x86/idtentry: Error when CONFIG_HYPERV is set with LLVM_IAS=1

[dileks]

With @jcai19 diff from #1043 (comment) applied and CONFIG_HYPERV=m I see with Linux v5.8-rc4 and LLVM_IAS=1 (here: Debian/testing AMD64):

  clang-11 -Wp,-MMD,arch/x86/entry/.entry_64.o.d -nostdinc -isystem /usr/lib/llvm-11/lib/clang/11.0.0/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -D__KERNEL__ -Qunused-arguments -D__ASSEMBLY__ -fno-PIE -Werror=unknown-warning-option -m64 -Wa,-gdwarf-4 -gz=zlib -DCC_USING_FENTRY    -c -o arch/x86/entry/entry_64.o arch/x86/entry/entry_64.S
...
<instantiation>:9:6: error: expected absolute expression
 .if HYPERVISOR_REENLIGHTENMENT_VECTOR == 3
     ^
<instantiation>:1:1: note: while in macro instantiation
idtentry HYPERVISOR_REENLIGHTENMENT_VECTOR asm_sysvec_hyperv_reenlightenment sysvec_hyperv_reenlightenment has_error_code=0
^
./arch/x86/include/asm/idtentry.h:627:1: note: while in macro instantiation
idtentry_sysvec HYPERVISOR_REENLIGHTENMENT_VECTOR sysvec_hyperv_reenlightenment;
^
<instantiation>:9:6: error: expected absolute expression
 .if HYPERVISOR_STIMER0_VECTOR == 3
     ^
<instantiation>:1:1: note: while in macro instantiation
idtentry HYPERVISOR_STIMER0_VECTOR asm_sysvec_hyperv_stimer0 sysvec_hyperv_stimer0 has_error_code=0
^
./arch/x86/include/asm/idtentry.h:628:1: note: while in macro instantiation
idtentry_sysvec HYPERVISOR_STIMER0_VECTOR sysvec_hyperv_stimer0;
^
make[5]: *** [scripts/Makefile.build:361: arch/x86/entry/entry_64.o] Error 1
make[4]: *** [scripts/Makefile.build:497: arch/x86/entry] Error 2
make[3]: *** [Makefile:1762: arch/x86] Error 2

Check arch/x86/include/asm/idtentry.h:

Line #625: #if IS_ENABLED(CONFIG_HYPERV)
Line #626: DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR,	sysvec_hyperv_callback);
Line #627: DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_REENLIGHTENMENT_VECTOR,	sysvec_hyperv_reenlightenment);
Line #628: DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_STIMER0_VECTOR,	sysvec_hyperv_stimer0);
Line #629: #endif

1. Workaround: Use -no-integrated-as (see invalid reassignment of non-absolute variable 'pos' #1043 (comment))
2. Workaround: CONFIG_HYPERV=n

As @jcai19 points out this is a different issue to #1043.

[dileks]

Typos :-):

$ git diff arch/x86/include/asm/idtentry.h
diff --git a/arch/x86/include/asm/idtentry.h b/arch/x86/include/asm/idtentry.h
index 513eb2ccbdbf..a811f6c6cf15 100644
--- a/arch/x86/include/asm/idtentry.h
+++ b/arch/x86/include/asm/idtentry.h
@@ -624,8 +624,8 @@ DECLARE_IDTENTRY_SYSVEC(POSTED_INTR_NESTED_VECTOR,  sysvec_kvm_posted_intr_nested
 
 #if IS_ENABLED(CONFIG_HYPERV)
 DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_CALLBACK_VECTOR,    sysvec_hyperv_callback);
-DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_REENLIGHTENMENT_VECTOR,     sysvec_hyperv_reenlightenment);
-DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_STIMER0_VECTOR,     sysvec_hyperv_stimer0);
+DECLARE_IDTENTRY_SYSVEC(HYPERV_REENLIGHTENMENT_VECTOR, sysvec_hyperv_reenlightenment);
+DECLARE_IDTENTRY_SYSVEC(HYPERV_STIMER0_VECTOR, sysvec_hyperv_stimer0);
 #endif
 
 #if IS_ENABLED(CONFIG_ACRN_GUEST)

With that diff I am able to build with CONFIG_HYPERV=m:

  clang-11 -Wp,-MMD,arch/x86/entry/.entry_64.o.d -nostdinc -isystem /usr/lib/llvm-11/lib/clang/11.0.0/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -D__KERNEL__ -Qunused-arguments -D__ASSEMBLY__ -fno-PIE -Werror=unknown-warning-option -m64 -Wa,-gdwarf-4 -gz=zlib -DCC_USING_FENTRY    -c -o arch/x86/entry/entry_64.o arch/x86/entry/entry_64.S
   ./tools/objtool/objtool orc generate  --no-fp --retpoline --uaccess arch/x86/entry/entry_64.o
  if llvm-objdump-11 -h arch/x86/entry/entry_64.o | grep -q __ksymtab; then { echo "#include <linux/kernel.h>" ; echo "#include <asm/asm-prototypes.h>" ; clang-11 -E -Wp,-MMD,arch/x86/entry/.entry_64.o.d -nostdinc -isystem /usr/lib/llvm-11/lib/clang/11.0.0/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -D__KERNEL__ -Qunused-arguments -D__ASSEMBLY__ -fno-PIE -Werror=unknown-warning-option -m64 -Wa,-gdwarf-4 -gz=zlib -DCC_USING_FENTRY    arch/x86/entry/entry_64.S | grep "\<___EXPORT_SYMBOL\>" | sed 's/.*___EXPORT_SYMBOL[[:space:]]*\([a-zA-Z0-9_]*\)[[:space:]]*,.*/EXPORT_SYMBOL();/' ; } | clang-11 -E -D__GENKSYMS__ -Wp,-MMD,arch/x86/entry/.entry_64.o.d -nostdinc -isystem /usr/lib/llvm-11/lib/clang/11.0.0/include -I./arch/x86/include -I./arch/x86/include/generated  -I./include -I./arch/x86/include/uapi -I./arch/x86/include/generated/uapi -I./include/uapi -I./include/generated/uapi -include ./include/linux/kconfig.h -include ./include/linux/compiler_types.h -D__KERNEL__ -Qunused-arguments -Wall -Wundef -Werror=strict-prototypes -Wno-trigraphs -fno-strict-aliasing -fno-common -fshort-wchar -fno-PIE -Werror=implicit-function-declaration -Werror=implicit-int -Wno-format-security -std=gnu89 -Werror=unknown-warning-option -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -m64 -mno-80387 -mstack-alignment=8 -mtune=generic -mno-red-zone -mcmodel=kernel -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -fno-delete-null-pointer-checks -Wno-frame-address -Wno-address-of-packed-member -O2 -Wframe-larger-than=2048 -fstack-protector-strong -Wno-format-invalid-specifier -Wno-gnu -mno-global-merge -Wno-unused-const-variable -g -gdwarf-4 -gz=zlib -pg -mfentry -DCC_USING_FENTRY -Wdeclaration-after-statement -Wvla -Wno-pointer-sign -Wno-array-bounds -fno-strict-overflow -fno-merge-all-constants -fno-stack-check -Werror=date-time -Werror=incompatible-pointer-types -fmacro-prefix-map=./= -fcf-protection=none -Wno-initializer-overrides -Wno-format -Wno-sign-compare -Wno-format-zero-length -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare    -DKBUILD_MODFILE='"arch/x86/entry/entry_64"' -DKBUILD_BASENAME='"entry_64"' -DKBUILD_MODNAME='"entry_64"' -xc - | scripts/genksyms/genksyms    -r /dev/null > arch/x86/entry/.tmp_entry_64.ver; ld.lld-11 -m elf_x86_64  -z max-page-size=0x200000 --compress-debug-sections=zlib -r -o arch/x86/entry/.tmp_entry_64.o arch/x86/entry/entry_64.o -T arch/x86/entry/.tmp_entry_64.ver; mv -f arch/x86/entry/.tmp_entry_64.o arch/x86/entry/entry_64.o; rm -f arch/x86/entry/.tmp_entry_64.ver; fi

$ ll arch/x86/entry/entry_64.o
-rw-r--r-- 1 dileks dileks 84K 12. Jul 19:09 arch/x86/entry/entry_64.o

$ llvm-dwarfdump-11 arch/x86/entry/entry_64.o
arch/x86/entry/entry_64.o:      file format elf64-x86-64

.debug_info contents:
0x00000000: Compile Unit: length = 0x00000cc3, format = DWARF32, version = 0x0004, abbr_offset = 0x0000, addr_size = 0x08 (next unit at 0x00000cc7)

0x0000000b: DW_TAG_compile_unit
              DW_AT_stmt_list   (0x00000000)
              DW_AT_ranges      (0x00000000
                 [0x0000000000000000, 0x00000000000000b7)
                 [0x0000000000000000, 0x00000000000014ff)
                 [0x0000000000000000, 0x00000000000000d5)
                 [0x0000000000000000, 0x0000000000000013))
              DW_AT_name        ("arch/x86/entry/entry_64.S")
              DW_AT_comp_dir    ("/home/dileks/src/linux-kernel/git")
              DW_AT_producer    ("Debian clang version 11.0.0-++20200701093119+ffee8040534-1~exp1 ")
              DW_AT_language    (DW_LANG_Mips_Assembler)

[nathanchance]

Good catch! That should be sent upstream ASAP so that it can make it into 5.8 final.

$ rg --no-heading "HYPERVISOR_REENLIGHTENMENT_VECTOR|HYPERVISOR_STIMER0_VECTOR"
arch/x86/include/asm/idtentry.h:629:DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_REENLIGHTENMENT_VECTOR,  sysvec_hyperv_reenlightenment);
arch/x86/include/asm/idtentry.h:630:DECLARE_IDTENTRY_SYSVEC(HYPERVISOR_STIMER0_VECTOR,  sysvec_hyperv_stimer0);

$ rg --no-heading "HYPERV_REENLIGHTENMENT_VECTOR|HYPERV_STIMER0_VECTOR"
tools/arch/x86/include/asm/irq_vectors.h:103:#define HYPERV_REENLIGHTENMENT_VECTOR      0xee
tools/arch/x86/include/asm/irq_vectors.h:104:#define HYPERV_STIMER0_VECTOR              0xed
arch/x86/kernel/irq.c:147:      if (test_bit(HYPERV_REENLIGHTENMENT_VECTOR, system_vectors)) {
arch/x86/kernel/irq.c:154:      if (test_bit(HYPERV_STIMER0_VECTOR, system_vectors)) {
arch/x86/kernel/cpu/mshyperv.c:82:      add_interrupt_randomness(HYPERV_STIMER0_VECTOR, 0);
arch/x86/kernel/cpu/mshyperv.c:90:      *vector = HYPERV_STIMER0_VECTOR;
arch/x86/kernel/cpu/mshyperv.c:334:             alloc_intr_gate(HYPERV_REENLIGHTENMENT_VECTOR,
arch/x86/kernel/cpu/mshyperv.c:340:             alloc_intr_gate(HYPERV_STIMER0_VECTOR,
arch/x86/hyperv/hv_init.c:166:          .vector = HYPERV_REENLIGHTENMENT_VECTOR,
arch/x86/include/asm/irq_vectors.h:103:#define HYPERV_REENLIGHTENMENT_VECTOR    0xee
arch/x86/include/asm/irq_vectors.h:104:#define HYPERV_STIMER0_VECTOR            0xed

Feel free to stick Reviewed-by: Nathan Chancellor <natechancellor@gmail.com> on the patch.

[dileks]

I was able to build and boot on bare metal.

Thanks @nathanchance for the review.

[dileks]

Patch sent upstream.

[1] https://lore.kernel.org/patchwork/patch/1271438/
[2] https://lore.kernel.org/lkml/20200712231050.5147-1-sedat.dilek@gmail.com/

[dileks]

Submitted a v2.

[1] https://lore.kernel.org/patchwork/patch/1272393/
[2] https://lore.kernel.org/lkml/20200714111103.14591-1-sedat.dilek@gmail.com/

[dileks]

Submitted v3.

[1] https://lore.kernel.org/patchwork/patch/1273010/