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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /arch/i386/kernel/doublefault.c
downloadlinux-stericsson-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'arch/i386/kernel/doublefault.c')
-rw-r--r--arch/i386/kernel/doublefault.c65
1 files changed, 65 insertions, 0 deletions
diff --git a/arch/i386/kernel/doublefault.c b/arch/i386/kernel/doublefault.c
new file mode 100644
index 000000000000..789af3e9fb1f
--- /dev/null
+++ b/arch/i386/kernel/doublefault.c
@@ -0,0 +1,65 @@
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/init.h>
+#include <linux/init_task.h>
+#include <linux/fs.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/processor.h>
+#include <asm/desc.h>
+
+#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 + 0x1000000)
+
+static void doublefault_fn(void)
+{
+ struct Xgt_desc_struct gdt_desc = {0, 0};
+ unsigned long gdt, tss;
+
+ __asm__ __volatile__("sgdt %0": "=m" (gdt_desc): :"memory");
+ gdt = gdt_desc.address;
+
+ printk("double fault, gdt at %08lx [%d bytes]\n", gdt, gdt_desc.size);
+
+ if (ptr_ok(gdt)) {
+ gdt += GDT_ENTRY_TSS << 3;
+ tss = *(u16 *)(gdt+2);
+ tss += *(u8 *)(gdt+4) << 16;
+ tss += *(u8 *)(gdt+7) << 24;
+ printk("double fault, tss at %08lx\n", tss);
+
+ if (ptr_ok(tss)) {
+ struct tss_struct *t = (struct tss_struct *)tss;
+
+ printk("eip = %08lx, esp = %08lx\n", t->eip, t->esp);
+
+ printk("eax = %08lx, ebx = %08lx, ecx = %08lx, edx = %08lx\n",
+ t->eax, t->ebx, t->ecx, t->edx);
+ printk("esi = %08lx, edi = %08lx\n",
+ t->esi, t->edi);
+ }
+ }
+
+ for (;;) /* nothing */;
+}
+
+struct tss_struct doublefault_tss __cacheline_aligned = {
+ .esp0 = STACK_START,
+ .ss0 = __KERNEL_DS,
+ .ldt = 0,
+ .io_bitmap_base = INVALID_IO_BITMAP_OFFSET,
+
+ .eip = (unsigned long) doublefault_fn,
+ .eflags = X86_EFLAGS_SF | 0x2, /* 0x2 bit is always set */
+ .esp = STACK_START,
+ .es = __USER_DS,
+ .cs = __KERNEL_CS,
+ .ss = __KERNEL_DS,
+ .ds = __USER_DS,
+
+ .__cr3 = __pa(swapper_pg_dir)
+};