On Tue, Apr 25, 2023 at 12:01:18AM +0000, SeongJae Park wrote: > Hello Sasha and Greg, > > > On Tue, 14 Mar 2023 08:43:16 -0400 Sasha Levin <sashal@xxxxxxxxxx> wrote: > > > From: David Gow <davidgow@xxxxxxxxxx> > > > > [ Upstream commit 8849818679478933dd1d9718741f4daa3f4e8b86 ] > > > > The kernel disables all SSE and similar FP/SIMD instructions on > > x86-based architectures (partly because we shouldn't be using floats in > > the kernel, and partly to avoid the need for stack alignment, see: > > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=53383 ) > > > > UML does not do the same thing, which isn't in itself a problem, but > > does add to the list of differences between UML and "normal" x86 builds. > > > > In addition, there was a crash bug with LLVM < 15 / rustc < 1.65 when > > building with SSE, so disabling it fixes rust builds with earlier > > compiler versions, see: > > https://github.com/Rust-for-Linux/linux/pull/881 > > > > Signed-off-by: David Gow <davidgow@xxxxxxxxxx> > > Reviewed-by: Sergio González Collado <sergio.collado@xxxxxxxxx> > > Signed-off-by: Richard Weinberger <richard@xxxxxx> > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > There is a followup fix of this patch that merged into the mainline by commit > a3046a618a28 ("um: Only disable SSE on clang to work around old GCC bugs"), but > it has not added to 6.1.y so far. Without it, compiling on some setup using an > old version of gcc fails, as the followup is also mentioning. I also confirmed > the issue can be reproduced on latest 6.1.y. > > Could you please add the followup fix to 6.1.y? I confirmed the commit can be > cleanly cherry-picked on latest 6.1.y, and fixes the issue as expected. Now queued up, thanks. greg k-h
