On Sun, Jan 15, 2023 at 09:46:36PM -0700, Nathan Chancellor wrote: > Hi Greg and Sasha, > > Clang 16 (current main, next major release) errors when offsetof() has a > type defintion in it, in response to language in newer C standards > stating it is undefined behavior. > > https://github.com/llvm/llvm-project/commit/e327b52766ed497e4779f4e652b9ad237dfda8e6 > https://reviews.llvm.org/D133574 > > While this might be eventually demoted to just a warning, the kernel has > already cleaned up places that had this construct, so we can apply them > to the stable trees and avoid the issue altogether. > > Please find attached mbox files for all supported stable trees, which > fix up the relevant instances for each tree using the upstream commits: > > 55228db2697c ("x86/fpu: Use _Alignof to avoid undefined behavior in TYPE_ALIGN") > 09794a5a6c34 ("tracing: Use alignof__(struct {type b;}) instead of offsetof()") > > The fpu commit uses _Alignof, which as far as I can tell was only > supported in GCC 4.7.0+. This is not a problem for mainline due to > requiring GCC 5.1.0+ but it could be relevant for old trees like 4.14, > which have an older minimum supported version. I hope people are not > using ancient compilers like that but I suppose if they are using 4.14, > they might just be stuck with old software... > > If there are any issues or comments, please let me know. Now queued up, thanks. greg k-h
