Merge commit 'remotes/tip/x86/paravirt' into x86/untangle2

[pandora-kernel.git] / arch / x86 / kernel / process_64.c

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index c958120..c422eeb 100644 (file)
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -16,6 +16,7 @@
 
 #include <stdarg.h>
 
+#include <linux/stackprotector.h>
 #include <linux/cpu.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
@@ -39,22 +40,29 @@
 #include <linux/prctl.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
+#include <linux/ftrace.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
 #include <asm/processor.h>
 #include <asm/i387.h>
 #include <asm/mmu_context.h>
-#include <asm/pda.h>
 #include <asm/prctl.h>
 #include <asm/desc.h>
 #include <asm/proto.h>
 #include <asm/ia32.h>
 #include <asm/idle.h>
 #include <asm/syscalls.h>
+#include <asm/ds.h>
 
 asmlinkage extern void ret_from_fork(void);
 
+DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
+EXPORT_PER_CPU_SYMBOL(current_task);
+
+DEFINE_PER_CPU(unsigned long, old_rsp);
+static DEFINE_PER_CPU(unsigned char, is_idle);
+
 unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED;
 
 static ATOMIC_NOTIFIER_HEAD(idle_notifier);
@@ -73,13 +81,13 @@ EXPORT_SYMBOL_GPL(idle_notifier_unregister);
 
 void enter_idle(void)
 {
-       write_pda(isidle, 1);
+       percpu_write(is_idle, 1);
        atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
 }
 
 static void __exit_idle(void)
 {
-       if (test_and_clear_bit_pda(0, isidle) == 0)
+       if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
                return;
        atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL);
 }
@@ -109,6 +117,17 @@ static inline void play_dead(void)
 void cpu_idle(void)
 {
        current_thread_info()->status |= TS_POLLING;
+
+       /*
+        * If we're the non-boot CPU, nothing set the PDA stack
+        * canary up for us - and if we are the boot CPU we have
+        * a 0 stack canary. This is a good place for updating
+        * it, as we wont ever return from this function (so the
+        * invalid canaries already on the stack wont ever
+        * trigger):
+        */
+       boot_init_stack_canary();
+
        /* endless idle loop with no priority at all */
        while (1) {
                tick_nohz_stop_sched_tick(1);
@@ -235,14 +254,8 @@ void exit_thread(void)
                t->io_bitmap_max = 0;
                put_cpu();
        }
-#ifdef CONFIG_X86_DS
-       /* Free any DS contexts that have not been properly released. */
-       if (unlikely(t->ds_ctx)) {
-               /* we clear debugctl to make sure DS is not used. */
-               update_debugctlmsr(0);
-               ds_free(t->ds_ctx);
-       }
-#endif /* CONFIG_X86_DS */
+
+       ds_exit_thread(current);
 }
 
 void flush_thread(void)
@@ -372,6 +385,12 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
                if (err)
                        goto out;
        }
+
+       ds_copy_thread(p, me);
+
+       clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
+       p->thread.debugctlmsr = 0;
+
        err = 0;
 out:
        if (err && p->thread.io_bitmap_ptr) {
@@ -390,7 +409,7 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
        load_gs_index(0);
        regs->ip                = new_ip;
        regs->sp                = new_sp;
-       write_pda(oldrsp, new_sp);
+       percpu_write(old_rsp, new_sp);
        regs->cs                = __USER_CS;
        regs->ss                = __USER_DS;
        regs->flags             = 0x200;
@@ -470,35 +489,14 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
                                    struct tss_struct *tss)
 {
        struct thread_struct *prev, *next;
-       unsigned long debugctl;
 
        prev = &prev_p->thread,
        next = &next_p->thread;
 
-       debugctl = prev->debugctlmsr;
-
-#ifdef CONFIG_X86_DS
-       {
-               unsigned long ds_prev = 0, ds_next = 0;
-
-               if (prev->ds_ctx)
-                       ds_prev = (unsigned long)prev->ds_ctx->ds;
-               if (next->ds_ctx)
-                       ds_next = (unsigned long)next->ds_ctx->ds;
-
-               if (ds_next != ds_prev) {
-                       /*
-                        * We clear debugctl to make sure DS
-                        * is not in use when we change it:
-                        */
-                       debugctl = 0;
-                       update_debugctlmsr(0);
-                       wrmsrl(MSR_IA32_DS_AREA, ds_next);
-               }
-       }
-#endif /* CONFIG_X86_DS */
-
-       if (next->debugctlmsr != debugctl)
+       if (test_tsk_thread_flag(next_p, TIF_DS_AREA_MSR) ||
+           test_tsk_thread_flag(prev_p, TIF_DS_AREA_MSR))
+               ds_switch_to(prev_p, next_p);
+       else if (next->debugctlmsr != prev->debugctlmsr)
                update_debugctlmsr(next->debugctlmsr);
 
        if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
@@ -533,14 +531,6 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
                 */
                memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
        }
-
-#ifdef CONFIG_X86_PTRACE_BTS
-       if (test_tsk_thread_flag(prev_p, TIF_BTS_TRACE_TS))
-               ptrace_bts_take_timestamp(prev_p, BTS_TASK_DEPARTS);
-
-       if (test_tsk_thread_flag(next_p, TIF_BTS_TRACE_TS))
-               ptrace_bts_take_timestamp(next_p, BTS_TASK_ARRIVES);
-#endif /* CONFIG_X86_PTRACE_BTS */
 }
 
 /*
@@ -551,8 +541,9 @@ static inline void __switch_to_xtra(struct task_struct *prev_p,
  * - could test fs/gs bitsliced
  *
  * Kprobes not supported here. Set the probe on schedule instead.
+ * Function graph tracer not supported too.
  */
-struct task_struct *
+__notrace_funcgraph struct task_struct *
 __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
 {
        struct thread_struct *prev = &prev_p->thread;
@@ -639,21 +630,13 @@ __switch_to(struct task_struct *prev_p, struct task_struct *next_p)
        /*
         * Switch the PDA and FPU contexts.
         */
-       prev->usersp = read_pda(oldrsp);
-       write_pda(oldrsp, next->usersp);
-       write_pda(pcurrent, next_p);
+       prev->usersp = percpu_read(old_rsp);
+       percpu_write(old_rsp, next->usersp);
+       percpu_write(current_task, next_p);
 
-       write_pda(kernelstack,
+       percpu_write(kernel_stack,
                  (unsigned long)task_stack_page(next_p) +
-                 THREAD_SIZE - PDA_STACKOFFSET);
-#ifdef CONFIG_CC_STACKPROTECTOR
-       write_pda(stack_canary, next_p->stack_canary);
-       /*
-        * Build time only check to make sure the stack_canary is at
-        * offset 40 in the pda; this is a gcc ABI requirement
-        */
-       BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40);
-#endif
+                 THREAD_SIZE - KERNEL_STACK_OFFSET);
 
        /*
         * Now maybe reload the debug registers and handle I/O bitmaps