From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from simark.ca (simark.ca [158.69.221.121]) by sourceware.org (Postfix) with ESMTPS id 27A08385F020 for ; Thu, 19 Mar 2020 15:30:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 27A08385F020 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=simark.ca Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=simark@simark.ca Received: from [172.16.0.95] (192-222-181-218.qc.cable.ebox.net [192.222.181.218]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by simark.ca (Postfix) with ESMTPSA id 84A801E5F9; Thu, 19 Mar 2020 11:30:25 -0400 (EDT) Subject: Re: [PATCH v4] Disable get_ptrace_pid for NetBSD From: Simon Marchi To: Kamil Rytarowski , gdb-patches@sourceware.org Cc: tom@tromey.com References: <20200318231651.18045-1-n54@gmx.com> <20200319122844.24558-1-n54@gmx.com> <3bbb5348-a6bb-fac2-3ca1-2a3e8a1eb11e@simark.ca> Message-ID: <6e74c142-d3e7-6fd8-b765-594931be898b@simark.ca> Date: Thu, 19 Mar 2020 11:30:24 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <3bbb5348-a6bb-fac2-3ca1-2a3e8a1eb11e@simark.ca> Content-Type: text/plain; charset=utf-8 Content-Language: tl Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=0.0 required=5.0 tests=KAM_DMARC_STATUS, SPF_HELO_PASS, SPF_PASS autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 19 Mar 2020 15:30:27 -0000 On 2020-03-19 8:55 a.m., Simon Marchi wrote: > On 2020-03-19 8:28 a.m., Kamil Rytarowski wrote: >> Unlike most other Operating Systems, NetBSD tracks both pid and lwp. >> The process id on NetBSD is stored always in the pid field of ptid. >> >> gdb/ChangeLog: >> >> * inf-ptrace.h: Disable get_ptrace_pid on NetBSD. >> * inf-ptrace.c: Likewise. >> * (gdb_ptrace): Add. >> * (inf_ptrace_target::resume): Update. >> * (inf_ptrace_target::xfer_partial): Likewise. >> * (inf_ptrace_peek_poke): Change argument `pid' to `ptid'. >> * (inf_ptrace_peek_poke): Update. > > Hmm, this breaks simple debugging on Linux: > > $ ./gdb --data-directory=data-directory a.out -ex start > Reading symbols from a.out... > Temporary breakpoint 1 at 0x4004da: file test.c, line 2. > Starting program: /home/smarchi/build/binutils-gdb/gdb/a.out > > Program received signal SIGILL, Illegal instruction. > 0x00007ffff7dda96d in dl_main (phdr=, phnum=, user_entry=, auxv=) at rtld.c:1517 > 1517 rtld.c: No such file or directory. > > > I haven't figured out why by inspecting the code yet, I'll try to debug it later today. > > Simon > Ah, it's because ptrace returns long and not int on GNU/Linux. So when we want to read a 64-bits word from memory, it gets truncated. gdb_ptrace should return PTRACE_TYPE_RET. In fact, to be consistent, all these gdb_ptrace functions should be changed to return PTRACE_TYPE_RET (as a separate patch). Simon