Date: Thu, 26 Sep 2019 20:29:24 +0300 From: Konstantin Belousov <kostikbel@gmail.com> To: Alan Somers <asomers@freebsd.org> Cc: FreeBSD CURRENT <freebsd-current@freebsd.org> Subject: Re: panic: Unregistered use of FPU in kernel Message-ID: <20190926172924.GH44691@kib.kiev.ua> In-Reply-To: <CAOtMX2jTS%2Bu-Kw6=5oYQadnDBOBrVqH0Mvb-S8TNLcaswLgNSQ@mail.gmail.com> References: <CAOtMX2gLM8uWuQEz3jq2S3i7BfhUq=y6EH4MCchdJDmnzRqGsA@mail.gmail.com> <20190926170241.GG44691@kib.kiev.ua> <CAOtMX2jTS%2Bu-Kw6=5oYQadnDBOBrVqH0Mvb-S8TNLcaswLgNSQ@mail.gmail.com>
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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.home | help
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