70 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			70 lines
		
	
	
		
			1.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/init.h>
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#include <linux/init_task.h>
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#include <linux/fs.h>
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#include <asm/uaccess.h>
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#include <asm/pgtable.h>
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#include <asm/processor.h>
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#include <asm/desc.h>
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#define DOUBLEFAULT_STACKSIZE (1024)
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static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
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#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
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#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM)
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static void doublefault_fn(void)
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{
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	struct desc_ptr gdt_desc = {0, 0};
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	unsigned long gdt, tss;
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	store_gdt(&gdt_desc);
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	gdt = gdt_desc.address;
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	printk(KERN_EMERG "PANIC: double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
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	if (ptr_ok(gdt)) {
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		gdt += GDT_ENTRY_TSS << 3;
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		tss = get_desc_base((struct desc_struct *)gdt);
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		printk(KERN_EMERG "double fault, tss at %08lx\n", tss);
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		if (ptr_ok(tss)) {
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			struct x86_hw_tss *t = (struct x86_hw_tss *)tss;
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			printk(KERN_EMERG "eip = %08lx, esp = %08lx\n",
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			       t->ip, t->sp);
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			printk(KERN_EMERG "eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
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				t->ax, t->bx, t->cx, t->dx);
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			printk(KERN_EMERG "esi = %08lx, edi = %08lx\n",
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				t->si, t->di);
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		}
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	}
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	for (;;)
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		cpu_relax();
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}
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struct tss_struct doublefault_tss __cacheline_aligned = {
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	.x86_tss = {
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		.sp0		= STACK_START,
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		.ss0		= __KERNEL_DS,
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		.ldt		= 0,
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		.io_bitmap_base	= INVALID_IO_BITMAP_OFFSET,
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		.ip		= (unsigned long) doublefault_fn,
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		/* 0x2 bit is always set */
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		.flags		= X86_EFLAGS_SF | 0x2,
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		.sp		= STACK_START,
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		.es		= __USER_DS,
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		.cs		= __KERNEL_CS,
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		.ss		= __KERNEL_DS,
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		.ds		= __USER_DS,
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		.fs		= __KERNEL_PERCPU,
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		.__cr3		= __pa_nodebug(swapper_pg_dir),
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	}
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};
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