From 59ea746337c69f6a5f1bc4d5e8544b3cbf12f801 Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 12 Jun 2008 13:56:40 +0200 Subject: 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/mm/ioremap.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-) (limited to 'arch/x86/mm') 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) -- cgit v1.2.3 From a1bf9631be7332ce0641e299ddafad2d8223100f Mon Sep 17 00:00:00 2001 From: Jiri Slaby Date: Thu, 12 Jun 2008 13:56:40 +0200 Subject: x86, MM: virtual address debug, v2 I've removed the test from phys_to_nid and made a function from __phys_addr only when the debugging is enabled (on x86_32). Signed-off-by: Jiri Slaby Cc: tglx@linutronix.de Cc: hpa@zytor.com Cc: Mike Travis Cc: Nick Piggin Cc: Cc: linux-mm@kvack.org Cc: Jiri Slaby Cc: Andi Kleen Signed-off-by: Ingo Molnar --- arch/x86/mm/ioremap.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/ioremap.c b/arch/x86/mm/ioremap.c index a78ffef62a2..9dd3cb90597 100644 --- a/arch/x86/mm/ioremap.c +++ b/arch/x86/mm/ioremap.c @@ -51,6 +51,7 @@ static inline int phys_addr_valid(unsigned long addr) return 1; } +#ifdef CONFIG_DEBUG_VIRTUAL unsigned long __phys_addr(unsigned long x) { /* VMALLOC_* aren't constants; not available at the boot time */ @@ -59,6 +60,7 @@ unsigned long __phys_addr(unsigned long x) return x - PAGE_OFFSET; } EXPORT_SYMBOL(__phys_addr); +#endif #endif -- cgit v1.2.3 From cc643d4687533345fd8ebcba836f9ee25df7c458 Mon Sep 17 00:00:00 2001 From: Jan Beulich Date: Fri, 29 Aug 2008 12:53:45 +0100 Subject: x86: adjust vmalloc_sync_all() for Xen (2nd try) Since the fourth PDPT entry cannot be shared under Xen, vmalloc_sync_all() must iterate over pmd-s rather than pgd-s here. Luckily, the code isn't used for native PAE (SHARED_KERNEL_PMD is 1) and the change is benign to non-PAE. Also do a little more cleanup in that function. Signed-off-by: Jan Beulich Signed-off-by: Ingo Molnar Cc: Jeremy Fitzhardinge --- arch/x86/mm/fault.c | 14 ++++++-------- 1 file changed, 6 insertions(+), 8 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 455f3fe67b4..356ed2dec3a 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -915,15 +915,15 @@ LIST_HEAD(pgd_list); void vmalloc_sync_all(void) { -#ifdef CONFIG_X86_32 - unsigned long start = VMALLOC_START & PGDIR_MASK; unsigned long address; +#ifdef CONFIG_X86_32 if (SHARED_KERNEL_PMD) return; - BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK); - for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) { + for (address = VMALLOC_START & PMD_MASK; + address >= TASK_SIZE && address < FIXADDR_TOP; + address += PMD_SIZE) { unsigned long flags; struct page *page; @@ -936,10 +936,8 @@ void vmalloc_sync_all(void) spin_unlock_irqrestore(&pgd_lock, flags); } #else /* CONFIG_X86_64 */ - unsigned long start = VMALLOC_START & PGDIR_MASK; - unsigned long address; - - for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) { + for (address = VMALLOC_START & PGDIR_MASK; address <= VMALLOC_END; + address += PGDIR_SIZE) { const pgd_t *pgd_ref = pgd_offset_k(address); unsigned long flags; struct page *page; -- cgit v1.2.3 From 5394f80f92642c61fc2a95385be85f2fdcfb5adb Mon Sep 17 00:00:00 2001 From: Jeremy Fitzhardinge Date: Sun, 7 Sep 2008 01:51:32 -0700 Subject: x86: check for and defend against BIOS memory corruption Some BIOSes have been observed to corrupt memory in the low 64k. This change: - Reserves all memory which does not have to be in that area, to prevent it from being used as general memory by the kernel. Things like the SMP trampoline are still in the memory, however. - Clears the reserved memory so we can observe changes to it. - Adds a function check_for_bios_corruption() which checks and reports on memory becoming unexpectedly non-zero. Currently it's called in the x86 fault handler, and the powermanagement debug output. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 455f3fe67b4..5140bdf0302 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -848,6 +848,8 @@ no_context: * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */ + check_for_bios_corruption(); + #ifdef CONFIG_X86_32 bust_spinlocks(1); #else -- cgit v1.2.3 From bb577f980ef35e2b0d00aeed566724e5032aa5eb Mon Sep 17 00:00:00 2001 From: Hugh Dickins Date: Sun, 7 Sep 2008 01:51:33 -0700 Subject: x86: add periodic corruption check Perodically check for corruption in low phusical memory. Don't bother checking at fault time, since it won't show anything useful. Signed-off-by: Hugh Dickins Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Ingo Molnar --- arch/x86/mm/fault.c | 2 -- arch/x86/mm/init_32.c | 2 ++ arch/x86/mm/init_64.c | 2 ++ 3 files changed, 4 insertions(+), 2 deletions(-) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 5140bdf0302..455f3fe67b4 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -848,8 +848,6 @@ no_context: * Oops. The kernel tried to access some bad page. We'll have to * terminate things with extreme prejudice. */ - check_for_bios_corruption(); - #ifdef CONFIG_X86_32 bust_spinlocks(1); #else diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index d37f29376b0..657a16ad61b 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -907,6 +907,8 @@ void __init mem_init(void) int codesize, reservedpages, datasize, initsize; int tmp; + start_periodic_check_for_corruption(); + #ifdef CONFIG_FLATMEM BUG_ON(!mem_map); #endif diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index d3746efb060..f4db5276fa2 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -769,6 +769,8 @@ void __init mem_init(void) { long codesize, reservedpages, datasize, initsize; + start_periodic_check_for_corruption(); + pci_iommu_alloc(); /* clear_bss() already clear the empty_zero_page */ -- cgit v1.2.3 From 46eaa6702016e3ac9a188172a2c309d6ca1be1cd Mon Sep 17 00:00:00 2001 From: Ingo Molnar Date: Sun, 12 Oct 2008 15:06:29 +0200 Subject: x86: memory corruption check - cleanup Move the prototypes from the generic kernel.h header to the more appropriate include/asm-x86/bios_ebda.h header file. Also, remove the check from the power management code - this is a pure x86 matter for now. Signed-off-by: Ingo Molnar --- arch/x86/mm/init_32.c | 1 + arch/x86/mm/init_64.c | 1 + 2 files changed, 2 insertions(+) (limited to 'arch/x86/mm') diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c index 7e05462ffb1..bbe044dbe01 100644 --- a/arch/x86/mm/init_32.c +++ b/arch/x86/mm/init_32.c @@ -31,6 +31,7 @@ #include #include +#include #include #include #include diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index d84d3e91d34..3e10054c573 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -31,6 +31,7 @@ #include #include +#include #include #include #include -- cgit v1.2.3