[mirror_ubuntu-artful-kernel.git] / arch / x86 / kernel / doublefault.c

#include <linux/mm.h>
#include <linux/sched.h>
#include <linux/sched/debug.h>
#include <linux/init_task.h>
#include <linux/fs.h>

#include <linux/uaccess.h>
#include <asm/pgtable.h>
#include <asm/processor.h>
#include <asm/desc.h>

#ifdef CONFIG_X86_32

#define DOUBLEFAULT_STACKSIZE (1024)
static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)

#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM)

static void doublefault_fn(void)
{
	struct desc_ptr gdt_desc = {0, 0};
	unsigned long gdt, tss;

	native_store_gdt(&gdt_desc);
	gdt = gdt_desc.address;

	printk(KERN_EMERG "PANIC: double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);

	if (ptr_ok(gdt)) {
		gdt += GDT_ENTRY_TSS << 3;
		tss = get_desc_base((struct desc_struct *)gdt);
		printk(KERN_EMERG "double fault, tss at %08lx\n", tss);

		if (ptr_ok(tss)) {
			struct x86_hw_tss *t = (struct x86_hw_tss *)tss;

			printk(KERN_EMERG "eip = %08lx, esp = %08lx\n",
			       t->ip, t->sp);

			printk(KERN_EMERG "eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
				t->ax, t->bx, t->cx, t->dx);
			printk(KERN_EMERG "esi = %08lx, edi = %08lx\n",
				t->si, t->di);
		}
	}

	for (;;)
		cpu_relax();
}

struct tss_struct doublefault_tss __cacheline_aligned = {
	.x86_tss = {
		.sp0		= STACK_START,
		.ss0		= __KERNEL_DS,
		.ldt		= 0,
		.io_bitmap_base	= INVALID_IO_BITMAP_OFFSET,

		.ip		= (unsigned long) doublefault_fn,
		/* 0x2 bit is always set */
		.flags		= X86_EFLAGS_SF | 0x2,
		.sp		= STACK_START,
		.es		= __USER_DS,
		.cs		= __KERNEL_CS,
		.ss		= __KERNEL_DS,
		.ds		= __USER_DS,
		.fs		= __KERNEL_PERCPU,

		.__cr3		= __pa_nodebug(swapper_pg_dir),
	}
};

/* dummy for do_double_fault() call */
void df_debug(struct pt_regs *regs, long error_code) {}

#else /* !CONFIG_X86_32 */

void df_debug(struct pt_regs *regs, long error_code)
{
	pr_emerg("PANIC: double fault, error_code: 0x%lx\n", error_code);
	show_regs(regs);
	panic("Machine halted.");
}
#endif
Commit	Line	Data
1da177e4 LT	1	#include <linux/mm.h>
1da177e4 LT	2	#include <linux/sched.h>
b17b0153	3	#include <linux/sched/debug.h>
1da177e4 LT	4	#include <linux/init_task.h>
	5	#include <linux/fs.h>
	6
7c0f6ba6	7	#include <linux/uaccess.h>
1da177e4 LT	8	#include <asm/pgtable.h>
	9	#include <asm/processor.h>
	10	#include <asm/desc.h>
	11
4d067d8e BP	12	#ifdef CONFIG_X86_32
4d067d8e BP	13
1da177e4 LT	14	#define DOUBLEFAULT_STACKSIZE (1024)
	15	static unsigned long doublefault_stack[DOUBLEFAULT_STACKSIZE];
	16	#define STACK_START (unsigned long)(doublefault_stack+DOUBLEFAULT_STACKSIZE)
	17
3dab307e	18	#define ptr_ok(x) ((x) > PAGE_OFFSET && (x) < PAGE_OFFSET + MAXMEM)
1da177e4 LT	19
	20	static void doublefault_fn(void)
	21	{
6b68f01b	22	struct desc_ptr gdt_desc = {0, 0};
1da177e4 LT	23	unsigned long gdt, tss;
1da177e4 LT	24
357d1226	25	native_store_gdt(&gdt_desc);
1da177e4 LT	26	gdt = gdt_desc.address;
1da177e4 LT	27
3dab307e	28	printk(KERN_EMERG "PANIC: double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
1da177e4 LT	29
	30	if (ptr_ok(gdt)) {
	31	gdt += GDT_ENTRY_TSS << 3;
254e0a6b	32	tss = get_desc_base((struct desc_struct *)gdt);
3dab307e	33	printk(KERN_EMERG "double fault, tss at %08lx\n", tss);
1da177e4 LT	34
1da177e4 LT	35	if (ptr_ok(tss)) {
ca241c75	36	struct x86_hw_tss t = (struct x86_hw_tss )tss;
1da177e4	37
faca6227 PA	38	printk(KERN_EMERG "eip = %08lx, esp = %08lx\n",
faca6227 PA	39	t->ip, t->sp);
1da177e4	40
3dab307e	41	printk(KERN_EMERG "eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
faca6227	42	t->ax, t->bx, t->cx, t->dx);
3dab307e	43	printk(KERN_EMERG "esi = %08lx, edi = %08lx\n",
faca6227	44	t->si, t->di);
1da177e4 LT	45	}
	46	}
	47
caad3c2a CE	48	for (;;)
caad3c2a CE	49	cpu_relax();
1da177e4 LT	50	}
	51
	52	struct tss_struct doublefault_tss __cacheline_aligned = {
a75c54f9	53	.x86_tss = {
faca6227	54	.sp0 = STACK_START,
a75c54f9 RR	55	.ss0 = __KERNEL_DS,
	56	.ldt = 0,
	57	.io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
1da177e4	58
faca6227	59	.ip = (unsigned long) doublefault_fn,
a75c54f9	60	/* 0x2 bit is always set */
faca6227 PA	61	.flags = X86_EFLAGS_SF \| 0x2,
faca6227 PA	62	.sp = STACK_START,
a75c54f9 RR	63	.es = __USER_DS,
	64	.cs = __KERNEL_CS,
	65	.ss = __KERNEL_DS,
	66	.ds = __USER_DS,
3dab307e	67	.fs = __KERNEL_PERCPU,
1da177e4	68
af5c2bd1	69	.__cr3 = __pa_nodebug(swapper_pg_dir),
a75c54f9	70	}
1da177e4	71	};
4d067d8e BP	72
	73	/* dummy for do_double_fault() call */
	74	void df_debug(struct pt_regs *regs, long error_code) {}
	75
	76	#else /* !CONFIG_X86_32 */
	77
	78	void df_debug(struct pt_regs *regs, long error_code)
	79	{
	80	pr_emerg("PANIC: double fault, error_code: 0x%lx\n", error_code);
	81	show_regs(regs);
	82	panic("Machine halted.");
	83	}
	84	#endif