patch-2.4.20 linux-2.4.20/arch/i386/kernel/traps.c

• Lines: 98
• Date: Thu Nov 28 15:53:09 2002
• Orig file: linux-2.4.19/arch/i386/kernel/traps.c
• Orig date: Fri Aug 2 17:39:42 2002

diff -urN linux-2.4.19/arch/i386/kernel/traps.c linux-2.4.20/arch/i386/kernel/traps.c
@@ -40,9 +40,9 @@
 
 #include <asm/smp.h>
 #include <asm/pgalloc.h>
+#include <asm/fixmap.h>
 
 #ifdef CONFIG_X86_VISWS_APIC
-#include <asm/fixmap.h>
 #include <asm/cobalt.h>
 #include <asm/lithium.h>
 #endif
@@ -186,6 +186,14 @@
 	show_trace(esp);
 }
 
+/*
+ * The architecture-independent backtrace generator
+ */
+void dump_stack(void)
+{
+	show_stack(0);
+}
+
 void show_registers(struct pt_regs *regs)
 {
 	int i;
@@ -305,8 +313,13 @@
 static void inline do_trap(int trapnr, int signr, char *str, int vm86,
 			   struct pt_regs * regs, long error_code, siginfo_t *info)
 {
-	if (vm86 && regs->eflags & VM_MASK)
-		goto vm86_trap;
+	if (regs->eflags & VM_MASK) {
+		if (vm86)
+			goto vm86_trap;
+		else
+			goto trap_signal;
+	}
+
 	if (!(regs->xcs & 3))
 		goto kernel_trap;
 
@@ -514,10 +527,15 @@
 {
 	unsigned int condition;
 	struct task_struct *tsk = current;
+	unsigned long eip = regs->eip;
 	siginfo_t info;
 
 	__asm__ __volatile__("movl %%db6,%0" : "=r" (condition));
 
+	/* If the user set TF, it's simplest to clear it right away. */
+	if ((eip >=PAGE_OFFSET) && (regs->eflags & TF_MASK))
+		goto clear_TF;
+
 	/* Mask out spurious debug traps due to lazy DR7 setting */
 	if (condition & (DR_TRAP0|DR_TRAP1|DR_TRAP2|DR_TRAP3)) {
 		if (!tsk->thread.debugreg[7])
@@ -758,35 +776,17 @@
 
 #endif /* CONFIG_MATH_EMULATION */
 
-#ifndef CONFIG_M686
+#ifndef CONFIG_X86_F00F_WORKS_OK
 void __init trap_init_f00f_bug(void)
 {
-	unsigned long page;
-	pgd_t * pgd;
-	pmd_t * pmd;
-	pte_t * pte;
-
-	/*
-	 * Allocate a new page in virtual address space, 
-	 * move the IDT into it and write protect this page.
-	 */
-	page = (unsigned long) vmalloc(PAGE_SIZE);
-	pgd = pgd_offset(&init_mm, page);
-	pmd = pmd_offset(pgd, page);
-	pte = pte_offset(pmd, page);
-	__free_page(pte_page(*pte));
-	*pte = mk_pte_phys(__pa(&idt_table), PAGE_KERNEL_RO);
-	/*
-	 * Not that any PGE-capable kernel should have the f00f bug ...
-	 */
-	__flush_tlb_all();
-
 	/*
 	 * "idt" is magic - it overlaps the idt_descr
 	 * variable so that updating idt will automatically
 	 * update the idt descriptor..
 	 */
-	idt = (struct desc_struct *)page;
+	__set_fixmap(FIX_F00F, __pa(&idt_table), PAGE_KERNEL_RO);
+	idt = (struct desc_struct *)__fix_to_virt(FIX_F00F);
+
 	__asm__ __volatile__("lidt %0": "=m" (idt_descr));
 }
 #endif