On Wed, Nov 07, 2012 at 10:47:53AM +0100, Vineet Gupta wrote: > +; When we land here, pt_regs have already been updated in-place correctly > +; A pointer to them is also passed by kernel_execve, we just need to make sure > +; that SP is set to point to them. > +ARC_ENTRY ret_from_kernel_execve > + ; Force SP to "normal" pt_regs just populated. > + b.d ret_from_system_call > + mov sp, r0 won't that splatter crap into regs->r0? IOW, why not branch to ret_from_exception here? > +ARC_EXIT ret_from_kernel_execve Another thing: why not fold that branch to ret_from_exception into the end of ret_from_kernel_thread() (instead of calling sys_exit()), select GENERIC_KERNEL_EXECVE and lose __ARCH_WANT_KERNEL_EXECVE. Actually, now that I look at your ret_from_kernel_thread... How the hell will it cope with kernel_thread() payload trying to return? AFAICS, this j.d [r1] will lose the return address, won't it? And while we are at it, I would suggest passing callback and its argument via callee-saved registers - makes for simpler life in ret_from_kernel_thread(), since switch_to() itself will take care of loading those... -- To unsubscribe from this list: send the line "unsubscribe linux-arch" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html