From: Arnd Bergmann <arnd@arndb.de>
To: Christoph Hellwig <hch@infradead.org>
Cc: linux-arch <linux-arch@vger.kernel.org>,
kexec@lists.infradead.org,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
Linux-MM <linux-mm@kvack.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Andrew Morton <akpm@linux-foundation.org>,
Linux ARM <linux-arm-kernel@lists.infradead.org>,
Eric Biederman <ebiederm@xmission.com>
Subject: Re: [PATCH 4/4] mm: remove compat numa syscalls
Date: Sat, 26 Sep 2020 17:14:46 +0200 [thread overview]
Message-ID: <CAK8P3a0VKObd8BR0x-+fHKizEwhYJ-8YwEN6rKhTHU34G=ADbg@mail.gmail.com> (raw)
In-Reply-To: <20200919054148.GL30063@infradead.org>
On Sat, Sep 19, 2020 at 7:41 AM Christoph Hellwig <hch@infradead.org> wrote:
> On Fri, Sep 18, 2020 at 03:24:39PM +0200, Arnd Bergmann wrote:
> > +static int get_bitmap(unsigned long *mask, const unsigned long __user *nmask,
> > + unsigned long maxnode)
> > +{
> > + unsigned long nlongs = BITS_TO_LONGS(maxnode);
> > + int ret;
> > +
> > + if (in_compat_syscall())
> > + ret = compat_get_bitmap(mask, (void __user *)nmask, maxnode);
>
> I'd either pass void __user all the way, or do an explicit case from
> the native to the compat version in the compat handler.
Changed to
if (in_compat_syscall())
ret = compat_get_bitmap(mask,
(const compat_ulong_t __user *)nmask,
maxnode);
> > + else
> > + ret = copy_from_user(mask, nmask, nlongs*sizeof(unsigned long));
>
> That whole BITS_TO_LONGS(b) * sizeof(unsigned long) pattern is
> duplicated in various places including the checking of compat vs native
> and probably want a helper that includes the in_compat_syscall() check.
I don't see what you mean here. I can see how having the helper would
simplify copy_nodes_to_user(), but not how it can be shared with the
use in get_bitmap()/get_nodes().
Arnd
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prev parent reply other threads:[~2020-09-26 15:17 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-18 13:24 [PATCH 0/4] syscalls: remove compat_alloc_user_space callers Arnd Bergmann
2020-09-18 13:24 ` [PATCH 1/4] x86: add __X32_COND_SYSCALL() macro Arnd Bergmann
2020-09-19 5:35 ` Christoph Hellwig
2020-09-19 16:23 ` Andy Lutomirski
2020-09-19 17:14 ` hpa
2020-09-19 17:39 ` Andy Lutomirski
2020-09-19 17:45 ` Brian Gerst
2020-09-18 13:24 ` [PATCH 2/4] kexec: remove compat_sys_kexec_load syscall Arnd Bergmann
2020-09-19 5:37 ` Christoph Hellwig
2020-09-26 21:10 ` Arnd Bergmann
2020-09-18 13:24 ` [PATCH 3/4] mm: remove compat_sys_move_pages Arnd Bergmann
2020-09-19 5:38 ` Christoph Hellwig
2020-09-26 15:21 ` Arnd Bergmann
2020-09-18 13:24 ` [PATCH 4/4] mm: remove compat numa syscalls Arnd Bergmann
2020-09-19 5:41 ` Christoph Hellwig
2020-09-26 15:14 ` Arnd Bergmann [this message]
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