* This file handles the architecture-dependent parts of process handling..
*/
-#include <stdarg.h>
-
+#include <linux/stackprotector.h>
#include <linux/cpu.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/ptrace.h>
-#include <linux/random.h>
#include <linux/notifier.h>
#include <linux/kprobes.h>
#include <linux/kdebug.h>
#include <linux/tick.h>
#include <linux/prctl.h>
+#include <linux/uaccess.h>
+#include <linux/io.h>
+#include <linux/ftrace.h>
+#include <linux/dmi.h>
-#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
-#include <asm/io.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);
-unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED;
-
-unsigned long boot_option_idle_override = 0;
-EXPORT_SYMBOL(boot_option_idle_override);
+DEFINE_PER_CPU(unsigned long, old_rsp);
+static DEFINE_PER_CPU(unsigned char, is_idle);
-/*
- * Powermanagement idle function, if any..
- */
-void (*pm_idle)(void);
-EXPORT_SYMBOL(pm_idle);
+unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED;
static ATOMIC_NOTIFIER_HEAD(idle_notifier);
{
atomic_notifier_chain_register(&idle_notifier, n);
}
+EXPORT_SYMBOL_GPL(idle_notifier_register);
+
+void idle_notifier_unregister(struct notifier_block *n)
+{
+ atomic_notifier_chain_unregister(&idle_notifier, n);
+}
+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);
}
__exit_idle();
}
-/*
- * We use this if we don't have any better
- * idle routine..
- */
-void default_idle(void)
-{
- current_thread_info()->status &= ~TS_POLLING;
- /*
- * TS_POLLING-cleared state must be visible before we
- * test NEED_RESCHED:
- */
- smp_mb();
- local_irq_disable();
- if (!need_resched()) {
- safe_halt(); /* enables interrupts racelessly */
- local_irq_disable();
- }
- local_irq_enable();
- current_thread_info()->status |= TS_POLLING;
-}
-
-/*
- * On SMP it's slightly faster (but much more power-consuming!)
- * to poll the ->need_resched flag instead of waiting for the
- * cross-CPU IPI to arrive. Use this option with caution.
- */
-static void poll_idle(void)
-{
- local_irq_enable();
- cpu_relax();
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-DECLARE_PER_CPU(int, cpu_state);
-
-#include <asm/nmi.h>
-/* We halt the CPU with physical CPU hotplug */
-static inline void play_dead(void)
-{
- idle_task_exit();
- wbinvd();
- mb();
- /* Ack it */
- __get_cpu_var(cpu_state) = CPU_DEAD;
-
- local_irq_disable();
- while (1)
- halt();
-}
-#else
+#ifndef CONFIG_SMP
static inline void play_dead(void)
{
BUG();
}
-#endif /* CONFIG_HOTPLUG_CPU */
+#endif
/*
* The idle thread. There's no useful work to be
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();
+ tick_nohz_stop_sched_tick(1);
while (!need_resched()) {
- void (*idle)(void);
rmb();
- idle = pm_idle;
- if (!idle)
- idle = default_idle;
+
if (cpu_is_offline(smp_processor_id()))
play_dead();
/*
*/
local_irq_disable();
enter_idle();
- idle();
+ /* Don't trace irqs off for idle */
+ stop_critical_timings();
+ pm_idle();
+ 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. */
}
}
-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, 0, 1);
-}
-EXPORT_SYMBOL_GPL(cpu_idle_wait);
-
-/*
- * This uses new MONITOR/MWAIT instructions on P4 processors with PNI,
- * which can obviate IPI to trigger checking of need_resched.
- * We execute MONITOR against need_resched and enter optimized wait state
- * through MWAIT. Whenever someone changes need_resched, we would be woken
- * up from MWAIT (without an IPI).
- *
- * New with Core Duo processors, MWAIT can take some hints based on CPU
- * capability.
- */
-void mwait_idle_with_hints(unsigned long ax, unsigned long cx)
-{
- if (!need_resched()) {
- __monitor((void *)¤t_thread_info()->flags, 0, 0);
- smp_mb();
- if (!need_resched())
- __mwait(ax, cx);
- }
-}
-
-/* Default MONITOR/MWAIT with no hints, used for default C1 state */
-static void mwait_idle(void)
-{
- if (!need_resched()) {
- __monitor((void *)¤t_thread_info()->flags, 0, 0);
- smp_mb();
- if (!need_resched())
- __sti_mwait(0, 0);
- else
- local_irq_enable();
- } else {
- local_irq_enable();
- }
-}
-
-
-static int __cpuinit mwait_usable(const struct cpuinfo_x86 *c)
-{
- if (force_mwait)
- return 1;
- /* Any C1 states supported? */
- return c->cpuid_level >= 5 && ((cpuid_edx(5) >> 4) & 0xf) > 0;
-}
-
-void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c)
-{
- static int selected;
-
- if (selected)
- return;
-#ifdef CONFIG_X86_SMP
- if (pm_idle == poll_idle && smp_num_siblings > 1) {
- printk(KERN_WARNING "WARNING: polling idle and HT enabled,"
- " performance may degrade.\n");
- }
-#endif
- if (cpu_has(c, X86_FEATURE_MWAIT) && mwait_usable(c)) {
- /*
- * Skip, if setup has overridden idle.
- * One CPU supports mwait => All CPUs supports mwait
- */
- if (!pm_idle) {
- printk(KERN_INFO "using mwait in idle threads.\n");
- pm_idle = mwait_idle;
- }
- }
- selected = 1;
-}
-
-static int __init idle_setup(char *str)
-{
- if (!strcmp(str, "poll")) {
- printk("using polling idle threads.\n");
- pm_idle = poll_idle;
- } else if (!strcmp(str, "mwait"))
- force_mwait = 1;
- else
- return -1;
-
- boot_option_idle_override = 1;
- return 0;
-}
-early_param("idle", idle_setup);
-
/* Prints also some state that isn't saved in the pt_regs */
-void __show_regs(struct pt_regs * regs)
+void __show_regs(struct pt_regs *regs, int all)
{
unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L, fs, gs, shadowgs;
unsigned long d0, d1, d2, d3, d6, d7;
unsigned int fsindex, gsindex;
unsigned int ds, cs, es;
+ const char *board;
printk("\n");
print_modules();
- printk("Pid: %d, comm: %.20s %s %s %.*s\n",
+ board = dmi_get_system_info(DMI_PRODUCT_NAME);
+ if (!board)
+ board = "";
+ printk(KERN_INFO "Pid: %d, comm: %.20s %s %s %.*s %s\n",
current->pid, current->comm, print_tainted(),
init_utsname()->release,
(int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
- printk("RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
+ init_utsname()->version, board);
+ printk(KERN_INFO "RIP: %04lx:[<%016lx>] ", regs->cs & 0xffff, regs->ip);
printk_address(regs->ip, 1);
- printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->sp,
- regs->flags);
- printk("RAX: %016lx RBX: %016lx RCX: %016lx\n",
+ printk(KERN_INFO "RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss,
+ regs->sp, regs->flags);
+ printk(KERN_INFO "RAX: %016lx RBX: %016lx RCX: %016lx\n",
regs->ax, regs->bx, regs->cx);
- printk("RDX: %016lx RSI: %016lx RDI: %016lx\n",
+ printk(KERN_INFO "RDX: %016lx RSI: %016lx RDI: %016lx\n",
regs->dx, regs->si, regs->di);
- printk("RBP: %016lx R08: %016lx R09: %016lx\n",
+ printk(KERN_INFO "RBP: %016lx R08: %016lx R09: %016lx\n",
regs->bp, regs->r8, regs->r9);
- printk("R10: %016lx R11: %016lx R12: %016lx\n",
- regs->r10, regs->r11, regs->r12);
- printk("R13: %016lx R14: %016lx R15: %016lx\n",
- regs->r13, regs->r14, regs->r15);
-
- asm("movl %%ds,%0" : "=r" (ds));
- asm("movl %%cs,%0" : "=r" (cs));
- asm("movl %%es,%0" : "=r" (es));
+ printk(KERN_INFO "R10: %016lx R11: %016lx R12: %016lx\n",
+ regs->r10, regs->r11, regs->r12);
+ printk(KERN_INFO "R13: %016lx R14: %016lx R15: %016lx\n",
+ regs->r13, regs->r14, regs->r15);
+
+ asm("movl %%ds,%0" : "=r" (ds));
+ asm("movl %%cs,%0" : "=r" (cs));
+ asm("movl %%es,%0" : "=r" (es));
asm("movl %%fs,%0" : "=r" (fsindex));
asm("movl %%gs,%0" : "=r" (gsindex));
rdmsrl(MSR_FS_BASE, fs);
- rdmsrl(MSR_GS_BASE, gs);
- rdmsrl(MSR_KERNEL_GS_BASE, shadowgs);
+ rdmsrl(MSR_GS_BASE, gs);
+ rdmsrl(MSR_KERNEL_GS_BASE, shadowgs);
+
+ if (!all)
+ return;
cr0 = read_cr0();
cr2 = read_cr2();
cr3 = read_cr3();
cr4 = read_cr4();
- printk("FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
- fs,fsindex,gs,gsindex,shadowgs);
- printk("CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds, es, cr0);
- printk("CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3, cr4);
+ printk(KERN_INFO "FS: %016lx(%04x) GS:%016lx(%04x) knlGS:%016lx\n",
+ fs, fsindex, gs, gsindex, shadowgs);
+ printk(KERN_INFO "CS: %04x DS: %04x ES: %04x CR0: %016lx\n", cs, ds,
+ es, cr0);
+ printk(KERN_INFO "CR2: %016lx CR3: %016lx CR4: %016lx\n", cr2, cr3,
+ cr4);
get_debugreg(d0, 0);
get_debugreg(d1, 1);
get_debugreg(d2, 2);
- printk("DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
+ printk(KERN_INFO "DR0: %016lx DR1: %016lx DR2: %016lx\n", d0, d1, d2);
get_debugreg(d3, 3);
get_debugreg(d6, 6);
get_debugreg(d7, 7);
- printk("DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
+ printk(KERN_INFO "DR3: %016lx DR6: %016lx DR7: %016lx\n", d3, d6, d7);
}
void show_regs(struct pt_regs *regs)
{
- printk("CPU %d:", smp_processor_id());
- __show_regs(regs);
+ printk(KERN_INFO "CPU %d:", smp_processor_id());
+ __show_regs(regs, 1);
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();
- }
-}
-
-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..
- */
- clear_fpu(tsk);
- clear_used_math();
-}
-
void release_thread(struct task_struct *dead_task)
{
if (dead_task->mm) {
unlazy_fpu(tsk);
}
-int copy_thread(int nr, unsigned long clone_flags, unsigned long sp,
+int copy_thread(unsigned long clone_flags, unsigned long sp,
unsigned long unused,
- struct task_struct * p, struct pt_regs * regs)
+ struct task_struct *p, struct pt_regs *regs)
{
int err;
- struct pt_regs * childregs;
+ struct pt_regs *childregs;
struct task_struct *me = current;
childregs = ((struct pt_regs *)
p->thread.fs = me->thread.fs;
p->thread.gs = me->thread.gs;
- asm("mov %%gs,%0" : "=m" (p->thread.gsindex));
- asm("mov %%fs,%0" : "=m" (p->thread.fsindex));
- asm("mov %%es,%0" : "=m" (p->thread.es));
- asm("mov %%ds,%0" : "=m" (p->thread.ds));
+ savesegment(gs, p->thread.gsindex);
+ savesegment(fs, p->thread.fsindex);
+ savesegment(es, p->thread.es);
+ savesegment(ds, p->thread.ds);
if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) {
p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL);
if (test_thread_flag(TIF_IA32))
err = do_set_thread_area(p, -1,
(struct user_desc __user *)childregs->si, 0);
- else
-#endif
- err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);
- if (err)
+ else
+#endif
+ err = do_arch_prctl(p, ARCH_SET_FS, childregs->r8);
+ if (err)
goto out;
}
+
+ clear_tsk_thread_flag(p, TIF_DS_AREA_MSR);
+ p->thread.ds_ctx = NULL;
+
+ clear_tsk_thread_flag(p, TIF_DEBUGCTLMSR);
+ p->thread.debugctlmsr = 0;
+
err = 0;
out:
if (err && p->thread.io_bitmap_ptr) {
void
start_thread(struct pt_regs *regs, unsigned long new_ip, unsigned long new_sp)
{
- asm volatile("movl %0, %%fs; movl %0, %%es; movl %0, %%ds" :: "r"(0));
+ loadsegment(fs, 0);
+ loadsegment(es, 0);
+ loadsegment(ds, 0);
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;
}
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);
-}
-
-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;
- unsigned long debugctl;
-
- prev = &prev_p->thread,
- next = &next_p->thread;
-
- debugctl = prev->debugctlmsr;
- if (next->ds_area_msr != prev->ds_area_msr) {
- /* 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, next->ds_area_msr);
- }
-
- if (next->debugctlmsr != debugctl)
- 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);
- }
-
-#ifdef X86_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
-}
-
/*
* switch_to(x,y) should switch tasks from x to y.
*
* - 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,
- *next = &next_p->thread;
+ struct thread_struct *prev = &prev_p->thread;
+ struct thread_struct *next = &next_p->thread;
int cpu = smp_processor_id();
struct tss_struct *tss = &per_cpu(init_tss, cpu);
+ unsigned fsindex, gsindex;
+ bool preload_fpu;
+
+ /*
+ * If the task has used fpu the last 5 timeslices, just do a full
+ * restore of the math state immediately to avoid the trap; the
+ * chances of needing FPU soon are obviously high now
+ */
+ preload_fpu = tsk_used_math(next_p) && next_p->fpu_counter > 5;
/* we're going to use this soon, after a few expensive things */
- if (next_p->fpu_counter>5)
+ if (preload_fpu)
prefetch(next->xstate);
/*
*/
load_sp0(tss, next);
- /*
+ /*
* Switch DS and ES.
* This won't pick up thread selector changes, but I guess that is ok.
*/
- asm volatile("mov %%es,%0" : "=m" (prev->es));
+ savesegment(es, prev->es);
if (unlikely(next->es | prev->es))
- loadsegment(es, next->es);
-
- asm volatile ("mov %%ds,%0" : "=m" (prev->ds));
+ loadsegment(es, next->es);
+
+ savesegment(ds, prev->ds);
if (unlikely(next->ds | prev->ds))
loadsegment(ds, next->ds);
- load_TLS(next, cpu);
- /*
- * Switch FS and GS.
+ /* We must save %fs and %gs before load_TLS() because
+ * %fs and %gs may be cleared by load_TLS().
+ *
+ * (e.g. xen_load_tls())
*/
- {
- unsigned fsindex;
- asm volatile("movl %%fs,%0" : "=r" (fsindex));
- /* segment register != 0 always requires a reload.
- also reload when it has changed.
- when prev process used 64bit base always reload
- to avoid an information leak. */
- if (unlikely(fsindex | next->fsindex | prev->fs)) {
- loadsegment(fs, next->fsindex);
- /* check if the user used a selector != 0
- * if yes clear 64bit base, since overloaded base
- * is always mapped to the Null selector
- */
- if (fsindex)
- prev->fs = 0;
- }
- /* when next process has a 64bit base use it */
- if (next->fs)
- wrmsrl(MSR_FS_BASE, next->fs);
- prev->fsindex = fsindex;
- }
- {
- unsigned gsindex;
- asm volatile("movl %%gs,%0" : "=r" (gsindex));
- if (unlikely(gsindex | next->gsindex | prev->gs)) {
- load_gs_index(next->gsindex);
- if (gsindex)
- prev->gs = 0;
- }
- if (next->gs)
- wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
- prev->gsindex = gsindex;
- }
+ savesegment(fs, fsindex);
+ savesegment(gs, gsindex);
+
+ load_TLS(next, cpu);
/* Must be after DS reload */
unlazy_fpu(prev_p);
- /*
- * Switch the PDA and FPU contexts.
+ /* Make sure cpu is ready for new context */
+ if (preload_fpu)
+ clts();
+
+ /*
+ * Leave lazy mode, flushing any hypercalls made here.
+ * This must be done before restoring TLS segments so
+ * the GDT and LDT are properly updated, and must be
+ * done before math_state_restore, so the TS bit is up
+ * to date.
*/
- prev->usersp = read_pda(oldrsp);
- write_pda(oldrsp, next->usersp);
- write_pda(pcurrent, next_p);
-
- write_pda(kernelstack,
- (unsigned long)task_stack_page(next_p) + THREAD_SIZE - PDA_STACKOFFSET);
-#ifdef CONFIG_CC_STACKPROTECTOR
- write_pda(stack_canary, next_p->stack_canary);
+ arch_end_context_switch(next_p);
+
/*
- * Build time only check to make sure the stack_canary is at
- * offset 40 in the pda; this is a gcc ABI requirement
+ * Switch FS and GS.
+ *
+ * Segment register != 0 always requires a reload. Also
+ * reload when it has changed. When prev process used 64bit
+ * base always reload to avoid an information leak.
*/
- BUILD_BUG_ON(offsetof(struct x8664_pda, stack_canary) != 40);
-#endif
+ if (unlikely(fsindex | next->fsindex | prev->fs)) {
+ loadsegment(fs, next->fsindex);
+ /*
+ * Check if the user used a selector != 0; if yes
+ * clear 64bit base, since overloaded base is always
+ * mapped to the Null selector
+ */
+ if (fsindex)
+ prev->fs = 0;
+ }
+ /* when next process has a 64bit base use it */
+ if (next->fs)
+ wrmsrl(MSR_FS_BASE, next->fs);
+ prev->fsindex = fsindex;
+
+ if (unlikely(gsindex | next->gsindex | prev->gs)) {
+ load_gs_index(next->gsindex);
+ if (gsindex)
+ prev->gs = 0;
+ }
+ if (next->gs)
+ wrmsrl(MSR_KERNEL_GS_BASE, next->gs);
+ prev->gsindex = gsindex;
+
+ /*
+ * Switch the PDA and FPU contexts.
+ */
+ prev->usersp = percpu_read(old_rsp);
+ percpu_write(old_rsp, next->usersp);
+ percpu_write(current_task, next_p);
+
+ percpu_write(kernel_stack,
+ (unsigned long)task_stack_page(next_p) +
+ THREAD_SIZE - KERNEL_STACK_OFFSET);
/*
* Now maybe reload the debug registers and handle I/O bitmaps
task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV))
__switch_to_xtra(prev_p, next_p, tss);
- /* If the task has used fpu the last 5 timeslices, just do a full
- * restore of the math state immediately to avoid the trap; the
- * chances of needing FPU soon are obviously high now
+ /*
+ * Preload the FPU context, now that we've determined that the
+ * task is likely to be using it.
*/
- if (next_p->fpu_counter>5)
- math_state_restore();
+ if (preload_fpu)
+ __math_state_restore();
return prev_p;
}
char __user * __user *envp, struct pt_regs *regs)
{
long error;
- char * filename;
+ char *filename;
filename = getname(name);
error = PTR_ERR(filename);
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)
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;
- u64 fp,ip;
+ u64 fp, ip;
int count = 0;
- if (!p || p == current || p->state==TASK_RUNNING)
- return 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
stack = (unsigned long)task_stack_page(p);
- if (p->thread.sp < stack || p->thread.sp > stack+THREAD_SIZE)
+ if (p->thread.sp < stack || p->thread.sp >= stack+THREAD_SIZE)
return 0;
fp = *(u64 *)(p->thread.sp);
- do {
+ do {
if (fp < (unsigned long)stack ||
- fp > (unsigned long)stack+THREAD_SIZE)
- return 0;
+ fp >= (unsigned long)stack+THREAD_SIZE)
+ return 0;
ip = *(u64 *)(fp+8);
if (!in_sched_functions(ip))
return ip;
- fp = *(u64 *)fp;
- } while (count++ < 16);
+ fp = *(u64 *)fp;
+ } while (count++ < 16);
return 0;
}
long do_arch_prctl(struct task_struct *task, int code, unsigned long addr)
-{
- int ret = 0;
+{
+ int ret = 0;
int doit = task == current;
int cpu;
- switch (code) {
+ switch (code) {
case ARCH_SET_GS:
if (addr >= TASK_SIZE_OF(task))
- return -EPERM;
+ return -EPERM;
cpu = get_cpu();
- /* handle small bases via the GDT because that's faster to
+ /* handle small bases via the GDT because that's faster to
switch. */
- if (addr <= 0xffffffff) {
- set_32bit_tls(task, GS_TLS, addr);
- if (doit) {
+ if (addr <= 0xffffffff) {
+ set_32bit_tls(task, GS_TLS, addr);
+ if (doit) {
load_TLS(&task->thread, cpu);
- load_gs_index(GS_TLS_SEL);
+ load_gs_index(GS_TLS_SEL);
}
- task->thread.gsindex = GS_TLS_SEL;
+ task->thread.gsindex = GS_TLS_SEL;
task->thread.gs = 0;
- } else {
+ } else {
task->thread.gsindex = 0;
task->thread.gs = addr;
if (doit) {
load_gs_index(0);
ret = checking_wrmsrl(MSR_KERNEL_GS_BASE, addr);
- }
+ }
}
put_cpu();
break;
set_32bit_tls(task, FS_TLS, addr);
if (doit) {
load_TLS(&task->thread, cpu);
- asm volatile("movl %0,%%fs" :: "r"(FS_TLS_SEL));
+ loadsegment(fs, FS_TLS_SEL);
}
task->thread.fsindex = FS_TLS_SEL;
task->thread.fs = 0;
if (doit) {
/* set the selector to 0 to not confuse
__switch_to */
- asm volatile("movl %0,%%fs" :: "r" (0));
+ loadsegment(fs, 0);
ret = checking_wrmsrl(MSR_FS_BASE, addr);
}
}
if (task->thread.gsindex == GS_TLS_SEL)
base = read_32bit_tls(task, GS_TLS);
else if (doit) {
- asm("movl %%gs,%0" : "=r" (gsindex));
+ savesegment(gs, gsindex);
if (gsindex)
rdmsrl(MSR_KERNEL_GS_BASE, base);
else
base = task->thread.gs;
- }
- else
+ } else
base = task->thread.gs;
ret = put_user(base, (unsigned long __user *)addr);
break;
return do_arch_prctl(current, code, addr);
}
-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 KSTK_ESP(struct task_struct *task)
{
- unsigned long range_end = mm->brk + 0x02000000;
- return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
+ return (test_tsk_thread_flag(task, TIF_IA32)) ?
+ (task_pt_regs(task)->sp) : ((task)->thread.usersp);
}