Fedora kernel-2.6.17-1.2142_FC4 patched with stable patch-2.6.17.4-vs2.0.2-rc26.diff

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

diff --git a/arch/i386/kernel/sysenter.c b/arch/i386/kernel/sysenter.c
index 960d8bd..ec4959f 100644 (file)
--- a/arch/i386/kernel/sysenter.c
+++ b/arch/i386/kernel/sysenter.c
@@ -13,7 +13,9 @@
 #include <linux/gfp.h>
 #include <linux/string.h>
 #include <linux/elf.h>
+#include <linux/mman.h>
 
+#include <asm/a.out.h>
 #include <asm/cpufeature.h>
 #include <asm/msr.h>
 #include <asm/pgtable.h>
@@ -21,11 +23,16 @@
 
 extern asmlinkage void sysenter_entry(void);
 
-void enable_sep_cpu(void *info)
+void enable_sep_cpu(void)
 {
        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);
@@ -41,11 +48,13 @@ void enable_sep_cpu(void *info)
 extern const char vsyscall_int80_start, vsyscall_int80_end;
 extern const char vsyscall_sysenter_start, vsyscall_sysenter_end;
 
-static int __init sysenter_setup(void)
+static struct page *sysenter_pages[2];
+
+int __init sysenter_setup(void)
 {
        void *page = (void *)get_zeroed_page(GFP_ATOMIC);
 
-       __set_fixmap(FIX_VSYSCALL, __pa(page), PAGE_READONLY_EXEC);
+       sysenter_pages[0] = virt_to_page(page);
 
        if (!boot_cpu_has(X86_FEATURE_SEP)) {
                memcpy(page,
@@ -58,8 +67,80 @@ static int __init sysenter_setup(void)
               &vsyscall_sysenter_start,
               &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;
+
+/*
+ * This is called from binfmt_elf, we create the special vma for the
+ * vDSO and insert it into the mm struct tree.
+ */
+int arch_setup_additional_pages(struct linux_binprm *bprm,
+       int executable_stack, unsigned long start_code,
+       unsigned long interp_map_address)
+{
+       struct thread_info *ti = current_thread_info();
+       unsigned long addr = 0, len;
+       unsigned flags = MAP_PRIVATE;
+       int err;
+
+       current->mm->context.vdso = NULL;
+       if (unlikely(!vdso_enabled) || unlikely(!sysenter_pages[0]))
+               return 0;
+
+       /*
+        * Map the vDSO (it will be randomized):
+        */
+       down_write(&current->mm->mmap_sem);
+       len = PAGE_SIZE > ELF_EXEC_PAGESIZE ? PAGE_SIZE : ELF_EXEC_PAGESIZE;
+       if (0==exec_shield) { /* off; %cs limit off */
+               addr = STACK_TOP;  /* minimal interference with anybody */
+               flags = MAP_PRIVATE | MAP_FIXED;
+       }
+       else if ((3<<2) & exec_shield) { /* vdso just below .text */
+               addr = (((2<<2) & exec_shield) && interp_map_address) ?
+                       interp_map_address : start_code;
+               /* 1MB for vm86; 64K for vm86 himem */
+               if ((0x110000 + len) <= addr) {
+                       addr = (PAGE_MASK & addr) - len;
+               }
+               else { /* start_code is too low */
+                       addr = 0;
+               }
+       }
+       addr = get_unmapped_area_prot(NULL, addr, len, 0,
+                                     flags, PROT_READ | PROT_EXEC);
+       if (unlikely(addr & ~PAGE_MASK)) {
+               up_write(&current->mm->mmap_sem);
+               return addr;
+       }
+       err = install_special_mapping(current->mm, addr, len,
+                                     VM_DONTEXPAND | VM_READ | VM_EXEC |
+                                     VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
+                                     PAGE_READONLY_EXEC,
+                                     sysenter_pages);
+       if (likely(err == 0)) {
+               current->mm->context.vdso = (void *)addr;
+               ti->sysenter_return = &SYSENTER_RETURN_OFFSET + addr;
+       }
+       up_write(&current->mm->mmap_sem);
+       return err;
+}
+
+int in_gate_area_no_task(unsigned long addr)
+{
+       return 0;
+}
+
+int in_gate_area(struct task_struct *task, unsigned long addr)
+{
+       return 0;
+}
+
+struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
+{
+       return NULL;
+}