Re: [PATCH 1/2] elf: simpler check for -EEXIST

From: Alexey Dobriyan
Date: Fri Mar 15 2019 - 12:05:24 EST


On Fri, Mar 15, 2019 at 07:02:23AM +0900, Tetsuo Handa wrote:
> On 2019/03/15 5:42, Alexey Dobriyan wrote:
> > PTR_ERR((void *)map_addr) == -EEXIST
> >
> > is a very complicated way of doing the obvious.
>
> Michal suggested me to explicitly use PTR_ERR()

without any explanation why...

I wonder what documentation does this line need?

map_addr == -EEXIST


> for documentation purpose in
> a reply mail to https://lkml.kernel.org/r/20180418115546.GZ17484@xxxxxxxxxxxxxx .
>
> >
> > Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
> > ---
> >
> > fs/binfmt_elf.c | 3 +--
> > 1 file changed, 1 insertion(+), 2 deletions(-)
> >
> > --- a/fs/binfmt_elf.c
> > +++ b/fs/binfmt_elf.c
> > @@ -375,8 +375,7 @@ static unsigned long elf_map(struct file *filep, unsigned long addr,
> > } else
> > map_addr = vm_mmap(filep, addr, size, prot, type, off);
> >
> > - if ((type & MAP_FIXED_NOREPLACE) &&
> > - PTR_ERR((void *)map_addr) == -EEXIST)
> > + if ((type & MAP_FIXED_NOREPLACE) && map_addr == -EEXIST)
> > pr_info("%d (%s): Uhuuh, elf segment at %px requested but the memory is mapped already\n",
> > task_pid_nr(current), current->comm, (void *)addr);
> >
> >
>