Hello Stefan, On Tue, Jun 20, 2023 at 8:32 PM Stefan Hajnoczi wrote: > This is caused by the stack protector compiler options, which depend on > the libc __stack_chk_fail_local symbol. liburing itself explicitly disables the stack protector, even when compiled with libc. You customize the build and use something that needs libc (stack protector). So I would say liburing upstream has taken care of this problem in the normal build. > The compile_prog check in ./configure should use the final > CFLAGS/LDFLAGS (including -ffreestanding) that liburing is compiled with > to avoid false positives. That way it can detect that nolibc won't work > with these compiler options and fall back to using libc. > > In general, I'm concerned that nolibc is fragile because the toolchain > and libc sometimes have dependencies that are activated by certain > compiler options. Some users will want libc and others will not. Maybe > make it an explicit option instead of probing? I'm not sure it's worth using libc in liburing (x86(-64) and aarch64) just to activate the stack protector. Do you have other convincing use cases where libc is strictly needed on architectures that support liburing nolibc? I think using stack protector for liburing is just too overkill, but I may be wrong, please tell me a good reason for using it in liburing. I admit that nolibc brings problems. For example, the memset() issue on aarch64 recently (it's fixed). If you have similar problems, please tell. We probably should consider bringing back the "--nolibc" option in the "./configure" file? > I've included a downstream patch in the Fedora package that disables > nolibc for the time being. Thanks for maintaining the package. I appreciate it. -- Viro
