summaryrefslogtreecommitdiff
path: root/arch/x86/kernel/process.c
diff options
context:
space:
mode:
authorSrikant Patnaik2015-01-11 12:28:04 +0530
committerSrikant Patnaik2015-01-11 12:28:04 +0530
commit871480933a1c28f8a9fed4c4d34d06c439a7a422 (patch)
tree8718f573808810c2a1e8cb8fb6ac469093ca2784 /arch/x86/kernel/process.c
parent9d40ac5867b9aefe0722bc1f110b965ff294d30d (diff)
downloadFOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.gz
FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.tar.bz2
FOSSEE-netbook-kernel-source-871480933a1c28f8a9fed4c4d34d06c439a7a422.zip
Moved, renamed, and deleted files
The original directory structure was scattered and unorganized. Changes are basically to make it look like kernel structure.
Diffstat (limited to 'arch/x86/kernel/process.c')
-rw-r--r--arch/x86/kernel/process.c745
1 files changed, 745 insertions, 0 deletions
diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c
new file mode 100644
index 00000000..fdd151ce
--- /dev/null
+++ b/arch/x86/kernel/process.c
@@ -0,0 +1,745 @@
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/prctl.h>
+#include <linux/slab.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+#include <linux/pm.h>
+#include <linux/clockchips.h>
+#include <linux/random.h>
+#include <linux/user-return-notifier.h>
+#include <linux/dmi.h>
+#include <linux/utsname.h>
+#include <linux/stackprotector.h>
+#include <linux/tick.h>
+#include <linux/cpuidle.h>
+#include <trace/events/power.h>
+#include <linux/hw_breakpoint.h>
+#include <asm/cpu.h>
+#include <asm/apic.h>
+#include <asm/syscalls.h>
+#include <asm/idle.h>
+#include <asm/uaccess.h>
+#include <asm/i387.h>
+#include <asm/fpu-internal.h>
+#include <asm/debugreg.h>
+#include <asm/nmi.h>
+
+#ifdef CONFIG_X86_64
+static DEFINE_PER_CPU(unsigned char, is_idle);
+#endif
+
+struct kmem_cache *task_xstate_cachep;
+EXPORT_SYMBOL_GPL(task_xstate_cachep);
+
+int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
+{
+ int ret;
+
+ *dst = *src;
+ if (fpu_allocated(&src->thread.fpu)) {
+ memset(&dst->thread.fpu, 0, sizeof(dst->thread.fpu));
+ ret = fpu_alloc(&dst->thread.fpu);
+ if (ret)
+ return ret;
+ fpu_copy(&dst->thread.fpu, &src->thread.fpu);
+ }
+ return 0;
+}
+
+void free_thread_xstate(struct task_struct *tsk)
+{
+ fpu_free(&tsk->thread.fpu);
+}
+
+void free_thread_info(struct thread_info *ti)
+{
+ free_thread_xstate(ti->task);
+ free_pages((unsigned long)ti, THREAD_ORDER);
+}
+
+void arch_task_cache_init(void)
+{
+ task_xstate_cachep =
+ kmem_cache_create("task_xstate", xstate_size,
+ __alignof__(union thread_xstate),
+ SLAB_PANIC | SLAB_NOTRACK, NULL);
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+ struct task_struct *me = current;
+ struct thread_struct *t = &me->thread;
+ unsigned long *bp = t->io_bitmap_ptr;
+
+ if (bp) {
+ struct tss_struct *tss = &per_cpu(init_tss, get_cpu());
+
+ 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();
+ kfree(bp);
+ }
+}
+
+void show_regs(struct pt_regs *regs)
+{
+ show_registers(regs);
+ show_trace(NULL, regs, (unsigned long *)kernel_stack_pointer(regs), 0);
+}
+
+void show_regs_common(void)
+{
+ const char *vendor, *product, *board;
+
+ vendor = dmi_get_system_info(DMI_SYS_VENDOR);
+ if (!vendor)
+ vendor = "";
+ product = dmi_get_system_info(DMI_PRODUCT_NAME);
+ if (!product)
+ product = "";
+
+ /* Board Name is optional */
+ board = dmi_get_system_info(DMI_BOARD_NAME);
+
+ printk(KERN_CONT "\n");
+ printk(KERN_DEFAULT "Pid: %d, comm: %.20s %s %s %.*s",
+ current->pid, current->comm, print_tainted(),
+ init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+ printk(KERN_CONT " %s %s", vendor, product);
+ if (board)
+ printk(KERN_CONT "/%s", board);
+ printk(KERN_CONT "\n");
+}
+
+void flush_thread(void)
+{
+ struct task_struct *tsk = current;
+
+ flush_ptrace_hw_breakpoint(tsk);
+ memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
+ /*
+ * Forget coprocessor state..
+ */
+ tsk->fpu_counter = 0;
+ clear_fpu(tsk);
+ clear_used_math();
+}
+
+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;
+}
+
+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(prev_p, TIF_BLOCKSTEP) ^
+ test_tsk_thread_flag(next_p, TIF_BLOCKSTEP)) {
+ unsigned long debugctl = get_debugctlmsr();
+
+ debugctl &= ~DEBUGCTLMSR_BTF;
+ if (test_tsk_thread_flag(next_p, TIF_BLOCKSTEP))
+ debugctl |= DEBUGCTLMSR_BTF;
+
+ update_debugctlmsr(debugctl);
+ }
+
+ 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);
+ }
+ propagate_user_return_notify(prev_p, next_p);
+}
+
+int sys_fork(struct pt_regs *regs)
+{
+ return do_fork(SIGCHLD, regs->sp, regs, 0, NULL, NULL);
+}
+
+/*
+ * 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.
+ */
+int sys_vfork(struct pt_regs *regs)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->sp, regs, 0,
+ NULL, NULL);
+}
+
+long
+sys_clone(unsigned long clone_flags, unsigned long newsp,
+ void __user *parent_tid, void __user *child_tid, struct pt_regs *regs)
+{
+ if (!newsp)
+ newsp = regs->sp;
+ return do_fork(clone_flags, newsp, regs, 0, parent_tid, child_tid);
+}
+
+/*
+ * This gets run with %si containing the
+ * function to call, and %di containing
+ * the "args".
+ */
+extern void kernel_thread_helper(void);
+
+/*
+ * Create a kernel thread
+ */
+int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
+{
+ struct pt_regs regs;
+
+ memset(&regs, 0, sizeof(regs));
+
+ regs.si = (unsigned long) fn;
+ regs.di = (unsigned long) arg;
+
+#ifdef CONFIG_X86_32
+ regs.ds = __USER_DS;
+ regs.es = __USER_DS;
+ regs.fs = __KERNEL_PERCPU;
+ regs.gs = __KERNEL_STACK_CANARY;
+#else
+ regs.ss = __KERNEL_DS;
+#endif
+
+ regs.orig_ax = -1;
+ regs.ip = (unsigned long) kernel_thread_helper;
+ regs.cs = __KERNEL_CS | get_kernel_rpl();
+ regs.flags = X86_EFLAGS_IF | X86_EFLAGS_BIT1;
+
+ /* Ok, create the new process.. */
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+/*
+ * sys_execve() executes a new program.
+ */
+long sys_execve(const char __user *name,
+ const char __user *const __user *argv,
+ const char __user *const __user *envp, struct pt_regs *regs)
+{
+ long error;
+ char *filename;
+
+ filename = getname(name);
+ error = PTR_ERR(filename);
+ if (IS_ERR(filename))
+ return error;
+ error = do_execve(filename, argv, envp, regs);
+
+#ifdef CONFIG_X86_32
+ if (error == 0) {
+ /* Make sure we don't return using sysenter.. */
+ set_thread_flag(TIF_IRET);
+ }
+#endif
+
+ putname(filename);
+ return error;
+}
+
+/*
+ * Idle related variables and functions
+ */
+unsigned long boot_option_idle_override = IDLE_NO_OVERRIDE;
+EXPORT_SYMBOL(boot_option_idle_override);
+
+/*
+ * Powermanagement idle function, if any..
+ */
+void (*pm_idle)(void);
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(pm_idle);
+#endif
+
+static inline int hlt_use_halt(void)
+{
+ return 1;
+}
+
+#ifndef CONFIG_SMP
+static inline void play_dead(void)
+{
+ BUG();
+}
+#endif
+
+#ifdef CONFIG_X86_64
+void enter_idle(void)
+{
+ percpu_write(is_idle, 1);
+ idle_notifier_call_chain(IDLE_START);
+}
+
+static void __exit_idle(void)
+{
+ if (x86_test_and_clear_bit_percpu(0, is_idle) == 0)
+ return;
+ idle_notifier_call_chain(IDLE_END);
+}
+
+/* Called from interrupts to signify idle end */
+void exit_idle(void)
+{
+ /* idle loop has pid 0 */
+ if (current->pid)
+ return;
+ __exit_idle();
+}
+#endif
+
+/*
+ * The idle thread. There's no useful work to be
+ * done, so just try to conserve power and have a
+ * low exit latency (ie sit in a loop waiting for
+ * somebody to say that they'd like to reschedule)
+ */
+void cpu_idle(void)
+{
+ /*
+ * 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();
+ current_thread_info()->status |= TS_POLLING;
+
+ while (1) {
+ tick_nohz_idle_enter();
+
+ while (!need_resched()) {
+ rmb();
+
+ if (cpu_is_offline(smp_processor_id()))
+ play_dead();
+
+ /*
+ * Idle routines should keep interrupts disabled
+ * from here on, until they go to idle.
+ * Otherwise, idle callbacks can misfire.
+ */
+ local_touch_nmi();
+ local_irq_disable();
+
+ enter_idle();
+
+ /* Don't trace irqs off for idle */
+ stop_critical_timings();
+
+ /* enter_idle() needs rcu for notifiers */
+ rcu_idle_enter();
+
+ if (cpuidle_idle_call())
+ pm_idle();
+
+ rcu_idle_exit();
+ start_critical_timings();
+
+ /* In many cases the interrupt that ended idle
+ has already called exit_idle. But some idle
+ loops can be woken up without interrupt. */
+ __exit_idle();
+ }
+
+ tick_nohz_idle_exit();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+/*
+ * We use this if we don't have any better
+ * idle routine..
+ */
+void default_idle(void)
+{
+ if (hlt_use_halt()) {
+ trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
+ trace_cpu_idle_rcuidle(1, smp_processor_id());
+ current_thread_info()->status &= ~TS_POLLING;
+ /*
+ * TS_POLLING-cleared state must be visible before we
+ * test NEED_RESCHED:
+ */
+ smp_mb();
+
+ if (!need_resched())
+ safe_halt(); /* enables interrupts racelessly */
+ else
+ local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
+ trace_power_end_rcuidle(smp_processor_id());
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+ } else {
+ local_irq_enable();
+ /* loop is done by the caller */
+ cpu_relax();
+ }
+}
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(default_idle);
+#endif
+
+bool set_pm_idle_to_default(void)
+{
+ bool ret = !!pm_idle;
+
+ pm_idle = default_idle;
+
+ return ret;
+}
+void stop_this_cpu(void *dummy)
+{
+ local_irq_disable();
+ /*
+ * Remove this CPU:
+ */
+ set_cpu_online(smp_processor_id(), false);
+ disable_local_APIC();
+
+ for (;;) {
+ if (hlt_works(smp_processor_id()))
+ halt();
+ }
+}
+
+static void do_nothing(void *unused)
+{
+}
+
+/*
+ * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
+ * pm_idle and update to new pm_idle value. Required while changing pm_idle
+ * handler on SMP systems.
+ *
+ * Caller must have changed pm_idle to the new value before the call. Old
+ * pm_idle value will not be used by any CPU after the return of this function.
+ */
+void cpu_idle_wait(void)
+{
+ smp_mb();
+ /* kick all the CPUs so that they exit out of pm_idle */
+ smp_call_function(do_nothing, NULL, 1);
+}
+EXPORT_SYMBOL_GPL(cpu_idle_wait);
+
+/* Default MONITOR/MWAIT with no hints, used for default C1 state */
+static void mwait_idle(void)
+{
+ if (!need_resched()) {
+ trace_power_start_rcuidle(POWER_CSTATE, 1, smp_processor_id());
+ trace_cpu_idle_rcuidle(1, smp_processor_id());
+ if (this_cpu_has(X86_FEATURE_CLFLUSH_MONITOR))
+ clflush((void *)&current_thread_info()->flags);
+
+ __monitor((void *)&current_thread_info()->flags, 0, 0);
+ smp_mb();
+ if (!need_resched())
+ __sti_mwait(0, 0);
+ else
+ local_irq_enable();
+ trace_power_end_rcuidle(smp_processor_id());
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+ } else
+ local_irq_enable();
+}
+
+/*
+ * On SMP it's slightly faster (but much more power-consuming!)
+ * to poll the ->work.need_resched flag instead of waiting for the
+ * cross-CPU IPI to arrive. Use this option with caution.
+ */
+static void poll_idle(void)
+{
+ trace_power_start_rcuidle(POWER_CSTATE, 0, smp_processor_id());
+ trace_cpu_idle_rcuidle(0, smp_processor_id());
+ local_irq_enable();
+ while (!need_resched())
+ cpu_relax();
+ trace_power_end_rcuidle(smp_processor_id());
+ trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
+}
+
+/*
+ * mwait selection logic:
+ *
+ * It depends on the CPU. For AMD CPUs that support MWAIT this is
+ * wrong. Family 0x10 and 0x11 CPUs will enter C1 on HLT. Powersavings
+ * then depend on a clock divisor and current Pstate of the core. If
+ * all cores of a processor are in halt state (C1) the processor can
+ * enter the C1E (C1 enhanced) state. If mwait is used this will never
+ * happen.
+ *
+ * idle=mwait overrides this decision and forces the usage of mwait.
+ */
+
+#define MWAIT_INFO 0x05
+#define MWAIT_ECX_EXTENDED_INFO 0x01
+#define MWAIT_EDX_C1 0xf0
+
+int mwait_usable(const struct cpuinfo_x86 *c)
+{
+ u32 eax, ebx, ecx, edx;
+
+ if (boot_option_idle_override == IDLE_FORCE_MWAIT)
+ return 1;
+
+ if (c->cpuid_level < MWAIT_INFO)
+ return 0;
+
+ cpuid(MWAIT_INFO, &eax, &ebx, &ecx, &edx);
+ /* Check, whether EDX has extended info about MWAIT */
+ if (!(ecx & MWAIT_ECX_EXTENDED_INFO))
+ return 1;
+
+ /*
+ * edx enumeratios MONITOR/MWAIT extensions. Check, whether
+ * C1 supports MWAIT
+ */
+ return (edx & MWAIT_EDX_C1);
+}
+
+bool amd_e400_c1e_detected;
+EXPORT_SYMBOL(amd_e400_c1e_detected);
+
+static cpumask_var_t amd_e400_c1e_mask;
+
+void amd_e400_remove_cpu(int cpu)
+{
+ if (amd_e400_c1e_mask != NULL)
+ cpumask_clear_cpu(cpu, amd_e400_c1e_mask);
+}
+
+/*
+ * AMD Erratum 400 aware idle routine. We check for C1E active in the interrupt
+ * pending message MSR. If we detect C1E, then we handle it the same
+ * way as C3 power states (local apic timer and TSC stop)
+ */
+static void amd_e400_idle(void)
+{
+ if (need_resched())
+ return;
+
+ if (!amd_e400_c1e_detected) {
+ u32 lo, hi;
+
+ rdmsr(MSR_K8_INT_PENDING_MSG, lo, hi);
+
+ if (lo & K8_INTP_C1E_ACTIVE_MASK) {
+ amd_e400_c1e_detected = true;
+ if (!boot_cpu_has(X86_FEATURE_NONSTOP_TSC))
+ mark_tsc_unstable("TSC halt in AMD C1E");
+ printk(KERN_INFO "System has AMD C1E enabled\n");
+ }
+ }
+
+ if (amd_e400_c1e_detected) {
+ int cpu = smp_processor_id();
+
+ if (!cpumask_test_cpu(cpu, amd_e400_c1e_mask)) {
+ cpumask_set_cpu(cpu, amd_e400_c1e_mask);
+ /*
+ * Force broadcast so ACPI can not interfere.
+ */
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_FORCE,
+ &cpu);
+ printk(KERN_INFO "Switch to broadcast mode on CPU%d\n",
+ cpu);
+ }
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &cpu);
+
+ default_idle();
+
+ /*
+ * The switch back from broadcast mode needs to be
+ * called with interrupts disabled.
+ */
+ local_irq_disable();
+ clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &cpu);
+ local_irq_enable();
+ } else
+ default_idle();
+}
+
+void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
+{
+#ifdef CONFIG_SMP
+ if (pm_idle == poll_idle && smp_num_siblings > 1) {
+ printk_once(KERN_WARNING "WARNING: polling idle and HT enabled,"
+ " performance may degrade.\n");
+ }
+#endif
+ if (pm_idle)
+ return;
+
+ if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
+ /*
+ * One CPU supports mwait => All CPUs supports mwait
+ */
+ printk(KERN_INFO "using mwait in idle threads.\n");
+ pm_idle = mwait_idle;
+ } else if (cpu_has_amd_erratum(amd_erratum_400)) {
+ /* E400: APIC timer interrupt does not wake up CPU from C1e */
+ printk(KERN_INFO "using AMD E400 aware idle routine\n");
+ pm_idle = amd_e400_idle;
+ } else
+ pm_idle = default_idle;
+}
+
+void __init init_amd_e400_c1e_mask(void)
+{
+ /* If we're using amd_e400_idle, we need to allocate amd_e400_c1e_mask. */
+ if (pm_idle == amd_e400_idle)
+ zalloc_cpumask_var(&amd_e400_c1e_mask, GFP_KERNEL);
+}
+
+static int __init idle_setup(char *str)
+{
+ if (!str)
+ return -EINVAL;
+
+ if (!strcmp(str, "poll")) {
+ printk("using polling idle threads.\n");
+ pm_idle = poll_idle;
+ boot_option_idle_override = IDLE_POLL;
+ } else if (!strcmp(str, "mwait")) {
+ boot_option_idle_override = IDLE_FORCE_MWAIT;
+ WARN_ONCE(1, "\"idle=mwait\" will be removed in 2012\n");
+ } else if (!strcmp(str, "halt")) {
+ /*
+ * When the boot option of idle=halt is added, halt is
+ * forced to be used for CPU idle. In such case CPU C2/C3
+ * won't be used again.
+ * To continue to load the CPU idle driver, don't touch
+ * the boot_option_idle_override.
+ */
+ pm_idle = default_idle;
+ boot_option_idle_override = IDLE_HALT;
+ } else if (!strcmp(str, "nomwait")) {
+ /*
+ * If the boot option of "idle=nomwait" is added,
+ * it means that mwait will be disabled for CPU C2/C3
+ * states. In such case it won't touch the variable
+ * of boot_option_idle_override.
+ */
+ boot_option_idle_override = IDLE_NOMWAIT;
+ } else
+ return -1;
+
+ return 0;
+}
+early_param("idle", idle_setup);
+
+unsigned long arch_align_stack(unsigned long sp)
+{
+ if (!(current->personality & ADDR_NO_RANDOMIZE) && randomize_va_space)
+ sp -= get_random_int() % 8192;
+ return sp & ~0xf;
+}
+
+unsigned long arch_randomize_brk(struct mm_struct *mm)
+{
+ unsigned long range_end = mm->brk + 0x02000000;
+ return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+}
+