From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 1879) id F03643856DC0; Fri, 21 Oct 2022 18:27:24 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org F03643856DC0 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1666376844; bh=TYy6dnlca0SQP8+oUrI7xpZ8BFWE8aDOSMM6yeUyZgs=; h=From:To:Subject:Date:From; b=Kl365aocWSzOuEZRPxnpt08OaKnRc985GifuB9WcjTLvZPgB/eCM7BMJ2s40MCQOZ Rdf1OF7F86tzN04dzrNFeI/g7aRuuZXgd885iGdmuyLtFty/FotV8A9LIA/WjN5NfQ k6eD3LFWadVSrUhMSBlbOwPg3ObdyygJSkZd4ddY= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable From: Simon Marchi To: gdb-cvs@sourceware.org Subject: [binutils-gdb] gdb: check for empty offsets vector in inherit_abstract_dies X-Act-Checkin: binutils-gdb X-Git-Author: Simon Marchi X-Git-Refname: refs/heads/master X-Git-Oldrev: 1f5a3546126b47fd3b7a5fbc4ec5fad1397b726b X-Git-Newrev: f2423983a8f4b5eba77b1d8510be022d600714b6 Message-Id: <20221021182724.F03643856DC0@sourceware.org> Date: Fri, 21 Oct 2022 18:27:24 +0000 (GMT) List-Id: https://sourceware.org/git/gitweb.cgi?p=3Dbinutils-gdb.git;h=3Df2423983a8f4= b5eba77b1d8510be022d600714b6 commit f2423983a8f4b5eba77b1d8510be022d600714b6 Author: Simon Marchi Date: Fri Oct 21 09:08:03 2022 -0400 gdb: check for empty offsets vector in inherit_abstract_dies =20 When building GDB with clang and --enable-ubsan, I get: =20 UNRESOLVED: gdb.dwarf2/frame-inlined-in-outer-frame.exp: starti prompt =20 The cause being: =20 $ ./gdb --data-directory=3Ddata-directory -nx -q -readnow testsuite= /outputs/gdb.dwarf2/frame-inlined-in-outer-frame/frame-inlined-in-outer-fra= me Reading symbols from testsuite/outputs/gdb.dwarf2/frame-inlined-in-= outer-frame/frame-inlined-in-outer-frame... Expanding full symbols from testsuite/outputs/gdb.dwarf2/frame-inli= ned-in-outer-frame/frame-inlined-in-outer-frame... /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:11954:47: runtime e= rror: applying non-zero offset 8 to null pointer =20 I found this to happen with ld-linux on at least Arch Linux and Ubuntu 22.04: =20 $ ./gdb --data-directory=3Ddata-directory -nx -q -readnow -iex "set= debuginfod enabled on" /lib64/ld-linux-x86-64.so.2 Reading symbols from /lib64/ld-linux-x86-64.so.2... Reading symbols from /home/simark/.cache/debuginfod_client/22bd7a2c= 03d8cfc05ef7092bfae5932223189bc1/debuginfo... Expanding full symbols from /home/simark/.cache/debuginfod_client/2= 2bd7a2c03d8cfc05ef7092bfae5932223189bc1/debuginfo... /home/simark/src/binutils-gdb/gdb/dwarf2/read.c:11954:47: runtime e= rror: applying non-zero offset 8 to null pointer =20 The problem happens when doing this: =20 sect_offset *offsetp =3D offsets.data () + 1 =20 When `offsets` is an empty vector, `offsets.data ()` returns nullptr. Fix it by wrapping that in a `!offsets.empty ()` check. =20 Change-Id: I6d29ba2fe80ba4308f68effd9c57d4ee8d67c29f Approved-By: Tom Tromey Diff: --- gdb/dwarf2/read.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/gdb/dwarf2/read.c b/gdb/dwarf2/read.c index cde7a5bd01f..077af064663 100644 --- a/gdb/dwarf2/read.c +++ b/gdb/dwarf2/read.c @@ -11949,17 +11949,22 @@ inherit_abstract_dies (struct die_info *die, stru= ct dwarf2_cu *cu) corresponding_abstract_child =3D corresponding_abstract_child->sibling; } =20 - std::sort (offsets.begin (), offsets.end ()); - sect_offset *offsets_end =3D offsets.data () + offsets.size (); - for (sect_offset *offsetp =3D offsets.data () + 1; - offsetp < offsets_end; - offsetp++) - if (offsetp[-1] =3D=3D *offsetp) - complaint (_("Multiple children of DIE %s refer " - "to DIE %s as their abstract origin"), - sect_offset_str (die->sect_off), sect_offset_str (*offsetp)); + if (!offsets.empty ()) + { + std::sort (offsets.begin (), offsets.end ()); + sect_offset *offsets_end =3D offsets.data () + offsets.size (); + for (sect_offset *offsetp =3D offsets.data () + 1; + offsetp < offsets_end; + offsetp++) + if (offsetp[-1] =3D=3D *offsetp) + complaint (_("Multiple children of DIE %s refer " + "to DIE %s as their abstract origin"), + sect_offset_str (die->sect_off), + sect_offset_str (*offsetp)); + } =20 sect_offset *offsetp =3D offsets.data (); + sect_offset *offsets_end =3D offsets.data () + offsets.size (); die_info *origin_child_die =3D origin_die->child; while (origin_child_die !=3D nullptr && origin_child_die->tag !=3D 0) {