[Bug c/108746] New: backtrace overwrites other memory

[Bug c/108746] New: backtrace overwrites other memory

[vitiral at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108746

            Bug ID: 108746
           Summary: backtrace overwrites other memory
           Product: gcc
           Version: 12.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: vitiral at gmail dot com
  Target Milestone: ---

Created attachment 54443
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=54443&action=edit
output of make (gcc)

I am using the backtrace() function and it seems to be overwriting memory I
didn't give it. The value in a different region of memory changes after
executing the below code:

  void* m[100] = {0};
  S len = backtrace(m, 100);


In the below logs, addrOver is the address that is getting overwritten, trace
is the value being sent to backtrace. You can see that before and after are
changing.

??? Kern_handleSig addrOver=94A7444
??? Kern_handleSig trace   =FFEB3D18
??? Kern_handleSig before  =94A4FC8
??? Kern_handleSig after   =94A754C

# Command to build
git clone git@github.com:civboot/fngi.git
git clone git@github.com:civboot/civc.git
git clone git@github.com:civboot/cxt.git 
git clone git@github.com:civboot/zoa.git 
cd fngi
git checkout branch origin/gccBug
make &> /tmp/make.txt

make.txt is attached. The top of it reads:


Using built-in specs.      
COLLECT_GCC=gcc     
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/12/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Debian 12.2.0-10'
--with-bugurl=file:///usr/share/doc/gcc-12/README.Bugs
--enable-languages=c,ada,c++,go,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-
major-version-only --program-suffix=-12 --program-prefix=x86_64-linux-gnu-
--enable-shared --enable-linker-build-id --libexecdir=/usr/lib
--without-included-gettext --enable-threads=posix --libdir=/usr/lib --enab
le-nls --enable-clocale=gnu --enable-libstdcxx-debug
--enable-libstdcxx-time=yes --with-default-libstdcxx-abi=new
--enable-gnu-unique-object --disable-vtable-verify --enable-plugin
--enable-default-pie --with-sys
tem-zlib --enable-libphobos-checking=release --with-target-system-zlib=auto
--enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,m
x32 --enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-12-hWCYKv/gcc-12-12.2.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-12-hWCYKv/gcc-12-12.2.0/debian/tmp-gcn/usr
--enable-o
ffload-defaulted --without-cuda-driver --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix 
Supported LTO compression algorithms: zlib zstd
gcc version 12.2.0 (Debian 12.2.0-10) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-m32' '-no-pie' '-g' '-rdynamic'
'-Wall' '-Wno-pointer-sign' '-Wformat=0' '-I' '../civc' '-o' 'bin/tests'
'-mtune=generic' '-march=i686' '-dumpdir' 'bin/tests-'
 /usr/lib/gcc/x86_64-linux-gnu/12/cc1 -E -quiet -v -I ../civc -imultilib 32
-imultiarch i386-linux-gnu ../civc/civ/civ.c -m32 -mtune=generic -march=i686
-Wall -Wno-pointer-sign -Wformat=0 -g -fworking-directory -
fpch-preprocess -fasynchronous-unwind-tables -o bin/tests-civ.i

[Bug c/108746] backtrace overwrites other memory

[vitiral at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108746

--- Comment #1 from Garrett vitiral <vitiral at gmail dot com> ---
Sorry, I should have used standard types instead of my aliases for the example
code

  void* m[100] = {0};
  size_t len = backtrace(m, 100);

[Bug c/108746] backtrace overwrites other memory

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108746

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |RESOLVED
         Resolution|---                         |MOVED

--- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Backtrace is not provided by GCC.
In your case it is provided by glibc. Please report it to them.

[Bug c/108746] backtrace overwrites other memory

[vitiral at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108746

--- Comment #3 from Garrett vitiral <vitiral at gmail dot com> ---
Thanks, will do!

[Bug c/108746] backtrace overwrites other memory

[vitiral at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108746

--- Comment #4 from Garrett vitiral <vitiral at gmail dot com> ---
https://sourceware.org/bugzilla/show_bug.cgi?id=30106

thanks again