Date: Fri, 19 Feb 2021 20:40:23 -0300 From: "Dr. Rolf Jansen" <freebsd-rj@obsigna.com> To: =?utf-8?B?TWljaGHFgiBHw7Nybnk=?= <mgorny@gentoo.org> Cc: freebsd-arm <freebsd-arm@freebsd.org>, Ed Maste <emaste@freebsd.org> Subject: Re: LLDB on FreeBSD/arm64 and arm Message-ID: <C8050FF4-8547-4DC0-BC2D-402ABB9E47A1@obsigna.com> In-Reply-To: <acafb4d2f5fe23cdf33d87d60e909847a034fbaf.camel@gentoo.org> References: <CAPyFy2A_E=fJwbRoL4uj4PvyeQ_Oz0v1xTOw3tkTQvJNfO3LbQ@mail.gmail.com> <E2CC3F9F-75DE-41F5-83BD-0179007583C2@obsigna.com> <fd58349e0b352636a8444418227b9ea5318360da.camel@gentoo.org> <9EDAF212-EA86-4AAC-97C6-BB801161DC4D@obsigna.com> <c6f9e733-627d-377c-84c4-22c7f12aec8f@gmail.com> <6FAC63F4-79D8-4D25-BC29-44371303A09B@obsigna.com> <acafb4d2f5fe23cdf33d87d60e909847a034fbaf.camel@gentoo.org>
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Am 17.02.2021 um 13:34 schrieb Micha=C5=82 G=C3=B3rny = <mgorny@gentoo.org>: > On Wed, 2021-02-17 at 12:21 -0300, Dr. Rolf Jansen wrote: >> Am 16.02.2021 um 11:01 schrieb Michal Meloun <meloun.michal@gmail.com = <mailto:meloun.michal@gmail.com>>: >>> On 16.02.2021 14:34, Dr. Rolf Jansen wrote: >>>> Am 05.02.2021 um 13:40 schrieb Micha=C5=82 G=C3=B3rny = <mgorny@gentoo.org>: >>>>> On Fri, 2021-02-05 at 12:30 -0300, Dr. Rolf Jansen wrote: >>>>>> Am 03.02.2021 um 14:53 schrieb Ed Maste <emaste@freebsd.org>: >>>>>>=20 >>>>>>> As you may know, the FreeBSD Foundation sponsored Moritz Systems = to >>>>>>> improve LLDB's support of non-x86 FreeBSD targets (and some = other >>>>>>> improvements applicable to all targets). This builds on their >>>>>>> earlier >>>>>>> work to update x86 support. >>>>>>>=20 >>>>>>> Initial changes for arm64 and arm support were recently = committed >>>>>>> upstream. Details are in these code reviews, if you're = interested: >>>>>>>=20 >>>>>>> https://reviews.llvm.org/D95297 (arm64) >>>>>>> https://reviews.llvm.org/D95696 (arm) >>>>>>>=20 >>>>>>> arm and arm64 users with an interest in LLDB are encouraged to = build >>>>>>> LLDB from the upstream git repository, try out the support, and >>>>>>> report >>>>>>> issues or positive results. >>>>>>>=20 >>>>>>> It should build using the regular build process as described at >>>>>>> https://lldb.llvm.org/resources/build.html >>>>>>>=20 >>>>>>> At present all four of 32- and 64-bit arm and x86 use LLDB's >>>>>>> non-legacy debug support by default. Legacy support will be = removed >>>>>>> from LLDB upon completion of Moritz' work (once all = architectures >>>>>>> are >>>>>>> patched) and there is no need to try out legacy support. >>>>>>=20 >>>>>> I am interested to build LLDB from the upstream repository. As a >>>>>> matter of fact a few years ago I did this already directly on a >>>>>> BeagleBone Black, however in the meantime the LLVM sources had = grown >>>>>> beyond the capacity a BBB could compile. Already at that time a = rather >>>>>> limited build took more than 48 hs. >>>>>>=20 >>>>>> I set up an ARMv7 cross building environment for kernel and world = on a >>>>>> reasonably equipped i7 machine. Can I somehow use this for = building >>>>>> LLDB as well? >>>>>=20 >>>>> Yes. See our summary for some tips: >>>>>=20 >>>>> = https://www.moritz.systems/blog/freebsd-remote-process-plugin-on-non-x86-a= rchitectures/ >>>>>=20 >>>>> Go for 'Cross-compiling LLVM'. On ARMv7, you'll have to change >>>>> the target and host triplets to = armv7-unknown-freebsd13.0-gnueabihf >>>>> and LLVM target to ARM. >>>>>=20 >>>>>> I provided ssh root access to one of my BBBs to Micha=C5=82 = G=C3=B3rny for >>>>>> testing his work, and he left a LLDB on the system, I don't know = at >>>>>> which stage, though. When debugging an advanced project of mine = with >>>>>> this one I see some show stoppers (as with the original LLDB). >>>>>> Perhaps, I could be of help to improve LLDB. >>>>>=20 >>>>> If it's about watchpoints, then we need to support them on kernel = level >>>>> first. For anything else, we need to figure out what's = wrong/missing. >>>> It took a while until I got it working - =E2=80=9Etoo many = variables, so few time=E2=80=9C >>>> In the toolchains file, I needed to add a definition for sysroot. = When passing it with the C_FLAGS and CXX_FLAGS, I got typical 32 vs. 64 = bit errors very early in the build process. Something like size_t is not = long. The working toolchain file for ARMv7 is the following =E2=80=94 = <SYSROOT> is the placeholder for the actual path, here it is = /root/install/BBB/sysroot: >>>> set(CMAKE_C_FLAGS "-target armv7-unknown-freebsd13.0-gnueabihf") >>>> set(CMAKE_CXX_FLAGS "-target = armv7-unknown-freebsd13.0-gnueabihf") >>>> set(CMAKE_SYSROOT <SYSROOT>) >>>> set(CMAKE_SYSTEM_NAME "FreeBSD") >>>> set(CMAKE_FIND_ROOT_PATH <SYSROOT>) >>>> set(CMAKE_FIND_ROOT_PATH_MODE_PROGRAM NEVER) >>>> set(CMAKE_FIND_ROOT_PATH_MODE_LIBRARY ONLY) >>>> set(CMAKE_FIND_ROOT_PATH_MODE_INCLUDE ONLY) >>>> Before, I found this out, I meandered between versions of LLVM (I = compiled 10.x, 11.x, 12.x and HEAD), and I switched to another build = machine, before it was FreeBSD 12.2-RELEASE on a real i7 and now I build = in a VM running FreeBSD 13.0-BETA2. However, without the definition of = CMAKE_SYSROOT all this did not work out. >>>> Now I deployed a lldb to my BeagleBone running 13-BETA2 as well: >>>> lldb version 13.0.0 (https://github.com/llvm/llvm-project.git = revision b40fde062c306584d88243de11175187e754ce3b) >>>> clang revision b40fde062c306584d88243de11175187e754ce3b >>>> llvm revision b40fde062c306584d88243de11175187e754ce3b >>>> I am able to debug simple programs, but the happiness ends already = when trying to enter a subroutine. At least this worked well with lldb = 11.0.1, which has been build by using in the course of world by = WORLD_FLAGS=3D"MK_LLDB=3Dyes=E2=80=9C. However both bail out, when I try = to debug a bigger project of mine. >>>> (lldb) target create "./CyDaemon" >>>> Current executable set to '/root/install/CyDaemon/CyDaemon' (arm). >>>> (lldb) settings set -- target.run-args "-f" "-l" "80" "-s" "443" >>>> (lldb) r >>>> Process 767 launched: '/root/install/CyDaemon/CyDaemon' (arm) >>>> Process 767 stopped >>>> * thread #1, name =3D 'CyDaemon', stop reason =3D signal SIGILL: = illegal instruction >>>> frame #0: 0x20290048 >>>> -> 0x20290048: vmull.p64 q0, d0, d0 >>>> 0x2029004c: bx lr >>>> 0x20290050: ldr r0, [pc, #0x68] >>>> 0x20290054: add r1, pc, #100 >>>> (lldb) >>>> The question now is, how to continue from here? Do we continue? If = yes, do we build on FreeBSD 13.0-RELEASE (BETAx for some more days) or = do we build on 14-CURRENT? Which version of lldb do we debug? A release = version or HEAD? >>>> The last lldb which worked absolutely well on the BBB was 3.9 or = was it 4.x. I know, that I never got 5.x to compile on the BBB. However = now, that my cross-building environment has been set up, I probably will = check that as well. >>>> Best regards >>>> Rolf >>>=20 >>> Hi Rolf, >>> This is quite normal behavior.. Your program uses crypt library ant = this library determines presence of crypto extension instructions = (Cortex A9 have not these). The library have SIGILL signal handler = installed and if vmull instruction is not supported it switches to pure = sw mode. In this case do nothing else press continue... >>=20 >> OK, this make sense. Actually, I need to continue 5 times. Now I pass = a startup script file on the lldb command line so it skips this = annoyance automatically: >>=20 >> -s lldbstartup >>=20 >> run >> process handle -n false -p true -s false SIGILL >> continue >>=20 >> I now compiled release/11.x and this works well, except the = longstanding issue, by which lldb in the GUI loses the focus when = stepping through a threaded program =E2=80=94 see = https://lists.llvm.org/pipermail/lldb-dev/2017-November/012954.html = <https://lists.llvm.org/pipermail/lldb-dev/2017-November/012954.html>; >>=20 >> Anyhow, this thread is about testing new features which made it into = LLDB for FreeBSD arm[64|], and my question remains, where did these = additions landed (main?, release/12.x?, release/11.x?) and what would I = test? >=20 > I'm sorry for not replying earlier. The newest LLDB work is only > available on main branch of llvm-project at the moment (12.0.0 RCs = were > already underway when we started). For most of the features any = recent > FreeBSD is fine (12-ish) but arm64 watchpoint support was just pushed = to > main. So, I am stuck with release/11.x, since compiling release/12.x errors = out and main does compile but with that I can only step into subroutines = in very simple code, however, when I use it with real world programs it = hangs when stepping in or over any subroutine call. For the time being, = I will stop these efforts. Best regards. Rolf=
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