From: Nick Alcock <nix@esperi.org.uk>
To: Kris Van Hees <kris.van.hees@oracle.com>
Cc: dtrace@lists.linux.dev, dtrace-devel@oss.oracle.com
Subject: Re: [PATCH 04/20] btf: deprecate dt_shared_btf and introduce btf->parent instead
Date: Fri, 06 Nov 2026 12:45:35 +0000 [thread overview]
Message-ID: <87zevmt9g0.fsf@esperi.org.uk> (raw)
In-Reply-To: <031b190cb7679c63673baf89f0389b9a@oracle.com>
On 30 Oct 2026, Kris Van Hees uttered the following:
> All module BTF (except vmlinux) share a common ancestor (the BTF data of
> the vmlinux module). Represent this with a btf->parent reference.
>
> For vmlinux, btf->parent will be NULL.
This seems like a good idea regardless.
> Signed-off-by: Kris Van Hees <kris.van.hees@oracle.com>
Reviewed-by: Nick Alcock <nix@esperi.org.uk>
> ---
> libdtrace/dt_btf.c | 517 +++++++++++++---------
> libdtrace/dt_btf.h | 19 +-
> libdtrace/dt_impl.h | 2 +-
> libdtrace/dt_module.c | 18 +-
> libdtrace/dt_open.c | 2 -
> libdtrace/dt_prov_fbt.c | 16 +-
> test/unittest/btf/test.x | 8 +
> test/unittest/btf/tst.elf-vmlinux.sh | 31 ++
> test/unittest/btf/tst.elf-vmlinux.x | 8 +
> test/unittest/btf/tst.invalid-fallback.sh | 31 ++
> test/unittest/btf/tst.invalid-fallback.x | 8 +
> test/unittest/btf/tst.module-btf.sh | 46 ++
> test/unittest/btf/tst.module-btf.x | 13 +
> test/unittest/btf/tst.module-local.sh | 63 +++
> test/unittest/btf/tst.module-local.x | 18 +
> test/unittest/btf/tst.module-parent.sh | 46 ++
> test/unittest/btf/tst.module-parent.x | 13 +
> test/unittest/btf/tst.raw-vmlinux.sh | 30 ++
> test/unittest/options/tst.ctf-only.sh | 27 ++
> test/unittest/options/tst.ctf-only.x | 8 +
> 20 files changed, 693 insertions(+), 231 deletions(-)
> create mode 100755 test/unittest/btf/test.x
> create mode 100755 test/unittest/btf/tst.elf-vmlinux.sh
> create mode 100755 test/unittest/btf/tst.elf-vmlinux.x
> create mode 100755 test/unittest/btf/tst.invalid-fallback.sh
> create mode 100755 test/unittest/btf/tst.invalid-fallback.x
> create mode 100755 test/unittest/btf/tst.module-btf.sh
> create mode 100755 test/unittest/btf/tst.module-btf.x
> create mode 100755 test/unittest/btf/tst.module-local.sh
> create mode 100755 test/unittest/btf/tst.module-local.x
> create mode 100755 test/unittest/btf/tst.module-parent.sh
> create mode 100755 test/unittest/btf/tst.module-parent.x
> create mode 100755 test/unittest/btf/tst.raw-vmlinux.sh
> create mode 100755 test/unittest/options/tst.ctf-only.sh
> create mode 100755 test/unittest/options/tst.ctf-only.x
>
> diff --git a/libdtrace/dt_btf.c b/libdtrace/dt_btf.c
> index dce44987..194a251c 100644
> --- a/libdtrace/dt_btf.c
> +++ b/libdtrace/dt_btf.c
> @@ -32,8 +32,8 @@ struct dt_btf {
> size_t size; /* raw BTF data size */
> btf_header_t *hdr; /* BTF header */
> char *sdata; /* string data */
> - uint32_t ssize; /* string data size */
(this seems to be unused, so dropping it is ok.)
> + /*
> + * If we were not able to read the BTF data, and we are constructing
> + * 'shared_ctf', we need space for the default 'void' type.
> + */
Isn't shared_ctf already gone by this point?
--
NULL && (void)
next prev parent reply other threads:[~2026-11-06 12:45 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-30 19:36 [PATCH 04/20] btf: deprecate dt_shared_btf and introduce btf->parent instead Kris Van Hees
2026-11-06 12:45 ` Nick Alcock [this message]
2026-11-07 15:39 ` Kris Van Hees
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