| /* |
| * Copyright (C) 1995 Linus Torvalds |
| * |
| * Pentium III FXSR, SSE support |
| * Gareth Hughes <gareth@valinux.com>, May 2000 |
| * |
| * X86-64 port |
| * Andi Kleen. |
| * |
| * CPU hotplug support - ashok.raj@intel.com |
| */ |
| |
| /* |
| * This file handles the architecture-dependent parts of process handling.. |
| */ |
| |
| #include <stdarg.h> |
| |
| #include <linux/cpu.h> |
| #include <linux/errno.h> |
| #include <linux/sched.h> |
| #include <linux/fs.h> |
| #include <linux/kernel.h> |
| #include <linux/mm.h> |
| #include <linux/elfcore.h> |
| #include <linux/smp.h> |
| #include <linux/slab.h> |
| #include <linux/user.h> |
| #include <linux/a.out.h> |
| #include <linux/interrupt.h> |
| #include <linux/utsname.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 <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> |
| |
| 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); |
| |
| /* |
| * Powermanagement idle function, if any.. |
| */ |
| void (*pm_idle)(void); |
| EXPORT_SYMBOL(pm_idle); |
| static DEFINE_PER_CPU(unsigned int, cpu_idle_state); |
| |
| static ATOMIC_NOTIFIER_HEAD(idle_notifier); |
| |
| void idle_notifier_register(struct notifier_block *n) |
| { |
| atomic_notifier_chain_register(&idle_notifier, n); |
| } |
| |
| void enter_idle(void) |
| { |
| write_pda(isidle, 1); |
| atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL); |
| } |
| |
| static void __exit_idle(void) |
| { |
| if (test_and_clear_bit_pda(0, isidle) == 0) |
| return; |
| atomic_notifier_call_chain(&idle_notifier, IDLE_END, NULL); |
| } |
| |
| /* Called from interrupts to signify idle end */ |
| void exit_idle(void) |
| { |
| /* idle loop has pid 0 */ |
| if (current->pid) |
| return; |
| __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()) { |
| ktime_t t0, t1; |
| u64 t0n, t1n; |
| |
| t0 = ktime_get(); |
| t0n = ktime_to_ns(t0); |
| safe_halt(); /* enables interrupts racelessly */ |
| local_irq_disable(); |
| t1 = ktime_get(); |
| t1n = ktime_to_ns(t1); |
| sched_clock_idle_wakeup_event(t1n - t0n); |
| } |
| 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 |
| static inline void play_dead(void) |
| { |
| BUG(); |
| } |
| #endif /* CONFIG_HOTPLUG_CPU */ |
| |
| /* |
| * 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) |
| { |
| current_thread_info()->status |= TS_POLLING; |
| /* endless idle loop with no priority at all */ |
| while (1) { |
| while (!need_resched()) { |
| void (*idle)(void); |
| |
| if (__get_cpu_var(cpu_idle_state)) |
| __get_cpu_var(cpu_idle_state) = 0; |
| |
| tick_nohz_stop_sched_tick(); |
| |
| rmb(); |
| idle = pm_idle; |
| if (!idle) |
| idle = default_idle; |
| 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_irq_disable(); |
| enter_idle(); |
| idle(); |
| /* 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_restart_sched_tick(); |
| preempt_enable_no_resched(); |
| schedule(); |
| preempt_disable(); |
| } |
| } |
| |
| static void do_nothing(void *unused) |
| { |
| } |
| |
| void cpu_idle_wait(void) |
| { |
| unsigned int cpu, this_cpu = get_cpu(); |
| cpumask_t map, tmp = current->cpus_allowed; |
| |
| set_cpus_allowed(current, cpumask_of_cpu(this_cpu)); |
| put_cpu(); |
| |
| cpus_clear(map); |
| for_each_online_cpu(cpu) { |
| per_cpu(cpu_idle_state, cpu) = 1; |
| cpu_set(cpu, map); |
| } |
| |
| __get_cpu_var(cpu_idle_state) = 0; |
| |
| wmb(); |
| do { |
| ssleep(1); |
| for_each_online_cpu(cpu) { |
| if (cpu_isset(cpu, map) && !per_cpu(cpu_idle_state, cpu)) |
| cpu_clear(cpu, map); |
| } |
| cpus_and(map, map, cpu_online_map); |
| /* |
| * We waited 1 sec, if a CPU still did not call idle |
| * it may be because it is in idle and not waking up |
| * because it has nothing to do. |
| * Give all the remaining CPUS a kick. |
| */ |
| smp_call_function_mask(map, do_nothing, 0, 0); |
| } while (!cpus_empty(map)); |
| |
| set_cpus_allowed(current, tmp); |
| } |
| 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(); |
| } |
| } |
| |
| void __cpuinit select_idle_routine(const struct cpuinfo_x86 *c) |
| { |
| static int printed; |
| if (cpu_has(c, X86_FEATURE_MWAIT)) { |
| /* |
| * Skip, if setup has overridden idle. |
| * One CPU supports mwait => All CPUs supports mwait |
| */ |
| if (!pm_idle) { |
| if (!printed) { |
| printk(KERN_INFO "using mwait in idle threads.\n"); |
| printed = 1; |
| } |
| pm_idle = mwait_idle; |
| } |
| } |
| } |
| |
| 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) |
| { |
| 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; |
| |
| printk("\n"); |
| print_modules(); |
| printk("Pid: %d, comm: %.20s %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); |
| printk_address(regs->ip); |
| printk("RSP: %04lx:%016lx EFLAGS: %08lx\n", regs->ss, regs->sp, |
| regs->flags); |
| printk("RAX: %016lx RBX: %016lx RCX: %016lx\n", |
| regs->ax, regs->bx, regs->cx); |
| printk("RDX: %016lx RSI: %016lx RDI: %016lx\n", |
| regs->dx, regs->si, regs->di); |
| printk("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)); |
| 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); |
| |
| 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); |
| |
| get_debugreg(d0, 0); |
| get_debugreg(d1, 1); |
| get_debugreg(d2, 2); |
| printk("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); |
| } |
| |
| void show_regs(struct pt_regs *regs) |
| { |
| printk("CPU %d:", smp_processor_id()); |
| __show_regs(regs); |
| show_trace(NULL, regs, (void *)(regs + 1)); |
| } |
| |
| /* |
| * 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) { |
| if (dead_task->mm->context.size) { |
| printk("WARNING: dead process %8s still has LDT? <%p/%d>\n", |
| dead_task->comm, |
| dead_task->mm->context.ldt, |
| dead_task->mm->context.size); |
| BUG(); |
| } |
| } |
| } |
| |
| static inline void set_32bit_tls(struct task_struct *t, int tls, u32 addr) |
| { |
| struct user_desc ud = { |
| .base_addr = addr, |
| .limit = 0xfffff, |
| .seg_32bit = 1, |
| .limit_in_pages = 1, |
| .useable = 1, |
| }; |
| struct desc_struct *desc = (void *)t->thread.tls_array; |
| desc += tls; |
| desc->a = LDT_entry_a(&ud); |
| desc->b = LDT_entry_b(&ud); |
| } |
| |
| static inline u32 read_32bit_tls(struct task_struct *t, int tls) |
| { |
| return get_desc_base(&t->thread.tls_array[tls]); |
| } |
| |
| /* |
| * This gets called before we allocate a new thread and copy |
| * the current task into it. |
| */ |
| void prepare_to_copy(struct task_struct *tsk) |
| { |
| unlazy_fpu(tsk); |
| } |
| |
| int copy_thread(int nr, unsigned long clone_flags, unsigned long sp, |
| unsigned long unused, |
| struct task_struct * p, struct pt_regs * regs) |
| { |
| int err; |
| struct pt_regs * childregs; |
| struct task_struct *me = current; |
| |
| childregs = ((struct pt_regs *) |
| (THREAD_SIZE + task_stack_page(p))) - 1; |
| *childregs = *regs; |
| |
| childregs->ax = 0; |
| childregs->sp = sp; |
| if (sp == ~0UL) |
| childregs->sp = (unsigned long)childregs; |
| |
| p->thread.sp = (unsigned long) childregs; |
| p->thread.sp0 = (unsigned long) (childregs+1); |
| p->thread.usersp = me->thread.usersp; |
| |
| set_tsk_thread_flag(p, TIF_FORK); |
| |
| 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)); |
| |
| if (unlikely(test_tsk_thread_flag(me, TIF_IO_BITMAP))) { |
| p->thread.io_bitmap_ptr = kmalloc(IO_BITMAP_BYTES, GFP_KERNEL); |
| if (!p->thread.io_bitmap_ptr) { |
| p->thread.io_bitmap_max = 0; |
| return -ENOMEM; |
| } |
| memcpy(p->thread.io_bitmap_ptr, me->thread.io_bitmap_ptr, |
| IO_BITMAP_BYTES); |
| set_tsk_thread_flag(p, TIF_IO_BITMAP); |
| } |
| |
| /* |
| * Set a new TLS for the child thread? |
| */ |
| if (clone_flags & CLONE_SETTLS) { |
| #ifdef CONFIG_IA32_EMULATION |
| 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) |
| goto out; |
| } |
| err = 0; |
| out: |
| if (err && p->thread.io_bitmap_ptr) { |
| kfree(p->thread.io_bitmap_ptr); |
| p->thread.io_bitmap_max = 0; |
| } |
| return err; |
| } |
| |
| /* |
| * This special macro can be used to load a debugging register |
| */ |
| #define loaddebug(thread, r) set_debugreg(thread->debugreg ## r, r) |
| |
| /* |
| * Capture the user space registers if the task is not running (in user space) |
| */ |
| int dump_task_regs(struct task_struct *tsk, elf_gregset_t *regs) |
| { |
| struct pt_regs *pp, ptregs; |
| |
| pp = task_pt_regs(tsk); |
| |
| ptregs = *pp; |
| ptregs.cs &= 0xffff; |
| ptregs.ss &= 0xffff; |
| |
| elf_core_copy_regs(regs, &ptregs); |
| |
| return 1; |
| } |
| |
| 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; |
| wrmsrl(MSR_IA32_DEBUGCTLMSR, 0); |
| wrmsrl(MSR_IA32_DS_AREA, next->ds_area_msr); |
| } |
| |
| if (next->debugctlmsr != debugctl) |
| wrmsrl(MSR_IA32_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(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); |
| } |
| |
| /* |
| * Last branch recording recofiguration of trace hardware and |
| * disentangling of trace data per task. |
| */ |
| 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); |
| } |
| |
| /* |
| * switch_to(x,y) should switch tasks from x to y. |
| * |
| * This could still be optimized: |
| * - fold all the options into a flag word and test it with a single test. |
| * - could test fs/gs bitsliced |
| * |
| * Kprobes not supported here. Set the probe on schedule instead. |
| */ |
| 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; |
| int cpu = smp_processor_id(); |
| struct tss_struct *tss = &per_cpu(init_tss, cpu); |
| |
| /* we're going to use this soon, after a few expensive things */ |
| if (next_p->fpu_counter>5) |
| prefetch(&next->i387.fxsave); |
| |
| /* |
| * Reload esp0, LDT and the page table pointer: |
| */ |
| tss->sp0 = next->sp0; |
| |
| /* |
| * 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)); |
| if (unlikely(next->es | prev->es)) |
| loadsegment(es, next->es); |
| |
| asm volatile ("mov %%ds,%0" : "=m" (prev->ds)); |
| if (unlikely(next->ds | prev->ds)) |
| loadsegment(ds, next->ds); |
| |
| load_TLS(next, cpu); |
| |
| /* |
| * Switch FS and GS. |
| */ |
| { |
| 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; |
| } |
| |
| /* Must be after DS reload */ |
| unlazy_fpu(prev_p); |
| |
| /* |
| * Switch the PDA and FPU contexts. |
| */ |
| 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); |
| /* |
| * 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 |
| |
| /* |
| * Now maybe reload the debug registers and handle I/O bitmaps |
| */ |
| if (unlikely(task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT || |
| 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 |
| */ |
| if (next_p->fpu_counter>5) |
| math_state_restore(); |
| return prev_p; |
| } |
| |
| /* |
| * sys_execve() executes a new program. |
| */ |
| asmlinkage |
| long sys_execve(char __user *name, char __user * __user *argv, |
| char __user * __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, ®s); |
| putname(filename); |
| return error; |
| } |
| |
| void set_personality_64bit(void) |
| { |
| /* inherit personality from parent */ |
| |
| /* Make sure to be in 64bit mode */ |
| clear_thread_flag(TIF_IA32); |
| |
| /* TBD: overwrites user setup. Should have two bits. |
| But 64bit processes have always behaved this way, |
| so it's not too bad. The main problem is just that |
| 32bit childs are affected again. */ |
| 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) |
| { |
| if (!newsp) |
| newsp = regs->sp; |
| 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; |
| int count = 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) |
| return 0; |
| fp = *(u64 *)(p->thread.sp); |
| do { |
| if (fp < (unsigned long)stack || |
| 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); |
| return 0; |
| } |
| |
| long do_arch_prctl(struct task_struct *task, int code, unsigned long addr) |
| { |
| int ret = 0; |
| int doit = task == current; |
| int cpu; |
| |
| switch (code) { |
| case ARCH_SET_GS: |
| if (addr >= TASK_SIZE_OF(task)) |
| return -EPERM; |
| cpu = get_cpu(); |
| /* handle small bases via the GDT because that's faster to |
| switch. */ |
| if (addr <= 0xffffffff) { |
| set_32bit_tls(task, GS_TLS, addr); |
| if (doit) { |
| load_TLS(&task->thread, cpu); |
| load_gs_index(GS_TLS_SEL); |
| } |
| task->thread.gsindex = GS_TLS_SEL; |
| task->thread.gs = 0; |
| } 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; |
| case ARCH_SET_FS: |
| /* Not strictly needed for fs, but do it for symmetry |
| with gs */ |
| if (addr >= TASK_SIZE_OF(task)) |
| return -EPERM; |
| cpu = get_cpu(); |
| /* handle small bases via the GDT because that's faster to |
| switch. */ |
| if (addr <= 0xffffffff) { |
| set_32bit_tls(task, FS_TLS, addr); |
| if (doit) { |
| load_TLS(&task->thread, cpu); |
| asm volatile("movl %0,%%fs" :: "r"(FS_TLS_SEL)); |
| } |
| task->thread.fsindex = FS_TLS_SEL; |
| task->thread.fs = 0; |
| } else { |
| task->thread.fsindex = 0; |
| task->thread.fs = addr; |
| if (doit) { |
| /* set the selector to 0 to not confuse |
| __switch_to */ |
| asm volatile("movl %0,%%fs" :: "r" (0)); |
| ret = checking_wrmsrl(MSR_FS_BASE, addr); |
| } |
| } |
| put_cpu(); |
| break; |
| case ARCH_GET_FS: { |
| unsigned long base; |
| if (task->thread.fsindex == FS_TLS_SEL) |
| base = read_32bit_tls(task, FS_TLS); |
| else if (doit) |
| rdmsrl(MSR_FS_BASE, base); |
| else |
| base = task->thread.fs; |
| ret = put_user(base, (unsigned long __user *)addr); |
| break; |
| } |
| case ARCH_GET_GS: { |
| unsigned long base; |
| unsigned gsindex; |
| if (task->thread.gsindex == GS_TLS_SEL) |
| base = read_32bit_tls(task, GS_TLS); |
| else if (doit) { |
| asm("movl %%gs,%0" : "=r" (gsindex)); |
| if (gsindex) |
| rdmsrl(MSR_KERNEL_GS_BASE, base); |
| else |
| base = task->thread.gs; |
| } |
| else |
| base = task->thread.gs; |
| ret = put_user(base, (unsigned long __user *)addr); |
| break; |
| } |
| |
| default: |
| ret = -EINVAL; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| long sys_arch_prctl(int code, unsigned long addr) |
| { |
| 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 range_end = mm->brk + 0x02000000; |
| return randomize_range(mm->brk, range_end, 0) ? : mm->brk; |
| } |
| |