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Subject[PATCH v1 11/30] powerpc/vdso: Provide vdso_remap()
Date
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 | 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 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 9b2c91a963a6..971764d5b85b 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,
};

/*
--
2.25.0
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