On Mon, Jun 22, 2020 at 8:50 AM 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 === I think from here to... > > 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. Yep, see also: commit 6f5459da2b87 ("arm64: alternative: fix build with clang integrated assembler") https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=6f5459da2b8736720afdbd67c4bd2d1edba7d0e3 > > First, I removed the trailing comma in the PRECOMPUTE line. > > Second, I substituted: > 1. GCM_ENC_DEC dec -> GCM_ENC_DEC DEC > 2. GCM_ENC_DEC enc -> GCM_ENC_DEC ENC > > With these changes I was able to build with LLVM_IAS=1 and boot on bare metal. > > As llvm-toolchain I used v10.0.1-rc1+ and v11.0.0-git pre-releases: > 1. release/10.x Git: 2dc664d578f0e9c8ea5975eed745e322fa77bffe > 2. master Git: 8da5b9083691b557f50f72ab099598bb291aec5f (default) > > Just for the sake of completeness: > 1. CONFIG_DEBUG_INFO_DWARF4=y > 2. OBJDUMP=llvm-objdump (passed to my make-line) > > Please have a look into "llvm.rst" kernel-doc for further informations and > how to pass LLVM kbuild-options to your make-line. > > I confirmed that this works with Linux-kernel v5.7.3 and v5.7.5 final. > > NOTE: This patch is on top of Linux v5.7 final. > > Thanks to Craig and the folks from the ClangBuiltLinux project. ===...here can be cut out from the commit message. > > Cc: Craig Topper <craig.topper@xxxxxxxxx> > Cc: Craig Topper <craig.topper@xxxxxxxxx> I'd pick one or the other email addresses, and just use that one. Craig seems to commit to LLVM with craig.topper@xxxxxxxxx, so I recommend that one. > Cc: Nick Desaulniers ndesaulniers@xxxxxxxxxx Thanks for the explicit CC, though I do monitor the below list actively. > Cc: "ClangBuiltLinux" <clang-built-linux@xxxxxxxxxxxxxxxx> > Link: https://github.com/ClangBuiltLinux/linux/issues/1050 > Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/Documentation/kbuild/llvm.rst ^ probably don't need that link either. > > --- > arch/x86/crypto/aesni-intel_asm.S | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/arch/x86/crypto/aesni-intel_asm.S b/arch/x86/crypto/aesni-intel_asm.S > index cad6e1bfa7d5..983eb2eec51a 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, \ There's a comparison on L386 386 .ifc \operation, dec Also, L407, L393, L672, L808, L841, L935, L941, L947, If we change the `\operation` macro parameter to be `DEC` instead of `dec`, does this comparison still hold true? I would expect not if LLVM's integrated assembler is case sensitive? Otherwise we're probably missing instructions for the case of `DEC`. In that case, that should probably get fixed. Interesting, looks like GAS *is* case sensitive for `.ifc` directives? ``` $ cat foo.s .macro foo op .ifc \op, dec subq r8, r9 .else addq $0, r8 .endif .endm foo DEC $ clang foo.s -c $ llvm-objdump -d foo.o ... 0: 48 83 04 25 00 00 00 00 00 addq $0, 0 $ as foo.s -c $ llvm-objdump -d foo.o ... 0: 48 83 04 25 00 00 00 00 00 addq $0, 0 ``` In that case, it seems that this patch probably breaks the DEC case for both toolchains. Just to triple check, forgetting LLVM for a minute, let's compare the disassembly before and after. $ make -j71 defconfig $ make -j71 menuconfig <enable CRYPTO_AES_NI_INTEL> $ make -j71 arch/x86/crypto/aesni-intel_asm.o $ llvm-objdump -dr arch/x86/crypto/aesni-intel_asm.o > prepatch.txt <apply your patch> $ make -j71 arch/x86/crypto/aesni-intel_asm.o $ llvm-objdump -dr arch/x86/crypto/aesni-intel_asm.o > postpatch.txt $ diff -u <(cat prepatch.txt | tr -s ' ' | cut -d ' ' -f 2-) <(cat postpatch.txt| tr -s ' ' | cut -d ' ' -f 2-) | less It's not the easiest to tell, since I should have left off `-r` for relocations from objdump, but you can clearly see cases of different disassembly. Even the address of labels changes due to missing instructions. In that case, it's probably a smaller change to just renamed the macros GHASH_4_ENCRYPT_4_PARALLEL_ENC GHASH_4_ENCRYPT_4_PARALLEL_DEC to GHASH_4_ENCRYPT_4_PARALLEL_enc GHASH_4_ENCRYPT_4_PARALLEL_dec respectively, though using ALL CAPS is likely more consistent at the cost of more lines changed. Also, sorry I didn't catch this on the earlier thread; my mistake. > @@ -1596,7 +1596,7 @@ SYM_FUNC_START(aesni_gcm_dec) > FUNC_SAVE > > GCM_INIT %arg6, arg7, arg8, arg9 > - GCM_ENC_DEC dec > + GCM_ENC_DEC DEC > GCM_COMPLETE arg10, arg11 > FUNC_RESTORE > ret > @@ -1684,7 +1684,7 @@ SYM_FUNC_START(aesni_gcm_enc) > FUNC_SAVE > > GCM_INIT %arg6, arg7, arg8, arg9 > - GCM_ENC_DEC enc > + GCM_ENC_DEC ENC > > GCM_COMPLETE arg10, arg11 > FUNC_RESTORE > @@ -1719,7 +1719,7 @@ SYM_FUNC_END(aesni_gcm_init) > */ > SYM_FUNC_START(aesni_gcm_enc_update) > FUNC_SAVE > - GCM_ENC_DEC enc > + GCM_ENC_DEC ENC > FUNC_RESTORE > ret > SYM_FUNC_END(aesni_gcm_enc_update) > @@ -1734,7 +1734,7 @@ SYM_FUNC_END(aesni_gcm_enc_update) > */ > SYM_FUNC_START(aesni_gcm_dec_update) > FUNC_SAVE > - GCM_ENC_DEC dec > + GCM_ENC_DEC DEC > FUNC_RESTORE > ret > SYM_FUNC_END(aesni_gcm_dec_update) > -- -- Thanks, ~Nick Desaulniers