--- /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/smp_lock.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/config.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 <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 <xen/interface/physdev.h>
+#include <xen/interface/vcpu.h>
+#include <xen/cpu_hotplug.h>
+
+#include <linux/err.h>
+
+#include <asm/tlbflush.h>
+#include <asm/cpu.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);
+
+/*
+ * 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);
+
+/* XXX XEN doesn't use default_idle(), poll_idle(). Use xen_idle() instead. */
+void xen_idle(void)
+{
+ local_irq_disable();
+
+ if (need_resched())
+ local_irq_enable();
+ else {
+ clear_thread_flag(TIF_POLLING_NRFLAG);
+ smp_mb__after_clear_bit();
+ safe_halt();
+ set_thread_flag(TIF_POLLING_NRFLAG);
+ }
+}
+#ifdef CONFIG_APM_MODULE
+EXPORT_SYMBOL(default_idle);
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+extern cpumask_t cpu_initialized;
+static inline void play_dead(void)
+{
+ idle_task_exit();
+ local_irq_disable();
+ cpu_clear(smp_processor_id(), cpu_initialized);
+ preempt_enable_no_resched();
+ HYPERVISOR_vcpu_op(VCPUOP_down, smp_processor_id(), NULL);
+ cpu_bringup();
+}
+#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();
+
+ set_thread_flag(TIF_POLLING_NRFLAG);
+
+ /* endless idle loop with no priority at all */
+ while (1) {
+ while (!need_resched()) {
+
+ if (__get_cpu_var(cpu_idle_state))
+ __get_cpu_var(cpu_idle_state) = 0;
+
+ rmb();
+
+ if (cpu_is_offline(cpu))
+ play_dead();
+
+ __get_cpu_var(irq_stat).idle_timestamp = jiffies;
+ xen_idle();
+ }
+ preempt_enable_no_resched();
+ schedule();
+ preempt_disable();
+ }
+}
+
+void cpu_idle_wait(void)
+{
+ unsigned int cpu, this_cpu = get_cpu();
+ cpumask_t map;
+
+ 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));
+}
+EXPORT_SYMBOL_GPL(cpu_idle_wait);
+
+/* XXX XEN doesn't use mwait_idle(), select_idle_routine(), idle_setup(). */
+/* Always use xen_idle() instead. */
+void __devinit select_idle_routine(const struct cpuinfo_x86 *c) {}
+
+void show_regs(struct pt_regs * regs)
+{
+ unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;
+
+ 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(), system_utsname.release,
+ (int)strcspn(system_utsname.version, " "),
+ system_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\n",
+ 0xffff & regs->xds,0xffff & regs->xes);
+
+ 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);
+ show_trace(NULL, ®s->esp);
+}
+
+/*
+ * This gets run with %ebx containing the
+ * function to call, and %edx containing
+ * the "args".
+ */
+extern void kernel_thread_helper(void);
+__asm__(".section .text\n"
+ ".align 4\n"
+ "kernel_thread_helper:\n\t"
+ "movl %edx,%eax\n\t"
+ "pushl %edx\n\t"
+ "call *%ebx\n\t"
+ "pushl %eax\n\t"
+ "call do_exit\n"
+ ".previous");
+
+/*
+ * 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.orig_eax = -1;
+ regs.eip = (unsigned long) kernel_thread_helper;
+ regs.xcs = GET_KERNEL_CS();
+ 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)
+{
+ struct task_struct *tsk = current;
+ struct thread_struct *t = &tsk->thread;
+
+ /* The process may have allocated an io port bitmap... nuke it. */
+ if (unlikely(NULL != t->io_bitmap_ptr)) {
+ struct physdev_set_iobitmap set_iobitmap = { 0 };
+ HYPERVISOR_physdev_op(PHYSDEVOP_set_iobitmap, &set_iobitmap);
+ kfree(t->io_bitmap_ptr);
+ t->io_bitmap_ptr = NULL;
+ }
+}
+
+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));
+ /*
+ * 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(fs,p->thread.fs);
+ savesegment(gs,p->thread.gs);
+
+ tsk = current;
+ if (unlikely(NULL != tsk->thread.io_bitmap_ptr)) {
+ 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, tsk->thread.io_bitmap_ptr,
+ IO_BITMAP_BYTES);
+ }
+
+ /*
+ * 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);
+ }
+
+ p->thread.iopl = current->thread.iopl;
+
+ 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;
+ savesegment(fs,dump->regs.fs);
+ 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;
+}
+
+/*
+ * This function selects if the context switch from prev to next
+ * has to tweak the TSC disable bit in the cr4.
+ */
+static inline void disable_tsc(struct task_struct *prev_p,
+ struct task_struct *next_p)
+{
+ struct thread_info *prev, *next;
+
+ /*
+ * gcc should eliminate the ->thread_info dereference if
+ * has_secure_computing returns 0 at compile time (SECCOMP=n).
+ */
+ prev = task_thread_info(prev_p);
+ next = task_thread_info(next_p);
+
+ if (has_secure_computing(prev) || has_secure_computing(next)) {
+ /* slow path here */
+ if (has_secure_computing(prev) &&
+ !has_secure_computing(next)) {
+ write_cr4(read_cr4() & ~X86_CR4_TSD);
+ } else if (!has_secure_computing(prev) &&
+ has_secure_computing(next))
+ write_cr4(read_cr4() | X86_CR4_TSD);
+ }
+}
+
+/*
+ * 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();
+#ifndef CONFIG_X86_NO_TSS
+ struct tss_struct *tss = &per_cpu(init_tss, cpu);
+#endif
+ struct physdev_set_iopl iopl_op;
+ struct physdev_set_iobitmap iobmp_op;
+ multicall_entry_t _mcl[8], *mcl = _mcl;
+
+ /* XEN NOTE: FS/GS saved in switch_mm(), not here. */
+
+ /*
+ * This is basically '__unlazy_fpu', except that we queue a
+ * multicall to indicate FPU task switch, rather than
+ * synchronously trapping to Xen.
+ */
+ if (prev_p->thread_info->status & TS_USEDFPU) {
+ __save_init_fpu(prev_p); /* _not_ save_init_fpu() */
+ mcl->op = __HYPERVISOR_fpu_taskswitch;
+ mcl->args[0] = 1;
+ mcl++;
+ }
+#if 0 /* lazy fpu sanity check */
+ else BUG_ON(!(read_cr0() & 8));
+#endif
+ if (next_p->mm)
+ load_user_cs_desc(cpu, next_p->mm);
+
+ /*
+ * Reload esp0.
+ * This is load_esp0(tss, next) with a multicall.
+ */
+ mcl->op = __HYPERVISOR_stack_switch;
+ mcl->args[0] = __KERNEL_DS;
+ mcl->args[1] = next->esp0;
+ mcl++;
+
+ /*
+ * Load the per-thread Thread-Local Storage descriptor.
+ * This is load_TLS(next, cpu) with multicalls.
+ */
+#define C(i) do { \
+ if (unlikely(next->tls_array[i].a != prev->tls_array[i].a || \
+ next->tls_array[i].b != prev->tls_array[i].b)) { \
+ mcl->op = __HYPERVISOR_update_descriptor; \
+ *(u64 *)&mcl->args[0] = virt_to_machine( \
+ &get_cpu_gdt_table(cpu)[GDT_ENTRY_TLS_MIN + i]);\
+ *(u64 *)&mcl->args[2] = *(u64 *)&next->tls_array[i]; \
+ mcl++; \
+ } \
+} while (0)
+ C(0); C(1); C(2);
+#undef C
+
+ if (unlikely(prev->iopl != next->iopl)) {
+ iopl_op.iopl = (next->iopl == 0) ? 1 : (next->iopl >> 12) & 3;
+ mcl->op = __HYPERVISOR_physdev_op;
+ mcl->args[0] = PHYSDEVOP_set_iopl;
+ mcl->args[1] = (unsigned long)&iopl_op;
+ mcl++;
+ }
+
+ if (unlikely(prev->io_bitmap_ptr || next->io_bitmap_ptr)) {
+ iobmp_op.bitmap = (char *)next->io_bitmap_ptr;
+ iobmp_op.nr_ports = next->io_bitmap_ptr ? IO_BITMAP_BITS : 0;
+ mcl->op = __HYPERVISOR_physdev_op;
+ mcl->args[0] = PHYSDEVOP_set_iobitmap;
+ mcl->args[1] = (unsigned long)&iobmp_op;
+ mcl++;
+ }
+
+ (void)HYPERVISOR_multicall(_mcl, mcl - _mcl);
+
+ /*
+ * Restore %fs and %gs if needed.
+ *
+ * Glibc normally makes %fs be zero, and %gs is one of
+ * the TLS segments.
+ */
+ if (unlikely(next->fs))
+ loadsegment(fs, next->fs);
+
+ if (next->gs)
+ loadsegment(gs, next->gs);
+
+ /*
+ * Now maybe reload the debug registers
+ */
+ if (unlikely(next->debugreg[7])) {
+ 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);
+ }
+
+ disable_tsc(prev_p, 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 (randomize_va_space)
+ sp -= get_random_int() % 8192;
+ return sp & ~0xf;
+}
+
+void arch_add_exec_range(struct mm_struct *mm, unsigned long limit)
+{
+ if (limit > mm->context.exec_limit) {
+ mm->context.exec_limit = limit;
+ set_user_cs(&mm->context.user_cs, limit);
+ if (mm == current->mm) {
+ preempt_disable();
+ load_user_cs_desc(smp_processor_id(), mm);
+ preempt_enable();
+ }
+ }
+}
+void arch_remove_exec_range(struct mm_struct *mm, unsigned long old_end)
+{
+ struct vm_area_struct *vma;
+ unsigned long limit = PAGE_SIZE;
+
+ if (old_end == mm->context.exec_limit) {
+ for (vma = mm->mmap; vma; vma = vma->vm_next)
+ if ((vma->vm_flags & VM_EXEC) && (vma->vm_end > limit))
+ limit = vma->vm_end;
+
+ mm->context.exec_limit = limit;
+ set_user_cs(&mm->context.user_cs, limit);
+ if (mm == current->mm) {
+ preempt_disable();
+ load_user_cs_desc(smp_processor_id(), mm);
+ preempt_enable();
+ }
+ }
+}
+
+void arch_flush_exec_range(struct mm_struct *mm)
+{
+ mm->context.exec_limit = 0;
+ set_user_cs(&mm->context.user_cs, 0);
+}
+
+/*
+ * Generate random brk address between 128MB and 196MB. (if the layout
+ * allows it.)
+ */
+void randomize_brk(unsigned long old_brk)
+{
+ unsigned long new_brk, range_start, range_end;
+
+ range_start = 0x08000000;
+ if (current->mm->brk >= range_start)
+ range_start = current->mm->brk;
+ range_end = range_start + 0x02000000;
+ new_brk = randomize_range(range_start, range_end, 0);
+ if (new_brk)
+ current->mm->brk = new_brk;
+}
+
git://git.onelab.eu / linux-2.6.git / blobdiff