[PATCH dwarves 0/2] dwarf_loader: improve cus__merging_cu()

From: Yonghong Song <yhs@fb.com>
To: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>,
	<dwarves@vger.kernel.org>
Cc: "Alexei Starovoitov" <ast@kernel.org>,
	"Andrii Nakryiko" <andrii@kernel.org>,
	"Bill Wendling" <morbo@google.com>,
	bpf@vger.kernel.org, "David Blaikie" <dblaikie@gmail.com>,
	"Fāng-ruì Sòng" <maskray@google.com>,
	kernel-team@fb.com, "Nick Desaulniers" <ndesaulniers@google.com>
Subject: [PATCH dwarves 0/2] dwarf_loader: improve cus__merging_cu()
Date: Wed, 31 Mar 2021 19:58:15 -0700	[thread overview]
Message-ID: <20210401025815.2254256-1-yhs@fb.com> (raw)

Function cus__merging_cu() is introduced in Commit 39227909db3c
("dwarf_loader: Permit merging all DWARF CU's for clang LTO built
binary") to test whether cross-cu references may happen.
The original implementation anticipates compilation flags
in dwarf, but later some concerns about binary size surfaced
and the decision is to scan .debug_abbrev as a faster way
to check cross-cu references. Also putting a note in vmlinux
to indicate whether lto is enabled for built or not can
provide a much faster way.

This patch set implemented this two approaches, first
checking the note (in Patch #2), if not found, then
check .debug_abbrev (in Patch #1).

Yonghong Song (2):
  dwarf_loader: check .debug_abbrev for cross-cu references
  dwarf_loader: check .notes section for lto build info

 dwarf_loader.c | 76 ++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 55 insertions(+), 21 deletions(-)

-- 
2.30.2