From 526a9c4a7234cccf6d900c6e82d79356f974cbfd Mon Sep 17 00:00:00 2001 From: Christophe Leroy Date: Sun, 27 Sep 2020 09:16:28 +0000 Subject: [PATCH] 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: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/373c66f768fa9cc8890f3b55462209a98c522326.1601197618.git.christophe.leroy@csgroup.eu --- arch/powerpc/include/asm/mm-arch-hooks.h | 25 ------------------------ arch/powerpc/kernel/vdso.c | 24 +++++++++++++++++++++++ 2 files changed, 24 insertions(+), 25 deletions(-) delete mode 100644 arch/powerpc/include/asm/mm-arch-hooks.h diff --git a/arch/powerpc/include/asm/mm-arch-hooks.h b/arch/powerpc/include/asm/mm-arch-hooks.h deleted file mode 100644 index dce274be824a9..0000000000000 --- a/arch/powerpc/include/asm/mm-arch-hooks.h +++ /dev/null @@ -1,25 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-only */ -/* - * Architecture specific mm hooks - * - * Copyright (C) 2015, IBM Corporation - * Author: Laurent Dufour - */ - -#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 */ diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 67fb4c7e504c1..2b975759a04d6 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -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, }; /* -- 2.39.5