Messages in this thread | | | Date | Mon, 02 Mar 2020 22:47:18 +0530 | From | "Naveen N. Rao" <> | Subject | Re: eh_frame confusion |
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Segher Boessenkool wrote: > On Mon, Mar 02, 2020 at 11:56:05AM +0100, Rasmus Villemoes wrote: >> I'm building a ppc32 kernel, and noticed that after upgrading from gcc-7 >> to gcc-8 all object files now end up having .eh_frame section. > > Since GCC 8, we enable -fasynchronous-unwind-tables by default for > PowerPC. See https://gcc.gnu.org/r259298 . > >> For >> vmlinux, that's not a problem, because they all get discarded in >> arch/powerpc/kernel/vmlinux.lds.S . However, they stick around in >> modules, which doesn't seem to be useful - given that everything worked >> just fine with gcc-7, and I don't see anything in the module loader that >> handles .eh_frame. > > It is useful for debugging. Not many people debug the kernel like this, > of course.
I'm trying to understand if we need that. Other architectures seems to pass -fasynchronous-unwind-tables only for the vdso, but disable it for the kernel build. I suppose we can do the same.
If using -fno-asynchronous-unwind-tables, would crash/perf have problems?
- Naveen
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