Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 2 | * Copyright (C) 1995 Linus Torvalds |
| 3 | * Copyright (C) 2001,2002 Andi Kleen, SuSE Labs. |
| 4 | */ |
| 5 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 6 | #include <linux/signal.h> |
| 7 | #include <linux/sched.h> |
| 8 | #include <linux/kernel.h> |
| 9 | #include <linux/errno.h> |
| 10 | #include <linux/string.h> |
| 11 | #include <linux/types.h> |
| 12 | #include <linux/ptrace.h> |
| 13 | #include <linux/mman.h> |
| 14 | #include <linux/mm.h> |
| 15 | #include <linux/smp.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 16 | #include <linux/interrupt.h> |
| 17 | #include <linux/init.h> |
| 18 | #include <linux/tty.h> |
| 19 | #include <linux/vt_kern.h> /* For unblank_screen() */ |
| 20 | #include <linux/compiler.h> |
Harvey Harrison | c61e211 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 21 | #include <linux/highmem.h> |
| 22 | #include <linux/bootmem.h> /* for max_low_pfn */ |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 23 | #include <linux/vmalloc.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 24 | #include <linux/module.h> |
Prasanna S Panchamukhi | 0f2fbdc | 2005-09-06 15:19:28 -0700 | [diff] [blame] | 25 | #include <linux/kprobes.h> |
Andi Kleen | ab2bf0c | 2006-12-07 02:14:06 +0100 | [diff] [blame] | 26 | #include <linux/uaccess.h> |
Christoph Hellwig | 1eeb66a | 2007-05-08 00:27:03 -0700 | [diff] [blame] | 27 | #include <linux/kdebug.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 28 | |
| 29 | #include <asm/system.h> |
Harvey Harrison | c61e211 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 30 | #include <asm/desc.h> |
| 31 | #include <asm/segment.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | #include <asm/pgalloc.h> |
| 33 | #include <asm/smp.h> |
| 34 | #include <asm/tlbflush.h> |
| 35 | #include <asm/proto.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 36 | #include <asm-generic/sections.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 37 | |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 38 | /* |
| 39 | * Page fault error code bits |
| 40 | * bit 0 == 0 means no page found, 1 means protection fault |
| 41 | * bit 1 == 0 means read, 1 means write |
| 42 | * bit 2 == 0 means kernel, 1 means user-mode |
| 43 | * bit 3 == 1 means use of reserved bit detected |
| 44 | * bit 4 == 1 means fault was an instruction fetch |
| 45 | */ |
Ingo Molnar | 8a19da7 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 46 | #define PF_PROT (1<<0) |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 47 | #define PF_WRITE (1<<1) |
Ingo Molnar | 8a19da7 | 2008-01-30 13:32:53 +0100 | [diff] [blame] | 48 | #define PF_USER (1<<2) |
| 49 | #define PF_RSVD (1<<3) |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 50 | #define PF_INSTR (1<<4) |
| 51 | |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 52 | static inline int notify_page_fault(struct pt_regs *regs) |
Anil S Keshavamurthy | 1bd858a | 2006-06-26 00:25:25 -0700 | [diff] [blame] | 53 | { |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 54 | #ifdef CONFIG_KPROBES |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 55 | int ret = 0; |
Anil S Keshavamurthy | 1bd858a | 2006-06-26 00:25:25 -0700 | [diff] [blame] | 56 | |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 57 | /* kprobe_running() needs smp_processor_id() */ |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 58 | #ifdef CONFIG_X86_32 |
| 59 | if (!user_mode_vm(regs)) { |
| 60 | #else |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 61 | if (!user_mode(regs)) { |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 62 | #endif |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 63 | preempt_disable(); |
| 64 | if (kprobe_running() && kprobe_fault_handler(regs, 14)) |
| 65 | ret = 1; |
| 66 | preempt_enable(); |
| 67 | } |
Anil S Keshavamurthy | 1bd858a | 2006-06-26 00:25:25 -0700 | [diff] [blame] | 68 | |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 69 | return ret; |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 70 | #else |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 71 | return 0; |
Christoph Hellwig | 74a0b57 | 2007-10-16 01:24:07 -0700 | [diff] [blame] | 72 | #endif |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 73 | } |
Anil S Keshavamurthy | 1bd858a | 2006-06-26 00:25:25 -0700 | [diff] [blame] | 74 | |
Harvey Harrison | 1dc85be | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 75 | /* |
| 76 | * X86_32 |
| 77 | * Sometimes AMD Athlon/Opteron CPUs report invalid exceptions on prefetch. |
| 78 | * Check that here and ignore it. |
| 79 | * |
| 80 | * X86_64 |
| 81 | * Sometimes the CPU reports invalid exceptions on prefetch. |
| 82 | * Check that here and ignore it. |
| 83 | * |
| 84 | * Opcode checker based on code by Richard Brunner |
| 85 | */ |
| 86 | static int is_prefetch(struct pt_regs *regs, unsigned long addr, |
| 87 | unsigned long error_code) |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 88 | { |
Andi Kleen | ab2bf0c | 2006-12-07 02:14:06 +0100 | [diff] [blame] | 89 | unsigned char *instr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 90 | int scan_more = 1; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 91 | int prefetch = 0; |
Andi Kleen | f1290ec | 2005-04-16 15:24:59 -0700 | [diff] [blame] | 92 | unsigned char *max_instr; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 93 | |
Harvey Harrison | 1dc85be | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 94 | #ifdef CONFIG_X86_32 |
Harvey Harrison | b406ac6 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 95 | if (!(__supported_pte_mask & _PAGE_NX)) |
Harvey Harrison | 1dc85be | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 96 | return 0; |
Harvey Harrison | b406ac6 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 97 | #endif |
| 98 | |
Harvey Harrison | c61e211 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 99 | /* If it was a exec fault on NX page, ignore */ |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 100 | if (error_code & PF_INSTR) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 101 | return 0; |
Harvey Harrison | 1dc85be | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 102 | |
Harvey Harrison | f2857ce | 2008-01-30 13:33:12 +0100 | [diff] [blame] | 103 | instr = (unsigned char *)convert_ip_to_linear(current, regs); |
Andi Kleen | f1290ec | 2005-04-16 15:24:59 -0700 | [diff] [blame] | 104 | max_instr = instr + 15; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 105 | |
Vincent Hanquez | 76381fe | 2005-06-23 00:08:46 -0700 | [diff] [blame] | 106 | if (user_mode(regs) && instr >= (unsigned char *)TASK_SIZE) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 107 | return 0; |
| 108 | |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 109 | while (scan_more && instr < max_instr) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 110 | unsigned char opcode; |
| 111 | unsigned char instr_hi; |
| 112 | unsigned char instr_lo; |
| 113 | |
Andi Kleen | ab2bf0c | 2006-12-07 02:14:06 +0100 | [diff] [blame] | 114 | if (probe_kernel_address(instr, opcode)) |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 115 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 117 | instr_hi = opcode & 0xf0; |
| 118 | instr_lo = opcode & 0x0f; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 119 | instr++; |
| 120 | |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 121 | switch (instr_hi) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 122 | case 0x20: |
| 123 | case 0x30: |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 124 | /* |
| 125 | * Values 0x26,0x2E,0x36,0x3E are valid x86 prefixes. |
| 126 | * In X86_64 long mode, the CPU will signal invalid |
| 127 | * opcode if some of these prefixes are present so |
| 128 | * X86_64 will never get here anyway |
| 129 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 130 | scan_more = ((instr_lo & 7) == 0x6); |
| 131 | break; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 132 | #ifdef CONFIG_X86_64 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 133 | case 0x40: |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 134 | /* |
| 135 | * In AMD64 long mode 0x40..0x4F are valid REX prefixes |
| 136 | * Need to figure out under what instruction mode the |
| 137 | * instruction was issued. Could check the LDT for lm, |
| 138 | * but for now it's good enough to assume that long |
| 139 | * mode only uses well known segments or kernel. |
| 140 | */ |
Vincent Hanquez | 76381fe | 2005-06-23 00:08:46 -0700 | [diff] [blame] | 141 | scan_more = (!user_mode(regs)) || (regs->cs == __USER_CS); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 142 | break; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 143 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 144 | case 0x60: |
| 145 | /* 0x64 thru 0x67 are valid prefixes in all modes. */ |
| 146 | scan_more = (instr_lo & 0xC) == 0x4; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 147 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 148 | case 0xF0: |
Harvey Harrison | 1dc85be | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 149 | /* 0xF0, 0xF2, 0xF3 are valid prefixes in all modes. */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 150 | scan_more = !instr_lo || (instr_lo>>1) == 1; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 151 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 152 | case 0x00: |
| 153 | /* Prefetch instruction is 0x0F0D or 0x0F18 */ |
| 154 | scan_more = 0; |
Harvey Harrison | f2857ce | 2008-01-30 13:33:12 +0100 | [diff] [blame] | 155 | |
Andi Kleen | ab2bf0c | 2006-12-07 02:14:06 +0100 | [diff] [blame] | 156 | if (probe_kernel_address(instr, opcode)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 157 | break; |
| 158 | prefetch = (instr_lo == 0xF) && |
| 159 | (opcode == 0x0D || opcode == 0x18); |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 160 | break; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 161 | default: |
| 162 | scan_more = 0; |
| 163 | break; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 164 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | } |
| 166 | return prefetch; |
| 167 | } |
| 168 | |
Harvey Harrison | c4aba4a | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 169 | static void force_sig_info_fault(int si_signo, int si_code, |
| 170 | unsigned long address, struct task_struct *tsk) |
| 171 | { |
| 172 | siginfo_t info; |
| 173 | |
| 174 | info.si_signo = si_signo; |
| 175 | info.si_errno = 0; |
| 176 | info.si_code = si_code; |
| 177 | info.si_addr = (void __user *)address; |
| 178 | force_sig_info(si_signo, &info, tsk); |
| 179 | } |
| 180 | |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 181 | #ifdef CONFIG_X86_64 |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 182 | static int bad_address(void *p) |
| 183 | { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 184 | unsigned long dummy; |
Andi Kleen | ab2bf0c | 2006-12-07 02:14:06 +0100 | [diff] [blame] | 185 | return probe_kernel_address((unsigned long *)p, dummy); |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 186 | } |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 187 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 188 | |
| 189 | void dump_pagetable(unsigned long address) |
| 190 | { |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 191 | #ifdef CONFIG_X86_32 |
| 192 | __typeof__(pte_val(__pte(0))) page; |
| 193 | |
| 194 | page = read_cr3(); |
| 195 | page = ((__typeof__(page) *) __va(page))[address >> PGDIR_SHIFT]; |
| 196 | #ifdef CONFIG_X86_PAE |
| 197 | printk("*pdpt = %016Lx ", page); |
| 198 | if ((page >> PAGE_SHIFT) < max_low_pfn |
| 199 | && page & _PAGE_PRESENT) { |
| 200 | page &= PAGE_MASK; |
| 201 | page = ((__typeof__(page) *) __va(page))[(address >> PMD_SHIFT) |
| 202 | & (PTRS_PER_PMD - 1)]; |
| 203 | printk(KERN_CONT "*pde = %016Lx ", page); |
| 204 | page &= ~_PAGE_NX; |
| 205 | } |
| 206 | #else |
| 207 | printk("*pde = %08lx ", page); |
| 208 | #endif |
| 209 | |
| 210 | /* |
| 211 | * We must not directly access the pte in the highpte |
| 212 | * case if the page table is located in highmem. |
| 213 | * And let's rather not kmap-atomic the pte, just in case |
| 214 | * it's allocated already. |
| 215 | */ |
| 216 | if ((page >> PAGE_SHIFT) < max_low_pfn |
| 217 | && (page & _PAGE_PRESENT) |
| 218 | && !(page & _PAGE_PSE)) { |
| 219 | page &= PAGE_MASK; |
| 220 | page = ((__typeof__(page) *) __va(page))[(address >> PAGE_SHIFT) |
| 221 | & (PTRS_PER_PTE - 1)]; |
| 222 | printk("*pte = %0*Lx ", sizeof(page)*2, (u64)page); |
| 223 | } |
| 224 | |
| 225 | printk("\n"); |
| 226 | #else /* CONFIG_X86_64 */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 227 | pgd_t *pgd; |
| 228 | pud_t *pud; |
| 229 | pmd_t *pmd; |
| 230 | pte_t *pte; |
| 231 | |
Glauber de Oliveira Costa | f51c945 | 2007-07-22 11:12:29 +0200 | [diff] [blame] | 232 | pgd = (pgd_t *)read_cr3(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 233 | |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 234 | pgd = __va((unsigned long)pgd & PHYSICAL_PAGE_MASK); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | pgd += pgd_index(address); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 236 | if (bad_address(pgd)) goto bad; |
Jan Beulich | d646bce | 2006-02-03 21:51:47 +0100 | [diff] [blame] | 237 | printk("PGD %lx ", pgd_val(*pgd)); |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 238 | if (!pgd_present(*pgd)) goto ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 239 | |
Andi Kleen | d2ae5b5 | 2006-06-26 13:57:56 +0200 | [diff] [blame] | 240 | pud = pud_offset(pgd, address); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 241 | if (bad_address(pud)) goto bad; |
| 242 | printk("PUD %lx ", pud_val(*pud)); |
| 243 | if (!pud_present(*pud)) goto ret; |
| 244 | |
| 245 | pmd = pmd_offset(pud, address); |
| 246 | if (bad_address(pmd)) goto bad; |
| 247 | printk("PMD %lx ", pmd_val(*pmd)); |
Jan Beulich | b1992df | 2007-10-19 20:35:03 +0200 | [diff] [blame] | 248 | if (!pmd_present(*pmd) || pmd_large(*pmd)) goto ret; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 249 | |
| 250 | pte = pte_offset_kernel(pmd, address); |
| 251 | if (bad_address(pte)) goto bad; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 252 | printk("PTE %lx", pte_val(*pte)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 253 | ret: |
| 254 | printk("\n"); |
| 255 | return; |
| 256 | bad: |
| 257 | printk("BAD\n"); |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 258 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 259 | } |
| 260 | |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 261 | #ifdef CONFIG_X86_32 |
| 262 | static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) |
| 263 | { |
| 264 | unsigned index = pgd_index(address); |
| 265 | pgd_t *pgd_k; |
| 266 | pud_t *pud, *pud_k; |
| 267 | pmd_t *pmd, *pmd_k; |
| 268 | |
| 269 | pgd += index; |
| 270 | pgd_k = init_mm.pgd + index; |
| 271 | |
| 272 | if (!pgd_present(*pgd_k)) |
| 273 | return NULL; |
| 274 | |
| 275 | /* |
| 276 | * set_pgd(pgd, *pgd_k); here would be useless on PAE |
| 277 | * and redundant with the set_pmd() on non-PAE. As would |
| 278 | * set_pud. |
| 279 | */ |
| 280 | |
| 281 | pud = pud_offset(pgd, address); |
| 282 | pud_k = pud_offset(pgd_k, address); |
| 283 | if (!pud_present(*pud_k)) |
| 284 | return NULL; |
| 285 | |
| 286 | pmd = pmd_offset(pud, address); |
| 287 | pmd_k = pmd_offset(pud_k, address); |
| 288 | if (!pmd_present(*pmd_k)) |
| 289 | return NULL; |
| 290 | if (!pmd_present(*pmd)) { |
| 291 | set_pmd(pmd, *pmd_k); |
| 292 | arch_flush_lazy_mmu_mode(); |
| 293 | } else |
| 294 | BUG_ON(pmd_page(*pmd) != pmd_page(*pmd_k)); |
| 295 | return pmd_k; |
| 296 | } |
| 297 | #endif |
| 298 | |
Harvey Harrison | 1dc85be | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 299 | #ifdef CONFIG_X86_64 |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 300 | static const char errata93_warning[] = |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 301 | KERN_ERR "******* Your BIOS seems to not contain a fix for K8 errata #93\n" |
| 302 | KERN_ERR "******* Working around it, but it may cause SEGVs or burn power.\n" |
| 303 | KERN_ERR "******* Please consider a BIOS update.\n" |
| 304 | KERN_ERR "******* Disabling USB legacy in the BIOS may also help.\n"; |
Harvey Harrison | fdfe8aa | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 305 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 306 | |
| 307 | /* Workaround for K8 erratum #93 & buggy BIOS. |
| 308 | BIOS SMM functions are required to use a specific workaround |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 309 | to avoid corruption of the 64bit RIP register on C stepping K8. |
| 310 | A lot of BIOS that didn't get tested properly miss this. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 311 | The OS sees this as a page fault with the upper 32bits of RIP cleared. |
| 312 | Try to work around it here. |
Harvey Harrison | fdfe8aa | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 313 | Note we only handle faults in kernel here. |
| 314 | Does nothing for X86_32 |
| 315 | */ |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 316 | static int is_errata93(struct pt_regs *regs, unsigned long address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 317 | { |
Harvey Harrison | fdfe8aa | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 318 | #ifdef CONFIG_X86_64 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 319 | static int warned; |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 320 | if (address != regs->ip) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 321 | return 0; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 322 | if ((address >> 32) != 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 323 | return 0; |
| 324 | address |= 0xffffffffUL << 32; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 325 | if ((address >= (u64)_stext && address <= (u64)_etext) || |
| 326 | (address >= MODULES_VADDR && address <= MODULES_END)) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 327 | if (!warned) { |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 328 | printk(errata93_warning); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 329 | warned = 1; |
| 330 | } |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 331 | regs->ip = address; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 332 | return 1; |
| 333 | } |
Harvey Harrison | fdfe8aa | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 334 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 335 | return 0; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 336 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 337 | |
Harvey Harrison | 35f3266 | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 338 | /* |
| 339 | * Work around K8 erratum #100 K8 in compat mode occasionally jumps to illegal |
| 340 | * addresses >4GB. We catch this in the page fault handler because these |
| 341 | * addresses are not reachable. Just detect this case and return. Any code |
| 342 | * segment in LDT is compatibility mode. |
| 343 | */ |
| 344 | static int is_errata100(struct pt_regs *regs, unsigned long address) |
| 345 | { |
| 346 | #ifdef CONFIG_X86_64 |
| 347 | if ((regs->cs == __USER32_CS || (regs->cs & (1<<2))) && |
| 348 | (address >> 32)) |
| 349 | return 1; |
| 350 | #endif |
| 351 | return 0; |
| 352 | } |
| 353 | |
Harvey Harrison | 29caf2f | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 354 | void do_invalid_op(struct pt_regs *, unsigned long); |
| 355 | |
| 356 | static int is_f00f_bug(struct pt_regs *regs, unsigned long address) |
| 357 | { |
| 358 | #ifdef CONFIG_X86_F00F_BUG |
| 359 | unsigned long nr; |
| 360 | /* |
| 361 | * Pentium F0 0F C7 C8 bug workaround. |
| 362 | */ |
| 363 | if (boot_cpu_data.f00f_bug) { |
| 364 | nr = (address - idt_descr.address) >> 3; |
| 365 | |
| 366 | if (nr == 6) { |
| 367 | do_invalid_op(regs, 0); |
| 368 | return 1; |
| 369 | } |
| 370 | } |
| 371 | #endif |
| 372 | return 0; |
| 373 | } |
| 374 | |
Harvey Harrison | b3279c7 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 375 | static void show_fault_oops(struct pt_regs *regs, unsigned long error_code, |
| 376 | unsigned long address) |
| 377 | { |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 378 | #ifdef CONFIG_X86_32 |
| 379 | if (!oops_may_print()) |
| 380 | return; |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 381 | #endif |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 382 | |
| 383 | #ifdef CONFIG_X86_PAE |
| 384 | if (error_code & PF_INSTR) { |
Harvey Harrison | 93809be | 2008-02-01 17:49:43 +0100 | [diff] [blame] | 385 | unsigned int level; |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 386 | pte_t *pte = lookup_address(address, &level); |
| 387 | |
| 388 | if (pte && pte_present(*pte) && !pte_exec(*pte)) |
| 389 | printk(KERN_CRIT "kernel tried to execute " |
| 390 | "NX-protected page - exploit attempt? " |
| 391 | "(uid: %d)\n", current->uid); |
| 392 | } |
| 393 | #endif |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 394 | |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 395 | printk(KERN_ALERT "BUG: unable to handle kernel "); |
| 396 | if (address < PAGE_SIZE) |
| 397 | printk(KERN_CONT "NULL pointer dereference"); |
| 398 | else |
| 399 | printk(KERN_CONT "paging request"); |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 400 | #ifdef CONFIG_X86_32 |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 401 | printk(KERN_CONT " at %08lx\n", address); |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 402 | #else |
Harvey Harrison | 19f0dda | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 403 | printk(KERN_CONT " at %016lx\n", address); |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 404 | #endif |
Harvey Harrison | 19f0dda | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 405 | printk(KERN_ALERT "IP:"); |
Harvey Harrison | b3279c7 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 406 | printk_address(regs->ip, 1); |
| 407 | dump_pagetable(address); |
| 408 | } |
| 409 | |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 410 | #ifdef CONFIG_X86_64 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 411 | static noinline void pgtable_bad(unsigned long address, struct pt_regs *regs, |
| 412 | unsigned long error_code) |
| 413 | { |
Jan Beulich | 1209140 | 2005-09-12 18:49:24 +0200 | [diff] [blame] | 414 | unsigned long flags = oops_begin(); |
Jan Beulich | 6e3f361 | 2006-01-11 22:42:14 +0100 | [diff] [blame] | 415 | struct task_struct *tsk; |
Jan Beulich | 1209140 | 2005-09-12 18:49:24 +0200 | [diff] [blame] | 416 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 417 | printk(KERN_ALERT "%s: Corrupted page table at address %lx\n", |
| 418 | current->comm, address); |
| 419 | dump_pagetable(address); |
Jan Beulich | 6e3f361 | 2006-01-11 22:42:14 +0100 | [diff] [blame] | 420 | tsk = current; |
| 421 | tsk->thread.cr2 = address; |
| 422 | tsk->thread.trap_no = 14; |
| 423 | tsk->thread.error_code = error_code; |
Jan Beulich | 22f5991 | 2008-01-30 13:31:23 +0100 | [diff] [blame] | 424 | if (__die("Bad pagetable", regs, error_code)) |
| 425 | regs = NULL; |
| 426 | oops_end(flags, regs, SIGKILL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 427 | } |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 428 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 429 | |
| 430 | /* |
Jeremy Fitzhardinge | 5b727a3 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 431 | * Handle a spurious fault caused by a stale TLB entry. This allows |
| 432 | * us to lazily refresh the TLB when increasing the permissions of a |
| 433 | * kernel page (RO -> RW or NX -> X). Doing it eagerly is very |
| 434 | * expensive since that implies doing a full cross-processor TLB |
| 435 | * flush, even if no stale TLB entries exist on other processors. |
| 436 | * There are no security implications to leaving a stale TLB when |
| 437 | * increasing the permissions on a page. |
| 438 | */ |
| 439 | static int spurious_fault(unsigned long address, |
| 440 | unsigned long error_code) |
| 441 | { |
| 442 | pgd_t *pgd; |
| 443 | pud_t *pud; |
| 444 | pmd_t *pmd; |
| 445 | pte_t *pte; |
| 446 | |
| 447 | /* Reserved-bit violation or user access to kernel space? */ |
| 448 | if (error_code & (PF_USER | PF_RSVD)) |
| 449 | return 0; |
| 450 | |
| 451 | pgd = init_mm.pgd + pgd_index(address); |
| 452 | if (!pgd_present(*pgd)) |
| 453 | return 0; |
| 454 | |
| 455 | pud = pud_offset(pgd, address); |
| 456 | if (!pud_present(*pud)) |
| 457 | return 0; |
| 458 | |
| 459 | pmd = pmd_offset(pud, address); |
| 460 | if (!pmd_present(*pmd)) |
| 461 | return 0; |
| 462 | |
| 463 | pte = pte_offset_kernel(pmd, address); |
| 464 | if (!pte_present(*pte)) |
| 465 | return 0; |
| 466 | |
| 467 | if ((error_code & PF_WRITE) && !pte_write(*pte)) |
| 468 | return 0; |
| 469 | if ((error_code & PF_INSTR) && !pte_exec(*pte)) |
| 470 | return 0; |
| 471 | |
| 472 | return 1; |
| 473 | } |
| 474 | |
| 475 | /* |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 476 | * X86_32 |
| 477 | * Handle a fault on the vmalloc or module mapping area |
| 478 | * |
| 479 | * X86_64 |
Andi Kleen | f95190b | 2006-01-11 22:44:00 +0100 | [diff] [blame] | 480 | * Handle a fault on the vmalloc area |
Andi Kleen | 3b9ba4d | 2005-05-16 21:53:31 -0700 | [diff] [blame] | 481 | * |
| 482 | * This assumes no large pages in there. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 483 | */ |
| 484 | static int vmalloc_fault(unsigned long address) |
| 485 | { |
Harvey Harrison | fdfe8aa | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 486 | #ifdef CONFIG_X86_32 |
| 487 | unsigned long pgd_paddr; |
| 488 | pmd_t *pmd_k; |
| 489 | pte_t *pte_k; |
| 490 | /* |
| 491 | * Synchronize this task's top level page-table |
| 492 | * with the 'reference' page table. |
| 493 | * |
| 494 | * Do _not_ use "current" here. We might be inside |
| 495 | * an interrupt in the middle of a task switch.. |
| 496 | */ |
| 497 | pgd_paddr = read_cr3(); |
| 498 | pmd_k = vmalloc_sync_one(__va(pgd_paddr), address); |
| 499 | if (!pmd_k) |
| 500 | return -1; |
| 501 | pte_k = pte_offset_kernel(pmd_k, address); |
| 502 | if (!pte_present(*pte_k)) |
| 503 | return -1; |
| 504 | return 0; |
| 505 | #else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 506 | pgd_t *pgd, *pgd_ref; |
| 507 | pud_t *pud, *pud_ref; |
| 508 | pmd_t *pmd, *pmd_ref; |
| 509 | pte_t *pte, *pte_ref; |
| 510 | |
Harvey Harrison | cf89ec9 | 2008-02-04 16:47:56 +0100 | [diff] [blame^] | 511 | /* Make sure we are in vmalloc area */ |
| 512 | if (!(address >= VMALLOC_START && address < VMALLOC_END)) |
| 513 | return -1; |
| 514 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 515 | /* Copy kernel mappings over when needed. This can also |
| 516 | happen within a race in page table update. In the later |
| 517 | case just flush. */ |
| 518 | |
| 519 | pgd = pgd_offset(current->mm ?: &init_mm, address); |
| 520 | pgd_ref = pgd_offset_k(address); |
| 521 | if (pgd_none(*pgd_ref)) |
| 522 | return -1; |
| 523 | if (pgd_none(*pgd)) |
| 524 | set_pgd(pgd, *pgd_ref); |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 525 | else |
Dave McCracken | 46a82b2 | 2006-09-25 23:31:48 -0700 | [diff] [blame] | 526 | BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 527 | |
| 528 | /* Below here mismatches are bugs because these lower tables |
| 529 | are shared */ |
| 530 | |
| 531 | pud = pud_offset(pgd, address); |
| 532 | pud_ref = pud_offset(pgd_ref, address); |
| 533 | if (pud_none(*pud_ref)) |
| 534 | return -1; |
Dave McCracken | 46a82b2 | 2006-09-25 23:31:48 -0700 | [diff] [blame] | 535 | if (pud_none(*pud) || pud_page_vaddr(*pud) != pud_page_vaddr(*pud_ref)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 536 | BUG(); |
| 537 | pmd = pmd_offset(pud, address); |
| 538 | pmd_ref = pmd_offset(pud_ref, address); |
| 539 | if (pmd_none(*pmd_ref)) |
| 540 | return -1; |
| 541 | if (pmd_none(*pmd) || pmd_page(*pmd) != pmd_page(*pmd_ref)) |
| 542 | BUG(); |
| 543 | pte_ref = pte_offset_kernel(pmd_ref, address); |
| 544 | if (!pte_present(*pte_ref)) |
| 545 | return -1; |
| 546 | pte = pte_offset_kernel(pmd, address); |
Andi Kleen | 3b9ba4d | 2005-05-16 21:53:31 -0700 | [diff] [blame] | 547 | /* Don't use pte_page here, because the mappings can point |
| 548 | outside mem_map, and the NUMA hash lookup cannot handle |
| 549 | that. */ |
| 550 | if (!pte_present(*pte) || pte_pfn(*pte) != pte_pfn(*pte_ref)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 551 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 552 | return 0; |
Harvey Harrison | fdfe8aa | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 553 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 554 | } |
| 555 | |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 556 | int show_unhandled_signals = 1; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 557 | |
| 558 | /* |
| 559 | * This routine handles page faults. It determines the address, |
| 560 | * and the problem, and then passes it off to one of the appropriate |
| 561 | * routines. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 562 | */ |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 563 | #ifdef CONFIG_X86_64 |
| 564 | asmlinkage |
| 565 | #endif |
| 566 | void __kprobes do_page_fault(struct pt_regs *regs, unsigned long error_code) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 567 | { |
| 568 | struct task_struct *tsk; |
| 569 | struct mm_struct *mm; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 570 | struct vm_area_struct *vma; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 571 | unsigned long address; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 572 | int write, si_code; |
| 573 | int fault; |
| 574 | #ifdef CONFIG_X86_64 |
Jan Beulich | 1209140 | 2005-09-12 18:49:24 +0200 | [diff] [blame] | 575 | unsigned long flags; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 576 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 577 | |
Peter Zijlstra | 143a5d3 | 2007-10-25 14:01:10 +0200 | [diff] [blame] | 578 | /* |
| 579 | * We can fault from pretty much anywhere, with unknown IRQ state. |
| 580 | */ |
| 581 | trace_hardirqs_fixup(); |
| 582 | |
Arjan van de Ven | a9ba9a3 | 2006-03-25 16:30:10 +0100 | [diff] [blame] | 583 | tsk = current; |
| 584 | mm = tsk->mm; |
| 585 | prefetchw(&mm->mmap_sem); |
| 586 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 587 | /* get the address */ |
Glauber de Oliveira Costa | f51c945 | 2007-07-22 11:12:29 +0200 | [diff] [blame] | 588 | address = read_cr2(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 589 | |
Harvey Harrison | c4aba4a | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 590 | si_code = SEGV_MAPERR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 591 | |
Harvey Harrison | 608566b | 2008-01-30 13:33:12 +0100 | [diff] [blame] | 592 | if (notify_page_fault(regs)) |
| 593 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 594 | |
| 595 | /* |
| 596 | * We fault-in kernel-space virtual memory on-demand. The |
| 597 | * 'reference' page table is init_mm.pgd. |
| 598 | * |
| 599 | * NOTE! We MUST NOT take any locks for this case. We may |
| 600 | * be in an interrupt or a critical region, and should |
| 601 | * only copy the information from the master page table, |
| 602 | * nothing more. |
| 603 | * |
| 604 | * This verifies that the fault happens in kernel space |
| 605 | * (error_code & 4) == 0, and that the fault was not a |
Jan Beulich | 8b1bde9 | 2006-01-11 22:42:23 +0100 | [diff] [blame] | 606 | * protection error (error_code & 9) == 0. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 607 | */ |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 608 | #ifdef CONFIG_X86_32 |
| 609 | if (unlikely(address >= TASK_SIZE)) { |
Harvey Harrison | cf89ec9 | 2008-02-04 16:47:56 +0100 | [diff] [blame^] | 610 | #else |
| 611 | if (unlikely(address >= TASK_SIZE64)) { |
| 612 | #endif |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 613 | if (!(error_code & (PF_RSVD|PF_USER|PF_PROT)) && |
| 614 | vmalloc_fault(address) >= 0) |
| 615 | return; |
Jeremy Fitzhardinge | 5b727a3 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 616 | |
| 617 | /* Can handle a stale RO->RW TLB */ |
| 618 | if (spurious_fault(address, error_code)) |
| 619 | return; |
| 620 | |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 621 | /* |
| 622 | * Don't take the mm semaphore here. If we fixup a prefetch |
| 623 | * fault we could otherwise deadlock. |
| 624 | */ |
| 625 | goto bad_area_nosemaphore; |
| 626 | } |
| 627 | |
Harvey Harrison | cf89ec9 | 2008-02-04 16:47:56 +0100 | [diff] [blame^] | 628 | |
| 629 | #ifdef CONFIG_X86_32 |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 630 | /* It's safe to allow irq's after cr2 has been saved and the vmalloc |
| 631 | fault has been handled. */ |
| 632 | if (regs->flags & (X86_EFLAGS_IF|VM_MASK)) |
| 633 | local_irq_enable(); |
| 634 | |
| 635 | /* |
| 636 | * If we're in an interrupt, have no user context or are running in an |
| 637 | * atomic region then we must not take the fault. |
| 638 | */ |
| 639 | if (in_atomic() || !mm) |
| 640 | goto bad_area_nosemaphore; |
| 641 | #else /* CONFIG_X86_64 */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 642 | if (likely(regs->flags & X86_EFLAGS_IF)) |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 643 | local_irq_enable(); |
| 644 | |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 645 | if (unlikely(error_code & PF_RSVD)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 646 | pgtable_bad(address, regs, error_code); |
| 647 | |
| 648 | /* |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 649 | * If we're in an interrupt, have no user context or are running in an |
| 650 | * atomic region then we must not take the fault. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 651 | */ |
| 652 | if (unlikely(in_atomic() || !mm)) |
| 653 | goto bad_area_nosemaphore; |
| 654 | |
Linus Torvalds | dbe3ed1 | 2007-09-19 11:37:14 -0700 | [diff] [blame] | 655 | /* |
| 656 | * User-mode registers count as a user access even for any |
| 657 | * potential system fault or CPU buglet. |
| 658 | */ |
| 659 | if (user_mode_vm(regs)) |
| 660 | error_code |= PF_USER; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 661 | again: |
| 662 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 663 | /* When running in the kernel we expect faults to occur only to |
| 664 | * addresses in user space. All other faults represent errors in the |
Simon Arlott | 676b185 | 2007-10-20 01:25:36 +0200 | [diff] [blame] | 665 | * kernel and should generate an OOPS. Unfortunately, in the case of an |
Adrian Bunk | 80f7228 | 2006-06-30 18:27:16 +0200 | [diff] [blame] | 666 | * erroneous fault occurring in a code path which already holds mmap_sem |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 667 | * we will deadlock attempting to validate the fault against the |
| 668 | * address space. Luckily the kernel only validly references user |
| 669 | * space from well defined areas of code, which are listed in the |
| 670 | * exceptions table. |
| 671 | * |
| 672 | * As the vast majority of faults will be valid we will only perform |
Simon Arlott | 676b185 | 2007-10-20 01:25:36 +0200 | [diff] [blame] | 673 | * the source reference check when there is a possibility of a deadlock. |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 674 | * Attempt to lock the address space, if we cannot we then validate the |
| 675 | * source. If this is invalid we can skip the address space check, |
| 676 | * thus avoiding the deadlock. |
| 677 | */ |
| 678 | if (!down_read_trylock(&mm->mmap_sem)) { |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 679 | if ((error_code & PF_USER) == 0 && |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 680 | !search_exception_tables(regs->ip)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 681 | goto bad_area_nosemaphore; |
| 682 | down_read(&mm->mmap_sem); |
| 683 | } |
| 684 | |
| 685 | vma = find_vma(mm, address); |
| 686 | if (!vma) |
| 687 | goto bad_area; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 688 | if (vma->vm_start <= address) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 689 | goto good_area; |
| 690 | if (!(vma->vm_flags & VM_GROWSDOWN)) |
| 691 | goto bad_area; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 692 | if (error_code & PF_USER) { |
Harvey Harrison | 6f4d368 | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 693 | /* |
| 694 | * Accessing the stack below %sp is always a bug. |
| 695 | * The large cushion allows instructions like enter |
| 696 | * and pusha to work. ("enter $65535,$31" pushes |
| 697 | * 32 pointers and then decrements %sp by 65535.) |
Chuck Ebbert | 03fdc2c | 2006-06-26 13:59:50 +0200 | [diff] [blame] | 698 | */ |
H. Peter Anvin | 65ea5b0 | 2008-01-30 13:30:56 +0100 | [diff] [blame] | 699 | if (address + 65536 + 32 * sizeof(unsigned long) < regs->sp) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 700 | goto bad_area; |
| 701 | } |
| 702 | if (expand_stack(vma, address)) |
| 703 | goto bad_area; |
| 704 | /* |
| 705 | * Ok, we have a good vm_area for this memory access, so |
| 706 | * we can handle it.. |
| 707 | */ |
| 708 | good_area: |
Harvey Harrison | c4aba4a | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 709 | si_code = SEGV_ACCERR; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 710 | write = 0; |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 711 | switch (error_code & (PF_PROT|PF_WRITE)) { |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 712 | default: /* 3: write, present */ |
| 713 | /* fall through */ |
| 714 | case PF_WRITE: /* write, not present */ |
| 715 | if (!(vma->vm_flags & VM_WRITE)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 716 | goto bad_area; |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 717 | write++; |
| 718 | break; |
| 719 | case PF_PROT: /* read, present */ |
| 720 | goto bad_area; |
| 721 | case 0: /* read, not present */ |
| 722 | if (!(vma->vm_flags & (VM_READ | VM_EXEC | VM_WRITE))) |
| 723 | goto bad_area; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 724 | } |
| 725 | |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 726 | #ifdef CONFIG_X86_32 |
| 727 | survive: |
| 728 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 729 | /* |
| 730 | * If for any reason at all we couldn't handle the fault, |
| 731 | * make sure we exit gracefully rather than endlessly redo |
| 732 | * the fault. |
| 733 | */ |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 734 | fault = handle_mm_fault(mm, vma, address, write); |
| 735 | if (unlikely(fault & VM_FAULT_ERROR)) { |
| 736 | if (fault & VM_FAULT_OOM) |
| 737 | goto out_of_memory; |
| 738 | else if (fault & VM_FAULT_SIGBUS) |
| 739 | goto do_sigbus; |
| 740 | BUG(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 741 | } |
Nick Piggin | 83c5407 | 2007-07-19 01:47:05 -0700 | [diff] [blame] | 742 | if (fault & VM_FAULT_MAJOR) |
| 743 | tsk->maj_flt++; |
| 744 | else |
| 745 | tsk->min_flt++; |
Harvey Harrison | d729ab3 | 2008-01-30 13:33:23 +0100 | [diff] [blame] | 746 | |
| 747 | #ifdef CONFIG_X86_32 |
| 748 | /* |
| 749 | * Did it hit the DOS screen memory VA from vm86 mode? |
| 750 | */ |
| 751 | if (v8086_mode(regs)) { |
| 752 | unsigned long bit = (address - 0xA0000) >> PAGE_SHIFT; |
| 753 | if (bit < 32) |
| 754 | tsk->thread.screen_bitmap |= 1 << bit; |
| 755 | } |
| 756 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 757 | up_read(&mm->mmap_sem); |
| 758 | return; |
| 759 | |
| 760 | /* |
| 761 | * Something tried to access memory that isn't in our memory map.. |
| 762 | * Fix it, but check if it's kernel or user first.. |
| 763 | */ |
| 764 | bad_area: |
| 765 | up_read(&mm->mmap_sem); |
| 766 | |
| 767 | bad_area_nosemaphore: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 768 | /* User mode accesses just cause a SIGSEGV */ |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 769 | if (error_code & PF_USER) { |
Steven Rostedt | e5e3c84 | 2007-06-06 23:34:04 -0400 | [diff] [blame] | 770 | /* |
| 771 | * It's possible to have interrupts off here. |
| 772 | */ |
| 773 | local_irq_enable(); |
| 774 | |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 775 | /* |
| 776 | * Valid to do another page fault here because this one came |
| 777 | * from user space. |
| 778 | */ |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 779 | if (is_prefetch(regs, address, error_code)) |
| 780 | return; |
| 781 | |
Harvey Harrison | 35f3266 | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 782 | if (is_errata100(regs, address)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 783 | return; |
| 784 | |
Masoud Asgharifard Sharbiani | abd4f75 | 2007-07-22 11:12:28 +0200 | [diff] [blame] | 785 | if (show_unhandled_signals && unhandled_signal(tsk, SIGSEGV) && |
| 786 | printk_ratelimit()) { |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 787 | printk( |
Harvey Harrison | 6f4d368 | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 788 | #ifdef CONFIG_X86_32 |
Harvey Harrison | edcd811 | 2008-01-30 13:33:16 +0100 | [diff] [blame] | 789 | "%s%s[%d]: segfault at %lx ip %08lx sp %08lx error %lx", |
Harvey Harrison | 6f4d368 | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 790 | #else |
Andi Kleen | 0325291 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 791 | "%s%s[%d]: segfault at %lx ip %lx sp %lx error %lx", |
Harvey Harrison | 6f4d368 | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 792 | #endif |
| 793 | task_pid_nr(tsk) > 1 ? KERN_INFO : KERN_EMERG, |
| 794 | tsk->comm, task_pid_nr(tsk), address, regs->ip, |
| 795 | regs->sp, error_code); |
Andi Kleen | 0325291 | 2008-01-30 13:33:18 +0100 | [diff] [blame] | 796 | print_vma_addr(" in ", regs->ip); |
| 797 | printk("\n"); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 798 | } |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 799 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 800 | tsk->thread.cr2 = address; |
| 801 | /* Kernel addresses are always protection faults */ |
| 802 | tsk->thread.error_code = error_code | (address >= TASK_SIZE); |
| 803 | tsk->thread.trap_no = 14; |
Harvey Harrison | c4aba4a | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 804 | force_sig_info_fault(SIGSEGV, si_code, address, tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 805 | return; |
| 806 | } |
| 807 | |
Harvey Harrison | 29caf2f | 2008-01-30 13:34:09 +0100 | [diff] [blame] | 808 | if (is_f00f_bug(regs, address)) |
| 809 | return; |
| 810 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 811 | no_context: |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 812 | /* Are we prepared to handle this kernel fault? */ |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 813 | if (fixup_exception(regs)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 814 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 815 | |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 816 | /* |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 817 | * X86_32 |
| 818 | * Valid to do another page fault here, because if this fault |
| 819 | * had been triggered by is_prefetch fixup_exception would have |
| 820 | * handled it. |
| 821 | * |
| 822 | * X86_64 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 823 | * Hall of shame of CPU/BIOS bugs. |
| 824 | */ |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 825 | if (is_prefetch(regs, address, error_code)) |
| 826 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 827 | |
| 828 | if (is_errata93(regs, address)) |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 829 | return; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 830 | |
| 831 | /* |
| 832 | * Oops. The kernel tried to access some bad page. We'll have to |
| 833 | * terminate things with extreme prejudice. |
| 834 | */ |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 835 | #ifdef CONFIG_X86_32 |
| 836 | bust_spinlocks(1); |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 837 | #else |
| 838 | flags = oops_begin(); |
| 839 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 840 | |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 841 | show_fault_oops(regs, error_code, address); |
| 842 | |
| 843 | tsk->thread.cr2 = address; |
| 844 | tsk->thread.trap_no = 14; |
| 845 | tsk->thread.error_code = error_code; |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 846 | |
| 847 | #ifdef CONFIG_X86_32 |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 848 | die("Oops", regs, error_code); |
| 849 | bust_spinlocks(0); |
| 850 | do_exit(SIGKILL); |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 851 | #else |
Jan Beulich | 22f5991 | 2008-01-30 13:31:23 +0100 | [diff] [blame] | 852 | if (__die("Oops", regs, error_code)) |
| 853 | regs = NULL; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 854 | /* Executive summary in case the body of the oops scrolled away */ |
| 855 | printk(KERN_EMERG "CR2: %016lx\n", address); |
Jan Beulich | 22f5991 | 2008-01-30 13:31:23 +0100 | [diff] [blame] | 856 | oops_end(flags, regs, SIGKILL); |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 857 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 858 | |
| 859 | /* |
| 860 | * We ran out of memory, or some other thing happened to us that made |
| 861 | * us unable to handle the page fault gracefully. |
| 862 | */ |
| 863 | out_of_memory: |
| 864 | up_read(&mm->mmap_sem); |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 865 | if (is_global_init(tsk)) { |
| 866 | yield(); |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 867 | #ifdef CONFIG_X86_32 |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 868 | down_read(&mm->mmap_sem); |
| 869 | goto survive; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 870 | #else |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 871 | goto again; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 872 | #endif |
Harvey Harrison | fd40d6e | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 873 | } |
| 874 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 875 | printk("VM: killing process %s\n", tsk->comm); |
Harvey Harrison | 318aa29 | 2008-01-30 13:32:59 +0100 | [diff] [blame] | 876 | if (error_code & PF_USER) |
Will Schmidt | 021daae | 2007-07-21 17:11:17 +0200 | [diff] [blame] | 877 | do_group_exit(SIGKILL); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 878 | goto no_context; |
| 879 | |
| 880 | do_sigbus: |
| 881 | up_read(&mm->mmap_sem); |
| 882 | |
| 883 | /* Kernel mode? Handle exceptions or die */ |
Andi Kleen | 66c5815 | 2006-01-11 22:44:09 +0100 | [diff] [blame] | 884 | if (!(error_code & PF_USER)) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 885 | goto no_context; |
Harvey Harrison | f8c2ee2 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 886 | #ifdef CONFIG_X86_32 |
| 887 | /* User space => ok to do another page fault */ |
| 888 | if (is_prefetch(regs, address, error_code)) |
| 889 | return; |
| 890 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 891 | tsk->thread.cr2 = address; |
| 892 | tsk->thread.error_code = error_code; |
| 893 | tsk->thread.trap_no = 14; |
Harvey Harrison | c4aba4a | 2008-01-30 13:32:35 +0100 | [diff] [blame] | 894 | force_sig_info_fault(SIGBUS, BUS_ADRERR, address, tsk); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 895 | } |
Andi Kleen | 9e43e1b | 2005-11-05 17:25:54 +0100 | [diff] [blame] | 896 | |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 897 | DEFINE_SPINLOCK(pgd_lock); |
Christoph Lameter | 2bff738 | 2007-05-02 19:27:10 +0200 | [diff] [blame] | 898 | LIST_HEAD(pgd_list); |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 899 | |
| 900 | void vmalloc_sync_all(void) |
| 901 | { |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 902 | #ifdef CONFIG_X86_32 |
| 903 | /* |
| 904 | * Note that races in the updates of insync and start aren't |
| 905 | * problematic: insync can only get set bits added, and updates to |
| 906 | * start are only improving performance (without affecting correctness |
| 907 | * if undone). |
| 908 | */ |
| 909 | static DECLARE_BITMAP(insync, PTRS_PER_PGD); |
| 910 | static unsigned long start = TASK_SIZE; |
| 911 | unsigned long address; |
| 912 | |
| 913 | if (SHARED_KERNEL_PMD) |
| 914 | return; |
| 915 | |
| 916 | BUILD_BUG_ON(TASK_SIZE & ~PGDIR_MASK); |
| 917 | for (address = start; address >= TASK_SIZE; address += PGDIR_SIZE) { |
| 918 | if (!test_bit(pgd_index(address), insync)) { |
| 919 | unsigned long flags; |
| 920 | struct page *page; |
| 921 | |
| 922 | spin_lock_irqsave(&pgd_lock, flags); |
Jeremy Fitzhardinge | e3ed910 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 923 | list_for_each_entry(page, &pgd_list, lru) { |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 924 | if (!vmalloc_sync_one(page_address(page), |
Jeremy Fitzhardinge | e3ed910 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 925 | address)) |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 926 | break; |
Jeremy Fitzhardinge | e3ed910 | 2008-01-30 13:34:11 +0100 | [diff] [blame] | 927 | } |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 928 | spin_unlock_irqrestore(&pgd_lock, flags); |
| 929 | if (!page) |
| 930 | set_bit(pgd_index(address), insync); |
| 931 | } |
| 932 | if (address == start && test_bit(pgd_index(address), insync)) |
| 933 | start = address + PGDIR_SIZE; |
| 934 | } |
| 935 | #else /* CONFIG_X86_64 */ |
Harvey Harrison | 6f4d368 | 2008-01-30 13:33:13 +0100 | [diff] [blame] | 936 | /* |
| 937 | * Note that races in the updates of insync and start aren't |
| 938 | * problematic: insync can only get set bits added, and updates to |
| 939 | * start are only improving performance (without affecting correctness |
| 940 | * if undone). |
| 941 | */ |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 942 | static DECLARE_BITMAP(insync, PTRS_PER_PGD); |
| 943 | static unsigned long start = VMALLOC_START & PGDIR_MASK; |
| 944 | unsigned long address; |
| 945 | |
| 946 | for (address = start; address <= VMALLOC_END; address += PGDIR_SIZE) { |
| 947 | if (!test_bit(pgd_index(address), insync)) { |
| 948 | const pgd_t *pgd_ref = pgd_offset_k(address); |
| 949 | struct page *page; |
| 950 | |
| 951 | if (pgd_none(*pgd_ref)) |
| 952 | continue; |
| 953 | spin_lock(&pgd_lock); |
Christoph Lameter | 2bff738 | 2007-05-02 19:27:10 +0200 | [diff] [blame] | 954 | list_for_each_entry(page, &pgd_list, lru) { |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 955 | pgd_t *pgd; |
| 956 | pgd = (pgd_t *)page_address(page) + pgd_index(address); |
| 957 | if (pgd_none(*pgd)) |
| 958 | set_pgd(pgd, *pgd_ref); |
| 959 | else |
Dave McCracken | 46a82b2 | 2006-09-25 23:31:48 -0700 | [diff] [blame] | 960 | BUG_ON(pgd_page_vaddr(*pgd) != pgd_page_vaddr(*pgd_ref)); |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 961 | } |
| 962 | spin_unlock(&pgd_lock); |
| 963 | set_bit(pgd_index(address), insync); |
| 964 | } |
| 965 | if (address == start) |
| 966 | start = address + PGDIR_SIZE; |
| 967 | } |
| 968 | /* Check that there is no need to do the same for the modules area. */ |
| 969 | BUILD_BUG_ON(!(MODULES_VADDR > __START_KERNEL)); |
Harvey Harrison | 33cb524 | 2008-01-30 13:32:19 +0100 | [diff] [blame] | 970 | BUILD_BUG_ON(!(((MODULES_END - 1) & PGDIR_MASK) == |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 971 | (__START_KERNEL & PGDIR_MASK))); |
Harvey Harrison | 1156e09 | 2008-01-30 13:34:10 +0100 | [diff] [blame] | 972 | #endif |
Jan Beulich | 8c914cb | 2006-03-25 16:29:40 +0100 | [diff] [blame] | 973 | } |