linux-kernel - [PATCH V2 0/4] ARM64: Fix irq generation between breakpoint and step exception

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:   Fri,  7 Jul 2017 17:33:56 +0530
From:   Pratyush Anand <panand@...hat.com>
To:     linux-arm-kernel@...ts.infradead.org, mark.rutland@....com
Cc:     will.deacon@....com, huawei.libin@...wei.com,
        Pratyush Anand <panand@...hat.com>,
        Alexander Shishkin <alexander.shishkin@...ux.intel.com>,
        Arnaldo Carvalho de Melo <acme@...nel.org>,
        Ingo Molnar <mingo@...hat.com>, linux-kernel@...r.kernel.org,
        Peter Zijlstra <peterz@...radead.org>
Subject: [PATCH V2 0/4] ARM64: Fix irq generation between breakpoint and step exception

v1 was here http://marc.info/?l=linux-arm-kernel&m=149910958418708&w=2

v1 -> v2:
- patch 1 of v1 has been modified to patch 1-3 of v2.
- Introduced a new event attribute step_needed and implemented
  hw_breakpoint_needs_single_step() (patch 1)
- Replaced usage of is_default_overflow_handler() with
  hw_breakpoint_needs_single_step(). (patch 2)
- Modified sample test to set set step_needed bit field (patch 3)

samples/hw_breakpoint/data_breakpoint.c passes with x86_64 but fails with
ARM64. Even though it has been NAKed previously on upstream [1, 2], I have
tried to come up with patches which can resolve it for ARM64 as well.

I noticed that even perf step exception can go into an infinite loop if CPU
receives an interrupt while executing breakpoint/watchpoint handler. So,
event though we are not concerned about above test, we will have to find a
solution for the perf issue.

This patchset attempts to resolve both the issue. Please review.

[1] http://marc.info/?l=linux-arm-kernel&m=149580777524910&w=2
[2] http://lists.infradead.org/pipermail/linux-arm-kernel/2016-April/425266.html

Pratyush Anand (4):
  hw_breakpoint: Add step_needed event attribute
  arm64: use hw_breakpoint_needs_single_step() to decide if step is
    needed
  hw-breakpoint: sample test: set step_needed bit field
  arm64: disable irq between breakpoint and step exception

 arch/arm64/kernel/debug-monitors.c      |  3 +++
 arch/arm64/kernel/hw_breakpoint.c       | 10 +++++-----
 arch/arm64/mm/fault.c                   | 22 ++++++++++++++++++----
 include/linux/hw_breakpoint.h           |  6 ++++++
 include/uapi/linux/perf_event.h         |  3 ++-
 kernel/events/core.c                    |  2 ++
 samples/hw_breakpoint/data_breakpoint.c |  1 +
 tools/include/uapi/linux/perf_event.h   |  3 ++-
 8 files changed, 39 insertions(+), 11 deletions(-)

-- 
2.9.3