| Message ID | 20211123045612.1387544-1-yhs@fb.com (mailing list archive) |
|---|---|
| Headers | show |
| Series | btf: support btf_type_tag attribute | expand |
On Mon, Nov 22, 2021 at 8:56 PM Yonghong Song <yhs@fb.com> wrote: > > btf_type_tag is a new llvm type attribute which is used similar > to kernel __user/__rcu attributes. The format of btf_type_tag looks like > __attribute__((btf_type_tag("tag1"))) > For the case where the attribute applied to a pointee like > #define __tag1 __attribute__((btf_type_tag("tag1"))) > #define __tag2 __attribute__((btf_type_tag("tag2"))) > int __tag1 * __tag1 __tag2 *g; > the information will be encoded in dwarf. > > In BTF, the attribute is encoded as a new kind > BTF_KIND_TYPE_TAG and latest bpf-next supports it. > > The patch added support in pahole, specifically > converts llvm dwarf btf_type_tag attributes to > BTF types. Please see individual patches for details. > > Changelog: > v1 -> v2: > - reorg an if condition to reduce nesting level. > - add more comments to explain how to chain type tag types. > > Yonghong Song (4): > libbpf: sync with latest libbpf repo > dutil: move DW_TAG_LLVM_annotation definition to dutil.h > dwarf_loader: support btf_type_tag attribute > btf_encoder: support btf_type_tag attribute > I thought that v1 was already applied, but either way LGTM. I'm not super familiar with the DWARF loader parts, so I mostly just read it very superficially :) Acked-by: Andrii Nakryiko <andrii@kernel.org> > btf_encoder.c | 7 +++ > dutil.h | 4 ++ > dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- > dwarves.h | 38 +++++++++++++- > lib/bpf | 2 +- > pahole.c | 8 +++ > 6 files changed, 190 insertions(+), 9 deletions(-) > > -- > 2.30.2 >
Em Tue, Nov 23, 2021 at 10:32:18AM -0800, Andrii Nakryiko escreveu: > On Mon, Nov 22, 2021 at 8:56 PM Yonghong Song <yhs@fb.com> wrote: > > > > btf_type_tag is a new llvm type attribute which is used similar > > to kernel __user/__rcu attributes. The format of btf_type_tag looks like > > __attribute__((btf_type_tag("tag1"))) > > For the case where the attribute applied to a pointee like > > #define __tag1 __attribute__((btf_type_tag("tag1"))) > > #define __tag2 __attribute__((btf_type_tag("tag2"))) > > int __tag1 * __tag1 __tag2 *g; > > the information will be encoded in dwarf. > > > > In BTF, the attribute is encoded as a new kind > > BTF_KIND_TYPE_TAG and latest bpf-next supports it. > > > > The patch added support in pahole, specifically > > converts llvm dwarf btf_type_tag attributes to > > BTF types. Please see individual patches for details. > > > > Changelog: > > v1 -> v2: > > - reorg an if condition to reduce nesting level. > > - add more comments to explain how to chain type tag types. > > > > Yonghong Song (4): > > libbpf: sync with latest libbpf repo > > dutil: move DW_TAG_LLVM_annotation definition to dutil.h > > dwarf_loader: support btf_type_tag attribute > > btf_encoder: support btf_type_tag attribute > > > > I thought that v1 was already applied, but either way LGTM. I'm not To the next branch, and the libbpf pahole CI is failing, since a few days, can you please take a look? > super familiar with the DWARF loader parts, so I mostly just read it > very superficially :) I replaced the patches that changed, re-added the S-o-B for Yonghong and tested it with llvm-project HEAD. > Acked-by: Andrii Nakryiko <andrii@kernel.org> Adding it to the csets. Thanks! - Arnaldo > > > btf_encoder.c | 7 +++ > > dutil.h | 4 ++ > > dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- > > dwarves.h | 38 +++++++++++++- > > lib/bpf | 2 +- > > pahole.c | 8 +++ > > 6 files changed, 190 insertions(+), 9 deletions(-) > > > > -- > > 2.30.2 > >
On 11/23/21 3:36 PM, Arnaldo Carvalho de Melo wrote: > Em Tue, Nov 23, 2021 at 10:32:18AM -0800, Andrii Nakryiko escreveu: >> On Mon, Nov 22, 2021 at 8:56 PM Yonghong Song <yhs@fb.com> wrote: >>> >>> btf_type_tag is a new llvm type attribute which is used similar >>> to kernel __user/__rcu attributes. The format of btf_type_tag looks like >>> __attribute__((btf_type_tag("tag1"))) >>> For the case where the attribute applied to a pointee like >>> #define __tag1 __attribute__((btf_type_tag("tag1"))) >>> #define __tag2 __attribute__((btf_type_tag("tag2"))) >>> int __tag1 * __tag1 __tag2 *g; >>> the information will be encoded in dwarf. >>> >>> In BTF, the attribute is encoded as a new kind >>> BTF_KIND_TYPE_TAG and latest bpf-next supports it. >>> >>> The patch added support in pahole, specifically >>> converts llvm dwarf btf_type_tag attributes to >>> BTF types. Please see individual patches for details. >>> >>> Changelog: >>> v1 -> v2: >>> - reorg an if condition to reduce nesting level. >>> - add more comments to explain how to chain type tag types. >>> >>> Yonghong Song (4): >>> libbpf: sync with latest libbpf repo >>> dutil: move DW_TAG_LLVM_annotation definition to dutil.h >>> dwarf_loader: support btf_type_tag attribute >>> btf_encoder: support btf_type_tag attribute >>> >> >> I thought that v1 was already applied, but either way LGTM. I'm not > > To the next branch, and the libbpf pahole CI is failing, since a few > days, can you please take a look? > >> super familiar with the DWARF loader parts, so I mostly just read it >> very superficially :) > > I replaced the patches that changed, re-added the S-o-B for Yonghong and > tested it with llvm-project HEAD. Thanks Arnaldo! > >> Acked-by: Andrii Nakryiko <andrii@kernel.org> > > Adding it to the csets. > > Thanks! > > - Arnaldo > >> >>> btf_encoder.c | 7 +++ >>> dutil.h | 4 ++ >>> dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- >>> dwarves.h | 38 +++++++++++++- >>> lib/bpf | 2 +- >>> pahole.c | 8 +++ >>> 6 files changed, 190 insertions(+), 9 deletions(-) >>> >>> -- >>> 2.30.2 >>> >
On Tue, Nov 23, 2021 at 3:36 PM Arnaldo Carvalho de Melo <acme@kernel.org> wrote: > > Em Tue, Nov 23, 2021 at 10:32:18AM -0800, Andrii Nakryiko escreveu: > > On Mon, Nov 22, 2021 at 8:56 PM Yonghong Song <yhs@fb.com> wrote: > > > > > > btf_type_tag is a new llvm type attribute which is used similar > > > to kernel __user/__rcu attributes. The format of btf_type_tag looks like > > > __attribute__((btf_type_tag("tag1"))) > > > For the case where the attribute applied to a pointee like > > > #define __tag1 __attribute__((btf_type_tag("tag1"))) > > > #define __tag2 __attribute__((btf_type_tag("tag2"))) > > > int __tag1 * __tag1 __tag2 *g; > > > the information will be encoded in dwarf. > > > > > > In BTF, the attribute is encoded as a new kind > > > BTF_KIND_TYPE_TAG and latest bpf-next supports it. > > > > > > The patch added support in pahole, specifically > > > converts llvm dwarf btf_type_tag attributes to > > > BTF types. Please see individual patches for details. > > > > > > Changelog: > > > v1 -> v2: > > > - reorg an if condition to reduce nesting level. > > > - add more comments to explain how to chain type tag types. > > > > > > Yonghong Song (4): > > > libbpf: sync with latest libbpf repo > > > dutil: move DW_TAG_LLVM_annotation definition to dutil.h > > > dwarf_loader: support btf_type_tag attribute > > > btf_encoder: support btf_type_tag attribute > > > > > > > I thought that v1 was already applied, but either way LGTM. I'm not > > To the next branch, and the libbpf pahole CI is failing, since a few > days, can you please take a look? We've had Clang regression which Yonghong fixed very quickly, but then we were blocked on Clang nightly builds being broken for days. Seems like we got a new Clang today, so hopefully libbpf CI will be back to green again. > > > super familiar with the DWARF loader parts, so I mostly just read it > > very superficially :) > > I replaced the patches that changed, re-added the S-o-B for Yonghong and > tested it with llvm-project HEAD. > > > Acked-by: Andrii Nakryiko <andrii@kernel.org> > > Adding it to the csets. > > Thanks! > > - Arnaldo > > > > > > btf_encoder.c | 7 +++ > > > dutil.h | 4 ++ > > > dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- > > > dwarves.h | 38 +++++++++++++- > > > lib/bpf | 2 +- > > > pahole.c | 8 +++ > > > 6 files changed, 190 insertions(+), 9 deletions(-) > > > > > > -- > > > 2.30.2 > > > > > -- > > - Arnaldo
Em Tue, Nov 23, 2021 at 08:49:17PM -0800, Andrii Nakryiko escreveu: > On Tue, Nov 23, 2021 at 3:36 PM Arnaldo Carvalho de Melo > <acme@kernel.org> wrote: > > > > Em Tue, Nov 23, 2021 at 10:32:18AM -0800, Andrii Nakryiko escreveu: > > > On Mon, Nov 22, 2021 at 8:56 PM Yonghong Song <yhs@fb.com> wrote: > > > > > > > > btf_type_tag is a new llvm type attribute which is used similar > > > > to kernel __user/__rcu attributes. The format of btf_type_tag looks like > > > > __attribute__((btf_type_tag("tag1"))) > > > > For the case where the attribute applied to a pointee like > > > > #define __tag1 __attribute__((btf_type_tag("tag1"))) > > > > #define __tag2 __attribute__((btf_type_tag("tag2"))) > > > > int __tag1 * __tag1 __tag2 *g; > > > > the information will be encoded in dwarf. > > > > > > > > In BTF, the attribute is encoded as a new kind > > > > BTF_KIND_TYPE_TAG and latest bpf-next supports it. > > > > > > > > The patch added support in pahole, specifically > > > > converts llvm dwarf btf_type_tag attributes to > > > > BTF types. Please see individual patches for details. > > > > > > > > Changelog: > > > > v1 -> v2: > > > > - reorg an if condition to reduce nesting level. > > > > - add more comments to explain how to chain type tag types. > > > > > > > > Yonghong Song (4): > > > > libbpf: sync with latest libbpf repo > > > > dutil: move DW_TAG_LLVM_annotation definition to dutil.h > > > > dwarf_loader: support btf_type_tag attribute > > > > btf_encoder: support btf_type_tag attribute > > > > > > > > > > I thought that v1 was already applied, but either way LGTM. I'm not > > > > To the next branch, and the libbpf pahole CI is failing, since a few > > days, can you please take a look? > > We've had Clang regression which Yonghong fixed very quickly, but then > we were blocked on Clang nightly builds being broken for days. Seems > like we got a new Clang today, so hopefully libbpf CI will be back to > green again. It is back to green, so I moved next to master, i.e. this series is now on master. - Arnaldo > > > > > super familiar with the DWARF loader parts, so I mostly just read it > > > very superficially :) > > > > I replaced the patches that changed, re-added the S-o-B for Yonghong and > > tested it with llvm-project HEAD. > > > > > Acked-by: Andrii Nakryiko <andrii@kernel.org> > > > > Adding it to the csets. > > > > Thanks! > > > > - Arnaldo > > > > > > > > > btf_encoder.c | 7 +++ > > > > dutil.h | 4 ++ > > > > dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- > > > > dwarves.h | 38 +++++++++++++- > > > > lib/bpf | 2 +- > > > > pahole.c | 8 +++ > > > > 6 files changed, 190 insertions(+), 9 deletions(-) > > > > > > > > -- > > > > 2.30.2 > > > > > > > > -- > > > > - Arnaldo
On 11/25/21 1:33 PM, Arnaldo Carvalho de Melo wrote: > Em Tue, Nov 23, 2021 at 08:49:17PM -0800, Andrii Nakryiko escreveu: >> On Tue, Nov 23, 2021 at 3:36 PM Arnaldo Carvalho de Melo >> <acme@kernel.org> wrote: >>> >>> Em Tue, Nov 23, 2021 at 10:32:18AM -0800, Andrii Nakryiko escreveu: >>>> On Mon, Nov 22, 2021 at 8:56 PM Yonghong Song <yhs@fb.com> wrote: >>>>> >>>>> btf_type_tag is a new llvm type attribute which is used similar >>>>> to kernel __user/__rcu attributes. The format of btf_type_tag looks like >>>>> __attribute__((btf_type_tag("tag1"))) >>>>> For the case where the attribute applied to a pointee like >>>>> #define __tag1 __attribute__((btf_type_tag("tag1"))) >>>>> #define __tag2 __attribute__((btf_type_tag("tag2"))) >>>>> int __tag1 * __tag1 __tag2 *g; >>>>> the information will be encoded in dwarf. >>>>> >>>>> In BTF, the attribute is encoded as a new kind >>>>> BTF_KIND_TYPE_TAG and latest bpf-next supports it. >>>>> >>>>> The patch added support in pahole, specifically >>>>> converts llvm dwarf btf_type_tag attributes to >>>>> BTF types. Please see individual patches for details. >>>>> >>>>> Changelog: >>>>> v1 -> v2: >>>>> - reorg an if condition to reduce nesting level. >>>>> - add more comments to explain how to chain type tag types. >>>>> >>>>> Yonghong Song (4): >>>>> libbpf: sync with latest libbpf repo >>>>> dutil: move DW_TAG_LLVM_annotation definition to dutil.h >>>>> dwarf_loader: support btf_type_tag attribute >>>>> btf_encoder: support btf_type_tag attribute >>>>> >>>> >>>> I thought that v1 was already applied, but either way LGTM. I'm not >>> >>> To the next branch, and the libbpf pahole CI is failing, since a few >>> days, can you please take a look? >> >> We've had Clang regression which Yonghong fixed very quickly, but then >> we were blocked on Clang nightly builds being broken for days. Seems >> like we got a new Clang today, so hopefully libbpf CI will be back to >> green again. > > It is back to green, so I moved next to master, i.e. this series is now > on master. Arnaldo, Is it possible that we could cut a pahole release in the near future? My kernel using btf_type_tag patch ([1]) needs a pahole version check. In old pahole versions, a warning about pointer type subtags not supported will be emitted and btf_type_tag attributes (as pointer type subtags) will be ignored. [1] https://lore.kernel.org/bpf/20211118184810.1846996-1-yhs@fb.com/ Thanks! > > - Arnaldo > >>> >>>> super familiar with the DWARF loader parts, so I mostly just read it >>>> very superficially :) >>> >>> I replaced the patches that changed, re-added the S-o-B for Yonghong and >>> tested it with llvm-project HEAD. >>> >>>> Acked-by: Andrii Nakryiko <andrii@kernel.org> >>> >>> Adding it to the csets. >>> >>> Thanks! >>> >>> - Arnaldo >>> >>>> >>>>> btf_encoder.c | 7 +++ >>>>> dutil.h | 4 ++ >>>>> dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- >>>>> dwarves.h | 38 +++++++++++++- >>>>> lib/bpf | 2 +- >>>>> pahole.c | 8 +++ >>>>> 6 files changed, 190 insertions(+), 9 deletions(-) >>>>> >>>>> -- >>>>> 2.30.2 >>>>> >>> >>> -- >>> >>> - Arnaldo >
btf_type_tag is a new llvm type attribute which is used similar to kernel __user/__rcu attributes. The format of btf_type_tag looks like __attribute__((btf_type_tag("tag1"))) For the case where the attribute applied to a pointee like #define __tag1 __attribute__((btf_type_tag("tag1"))) #define __tag2 __attribute__((btf_type_tag("tag2"))) int __tag1 * __tag1 __tag2 *g; the information will be encoded in dwarf. In BTF, the attribute is encoded as a new kind BTF_KIND_TYPE_TAG and latest bpf-next supports it. The patch added support in pahole, specifically converts llvm dwarf btf_type_tag attributes to BTF types. Please see individual patches for details. Changelog: v1 -> v2: - reorg an if condition to reduce nesting level. - add more comments to explain how to chain type tag types. Yonghong Song (4): libbpf: sync with latest libbpf repo dutil: move DW_TAG_LLVM_annotation definition to dutil.h dwarf_loader: support btf_type_tag attribute btf_encoder: support btf_type_tag attribute btf_encoder.c | 7 +++ dutil.h | 4 ++ dwarf_loader.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++--- dwarves.h | 38 +++++++++++++- lib/bpf | 2 +- pahole.c | 8 +++ 6 files changed, 190 insertions(+), 9 deletions(-)