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Thu, 26 May 2022 02:02:13 -0700 (PDT) MIME-Version: 1.0 References: <00000000000038779505d5d8b372@google.com> <5e702296-9ce0-f1e6-dae8-cc719bc040b9@ghiti.fr> In-Reply-To: From: Atish Patra Date: Thu, 26 May 2022 02:02:02 -0700 Message-ID: Subject: Re: [syzbot] riscv/fixes boot error: can't ssh into the instance To: Alexandre Ghiti Cc: Dmitry Vyukov , Alexandre Ghiti , Aleksandr Nogikh , linux-riscv , kasan-dev , Palmer Dabbelt , syzbot , LKML , syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 26, 2022 at 1:11 AM Atish Patra wrote: > > On Mon, May 16, 2022 at 5:06 AM Alexandre Ghiti wrote: > > > > > > On 5/12/22 13:48, Dmitry Vyukov wrote: > > > On Fri, 18 Feb 2022 at 14:45, Alexandre Ghiti > > > wrote: > > >> Hi Aleksandr, > > >> > > >> On Thu, Feb 17, 2022 at 6:08 PM Aleksandr Nogikh wrote: > > >>> Hi Alex, > > >>> > > >>> On Thu, Feb 17, 2022 at 5:53 PM Alexandre Ghiti > > >>> wrote: > > >>>> Aleksandr, > > >>>> > > >>>> On Wed, Feb 16, 2022 at 5:58 PM Alexandre Ghiti > > >>>> wrote: > > >>>>> First, thank you for working on this. > > >>>>> > > >>>>> On Wed, Feb 16, 2022 at 5:17 PM Aleksandr Nogikh wrote: > > >>>>>> If I use just defconfig + DEBUG_VIRTUAL, without any KASAN, it begins > > >>>>>> to boot, but overwhelms me with tons of `virt_to_phys used for > > >>>>>> non-linear address:` errors. > > >>>>>> > > >>>>>> Like that > > >>>>>> > > >>>>>> [ 2.701271] virt_to_phys used for non-linear address: > > >>>>>> 00000000b59e31b6 (0xffffffff806c2000) > > >>>>>> [ 2.701727] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:16 > > >>>>>> __virt_to_phys+0x7e/0x86 > > >>>>>> [ 2.702207] Modules linked in: > > >>>>>> [ 2.702393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W > > >>>>>> 5.17.0-rc1 #1 > > >>>>>> [ 2.702806] Hardware name: riscv-virtio,qemu (DT) > > >>>>>> [ 2.703051] epc : __virt_to_phys+0x7e/0x86 > > >>>>>> [ 2.703298] ra : __virt_to_phys+0x7e/0x86 > > >>>>>> [ 2.703547] epc : ffffffff80008448 ra : ffffffff80008448 sp : > > >>>>>> ffff8f800021bde0 > > >>>>>> [ 2.703977] gp : ffffffff80ed9b30 tp : ffffaf8001230000 t0 : > > >>>>>> ffffffff80eea56f > > >>>>>> [ 2.704704] t1 : ffffffff80eea560 t2 : 0000000000000000 s0 : > > >>>>>> ffff8f800021be00 > > >>>>>> [ 2.705153] s1 : ffffffff806c2000 a0 : 000000000000004f a1 : > > >>>>>> ffffffff80e723d8 > > >>>>>> [ 2.705555] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : > > >>>>>> 0000000000000000 > > >>>>>> [ 2.706027] a5 : 0000000000000000 a6 : 0000000000000005 a7 : > > >>>>>> ffffffffffffffff > > >>>>>> [ 2.706474] s2 : ffffffff80b80b08 s3 : 00000000000000c2 s4 : > > >>>>>> ffffffff806c2000 > > >>>>>> [ 2.706891] s5 : ffffffff80edba10 s6 : ffffffff80edb960 s7 : > > >>>>>> 0000000000000001 > > >>>>>> [ 2.707290] s8 : 00000000000000ff s9 : ffffffff80b80b40 s10: > > >>>>>> 00000000000000cc > > >>>>>> [ 2.707689] s11: ffffaf807e1fcf00 t3 : 0000000000000076 t4 : > > >>>>>> ffffffffffffffff > > >>>>>> [ 2.708092] t5 : 00000000000001f2 t6 : ffff8f800021bb48 > > >>>>>> [ 2.708433] status: 0000000000000120 badaddr: 0000000000000000 > > >>>>>> cause: 0000000000000003 > > >>>>>> [ 2.708919] [] free_reserved_area+0x72/0x19a > > >>>>>> [ 2.709296] [] free_initmem+0x6c/0x7c > > >>>>>> [ 2.709648] [] kernel_init+0x3a/0x10a > > >>>>>> [ 2.709993] [] ret_from_exception+0x0/0xc > > >>>>>> [ 2.710310] ---[ end trace 0000000000000000 ]--- > > >>>>>> > > >>>>> I was able to reproduce this: the first one regarding init_zero_pfn is > > >>>>> legit but not wrong, I have to check when it was introduced and how to > > >>>>> fix this. > > >>>>> Regarding the huge batch that follows, at first sight, I would say > > >>>>> this is linked to my sv48 patchset but that does not seem important as > > >>>>> the address is a kernel mapping address so the use of virt_to_phys is > > >>>>> right. > > >>>>> > > >>>>>> On Wed, Feb 16, 2022 at 5:09 PM Aleksandr Nogikh wrote: > > >>>>>>> On Wed, Feb 16, 2022 at 12:56 PM Dmitry Vyukov wrote: > > >>>>>>>> On Wed, 16 Feb 2022 at 12:47, Aleksandr Nogikh wrote: > > >>>>>>>>> On Wed, Feb 16, 2022 at 11:37 AM Aleksandr Nogikh wrote: > > >>>>>>>>>> Hi Alex, > > >>>>>>>>>> > > >>>>>>>>>> On Wed, Feb 16, 2022 at 5:14 AM Alexandre Ghiti wrote: > > >>>>>>>>>>> Hi Dmitry, > > >>>>>>>>>>> > > >>>>>>>>>>> On 2/15/22 18:12, Dmitry Vyukov wrote: > > >>>>>>>>>>>> On Wed, 2 Feb 2022 at 14:18, Alexandre Ghiti > > >>>>>>>>>>>> wrote: > > >>>>>>>>>>>>> Hi Aleksandr, > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> On Wed, Feb 2, 2022 at 12:08 PM Aleksandr Nogikh wrote: > > >>>>>>>>>>>>>> Hello, > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> syzbot has already not been able to fuzz its RISC-V instance for 97 > > >>>>>>>>>>>>> That's a longtime, I'll take a look more regularly. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>>> days now because the compiled kernel cannot boot. I bisected the issue > > >>>>>>>>>>>>>> to the following commit: > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> commit 54c5639d8f507ebefa814f574cb6f763033a72a5 > > >>>>>>>>>>>>>> Author: Alexandre Ghiti > > >>>>>>>>>>>>>> Date: Fri Oct 29 06:59:27 2021 +0200 > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> riscv: Fix asan-stack clang build > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> Apparently, the problem appears on GCC-built RISC-V kernels with KASAN > > >>>>>>>>>>>>>> enabled. In the previous message syzbot mentions > > >>>>>>>>>>>>>> "riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU > > >>>>>>>>>>>>>> Binutils for Debian) 2.35.2", but the issue also reproduces finely on > > >>>>>>>>>>>>>> a newer GCC compiler: "riscv64-linux-gnu-gcc (Debian 11.2.0-10) > > >>>>>>>>>>>>>> 11.2.0, GNU ld (GNU Binutils for Debian) 2.37". > > >>>>>>>>>>>>>> For convenience, I also duplicate the .config file from the bot's > > >>>>>>>>>>>>>> message: https://syzkaller.appspot.com/x/.config?x=522544a2e0ef2a7d > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> Can someone with KASAN and RISC-V expertise please take a look? > > >>>>>>>>>>>>> I'll take a look at that today. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Thanks for reporting the issue, > > >>>>>>>>>>> I took a quick look, not enough to fix it but I know the issue comes > > >>>>>>>>>>> from the inline instrumentation, I have no problem with the outline > > >>>>>>>>>>> instrumentation. I need to find some cycles to work on this, my goal is > > >>>>>>>>>>> to fix this for 5.17. > > >>>>>>>>>> Thanks for the update! > > >>>>>>>>>> > > >>>>>>>>>> Can you please share the .config with which you tested the outline > > >>>>>>>>>> instrumentation? > > >>>>>>>>>> I updated the syzbot config to use KASAN_OUTLINE instead of KASAN_INLINE, > > >>>>>>>>>> but it still does not boot :( > > >>>>>>>>>> > > >>>>>>>>>> Here's what I used: > > >>>>>>>>>> https://gist.github.com/a-nogikh/279c85c2d24f47efcc3e865c08844138 > > >>>>>>>>> Update: it doesn't boot with that big config, but boots if I generate > > >>>>>>>>> a simple one with KASAN_OUTLINE: > > >>>>>>>>> > > >>>>>>>>> make defconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>>>> ./scripts/config -e KASAN -e KASAN_OUTLINE > > >>>>>>>>> make olddefconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>>>> > > >>>>>>>>> And it indeed doesn't work if I use KASAN_INLINE. > > >>>>>>>> It may be an issue with code size. Full syzbot config + KASAN + KCOV > > >>>>>>>> produce hugely massive .text. It may be hitting some limitation in the > > >>>>>>>> bootloader/kernel bootstrap code. > > >>>>> I took a quick glance and it traps on a KASAN address that is not > > >>>>> mapped, either because it is too soon or because the mapping failed > > >>>>> somehow. > > >>>>> > > >>>>> I'll definitely dive into that tomorrow, sorry for being slow here and > > >>>>> thanks again for all your work, that helps a lot. > > >>>>> > > >>>>> Thanks, > > >>>>> > > >>>>> Alex > > >>>>> > > >>>>>>> I bisected the difference between the config we use on syzbot and the > > >>>>>>> simple one that was generated like I described above. > > >>>>>>> Turns out that it's the DEBUG_VIRTUAL config that makes the difference. > > >>>>>>> > > >>>>>>> make defconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>> ./scripts/config -e KASAN -e KASAN_OUTLINE -e DEBUG_VIRTUAL > > >>>>>>> make olddefconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>> > > >>>>>>> And the resulting kernel does not boot. > > >>>>>>> My env: the `riscv/fixes` branch, commit > > >>>>>>> 6df2a016c0c8a3d0933ef33dd192ea6606b115e3, qemu 6.2.0. > > >>>> I fixed a few things today: KASAN + SPARSE_VMEMMAP, DEBUG_VIRTUAL and > > >>>> maybe KASAN + KCOV. > > >>>> > > >>>> With those small fixes, I was able to boot your large dotconfig with > > >>>> KASAN_OUTLINE, the inline version still fails, this is my next target > > >>>> :) > > >>>> I'll push that tomorrow! > > >>> Awesome, thank you very much! > > >>> Looking forward to finally seeing the instance run :) > > >> I sent a patchset which should fix your config with *outline* instrumentation. > > > Was this fix merged? The riscv instance still does not boot: > > > https://syzkaller.appspot.com/bug?id=5f2ff52ad42cba9f222202219baebd4e63e35127 > > > > > > Yes it has been in Linus tree since 5.18-rc1. I'll take a look at that > > this week. > > > > Are you seeing this error or a different one ? I used the > syzkaller_defconfig from the patch below on v5.18. > > https://lore.kernel.org/all/20220419174952.699-1-palmer@rivosinc.com/ > > [ 15.076116][ T1] Mandatory Access Control activated. > [ 15.158241][ T1] AppArmor: AppArmor Filesystem Enabled > [ 16.150870][ T1] NET: Registered PF_INET protocol family > [ 16.166167][ T1] IP idents hash table entries: 32768 (order: 6, > 262144 bytes, linear) > [ 16.188727][ T1] Unable to handle kernel paging request at > virtual address ffebfffeffff2000 > [ 16.192727][ T1] Oops [#1] > [ 16.193479][ T1] Modules linked in: > [ 16.194687][ T1] CPU: 3 PID: 1 Comm: swapper/0 Not tainted > 5.18.0-00001-g37ac279268bf-dirty #9 > [ 16.196486][ T1] Hardware name: riscv-virtio,qemu (DT) > [ 16.197836][ T1] epc : kasan_check_range+0x9e/0x14e > [ 16.199104][ T1] ra : memset+0x1e/0x4c > [ 16.200091][ T1] epc : ffffffff804787e0 ra : ffffffff80478f30 sp > : ff600000073ffb70 > [ 16.201420][ T1] gp : ffffffff85879e80 tp : ff600000073f0000 t0 > : 7300000000000000 > [ 16.202762][ T1] t1 : ffebfffeffff21ff t2 : 73746e6564692050 s0 > : ff600000073ffba0 > [ 16.204047][ T1] s1 : 0000000000001000 a0 : ffebfffeffff2200 a1 > : 0000000000001000 > [ 16.205312][ T1] a2 : 0000000000000001 a3 : ffffffff803a4f32 a4 > : ff5ffffffff90000 > [ 16.206592][ T1] a5 : ffebfffeffff2000 a6 : 0000004000000000 a7 > : ff5ffffffff90fff > [ 16.207865][ T1] s2 : ff5ffffffff90000 s3 : 0000000000000000 s4 > : ffffffff8467ea90 > [ 16.209134][ T1] s5 : 0000000000000000 s6 : ff5ffffffff90000 s7 > : 0000000000000000 > [ 16.210394][ T1] s8 : 0000000000001000 s9 : ffffffff8587ca40 > s10: 0000000000000004 > [ 16.211952][ T1] s11: ffffffff858a03a0 t3 : 0000000000000000 t4 > : 0000000000000040 > [ 16.213469][ T1] t5 : ffebfffeffff2200 t6 : ff600000073ff738 > [ 16.214853][ T1] status: 0000000200000120 badaddr: > ffebfffeffff2000 cause: 000000000000000d > [ 16.216910][ T1] Call Trace: > [ 16.217816][ T1] [] pcpu_alloc+0x844/0x1254 > [ 16.219110][ T1] [] __alloc_percpu+0x28/0x34 > [ 16.220244][ T1] [] ip_rt_init+0x17e/0x382 > [ 16.221606][ T1] [] ip_init+0x18/0x30 > [ 16.222719][ T1] [] inet_init+0x2a6/0x550 > [ 16.223863][ T1] [] do_one_initcall+0x130/0x7dc > [ 16.225002][ T1] [] kernel_init_freeable+0x510/0x5b4 > [ 16.226273][ T1] [] kernel_init+0x28/0x21c > [ 16.227337][ T1] [] ret_from_exception+0x0/0x10 > [ 16.229910][ T1] ---[ end trace 0000000000000000 ]--- > [ 16.231880][ T1] Kernel panic - not syncing: Fatal exception > > Enabling CONFIG_KASAN_VMALLOC=y solves the issue and I am able to boot to the userspace. I have tried enabling/disabling CONFIG_VMAP_STACK as well. Both works fine. Looking at the ARM64 Kconfig, KASAN_VMALLOC is enabled if KASAN is enabled. This diff seems to work for me. diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 00fd9c548f26..cbf0fe227c77 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -122,6 +122,7 @@ config RISCV select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU select ZONE_DMA32 if 64BIT + select KASAN_VMALLOC if KASAN I am not a kasan expert so I am not sure if this is the correct fix or just hides the real issue. pcpu_alloc seems to use vmalloc though. > > Thanks, > > > > Alex > > > > > > > > > >> However, as you'll see in the cover letter, I have an issue with > > >> another KASAN config and if you can take a look at the stacktrace and > > >> see if that rings a bell, that would be great. > > >> > > >> Don't hesitate next time to ping me when the riscv syzbot instance fails :) > > >> > > >> Alex > > >> > > >> > > >>> -- > > >>> Best Regards, > > >>> Aleksandr > > >>> > > >>>> Thanks again, > > >>>> > > >>>> Alex > > >> -- > > >> You received this message because you are subscribed to the Google Groups "kasan-dev" group. > > >> To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > > >> To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/CA%2BzEjCtB0rTuNAJkrM2q3JQL7D-9fAXBo0Ud0w__gy9CAfo_Ag%40mail.gmail.com. > > > > _______________________________________________ > > linux-riscv mailing list > > linux-riscv@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-riscv > > > > -- > Regards, > Atish -- Regards, Atish From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 926D7C433EF for ; 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b=Yd6tb7veqrrYDvhfhRZ6xMSwFqE1/QZYOovlC1FSFSCnPyb1BQD1ge6862cB00B+NI SYlK6BVUDe/s87snF+XvjQE5BKKUuGZMpwo7sJP0qLFEU3mA7hgSk6bI+RucjYNMWtj8 zvSuFrdJXL6rTSK0vel4tyLF5QMM4XCLhBhL4rxGVplL0/sWJF5YwwQCdzf3omEXHLFk YJUCKKeKcl5k03itujDmqyrw4lpwaZ2TRUuKSk069++WfRRaljsRuFjVZE6O7WZpMOJw Ket7BgjQ10v35/VnPezQsjv3AGqoMLu9bu9ID2XsG4+s+ZCiHd5X5kL+pOaC4HHc3rPv TIZw== X-Gm-Message-State: AOAM5323TlHN5IACydn5Qfbgpv3iUtmPz7StXEL7VPrR0TiQzYlU/nrG L1AIkIqKTvja+ypwE/KJkELjHzqu+31XfF1N2v2zGmndXhBY X-Google-Smtp-Source: ABdhPJwFMKsD6Mwni6LcKYjRCMR5eDEtJjD8W+JosiFs9Iig9A6+rQ4Qs4T55dUzAaYXIrI3whZ0dP4SljWelq3fdCQ= X-Received: by 2002:a81:238e:0:b0:300:642f:fdb2 with SMTP id j136-20020a81238e000000b00300642ffdb2mr5036721ywj.373.1653555733414; Thu, 26 May 2022 02:02:13 -0700 (PDT) MIME-Version: 1.0 References: <00000000000038779505d5d8b372@google.com> <5e702296-9ce0-f1e6-dae8-cc719bc040b9@ghiti.fr> In-Reply-To: From: Atish Patra Date: Thu, 26 May 2022 02:02:02 -0700 Message-ID: Subject: Re: [syzbot] riscv/fixes boot error: can't ssh into the instance To: Alexandre Ghiti Cc: Dmitry Vyukov , Alexandre Ghiti , Aleksandr Nogikh , linux-riscv , kasan-dev , Palmer Dabbelt , syzbot , LKML , syzkaller-bugs@googlegroups.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220526_020216_849693_512983E3 X-CRM114-Status: GOOD ( 49.19 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org On Thu, May 26, 2022 at 1:11 AM Atish Patra wrote: > > On Mon, May 16, 2022 at 5:06 AM Alexandre Ghiti wrote: > > > > > > On 5/12/22 13:48, Dmitry Vyukov wrote: > > > On Fri, 18 Feb 2022 at 14:45, Alexandre Ghiti > > > wrote: > > >> Hi Aleksandr, > > >> > > >> On Thu, Feb 17, 2022 at 6:08 PM Aleksandr Nogikh wrote: > > >>> Hi Alex, > > >>> > > >>> On Thu, Feb 17, 2022 at 5:53 PM Alexandre Ghiti > > >>> wrote: > > >>>> Aleksandr, > > >>>> > > >>>> On Wed, Feb 16, 2022 at 5:58 PM Alexandre Ghiti > > >>>> wrote: > > >>>>> First, thank you for working on this. > > >>>>> > > >>>>> On Wed, Feb 16, 2022 at 5:17 PM Aleksandr Nogikh wrote: > > >>>>>> If I use just defconfig + DEBUG_VIRTUAL, without any KASAN, it begins > > >>>>>> to boot, but overwhelms me with tons of `virt_to_phys used for > > >>>>>> non-linear address:` errors. > > >>>>>> > > >>>>>> Like that > > >>>>>> > > >>>>>> [ 2.701271] virt_to_phys used for non-linear address: > > >>>>>> 00000000b59e31b6 (0xffffffff806c2000) > > >>>>>> [ 2.701727] WARNING: CPU: 0 PID: 1 at arch/riscv/mm/physaddr.c:16 > > >>>>>> __virt_to_phys+0x7e/0x86 > > >>>>>> [ 2.702207] Modules linked in: > > >>>>>> [ 2.702393] CPU: 0 PID: 1 Comm: swapper/0 Tainted: G W > > >>>>>> 5.17.0-rc1 #1 > > >>>>>> [ 2.702806] Hardware name: riscv-virtio,qemu (DT) > > >>>>>> [ 2.703051] epc : __virt_to_phys+0x7e/0x86 > > >>>>>> [ 2.703298] ra : __virt_to_phys+0x7e/0x86 > > >>>>>> [ 2.703547] epc : ffffffff80008448 ra : ffffffff80008448 sp : > > >>>>>> ffff8f800021bde0 > > >>>>>> [ 2.703977] gp : ffffffff80ed9b30 tp : ffffaf8001230000 t0 : > > >>>>>> ffffffff80eea56f > > >>>>>> [ 2.704704] t1 : ffffffff80eea560 t2 : 0000000000000000 s0 : > > >>>>>> ffff8f800021be00 > > >>>>>> [ 2.705153] s1 : ffffffff806c2000 a0 : 000000000000004f a1 : > > >>>>>> ffffffff80e723d8 > > >>>>>> [ 2.705555] a2 : 0000000000000010 a3 : fffffffffffffffe a4 : > > >>>>>> 0000000000000000 > > >>>>>> [ 2.706027] a5 : 0000000000000000 a6 : 0000000000000005 a7 : > > >>>>>> ffffffffffffffff > > >>>>>> [ 2.706474] s2 : ffffffff80b80b08 s3 : 00000000000000c2 s4 : > > >>>>>> ffffffff806c2000 > > >>>>>> [ 2.706891] s5 : ffffffff80edba10 s6 : ffffffff80edb960 s7 : > > >>>>>> 0000000000000001 > > >>>>>> [ 2.707290] s8 : 00000000000000ff s9 : ffffffff80b80b40 s10: > > >>>>>> 00000000000000cc > > >>>>>> [ 2.707689] s11: ffffaf807e1fcf00 t3 : 0000000000000076 t4 : > > >>>>>> ffffffffffffffff > > >>>>>> [ 2.708092] t5 : 00000000000001f2 t6 : ffff8f800021bb48 > > >>>>>> [ 2.708433] status: 0000000000000120 badaddr: 0000000000000000 > > >>>>>> cause: 0000000000000003 > > >>>>>> [ 2.708919] [] free_reserved_area+0x72/0x19a > > >>>>>> [ 2.709296] [] free_initmem+0x6c/0x7c > > >>>>>> [ 2.709648] [] kernel_init+0x3a/0x10a > > >>>>>> [ 2.709993] [] ret_from_exception+0x0/0xc > > >>>>>> [ 2.710310] ---[ end trace 0000000000000000 ]--- > > >>>>>> > > >>>>> I was able to reproduce this: the first one regarding init_zero_pfn is > > >>>>> legit but not wrong, I have to check when it was introduced and how to > > >>>>> fix this. > > >>>>> Regarding the huge batch that follows, at first sight, I would say > > >>>>> this is linked to my sv48 patchset but that does not seem important as > > >>>>> the address is a kernel mapping address so the use of virt_to_phys is > > >>>>> right. > > >>>>> > > >>>>>> On Wed, Feb 16, 2022 at 5:09 PM Aleksandr Nogikh wrote: > > >>>>>>> On Wed, Feb 16, 2022 at 12:56 PM Dmitry Vyukov wrote: > > >>>>>>>> On Wed, 16 Feb 2022 at 12:47, Aleksandr Nogikh wrote: > > >>>>>>>>> On Wed, Feb 16, 2022 at 11:37 AM Aleksandr Nogikh wrote: > > >>>>>>>>>> Hi Alex, > > >>>>>>>>>> > > >>>>>>>>>> On Wed, Feb 16, 2022 at 5:14 AM Alexandre Ghiti wrote: > > >>>>>>>>>>> Hi Dmitry, > > >>>>>>>>>>> > > >>>>>>>>>>> On 2/15/22 18:12, Dmitry Vyukov wrote: > > >>>>>>>>>>>> On Wed, 2 Feb 2022 at 14:18, Alexandre Ghiti > > >>>>>>>>>>>> wrote: > > >>>>>>>>>>>>> Hi Aleksandr, > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> On Wed, Feb 2, 2022 at 12:08 PM Aleksandr Nogikh wrote: > > >>>>>>>>>>>>>> Hello, > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> syzbot has already not been able to fuzz its RISC-V instance for 97 > > >>>>>>>>>>>>> That's a longtime, I'll take a look more regularly. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>>> days now because the compiled kernel cannot boot. I bisected the issue > > >>>>>>>>>>>>>> to the following commit: > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> commit 54c5639d8f507ebefa814f574cb6f763033a72a5 > > >>>>>>>>>>>>>> Author: Alexandre Ghiti > > >>>>>>>>>>>>>> Date: Fri Oct 29 06:59:27 2021 +0200 > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> riscv: Fix asan-stack clang build > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> Apparently, the problem appears on GCC-built RISC-V kernels with KASAN > > >>>>>>>>>>>>>> enabled. In the previous message syzbot mentions > > >>>>>>>>>>>>>> "riscv64-linux-gnu-gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU > > >>>>>>>>>>>>>> Binutils for Debian) 2.35.2", but the issue also reproduces finely on > > >>>>>>>>>>>>>> a newer GCC compiler: "riscv64-linux-gnu-gcc (Debian 11.2.0-10) > > >>>>>>>>>>>>>> 11.2.0, GNU ld (GNU Binutils for Debian) 2.37". > > >>>>>>>>>>>>>> For convenience, I also duplicate the .config file from the bot's > > >>>>>>>>>>>>>> message: https://syzkaller.appspot.com/x/.config?x=522544a2e0ef2a7d > > >>>>>>>>>>>>>> > > >>>>>>>>>>>>>> Can someone with KASAN and RISC-V expertise please take a look? > > >>>>>>>>>>>>> I'll take a look at that today. > > >>>>>>>>>>>>> > > >>>>>>>>>>>>> Thanks for reporting the issue, > > >>>>>>>>>>> I took a quick look, not enough to fix it but I know the issue comes > > >>>>>>>>>>> from the inline instrumentation, I have no problem with the outline > > >>>>>>>>>>> instrumentation. I need to find some cycles to work on this, my goal is > > >>>>>>>>>>> to fix this for 5.17. > > >>>>>>>>>> Thanks for the update! > > >>>>>>>>>> > > >>>>>>>>>> Can you please share the .config with which you tested the outline > > >>>>>>>>>> instrumentation? > > >>>>>>>>>> I updated the syzbot config to use KASAN_OUTLINE instead of KASAN_INLINE, > > >>>>>>>>>> but it still does not boot :( > > >>>>>>>>>> > > >>>>>>>>>> Here's what I used: > > >>>>>>>>>> https://gist.github.com/a-nogikh/279c85c2d24f47efcc3e865c08844138 > > >>>>>>>>> Update: it doesn't boot with that big config, but boots if I generate > > >>>>>>>>> a simple one with KASAN_OUTLINE: > > >>>>>>>>> > > >>>>>>>>> make defconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>>>> ./scripts/config -e KASAN -e KASAN_OUTLINE > > >>>>>>>>> make olddefconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>>>> > > >>>>>>>>> And it indeed doesn't work if I use KASAN_INLINE. > > >>>>>>>> It may be an issue with code size. Full syzbot config + KASAN + KCOV > > >>>>>>>> produce hugely massive .text. It may be hitting some limitation in the > > >>>>>>>> bootloader/kernel bootstrap code. > > >>>>> I took a quick glance and it traps on a KASAN address that is not > > >>>>> mapped, either because it is too soon or because the mapping failed > > >>>>> somehow. > > >>>>> > > >>>>> I'll definitely dive into that tomorrow, sorry for being slow here and > > >>>>> thanks again for all your work, that helps a lot. > > >>>>> > > >>>>> Thanks, > > >>>>> > > >>>>> Alex > > >>>>> > > >>>>>>> I bisected the difference between the config we use on syzbot and the > > >>>>>>> simple one that was generated like I described above. > > >>>>>>> Turns out that it's the DEBUG_VIRTUAL config that makes the difference. > > >>>>>>> > > >>>>>>> make defconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>> ./scripts/config -e KASAN -e KASAN_OUTLINE -e DEBUG_VIRTUAL > > >>>>>>> make olddefconfig ARCH=riscv CROSS_COMPILE=riscv64-linux-gnu- > > >>>>>>> > > >>>>>>> And the resulting kernel does not boot. > > >>>>>>> My env: the `riscv/fixes` branch, commit > > >>>>>>> 6df2a016c0c8a3d0933ef33dd192ea6606b115e3, qemu 6.2.0. > > >>>> I fixed a few things today: KASAN + SPARSE_VMEMMAP, DEBUG_VIRTUAL and > > >>>> maybe KASAN + KCOV. > > >>>> > > >>>> With those small fixes, I was able to boot your large dotconfig with > > >>>> KASAN_OUTLINE, the inline version still fails, this is my next target > > >>>> :) > > >>>> I'll push that tomorrow! > > >>> Awesome, thank you very much! > > >>> Looking forward to finally seeing the instance run :) > > >> I sent a patchset which should fix your config with *outline* instrumentation. > > > Was this fix merged? The riscv instance still does not boot: > > > https://syzkaller.appspot.com/bug?id=5f2ff52ad42cba9f222202219baebd4e63e35127 > > > > > > Yes it has been in Linus tree since 5.18-rc1. I'll take a look at that > > this week. > > > > Are you seeing this error or a different one ? I used the > syzkaller_defconfig from the patch below on v5.18. > > https://lore.kernel.org/all/20220419174952.699-1-palmer@rivosinc.com/ > > [ 15.076116][ T1] Mandatory Access Control activated. > [ 15.158241][ T1] AppArmor: AppArmor Filesystem Enabled > [ 16.150870][ T1] NET: Registered PF_INET protocol family > [ 16.166167][ T1] IP idents hash table entries: 32768 (order: 6, > 262144 bytes, linear) > [ 16.188727][ T1] Unable to handle kernel paging request at > virtual address ffebfffeffff2000 > [ 16.192727][ T1] Oops [#1] > [ 16.193479][ T1] Modules linked in: > [ 16.194687][ T1] CPU: 3 PID: 1 Comm: swapper/0 Not tainted > 5.18.0-00001-g37ac279268bf-dirty #9 > [ 16.196486][ T1] Hardware name: riscv-virtio,qemu (DT) > [ 16.197836][ T1] epc : kasan_check_range+0x9e/0x14e > [ 16.199104][ T1] ra : memset+0x1e/0x4c > [ 16.200091][ T1] epc : ffffffff804787e0 ra : ffffffff80478f30 sp > : ff600000073ffb70 > [ 16.201420][ T1] gp : ffffffff85879e80 tp : ff600000073f0000 t0 > : 7300000000000000 > [ 16.202762][ T1] t1 : ffebfffeffff21ff t2 : 73746e6564692050 s0 > : ff600000073ffba0 > [ 16.204047][ T1] s1 : 0000000000001000 a0 : ffebfffeffff2200 a1 > : 0000000000001000 > [ 16.205312][ T1] a2 : 0000000000000001 a3 : ffffffff803a4f32 a4 > : ff5ffffffff90000 > [ 16.206592][ T1] a5 : ffebfffeffff2000 a6 : 0000004000000000 a7 > : ff5ffffffff90fff > [ 16.207865][ T1] s2 : ff5ffffffff90000 s3 : 0000000000000000 s4 > : ffffffff8467ea90 > [ 16.209134][ T1] s5 : 0000000000000000 s6 : ff5ffffffff90000 s7 > : 0000000000000000 > [ 16.210394][ T1] s8 : 0000000000001000 s9 : ffffffff8587ca40 > s10: 0000000000000004 > [ 16.211952][ T1] s11: ffffffff858a03a0 t3 : 0000000000000000 t4 > : 0000000000000040 > [ 16.213469][ T1] t5 : ffebfffeffff2200 t6 : ff600000073ff738 > [ 16.214853][ T1] status: 0000000200000120 badaddr: > ffebfffeffff2000 cause: 000000000000000d > [ 16.216910][ T1] Call Trace: > [ 16.217816][ T1] [] pcpu_alloc+0x844/0x1254 > [ 16.219110][ T1] [] __alloc_percpu+0x28/0x34 > [ 16.220244][ T1] [] ip_rt_init+0x17e/0x382 > [ 16.221606][ T1] [] ip_init+0x18/0x30 > [ 16.222719][ T1] [] inet_init+0x2a6/0x550 > [ 16.223863][ T1] [] do_one_initcall+0x130/0x7dc > [ 16.225002][ T1] [] kernel_init_freeable+0x510/0x5b4 > [ 16.226273][ T1] [] kernel_init+0x28/0x21c > [ 16.227337][ T1] [] ret_from_exception+0x0/0x10 > [ 16.229910][ T1] ---[ end trace 0000000000000000 ]--- > [ 16.231880][ T1] Kernel panic - not syncing: Fatal exception > > Enabling CONFIG_KASAN_VMALLOC=y solves the issue and I am able to boot to the userspace. I have tried enabling/disabling CONFIG_VMAP_STACK as well. Both works fine. Looking at the ARM64 Kconfig, KASAN_VMALLOC is enabled if KASAN is enabled. This diff seems to work for me. diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 00fd9c548f26..cbf0fe227c77 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -122,6 +122,7 @@ config RISCV select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU select ZONE_DMA32 if 64BIT + select KASAN_VMALLOC if KASAN I am not a kasan expert so I am not sure if this is the correct fix or just hides the real issue. pcpu_alloc seems to use vmalloc though. > > Thanks, > > > > Alex > > > > > > > > > >> However, as you'll see in the cover letter, I have an issue with > > >> another KASAN config and if you can take a look at the stacktrace and > > >> see if that rings a bell, that would be great. > > >> > > >> Don't hesitate next time to ping me when the riscv syzbot instance fails :) > > >> > > >> Alex > > >> > > >> > > >>> -- > > >>> Best Regards, > > >>> Aleksandr > > >>> > > >>>> Thanks again, > > >>>> > > >>>> Alex > > >> -- > > >> You received this message because you are subscribed to the Google Groups "kasan-dev" group. > > >> To unsubscribe from this group and stop receiving emails from it, send an email to kasan-dev+unsubscribe@googlegroups.com. > > >> To view this discussion on the web visit https://groups.google.com/d/msgid/kasan-dev/CA%2BzEjCtB0rTuNAJkrM2q3JQL7D-9fAXBo0Ud0w__gy9CAfo_Ag%40mail.gmail.com. > > > > _______________________________________________ > > linux-riscv mailing list > > linux-riscv@lists.infradead.org > > http://lists.infradead.org/mailman/listinfo/linux-riscv > > > > -- > Regards, > Atish -- Regards, Atish _______________________________________________ linux-riscv mailing list linux-riscv@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-riscv