Re: [PATCH for review] [127/145] i386: movekernel_thread_helper into entry.S

[Jan Beulich]

>And add proper CFI annotation to it which was previously
>impossible. This prevents "stuck" messages by the dwarf2 unwinder
>when reaching the top of a kernel stack.

>+ENTRY(kernel_thread_helper)
>+	CFI_STARTPROC
>+	movl %edx,%eax
>+	CFI_REGISTER edx,eax

This is pointless, as %eax will be clobbered by the callee of the
subsequent call.

>+	push %edx
>+	CFI_ADJUST_CFA_OFFSET 4
>+	CFI_REL_OFFSET edx,0

This likewise is pointless, as the argument is owned by the callee.

>+	call *%ebx
>+	push %eax
>+	CFI_ADJUST_CFA_OFFSET 4
>+	CFI_REL_OFFSET eax,0

And this too - the value now in %eax has no relation with the
value known by the caller of this routine (which doesn't expect
any return from here anyway).

>+	call do_exit
>+	CFI_ENDPROC
>+ENDPROC(kernel_thread_helper)

Jan
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