X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Fsysenter.c;fp=arch%2Fi386%2Fkernel%2Fsysenter.c;h=0bada1870bdf5691631e10558bf43cbb350691a1;hb=64ba3f394c830ec48a1c31b53dcae312c56f1604;hp=0c3a3f9b5483f99aeab3c8dc732b3f257ab6d1d7;hpb=be1e6109ac94a859551f8e1774eb9a8469fe055c;p=linux-2.6.git diff --git a/arch/i386/kernel/sysenter.c b/arch/i386/kernel/sysenter.c index 0c3a3f9b5..0bada1870 100644 --- a/arch/i386/kernel/sysenter.c +++ b/arch/i386/kernel/sysenter.c @@ -2,8 +2,6 @@ * linux/arch/i386/kernel/sysenter.c * * (C) Copyright 2002 Linus Torvalds - * Portions based on the vdso-randomization code from exec-shield: - * Copyright(C) 2005-2006, Red Hat, Inc., Ingo Molnar * * This file contains the needed initializations to support sysenter. */ @@ -15,42 +13,16 @@ #include #include #include -#include -#include -#include -#include #include #include #include #include -#ifdef CONFIG_XEN -#include -#endif - -/* - * Should the kernel map a VDSO page into processes and pass its - * address down to glibc upon exec()? - */ -unsigned int __read_mostly vdso_enabled = 1; - -EXPORT_SYMBOL_GPL(vdso_enabled); - -static int __init vdso_setup(char *s) -{ - vdso_enabled = simple_strtoul(s, NULL, 0); - - return 1; -} - -__setup("vdso=", vdso_setup); - extern asmlinkage void sysenter_entry(void); void enable_sep_cpu(void) { -#ifndef CONFIG_X86_NO_TSS int cpu = get_cpu(); struct tss_struct *tss = &per_cpu(init_tss, cpu); @@ -65,7 +37,6 @@ void enable_sep_cpu(void) wrmsr(MSR_IA32_SYSENTER_ESP, tss->esp1, 0); wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0); put_cpu(); -#endif } /* @@ -74,137 +45,23 @@ void enable_sep_cpu(void) */ extern const char vsyscall_int80_start, vsyscall_int80_end; extern const char vsyscall_sysenter_start, vsyscall_sysenter_end; -static void *syscall_page; int __init sysenter_setup(void) { - syscall_page = (void *)get_zeroed_page(GFP_ATOMIC); - -#ifdef CONFIG_XEN - if (boot_cpu_has(X86_FEATURE_SEP)) { - struct callback_register sysenter = { - .type = CALLBACKTYPE_sysenter, - .address = { __KERNEL_CS, (unsigned long)sysenter_entry }, - }; + void *page = (void *)get_zeroed_page(GFP_ATOMIC); - if (HYPERVISOR_callback_op(CALLBACKOP_register, &sysenter) < 0) - clear_bit(X86_FEATURE_SEP, boot_cpu_data.x86_capability); - } -#endif - -#ifdef CONFIG_COMPAT_VDSO - __set_fixmap(FIX_VDSO, __pa(syscall_page), PAGE_READONLY); - printk("Compat vDSO mapped to %08lx.\n", __fix_to_virt(FIX_VDSO)); -#else - /* - * In the non-compat case the ELF coredumping code needs the fixmap: - */ -#ifdef CONFIG_XEN - __set_fixmap(FIX_VDSO, virt_to_machine(syscall_page), PAGE_KERNEL_RO); -#else - __set_fixmap(FIX_VDSO, __pa(syscall_page), PAGE_KERNEL_RO); -#endif -#endif + __set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_READONLY_EXEC); if (!boot_cpu_has(X86_FEATURE_SEP)) { - memcpy(syscall_page, + memcpy(page, &vsyscall_int80_start, &vsyscall_int80_end - &vsyscall_int80_start); return 0; } - memcpy(syscall_page, + memcpy(page, &vsyscall_sysenter_start, &vsyscall_sysenter_end - &vsyscall_sysenter_start); return 0; } - -static struct page *syscall_nopage(struct vm_area_struct *vma, - unsigned long adr, int *type) -{ - struct page *p = virt_to_page(adr - vma->vm_start + syscall_page); - get_page(p); - return p; -} - -/* Prevent VMA merging */ -static void syscall_vma_close(struct vm_area_struct *vma) -{ -} - -static struct vm_operations_struct syscall_vm_ops = { - .close = syscall_vma_close, - .nopage = syscall_nopage, -}; - -/* Defined in vsyscall-sysenter.S */ -extern void SYSENTER_RETURN; - -/* Setup a VMA at program startup for the vsyscall page */ -int arch_setup_additional_pages(struct linux_binprm *bprm, int exstack, - unsigned long start_code, unsigned long interp_map_address) -{ - struct vm_area_struct *vma; - struct mm_struct *mm = current->mm; - unsigned long addr; - int ret; - - down_write(&mm->mmap_sem); - addr = get_unmapped_area_prot(NULL, 0, PAGE_SIZE, 0, 0, 1); - if (IS_ERR_VALUE(addr)) { - ret = addr; - goto up_fail; - } - - vma = kmem_cache_zalloc(vm_area_cachep, SLAB_KERNEL); - if (!vma) { - ret = -ENOMEM; - goto up_fail; - } - - vma->vm_start = addr; - vma->vm_end = addr + PAGE_SIZE; - /* MAYWRITE to allow gdb to COW and set breakpoints */ - vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYWRITE; - vma->vm_flags |= mm->def_flags; - vma->vm_page_prot = protection_map[vma->vm_flags & 7]; - vma->vm_ops = &syscall_vm_ops; - vma->vm_mm = mm; - - ret = insert_vm_struct(mm, vma); - if (unlikely(ret)) { - kmem_cache_free(vm_area_cachep, vma); - goto up_fail; - } - - current->mm->context.vdso = (void *)addr; - current_thread_info()->sysenter_return = - (void *)VDSO_SYM(&SYSENTER_RETURN); - vx_vmpages_inc(mm); -up_fail: - up_write(&mm->mmap_sem); - return ret; -} - -const char *arch_vma_name(struct vm_area_struct *vma) -{ - if (vma->vm_mm && vma->vm_start == (long)vma->vm_mm->context.vdso) - return "[vdso]"; - return NULL; -} - -struct vm_area_struct *get_gate_vma(struct task_struct *tsk) -{ - return NULL; -} - -int in_gate_area(struct task_struct *task, unsigned long addr) -{ - return 0; -} - -int in_gate_area_no_task(unsigned long addr) -{ - return 0; -}