extra-y := head.o init_task_32.o vmlinux.lds
-obj-y := process.o signal_32.o entry.o traps_32.o irq_32.o \
+obj-y := process_32.o signal_32.o entry.o traps_32.o irq_32.o \
ptrace_32.o time_32.o ioport_32.o ldt_32.o setup_32.o i8259_32.o sys_i386_32.o \
pci-dma_32.o i386_ksyms_32.o i387_32.o bootflag.o e820_32.o\
quirks.o i8237.o topology.o alternative.o i8253_32.o tsc.o
+++ /dev/null
-/*
- * linux/arch/i386/kernel/process.c
- *
- * Copyright (C) 1995 Linus Torvalds
- *
- * Pentium III FXSR, SSE support
- * Gareth Hughes <gareth@valinux.com>, May 2000
- */
-
-/*
- * 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/stddef.h>
-#include <linux/slab.h>
-#include <linux/vmalloc.h>
-#include <linux/user.h>
-#include <linux/a.out.h>
-#include <linux/interrupt.h>
-#include <linux/utsname.h>
-#include <linux/delay.h>
-#include <linux/reboot.h>
-#include <linux/init.h>
-#include <linux/mc146818rtc.h>
-#include <linux/module.h>
-#include <linux/kallsyms.h>
-#include <linux/ptrace.h>
-#include <linux/random.h>
-#include <linux/personality.h>
-#include <linux/tick.h>
-#include <linux/percpu.h>
-
-#include <asm/uaccess.h>
-#include <asm/pgtable.h>
-#include <asm/system.h>
-#include <asm/io.h>
-#include <asm/ldt.h>
-#include <asm/processor.h>
-#include <asm/i387.h>
-#include <asm/desc.h>
-#include <asm/vm86.h>
-#ifdef CONFIG_MATH_EMULATION
-#include <asm/math_emu.h>
-#endif
-
-#include <linux/err.h>
-
-#include <asm/tlbflush.h>
-#include <asm/cpu.h>
-
-asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
-
-static int hlt_counter;
-
-unsigned long boot_option_idle_override = 0;
-EXPORT_SYMBOL(boot_option_idle_override);
-
-DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
-EXPORT_PER_CPU_SYMBOL(current_task);
-
-DEFINE_PER_CPU(int, cpu_number);
-EXPORT_PER_CPU_SYMBOL(cpu_number);
-
-/*
- * Return saved PC of a blocked thread.
- */
-unsigned long thread_saved_pc(struct task_struct *tsk)
-{
- return ((unsigned long *)tsk->thread.esp)[3];
-}
-
-/*
- * Powermanagement idle function, if any..
- */
-void (*pm_idle)(void);
-EXPORT_SYMBOL(pm_idle);
-static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
-
-void disable_hlt(void)
-{
- hlt_counter++;
-}
-
-EXPORT_SYMBOL(disable_hlt);
-
-void enable_hlt(void)
-{
- hlt_counter--;
-}
-
-EXPORT_SYMBOL(enable_hlt);
-
-/*
- * We use this if we don't have any better
- * idle routine..
- */
-void default_idle(void)
-{
- if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
- 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 */
- else
- local_irq_enable();
- current_thread_info()->status |= TS_POLLING;
- } else {
- /* loop is done by the caller */
- cpu_relax();
- }
-}
-#ifdef CONFIG_APM_MODULE
-EXPORT_SYMBOL(default_idle);
-#endif
-
-/*
- * 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)
-{
- cpu_relax();
-}
-
-#ifdef CONFIG_HOTPLUG_CPU
-#include <asm/nmi.h>
-/* We don't actually take CPU down, just spin without interrupts. */
-static inline void play_dead(void)
-{
- /* This must be done before dead CPU ack */
- cpu_exit_clear();
- wbinvd();
- mb();
- /* Ack it */
- __get_cpu_var(cpu_state) = CPU_DEAD;
-
- /*
- * With physical CPU hotplug, we should halt the cpu
- */
- 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)
-{
- int cpu = smp_processor_id();
-
- current_thread_info()->status |= TS_POLLING;
-
- /* endless idle loop with no priority at all */
- while (1) {
- tick_nohz_stop_sched_tick();
- while (!need_resched()) {
- void (*idle)(void);
-
- if (__get_cpu_var(cpu_idle_state))
- __get_cpu_var(cpu_idle_state) = 0;
-
- check_pgt_cache();
- rmb();
- idle = pm_idle;
-
- if (!idle)
- idle = default_idle;
-
- if (cpu_is_offline(cpu))
- play_dead();
-
- __get_cpu_var(irq_stat).idle_timestamp = jiffies;
- idle();
- }
- tick_nohz_restart_sched_tick();
- preempt_enable_no_resched();
- schedule();
- preempt_disable();
- }
-}
-
-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);
- } 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 eax, unsigned long ecx)
-{
- if (!need_resched()) {
- __monitor((void *)¤t_thread_info()->flags, 0, 0);
- smp_mb();
- if (!need_resched())
- __mwait(eax, ecx);
- }
-}
-
-/* Default MONITOR/MWAIT with no hints, used for default C1 state */
-static void mwait_idle(void)
-{
- local_irq_enable();
- mwait_idle_with_hints(0, 0);
-}
-
-void __devinit select_idle_routine(const struct cpuinfo_x86 *c)
-{
- if (cpu_has(c, X86_FEATURE_MWAIT)) {
- printk("monitor/mwait feature present.\n");
- /*
- * Skip, if setup has overridden idle.
- * One CPU supports mwait => All CPUs supports mwait
- */
- if (!pm_idle) {
- printk("using mwait in idle threads.\n");
- 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;
-#ifdef CONFIG_X86_SMP
- if (smp_num_siblings > 1)
- printk("WARNING: polling idle and HT enabled, performance may degrade.\n");
-#endif
- } else if (!strcmp(str, "mwait"))
- force_mwait = 1;
- else
- return -1;
-
- boot_option_idle_override = 1;
- return 0;
-}
-early_param("idle", idle_setup);
-
-void show_regs(struct pt_regs * regs)
-{
- unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
- unsigned long d0, d1, d2, d3, d6, d7;
-
- printk("\n");
- printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
- printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id());
- print_symbol("EIP is at %s\n", regs->eip);
-
- if (user_mode_vm(regs))
- printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
- printk(" EFLAGS: %08lx %s (%s %.*s)\n",
- regs->eflags, print_tainted(), init_utsname()->release,
- (int)strcspn(init_utsname()->version, " "),
- init_utsname()->version);
- printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
- regs->eax,regs->ebx,regs->ecx,regs->edx);
- printk("ESI: %08lx EDI: %08lx EBP: %08lx",
- regs->esi, regs->edi, regs->ebp);
- printk(" DS: %04x ES: %04x FS: %04x\n",
- 0xffff & regs->xds,0xffff & regs->xes, 0xffff & regs->xfs);
-
- cr0 = read_cr0();
- cr2 = read_cr2();
- cr3 = read_cr3();
- cr4 = read_cr4_safe();
- printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
-
- get_debugreg(d0, 0);
- get_debugreg(d1, 1);
- get_debugreg(d2, 2);
- get_debugreg(d3, 3);
- printk("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
- d0, d1, d2, d3);
- get_debugreg(d6, 6);
- get_debugreg(d7, 7);
- printk("DR6: %08lx DR7: %08lx\n", d6, d7);
-
- show_trace(NULL, regs, ®s->esp);
-}
-
-/*
- * This gets run with %ebx containing the
- * function to call, and %edx 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(®s, 0, sizeof(regs));
-
- regs.ebx = (unsigned long) fn;
- regs.edx = (unsigned long) arg;
-
- regs.xds = __USER_DS;
- regs.xes = __USER_DS;
- regs.xfs = __KERNEL_PERCPU;
- regs.orig_eax = -1;
- regs.eip = (unsigned long) kernel_thread_helper;
- regs.xcs = __KERNEL_CS | get_kernel_rpl();
- regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2;
-
- /* Ok, create the new process.. */
- return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
-}
-EXPORT_SYMBOL(kernel_thread);
-
-/*
- * Free current thread data structures etc..
- */
-void exit_thread(void)
-{
- /* The process may have allocated an io port bitmap... nuke it. */
- if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
- struct task_struct *tsk = current;
- struct thread_struct *t = &tsk->thread;
- int cpu = get_cpu();
- struct tss_struct *tss = &per_cpu(init_tss, 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, tss->io_bitmap_max);
- t->io_bitmap_max = 0;
- tss->io_bitmap_owner = NULL;
- tss->io_bitmap_max = 0;
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
- put_cpu();
- }
-}
-
-void flush_thread(void)
-{
- struct task_struct *tsk = current;
-
- memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
- memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
- clear_tsk_thread_flag(tsk, TIF_DEBUG);
- /*
- * Forget coprocessor state..
- */
- clear_fpu(tsk);
- clear_used_math();
-}
-
-void release_thread(struct task_struct *dead_task)
-{
- BUG_ON(dead_task->mm);
- release_vm86_irqs(dead_task);
-}
-
-/*
- * 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 esp,
- unsigned long unused,
- struct task_struct * p, struct pt_regs * regs)
-{
- struct pt_regs * childregs;
- struct task_struct *tsk;
- int err;
-
- childregs = task_pt_regs(p);
- *childregs = *regs;
- childregs->eax = 0;
- childregs->esp = esp;
-
- p->thread.esp = (unsigned long) childregs;
- p->thread.esp0 = (unsigned long) (childregs+1);
-
- p->thread.eip = (unsigned long) ret_from_fork;
-
- savesegment(gs,p->thread.gs);
-
- tsk = current;
- if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
- p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
- IO_BITMAP_BYTES, GFP_KERNEL);
- if (!p->thread.io_bitmap_ptr) {
- p->thread.io_bitmap_max = 0;
- return -ENOMEM;
- }
- set_tsk_thread_flag(p, TIF_IO_BITMAP);
- }
-
- /*
- * Set a new TLS for the child thread?
- */
- if (clone_flags & CLONE_SETTLS) {
- struct desc_struct *desc;
- struct user_desc info;
- int idx;
-
- err = -EFAULT;
- if (copy_from_user(&info, (void __user *)childregs->esi, sizeof(info)))
- goto out;
- err = -EINVAL;
- if (LDT_empty(&info))
- goto out;
-
- idx = info.entry_number;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- goto out;
-
- desc = p->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
-
- err = 0;
- out:
- if (err && p->thread.io_bitmap_ptr) {
- kfree(p->thread.io_bitmap_ptr);
- p->thread.io_bitmap_max = 0;
- }
- return err;
-}
-
-/*
- * fill in the user structure for a core dump..
- */
-void dump_thread(struct pt_regs * regs, struct user * dump)
-{
- int i;
-
-/* changed the size calculations - should hopefully work better. lbt */
- dump->magic = CMAGIC;
- dump->start_code = 0;
- dump->start_stack = regs->esp & ~(PAGE_SIZE - 1);
- dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
- dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
- dump->u_dsize -= dump->u_tsize;
- dump->u_ssize = 0;
- for (i = 0; i < 8; i++)
- dump->u_debugreg[i] = current->thread.debugreg[i];
-
- if (dump->start_stack < TASK_SIZE)
- dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
-
- dump->regs.ebx = regs->ebx;
- dump->regs.ecx = regs->ecx;
- dump->regs.edx = regs->edx;
- dump->regs.esi = regs->esi;
- dump->regs.edi = regs->edi;
- dump->regs.ebp = regs->ebp;
- dump->regs.eax = regs->eax;
- dump->regs.ds = regs->xds;
- dump->regs.es = regs->xes;
- dump->regs.fs = regs->xfs;
- savesegment(gs,dump->regs.gs);
- dump->regs.orig_eax = regs->orig_eax;
- dump->regs.eip = regs->eip;
- dump->regs.cs = regs->xcs;
- dump->regs.eflags = regs->eflags;
- dump->regs.esp = regs->esp;
- dump->regs.ss = regs->xss;
-
- dump->u_fpvalid = dump_fpu (regs, &dump->i387);
-}
-EXPORT_SYMBOL(dump_thread);
-
-/*
- * 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 ptregs = *task_pt_regs(tsk);
- ptregs.xcs &= 0xffff;
- ptregs.xds &= 0xffff;
- ptregs.xes &= 0xffff;
- ptregs.xss &= 0xffff;
-
- elf_core_copy_regs(regs, &ptregs);
-
- return 1;
-}
-
-#ifdef CONFIG_SECCOMP
-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();
-}
-void hard_enable_TSC(void)
-{
- write_cr4(read_cr4() & ~X86_CR4_TSD);
-}
-#endif /* CONFIG_SECCOMP */
-
-static noinline void
-__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
- struct tss_struct *tss)
-{
- struct thread_struct *next;
-
- next = &next_p->thread;
-
- if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
- set_debugreg(next->debugreg[0], 0);
- set_debugreg(next->debugreg[1], 1);
- set_debugreg(next->debugreg[2], 2);
- set_debugreg(next->debugreg[3], 3);
- /* no 4 and 5 */
- set_debugreg(next->debugreg[6], 6);
- set_debugreg(next->debugreg[7], 7);
- }
-
-#ifdef CONFIG_SECCOMP
- 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();
- }
-#endif
-
- if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
- /*
- * Disable the bitmap via an invalid offset. We still cache
- * the previous bitmap owner and the IO bitmap contents:
- */
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
- return;
- }
-
- if (likely(next == tss->io_bitmap_owner)) {
- /*
- * Previous owner of the bitmap (hence the bitmap content)
- * matches the next task, we dont have to do anything but
- * to set a valid offset in the TSS:
- */
- tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
- return;
- }
- /*
- * Lazy TSS's I/O bitmap copy. We set an invalid offset here
- * and we let the task to get a GPF in case an I/O instruction
- * is performed. The handler of the GPF will verify that the
- * faulting task has a valid I/O bitmap and, it true, does the
- * real copy and restart the instruction. This will save us
- * redundant copies when the currently switched task does not
- * perform any I/O during its timeslice.
- */
- tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
-}
-
-/*
- * switch_to(x,yn) should switch tasks from x to y.
- *
- * We fsave/fwait so that an exception goes off at the right time
- * (as a call from the fsave or fwait in effect) rather than to
- * the wrong process. Lazy FP saving no longer makes any sense
- * with modern CPU's, and this simplifies a lot of things (SMP
- * and UP become the same).
- *
- * NOTE! We used to use the x86 hardware context switching. The
- * reason for not using it any more becomes apparent when you
- * try to recover gracefully from saved state that is no longer
- * valid (stale segment register values in particular). With the
- * hardware task-switch, there is no way to fix up bad state in
- * a reasonable manner.
- *
- * The fact that Intel documents the hardware task-switching to
- * be slow is a fairly red herring - this code is not noticeably
- * faster. However, there _is_ some room for improvement here,
- * so the performance issues may eventually be a valid point.
- * More important, however, is the fact that this allows us much
- * more flexibility.
- *
- * The return value (in %eax) will be the "prev" task after
- * the task-switch, and shows up in ret_from_fork in entry.S,
- * for example.
- */
-struct task_struct fastcall * __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);
-
- /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
-
- __unlazy_fpu(prev_p);
-
-
- /* we're going to use this soon, after a few expensive things */
- if (next_p->fpu_counter > 5)
- prefetch(&next->i387.fxsave);
-
- /*
- * Reload esp0.
- */
- load_esp0(tss, next);
-
- /*
- * Save away %gs. No need to save %fs, as it was saved on the
- * stack on entry. No need to save %es and %ds, as those are
- * always kernel segments while inside the kernel. Doing this
- * before setting the new TLS descriptors avoids the situation
- * where we temporarily have non-reloadable segments in %fs
- * and %gs. This could be an issue if the NMI handler ever
- * used %fs or %gs (it does not today), or if the kernel is
- * running inside of a hypervisor layer.
- */
- savesegment(gs, prev->gs);
-
- /*
- * Load the per-thread Thread-Local Storage descriptor.
- */
- load_TLS(next, cpu);
-
- /*
- * Restore IOPL if needed. In normal use, the flags restore
- * in the switch assembly will handle this. But if the kernel
- * is running virtualized at a non-zero CPL, the popf will
- * not restore flags, so it must be done in a separate step.
- */
- if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
- set_iopl_mask(next->iopl);
-
- /*
- * Now maybe handle debug registers and/or IO bitmaps
- */
- if (unlikely(task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV ||
- task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
- __switch_to_xtra(prev_p, next_p, tss);
-
- /*
- * 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.
- */
- arch_leave_lazy_cpu_mode();
-
- /* 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();
-
- /*
- * Restore %gs if needed (which is common)
- */
- if (prev->gs | next->gs)
- loadsegment(gs, next->gs);
-
- x86_write_percpu(current_task, next_p);
-
- return prev_p;
-}
-
-asmlinkage int sys_fork(struct pt_regs regs)
-{
- return do_fork(SIGCHLD, regs.esp, ®s, 0, NULL, NULL);
-}
-
-asmlinkage int sys_clone(struct pt_regs regs)
-{
- unsigned long clone_flags;
- unsigned long newsp;
- int __user *parent_tidptr, *child_tidptr;
-
- clone_flags = regs.ebx;
- newsp = regs.ecx;
- parent_tidptr = (int __user *)regs.edx;
- child_tidptr = (int __user *)regs.edi;
- if (!newsp)
- newsp = regs.esp;
- return do_fork(clone_flags, newsp, ®s, 0, parent_tidptr, child_tidptr);
-}
-
-/*
- * 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 int sys_vfork(struct pt_regs regs)
-{
- return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.esp, ®s, 0, NULL, NULL);
-}
-
-/*
- * sys_execve() executes a new program.
- */
-asmlinkage int sys_execve(struct pt_regs regs)
-{
- int error;
- char * filename;
-
- filename = getname((char __user *) regs.ebx);
- error = PTR_ERR(filename);
- if (IS_ERR(filename))
- goto out;
- error = do_execve(filename,
- (char __user * __user *) regs.ecx,
- (char __user * __user *) regs.edx,
- ®s);
- if (error == 0) {
- task_lock(current);
- current->ptrace &= ~PT_DTRACE;
- task_unlock(current);
- /* Make sure we don't return using sysenter.. */
- set_thread_flag(TIF_IRET);
- }
- putname(filename);
-out:
- return error;
-}
-
-#define top_esp (THREAD_SIZE - sizeof(unsigned long))
-#define top_ebp (THREAD_SIZE - 2*sizeof(unsigned long))
-
-unsigned long get_wchan(struct task_struct *p)
-{
- unsigned long ebp, esp, eip;
- unsigned long stack_page;
- int count = 0;
- if (!p || p == current || p->state == TASK_RUNNING)
- return 0;
- stack_page = (unsigned long)task_stack_page(p);
- esp = p->thread.esp;
- if (!stack_page || esp < stack_page || esp > top_esp+stack_page)
- return 0;
- /* include/asm-i386/system.h:switch_to() pushes ebp last. */
- ebp = *(unsigned long *) esp;
- do {
- if (ebp < stack_page || ebp > top_ebp+stack_page)
- return 0;
- eip = *(unsigned long *) (ebp+4);
- if (!in_sched_functions(eip))
- return eip;
- ebp = *(unsigned long *) ebp;
- } while (count++ < 16);
- return 0;
-}
-
-/*
- * sys_alloc_thread_area: get a yet unused TLS descriptor index.
- */
-static int get_free_idx(void)
-{
- struct thread_struct *t = ¤t->thread;
- int idx;
-
- for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
- if (desc_empty(t->tls_array + idx))
- return idx + GDT_ENTRY_TLS_MIN;
- return -ESRCH;
-}
-
-/*
- * Set a given TLS descriptor:
- */
-asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
-{
- struct thread_struct *t = ¤t->thread;
- struct user_desc info;
- struct desc_struct *desc;
- int cpu, idx;
-
- if (copy_from_user(&info, u_info, sizeof(info)))
- return -EFAULT;
- idx = info.entry_number;
-
- /*
- * index -1 means the kernel should try to find and
- * allocate an empty descriptor:
- */
- if (idx == -1) {
- idx = get_free_idx();
- if (idx < 0)
- return idx;
- if (put_user(idx, &u_info->entry_number))
- return -EFAULT;
- }
-
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- desc = t->tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- /*
- * We must not get preempted while modifying the TLS.
- */
- cpu = get_cpu();
-
- if (LDT_empty(&info)) {
- desc->a = 0;
- desc->b = 0;
- } else {
- desc->a = LDT_entry_a(&info);
- desc->b = LDT_entry_b(&info);
- }
- load_TLS(t, cpu);
-
- put_cpu();
-
- return 0;
-}
-
-/*
- * Get the current Thread-Local Storage area:
- */
-
-#define GET_BASE(desc) ( \
- (((desc)->a >> 16) & 0x0000ffff) | \
- (((desc)->b << 16) & 0x00ff0000) | \
- ( (desc)->b & 0xff000000) )
-
-#define GET_LIMIT(desc) ( \
- ((desc)->a & 0x0ffff) | \
- ((desc)->b & 0xf0000) )
-
-#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
-#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
-#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
-#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
-#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
-#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
-
-asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
-{
- struct user_desc info;
- struct desc_struct *desc;
- int idx;
-
- if (get_user(idx, &u_info->entry_number))
- return -EFAULT;
- if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
- return -EINVAL;
-
- memset(&info, 0, sizeof(info));
-
- desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
-
- info.entry_number = idx;
- info.base_addr = GET_BASE(desc);
- info.limit = GET_LIMIT(desc);
- info.seg_32bit = GET_32BIT(desc);
- info.contents = GET_CONTENTS(desc);
- info.read_exec_only = !GET_WRITABLE(desc);
- info.limit_in_pages = GET_LIMIT_PAGES(desc);
- info.seg_not_present = !GET_PRESENT(desc);
- info.useable = GET_USEABLE(desc);
-
- if (copy_to_user(u_info, &info, sizeof(info)))
- return -EFAULT;
- return 0;
-}
-
-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;
-}
--- /dev/null
+/*
+ * linux/arch/i386/kernel/process.c
+ *
+ * Copyright (C) 1995 Linus Torvalds
+ *
+ * Pentium III FXSR, SSE support
+ * Gareth Hughes <gareth@valinux.com>, May 2000
+ */
+
+/*
+ * 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/stddef.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/user.h>
+#include <linux/a.out.h>
+#include <linux/interrupt.h>
+#include <linux/utsname.h>
+#include <linux/delay.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/module.h>
+#include <linux/kallsyms.h>
+#include <linux/ptrace.h>
+#include <linux/random.h>
+#include <linux/personality.h>
+#include <linux/tick.h>
+#include <linux/percpu.h>
+
+#include <asm/uaccess.h>
+#include <asm/pgtable.h>
+#include <asm/system.h>
+#include <asm/io.h>
+#include <asm/ldt.h>
+#include <asm/processor.h>
+#include <asm/i387.h>
+#include <asm/desc.h>
+#include <asm/vm86.h>
+#ifdef CONFIG_MATH_EMULATION
+#include <asm/math_emu.h>
+#endif
+
+#include <linux/err.h>
+
+#include <asm/tlbflush.h>
+#include <asm/cpu.h>
+
+asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
+
+static int hlt_counter;
+
+unsigned long boot_option_idle_override = 0;
+EXPORT_SYMBOL(boot_option_idle_override);
+
+DEFINE_PER_CPU(struct task_struct *, current_task) = &init_task;
+EXPORT_PER_CPU_SYMBOL(current_task);
+
+DEFINE_PER_CPU(int, cpu_number);
+EXPORT_PER_CPU_SYMBOL(cpu_number);
+
+/*
+ * Return saved PC of a blocked thread.
+ */
+unsigned long thread_saved_pc(struct task_struct *tsk)
+{
+ return ((unsigned long *)tsk->thread.esp)[3];
+}
+
+/*
+ * Powermanagement idle function, if any..
+ */
+void (*pm_idle)(void);
+EXPORT_SYMBOL(pm_idle);
+static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
+
+void disable_hlt(void)
+{
+ hlt_counter++;
+}
+
+EXPORT_SYMBOL(disable_hlt);
+
+void enable_hlt(void)
+{
+ hlt_counter--;
+}
+
+EXPORT_SYMBOL(enable_hlt);
+
+/*
+ * We use this if we don't have any better
+ * idle routine..
+ */
+void default_idle(void)
+{
+ if (!hlt_counter && boot_cpu_data.hlt_works_ok) {
+ 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 */
+ else
+ local_irq_enable();
+ current_thread_info()->status |= TS_POLLING;
+ } else {
+ /* loop is done by the caller */
+ cpu_relax();
+ }
+}
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(default_idle);
+#endif
+
+/*
+ * 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)
+{
+ cpu_relax();
+}
+
+#ifdef CONFIG_HOTPLUG_CPU
+#include <asm/nmi.h>
+/* We don't actually take CPU down, just spin without interrupts. */
+static inline void play_dead(void)
+{
+ /* This must be done before dead CPU ack */
+ cpu_exit_clear();
+ wbinvd();
+ mb();
+ /* Ack it */
+ __get_cpu_var(cpu_state) = CPU_DEAD;
+
+ /*
+ * With physical CPU hotplug, we should halt the cpu
+ */
+ 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)
+{
+ int cpu = smp_processor_id();
+
+ current_thread_info()->status |= TS_POLLING;
+
+ /* endless idle loop with no priority at all */
+ while (1) {
+ tick_nohz_stop_sched_tick();
+ while (!need_resched()) {
+ void (*idle)(void);
+
+ if (__get_cpu_var(cpu_idle_state))
+ __get_cpu_var(cpu_idle_state) = 0;
+
+ check_pgt_cache();
+ rmb();
+ idle = pm_idle;
+
+ if (!idle)
+ idle = default_idle;
+
+ if (cpu_is_offline(cpu))
+ play_dead();
+
+ __get_cpu_var(irq_stat).idle_timestamp = jiffies;
+ idle();
+ }
+ tick_nohz_restart_sched_tick();
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+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);
+ } 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 eax, unsigned long ecx)
+{
+ if (!need_resched()) {
+ __monitor((void *)¤t_thread_info()->flags, 0, 0);
+ smp_mb();
+ if (!need_resched())
+ __mwait(eax, ecx);
+ }
+}
+
+/* Default MONITOR/MWAIT with no hints, used for default C1 state */
+static void mwait_idle(void)
+{
+ local_irq_enable();
+ mwait_idle_with_hints(0, 0);
+}
+
+void __devinit select_idle_routine(const struct cpuinfo_x86 *c)
+{
+ if (cpu_has(c, X86_FEATURE_MWAIT)) {
+ printk("monitor/mwait feature present.\n");
+ /*
+ * Skip, if setup has overridden idle.
+ * One CPU supports mwait => All CPUs supports mwait
+ */
+ if (!pm_idle) {
+ printk("using mwait in idle threads.\n");
+ 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;
+#ifdef CONFIG_X86_SMP
+ if (smp_num_siblings > 1)
+ printk("WARNING: polling idle and HT enabled, performance may degrade.\n");
+#endif
+ } else if (!strcmp(str, "mwait"))
+ force_mwait = 1;
+ else
+ return -1;
+
+ boot_option_idle_override = 1;
+ return 0;
+}
+early_param("idle", idle_setup);
+
+void show_regs(struct pt_regs * regs)
+{
+ unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
+ unsigned long d0, d1, d2, d3, d6, d7;
+
+ printk("\n");
+ printk("Pid: %d, comm: %20s\n", current->pid, current->comm);
+ printk("EIP: %04x:[<%08lx>] CPU: %d\n",0xffff & regs->xcs,regs->eip, smp_processor_id());
+ print_symbol("EIP is at %s\n", regs->eip);
+
+ if (user_mode_vm(regs))
+ printk(" ESP: %04x:%08lx",0xffff & regs->xss,regs->esp);
+ printk(" EFLAGS: %08lx %s (%s %.*s)\n",
+ regs->eflags, print_tainted(), init_utsname()->release,
+ (int)strcspn(init_utsname()->version, " "),
+ init_utsname()->version);
+ printk("EAX: %08lx EBX: %08lx ECX: %08lx EDX: %08lx\n",
+ regs->eax,regs->ebx,regs->ecx,regs->edx);
+ printk("ESI: %08lx EDI: %08lx EBP: %08lx",
+ regs->esi, regs->edi, regs->ebp);
+ printk(" DS: %04x ES: %04x FS: %04x\n",
+ 0xffff & regs->xds,0xffff & regs->xes, 0xffff & regs->xfs);
+
+ cr0 = read_cr0();
+ cr2 = read_cr2();
+ cr3 = read_cr3();
+ cr4 = read_cr4_safe();
+ printk("CR0: %08lx CR2: %08lx CR3: %08lx CR4: %08lx\n", cr0, cr2, cr3, cr4);
+
+ get_debugreg(d0, 0);
+ get_debugreg(d1, 1);
+ get_debugreg(d2, 2);
+ get_debugreg(d3, 3);
+ printk("DR0: %08lx DR1: %08lx DR2: %08lx DR3: %08lx\n",
+ d0, d1, d2, d3);
+ get_debugreg(d6, 6);
+ get_debugreg(d7, 7);
+ printk("DR6: %08lx DR7: %08lx\n", d6, d7);
+
+ show_trace(NULL, regs, ®s->esp);
+}
+
+/*
+ * This gets run with %ebx containing the
+ * function to call, and %edx 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(®s, 0, sizeof(regs));
+
+ regs.ebx = (unsigned long) fn;
+ regs.edx = (unsigned long) arg;
+
+ regs.xds = __USER_DS;
+ regs.xes = __USER_DS;
+ regs.xfs = __KERNEL_PERCPU;
+ regs.orig_eax = -1;
+ regs.eip = (unsigned long) kernel_thread_helper;
+ regs.xcs = __KERNEL_CS | get_kernel_rpl();
+ regs.eflags = X86_EFLAGS_IF | X86_EFLAGS_SF | X86_EFLAGS_PF | 0x2;
+
+ /* Ok, create the new process.. */
+ return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, ®s, 0, NULL, NULL);
+}
+EXPORT_SYMBOL(kernel_thread);
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+ /* The process may have allocated an io port bitmap... nuke it. */
+ if (unlikely(test_thread_flag(TIF_IO_BITMAP))) {
+ struct task_struct *tsk = current;
+ struct thread_struct *t = &tsk->thread;
+ int cpu = get_cpu();
+ struct tss_struct *tss = &per_cpu(init_tss, 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, tss->io_bitmap_max);
+ t->io_bitmap_max = 0;
+ tss->io_bitmap_owner = NULL;
+ tss->io_bitmap_max = 0;
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+ put_cpu();
+ }
+}
+
+void flush_thread(void)
+{
+ struct task_struct *tsk = current;
+
+ memset(tsk->thread.debugreg, 0, sizeof(unsigned long)*8);
+ memset(tsk->thread.tls_array, 0, sizeof(tsk->thread.tls_array));
+ clear_tsk_thread_flag(tsk, TIF_DEBUG);
+ /*
+ * Forget coprocessor state..
+ */
+ clear_fpu(tsk);
+ clear_used_math();
+}
+
+void release_thread(struct task_struct *dead_task)
+{
+ BUG_ON(dead_task->mm);
+ release_vm86_irqs(dead_task);
+}
+
+/*
+ * 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 esp,
+ unsigned long unused,
+ struct task_struct * p, struct pt_regs * regs)
+{
+ struct pt_regs * childregs;
+ struct task_struct *tsk;
+ int err;
+
+ childregs = task_pt_regs(p);
+ *childregs = *regs;
+ childregs->eax = 0;
+ childregs->esp = esp;
+
+ p->thread.esp = (unsigned long) childregs;
+ p->thread.esp0 = (unsigned long) (childregs+1);
+
+ p->thread.eip = (unsigned long) ret_from_fork;
+
+ savesegment(gs,p->thread.gs);
+
+ tsk = current;
+ if (unlikely(test_tsk_thread_flag(tsk, TIF_IO_BITMAP))) {
+ p->thread.io_bitmap_ptr = kmemdup(tsk->thread.io_bitmap_ptr,
+ IO_BITMAP_BYTES, GFP_KERNEL);
+ if (!p->thread.io_bitmap_ptr) {
+ p->thread.io_bitmap_max = 0;
+ return -ENOMEM;
+ }
+ set_tsk_thread_flag(p, TIF_IO_BITMAP);
+ }
+
+ /*
+ * Set a new TLS for the child thread?
+ */
+ if (clone_flags & CLONE_SETTLS) {
+ struct desc_struct *desc;
+ struct user_desc info;
+ int idx;
+
+ err = -EFAULT;
+ if (copy_from_user(&info, (void __user *)childregs->esi, sizeof(info)))
+ goto out;
+ err = -EINVAL;
+ if (LDT_empty(&info))
+ goto out;
+
+ idx = info.entry_number;
+ if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+ goto out;
+
+ desc = p->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
+ desc->a = LDT_entry_a(&info);
+ desc->b = LDT_entry_b(&info);
+ }
+
+ err = 0;
+ out:
+ if (err && p->thread.io_bitmap_ptr) {
+ kfree(p->thread.io_bitmap_ptr);
+ p->thread.io_bitmap_max = 0;
+ }
+ return err;
+}
+
+/*
+ * fill in the user structure for a core dump..
+ */
+void dump_thread(struct pt_regs * regs, struct user * dump)
+{
+ int i;
+
+/* changed the size calculations - should hopefully work better. lbt */
+ dump->magic = CMAGIC;
+ dump->start_code = 0;
+ dump->start_stack = regs->esp & ~(PAGE_SIZE - 1);
+ dump->u_tsize = ((unsigned long) current->mm->end_code) >> PAGE_SHIFT;
+ dump->u_dsize = ((unsigned long) (current->mm->brk + (PAGE_SIZE-1))) >> PAGE_SHIFT;
+ dump->u_dsize -= dump->u_tsize;
+ dump->u_ssize = 0;
+ for (i = 0; i < 8; i++)
+ dump->u_debugreg[i] = current->thread.debugreg[i];
+
+ if (dump->start_stack < TASK_SIZE)
+ dump->u_ssize = ((unsigned long) (TASK_SIZE - dump->start_stack)) >> PAGE_SHIFT;
+
+ dump->regs.ebx = regs->ebx;
+ dump->regs.ecx = regs->ecx;
+ dump->regs.edx = regs->edx;
+ dump->regs.esi = regs->esi;
+ dump->regs.edi = regs->edi;
+ dump->regs.ebp = regs->ebp;
+ dump->regs.eax = regs->eax;
+ dump->regs.ds = regs->xds;
+ dump->regs.es = regs->xes;
+ dump->regs.fs = regs->xfs;
+ savesegment(gs,dump->regs.gs);
+ dump->regs.orig_eax = regs->orig_eax;
+ dump->regs.eip = regs->eip;
+ dump->regs.cs = regs->xcs;
+ dump->regs.eflags = regs->eflags;
+ dump->regs.esp = regs->esp;
+ dump->regs.ss = regs->xss;
+
+ dump->u_fpvalid = dump_fpu (regs, &dump->i387);
+}
+EXPORT_SYMBOL(dump_thread);
+
+/*
+ * 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 ptregs = *task_pt_regs(tsk);
+ ptregs.xcs &= 0xffff;
+ ptregs.xds &= 0xffff;
+ ptregs.xes &= 0xffff;
+ ptregs.xss &= 0xffff;
+
+ elf_core_copy_regs(regs, &ptregs);
+
+ return 1;
+}
+
+#ifdef CONFIG_SECCOMP
+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();
+}
+void hard_enable_TSC(void)
+{
+ write_cr4(read_cr4() & ~X86_CR4_TSD);
+}
+#endif /* CONFIG_SECCOMP */
+
+static noinline void
+__switch_to_xtra(struct task_struct *prev_p, struct task_struct *next_p,
+ struct tss_struct *tss)
+{
+ struct thread_struct *next;
+
+ next = &next_p->thread;
+
+ if (test_tsk_thread_flag(next_p, TIF_DEBUG)) {
+ set_debugreg(next->debugreg[0], 0);
+ set_debugreg(next->debugreg[1], 1);
+ set_debugreg(next->debugreg[2], 2);
+ set_debugreg(next->debugreg[3], 3);
+ /* no 4 and 5 */
+ set_debugreg(next->debugreg[6], 6);
+ set_debugreg(next->debugreg[7], 7);
+ }
+
+#ifdef CONFIG_SECCOMP
+ 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();
+ }
+#endif
+
+ if (!test_tsk_thread_flag(next_p, TIF_IO_BITMAP)) {
+ /*
+ * Disable the bitmap via an invalid offset. We still cache
+ * the previous bitmap owner and the IO bitmap contents:
+ */
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET;
+ return;
+ }
+
+ if (likely(next == tss->io_bitmap_owner)) {
+ /*
+ * Previous owner of the bitmap (hence the bitmap content)
+ * matches the next task, we dont have to do anything but
+ * to set a valid offset in the TSS:
+ */
+ tss->x86_tss.io_bitmap_base = IO_BITMAP_OFFSET;
+ return;
+ }
+ /*
+ * Lazy TSS's I/O bitmap copy. We set an invalid offset here
+ * and we let the task to get a GPF in case an I/O instruction
+ * is performed. The handler of the GPF will verify that the
+ * faulting task has a valid I/O bitmap and, it true, does the
+ * real copy and restart the instruction. This will save us
+ * redundant copies when the currently switched task does not
+ * perform any I/O during its timeslice.
+ */
+ tss->x86_tss.io_bitmap_base = INVALID_IO_BITMAP_OFFSET_LAZY;
+}
+
+/*
+ * switch_to(x,yn) should switch tasks from x to y.
+ *
+ * We fsave/fwait so that an exception goes off at the right time
+ * (as a call from the fsave or fwait in effect) rather than to
+ * the wrong process. Lazy FP saving no longer makes any sense
+ * with modern CPU's, and this simplifies a lot of things (SMP
+ * and UP become the same).
+ *
+ * NOTE! We used to use the x86 hardware context switching. The
+ * reason for not using it any more becomes apparent when you
+ * try to recover gracefully from saved state that is no longer
+ * valid (stale segment register values in particular). With the
+ * hardware task-switch, there is no way to fix up bad state in
+ * a reasonable manner.
+ *
+ * The fact that Intel documents the hardware task-switching to
+ * be slow is a fairly red herring - this code is not noticeably
+ * faster. However, there _is_ some room for improvement here,
+ * so the performance issues may eventually be a valid point.
+ * More important, however, is the fact that this allows us much
+ * more flexibility.
+ *
+ * The return value (in %eax) will be the "prev" task after
+ * the task-switch, and shows up in ret_from_fork in entry.S,
+ * for example.
+ */
+struct task_struct fastcall * __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);
+
+ /* never put a printk in __switch_to... printk() calls wake_up*() indirectly */
+
+ __unlazy_fpu(prev_p);
+
+
+ /* we're going to use this soon, after a few expensive things */
+ if (next_p->fpu_counter > 5)
+ prefetch(&next->i387.fxsave);
+
+ /*
+ * Reload esp0.
+ */
+ load_esp0(tss, next);
+
+ /*
+ * Save away %gs. No need to save %fs, as it was saved on the
+ * stack on entry. No need to save %es and %ds, as those are
+ * always kernel segments while inside the kernel. Doing this
+ * before setting the new TLS descriptors avoids the situation
+ * where we temporarily have non-reloadable segments in %fs
+ * and %gs. This could be an issue if the NMI handler ever
+ * used %fs or %gs (it does not today), or if the kernel is
+ * running inside of a hypervisor layer.
+ */
+ savesegment(gs, prev->gs);
+
+ /*
+ * Load the per-thread Thread-Local Storage descriptor.
+ */
+ load_TLS(next, cpu);
+
+ /*
+ * Restore IOPL if needed. In normal use, the flags restore
+ * in the switch assembly will handle this. But if the kernel
+ * is running virtualized at a non-zero CPL, the popf will
+ * not restore flags, so it must be done in a separate step.
+ */
+ if (get_kernel_rpl() && unlikely(prev->iopl != next->iopl))
+ set_iopl_mask(next->iopl);
+
+ /*
+ * Now maybe handle debug registers and/or IO bitmaps
+ */
+ if (unlikely(task_thread_info(prev_p)->flags & _TIF_WORK_CTXSW_PREV ||
+ task_thread_info(next_p)->flags & _TIF_WORK_CTXSW_NEXT))
+ __switch_to_xtra(prev_p, next_p, tss);
+
+ /*
+ * 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.
+ */
+ arch_leave_lazy_cpu_mode();
+
+ /* 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();
+
+ /*
+ * Restore %gs if needed (which is common)
+ */
+ if (prev->gs | next->gs)
+ loadsegment(gs, next->gs);
+
+ x86_write_percpu(current_task, next_p);
+
+ return prev_p;
+}
+
+asmlinkage int sys_fork(struct pt_regs regs)
+{
+ return do_fork(SIGCHLD, regs.esp, ®s, 0, NULL, NULL);
+}
+
+asmlinkage int sys_clone(struct pt_regs regs)
+{
+ unsigned long clone_flags;
+ unsigned long newsp;
+ int __user *parent_tidptr, *child_tidptr;
+
+ clone_flags = regs.ebx;
+ newsp = regs.ecx;
+ parent_tidptr = (int __user *)regs.edx;
+ child_tidptr = (int __user *)regs.edi;
+ if (!newsp)
+ newsp = regs.esp;
+ return do_fork(clone_flags, newsp, ®s, 0, parent_tidptr, child_tidptr);
+}
+
+/*
+ * 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 int sys_vfork(struct pt_regs regs)
+{
+ return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs.esp, ®s, 0, NULL, NULL);
+}
+
+/*
+ * sys_execve() executes a new program.
+ */
+asmlinkage int sys_execve(struct pt_regs regs)
+{
+ int error;
+ char * filename;
+
+ filename = getname((char __user *) regs.ebx);
+ error = PTR_ERR(filename);
+ if (IS_ERR(filename))
+ goto out;
+ error = do_execve(filename,
+ (char __user * __user *) regs.ecx,
+ (char __user * __user *) regs.edx,
+ ®s);
+ if (error == 0) {
+ task_lock(current);
+ current->ptrace &= ~PT_DTRACE;
+ task_unlock(current);
+ /* Make sure we don't return using sysenter.. */
+ set_thread_flag(TIF_IRET);
+ }
+ putname(filename);
+out:
+ return error;
+}
+
+#define top_esp (THREAD_SIZE - sizeof(unsigned long))
+#define top_ebp (THREAD_SIZE - 2*sizeof(unsigned long))
+
+unsigned long get_wchan(struct task_struct *p)
+{
+ unsigned long ebp, esp, eip;
+ unsigned long stack_page;
+ int count = 0;
+ if (!p || p == current || p->state == TASK_RUNNING)
+ return 0;
+ stack_page = (unsigned long)task_stack_page(p);
+ esp = p->thread.esp;
+ if (!stack_page || esp < stack_page || esp > top_esp+stack_page)
+ return 0;
+ /* include/asm-i386/system.h:switch_to() pushes ebp last. */
+ ebp = *(unsigned long *) esp;
+ do {
+ if (ebp < stack_page || ebp > top_ebp+stack_page)
+ return 0;
+ eip = *(unsigned long *) (ebp+4);
+ if (!in_sched_functions(eip))
+ return eip;
+ ebp = *(unsigned long *) ebp;
+ } while (count++ < 16);
+ return 0;
+}
+
+/*
+ * sys_alloc_thread_area: get a yet unused TLS descriptor index.
+ */
+static int get_free_idx(void)
+{
+ struct thread_struct *t = ¤t->thread;
+ int idx;
+
+ for (idx = 0; idx < GDT_ENTRY_TLS_ENTRIES; idx++)
+ if (desc_empty(t->tls_array + idx))
+ return idx + GDT_ENTRY_TLS_MIN;
+ return -ESRCH;
+}
+
+/*
+ * Set a given TLS descriptor:
+ */
+asmlinkage int sys_set_thread_area(struct user_desc __user *u_info)
+{
+ struct thread_struct *t = ¤t->thread;
+ struct user_desc info;
+ struct desc_struct *desc;
+ int cpu, idx;
+
+ if (copy_from_user(&info, u_info, sizeof(info)))
+ return -EFAULT;
+ idx = info.entry_number;
+
+ /*
+ * index -1 means the kernel should try to find and
+ * allocate an empty descriptor:
+ */
+ if (idx == -1) {
+ idx = get_free_idx();
+ if (idx < 0)
+ return idx;
+ if (put_user(idx, &u_info->entry_number))
+ return -EFAULT;
+ }
+
+ if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+ return -EINVAL;
+
+ desc = t->tls_array + idx - GDT_ENTRY_TLS_MIN;
+
+ /*
+ * We must not get preempted while modifying the TLS.
+ */
+ cpu = get_cpu();
+
+ if (LDT_empty(&info)) {
+ desc->a = 0;
+ desc->b = 0;
+ } else {
+ desc->a = LDT_entry_a(&info);
+ desc->b = LDT_entry_b(&info);
+ }
+ load_TLS(t, cpu);
+
+ put_cpu();
+
+ return 0;
+}
+
+/*
+ * Get the current Thread-Local Storage area:
+ */
+
+#define GET_BASE(desc) ( \
+ (((desc)->a >> 16) & 0x0000ffff) | \
+ (((desc)->b << 16) & 0x00ff0000) | \
+ ( (desc)->b & 0xff000000) )
+
+#define GET_LIMIT(desc) ( \
+ ((desc)->a & 0x0ffff) | \
+ ((desc)->b & 0xf0000) )
+
+#define GET_32BIT(desc) (((desc)->b >> 22) & 1)
+#define GET_CONTENTS(desc) (((desc)->b >> 10) & 3)
+#define GET_WRITABLE(desc) (((desc)->b >> 9) & 1)
+#define GET_LIMIT_PAGES(desc) (((desc)->b >> 23) & 1)
+#define GET_PRESENT(desc) (((desc)->b >> 15) & 1)
+#define GET_USEABLE(desc) (((desc)->b >> 20) & 1)
+
+asmlinkage int sys_get_thread_area(struct user_desc __user *u_info)
+{
+ struct user_desc info;
+ struct desc_struct *desc;
+ int idx;
+
+ if (get_user(idx, &u_info->entry_number))
+ return -EFAULT;
+ if (idx < GDT_ENTRY_TLS_MIN || idx > GDT_ENTRY_TLS_MAX)
+ return -EINVAL;
+
+ memset(&info, 0, sizeof(info));
+
+ desc = current->thread.tls_array + idx - GDT_ENTRY_TLS_MIN;
+
+ info.entry_number = idx;
+ info.base_addr = GET_BASE(desc);
+ info.limit = GET_LIMIT(desc);
+ info.seg_32bit = GET_32BIT(desc);
+ info.contents = GET_CONTENTS(desc);
+ info.read_exec_only = !GET_WRITABLE(desc);
+ info.limit_in_pages = GET_LIMIT_PAGES(desc);
+ info.seg_not_present = !GET_PRESENT(desc);
+ info.useable = GET_USEABLE(desc);
+
+ if (copy_to_user(u_info, &info, sizeof(info)))
+ return -EFAULT;
+ return 0;
+}
+
+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;
+}
projects / deliverable / linux.git / commitdiff
