https://gcc.gnu.org/bugzilla/show_bug.cgi?id=119279
--- Comment #8 from peterz at infradead dot org --- On Fri, Mar 14, 2025 at 08:44:19AM +0000, torva...@linux-foundation.org wrote: > Now, I agree that the kernel could likely solve issues by just "don't check so > much, then". But our build-time object file checking does actually find real > issues, because we tend to have various constraints that normal programs don't > have (and we do various rewriting of the object files due to them, which is > another big reason for checking: making sure the rewriting tool understands > the > code it rewrites!). There is the additional constraint that as long as the frame pointer unwinder does not have to guess, it is assumed to be 100% correct. By having calls before frame setup, we get functions missing from the unwind. This means that unwind can no longer be relied upon to determine live-ness of a function. Live Patch in particular relies on this; it needs to determine if a function is in-use. Notably replacing functions that are in-use is a very bad idea.
