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Commit 576ebfef authored by Dmitry Safonov's avatar Dmitry Safonov Committed by Thomas Gleixner
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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: default avatarDmitry Safonov <dsafonov@virtuozzo.com>
Acked-by: default avatarAndy 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: default avatarThomas Gleixner <tglx@linutronix.de>
parent e38447ee

arch/x86/entry/vdso/vma.c

+17 −13
Original line number Diff line number Diff line
@@ -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