Commit 526a9c4a authored by Christophe Leroy's avatar Christophe Leroy Committed by Michael Ellerman
Browse files

powerpc/vdso: Provide vdso_remap() 



Provide vdso_remap() through _install_special_mapping() and
drop arch_remap().

This adds a test of the size and returns -EINVAL if the size
is not correct.

Signed-off-by: default avatarChristophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/373c66f768fa9cc8890f3b55462209a98c522326.1601197618.git.christophe.leroy@csgroup.eu
parent c1bab643

arch/powerpc/include/asm/mm-arch-hooks.h

deleted100644 → 0
+0 −25
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0-only */

/*

 * Architecture specific mm hooks

 *

 * Copyright (C) 2015, IBM Corporation

 * Author: Laurent Dufour <ldufour@linux.vnet.ibm.com>

 */



#ifndef _ASM_POWERPC_MM_ARCH_HOOKS_H

#define _ASM_POWERPC_MM_ARCH_HOOKS_H



static inline void arch_remap(struct mm_struct *mm,

			      unsigned long old_start, unsigned long old_end,

			      unsigned long new_start, unsigned long new_end)

{

	/*

	 * mremap() doesn't allow moving multiple vmas so we can limit the

	 * check to old_start == vdso_base.

	 */

	if (old_start == mm->context.vdso_base)

		mm->context.vdso_base = new_start;

}

#define arch_remap arch_remap



#endif /* _ASM_POWERPC_MM_ARCH_HOOKS_H */

arch/powerpc/kernel/vdso.c

+24 −0
Original line number Diff line number Diff line
@@ -115,13 +115,37 @@ struct lib64_elfinfo 
	unsigned long	text;

};



static int vdso_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma,

		       unsigned long text_size)

{

	unsigned long new_size = new_vma->vm_end - new_vma->vm_start;



	if (new_size != text_size + PAGE_SIZE)

		return -EINVAL;



	current->mm->context.vdso_base = new_vma->vm_start;



	return 0;

}



static int vdso32_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)

{

	return vdso_mremap(sm, new_vma, &vdso32_end - &vdso32_start);

}



static int vdso64_mremap(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma)

{

	return vdso_mremap(sm, new_vma, &vdso64_end - &vdso64_start);

}



static struct vm_special_mapping vdso32_spec __ro_after_init = {

	.name = "[vdso]",

	.mremap = vdso32_mremap,

};



static struct vm_special_mapping vdso64_spec __ro_after_init = {

	.name = "[vdso]",

	.mremap = vdso64_mremap,

};



/*