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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>
This commit is contained in:
Dmitry Safonov 2016-09-05 16:33:04 +03:00 committed by Thomas Gleixner
parent e38447ee1f
commit 576ebfefd3
1 changed files with 17 additions and 13 deletions
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30
arch/x86/entry/vdso/vma.c
View File

@ -176,11 +176,16 @@ static int vvar_fault(const struct vm_special_mapping *sm,
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 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
.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 @@ static int map_vdso(const struct vdso_image *image, bool calculate_addr)
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 @@ int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
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 @@ int compat_arch_setup_additional_pages(struct linux_binprm *bprm,
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