From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: ARC-Seal: i=1; a=rsa-sha256; t=1523269510; cv=none; d=google.com; s=arc-20160816; b=iS2AOj8FtroNIOLjAa5sSpRRVyw67oKh8rJPd0yUoYIxVYj9xD5pWgD1kzx1vJafoE OCR62hTS7lbqHMdAmLFd+fdxu4oEmVkwTVb9A5p2S/X9SnuO+6GSy/TKiM3oaaSE4K3C p7j62+QwdO6pyw9x2R/aEvAHti+Fw3gKq0mdlVYenrB65SPUn+RuxoG0VAKvsPPB4p16 I4pBXsMHCZJOyss8G3Ypf7Vaaz2RVsvW/xBiFVGd3zyW2cYxCc3coi/xM4UoRwTficS3 Iwc2hBL6w2PGaApH6n6G8h4bSdmwuXUuC3i6CO1TKmotJisOWQpSkA5CAsNTjyh/Cmqu KULQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=to:references:message-id:content-transfer-encoding:cc:date :in-reply-to:from:subject:mime-version:dkim-signature :arc-authentication-results; bh=U6nIJzauH9yLUJyBjteaUlo/bE9Gp0fsJPPXmKqCwHk=; b=W9iRnrDQl8/zmUnD+daOgZ7KWcO7wZT0fCRHjdBEuk27uYrFNXtV63ZtYjkNnU9jRP 1VH+W1vN+BewJ/G4QHdsxflDkLd9+DBxyIMIy7p8CuluYTjBbyggVysmy2QljrauIlbw cD5aGuvDySNM73yIQLHCTb5IP1fgiCL5WIxGu+J6oBXCCkHMirt2HfGhPweH6siIS/Eb exr9km4GBUWRIqk37YV41eDiekfBMHKVk+Gd3WWRalapRCKxMRAAQzT237Btl0vL2irZ E+jPtNHcCHLs0zfrtyR99f+5hKwdcLaLBVXQPVrogleZ2LK11on8Sr/TB1YJ/uRsvNH4 6WGg== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=R1+lnEUC; spf=pass (google.com: domain of ard.biesheuvel@linaro.org designates 209.85.220.41 as permitted sender) smtp.mailfrom=ard.biesheuvel@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org Authentication-Results: mx.google.com; dkim=pass header.i=@linaro.org header.s=google header.b=R1+lnEUC; spf=pass (google.com: domain of ard.biesheuvel@linaro.org designates 209.85.220.41 as permitted sender) smtp.mailfrom=ard.biesheuvel@linaro.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=linaro.org X-Google-Smtp-Source: AIpwx4/hFt/Ki8VXK0VWDZJ9YnRSYHaHVOj9vwCMw37LEKPymQEz9a2T2TTVyczphxOKo/FoK9s0bQ== Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (1.0) Subject: Re: Linux 4.9.93 From: Ard Biesheuvel X-Mailer: iPhone Mail (15C202) In-Reply-To: <20180409185751.247a0ac7@jbtheou> Date: Mon, 9 Apr 2018 12:25:07 +0200 Cc: Greg KH , Mark Rutland , Linux Kernel Mailing List , Will Deacon , Dan Rue , Mark Brown , Marc Zyngier , Greg Hackmann Content-Transfer-Encoding: quoted-printable Message-Id: <40BB2246-DD5D-4956-ADFA-6143FCC98D1B@linaro.org> References: <20180409180534.1768583293d0abe207168c5a@essential.com> <20180409093028.GA3398@kroah.com> <20180409185751.247a0ac7@jbtheou> To: Jean-Baptiste Theou X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1597258846269332204?= X-GMAIL-MSGID: =?utf-8?q?1597263850484712420?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: > On 9 Apr 2018, at 11:57, Jean-Baptiste Theou wrote: >=20 > On Mon, 9 Apr 2018 11:49:37 +0200 > Ard Biesheuvel wrote: >=20 >>> On 9 April 2018 at 11:30, Greg KH wrote: >>>> On Mon, Apr 09, 2018 at 06:05:34PM +0900, Jean-Baptiste Theou wrote: =20= >>>> Hi, >>>>=20 >>>> After this patchset, a kernel built with CFI fails. Disabling >>>> UNMAP_KERNEL_AT_EL0 fix the issue obviously. =20 >>=20 >> How does one 'build a kernel with CFI' for arm64? >=20 > =46rom Google work on Android-4.9 >=20 > https://android.googlesource.com/kernel/common/+/00a195e7c0752ff5d65c9caad= fbcc226270ca232 >=20 > I am not sure what is the plan on their side to upstream (Greg?), but defi= nitely > useful to isolate actual issues. >=20 >>=20 >>>=20 >>> Is this a "clean" 4.9.93 tree or a "4.9.93 merged into >>> android-common-4.9? >=20 > It's a "clean 4.9.93" + whatever is needed for Clang/CFI support >=20 > My take is that CFI doesn't like=20 >=20 > * void __kpti_install_ng_mappings(int cpu, int num_cpus, phys_addr_t swapp= er) >=20 > and=20 >=20 > remap_fn =3D (void *)__pa_symbol(idmap_kpti_install_ng_mappings); >=20 > Maybe just flag this function to not use CFI? I remember that Sami Tolvane= n did > similar changes. >=20 > I know it's a bit out of context since CFI support for ARM64 is not upstre= am yet, > but unfortunate that an stable patchset trigger such failures. >=20 I am sorry but if you are implying that we should have tested these patches a= gainst the out of tree CFI code, I have to disappoint you: that is simply no= t upstream=E2=80=99s job, and if the Google engineers merged this into their= v4.9 tree without proper testing, may I suggest that you report it to them i= nstead? OTOH, if that is not what you are implying, please ignore the rant :-) > Thanks a lot >=20 > Best regards >=20 >>>=20 >>>> Wondering if there is one of the test suite used on the review patchset= that covers the CFI usecase. >>>>=20 >>>> Best regards, >>>>=20 >>>> [ 0.249191] CPU features: detected feature: GIC system register CPU i= nterface >>>> [ 0.256391] CPU features: detected feature: Privileged Access Never >>>> [ 0.262719] CPU features: detected feature: User Access Override >>>> [ 0.268791] CPU features: detected feature: 32-bit EL0 Support >>>> [ 0.274683] CPU features: detected feature: Kernel page table isolat= ion (KPTI) >>>> [ 0.282166] CFI failure: >>>> [ 0.282169] CFI failure: >>>> [ 0.282172] CFI failure: >>>> [ 0.282173] CFI failure: >>>> [ 0.282175] CFI failure: >>>> [ 0.282176] CFI failure: >>>> [ 0.282177] CFI failure: >>>> [ 0.282178] CFI failure: >>>> [ 0.282188] ------------[ cut here ]------------ >>>> [ 0.282189] ------------[ cut here ]------------ >>>> [ 0.282190] ------------[ cut here ]------------ >>>> [ 0.282191] ------------[ cut here ]------------ >>>> [ 0.282193] ------------[ cut here ]------------ >>>> [ 0.282196] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282198] ------------[ cut here ]------------ >>>> [ 0.282201] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282202] ------------[ cut here ]------------ >>>> [ 0.282204] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282207] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282209] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282211] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282214] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282215] ------------[ cut here ]------------ >>>> [ 0.282216] kernel BUG at kernel/cfi.c:32! >>>> [ 0.282218] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP >>>> [ 0.282224] Modules linked in: >>>> [ 0.282230] CPU: 2 PID: 25 Comm: migration/2 Not tainted 4.9.93-perf= + #39 >>>> [ 0.282232] Hardware name: >>>> [ 0.282235] task: fffffffbb3b36580 task.stack: fffffffbb30cc000 >>>> [ 0.282250] PC is at __cfi_check_fail+0x14/0x1c >>>> [ 0.282253] LR is at __cfi_check_fail+0x14/0x1c >>>> [ 0.282255] pc : [] lr : [] psta= te: 60c00085 >>>> [ 0.282256] sp : fffffffbb30cfc30 >>>> [ 0.282259] x29: fffffffbb30cfc30 x28: ffffff93b6415000 >>>> [ 0.282261] x27: 00000013b65c1000 x26: ffffff93b5ce6000 >>>> [ 0.282264] x25: ffffff93b5ce6000 x24: ffffff93b6419000 >>>> [ 0.282266] x23: ffffff93b65c1000 x22: ffffff93b65c4000 >>>> [ 0.282268] x21: 9d12f8172cb2f296 x20: 000000008180e3e0 >>>> [ 0.282271] x19: 0000000000000000 x18: 000000000000002c >>>> [ 0.282274] x17: 00000000000fd054 x16: 0000000000000000 >>>> [ 0.282276] x15: ffffff93b65ec000 x14: 000000000000000c >>>> [ 0.282279] x13: 0000000000000004 x12: 0000000000000000 >>>> [ 0.282281] x11: 0000000000000000 x10: 0000000001440144 >>>> [ 0.282283] x9 : 260822e8751d5000 x8 : 260822e8751d5000 >>>> [ 0.282286] x7 : 0000000000000000 x6 : fffffffbbac75b60 >>>> [ 0.282288] x5 : 0000000000000000 x4 : 0000000000000000 >>>> [ 0.282290] x3 : 000000003a657275 x2 : 0000000000000000 >>>> [ 0.282292] x1 : 0000000000000000 x0 : 000000000000000c >>>> [ 0.282294] >>>> [ 0.282294] PC: 0xffffff93b3f03d50: >>>> [ 0.282308] 3d50 b9001ac8 f94002c8 370ffec8 17ffffbe d4210000 14000= 000 aa1603e0 f90007e8 >>>> [ 0.282315] 3d70 94536017 f94007e8 17ffffe2 a9bf7bfd 910003fd d000d= 100 913ee400 94533cc7 >>>> [ 0.282322] 3d90 d4210000 14000000 b0013788 2a1f03e0 f901c51f d65f0= 3c0 f940406b 2a0203e8 >>>> [ 0.282329] 3db0 2a0103e9 aa0003ea b400008b f9000145 f94000cb b4000= 1ab a9bf7bfd 910003fd >>>> [ 0.282330] >>>> [ 0.282330] LR: 0xffffff93b3f03d50: >>>> [ 0.282336] 3d50 b9001ac8 f94002c8 370ffec8 17ffffbe d4210000 14000= 000 aa1603e0 f90007e8 >>>> [ 0.282343] 3d70 94536017 f94007e8 17ffffe2 a9bf7bfd 910003fd d000d= 100 913ee400 94533cc7 >>>> [ 0.282350] 3d90 d4210000 14000000 b0013788 2a1f03e0 f901c51f d65f0= 3c0 f940406b 2a0203e8 >>>> [ 0.282357] 3db0 2a0103e9 aa0003ea b400008b f9000145 f94000cb b4000= 1ab a9bf7bfd 910003fd >>>> [ 0.282358] >>>> [ 0.282358] SP: 0xfffffffbb30cfbf0: >>>> [ 0.282365] fbf0 b3f03d90 ffffff93 b30cfc30 fffffffb b3f03d90 fffff= f93 60c00085 00000000 >>>> [ 0.282372] fc10 b6415000 ffffff93 b642fa00 ffffff93 ffffffff fffff= fff b3f03d90 ffffff93 >>>> [ 0.282378] fc30 b30cfc70 fffffffb b3d458c0 ffffff93 00000080 00000= 000 00000001 00000000 >>>> [ 0.282385] fc50 b65c4000 ffffff93 b64420f0 ffffff93 8180e3e0 00000= 000 00000002 00000000 >>>> [ 0.282387] Process migration/2 (pid: 25, stack limit =3D 0xfffffffb= b30cc000) >>>> [ 0.282389] Call trace: >>>> [ 0.282391] Exception stack(0xfffffffbb30cfb00 to 0xfffffffbb30cfc30= ) >>>> [ 0.282395] fb00: 000000000000000c 0000000000000000 0000000000000000= 000000003a657275 >>>> [ 0.282397] fb20: 0000000000000000 0000000000000000 fffffffbbac75b60= 0000000000000000 >>>> [ 0.282400] fb40: 260822e8751d5000 260822e8751d5000 0000000001440144= 0000000000000000 >>>> [ 0.282403] fb60: 0000000000000000 0000000000000004 000000000000000c= ffffff93b65ec000 >>>> [ 0.282405] fb80: 0000000000000000 00000000000fd054 000000000000002c= 0000000000000000 >>>> [ 0.282408] fba0: 000000008180e3e0 9d12f8172cb2f296 ffffff93b65c4000= ffffff93b65c1000 >>>> [ 0.282411] fbc0: ffffff93b6419000 ffffff93b5ce6000 ffffff93b5ce6000= 00000013b65c1000 >>>> [ 0.282413] fbe0: ffffff93b6415000 fffffffbb30cfc30 ffffff93b3f03d90= fffffffbb30cfc30 >>>> [ 0.282416] fc00: ffffff93b3f03d90 0000000060c00085 ffffff93b6415000= ffffff93b642fa00 >>>> [ 0.282418] fc20: ffffffffffffffff ffffff93b3f03d90 >>>> [ 0.282421] [] __cfi_check_fail+0x14/0x1c >>>> [ 0.282430] [] name_to_dev_t+0x0/0x47c >>>> [ 0.282436] [] kpti_install_ng_mappings+0x178/0x2e= 0 >>>> [ 0.282443] [] multi_cpu_stop+0x114/0x170 >>>> [ 0.282445] [] cpu_stopper_thread+0x128/0x2e8 >>>> [ 0.282452] [] smpboot_thread_fn+0x230/0x558 >>>> [ 0.282455] [] kthread+0x21c/0x238 >>>> [ 0.282459] [] ret_from_fork+0x10/0x20 >>>> [ 0.282464] Code: 910003fd d000d100 913ee400 94533cc7 (d4210000) =20= >>>=20 >>> Oh fun :( >>>=20 >>> Dragging in a bunch more people to the cc: and to: lines to have them >>> look at this... >>>=20 >>> thanks, >>>=20 >>> greg k-h =20