Re: [PATCH] unicore32 fix: remove arch-specific futex support

[Arnd Bergmann]

On Wednesday 30 March 2011, Thomas Gleixner wrote:
> The problem is that you need cmpxchg in user space as well.
> 
> ARM does this with some syscall magic for machines which do not have
> cmpxchg.

Ah, right. I wonder how sh does it.

I also remember that the original unicore32 ABI had support for a cmpxchg
system call, but that was removed with the move to the generic syscall
table.

It is of course possible to add it back using the __NR_arch_specific_syscall
entry point.

	Arnd
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