From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A1B5E3858D38; Mon, 22 Apr 2024 12:31:08 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A1B5E3858D38 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1713789068; bh=HsLypNUeAjflBwKitFE5gjBsRMBi66xdCTh6cCXW2Rs=; h=From:To:Subject:Date:From; b=NvsEt8hEIxFZXvk+4/7ISJH9UI6CRqa0k0eHG6XEYiw3XbBATfmR30Ll0F9nzPsVt GJzS2yIv1sYerQc84qIuCVSNZfOrFAVNyBNWmLK0IeJjhwmmP6l8egwd0uJ+g9U+QB XStWF3EUGzhjsG2CWYL1XvgjvvBv1f19xntvLGy0= From: "k4lizen at proton dot me" To: gdb-prs@sourceware.org Subject: [Bug gdb/31669] New: wrong "info symbol" output, symbol shadowing, __dso_handle Date: Mon, 22 Apr 2024 12:31:07 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gdb X-Bugzilla-Component: gdb X-Bugzilla-Version: 13.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: k4lizen at proton dot me X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: unassigned at sourceware dot org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone attachments.created Message-ID: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable X-Bugzilla-URL: http://sourceware.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 List-Id: https://sourceware.org/bugzilla/show_bug.cgi?id=3D31669 Bug ID: 31669 Summary: wrong "info symbol" output, symbol shadowing, __dso_handle Product: gdb Version: 13.1 Status: UNCONFIRMED Severity: normal Priority: P2 Component: gdb Assignee: unassigned at sourceware dot org Reporter: k4lizen at proton dot me Target Milestone: --- Created attachment 15478 --> https://sourceware.org/bugzilla/attachment.cgi?id=3D15478&action=3Ded= it The file I encountered this issue with gdb version: GNU gdb (Debian 13.2-1) 13.2 OS: Linux kali 6.6.9-amd64 In the attachment is the ELF I encountered the issue with. I initially submitted an issue downstream: https://github.com/pwndbg/pwndbg/issues/2116. Due to the way "info symbol" is used in pwndbg, it would be nice if this bug was patched. The issue: Doing `info symbol 0x402367` gives `__dso_handle + 863 [...]` although the value stored at 0x402367 has nothing to do with __dso_handle. The values at 0x402367 and 0x402a27 are the strings "r" and "./flag.txt" which are passed= to fopen near the start of the main function. Notable: + The __dso_handle symbol seems to be registered even before libc is loaded, but after libc is loaded doing "p __dso_handle" prints the symbol in libc. = Is the symbol supposed to be there before libc is loaded? It exists before lib= c in multiple elfs I tried. + Is there a way to make "print" print the value of __dso_handle in terminal.bin after libc is loaded? + I'm not sure if the bug is in "info symbol" and how it checks when a symb= ol "ends" or with the handling of __dso_handle in particular. =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D hacker@kali ~/m/gdbbugsymbols> gdb terminal.bin GNU gdb (Debian 13.2-1) 13.2 [..copyright snip..] Reading symbols from terminal.bin... (No debugging symbols found in terminal.bin) (gdb) x &__dso_handle 0x402008: 0x00000000 (gdb) break main Breakpoint 1 at 0x401d9e (gdb) run Starting program: /home/hacker/mine/gdbbugsymbols/terminal.bin [Thread debugging using libthread_db enabled] Using host libthread_db library "/lib/x86_64-linux-gnu/libthread_db.so.1". Breakpoint 1, 0x0000000000401d9e in main () (gdb) x &__dso_handle 0x7ffff7f9a780 <__dso_handle>: 0xf7f9a780 (gdb) info symbol 0x402367 __dso_handle + 863 in section .rodata of /home/hacker/mine/gdbbugsymbols/terminal.bin (gdb) info symbol 0x402008 __dso_handle in section .rodata of /home/hacker/mine/gdbbugsymbols/terminal= .bin (gdb) info symbol 0x7ffff7f9a780 __dso_handle in section .data.rel.ro of /lib/x86_64-linux-gnu/libc.so.6 (gdb) =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --=20 You are receiving this mail because: You are on the CC list for the bug.=