[PATCH v2 0/2] powerpc: Emulation support for load/store instructions on LE

Path	csiph.com!1.us.feeder.erje.net!feeder.erje.net!2.eu.feeder.erje.net!news2.arglkargh.de!news.mixmin.net!aioe.org!bofh.it!news.nic.it!robomod
From	Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 0/2] powerpc: Emulation support for load/store instructions on LE
Date	Tue, 14 Feb 2017 09:10:02 +0100
Message-ID	<taGls-7GR-29@gated-at.bofh.it> (permalink)
X-Original-To	linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, mpe@ellerman.id.au
X-Mailer	git-send-email 2.1.4
X-Tm-As-Mml	disable
X-Content-Scanned	Fidelis XPS MAILER
X-Cbid	17021408-0052-0000-0000-000002164FD8
X-Ibm-Av-Detection	SAVI=unused REMOTE=unused XFE=unused
X-Cbparentid	17021408-0053-0000-0000-000007C65D3B
X-Proofpoint-Virus-Version	vendor=fsecure engine=2.50.10432:,, definitions=2017-02-14_05:,, signatures=0
X-Proofpoint-Spam-Details	rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1612050000 definitions=main-1702140084
Sender	robomod@news.nic.it
List-ID	<linux-kernel.vger.kernel.org>
X-Mailing-List	linux-kernel@vger.kernel.org
Approved	robomod@news.nic.it
Lines	36
Organization	linux.* mail to news gateway
X-Original-Cc	benh@kernel.crashing.org, paulus@samba.org, lsorense@csclub.uwaterloo.ca, oohall@gmail.com, naveen.n.rao@linux.vnet.ibm.com, ast@kernel.org, chris@distroguy.com, aneesh.kumar@linux.vnet.ibm.com, bsingharora@gmail.com, anton@samba.org, paul.gortmaker@windriver.com, bauerman@linux.vnet.ibm.com, viro@zeniv.linux.org.uk, christophe.leroy@c-s.fr, duwe@lst.de, oss@buserror.net, Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com>
X-Original-Date	Tue, 14 Feb 2017 13:32:10 +0530
X-Original-Message-ID	<1487059332-6925-1-git-send-email-ravi.bangoria@linux.vnet.ibm.com>
X-Original-Sender	linux-kernel-owner@vger.kernel.org
Xref	csiph.com linux.kernel:1580373

Show key headers only | View raw

emulate_step is the basic infrastructure which is used by number of other
kernel infrastructures like kprobe, hw-breakpoint(data breakpoint) etc.
In case of kprobe, enabling emulation of load/store instructions will
speedup the execution of probed instruction. In case of kernel-space
breakpoint, causative instruction is first get emulated before executing
user registered handler. If emulation fails, hw-breakpoint is disabled
with error. As emulate_step does not support load/store instructions on
LE, kernel-space hw-breakpoint infrastructure is broken on LE.

emulate_step() uses a number of underlying kernel functions that were
initially not enabled for LE. This has been rectified since. So, fix
emulate_step() for LE for the corresponding instructions.

Also add selftest which will run at boot if CONFIG_KPROBES_SANITY_TEST
and CONFIG_PPC64 is set.

Changes in v2:
  - Folded 2nd and 3rd patch of v1 into one patch, as suggested by Naveen

v1 link: https://www.mail-archive.com/linuxppc-dev@lists.ozlabs.org/msg110671.html

Ravi Bangoria (2):
  powerpc: Emulation support for load/store instructions on LE
  powerpc: emulate_step tests for load/store instructions

 arch/powerpc/include/asm/ppc-opcode.h |   7 +
 arch/powerpc/include/asm/sstep.h      |   8 +
 arch/powerpc/kernel/kprobes.c         |   2 +
 arch/powerpc/lib/Makefile             |   4 +
 arch/powerpc/lib/sstep.c              |  20 --
 arch/powerpc/lib/test_emulate_step.c  | 439 ++++++++++++++++++++++++++++++++++
 6 files changed, 460 insertions(+), 20 deletions(-)
 create mode 100644 arch/powerpc/lib/test_emulate_step.c

-- 
1.8.3.1

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread

Thread

[PATCH v2 0/2] powerpc: Emulation support for load/store instructions on LE Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2017-02-14 09:10 +0100
  [PATCH v2 2/2] powerpc: emulate_step tests for load/store instructions Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2017-02-14 09:10 +0100
  [PATCH v2 1/2] powerpc: Emulation support for load/store instructions on LE Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2017-02-14 09:10 +0100
    Re: [PATCH v2 1/2] powerpc: Emulation support for load/store  instructions on LE "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> - 2017-02-14 10:00 +0100
      Re: [PATCH v2 1/2] powerpc: Emulation support for load/store  instructions on LE Ravi Bangoria <ravi.bangoria@linux.vnet.ibm.com> - 2017-02-14 10:20 +0100

csiph-web