1 files changed, 8 insertions, 35 deletions

diff --git a/arch/i386/kernel/process.c b/arch/i386/kernel/process.c
index 2333aead056..2185377fdde 100644
--- a/arch/i386/kernel/process.c
+++ b/arch/i386/kernel/process.c
@@ -48,6 +48,7 @@
 #include <asm/processor.h>
 #include <asm/i387.h>
 #include <asm/desc.h>
+#include <asm/vm86.h>
 #ifdef CONFIG_MATH_EMULATION
 #include <asm/math_emu.h>
 #endif
@@ -308,9 +309,7 @@ void show_regs(struct pt_regs * regs)
 	cr0 = read_cr0();
 	cr2 = read_cr2();
 	cr3 = read_cr3();
-	if (current_cpu_data.x86 > 4) {
-		cr4 = read_cr4();
-	}
+	cr4 = read_cr4_safe();
 	printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
 	show_trace(NULL, &regs->esp);
 }
@@ -404,17 +403,7 @@ void flush_thread(void)
 
 void release_thread(struct task_struct *dead_task)
 {
-	if (dead_task->mm) {
-		// temporary debugging check
-		if (dead_task->mm->context.size) {
-			printk("WARNING: dead process %8s still has LDT? <%p/%d>\n",
-					dead_task->comm,
-					dead_task->mm->context.ldt,
-					dead_task->mm->context.size);
-			BUG();
-		}
-	}
-
+	BUG_ON(dead_task->mm);
 	release_vm86_irqs(dead_task);
 }
 
@@ -435,18 +424,7 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long esp,
 	struct task_struct *tsk;
 	int err;
 
-	childregs = ((struct pt_regs *) (THREAD_SIZE + (unsigned long) p->thread_info)) - 1;
-	/*
-	 * The below -8 is to reserve 8 bytes on top of the ring0 stack.
-	 * This is necessary to guarantee that the entire "struct pt_regs"
-	 * is accessable even if the CPU haven't stored the SS/ESP registers
-	 * on the stack (interrupt gate does not save these registers
-	 * when switching to the same priv ring).
-	 * Therefore beware: accessing the xss/esp fields of the
-	 * "struct pt_regs" is possible, but they may contain the
-	 * completely wrong values.
-	 */
-	childregs = (struct pt_regs *) ((unsigned long) childregs - 8);
+	childregs = task_pt_regs(p);
 	*childregs = *regs;
 	childregs->eax = 0;
 	childregs->esp = esp;
@@ -551,12 +529,7 @@ EXPORT_SYMBOL(dump_thread);
  */
 int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs)
 {
-	struct pt_regs ptregs;
-	
-	ptregs = *(struct pt_regs *)
-		((unsigned long)tsk->thread_info +
-		/* see comments in copy_thread() about -8 */
-		THREAD_SIZE - sizeof(ptregs) - 8);
+	struct pt_regs ptregs = *task_pt_regs(tsk);
 	ptregs.xcs &= 0xffff;
 	ptregs.xds &= 0xffff;
 	ptregs.xes &= 0xffff;
@@ -612,8 +585,8 @@ static inline void disable_tsc(struct task_struct *prev_p,
 	 * gcc should eliminate the ->thread_info dereference if
 	 * has_secure_computing returns 0 at compile time (SECCOMP=n).
 	 */
-	prev = prev_p->thread_info;
-	next = next_p->thread_info;
+	prev = task_thread_info(prev_p);
+	next = task_thread_info(next_p);
 
 	if (has_secure_computing(prev) || has_secure_computing(next)) {
 		/* slow path here */
@@ -798,7 +771,7 @@ unsigned long get_wchan(struct task_struct *p)
 	int count = 0;
 	if (!p || p == current || p->state == TASK_RUNNING)
 		return 0;
-	stack_page = (unsigned long)p->thread_info;
+	stack_page = (unsigned long)task_stack_page(p);
 	esp = p->thread.esp;
 	if (!stack_page || esp < stack_page || esp > top_esp+stack_page)
 		return 0;