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https://github.com/Zenithsiz/ftmemsim-valgrind.git
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3ea8d43270
Patch contributed by Will Schmidt <will_schmidt@vnet.ibm.com>
This problem was initially reported by Tulio, he assisted me in
identifying the underlying issue here.
This was discovered on a Power10, and occurs since the ISA 3.1 support
check uses the brh instruction via a hardcoded ".long 0x7f1401b6" asm stanza.
That encoding writes to r20, and since the stanza does not contain a clobber
the compiler did not know to save or restore that register upon entry or exit.
The junk value remaining in r20 subsequently caused a segfault.
This patch adds clobber masks to the instruction stanzas, as well as
updates the associated comments to clarify which registers are being
used.
As part of this change I've also
- updated the .long for the cnttzw instruction to write to r20, and
zeroed the reserved bits from that instruction so it is properly
decoded by the disassembler.
- updated the .long for the dadd instruction to write to f0.
I've inspected the current codegen with these changes in place, and
confirm that r20 is now saved and restored on entry and exit from the
machine_get_hwcaps() function.
bugzilla 447995 Valgrind segfault on power10 due to hwcap checking code
Release notes for Valgrind
~~~~~~~~~~~~~~~~~~~~~~~~~~
If you are building a binary package of Valgrind for distribution,
please read README_PACKAGERS. It contains some important information.
If you are developing Valgrind, please read README_DEVELOPERS. It contains
some useful information.
For instructions on how to build/install, see the end of this file.
If you have problems, consult the FAQ to see if there are workarounds.
Executive Summary
~~~~~~~~~~~~~~~~~
Valgrind is a framework for building dynamic analysis tools. There are
Valgrind tools that can automatically detect many memory management
and threading bugs, and profile your programs in detail. You can also
use Valgrind to build new tools.
The Valgrind distribution currently includes six production-quality
tools: a memory error detector, two thread error detectors, a cache
and branch-prediction profiler, a call-graph generating cache and
branch-prediction profiler, and a heap profiler. It also includes
three experimental tools: a heap/stack/global array overrun detector,
a different kind of heap profiler, and a SimPoint basic block vector
generator.
Valgrind is closely tied to details of the CPU, operating system and to
a lesser extent, compiler and basic C libraries. This makes it difficult
to make it portable. Nonetheless, it is available for the following
platforms:
- X86/Linux
- AMD64/Linux
- PPC32/Linux
- PPC64/Linux
- ARM/Linux
- ARM64/Linux
- x86/macOS
- AMD64/macOS
- S390X/Linux
- MIPS32/Linux
- MIPS64/Linux
- nanoMIPS/Linux
- X86/Solaris
- AMD64/Solaris
- X86/FreeBSD
- AMD64/FreeBSD
Note that AMD64 is just another name for x86_64, and Valgrind runs fine
on Intel processors. Also note that the core of macOS is called
"Darwin" and this name is used sometimes.
Valgrind is licensed under the GNU General Public License, version 2.
Read the file COPYING in the source distribution for details.
However: if you contribute code, you need to make it available as GPL
version 2 or later, and not 2-only.
Documentation
~~~~~~~~~~~~~
A comprehensive user guide is supplied. Point your browser at
$PREFIX/share/doc/valgrind/manual.html, where $PREFIX is whatever you
specified with --prefix= when building.
Building and installing it
~~~~~~~~~~~~~~~~~~~~~~~~~~
To install from the GIT repository:
0. Clone the code from GIT:
git clone git://sourceware.org/git/valgrind.git
There are further instructions at
http://www.valgrind.org/downloads/repository.html.
1. cd into the source directory.
2. Run ./autogen.sh to setup the environment (you need the standard
autoconf tools to do so).
3. Continue with the following instructions...
To install from a tar.bz2 distribution:
4. Run ./configure, with some options if you wish. The only interesting
one is the usual --prefix=/where/you/want/it/installed.
5. Run "make".
6. Run "make install", possibly as root if the destination permissions
require that.
7. See if it works. Try "valgrind ls -l". Either this works, or it
bombs out with some complaint. In that case, please let us know
(see http://valgrind.org/support/bug_reports.html).
Important! Do not move the valgrind installation into a place
different from that specified by --prefix at build time. This will
cause things to break in subtle ways, mostly when Valgrind handles
fork/exec calls.
The Valgrind Developers