Merge branch 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull x86 irq updates from Ingo Molnar:
 "Here are the main changes in this tree:

   - Introduce x86-64 IRQ/exception/debug stack guard pages to detect
     stack overflows immediately and deterministically.

   - Clean up over a decade worth of cruft accumulated.

  The outcome of this should be more clear-cut faults/crashes when any
  of the low level x86 CPU stacks overflow, instead of silent memory
  corruption and sporadic failures much later on"

* 'x86-irq-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (33 commits)
  x86/irq: Fix outdated comments
  x86/irq/64: Remove stack overflow debug code
  x86/irq/64: Remap the IRQ stack with guard pages
  x86/irq/64: Split the IRQ stack into its own pages
  x86/irq/64: Init hardirq_stack_ptr during CPU hotplug
  x86/irq/32: Handle irq stack allocation failure proper
  x86/irq/32: Invoke irq_ctx_init() from init_IRQ()
  x86/irq/64: Rename irq_stack_ptr to hardirq_stack_ptr
  x86/irq/32: Rename hard/softirq_stack to hard/softirq_stack_ptr
  x86/irq/32: Make irq stack a character array
  x86/irq/32: Define IRQ_STACK_SIZE
  x86/dumpstack/64: Speedup in_exception_stack()
  x86/exceptions: Split debug IST stack
  x86/exceptions: Enable IST guard pages
  x86/exceptions: Disconnect IST index and stack order
  x86/cpu: Remove orig_ist array
  x86/cpu: Prepare TSS.IST setup for guard pages
  x86/dumpstack/64: Use cpu_entry_area instead of orig_ist
  x86/irq/64: Use cpu entry area instead of orig_ist
  x86/traps: Use cpu_entry_area instead of orig_ist
  ...

1 files changed, 15 insertions, 28 deletions

diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h
index 2bb3a648fc12..7e99ef67bff0 100644
--- a/arch/x86/include/asm/processor.h
+++ b/arch/x86/include/asm/processor.h
@@ -367,6 +367,13 @@ DECLARE_PER_CPU_PAGE_ALIGNED(struct tss_struct, cpu_tss_rw);
 #define __KERNEL_TSS_LIMIT	\
 	(IO_BITMAP_OFFSET + IO_BITMAP_BYTES + sizeof(unsigned long) - 1)
 
+/* Per CPU interrupt stacks */
+struct irq_stack {
+	char		stack[IRQ_STACK_SIZE];
+} __aligned(IRQ_STACK_SIZE);
+
+DECLARE_PER_CPU(struct irq_stack *, hardirq_stack_ptr);
+
 #ifdef CONFIG_X86_32
 DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack);
 #else
@@ -374,38 +381,25 @@ DECLARE_PER_CPU(unsigned long, cpu_current_top_of_stack);
 #define cpu_current_top_of_stack cpu_tss_rw.x86_tss.sp1
 #endif
 
-/*
- * Save the original ist values for checking stack pointers during debugging
- */
-struct orig_ist {
-	unsigned long		ist[7];
-};
-
 #ifdef CONFIG_X86_64
-DECLARE_PER_CPU(struct orig_ist, orig_ist);
-
-union irq_stack_union {
-	char irq_stack[IRQ_STACK_SIZE];
+struct fixed_percpu_data {
 	/*
 	 * GCC hardcodes the stack canary as %gs:40.  Since the
 	 * irq_stack is the object at %gs:0, we reserve the bottom
 	 * 48 bytes of the irq stack for the canary.
 	 */
-	struct {
-		char gs_base[40];
-		unsigned long stack_canary;
-	};
+	char		gs_base[40];
+	unsigned long	stack_canary;
 };
 
-DECLARE_PER_CPU_FIRST(union irq_stack_union, irq_stack_union) __visible;
-DECLARE_INIT_PER_CPU(irq_stack_union);
+DECLARE_PER_CPU_FIRST(struct fixed_percpu_data, fixed_percpu_data) __visible;
+DECLARE_INIT_PER_CPU(fixed_percpu_data);
 
 static inline unsigned long cpu_kernelmode_gs_base(int cpu)
 {
-	return (unsigned long)per_cpu(irq_stack_union.gs_base, cpu);
+	return (unsigned long)per_cpu(fixed_percpu_data.gs_base, cpu);
 }
 
-DECLARE_PER_CPU(char *, irq_stack_ptr);
 DECLARE_PER_CPU(unsigned int, irq_count);
 extern asmlinkage void ignore_sysret(void);
 
@@ -427,15 +421,8 @@ struct stack_canary {
 };
 DECLARE_PER_CPU_ALIGNED(struct stack_canary, stack_canary);
 #endif
-/*
- * per-CPU IRQ handling stacks
- */
-struct irq_stack {
-	u32                     stack[THREAD_SIZE/sizeof(u32)];
-} __aligned(THREAD_SIZE);
-
-DECLARE_PER_CPU(struct irq_stack *, hardirq_stack);
-DECLARE_PER_CPU(struct irq_stack *, softirq_stack);
+/* Per CPU softirq stack pointer */
+DECLARE_PER_CPU(struct irq_stack *, softirq_stack_ptr);
 #endif	/* X86_64 */
 
 extern unsigned int fpu_kernel_xstate_size;