Hi Abdul,
On Tue 07-11-17 11:28:54, Michal Hocko wrote:
> On Tue 07-11-17 15:20:29, Abdul Haleem wrote:
> > Hi,
> >
> > Today's next kernel fails to boot on Power 7 Machine with below errors
> > in boot log messages.
> >
> > 'Uhuuh, elf segement at 0000000010040000 requested but the memory is
> > mapped already'
> >
> > It was introduced with commit:
> >
> > 0692229e : fs/binfmt_elf.c: drop MAP_FIXED usage from elf_map
>
> Weird. Clashes shouldn't really happen. Maybe power is doing something
> different from other platforms. Could you apply the following debugging
> patch to see what is going on there?
Did you have chance to test with this debugging patch, please?
> ---
> diff --git a/fs/binfmt_elf.c b/fs/binfmt_elf.c
> index 0abc30d681ae..f098aaf60039 100644
> --- a/fs/binfmt_elf.c
> +++ b/fs/binfmt_elf.c
> @@ -361,8 +361,28 @@ static unsigned long elf_vm_mmap(struct file *filep,
> unsigned long addr,
> return map_addr;
>
> if ((type & MAP_FIXED) && map_addr != addr) {
> - pr_info("Uhuuh, elf segement at %p requested but the memory is
> mapped already\n",
> - (void*)addr);
> + struct mm_struct *mm = current->mm;
> + struct vm_area_struct *vma;
> + pr_info("Uhuuh, elf segement at %p requested but the memory is
> mapped already, got %p\n",
> + (void*)addr, (void*)map_addr);
> + down_read(&mm->mmap_sem);
> + vma = find_vma(mm, addr);
> + if (vma) {
> + const char *name;
> + pr_info("Clashing vma [%lx, %lx] flags:%lx",
> vma->vm_start, vma->vm_end, vma->vm_flags);
> + name = arch_vma_name(vma);
> + if (!name) {
> + if (vma->vm_start <= mm->brk &&
> + vma->vm_end >= mm->start_brk)
> + name = "[heap]";
> + else if (vma->vm_start <=
> vma->vm_mm->start_stack &&
> + vma->vm_end >=
> vma->vm_mm->start_stack)
> + name = "[stack]";
> + }
> + pr_cont(" name:%s\n", name);
> + } else
> + pr_info("Uhm, no clashing VMA\n");
> + up_read(&mm->mmap_sem);
> return -EAGAIN;
> }
>
>
> --
> Michal Hocko
> SUSE Labs
--
Michal Hocko
SUSE Labs
