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/arch/x86/kernel/doublefault_32.c

https://gitlab.com/Team-OSE-old/SimpleKernel
C | 69 lines | 54 code | 14 blank | 1 comment | 4 complexity | c5c28f6cd1559a91c790acbe96cb7c8b MD5 | raw file
 1#include <linux/mm.h>
 2#include <linux/sched.h>
 3#include <linux/init.h>
 4#include <linux/init_task.h>
 5#include <linux/fs.h>
 6
 7#include <asm/uaccess.h>
 8#include <asm/pgtable.h>
 9#include <asm/processor.h>
10#include <asm/desc.h>
11
12#define DOUBLEFAULT_STACKSIZE (1024)
13static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
14#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
15
16#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM)
17
18static void doublefault_fn(void)
19{
20	struct desc_ptr gdt_desc = {0, 0};
21	unsigned long gdt, tss;
22
23	store_gdt(&gdt_desc);
24	gdt = gdt_desc.address;
25
26	printk(KERN_EMERG "PANIC: double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
27
28	if (ptr_ok(gdt)) {
29		gdt += GDT_ENTRY_TSS << 3;
30		tss = get_desc_base((struct desc_struct *)gdt);
31		printk(KERN_EMERG "double fault, tss at %08lx\n", tss);
32
33		if (ptr_ok(tss)) {
34			struct x86_hw_tss *t = (struct x86_hw_tss *)tss;
35
36			printk(KERN_EMERG "eip = %08lx, esp = %08lx\n",
37			       t->ip, t->sp);
38
39			printk(KERN_EMERG "eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
40				t->ax, t->bx, t->cx, t->dx);
41			printk(KERN_EMERG "esi = %08lx, edi = %08lx\n",
42				t->si, t->di);
43		}
44	}
45
46	for (;;)
47		cpu_relax();
48}
49
50struct tss_struct doublefault_tss __cacheline_aligned = {
51	.x86_tss = {
52		.sp0		= STACK_START,
53		.ss0		= __KERNEL_DS,
54		.ldt		= 0,
55		.io_bitmap_base	= INVALID_IO_BITMAP_OFFSET,
56
57		.ip		= (unsigned long) doublefault_fn,
58		/* 0x2 bit is always set */
59		.flags		= X86_EFLAGS_SF | 0x2,
60		.sp		= STACK_START,
61		.es		= __USER_DS,
62		.cs		= __KERNEL_CS,
63		.ss		= __KERNEL_DS,
64		.ds		= __USER_DS,
65		.fs		= __KERNEL_PERCPU,
66
67		.__cr3		= __pa_nodebug(swapper_pg_dir),
68	}
69};