* Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx> wrote:
> 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 <ldufour@xxxxxxxxxxxxxxxxxx>
> ---
> arch/powerpc/include/asm/mmu_context.h | 36 +++++++++++++++++++++++++++++++++-
> 1 file changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/arch/powerpc/include/asm/mmu_context.h b/arch/powerpc/include/asm/mmu_context.h
> index 73382eba02dc..be5dca3f7826 100644
> --- a/arch/powerpc/include/asm/mmu_context.h
> +++ b/arch/powerpc/include/asm/mmu_context.h
> @@ -8,7 +8,6 @@
> #include <linux/spinlock.h>
> #include <asm/mmu.h>
> #include <asm/cputable.h>
> -#include <asm-generic/mm_hooks.h>
> #include <asm/cputhreads.h>
>
> /*
> @@ -109,5 +108,40 @@ 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)
> +{
> +}
> +
> +#define __HAVE_ARCH_REMAP
> +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 don't allow moving multiple vma so we can limit the check
> + * to old_start == vdso_base.
s/mremap don't allow moving multiple vma
mremap() doesn't allow moving multiple vmas
right?
Thanks,
Ingo
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