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From: Andy Lutomirski <luto@amacapital.net>
To: Jan Beulich <JBeulich@suse.com>,
	hpa@zytor.com, linux-kernel@vger.kernel.org
Cc: Boris Ostrovsky <ostr.lkml@gmail.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	x86@kernel.org, Andy Lutomirski <luto@amacapital.net>
Subject: [PATCH 0/2] Revert to 32-bit 3.15-style vvar and vdso stripping
Date: Thu, 10 Jul 2014 18:13:14 -0700	[thread overview]
Message-ID: <cover.1405040914.git.luto@amacapital.net> (raw)

The fancy ideas of aggressively stripping the vdso and placing the
vvar data after the vdso have been considerably more painful than I
hoped.  This reverts to using objcopy -S to strip the vdso (thus
eliminating the whole fake section mechanism and all of its
attendent build-time fragility, I hope) and places the vvar data
before the vdso.

The latter is a bit messy: ELF wasn't really designed to have
symbols at negative virtual addresses.  I think I got all the
bitness issues and cross-compilation stuff right, but I'm not
well-equipped to test that.  The kbuild robot hasn't complained yet,
though.

I don't know whether this is 3.16 material.  I'm not aware of an
actual problem at this point, but the current state of affairs is
quite fragile.

Applies on top of tip/x86/urgent as of a few minutes ago.


Andy Lutomirski (2):
  x86,vdso: Move the vvar area before the vdso text
  x86,vdso: Get rid of the fake section mechanism

 arch/x86/include/asm/vdso.h       |  18 +--
 arch/x86/vdso/Makefile            |  16 ++-
 arch/x86/vdso/vdso-fakesections.c |  21 ----
 arch/x86/vdso/vdso-layout.lds.S   |  44 ++++----
 arch/x86/vdso/vdso2c.c            | 128 ++++++++++++++++-----
 arch/x86/vdso/vdso2c.h            | 227 +++++++-------------------------------
 arch/x86/vdso/vma.c               |  20 ++--
 7 files changed, 188 insertions(+), 286 deletions(-)
 delete mode 100644 arch/x86/vdso/vdso-fakesections.c

-- 
1.9.3


             reply	other threads:[~2014-07-11  1:13 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-07-11  1:13 Andy Lutomirski [this message]
2014-07-11  1:13 ` [PATCH 1/2] x86,vdso: Move the vvar area before the vdso text Andy Lutomirski
2014-07-12  0:21   ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski
2014-07-11  1:13 ` [PATCH 2/2] x86,vdso: Get rid of the fake section mechanism Andy Lutomirski
2014-07-12  0:21   ` [tip:x86/vdso] x86, vdso: " tip-bot for Andy Lutomirski

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