Re: [PATCH 5.7 v2] x86/crypto: aesni: Fix build with LLVM_IAS=1

[Sedat Dilek]

On Tue, Jun 23, 2020 at 8:44 PM Nick Desaulniers
<ndesaulniers@xxxxxxxxxx> wrote:
>
> On Mon, Jun 22, 2020 at 7:56 PM Sedat Dilek <sedat.dilek@xxxxxxxxx> wrote:
> >
> > When building with LLVM_IAS=1 means using Clang's Integrated Assembly (IAS)
> > from LLVM/Clang >= v10.0.1-rc1+ instead of GNU/as from GNU/binutils
> > I see the following breakage in Debian/testing AMD64:
> >
> > <instantiation>:15:74: error: too many positional arguments
> >  PRECOMPUTE 8*3+8(%rsp), %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7,
> >                                                                          ^
> >  arch/x86/crypto/aesni-intel_asm.S:1598:2: note: while in macro instantiation
> >  GCM_INIT %r9, 8*3 +8(%rsp), 8*3 +16(%rsp), 8*3 +24(%rsp)
> >  ^
> > <instantiation>:47:2: error: unknown use of instruction mnemonic without a size suffix
> >  GHASH_4_ENCRYPT_4_PARALLEL_dec %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, %xmm8, enc
> >  ^
> > arch/x86/crypto/aesni-intel_asm.S:1599:2: note: while in macro instantiation
> >  GCM_ENC_DEC dec
> >  ^
> > <instantiation>:15:74: error: too many positional arguments
> >  PRECOMPUTE 8*3+8(%rsp), %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7,
> >                                                                          ^
> > arch/x86/crypto/aesni-intel_asm.S:1686:2: note: while in macro instantiation
> >  GCM_INIT %r9, 8*3 +8(%rsp), 8*3 +16(%rsp), 8*3 +24(%rsp)
> >  ^
> > <instantiation>:47:2: error: unknown use of instruction mnemonic without a size suffix
> >  GHASH_4_ENCRYPT_4_PARALLEL_enc %xmm9, %xmm10, %xmm11, %xmm12, %xmm13, %xmm14, %xmm0, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7, %xmm8, enc
> >  ^
> > arch/x86/crypto/aesni-intel_asm.S:1687:2: note: while in macro instantiation
> >  GCM_ENC_DEC enc
> >
> > Craig Topper suggested me in ClangBuiltLinux issue #1050:
> >
> > > I think the "too many positional arguments" is because the parser isn't able
> > > to handle the trailing commas.
> > >
> > > The "unknown use of instruction mnemonic" is because the macro was named
> > > GHASH_4_ENCRYPT_4_PARALLEL_DEC but its being instantiated with
> > > GHASH_4_ENCRYPT_4_PARALLEL_dec I guess gas ignores case on the
> > > macro instantiation, but llvm doesn't.
> >
> > First, I removed the trailing comma in the PRECOMPUTE line.
> >
> > Second, I substituted:
> > 1. GHASH_4_ENCRYPT_4_PARALLEL_DEC -> GHASH_4_ENCRYPT_4_PARALLEL_dec
> > 2. GHASH_4_ENCRYPT_4_PARALLEL_ENC -> GHASH_4_ENCRYPT_4_PARALLEL_enc
> >
> > With these changes I was able to build with LLVM_IAS=1 and boot on bare metal.
> >
> > I confirmed that this works with Linux-kernel v5.7.5 final.
> >
> > NOTE: This patch is on top of Linux v5.7 final.
>
> Thanks for the note, still applies cleanly on top of linux-next today for me.
>
> >
> > Thanks to Craig and especially Nick for double-checking and his comments.
> >
> > Suggested-by: Craig Topper <craig.topper@xxxxxxxxx>
> > Suggested-by: Craig Topper <craig.topper@xxxxxxxxx>
> > Suggested-by: Nick Desaulniers ndesaulniers@xxxxxxxxxx
>
> ^ oh, may have missed <> around email addr.
>
> > Cc: "ClangBuiltLinux" <clang-built-linux@xxxxxxxxxxxxxxxx>
> > Link: https://github.com/ClangBuiltLinux/linux/issues/1050
> > Signed-off-by: Sedat Dilek <sedat.dilek@xxxxxxxxx>
>
> Following the same testing methodology from V1
> (https://lore.kernel.org/patchwork/comment/1456822/) I verified for
> GCC+GAS this is no functional change.
>
> $ wget https://lore.kernel.org/patchwork/patch/1261340/mbox/ -O sedat_v3.patch
> $ git am sedat_v3.patch
> $ make -j71 arch/x86/crypto/aesni-intel_asm.o
> $ llvm-objdump -dr arch/x86/crypto/aesni-intel_asm.o > postpatch_v3.txt
> $ diff -u <(cat prepatch.txt | tr -s ' ' | cut -d '    ' -f 2-) <(cat
> postpatch_v3.txt| tr -s ' ' | cut -d '   ' -f 2-) | less
> (no output)
>
> Reviewed-by: Nick Desaulniers <ndesaulniers@xxxxxxxxxx>
>

Thanks a lot for your feedback.

I have sent a v4 with corrected email-address and your Reviewed-by.

- Sedat -

[1] https://lore.kernel.org/patchwork/patch/1263102/
[2] https://lore.kernel.org/lkml/20200624051538.5355-1-sedat.dilek@xxxxxxxxx/

> > ---
> >  arch/x86/crypto/aesni-intel_asm.S | 6 +++---
> >  1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S
> > index cad6e1bfa7d5..c216de287742 100644
> > --- a/arch/x86/crypto/aesni-intel_asm.S
> > +++ b/arch/x86/crypto/aesni-intel_asm.S
> > @@ -266,7 +266,7 @@ ALL_F:      .octa 0xffffffffffffffffffffffffffffffff
> >         PSHUFB_XMM %xmm2, %xmm0
> >         movdqu %xmm0, CurCount(%arg2) # ctx_data.current_counter = iv
> >
> > -       PRECOMPUTE \SUBKEY, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7,
> > +       PRECOMPUTE \SUBKEY, %xmm1, %xmm2, %xmm3, %xmm4, %xmm5, %xmm6, %xmm7
> >         movdqu HashKey(%arg2), %xmm13
> >
> >         CALC_AAD_HASH %xmm13, \AAD, \AADLEN, %xmm0, %xmm1, %xmm2, %xmm3, \
> > @@ -978,7 +978,7 @@ _initial_blocks_done\@:
> >  * arg1, %arg3, %arg4 are used as pointers only, not modified
> >  * %r11 is the data offset value
> >  */
> > -.macro GHASH_4_ENCRYPT_4_PARALLEL_ENC TMP1 TMP2 TMP3 TMP4 TMP5 \
> > +.macro GHASH_4_ENCRYPT_4_PARALLEL_enc TMP1 TMP2 TMP3 TMP4 TMP5 \
> >  TMP6 XMM0 XMM1 XMM2 XMM3 XMM4 XMM5 XMM6 XMM7 XMM8 operation
> >
> >         movdqa    \XMM1, \XMM5
> > @@ -1186,7 +1186,7 @@ aes_loop_par_enc_done\@:
> >  * arg1, %arg3, %arg4 are used as pointers only, not modified
> >  * %r11 is the data offset value
> >  */
> > -.macro GHASH_4_ENCRYPT_4_PARALLEL_DEC TMP1 TMP2 TMP3 TMP4 TMP5 \
> > +.macro GHASH_4_ENCRYPT_4_PARALLEL_dec TMP1 TMP2 TMP3 TMP4 TMP5 \
> >  TMP6 XMM0 XMM1 XMM2 XMM3 XMM4 XMM5 XMM6 XMM7 XMM8 operation
> >
> >         movdqa    \XMM1, \XMM5
> > --
>
> --
> Thanks,
> ~Nick Desaulniers