Messages in this thread | | | Date | Tue, 26 Jan 2021 09:46:51 -0600 | From | Josh Poimboeuf <> | Subject | Re: [PATCH RFC] gcc-plugins: Handle GCC version mismatch for OOT modules |
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On Tue, Jan 26, 2021 at 04:15:37PM +0100, Peter Zijlstra wrote: > On Tue, Jan 26, 2021 at 08:51:55AM -0600, Josh Poimboeuf wrote: > > User space mixes compiler versions all the time. The C ABI is stable. > > > > What specifically is the harder issue you're referring to? > > I don't think the C ABI captures nearly enough. Imagine trying to mix a > compiler with and without asm-goto support (ok, we fail to build without > by now, but just imagine). > > No C ABI violated, but having that GCC extention vs not having it > radically changes the kernel ABI. > > I think I'm with Greg here, just don't do it.
Ok, thank you for an actual example. asm goto is a good one.
But it's not a cut-and-dry issue. Otherwise how could modversions possibly work?
So yes, we should enforce GCC versions, but I still haven't seen a reason it should be more than just "same compiler and *major* version".
-- Josh
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