From: Ondrej Zary <linux@zary.sk>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>,
"the arch/x86 maintainers" <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] x86/iopl: Fake iopl(3) CLI/STI usage
Date: Sat, 18 Sep 2021 17:53:55 +0200 [thread overview]
Message-ID: <202109181753.55995.linux@zary.sk> (raw)
In-Reply-To: <20210918090641.GD5106@worktop.programming.kicks-ass.net>
On Saturday 18 September 2021 11:06:41 Peter Zijlstra wrote:
> On Sat, Sep 18, 2021 at 09:05:28AM +0200, Peter Zijlstra wrote:
> > On Fri, Sep 17, 2021 at 03:24:51PM -0700, Linus Torvalds wrote:
> > > On Fri, Sep 17, 2021 at 3:23 PM Linus Torvalds
> > > <torvalds@linux-foundation.org> wrote:
> > > >
> > > > I think the proper thing to do is perhaps something like
> > >
> > > The alternative is to just ignore cs_abse entirely, and just use
> > > "regs->ip", which makes this all even easier.
> > >
> > > If somebody uses a code segment _and_ cli/sti, maybe they should just
> > > get the SIGSEGV?
> >
> > I did a hatched job on fixup_ump_exception() which is why it looks like
> > it does, that said...
> >
> > our case at hand mmap()'s BIOS code from /dev/mem and executes that, I
> > don't think it does an LDT segment but it would be entirely in line with
> > the level of hack we're looking at.
> >
> > Let me frob at this after breakfast and see if I can make it better.
>
> How's this then? I should probably look to see if I should be using this
> insn_get_effective_ip() for perf_instruction_pointer() too. Although I
> suspect we maybe took a shortcut there in favour of performance.
Good for me because it works.
# dmesg | tail
[ 7.229031] Console: switching to colour frame buffer device 128x48
[ 7.234234] atyfb: fb0: ATY Mach64 frame buffer device on PCI
[ 7.929907] random: crng init done
[ 7.929913] random: 7 urandom warning(s) missed due to ratelimiting
[ 8.441701] process 'hp/hp-health/bin/hpasmd' started with executable stack
[ 8.638998] traps: hpasmd[360] attempts to use CLI/STI, pretending it's a NOP, ip:f7cb109b in mem[f7cb1000+3000]
[ 10.253851] floppy0: no floppy controllers found
[ 16.413225] tg3 0000:03:01.0 enp3s1f0: Link is up at 1000 Mbps, full duplex
[ 16.413257] tg3 0000:03:01.0 enp3s1f0: Flow control is on for TX and on for RX
[ 16.414645] IPv6: ADDRCONF(NETDEV_CHANGE): enp3s1f0: link becomes ready
root@edi2:/home/edi# hpasmcli -s "show fans"
Fan Location Present Speed of max Redundant Partner Hot-pluggable
--- -------- ------- ----- ------ --------- ------- -------------
#1 PROCESSOR_ZONE Yes NORMAL 22% Yes 2 Yes
#2 PROCESSOR_ZONE Yes NORMAL 22% Yes 1 Yes
#3 I/O_ZONE Yes NORMAL 11% Yes 1 Yes
#4 I/O_ZONE Yes NORMAL 11% Yes 1 Yes
#5 PROCESSOR_ZONE Yes NORMAL 22% Yes 1 Yes
#6 PROCESSOR_ZONE Yes NORMAL 22% Yes 1 Yes
#7 POWERSUPPLY_BAY Yes NORMAL 11% Yes 1 Yes
#8 POWERSUPPLY_BAY Yes NORMAL 11% Yes 1 Yes
--
Ondrej Zary
next prev parent reply other threads:[~2021-09-18 15:54 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 12:23 IOPL emulation breaks hpasmd (hp-health) needed by HP DL380 G4 servers Ondrej Zary
2021-09-16 17:09 ` Thomas Gleixner
2021-09-16 20:27 ` Ondrej Zary
2021-09-16 21:05 ` Peter Zijlstra
2021-09-17 8:11 ` Ondrej Zary
2021-09-17 9:20 ` [PATCH] x86/iopl: Fake iopl(3) CLI/STI usage Peter Zijlstra
2021-09-17 10:29 ` Ondrej Zary
2021-09-17 11:54 ` Peter Zijlstra
2021-09-17 12:33 ` Thomas Gleixner
2021-09-17 12:54 ` Ondrej Zary
2021-09-17 10:40 ` Thomas Gleixner
2021-09-17 22:23 ` Linus Torvalds
2021-09-17 22:24 ` Linus Torvalds
2021-09-18 7:05 ` Peter Zijlstra
2021-09-18 9:06 ` Peter Zijlstra
2021-09-18 15:53 ` Ondrej Zary [this message]
2021-09-18 16:35 ` Linus Torvalds
2021-09-21 7:28 ` [tip: x86/core] " tip-bot2 for Peter Zijlstra
2021-09-21 11:09 ` Ondrej Zary
2021-09-21 12:00 ` Peter Zijlstra
2021-09-21 17:31 ` Ondrej Zary
2021-09-21 12:41 ` tip-bot2 for Peter Zijlstra
2021-09-21 21:01 ` [PATCH] " Andy Lutomirski
2021-09-16 21:25 ` IOPL emulation breaks hpasmd (hp-health) needed by HP DL380 G4 servers Thomas Gleixner
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