This commit was manufactured by cvs2svn to create tag

[linux-2.6.git] / arch / i386 / kernel / sysenter.c

diff --git a/arch/i386/kernel/sysenter.c b/arch/i386/kernel/sysenter.c
index c9194e3..8047133 100644 (file)
--- a/arch/i386/kernel/sysenter.c
+++ b/arch/i386/kernel/sysenter.c
@@ -13,18 +13,24 @@
 #include <linux/gfp.h>
 #include <linux/string.h>
 #include <linux/elf.h>
+#include <linux/mman.h>
 
 #include <asm/cpufeature.h>
 #include <asm/msr.h>
 #include <asm/pgtable.h>
 #include <asm/unistd.h>
+#include <linux/highmem.h>
 
 extern asmlinkage void sysenter_entry(void);
 
 void enable_sep_cpu(void *info)
 {
        int cpu = get_cpu();
+#ifdef CONFIG_X86_HIGH_ENTRY
+       struct tss_struct *tss = (struct tss_struct *) __fix_to_virt(FIX_TSS_0) + cpu;
+#else
        struct tss_struct *tss = init_tss + cpu;
+#endif
 
        tss->ss1 = __KERNEL_CS;
        tss->esp1 = sizeof(struct tss_struct) + (unsigned long) tss;
@@ -41,11 +47,14 @@ void enable_sep_cpu(void *info)
 extern const char vsyscall_int80_start, vsyscall_int80_end;
 extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
 
+struct page *sysenter_page;
+
 static int __init sysenter_setup(void)
 {
        unsigned long page = get_zeroed_page(GFP_ATOMIC);
 
-       __set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_READONLY);
+       __set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_KERNEL_RO);
+       sysenter_page = virt_to_page(page);
 
        if (!boot_cpu_has(X86_FEATURE_SEP)) {
                memcpy((void *) page,
@@ -59,7 +68,51 @@ static int __init sysenter_setup(void)
               &vsyscall_sysenter_end - &vsyscall_sysenter_start);
 
        on_each_cpu(enable_sep_cpu, NULL, 1, 1);
+
        return 0;
 }
 
 __initcall(sysenter_setup);
+
+extern void SYSENTER_RETURN_OFFSET;
+
+unsigned int vdso_enabled = 1;
+
+void map_vsyscall(void)
+{
+       struct thread_info *ti = current_thread_info();
+       struct vm_area_struct *vma;
+       unsigned long addr;
+
+       if (unlikely(!vdso_enabled)) {
+               current->mm->context.vdso = NULL;
+               return;
+       }
+
+       /*
+        * Map the vDSO (it will be randomized):
+        */
+       down_write(&current->mm->mmap_sem);
+       addr = do_mmap(NULL, 0, 4096, PROT_READ | PROT_EXEC, MAP_PRIVATE, 0);
+       current->mm->context.vdso = (void *)addr;
+       ti->sysenter_return = (void *)addr + (long)&SYSENTER_RETURN_OFFSET;
+       if (addr != -1) {
+               vma = find_vma(current->mm, addr);
+               if (vma) {
+                       pgprot_val(vma->vm_page_prot) &= ~_PAGE_RW;
+                       get_page(sysenter_page);
+                       install_page(current->mm, vma, addr,
+                                       sysenter_page, vma->vm_page_prot);
+                       
+               }
+       }
+       up_write(&current->mm->mmap_sem);
+}
+
+static int __init vdso_setup(char *str)
+{
+        vdso_enabled = simple_strtoul(str, NULL, 0);
+        return 1;
+}
+__setup("vdso=", vdso_setup);
+