On 25/03/2015 13:11, Ingo Molnar wrote: > > * Laurent Dufour <lduf...@linux.vnet.ibm.com> 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 <lduf...@linux.vnet.ibm.com> >> --- >> 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?
Sure you're right. I'll provide a v3 fixing that comment. Thanks, Laurent. ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. Take a look and join the conversation now. http://goparallel.sourceforge.net/ _______________________________________________ User-mode-linux-user mailing list User-mode-linux-user@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/user-mode-linux-user