[PATCH 2/3] nptl: Do not always assume set_robust_list availability (BZ 33225)

[Adhemerval Zanella Netto]

On 30/07/25 03:41, Andreas Schwab wrote:
> On Jul 29 2025, Florian Weimer wrote:
> 
>> I'm not sure this is the right direction.  Is qemu-user compatibility
>> that important to users?
> 
> For example, openSUSE Tumbleweed for RISC-V is built completely with
> qemu user-space emulation (we don't have this issue right now since our
> glibc is built with the default minimum kernel that still enables the
> runtime check).
> 
> FWIW, the other big problem for qemu user-space emulation is posix_spawn
> because the emulation does not implement a true CLONE_VFORK (it emulates
> it with fork).  This breaks situations where there are errors in the
> child process until and including execve; that failure cannot be
> communicated back to the parent process.
> 

Is there any technical reason to not proper implement CLONE_VFORK? It
should be feasible to add a workaround to user fork/execve plus pipe
communication (like old implementation) if clone (CLONE_VFORK) fails,
but this really adds some extra maintainability.