1 files changed, 25 insertions, 205 deletions

diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index 85b4cb5c1980..abb7e6a7f0c6 100644
--- 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>
@@ -47,7 +48,6 @@
 #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>
@@ -58,6 +58,12 @@
 
 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);
@@ -76,13 +82,13 @@ 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);
 }
@@ -112,6 +118,16 @@ 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 stack canary up
+         * for us.  CPU0 already has it initialized but no harm in
+         * doing it again.  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);
@@ -221,61 +237,6 @@ void show_regs(struct pt_regs *regs)
         show_trace(NULL, regs, (void *)(regs + 1), regs->bp);
 }
 
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
-        struct task_struct *me = current;
-        struct thread_struct *t = &me->thread;
-
-        if (me->thread.io_bitmap_ptr) {
-                struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
-
-                kfree(t->io_bitmap_ptr);
-                t->io_bitmap_ptr = NULL;
-                clear_thread_flag(TIF_IO_BITMAP);
-                /*
-                 * Careful, clear this in the TSS too:
-                 */
-                memset(tss->io_bitmap, 0xff, t->io_bitmap_max);
-                t->io_bitmap_max = 0;
-                put_cpu();
-        }
-
-        ds_exit_thread(current);
-}
-
-void flush_thread(void)
-{
-        struct task_struct *tsk = current;
-
-        if (test_tsk_thread_flag(tsk, TIF_ABI_PENDING)) {
-                clear_tsk_thread_flag(tsk, TIF_ABI_PENDING);
-                if (test_tsk_thread_flag(tsk, TIF_IA32)) {
-                        clear_tsk_thread_flag(tsk, TIF_IA32);
-                } else {
-                        set_tsk_thread_flag(tsk, TIF_IA32);
-                        current_thread_info()->status |= TS_COMPAT;
-                }
-        }
-        clear_tsk_thread_flag(tsk, TIF_DEBUG);
-
-        tsk->thread.debugreg0 = 0;
-        tsk->thread.debugreg1 = 0;
-        tsk->thread.debugreg2 = 0;
-        tsk->thread.debugreg3 = 0;
-        tsk->thread.debugreg6 = 0;
-        tsk->thread.debugreg7 = 0;
-        memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
-        /*
-         * Forget coprocessor state..
-         */
-        tsk->fpu_counter = 0;
-        clear_fpu(tsk);
-        clear_used_math();
-}
-
 void release_thread(struct task_struct *dead_task)
 {
         if (dead_task->mm) {
@@ -397,7 +358,7 @@ 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;
@@ -409,118 +370,6 @@ start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
 }
 EXPORT_SYMBOL_GPL(start_thread);
 
-static void hard_disable_TSC(void)
-{
-        write_cr4(read_cr4() | X86_CR4_TSD);
-}
-
-void disable_TSC(void)
-{
-        preempt_disable();
-        if (!test_and_set_thread_flag(TIF_NOTSC))
-                /*
-                 * Must flip the CPU state synchronously with
-                 * TIF_NOTSC in the current running context.
-                 */
-                hard_disable_TSC();
-        preempt_enable();
-}
-
-static void hard_enable_TSC(void)
-{
-        write_cr4(read_cr4() & ~X86_CR4_TSD);
-}
-
-static void enable_TSC(void)
-{
-        preempt_disable();
-        if (test_and_clear_thread_flag(TIF_NOTSC))
-                /*
-                 * Must flip the CPU state synchronously with
-                 * TIF_NOTSC in the current running context.
-                 */
-                hard_enable_TSC();
-        preempt_enable();
-}
-
-int get_tsc_mode(unsigned long adr)
-{
-        unsigned int val;
-
-        if (test_thread_flag(TIF_NOTSC))
-                val = PR_TSC_SIGSEGV;
-        else
-                val = PR_TSC_ENABLE;
-
-        return put_user(val, (unsigned int __user *)adr);
-}
-
-int set_tsc_mode(unsigned int val)
-{
-        if (val == PR_TSC_SIGSEGV)
-                disable_TSC();
-        else if (val == PR_TSC_ENABLE)
-                enable_TSC();
-        else
-                return -EINVAL;
-
-        return 0;
-}
-
-/*
- * This special macro can be used to load a debugging register
- */
-#define loaddebug(thread, r) set_debugreg(thread->debugreg ## r, r)
-
-static inline void __switch_to_xtra(struct task_struct *prev_p,
-                                    struct task_struct *next_p,
-                                    struct tss_struct *tss)
-{
-        struct thread_struct *prev, *next;
-
-        prev = &prev_p->thread,
-        next = &next_p->thread;
-
-        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)) {
-                loaddebug(next, 0);
-                loaddebug(next, 1);
-                loaddebug(next, 2);
-                loaddebug(next, 3);
-                /* no 4 and 5 */
-                loaddebug(next, 6);
-                loaddebug(next, 7);
-        }
-
-        if (test_tsk_thread_flag(prev_p, TIF_NOTSC) ^
-            test_tsk_thread_flag(next_p, TIF_NOTSC)) {
-                /* prev and next are different */
-                if (test_tsk_thread_flag(next_p, TIF_NOTSC))
-                        hard_disable_TSC();
-                else
-                        hard_enable_TSC();
-        }
-
-        if (test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
-                /*
-                 * Copy the relevant range of the IO bitmap.
-                 * Normally this is 128 bytes or less:
-                 */
-                memcpy(tss->io_bitmap, next->io_bitmap_ptr,
-                       max(prev->io_bitmap_max, next->io_bitmap_max));
-        } else if (test_tsk_thread_flag(prev_p, TIF_IO_BITMAP)) {
-                /*
-                 * Clear any possible leftover bits:
-                 */
-                memset(tss->io_bitmap, 0xff, prev->io_bitmap_max);
-        }
-}
-
 /*
  *      switch_to(x,y) should switch tasks from x to y.
  *
@@ -618,21 +467,13 @@ __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
@@ -686,11 +527,6 @@ void set_personality_64bit(void)
         current->personality &= ~READ_IMPLIES_EXEC;
 }
 
-asmlinkage long sys_fork(struct pt_regs *regs)
-{
-        return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
-}
-
 asmlinkage long
 sys_clone(unsigned long clone_flags, unsigned long newsp,
           void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
@@ -700,22 +536,6 @@ sys_clone(unsigned long clone_flags, unsigned long newsp,
         return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
 }
 
-/*
- * This is trivial, and on the face of it looks like it
- * could equally well be done in user mode.
- *
- * Not so, for quite unobvious reasons - register pressure.
- * In user mode vfork() cannot have a stack frame, and if
- * done by calling the "clone()" system call directly, you
- * do not have enough call-clobbered registers to hold all
- * the information you need.
- */
-asmlinkage long sys_vfork(struct pt_regs *regs)
-{
-        return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
-                    NULL, NULL);
-}
-
 unsigned long get_wchan(struct task_struct *p)
 {
         unsigned long stack;