x86/vdso: Replace calculate_addr in map_vdso() with addr
That will allow to specify address where to map vDSO blob.
For the randomized vDSO mappings introduce map_vdso_randomized()
which will simplify calls to map_vdso.
Signed-off-by: Dmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: Andy Lutomirski <luto@kernel.org>
Cc: 0x7f454c46@gmail.com
Cc: oleg@redhat.com
Cc: linux-mm@kvack.org
Cc: gorcunov@openvz.org
Cc: xemul@virtuozzo.com
Link: http://lkml.kernel.org/r/20160905133308.28234-3-dsafonov@virtuozzo.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index 3bab6ba..5bcb25a 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -176,11 +176,16 @@
return VM_FAULT_SIGBUS;
}
-static int map_vdso(const struct vdso_image *image, bool calculate_addr)
+/*
+ * Add vdso and vvar mappings to current process.
+ * @image - blob to map
+ * @addr - request a specific address (zero to map at free addr)
+ */
+static int map_vdso(const struct vdso_image *image, unsigned long addr)
{
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
- unsigned long addr, text_start;
+ unsigned long text_start;
int ret = 0;
static const struct vm_special_mapping vdso_mapping = {
@@ -193,13 +198,6 @@
.fault = vvar_fault,
};
- if (calculate_addr) {
- addr = vdso_addr(current->mm->start_stack,
- image->size - image->sym_vvar_start);
- } else {
- addr = 0;
- }
-
if (down_write_killable(&mm->mmap_sem))
return -EINTR;
@@ -251,13 +249,20 @@
return ret;
}
+static int map_vdso_randomized(const struct vdso_image *image)
+{
+ unsigned long addr = vdso_addr(current->mm->start_stack,
+ image->size - image->sym_vvar_start);
+ return map_vdso(image, addr);
+}
+
#if defined(CONFIG_X86_32) || defined(CONFIG_IA32_EMULATION)
static int load_vdso32(void)
{
if (vdso32_enabled != 1) /* Other values all mean "disabled" */
return 0;
- return map_vdso(&vdso_image_32, false);
+ return map_vdso(&vdso_image_32, 0);
}
#endif
@@ -267,7 +272,7 @@
if (!vdso64_enabled)
return 0;
- return map_vdso(&vdso_image_64, true);
+ return map_vdso_randomized(&vdso_image_64);
}
#ifdef CONFIG_COMPAT
@@ -278,8 +283,7 @@
if (test_thread_flag(TIF_X32)) {
if (!vdso64_enabled)
return 0;
-
- return map_vdso(&vdso_image_x32, true);
+ return map_vdso_randomized(&vdso_image_x32);
}
#endif
#ifdef CONFIG_IA32_EMULATION
