X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=arch%2Fi386%2Fkernel%2Fsysenter.c.orig;fp=arch%2Fi386%2Fkernel%2Fsysenter.c.orig;h=89845cabc06b6fa87f0e0b6b7c582447353702e1;hb=3c0f84cf4c70d1bcbffe135dade50fad833f0cf4;hp=0000000000000000000000000000000000000000;hpb=c469b50b11a8eaa1dc314687c2b6030c8fdea5b7;p=linux-2.6.git

diff --git a/arch/i386/kernel/sysenter.c.orig b/arch/i386/kernel/sysenter.c.orig
new file mode 100644
index 000000000..89845cabc
--- /dev/null
+++ b/arch/i386/kernel/sysenter.c.orig
@@ -0,0 +1,209 @@
+/*
+ * 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.
+ */
+
+#include <linux/init.h>
+#include <linux/smp.h>
+#include <linux/thread_info.h>
+#include <linux/sched.h>
+#include <linux/gfp.h>
+#include <linux/string.h>
+#include <linux/elf.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/module.h>
+
+#include <asm/cpufeature.h>
+#include <asm/msr.h>
+#include <asm/pgtable.h>
+#include <asm/unistd.h>
+
+#ifdef CONFIG_XEN
+#include <xen/interface/callback.h>
+#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);
+
+	if (!boot_cpu_has(X86_FEATURE_SEP)) {
+		put_cpu();
+		return;
+	}
+
+	tss->ss1 = __KERNEL_CS;
+	tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
+	wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
+	wrmsr(MSR_IA32_SYSENTER_ESP, tss->esp1, 0);
+	wrmsr(MSR_IA32_SYSENTER_EIP, (unsigned long) sysenter_entry, 0);
+	put_cpu();	
+#endif
+}
+
+/*
+ * These symbols are defined by vsyscall.o to mark the bounds
+ * of the ELF DSO images included therein.
+ */
+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 },
+		};
+
+		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
+
+	if (!boot_cpu_has(X86_FEATURE_SEP)) {
+		memcpy(syscall_page,
+		       &vsyscall_int80_start,
+		       &vsyscall_int80_end - &vsyscall_int80_start);
+		return 0;
+	}
+
+	memcpy(syscall_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);
+	mm->total_vm++;
+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;
+}