From: Peter Maydell <peter.maydell@linaro.org>
To: Richard Henderson <rth@twiddle.net>
Cc: blauwirbel@gmail.com, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 01/13] linux-user: Use memcpy in get_user/put_user.
Date: Mon, 17 Sep 2012 17:06:23 +0100 [thread overview]
Message-ID: <CAFEAcA-fCfQMkLLEzQ_XS3RTYOSVX9bc-7qS_0zmiSOo-HDkGA@mail.gmail.com> (raw)
In-Reply-To: <1347895732-22212-2-git-send-email-rth@twiddle.net>
On 17 September 2012 16:28, Richard Henderson <rth@twiddle.net> wrote:
> Not sure whether this is a gcc bug, but on sparc we wind up
> trying to use std to an unaligned address. The patch does
> work around the problem.
>
> Signed-off-by: Richard Henderson <rth@twiddle.net>
As far as the code is concerned:
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
but please rewrite the commit message to be more sure of itself :-)
Specifically, this is required because the guest's alignment
requirements may be laxer than those of the host, so we can't
take a hptr for a 16/32/64 bit type (which only has the alignment
restrictions of the guest) and do a gcc pointer dereference on it
(which may assume the alignment restrictions of the host).
Does anybody know the semantics of the kernel's copy_from_user()?
Does it fail on misaligned userspace structs or does it allow
them?
-- PMM
next prev parent reply other threads:[~2012-09-17 16:06 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-16 0:05 [Qemu-devel] [PATCH] fix gcc warnings when RESERVED_VA is 0 Mike Frysinger
2012-09-16 9:58 ` Peter Maydell
2012-09-16 10:25 ` Blue Swirl
2012-09-17 15:28 ` [Qemu-devel] [PATCH v2 00/13] Sparc TCG cleanup Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 01/13] linux-user: Use memcpy in get_user/put_user Richard Henderson
2012-09-17 15:35 ` Peter Maydell
2012-09-17 15:40 ` Richard Henderson
2012-09-17 16:06 ` Peter Maydell [this message]
2012-09-17 15:28 ` [Qemu-devel] [PATCH 02/13] tcg-sparc: Hack in qemu_ld/st64 for 32-bit Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 03/13] tcg-sparc: Fix ADDX opcode Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 04/13] tcg-sparc: Assume v9 cpu always, i.e. force v8plus in 32-bit mode Richard Henderson
2012-09-17 16:04 ` Andreas Färber
2012-09-17 17:05 ` Richard Henderson
2012-09-17 19:25 ` Blue Swirl
2012-09-17 21:52 ` Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 05/13] tcg-sparc: Fix qemu_ld/st to handle 32-bit host Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 06/13] tcg-sparc: Support GUEST_BASE Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 07/13] tcg-sparc: Change AREG0 in generated code to %i0 Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 08/13] tcg-sparc: Clean up cruft stemming from attempts to use global registers Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 09/13] tcg-sparc: Mask shift immediates to avoid illegal insns Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 10/13] tcg-sparc: Use defines for temporaries Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 11/13] tcg-sparc: Add %g/%o registers to alloc_order Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 12/13] tcg-sparc: Fix and enable direct TB chaining Richard Henderson
2012-09-17 15:28 ` [Qemu-devel] [PATCH 13/13] tcg: Fix !USE_DIRECT_JUMP Richard Henderson
2012-09-17 15:50 ` Andreas Färber
2012-09-21 20:21 ` Stefan Weil
2012-09-21 10:28 ` Aurelien Jarno
2012-09-21 18:16 ` Aurelien Jarno
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