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From: Christoph Hellwig <hch@lst.de>
To: x86@kernel.org, Jan Kara <jack@suse.com>
Cc: linux-arm-kernel@lists.infradead.org,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-api@vger.kernel.org, linux-arch@vger.kernel.org
Subject: improve compat handling for the i386 u64 alignment quirk
Date: Sun, 26 Jul 2020 18:03:57 +0200	[thread overview]
Message-ID: <20200726160401.311569-1-hch@lst.de> (raw)

Hi all,

the i386 ABI is a little special in that it uses less than natural
alignment for 64-bit integer types (u64 and s64), and a significant
amount of our compat handlers deals with just that.  Unfortunately
there is no good way to check for this specific quirk at runtime,
similar how in_compat_syscall() checks for a compat syscall.  This
series adds such a check, and then uses the quota code as an example
of how this improves the compat handling.  I have a few other places
in mind where this will also be useful going forward.

Diffstat:
 b/arch/arm64/include/asm/compat.h        |    2 
 b/arch/arm64/include/asm/stat.h          |    2 
 b/arch/arm64/kernel/process.c            |    1 
 b/arch/arm64/kernel/ptrace.c             |    1 
 b/arch/mips/include/asm/compat.h         |    2 
 b/arch/parisc/include/asm/compat.h       |    2 
 b/arch/powerpc/include/asm/compat.h      |    2 
 b/arch/s390/include/asm/compat.h         |    2 
 b/arch/sparc/include/asm/compat.h        |    3 
 b/arch/x86/entry/syscalls/syscall_32.tbl |    2 
 b/arch/x86/include/asm/compat.h          |    3 
 b/fs/quota/Kconfig                       |    5 -
 b/fs/quota/Makefile                      |    1 
 b/fs/quota/compat.h                      |   34 ++++++++
 b/fs/quota/quota.c                       |   73 +++++++++++++++---
 b/include/linux/compat.h                 |   17 ++++
 b/include/linux/quotaops.h               |    3 
 b/kernel/sys_ni.c                        |    1 
 fs/quota/compat.c                        |  120 -------------------------------
 19 files changed, 114 insertions(+), 162 deletions(-)

             reply	other threads:[~2020-07-26 16:04 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-07-26 16:03 Christoph Hellwig [this message]
2020-07-26 16:03 ` [PATCH 1/4] arm64: stop using <asm/compat.h> directly Christoph Hellwig
2020-07-30 17:34   ` Nathan Chancellor
2020-07-31  8:41     ` Naresh Kamboju
2020-07-26 16:03 ` [PATCH 2/4] compat: lift compat_s64 and compat_u64 to <linux/compat.h> Christoph Hellwig
2020-07-29  6:08   ` [PATCH 2/4 v2] " Christoph Hellwig
2020-07-26 16:04 ` [PATCH 3/4] compat: add a compat_need_64bit_alignment_fixup() helper Christoph Hellwig
2020-07-26 16:04 ` [PATCH 4/4] quota: simplify the quotactl compat handling Christoph Hellwig
2020-07-26 16:32   ` Al Viro
2020-07-26 16:34     ` Christoph Hellwig
2020-07-26 16:37       ` Al Viro
2020-07-27 12:41   ` Jan Kara
2020-07-27 15:56     ` Al Viro
2020-07-27 21:31       ` Jan Kara
2020-07-28  1:49         ` Al Viro

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