From owner-freebsd-current@freebsd.org Thu Sep 26 20:19:20 2019 Return-Path: Delivered-To: freebsd-current@mailman.nyi.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.nyi.freebsd.org (Postfix) with ESMTP id AEB6A1332CC for ; Thu, 26 Sep 2019 20:19:20 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: from mail-io1-f65.google.com (mail-io1-f65.google.com [209.85.166.65]) (using TLSv1.3 with cipher TLS_AES_128_GCM_SHA256 (128/128 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (2048 bits) client-digest SHA256) (Client CN "smtp.gmail.com", Issuer "GTS CA 1O1" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 46fR9446GGz3QHC; Thu, 26 Sep 2019 20:19:20 +0000 (UTC) (envelope-from cse.cem@gmail.com) Received: by mail-io1-f65.google.com with SMTP id c25so9883593iot.12; Thu, 26 Sep 2019 13:19:20 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:reply-to :from:date:message-id:subject:to:cc; bh=yY6i3UGdF1bJpy1dTyM8hzkHR0chMGwdC7alEFO3InA=; b=IgX0/dJeshz49vDuPpLSFwtKHSBWUBbAi1wMVDEnDz4xE3yvjrBGF6PXLZ8BI+Newf upf4MHMcFiKeTbn98mUx86Vzktw3ZzgKx6yVHqY9InWVYS2Mjeoy1sY6Orzfgp5HCyCC mG9gN/9O0RpNKudHzYEKaD0MPs3e6/XmS4XZS8JQ37R//MV1KffZ/GHChMj0ry1FgeSY KCSCWBKlBNFa7qOao+k6dq7P2VNFY3ythvm8qzTyS/mnpHEWjeKBHKpxI/gVlNM7VVjy 3C3pKJim8F09Zs47MWahpGidEy9bYj4tb6KkPrBiFb9XaPUbbgwZ31cZOF8htoZ0ky3M G6hg== X-Gm-Message-State: APjAAAWvVHI3IOwK2RGbLWcGxC9e3vEk8vAW4j/r7Qe/ynOKLOCrK+L3 w/ErKvnY79IuuRb9nolqp8rFSher X-Google-Smtp-Source: APXvYqws9lQWTSvtdWRvjaxHhY/pmvBYFOqMYGjNxrOWJlP15iaDzidVUKWDcb8N820b2dvw/iQ6xw== X-Received: by 2002:a92:15c4:: with SMTP id 65mr518354ilv.173.1569529159258; Thu, 26 Sep 2019 13:19:19 -0700 (PDT) Received: from mail-io1-f42.google.com (mail-io1-f42.google.com. [209.85.166.42]) by smtp.gmail.com with ESMTPSA id w16sm174437ilc.62.2019.09.26.13.19.17 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 26 Sep 2019 13:19:17 -0700 (PDT) Received: by mail-io1-f42.google.com with SMTP id b19so9999863iob.4; Thu, 26 Sep 2019 13:19:17 -0700 (PDT) X-Received: by 2002:a05:6602:2185:: with SMTP id b5mr5100308iob.265.1569529157488; Thu, 26 Sep 2019 13:19:17 -0700 (PDT) MIME-Version: 1.0 References: <20190926170241.GG44691@kib.kiev.ua> <20190926172924.GH44691@kib.kiev.ua> In-Reply-To: Reply-To: cem@freebsd.org From: Conrad Meyer Date: Thu, 26 Sep 2019 13:19:06 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: panic: Unregistered use of FPU in kernel To: Alan Somers Cc: Konstantin Belousov , FreeBSD CURRENT Content-Type: text/plain; charset="UTF-8" X-Rspamd-Queue-Id: 46fR9446GGz3QHC X-Spamd-Bar: ----- Authentication-Results: mx1.freebsd.org; none X-Spamd-Result: default: False [-6.00 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; REPLY(-4.00)[]; TAGGED_FROM(0.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000,0] X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 26 Sep 2019 20:19:20 -0000 This kinda just looks like ddb doesn't know how to disassemble crc32q? Which might not be too surprising. Note that it also truncates the qword constant in "add" at +167/+0xa7. That one isn't corruption; just a DDB bug. Can you print the faulting %rip and dump a few bytes at that address in both ddb and gdb (assuming ddb can't disassemble crc32q)? Best, Conrad On Thu, Sep 26, 2019 at 1:12 PM Alan Somers wrote: > > On Thu, Sep 26, 2019 at 11:29 AM Konstantin Belousov > wrote: > > > On Thu, Sep 26, 2019 at 11:20:51AM -0600, Alan Somers wrote: > > > On Thu, Sep 26, 2019 at 11:02 AM Konstantin Belousov < > > kostikbel@gmail.com> > > > wrote: > > > > > > > On Thu, Sep 26, 2019 at 09:45:43AM -0600, Alan Somers wrote: > > > > > The latest VM snapshot > > > > (FreeBSD-13.0-CURRENT-amd64-20190920-r352544.qcow2) > > > > > instapanics on boot: > > > > > > > > > > panic: Unregistered use of FPU in kernel > > > > > > > > > > stack trace: > > > > > ... > > > > > sse42_crc32c > > > > > readsuper > > > > > ffs_sbget > > > > > g_label_ufs_taste_common > > > > > g_label_taste > > > > > g_new_provider_event > > > > > g_run_events > > > > > fork_exit > > > > > ... > > > > > > > > > > Has anybody touched this area recently? I'll try to narrow down the > > > > commit > > > > > range. > > > > > > > > Start with disassembling the faulting instruction. I suspect that > > somehow > > > > vital compiler switches like -mno-sse got omitted in the build. > > > > > > > > > > No problem with compiler switches here. The C file uses inline assembly > > to > > > generate a crc32q instruction, in crc32_sse42.c:257. But why would that > > > generate a floating point exception? The instruction doesn't appear to > > be > > > using any floating point registers. This is on a Kaby Lake CPU. > > > > > > crc32q %rsi, %rbx > > > > No idea, this instruction does not generate #NP at all. > > > > Provide exact script of the panic and backtrace, > > together with the disassembly of the function which contained the faulted > > instruction. Do disassemble from ddb, in case text was corrupted. > > > > Ok, here's the full stack trace: > #0 __curthread () at /usr/src/sys/amd64/include/pcpu_aux.h:55 > #1 doadump (textdump=0) at /usr/src/sys/kern/kern_shutdown.c:392 > #2 0xffffffff804a1edb in db_dump (dummy=, > dummy2=, dummy3=, dummy4=) > at /usr/src/sys/ddb/db_command.c:575 > #3 0xffffffff804a1c8f in db_command (last_cmdp=, > cmd_table=, dopager=1) at > /usr/src/sys/ddb/db_command.c:482 > #4 0xffffffff804a1a04 in db_command_loop () > at /usr/src/sys/ddb/db_command.c:535 > #5 0xffffffff804a4cbf in db_trap (type=, code= out>) > at /usr/src/sys/ddb/db_main.c:252 > #6 0xffffffff80c1e55c in kdb_trap (type=3, code=0, tf=) > at /usr/src/sys/kern/subr_kdb.c:692 > #7 0xffffffff811957df in trap (frame=0xfffffe00907e8d20) > at /usr/src/sys/amd64/amd64/trap.c:621 > #8 > > Your guess about corrupted text was prescient. Here is the disassembly > according to ddb: > https://people.freebsd.org/~asomers/Screenshot_fbsd-head_2019-09-26_13%3A51%3A34.png > And here is the disassembly of the same section according to gdb: > 0xffffffff8113b2e0 : mov %rsi,%r9 > 0xffffffff8113b2e3 : sub $0xffffffffffffff80,%r9 > 0xffffffff8113b2e7 : add $0x100,%rsi > 0xffffffff8113b2ee : mov %r11,%rbx > 0xffffffff8113b2f1 : xor %eax,%eax > 0xffffffff8113b2f3 : xor %r11d,%r11d > 0xffffffff8113b2f6 : nopw %cs:0x0(%rax,%rax,1) > 0xffffffff8113b300 : mov %rsi,%rdx > 0xffffffff8113b303 : mov -0x100(%rsi),%rsi > 0xffffffff8113b30a : mov -0x80(%rdx),%rdi > 0xffffffff8113b30e : crc32q %rsi,%rbx > 0xffffffff8113b314 : crc32q %rdi,%rax > 0xffffffff8113b31a : mov (%rdx),%rsi > 0xffffffff8113b31d : crc32q %rsi,%r11 > 0xffffffff8113b323 : lea 0x8(%rdx),%rsi > 0xffffffff8113b327 : add $0xffffffffffffff08,%rdx > 0xffffffff8113b32e : cmp %r9,%rdx > 0xffffffff8113b331 : > jb 0xffffffff8113b300 > 0xffffffff8113b333 : movzbl %cl,%r9d > 0xffffffff8113b337 : movzbl %ch,%edi > 0xffffffff8113b33a : mov %ecx,%edx > > Care to guess what's causing the corruption? > -Alan > _______________________________________________ > freebsd-current@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscribe@freebsd.org"