From: Laurent Dufour Date: Wed, 24 Jun 2015 23:56:22 +0000 (-0700) Subject: powerpc/mm: tracking vDSO remap X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=83d3f0e90c6c8f833e3da91917c243a916fda69e;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git powerpc/mm: tracking vDSO remap Some processes (CRIU) are moving the vDSO area using the mremap system call. As a consequence the kernel reference to the vDSO base address is no more valid and the signal return frame built once the vDSO has been moved is not pointing to the new sigreturn address. This patch handles vDSO remapping and unmapping. Signed-off-by: Laurent Dufour Reviewed-by: Ingo Molnar Cc: "Kirill A. Shutemov" Cc: Hugh Dickins Cc: Rik van Riel Cc: Mel Gorman Cc: Pavel Emelyanov Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Michael Ellerman Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- diff --git a/arch/powerpc/include/asm/mm-arch-hooks.h b/arch/powerpc/include/asm/mm-arch-hooks.h index 63091a19de9f..f2a2da895897 100644 --- a/arch/powerpc/include/asm/mm-arch-hooks.h +++ b/arch/powerpc/include/asm/mm-arch-hooks.h @@ -12,4 +12,17 @@ #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/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h index 3e5184210d9b..878c27771717 100644 --- a/arch/powerpc/include/asm/mmu_context.h +++ b/arch/powerpc/include/asm/mmu_context.h @@ -8,7 +8,6 @@ #include #include #include -#include #include /* @@ -127,5 +126,27 @@ static inline void enter_lazy_tlb(struct mm_struct *mm, #endif } +static inline void arch_dup_mmap(struct mm_struct *oldmm, + struct mm_struct *mm) +{ +} + +static inline void arch_exit_mmap(struct mm_struct *mm) +{ +} + +static inline void arch_unmap(struct mm_struct *mm, + struct vm_area_struct *vma, + unsigned long start, unsigned long end) +{ + if (start <= mm->context.vdso_base && mm->context.vdso_base < end) + mm->context.vdso_base = 0; +} + +static inline void arch_bprm_mm_init(struct mm_struct *mm, + struct vm_area_struct *vma) +{ +} + #endif /* __KERNEL__ */ #endif /* __ASM_POWERPC_MMU_CONTEXT_H */