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Jiri Olsa dac66c47df perf report: Fix memory corruption in --branch-history mode --branch-history
[ Upstream commit e3ebaa4651 ]

Jin Yao reported memory corrupton in perf report with
branch info used for stack trace:

  > Following command lines will cause perf crash.

  > perf record -j call -g -a <application>
  > perf report --branch-history
  >
  > *** Error in `perf': double free or corruption (!prev): 0x00000000104aa040 ***
  > ======= Backtrace: =========
  > /lib/x86_64-linux-gnu/libc.so.6(+0x77725)[0x7f6b37254725]
  > /lib/x86_64-linux-gnu/libc.so.6(+0x7ff4a)[0x7f6b3725cf4a]
  > /lib/x86_64-linux-gnu/libc.so.6(cfree+0x4c)[0x7f6b37260abc]
  > perf[0x51b914]
  > perf(hist_entry_iter__add+0x1e5)[0x51f305]
  > perf[0x43cf01]
  > perf[0x4fa3bf]
  > perf[0x4fa923]
  > perf[0x4fd396]
  > perf[0x4f9614]
  > perf(perf_session__process_events+0x89e)[0x4fc38e]
  > perf(cmd_report+0x15d2)[0x43f202]
  > perf[0x4a059f]
  > perf(main+0x631)[0x427b71]
  > /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7f6b371fd830]
  > perf(_start+0x29)[0x427d89]

For the cumulative output, we allocate the he_cache array based on the
--max-stack option value and populate it with data from 'callchain_cursor'.

The --max-stack option value does not ensure now the limit for number of
callchain_cursor nodes, so the cumulative iter code will allocate smaller array
than it's actually needed and cause above corruption.

I think the --max-stack limit does not apply here anyway, because we add
callchain data as normal hist entries, while the --max-stack control the limit
of single entry callchain depth.

Using the callchain_cursor.nr as he_cache array count to fix this. Also
removing struct hist_entry_iter::max_stack, because there's no longer any use
for it.

We need more fixes to ensure that the branch stack code follows properly the
logic of --max-stack, which is not the case at the moment.

Original-patch-by: Jin Yao <yao.jin@linux.intel.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Reported-by: Jin Yao <yao.jin@linux.intel.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Kan Liang <kan.liang@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20180216123619.GA9945@krava
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-30 07:52:40 +02:00
arch x86/apic: Set up through-local-APIC mode on the boot CPU if 'noapic' specified 2018-05-30 07:52:39 +02:00
block block: display the correct diskname for bio 2018-05-30 07:52:09 +02:00
certs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto PKCS#7: fix direct verification of SignerInfo signature 2018-05-30 07:52:01 +02:00
Documentation pinctrl: artpec6: dt: add missing pin group uart5nocts 2018-05-30 07:52:37 +02:00
drivers drm/rockchip: Respect page offset for PRIME mmap calls 2018-05-30 07:52:39 +02:00
firmware License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs udf: Provide saner default for invalid uid / gid 2018-05-30 07:52:38 +02:00
include vlan: Fix vlan insertion for packets without ethernet header 2018-05-30 07:52:22 +02:00
init kmemcheck: stop using GFP_NOTRACK and SLAB_NOTRACK 2018-02-22 15:42:23 +01:00
ipc ipc/shm: fix shmat() nil address after round-down when remapping 2018-05-30 07:51:49 +02:00
kernel rcu: Call touch_nmi_watchdog() while printing stall warnings 2018-05-30 07:52:39 +02:00
lib lib/test_kmod.c: fix limit check on number of test devices created 2018-05-30 07:52:14 +02:00
mm mm: thp: fix potential clearing to referenced flag in page_idle_clear_pte_refs_one() 2018-05-30 07:52:24 +02:00
net net/smc: pay attention to MAX_ORDER for CQ entries 2018-05-30 07:52:32 +02:00
samples samples/bpf: Partially fixes the bpf.o build 2018-04-26 11:02:12 +02:00
scripts builddeb: Fix header package regarding dtc source links 2018-05-30 07:52:21 +02:00
security ima: Fallback to the builtin hash algorithm 2018-05-30 07:52:29 +02:00
sound ALSA: vmaster: Propagate slave error 2018-05-30 07:52:35 +02:00
tools perf report: Fix memory corruption in --branch-history mode --branch-history 2018-05-30 07:52:40 +02:00
usr initramfs: fix initramfs rebuilds w/ compression after disabling 2017-11-03 07:39:19 -07:00
virt KVM: arm/arm64: vgic: Add missing irq_lock to vgic_mmio_read_pending 2018-05-30 07:52:15 +02:00
.cocciconfig
.get_maintainer.ignore
.gitattributes .gitattributes: set git diff driver for C source code files 2016-10-07 18:46:30 -07:00
.gitignore kbuild: rpm-pkg: keep spec file until make mrproper 2018-02-13 10:19:46 +01:00
.mailmap .mailmap: Add Maciej W. Rozycki's Imagination e-mail address 2017-11-10 12:16:15 -08:00
COPYING
CREDITS MAINTAINERS: update TPM driver infrastructure changes 2017-11-09 17:58:40 -08:00
Kbuild License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
Kconfig License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
MAINTAINERS dt-bindings: Document mti,mips-cpc binding 2018-03-15 10:54:35 +01:00
Makefile Linux 4.14.44 2018-05-25 16:18:02 +02:00
README README: add a new README file, pointing to the Documentation/ 2016-10-24 08:12:35 -02:00

Linux kernel
============

This file was moved to Documentation/admin-guide/README.rst

Please notice that there are several guides for kernel developers and users.
These guides can be rendered in a number of formats, like HTML and PDF.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
See Documentation/00-INDEX for a list of what is contained in each file.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.