Messages in this thread Patch in this message | | | Subject | Re: ERROR: INT DW_ATE_unsigned_1 Error emitting BTF type | From | Yonghong Song <> | Date | Fri, 5 Feb 2021 11:20:50 -0800 |
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On 2/5/21 11:15 AM, Sedat Dilek wrote: > On Fri, Feb 5, 2021 at 8:10 PM Yonghong Song <yhs@fb.com> wrote: >> >> >> >> On 2/5/21 11:06 AM, Sedat Dilek wrote: >>> On Fri, Feb 5, 2021 at 7:53 PM Sedat Dilek <sedat.dilek@gmail.com> wrote: >>>> >>>> On Fri, Feb 5, 2021 at 6:48 PM Sedat Dilek <sedat.dilek@gmail.com> wrote: >>>>> >>>>> On Fri, Feb 5, 2021 at 4:28 PM Arnaldo Carvalho de Melo >>>>> <arnaldo.melo@gmail.com> wrote: >>>>>> >>>>>> Em Fri, Feb 05, 2021 at 04:23:59PM +0100, Sedat Dilek escreveu: >>>>>>> On Fri, Feb 5, 2021 at 3:41 PM Sedat Dilek <sedat.dilek@gmail.com> wrote: >>>>>>>> >>>>>>>> On Fri, Feb 5, 2021 at 3:37 PM Sedat Dilek <sedat.dilek@gmail.com> wrote: >>>>>>>>> >>>>>>>>> Hi, >>>>>>>>> >>>>>>>>> when building with pahole v1.20 and binutils v2.35.2 plus Clang >>>>>>>>> v12.0.0-rc1 and DWARF-v5 I see: >>>>>>>>> ... >>>>>>>>> + info BTF .btf.vmlinux.bin.o >>>>>>>>> + [ != silent_ ] >>>>>>>>> + printf %-7s %s\n BTF .btf.vmlinux.bin.o >>>>>>>>> BTF .btf.vmlinux.bin.o >>>>>>>>> + LLVM_OBJCOPY=/opt/binutils/bin/objcopy /opt/pahole/bin/pahole -J >>>>>>>>> .tmp_vmlinux.btf >>>>>>>>> [115] INT DW_ATE_unsigned_1 Error emitting BTF type >>>>>>>>> Encountered error while encoding BTF. >>>>>>>> >>>>>>>> Grepping the pahole sources: >>>>>>>> >>>>>>>> $ git grep DW_ATE >>>>>>>> dwarf_loader.c: bt->is_bool = encoding == DW_ATE_boolean; >>>>>>>> dwarf_loader.c: bt->is_signed = encoding == DW_ATE_signed; >>>>>>>> >>>>>>>> Missing DW_ATE_unsigned encoding? >>>>>>>> >>>>>>> >>>>>>> Checked the LLVM sources: >>>>>>> >>>>>>> clang/lib/CodeGen/CGDebugInfo.cpp: Encoding = >>>>>>> llvm::dwarf::DW_ATE_unsigned_char; >>>>>>> clang/lib/CodeGen/CGDebugInfo.cpp: Encoding = llvm::dwarf::DW_ATE_unsigned; >>>>>>> clang/lib/CodeGen/CGDebugInfo.cpp: Encoding = >>>>>>> llvm::dwarf::DW_ATE_unsigned_fixed; >>>>>>> clang/lib/CodeGen/CGDebugInfo.cpp: >>>>>>> ? llvm::dwarf::DW_ATE_unsigned >>>>>>> ... >>>>>>> lld/test/wasm/debuginfo.test:CHECK-NEXT: DW_AT_encoding >>>>>>> (DW_ATE_unsigned) >>>>>>> >>>>>>> So, I will switch from GNU ld.bfd v2.35.2 to LLD-12. >>>>>> >>>>>> Thanks for the research, probably your conclusion is correct, can you go >>>>>> the next step and add that part and check if the end result is the >>>>>> expected one? >>>>>> >>>>> >>>>> Still building... >>>>> >>>>> Can you give me a hand on what has to be changed in dwarves/pahole? >>>>> >>>>> I guess switching from ld.bfd to ld.lld will show the same ERROR. >>>>> >>>> >>>> This builds successfully - untested: >>>> >>>> $ git diff >>>> diff --git a/btf_loader.c b/btf_loader.c >>>> index ec286f413f36..a39edd3362db 100644 >>>> --- a/btf_loader.c >>>> +++ b/btf_loader.c >>>> @@ -107,6 +107,7 @@ static struct base_type *base_type__new(strings_t >>>> name, uint32_t attrs, >>>> bt->bit_size = size; >>>> bt->is_signed = attrs & BTF_INT_SIGNED; >>>> bt->is_bool = attrs & BTF_INT_BOOL; >>>> + bt->is_unsigned = attrs & BTF_INT_UNSIGNED; >>>> bt->name_has_encoding = false; >>>> bt->float_type = float_type; >>>> } >>>> diff --git a/ctf.h b/ctf.h >>>> index 25b79892bde3..9e47c3c74677 100644 >>>> --- a/ctf.h >>>> +++ b/ctf.h >>>> @@ -100,6 +100,7 @@ struct ctf_full_type { >>>> #define CTF_TYPE_INT_CHAR 0x2 >>>> #define CTF_TYPE_INT_BOOL 0x4 >>>> #define CTF_TYPE_INT_VARARGS 0x8 >>>> +#define CTF_TYPE_INT_UNSIGNED 0x16 >>>> >>>> #define CTF_TYPE_FP_ATTRS(VAL) ((VAL) >> 24) >>>> #define CTF_TYPE_FP_OFFSET(VAL) (((VAL) >> 16) & 0xff) >>>> diff --git a/dwarf_loader.c b/dwarf_loader.c >>>> index b73d7867e1e6..79d40f183c24 100644 >>>> --- a/dwarf_loader.c >>>> +++ b/dwarf_loader.c >>>> @@ -473,6 +473,7 @@ static struct base_type *base_type__new(Dwarf_Die >>>> *die, struct cu *cu) >>>> bt->is_bool = encoding == DW_ATE_boolean; >>>> bt->is_signed = encoding == DW_ATE_signed; >>>> bt->is_varargs = false; >>>> + bt->is_unsigned = encoding == DW_ATE_unsigned; >>>> bt->name_has_encoding = true; >>>> } >>>> >>>> diff --git a/dwarves.h b/dwarves.h >>>> index 98caf1abc54d..edf32d2e6f80 100644 >>>> --- a/dwarves.h >>>> +++ b/dwarves.h >>>> @@ -1261,6 +1261,7 @@ struct base_type { >>>> uint8_t is_signed:1; >>>> uint8_t is_bool:1; >>>> uint8_t is_varargs:1; >>>> + uint8_t is_unsigned:1; >>>> uint8_t float_type:4; >>>> }; >>>> >>>> diff --git a/lib/bpf b/lib/bpf >>>> --- a/lib/bpf >>>> +++ b/lib/bpf >>>> @@ -1 +1 @@ >>>> -Subproject commit 5af3d86b5a2c5fecdc3ab83822d083edd32b4396 >>>> +Subproject commit 5af3d86b5a2c5fecdc3ab83822d083edd32b4396-dirty >>>> diff --git a/libbtf.c b/libbtf.c >>>> index 9f7628304495..a0661a7bbed9 100644 >>>> --- a/libbtf.c >>>> +++ b/libbtf.c >>>> @@ -247,6 +247,8 @@ static const char * >>>> btf_elf__int_encoding_str(uint8_t encoding) >>>> return "CHAR"; >>>> else if (encoding == BTF_INT_BOOL) >>>> return "BOOL"; >>>> + else if (encoding == BTF_INT_UNSIGNED) >>>> + return "UNSIGNED"; >>>> else >>>> return "UNKN"; >>>> } >>>> @@ -379,6 +381,8 @@ int32_t btf_elf__add_base_type(struct btf_elf >>>> *btfe, const struct base_type *bt, >>>> encoding = BTF_INT_SIGNED; >>>> } else if (bt->is_bool) { >>>> encoding = BTF_INT_BOOL; >>>> + } else if (bt->is_unsigned) { >>>> + encoding = BTF_INT_UNSIGNED; >>>> } else if (bt->float_type) { >>>> fprintf(stderr, "float_type is not supported\n"); >>>> return -1; >>>> >>>> Additionally - I cannot see it with `git diff`: >>>> >>>> [ lib/bpf/include/uapi/linux/btf.h ] >>>> >>>> /* Attributes stored in the BTF_INT_ENCODING */ >>>> #define BTF_INT_SIGNED (1 << 0) >>>> #define BTF_INT_CHAR (1 << 1) >>>> #define BTF_INT_BOOL (1 << 2) >>>> #define BTF_INT_UNSIGNED (1 << 3) >>>> >>>> Comments? >>>> >>> >>> Hmmm... >>> >>> + info BTF .btf.vmlinux.bin.o >>> + [ != silent_ ] >>> + printf %-7s %s\n BTF .btf.vmlinux.bin.o >>> BTF .btf.vmlinux.bin.o >>> + LLVM_OBJCOPY=llvm-objcopy /opt/pahole/bin/pahole -J .tmp_vmlinux.btf >>> [2] INT long unsigned int Error emitting BTF type >>> Encountered error while encoding BTF. >>> + llvm-objcopy --only-section=.BTF --set-section-flags >>> .BTF=alloc,readonly --strip-all .tmp_vmlinux.btf .btf.vmlinux.bin.o >>> ... >>> + info BTFIDS vmlinux >>> + [ != silent_ ] >>> + printf %-7s %s\n BTFIDS vmlinux >>> BTFIDS vmlinux >>> + ./tools/bpf/resolve_btfids/resolve_btfids vmlinux >>> FAILED: load BTF from vmlinux: Invalid argument >>> + on_exit >>> + [ 255 -ne 0 ] >>> + cleanup >>> + rm -f .btf.vmlinux.bin.o >>> + rm -f .tmp_System.map >>> + rm -f .tmp_vmlinux.btf .tmp_vmlinux.kallsyms1 >>> .tmp_vmlinux.kallsyms1.S .tmp_vmlinux.kallsyms1.o >>> .tmp_vmlinux.kallsyms2 .tmp_vmlinux.kallsyms2.S .tmp_vmlinux.kallsyms >>> 2.o >>> + rm -f System.map >>> + rm -f vmlinux >>> + rm -f vmlinux.o >>> make[3]: *** [Makefile:1166: vmlinux] Error 255 >>> >>> Grepping through linux.git/tools I guess some BTF tools/libs need to >>> know what BTF_INT_UNSIGNED is? >> >> BTF_INT_UNSIGNED needs kernel support. Maybe to teach pahole to >> ignore this for now until kernel infrastructure is ready. >> Not sure whether this information will be useful or not >> for BTF. This needs to be discussed separately. >> > > [ CC Fangrui ] > > How can I teach pahole to ignore BTF_INT_UNSIGNED?
i mean for the following:
@@ -379,6 +381,8 @@ int32_t btf_elf__add_base_type(struct btf_elf *btfe, const struct base_type *bt, encoding = BTF_INT_SIGNED; } else if (bt->is_bool) { encoding = BTF_INT_BOOL; + } else if (bt->is_unsigned) { + encoding = BTF_INT_UNSIGNED; } else if (bt->float_type) { fprintf(stderr, "float_type is not supported\n"); return -1;
You can do
@@ -379,6 +381,8 @@ int32_t btf_elf__add_base_type(struct btf_elf *btfe, const struct base_type *bt, encoding = BTF_INT_SIGNED; } else if (bt->is_bool) { encoding = BTF_INT_BOOL; + } else if (bt->is_unsigned) { + ; /* ignored for now */ } else if (bt->float_type) { fprintf(stderr, "float_type is not supported\n"); return -1; The default encoding is 0 which indicates an unsigned int.
> > Another tryout might be to use "-fbinutils-version=..." which is > available for LLVM-12 according to Fangrui? > Fangrui, which binutils versions can I pass and how?
> > Thanks. > > - Sedat - >
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