that's a fundamental weakness of all the CFI annotations.
It is outright wrong to waste humans on this mechanic task: as it is
abundantly clear to GAS where we change a stack pointer and by how
much - it could emit magic annotations automatically just as much.
So if you care about it, please fix this in the tools space. The
entry_64.S impact of finegrained annotations is just too ugly for
things like this.
One limited exception is for basic stack frames where we do syscalls
or call into other C code. (i.e. the patch proposed here would have to
do that limited annotation)
But the per instruction annotations currently in that code are madness
and must either be cleaned up significantly via the use of GAS macros
(so that all stack pointer manipulations go via a single macro
invocation), or be completely auto-generated by GAS.
Ingo
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