From: Alexey Dobriyan <adobriyan@gmail.com>
To: Michal Hocko <mhocko@kernel.org>
Cc: akpm@linux-foundation.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/2] elf: print userspace address with %lx
Date: Fri, 15 Mar 2019 19:06:56 +0300 [thread overview]
Message-ID: <20190315160656.GB2135@avx2> (raw)
In-Reply-To: <20190315065327.GA15672@dhcp22.suse.cz>
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. But "map_addr" is not a kernel
pointer. And it saves a cast.
> > --- 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);
next prev parent reply other threads:[~2019-03-15 16:07 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-03-14 20:45 [PATCH 2/2] elf: print userspace address with %lx Alexey Dobriyan
2019-03-15 6:53 ` Michal Hocko
2019-03-15 16:06 ` Alexey Dobriyan [this message]
2019-03-16 8:28 ` Michal Hocko
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