1 files changed, 20 insertions, 6 deletions

diff --git a/include/asm-i386/processor.h b/include/asm-i386/processor.h
index 5c96cf6dcb39..feca5d961e2b 100644
--- a/include/asm-i386/processor.h
+++ b/include/asm-i386/processor.h
@@ -61,9 +61,11 @@ struct cpuinfo_x86 {
         int     x86_cache_size;  /* in KB - valid for CPUS which support this
                                     call  */
         int     x86_cache_alignment;    /* In bytes */
-        int     fdiv_bug;
-        int     f00f_bug;
-        int     coma_bug;
+        char    fdiv_bug;
+        char    f00f_bug;
+        char    coma_bug;
+        char    pad0;
+        int     x86_power;
         unsigned long loops_per_jiffy;
         unsigned char x86_max_cores;    /* cpuid returned max cores value */
         unsigned char booted_cores;     /* number of cores as seen by OS */
@@ -279,9 +281,11 @@ static inline void clear_in_cr4 (unsigned long mask)
         outb((data), 0x23); \
 } while (0)
 
-static inline void serialize_cpu(void)
+/* Stop speculative execution */
+static inline void sync_core(void)
 {
-         __asm__ __volatile__ ("cpuid" : : : "ax", "bx", "cx", "dx");
+        int tmp;
+        asm volatile("cpuid" : "=a" (tmp) : "0" (1) : "ebx","ecx","edx","memory");
 }
 
 static inline void __monitor(const void *eax, unsigned long ecx,
@@ -557,10 +561,20 @@ unsigned long get_wchan(struct task_struct *p);
        (unsigned long)(&__ptr[THREAD_SIZE_LONGS]);                     \
 })
 
+/*
+ * 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.
+ */
 #define task_pt_regs(task)                                             \
 ({                                                                     \
        struct pt_regs *__regs__;                                       \
-       __regs__ = (struct pt_regs *)KSTK_TOP((task)->thread_info);     \
+       __regs__ = (struct pt_regs *)(KSTK_TOP(task_stack_page(task))-8); \
        __regs__ - 1;                                                   \
 })