On Thu, May 12, 2022 at 07:24:25PM +0200, Heiko Carstens wrote: > From fe4fb0b014378d84ae517deaea338577b2ea6ae0 Mon Sep 17 00:00:00 2001 > From: Heiko Carstens <hca@xxxxxxxxxxxxx> > Date: Sat, 7 May 2022 15:00:40 +0200 > Subject: [PATCH 3/7] s390/entry: workaround llvm's IAS limitations > > llvm's integrated assembler cannot handle immediate values which are > calculated with two local labels: > > <instantiation>:3:13: error: invalid operand for instruction > clgfi %r14,.Lsie_done - .Lsie_gmap > > Workaround this by adding clang specific code which reads the specific > value from memory. Since this code is within the hot paths of the kernel > and adds an additional memory reference, keep the original code, and add > ifdef'ed code. > > Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx> > --- > arch/s390/kernel/entry.S | 14 ++++++++++++-- > 1 file changed, 12 insertions(+), 2 deletions(-) > > diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S > index a6b45eaa3450..f2f30bfba1e9 100644 > --- a/arch/s390/kernel/entry.S > +++ b/arch/s390/kernel/entry.S > @@ -172,9 +172,19 @@ _LPP_OFFSET = __LC_LPP > lgr %r14,\reg > larl %r13,\start > slgr %r14,%r13 > - lghi %r13,\end - \start > - clgr %r14,%r13 > +#ifdef CONFIG_AS_IS_LLVM > + clgfrl %r14,.Lrange_size\@ > +#else > + clgfi %r14,\end - \start > +#endif > jhe \outside_label > +#ifdef CONFIG_CC_IS_CLANG > + .section .rodata, "a" > + .align 4 > +.Lrange_size\@: > + .long \end - \start Isn't the machine check handler refers to this memory before checking unrecoverable storage errors (with CHKSTG macro) as result of this change? > + .previous > +#endif > .endm > > .macro SIEEXIT > -- > 2.32.0
