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    SubjectRe: ERROR: INT DW_ATE_unsigned_1 Error emitting BTF type
    On Fri, Feb 5, 2021 at 8:21 PM Yonghong Song <yhs@fb.com> wrote:
    >
    >
    >
    > 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.
    >

    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 -
    > >
    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..f47de1ecd21e 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) {
    + ; /* ignored for now */
    } else if (bt->float_type) {
    fprintf(stderr, "float_type is not supported\n");
    return -1;
    \
     
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      Last update: 2021-02-05 20:49    [W:2.507 / U:0.196 seconds]
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