vserver 2.0 rc7

[linux-2.6.git] / arch / x86_64 / ia32 / syscall32.c

diff --git a/arch/x86_64/ia32/syscall32.c b/arch/x86_64/ia32/syscall32.c
index 64b7a59..01d8db1 100644 (file)
--- a/arch/x86_64/ia32/syscall32.c
+++ b/arch/x86_64/ia32/syscall32.c
@@ -9,6 +9,7 @@
 #include <linux/gfp.h>
 #include <linux/init.h>
 #include <linux/stringify.h>
+#include <linux/security.h>
 #include <asm/proto.h>
 #include <asm/tlbflush.h>
 #include <asm/ia32_unistd.h>
@@ -28,34 +29,59 @@ extern unsigned char syscall32_sysenter[], syscall32_sysenter_end[];
 extern int sysctl_vsyscall32;
 
 char *syscall32_page; 
-static int use_sysenter __initdata = -1;
+static int use_sysenter = -1;
 
-/* RED-PEN: This knows too much about high level VM */ 
-/* Alternative would be to generate a vma with appropriate backing options
-   and let it be handled by generic VM */ 
-int map_syscall32(struct mm_struct *mm, unsigned long address) 
-{ 
-       pte_t *pte;
-       pmd_t *pmd;
-       int err = 0;
-
-       down_read(&mm->mmap_sem);
-       spin_lock(&mm->page_table_lock); 
-       pmd = pmd_alloc(mm, pgd_offset(mm, address), address); 
-       if (pmd && (pte = pte_alloc_map(mm, pmd, address)) != NULL) { 
-               if (pte_none(*pte)) { 
-                       set_pte(pte, 
-                               mk_pte(virt_to_page(syscall32_page), 
-                                      PAGE_KERNEL_VSYSCALL)); 
-               }
-               /* Flush only the local CPU. Other CPUs taking a fault
-                  will just end up here again */
-               __flush_tlb_one(address); 
-       } else
-               err = -ENOMEM; 
-       spin_unlock(&mm->page_table_lock);
-       up_read(&mm->mmap_sem);
-       return err;
+static struct page *
+syscall32_nopage(struct vm_area_struct *vma, unsigned long adr, int *type)
+{
+       struct page *p = virt_to_page(adr - vma->vm_start + syscall32_page);
+       get_page(p);
+       return p;
+}
+
+/* Prevent VMA merging */
+static void syscall32_vma_close(struct vm_area_struct *vma)
+{
+}
+
+static struct vm_operations_struct syscall32_vm_ops = {
+       .close = syscall32_vma_close,
+       .nopage = syscall32_nopage,
+};
+
+struct linux_binprm;
+
+/* Setup a VMA at program startup for the vsyscall page */
+int syscall32_setup_pages(struct linux_binprm *bprm, int exstack)
+{
+       int npages = (VSYSCALL32_END - VSYSCALL32_BASE) >> PAGE_SHIFT;
+       struct vm_area_struct *vma;
+       struct mm_struct *mm = current->mm;
+
+       vma = kmem_cache_alloc(vm_area_cachep, SLAB_KERNEL);
+       if (!vma)
+               return -ENOMEM;
+       if (security_vm_enough_memory(npages)) {
+               kmem_cache_free(vm_area_cachep, vma);
+               return -ENOMEM;
+       }
+
+       memset(vma, 0, sizeof(struct vm_area_struct));
+       /* Could randomize here */
+       vma->vm_start = VSYSCALL32_BASE;
+       vma->vm_end = VSYSCALL32_END;
+       /* MAYWRITE to allow gdb to COW and set breakpoints */
+       vma->vm_flags = VM_READ|VM_EXEC|VM_MAYREAD|VM_MAYEXEC|VM_MAYEXEC|VM_MAYWRITE;
+       vma->vm_flags |= mm->def_flags;
+       vma->vm_page_prot = protection_map[vma->vm_flags & 7];
+       vma->vm_ops = &syscall32_vm_ops;
+       vma->vm_mm = mm;
+
+       down_write(&mm->mmap_sem);
+       insert_vm_struct(mm, vma);
+       mm->total_vm += npages;
+       up_write(&mm->mmap_sem);
+       return 0;
 }
 
 static int __init init_syscall32(void)
@@ -63,7 +89,6 @@ static int __init init_syscall32(void)
        syscall32_page = (void *)get_zeroed_page(GFP_KERNEL); 
        if (!syscall32_page) 
                panic("Cannot allocate syscall32 page"); 
-       SetPageReserved(virt_to_page(syscall32_page));
        if (use_sysenter > 0) {
                memcpy(syscall32_page, syscall32_sysenter,
                       syscall32_sysenter_end - syscall32_sysenter);
@@ -76,16 +101,17 @@ static int __init init_syscall32(void)
        
 __initcall(init_syscall32); 
 
-void __init syscall32_cpu_init(void)
+/* May not be __init: called during resume */
+void syscall32_cpu_init(void)
 {
        if (use_sysenter < 0)
                use_sysenter = (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL);
 
        /* Load these always in case some future AMD CPU supports
           SYSENTER from compat mode too. */
-       wrmsr(MSR_IA32_SYSENTER_CS, __KERNEL_CS, 0);
-       wrmsr(MSR_IA32_SYSENTER_ESP, 0, 0);
-       wrmsrl(MSR_IA32_SYSENTER_EIP, ia32_sysenter_target);
+       checking_wrmsrl(MSR_IA32_SYSENTER_CS, (u64)__KERNEL_CS);
+       checking_wrmsrl(MSR_IA32_SYSENTER_ESP, 0ULL);
+       checking_wrmsrl(MSR_IA32_SYSENTER_EIP, (u64)ia32_sysenter_target);
 
        wrmsrl(MSR_CSTAR, ia32_cstar_target);
 }