https://gcc.gnu.org/bugzilla/show_bug.cgi?id=86832
Bug ID: 86832
Summary: GCC v8.2.0 tries to use native TLS with
-fstack-protector-strong on Windows (mingw-w64)
Product: gcc
Version: lto
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: johannes.schindelin at gmx dot de
Target Milestone: ---
When I try to compile this program:
-- snip --
static void a1(void *p) { }
int main(int argc, char **argv) {
int i;
a1(&i);
return 0;
}
-- snap --
using
gcc -o a1.o -c -fstack-protector-strong a1.c
gcc -fstack-protector-strong -o a1.exe a1.o
the resulting a1.exe causes a segmentation fault in `main()`. The offending
assembler instruction is this:
0x40156f <main+20>: mov %fs:0x0,%rax
The good mingw-w64 people pointed out that this looks like native TLS, but
mingw-w64 only supports emulated TLS.
When compiling without -fstack-protector-strong, everything works.
Output of `gcc -v`:
Using built-in specs.
COLLECT_GCC=C:\git-sdk-64-ci\mingw64\bin\gcc.exe
COLLECT_LTO_WRAPPER=C:/git-sdk-64-ci/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/8.2.0/lto-wrapper.exe
Target: x86_64-w64-mingw32
Configured with: ../gcc-8.2.0/configure --prefix=/mingw64
--with-local-prefix=/mingw64/local --build=x86_64-w64-mingw32
--host=x86_64-w64-mingw32 --target=x86_64-w64-mingw32
--with-native-system-header-dir=/mingw64/x86_64-w64-mingw32/include
--libexecdir=/mingw64/lib --enable-bootstrap --with-arch=x86-64
--with-tune=generic --enable-languages=ada,c,lto,c++,objc,obj-c++,fortran
--enable-shared --enable-static --enable-libatomic --enable-threads=posix
--enable-graphite --enable-fully-dynamic-string
--enable-libstdcxx-filesystem-ts=yes --enable-libstdcxx-time=yes
--disable-libstdcxx-pch --disable-libstdcxx-debug --disable-isl-version-check
--enable-lto --enable-libgomp --disable-multilib --enable-checking=release
--disable-rpath --disable-win32-registry --disable-nls --disable-werror
--disable-symvers --with-libiconv --with-system-zlib --with-gmp=/mingw64
--with-mpfr=/mingw64 --with-mpc=/mingw64 --with-isl=/mingw64
--with-pkgversion='Rev1, Built by MSYS2 project'
--with-bugurl=https://sourceforge.net/projects/msys2 --with-gnu-as
--with-gnu-ld
Thread model: posix
gcc version 8.2.0 (Rev1, Built by MSYS2 project)
