On 06/09/2024 20:56, Eduard Zingerman wrote:
On Fri, 2024-09-06 at 14:24 +0100, Mykyta Yatsenko wrote:
From: Mykyta Yatsenko <yatsenko@xxxxxxxx>
Existing algorithm for BTF C dump sorting uses only types and names of
the structs and unions for ordering. As dump contains structs with the
same names but different contents, relative to each other ordering of
those structs will be accidental.
This patch addresses this problem by introducing a new sorting field
that contains hash of the struct/union field names and types to
disambiguate comparison of the non-unique named structs.
Signed-off-by: Mykyta Yatsenko <yatsenko@xxxxxxxx>
---
Note, this is still not fully stable, e.g.:
$ for i in $(seq 1 10); \
do touch ./kernel/bpf/verifier.c && \
ccache-kernel-make.sh -j23 && \
./tools/bpf/bpftool/bpftool btf dump file vmlinux format c > ~/work/tmp/vmlinux.h.$i; \
done
...
$ md5sum ~/work/tmp/vmlinux.h.* | sort -k1
76c9b22274c4aa6253ffaafa33ceffd3 /home/eddy/work/tmp/vmlinux.h.2
76c9b22274c4aa6253ffaafa33ceffd3 /home/eddy/work/tmp/vmlinux.h.4
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.1
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.10
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.3
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.5
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.6
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.7
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.8
a1c90a62e6cca59869a9cdffbaa3c4de /home/eddy/work/tmp/vmlinux.h.9
[...]
Interesting, thanks for showing this, I'll try to replicate this test.
