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From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Subject: [Qemu-devel] [Bug 1625295] Re: qemu-arm dies with libarmmem inside ld.so.preload
Date: Tue, 20 Sep 2016 13:47:58 -0000	[thread overview]
Message-ID: <20160920134758.6513.7111.malone@gac.canonical.com> (raw)
In-Reply-To: 20160919174005.12059.42887.malonedeb@gac.canonical.com

This turns out to be nothing to do with setend. We're doing something wrong emulating the following nasty hack:
https://github.com/bavison/arm-mem/blob/master/architecture.S

.arm
architecture:
        sub     pc, pc, #1  @ is an interworking branch on ARMv7, not ARMv6
        and     a1, a4, a1  @ second word interpreted as 'B .+0xA' if Thumb
        mov     a1, #6
        bx      lr
.thumb
        mov     a1, #7
        bx      lr

so after the 'sub pc, pc, #1' (which in my debug trace is at address
0xb6f086dc) QEMU next tries to execute from 0xb6f086e2 in ARM mode,
which is neither of the two expected outcomes. As it happens we hit an
undefined instruction pretty much immediately afterwards:

0xb6f086e2:  0006e003      andeq        lr, r6, r3
0xb6f086e6:  ff1ee3a0      undefined instruction 0xff1ee3a0

-- 
You received this bug notification because you are a member of qemu-
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https://bugs.launchpad.net/bugs/1625295

Title:
  qemu-arm dies with libarmmem inside ld.so.preload

Status in QEMU:
  New

Bug description:
  When running raspbian inside qemu,the user has to first comment out
  the following line from /etc/ld.so.conf:

  /usr/lib/arm-linux-gnueabihf/libarmmem.so

  
  Will future qemus will be able to work without changine /etc/ld.so.conf ?

To manage notifications about this bug go to:
https://bugs.launchpad.net/qemu/+bug/1625295/+subscriptions

  parent reply	other threads:[~2016-09-20 13:55 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-09-19 17:40 [Qemu-devel] [Bug 1625295] [NEW] qemu-arm dies with libarmmem inside ld.so.preload Stu
2016-09-19 20:27 ` [Qemu-devel] [Bug 1625295] " Peter Maydell
2016-09-19 23:02   ` Stu
2016-09-20  9:26     ` Peter Maydell
2016-09-20  9:53       ` Stu
2016-09-20 10:22 ` Peter Maydell
2016-09-20 12:50   ` Stu
2016-09-20 13:29 ` Peter Maydell
2016-09-20 13:41   ` Stu
2016-09-20 13:47 ` Peter Maydell [this message]
2016-09-20 14:27 ` Peter Maydell
2016-10-04 14:55 ` Peter Maydell
2016-10-05 10:11   ` Stu
2016-10-19 23:52 ` Stu
2016-10-20  7:41 ` Peter Maydell
2016-10-20 10:18   ` Stu
2017-01-11  6:54 ` Thomas Huth

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