Messages in this thread Patch in this message | | | From | Christophe Leroy <> | Subject | [PATCH v1 6/9] powerpc/vdso: Provide vdso_remap() | Date | Tue, 25 Aug 2020 13:54:04 +0000 (UTC) |
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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 <christophe.leroy@csgroup.eu> --- arch/powerpc/include/asm/mm-arch-hooks.h | 25 --------------------- arch/powerpc/kernel/vdso.c | 28 ++++++++++++++++++++++++ 2 files changed, 28 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 dce274be824a..000000000000 --- 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 <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 */ diff --git a/arch/powerpc/kernel/vdso.c b/arch/powerpc/kernel/vdso.c index 4ccfc0dc96b5..b9270923452e 100644 --- a/arch/powerpc/kernel/vdso.c +++ b/arch/powerpc/kernel/vdso.c @@ -114,13 +114,41 @@ struct lib64_elfinfo unsigned long text; }; +static int vdso_mremap(unsigned long vdso_pages, + const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + unsigned long new_size = new_vma->vm_end - new_vma->vm_start; + unsigned long vdso_size = (vdso_pages + 1) << PAGE_SHIFT; + + if (new_size != vdso_size) + return -EINVAL; + + current->mm->context.vdso_base = (unsigned long)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(vdso32_pages, sm, new_vma); +} + +static int vdso64_mremap(const struct vm_special_mapping *sm, + struct vm_area_struct *new_vma) +{ + return vdso_mremap(vdso64_pages, sm, new_vma); +} 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, }; /* -- 2.25.0
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