From: Al Viro <viro@ZenIV.linux.org.uk>
To: Dan Williams <dan.j.williams@intel.com>
Cc: Alan Cox <alan@linux.intel.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
linux-arch@vger.kernel.org, Andi Kleen <ak@linux.intel.com>,
Kees Cook <keescook@chromium.org>,
kernel-hardening@lists.openwall.com,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
the arch/x86 maintainers <x86@kernel.org>,
Ingo Molnar <mingo@redhat.com>, "H. Peter Anvin" <hpa@zytor.com>,
Thomas Gleixner <tglx@linutronix.de>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths
Date: Wed, 17 Jan 2018 20:05:32 +0000 [thread overview]
Message-ID: <20180117200532.GX13338@ZenIV.linux.org.uk> (raw)
In-Reply-To: <CAPcyv4iYVcCZxdd5wHDf2av8F=E1F7UGTX9uVzX68KkrJ1ZuQQ@mail.gmail.com>
On Wed, Jan 17, 2018 at 11:54:12AM -0800, Dan Williams wrote:
> On Wed, Jan 17, 2018 at 10:52 AM, Al Viro <viro@zeniv.linux.org.uk> wrote:
> > On Wed, Jan 17, 2018 at 02:17:26PM +0000, Alan Cox wrote:
> [..]
> > Incidentally, what about copy_to_iter() and friends? They
> > check iov_iter flavour and go either into the "copy to kernel buffer"
> > or "copy to userland" paths. Do we need to deal with mispredictions
> > there? We are calling a bunch of those on read()...
> >
>
> Those should be protected by the conversion of __uaccess_begin to
> __uaccess_begin_nospec that includes the lfence.
Huh? What the hell does it do to speculative execution of "memcpy those
suckers" branch?
next prev parent reply other threads:[~2018-01-17 20:05 UTC|newest]
Thread overview: 59+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-13 18:17 [PATCH v3 0/9] core, x86: prevent bounds-check bypass via speculative execution Dan Williams
2018-01-13 18:17 ` [PATCH v3 1/9] Documentation: document array_ptr Dan Williams
2018-01-13 18:17 ` [PATCH v3 2/9] arm64: implement ifence_array_ptr() Dan Williams
2018-01-13 18:17 ` [PATCH v3 3/9] arm: " Dan Williams
2018-01-13 18:17 ` [PATCH v3 4/9] x86: implement ifence() Dan Williams
2018-01-13 18:17 ` [PATCH v3 5/9] x86: implement ifence_array_ptr() and array_ptr_mask() Dan Williams
2018-01-13 18:17 ` [PATCH v3 6/9] asm/nospec: mask speculative execution flows Dan Williams
2018-01-13 18:18 ` [PATCH v3 7/9] x86: introduce __uaccess_begin_nospec and ASM_IFENCE Dan Williams
2018-01-13 18:18 ` [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths Dan Williams
2018-01-13 19:05 ` Linus Torvalds
2018-01-13 19:33 ` Linus Torvalds
2018-01-13 20:22 ` Eric W. Biederman
2018-01-16 22:23 ` Dan Williams
[not found] ` <CA+55aFxAFG5czVmCyhYMyHmXLNJ7pcXxWzusjZvLRh_qTGHj6Q@mail.gmail.com>
2018-01-16 22:41 ` Linus Torvalds
2018-01-17 14:17 ` Alan Cox
2018-01-17 18:52 ` Al Viro
2018-01-17 19:54 ` Dan Williams
2018-01-17 20:05 ` Al Viro [this message]
2018-01-17 20:14 ` Dan Williams
2018-01-18 3:06 ` [RFC][PATCH] get rid of the use of set_fs() (by way of kernel_recvmsg()) in sunrpc Al Viro
2018-01-18 3:16 ` Linus Torvalds
2018-01-18 4:43 ` Al Viro
2018-01-18 16:29 ` Christoph Hellwig
2018-01-18 17:10 ` Al Viro
2018-01-18 19:31 ` Al Viro
2018-01-18 19:37 ` [PATCH 01/10] net: separate SIOCGIFCONF handling from dev_ioctl() Al Viro
2018-01-18 19:37 ` [PATCH 02/10] devinet_ioctl(): take copyin/copyout to caller Al Viro
2018-01-22 16:40 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 03/10] ip_rt_ioctl(): take copyin " Al Viro
2018-01-22 16:43 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 04/10] kill dev_ifsioc() Al Viro
2018-01-22 16:47 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 05/10] kill bond_ioctl() Al Viro
2018-01-22 16:48 ` Christoph Hellwig
2018-01-18 19:37 ` [PATCH 06/10] kill dev_ifname32() Al Viro
2018-01-18 19:37 ` [PATCH 07/10] lift handling of SIOCIW... out of dev_ioctl() Al Viro
2018-01-18 19:37 ` [PATCH 08/10] ipconfig: use dev_set_mtu() Al Viro
2018-01-18 19:37 ` [PATCH 09/10] dev_ioctl(): move copyin/copyout to callers Al Viro
2018-01-18 19:37 ` [PATCH 10/10] kill kernel_sock_ioctl() Al Viro
2018-01-22 16:49 ` Christoph Hellwig
2018-01-24 20:52 ` David Miller
2018-01-25 0:01 ` Al Viro
2018-01-25 0:21 ` Al Viro
2018-01-25 4:11 ` David Miller
2018-01-22 16:40 ` [PATCH 01/10] net: separate SIOCGIFCONF handling from dev_ioctl() Christoph Hellwig
2018-01-18 20:33 ` [RFC][PATCH] get rid of the use of set_fs() (by way of kernel_recvmsg()) in sunrpc Al Viro
2018-01-19 3:27 ` Al Viro
2018-01-17 19:26 ` [PATCH v3 8/9] x86: use __uaccess_begin_nospec and ASM_IFENCE in get_user paths Linus Torvalds
2018-01-17 20:01 ` Eric Dumazet
2018-01-18 16:38 ` Christoph Hellwig
2018-01-18 16:49 ` Linus Torvalds
2018-01-18 18:12 ` Al Viro
2018-01-17 4:30 ` Dan Williams
2018-01-17 6:28 ` Al Viro
2018-01-17 6:50 ` Dan Williams
2018-01-17 10:07 ` David Laight
2018-01-17 18:12 ` Dan Williams
2018-01-17 19:16 ` Linus Torvalds
2018-01-13 18:18 ` [PATCH v3 9/9] vfs, fdtable: prevent bounds-check bypass via speculative execution Dan Williams
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