From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16056 invoked by alias); 11 Dec 2015 13:04:55 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 16042 invoked by uid 89); 11 Dec 2015 13:04:55 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.6 required=5.0 tests=AWL,BAYES_00,SPF_PASS autolearn=ham version=3.3.2 X-HELO: usplmg20.ericsson.net Received: from usplmg20.ericsson.net (HELO usplmg20.ericsson.net) (198.24.6.45) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-SHA encrypted) ESMTPS; Fri, 11 Dec 2015 13:04:54 +0000 Received: from EUSAAHC005.ericsson.se (Unknown_Domain [147.117.188.87]) by usplmg20.ericsson.net (Symantec Mail Security) with SMTP id 96.E2.06940.969CA665; Fri, 11 Dec 2015 14:02:34 +0100 (CET) Received: from [142.133.110.95] (147.117.188.8) by smtp-am.internal.ericsson.com (147.117.188.89) with Microsoft SMTP Server id 14.3.248.2; Fri, 11 Dec 2015 08:04:51 -0500 Subject: Re: [PATCH v7 3/8] Use xml-syscall to compare syscall numbers in arm_linux_sigreturn_return-addr. To: Pedro Alves , Yao Qi References: <1449583641-18156-1-git-send-email-antoine.tremblay@ericsson.com> <1449583641-18156-4-git-send-email-antoine.tremblay@ericsson.com> <86io45ql3x.fsf@gmail.com> <566ABA91.5000508@redhat.com> <566ABB44.3080004@gmail.com> <566ABC0C.10101@redhat.com> <566AC23B.6060800@ericsson.com> <566AC5EA.4090204@redhat.com> CC: From: Antoine Tremblay Message-ID: <566AC9F2.8090906@ericsson.com> Date: Fri, 11 Dec 2015 13:04:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:38.0) Gecko/20100101 Thunderbird/38.4.0 MIME-Version: 1.0 In-Reply-To: <566AC5EA.4090204@redhat.com> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit X-IsSubscribed: yes X-SW-Source: 2015-12/txt/msg00227.txt.bz2 On 12/11/2015 07:47 AM, Pedro Alves wrote: > On 12/11/2015 12:31 PM, Antoine Tremblay wrote: >> >> >> On 12/11/2015 07:05 AM, Pedro Alves wrote: >>> On 12/11/2015 12:02 PM, Yao Qi wrote: >>>> On 11/12/15 11:59, Pedro Alves wrote: >>>>> but then you might as well just do: >>>>> >>>>> #define ARM_SIGRETURN 119 >>>> >>>> How about using __NR_sigreturn and __NR_rt_sigreturn directly? like >>>> what patch #6 does. >>> >>> Those are host/native macros. Only make sense for the running host. >>> Can't use that in a tdep file, like arm-linux-tdep.c. Otherwise, e.g., >>> a x86-hosted cross debugger would be using the x86 __NR_sigreturn, etc. >>> >> >> Exactly that's why I use those only in GDBServer. > > Hmm, actually, that sounds wrong. > > What about Aarch64 gdbserver debugging Aarch32? > > I see that the new code in question in patch #6 is in gdbserver/linux-arm-low.c, > which is not built on Aarch64, but, shouldn't that new arm_sigreturn_next_pc > code be used in the biarch scenario as well? > This is only used if we need software single stepping, I think in that case hardware single stepping will be used on aarch64 even if stepping over an arm32 program, Yao can confirm ? > If you just made that 32-bit-specific code compile on Aarch64 it would > be compiling against Aarch64's __NR_sigreturn, which I'd assume is wrong for Aarch32. > >> Looking at the kernel code in linux/arch/arm64 I see : include/asm/unistd.h:#define __NR_compat_sigreturn 119 include/asm/unistd.h:#define __NR_compat_rt_sigreturn 173 include/asm/unistd32.h:#define __NR_sigreturn 119 include/asm/unistd32.h:__SYSCALL(__NR_sigreturn, compat_sys_sigreturn_wrapper) include/asm/unistd32.h:#define __NR_rt_sigreturn 173 include/asm/unistd32.h:__SYSCALL(__NR_rt_sigreturn, compat_sys_rt_sigreturn_wrapper) So I think it's ok... but I can't compile on aarch64 at the moment. >> Personally while I like the #define ARM_SIGRETURN 119 better, I think >> the xml function is fine. >> > > If you added > > #define ARM_LINUX_SIGRETURN 119 > > to arch/arm-linux.h > > you could use it in both places. That was my first thought, I would be OK with that if Yao is too, however I think both methods work.