On Fri, Feb 5, 2021 at 8:21 PM Yonghong Song wrote: > > > > On 2/5/21 11:15 AM, Sedat Dilek wrote: > > On Fri, Feb 5, 2021 at 8:10 PM Yonghong Song wrote: > >> > >> > >> > >> On 2/5/21 11:06 AM, Sedat Dilek wrote: > >>> On Fri, Feb 5, 2021 at 7:53 PM Sedat Dilek wrote: > >>>> > >>>> On Fri, Feb 5, 2021 at 6:48 PM Sedat Dilek wrote: > >>>>> > >>>>> On Fri, Feb 5, 2021 at 4:28 PM Arnaldo Carvalho de Melo > >>>>> 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 wrote: > >>>>>>>> > >>>>>>>> On Fri, Feb 5, 2021 at 3:37 PM Sedat Dilek 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. > With the attached diff I get again: + 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 [115] INT DW_ATE_unsigned_1 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 Can someone please look at the attached diff? Thanks. - Sedat - > > > > 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 - > >