X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;ds=sidebyside;f=arch%2Fi386%2Fkernel%2Fprocess-xen.c;fp=arch%2Fi386%2Fkernel%2Fprocess-xen.c;h=0c2fdcc1912eddc269511cd429c42cea3545a121;hb=1db395853d4f30d6120458bd279ede1f882a8525;hp=0000000000000000000000000000000000000000;hpb=34a75f0025b9cf803b6a88db032e6ad6950c9313;p=linux-2.6.git diff --git a/arch/i386/kernel/process-xen.c b/arch/i386/kernel/process-xen.c new file mode 100644 index 000000000..0c2fdcc19 --- /dev/null +++ b/arch/i386/kernel/process-xen.c @@ -0,0 +1,870 @@ +/* + * linux/arch/i386/kernel/process.c + * + * Copyright (C) 1995 Linus Torvalds + * + * Pentium III FXSR, SSE support + * Gareth Hughes , May 2000 + */ + +/* + * This file handles the architecture-dependent parts of process handling.. + */ + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#ifdef CONFIG_MATH_EMULATION +#include +#endif + +#include +#include +#include + +#include + +#include +#include + +#include +#include + +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; +} +