This source file includes following definitions.
- do_page_fault
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7 #include <linux/signal.h>
8 #include <linux/sched.h>
9 #include <linux/head.h>
10 #include <linux/kernel.h>
11 #include <linux/errno.h>
12 #include <linux/string.h>
13 #include <linux/types.h>
14 #include <linux/ptrace.h>
15 #include <linux/mman.h>
16 #include <linux/mm.h>
17
18 #include <asm/system.h>
19 #include <asm/segment.h>
20 #include <asm/pgtable.h>
21
22 extern void die_if_kernel(const char *,struct pt_regs *,long);
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34 asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
35 {
36 struct vm_area_struct * vma;
37 unsigned long address;
38 unsigned long page;
39
40
41 __asm__("movl %%cr2,%0":"=r" (address));
42 vma = find_vma(current, address);
43 if (!vma)
44 goto bad_area;
45 if (vma->vm_start <= address)
46 goto good_area;
47 if (!(vma->vm_flags & VM_GROWSDOWN))
48 goto bad_area;
49 if (vma->vm_end - address > current->rlim[RLIMIT_STACK].rlim_cur)
50 goto bad_area;
51 if (error_code & 4) {
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58 if (address + 32 < regs->esp)
59 goto bad_area;
60 }
61 vma->vm_offset -= vma->vm_start - (address & PAGE_MASK);
62 vma->vm_start = (address & PAGE_MASK);
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67 good_area:
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71 if (error_code & 2) {
72 if (!(vma->vm_flags & VM_WRITE))
73 goto bad_area;
74 } else {
75
76 if (error_code & 1)
77 goto bad_area;
78 if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
79 goto bad_area;
80 }
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84 if (regs->eflags & VM_MASK) {
85 unsigned long bit = (address - 0xA0000) >> PAGE_SHIFT;
86 if (bit < 32)
87 current->tss.screen_bitmap |= 1 << bit;
88 }
89 if (error_code & 1) {
90 #ifdef TEST_VERIFY_AREA
91 if (regs->cs == KERNEL_CS)
92 printk("WP fault at %08x\n", regs->eip);
93 #endif
94 do_wp_page(current, vma, address, error_code & 2);
95 return;
96 }
97 do_no_page(current, vma, address, error_code & 2);
98 return;
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104 bad_area:
105 if (error_code & 4) {
106 current->tss.cr2 = address;
107 current->tss.error_code = error_code;
108 current->tss.trap_no = 14;
109 send_sig(SIGSEGV, current, 1);
110 return;
111 }
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118 if (wp_works_ok < 0 && address == TASK_SIZE && (error_code & 1)) {
119 wp_works_ok = 1;
120 pg0[0] = pte_val(mk_pte(0, PAGE_SHARED));
121 invalidate();
122 printk("This processor honours the WP bit even when in supervisor mode. Good.\n");
123 return;
124 }
125 if ((unsigned long) (address-TASK_SIZE) < PAGE_SIZE) {
126 printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
127 pg0[0] = pte_val(mk_pte(0, PAGE_SHARED));
128 } else
129 printk(KERN_ALERT "Unable to handle kernel paging request");
130 printk(" at virtual address %08lx\n",address);
131 __asm__("movl %%cr3,%0" : "=r" (page));
132 printk(KERN_ALERT "current->tss.cr3 = %08lx, %%cr3 = %08lx\n",
133 current->tss.cr3, page);
134 page = ((unsigned long *) page)[address >> 22];
135 printk(KERN_ALERT "*pde = %08lx\n", page);
136 if (page & 1) {
137 page &= PAGE_MASK;
138 address &= 0x003ff000;
139 page = ((unsigned long *) page)[address >> PAGE_SHIFT];
140 printk(KERN_ALERT "*pte = %08lx\n", page);
141 }
142 die_if_kernel("Oops", regs, error_code);
143 do_exit(SIGKILL);
144 }