Both applied, thanks. Serge E. Hallyn wrote: > Break do_munmap into two pieces, so we can avoid the check > for > TASK_SIZE in destroy_mm(), when we trust the vmas are > proper. > > Really I wonder whether we can pull a lot more out of the > fn used by destroy_mm: is there really a need to be looking > whether we need to split vmas? We always send in one full > vma at a time, so maybe we should just be calling > detach_vmas_to_be_unmapped() and unmap_region() by hand? > > this makes 32-bit tasks on x86-64 with COMPAT_VDSO work again. > It also gets us passed the munmap -EINVAL when restart_64 > restarts a 32-bit image and unloads its own 64-bit vmas. > > (But there is still a > > ckpt[2446] general protection ip:ffffe42f sp:ffc9304c error:0 > > with that case) > > Signed-off-by: Serge E. Hallyn <[email protected]> > --- > checkpoint/memory.c | 18 ------------------ > include/linux/mm.h | 1 + > mm/mmap.c | 38 ++++++++++++++++++++++++++++++++++---- > 3 files changed, 35 insertions(+), 22 deletions(-) > > diff --git a/checkpoint/memory.c b/checkpoint/memory.c > index f907b88..d51f94b 100644 > --- a/checkpoint/memory.c > +++ b/checkpoint/memory.c > @@ -1205,24 +1205,6 @@ static int restore_vma(struct ckpt_ctx *ctx, struct > mm_struct *mm) > return ret; > } > > -static int destroy_mm(struct mm_struct *mm) > -{ > - struct vm_area_struct *vmnext = mm->mmap; > - struct vm_area_struct *vma; > - int ret; > - > - while (vmnext) { > - vma = vmnext; > - vmnext = vmnext->vm_next; > - ret = do_munmap(mm, vma->vm_start, vma->vm_end-vma->vm_start); > - if (ret < 0) { > - pr_warning("c/r: failed do_munmap (%d)\n", ret); > - return ret; > - } > - } > - return 0; > -} > - > static struct mm_struct *do_restore_mm(struct ckpt_ctx *ctx) > { > struct ckpt_hdr_mm *h; > diff --git a/include/linux/mm.h b/include/linux/mm.h > index dc34b87..4485296 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -1168,6 +1168,7 @@ out: > } > > extern int do_munmap(struct mm_struct *, unsigned long, size_t); > +extern int destroy_mm(struct mm_struct *); > > extern unsigned long do_brk(unsigned long, unsigned long); > > diff --git a/mm/mmap.c b/mm/mmap.c > index 0b2319f..15afae6 100644 > --- a/mm/mmap.c > +++ b/mm/mmap.c > @@ -1890,14 +1890,11 @@ int split_vma(struct mm_struct * mm, struct > vm_area_struct * vma, > * work. This now handles partial unmappings. > * Jeremy Fitzhardinge <[email protected]> > */ > -int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) > +int do_munmap_nocheck(struct mm_struct *mm, unsigned long start, size_t len) > { > unsigned long end; > struct vm_area_struct *vma, *prev, *last; > > - if ((start & ~PAGE_MASK) || start > TASK_SIZE || len > TASK_SIZE-start) > - return -EINVAL; > - > if ((len = PAGE_ALIGN(len)) == 0) > return -EINVAL; > > @@ -1961,8 +1958,41 @@ int do_munmap(struct mm_struct *mm, unsigned long > start, size_t len) > return 0; > } > > +int do_munmap(struct mm_struct *mm, unsigned long start, size_t len) > +{ > + unsigned long end; > + struct vm_area_struct *vma, *prev, *last; > + > + if ((start & ~PAGE_MASK) || start > TASK_SIZE || len > TASK_SIZE-start) > + return -EINVAL; > + > + return do_munmap_nocheck(mm, start, len); > +} > + > EXPORT_SYMBOL(do_munmap); > > +/* > + * called with mm->mmap-sem held > + * only called from checkpoint/memory.c:restore_mm() > + */ > +int destroy_mm(struct mm_struct *mm) { > + struct vm_area_struct *vmnext = mm->mmap; > + struct vm_area_struct *vma; > + int ret; > + > + while (vmnext) { > + vma = vmnext; > + vmnext = vmnext->vm_next; > + ret = do_munmap_nocheck(mm, vma->vm_start, > + vma->vm_end-vma->vm_start); > + if (ret < 0) { > + pr_warning("%s: failed munmap (%d)\n", __func__, ret); > + return ret; > + } > + } > + return 0; > +} > + > SYSCALL_DEFINE2(munmap, unsigned long, addr, size_t, len) > { > int ret; _______________________________________________ Containers mailing list [email protected] https://lists.linux-foundation.org/mailman/listinfo/containers
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