 @@ typedef struct page *pgtable_t; #endif #ifndef __ASSEMBLY__ -#define __phys_addr(x) ((x) - PAGE_OFFSET) +#define __phys_addr_const(x) ((x) - PAGE_OFFSET) +extern unsigned long __phys_addr(unsigned long); #define __phys_reloc_hide(x) RELOC_HIDE((x), 0) #ifdef CONFIG_FLATMEM diff --git a/include/linux/mm.h b/include/linux/mm.h index 586a943cab0..3414a8813e9 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -7,6 +7,7 @@ #include #include +#include #include #include #include @@ -210,12 +211,6 @@ struct inode; */ #include -#ifdef CONFIG_DEBUG_VM -#define VM_BUG_ON(cond) BUG_ON(cond) -#else -#define VM_BUG_ON(condition) do { } while(0) -#endif - /* * Methods to modify the page usage count. * diff --git a/include/linux/mmdebug.h b/include/linux/mmdebug.h new file mode 100644 index 00000000000..860ed1a71bb --- /dev/null +++ b/include/linux/mmdebug.h @@ -0,0 +1,18 @@ +#ifndef LINUX_MM_DEBUG_H +#define LINUX_MM_DEBUG_H 1 + +#include + +#ifdef CONFIG_DEBUG_VM +#define VM_BUG_ON(cond) BUG_ON(cond) +#else +#define VM_BUG_ON(cond) do { } while(0) +#endif + +#ifdef CONFIG_DEBUG_VIRTUAL +#define VIRTUAL_BUG_ON(cond) BUG_ON(cond) +#else +#define VIRTUAL_BUG_ON(cond) do { } while(0) +#endif + +#endif diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug index d2099f41aa1..9d9dc0ddf13 100644 --- a/lib/Kconfig.debug +++ b/lib/Kconfig.debug @@ -469,6 +469,15 @@ config DEBUG_VM If unsure, say N. +config DEBUG_VIRTUAL + bool "Debug VM translations" + depends on DEBUG_KERNEL && X86 + help + Enable some costly sanity checks in virtual to page code. This can + catch mistakes with virt_to_page() and friends. + + If unsure, say N. + config DEBUG_WRITECOUNT bool "Debug filesystem writers count" depends on DEBUG_KERNEL diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 6e45b0f3d12..dc41e9c8ca6 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -180,6 +180,11 @@ struct page *vmalloc_to_page(const void *vmalloc_addr) pmd_t *pmd; pte_t *ptep, pte; + /* XXX we might need to change this if we add VIRTUAL_BUG_ON for + * architectures that do not vmalloc module space */ + VIRTUAL_BUG_ON(!is_vmalloc_addr(vmalloc_addr) && + !is_module_address(addr)); + if (!pgd_none(*pgd)) { pud = pud_offset(pgd, addr); if (!pud_none(*pud)) { -- 2.41.1