On Fri 15-03-19 19:06:56, Alexey Dobriyan wrote: > On Fri, Mar 15, 2019 at 07:53:27AM +0100, Michal Hocko wrote: > > On Thu 14-03-19 23:45:48, Alexey Dobriyan wrote: > > > Use %lx, save a cast. > > > > > > "addr" is userspace address so using (and mangling) pointer was never > > > necessary. > > > > There shouldn't be any mangling AFAIU. Documentation for pointer() > > says > > > > * - 'x' For printing the address. Equivalent to "%lx". > > The implication of using %p/%px is that the address is kernel pointer > which should or should not be mangled.
And px is not mangled AFAICS. > But "map_addr" is not a kernel pointer. Which should be irrelevant. It is a pointer and my understanding is that %p$FOO should be used preferably for any pointers. > And it saves a cast. Is this really such an improvement? Why? > > > --- a/fs/binfmt_elf.c > > > +++ b/fs/binfmt_elf.c > > > @@ -376,8 +376,8 @@ static unsigned long elf_map(struct file *filep, > > > unsigned long addr, > > > map_addr = vm_mmap(filep, addr, size, prot, type, off); > > > > > > 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); > > > + pr_info("%d (%s): Uhuuh, elf segment at %lx requested but the > > > memory is mapped already\n", > > > + task_pid_nr(current), current->comm, addr); -- Michal Hocko SUSE Labs