---

yaml
---
r: 73
b: refs/heads/master
c: 1e01441
h: refs/heads/master
i:
  71: 7d40d27
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 35faa71484287fc150b8498cd5acae59ad17a356
+refs/heads/master: 1e01441051dda3bb01c455b6e20bce6d00563d82

trunk/arch/x86_64/ia32/ia32_binfmt.c

@@ -312,6 +312,10 @@ MODULE_AUTHOR("Eric Youngdale, Andi Kleen");
 
 static void elf32_init(struct pt_regs *);
 
+#define ARCH_HAS_SETUP_ADDITIONAL_PAGES 1
+#define arch_setup_additional_pages syscall32_setup_pages
+extern int syscall32_setup_pages(struct linux_binprm *, int exstack);
+
 #include "../../../fs/binfmt_elf.c" 
 
 static void elf32_init(struct pt_regs *regs)

trunk/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>
@@ -30,59 +31,64 @@ extern int sysctl_vsyscall32;
 char *syscall32_page; 
 static int use_sysenter = -1;
 
-/*
- * Map the 32bit vsyscall page on demand.
- *
- * 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)
-{ 
-	pgd_t *pgd;
-	pud_t *pud;
-	pte_t *pte;
-	pmd_t *pmd;
-	int err = -ENOMEM;
-
-	spin_lock(&mm->page_table_lock); 
- 	pgd = pgd_offset(mm, address);
- 	pud = pud_alloc(mm, pgd, address);
- 	if (pud) {
- 		pmd = pmd_alloc(mm, pud, 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_VSYSCALL32));
- 			}
- 			/* Flush only the local CPU. Other CPUs taking a fault
- 			   will just end up here again
-			   This probably not needed and just paranoia. */
- 			__flush_tlb_one(address);
- 			err = 0;
-		}
-	}
-	spin_unlock(&mm->page_table_lock);
-	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;
 }
 
-int map_syscall32(struct mm_struct *mm, unsigned long address)
+/* Prevent VMA merging */
+static void syscall32_vma_close(struct vm_area_struct *vma)
 {
-	int err;
-	down_read(&mm->mmap_sem);
-	err = __map_syscall32(mm, address);
-	up_read(&mm->mmap_sem);
-	return err;
+}
+
+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)
 { 
 	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);

trunk/arch/x86_64/mm/fault.c

@@ -458,17 +458,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
 	up_read(&mm->mmap_sem);
 
 bad_area_nosemaphore:
-
-#ifdef CONFIG_IA32_EMULATION
-	/* 32bit vsyscall. map on demand. */
-	if (test_thread_flag(TIF_IA32) &&
-	    address >= VSYSCALL32_BASE && address < VSYSCALL32_END) {
-		if (map_syscall32(mm, address) < 0)
-			goto out_of_memory2;
-		return;
-	}
-#endif
-
 	/* User mode accesses just cause a SIGSEGV */
 	if (error_code & 4) {
 		if (is_prefetch(regs, address, error_code))
@@ -550,7 +539,6 @@ asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code)
  */
 out_of_memory:
 	up_read(&mm->mmap_sem);
-out_of_memory2:
 	if (current->pid == 1) { 
 		yield();
 		goto again;

trunk/arch/x86_64/mm/init.c

@@ -583,39 +583,30 @@ static __init int x8664_sysctl_init(void)
 __initcall(x8664_sysctl_init);
 #endif
 
-/* Pseudo VMAs to allow ptrace access for the vsyscall pages.  x86-64 has two
-   different ones: one for 32bit and one for 64bit. Use the appropiate
-   for the target task. */
+/* A pseudo VMAs to allow ptrace access for the vsyscall page.   This only
+   covers the 64bit vsyscall page now. 32bit has a real VMA now and does
+   not need special handling anymore. */
 
 static struct vm_area_struct gate_vma = {
 	.vm_start = VSYSCALL_START,
 	.vm_end = VSYSCALL_END,
 	.vm_page_prot = PAGE_READONLY
 };
 
-static struct vm_area_struct gate32_vma = {
-	.vm_start = VSYSCALL32_BASE,
-	.vm_end = VSYSCALL32_END,
-	.vm_page_prot = PAGE_READONLY
-};
-
 struct vm_area_struct *get_gate_vma(struct task_struct *tsk)
 {
 #ifdef CONFIG_IA32_EMULATION
-	if (test_tsk_thread_flag(tsk, TIF_IA32)) {
-		/* lookup code assumes the pages are present. set them up
-		   now */
-		if (__map_syscall32(tsk->mm, VSYSCALL32_BASE) < 0)
-			return NULL;
-		return &gate32_vma;
-	}
+	if (test_tsk_thread_flag(tsk, TIF_IA32))
+		return NULL;
 #endif
 	return &gate_vma;
 }
 
 int in_gate_area(struct task_struct *task, unsigned long addr)
 {
 	struct vm_area_struct *vma = get_gate_vma(task);
+	if (!vma)
+		return 0;
 	return (addr >= vma->vm_start) && (addr < vma->vm_end);
 }
 
@@ -625,6 +616,5 @@ int in_gate_area(struct task_struct *task, unsigned long addr)
  */
 int in_gate_area_no_task(unsigned long addr)
 {
-	return (((addr >= VSYSCALL_START) && (addr < VSYSCALL_END)) ||
-		((addr >= VSYSCALL32_BASE) && (addr < VSYSCALL32_END)));
+	return (addr >= VSYSCALL_START) && (addr < VSYSCALL_END);
 }

trunk/include/asm-x86_64/proto.h

@@ -69,8 +69,6 @@ extern void __die(const char * str, struct pt_regs * regs, long err);
 extern void __show_regs(struct pt_regs * regs);
 extern void show_regs(struct pt_regs * regs);
 
-extern int map_syscall32(struct mm_struct *mm, unsigned long address);
-extern int __map_syscall32(struct mm_struct *mm, unsigned long address);
 extern char *syscall32_page;
 extern void syscall32_cpu_init(void);