From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Borislav Petkov <bp@alien8.de>,
David Woodhouse <dwmw2@infradead.org>,
Andi Kleen <andi@firstfloor.org>,
the arch/x86 maintainers <x86@kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Paul Turner <pjt@google.com>, Andrew Lutomirski <luto@kernel.org>,
Tom Lendacky <thomas.lendacky@amd.com>,
Tim Chen <tim.c.chen@linux.intel.com>,
Greg Kroah-Hartman <gregkh@linux-foundation.org>,
Dave Hansen <dave.hansen@intel.com>,
Jiri Kosina <jikos@kernel.org>, Andi Kleen <ak@linux.intel.com>
Subject: Re: [PATCH] x86/alternatives: Fix optimize_nops() checking
Date: Wed, 10 Jan 2018 21:33:52 +0100 [thread overview]
Message-ID: <20180110203352.GS6176@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CA+55aFzMzBwtfO1e=eC6oCx9mMMXPoRko0FvKKJrriUGqyQtEg@mail.gmail.com>
On Wed, Jan 10, 2018 at 12:26:25PM -0800, Linus Torvalds wrote:
> Imagine just how crazy that would be to debug. You'd be basically
> executing insane code, and looking at the sources - or even the
> binaries - it would _look_ completely sane.
Been there done that.. we have too much self modifying code for that
not to have been needed.
Use gdb on /proc/kcore and disassemble self to see the _real_ code.
But yes, tricky stuff. Not arguing we need relocations in alternatives,
just saying debugging them (and static keys and others) is great fun.
next prev parent reply other threads:[~2018-01-10 21:44 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-10 0:31 [PATCH] x86/retpoline: Fix NOSPEC_JMP for tip Andi Kleen
2018-01-10 0:39 ` Thomas Gleixner
2018-01-10 0:39 ` Linus Torvalds
2018-01-10 0:40 ` Thomas Gleixner
2018-01-10 0:45 ` Tom Lendacky
2018-01-10 0:50 ` Thomas Gleixner
2018-01-10 1:30 ` Andi Kleen
2018-01-10 1:36 ` Andi Kleen
2018-01-10 1:50 ` Thomas Gleixner
2018-01-10 1:57 ` Andi Kleen
2018-01-10 9:05 ` David Woodhouse
2018-01-10 0:51 ` Andi Kleen
2018-01-10 1:05 ` Thomas Gleixner
2018-01-10 7:15 ` David Woodhouse
2018-01-10 10:05 ` David Woodhouse
2018-01-10 11:28 ` [PATCH] x86/alternatives: Fix optimize_nops() checking Borislav Petkov
2018-01-10 11:36 ` David Woodhouse
2018-01-10 11:45 ` Borislav Petkov
2018-01-10 11:49 ` David Woodhouse
2018-01-10 11:57 ` Borislav Petkov
2018-01-10 11:58 ` David Woodhouse
2018-01-10 17:33 ` [tip:x86/pti] " tip-bot for Borislav Petkov
2018-01-10 18:12 ` tip-bot for Borislav Petkov
2018-01-10 18:39 ` tip-bot for Borislav Petkov
2018-01-10 19:38 ` [PATCH] " Linus Torvalds
2018-01-10 19:55 ` Thomas Gleixner
2018-01-10 20:15 ` Josh Poimboeuf
2018-01-10 20:19 ` David Woodhouse
2018-01-10 20:26 ` Linus Torvalds
2018-01-10 20:33 ` Peter Zijlstra [this message]
2018-01-10 20:36 ` David Woodhouse
2018-01-10 20:49 ` Linus Torvalds
2018-01-10 20:55 ` Borislav Petkov
2018-01-10 21:05 ` Linus Torvalds
2018-01-10 21:08 ` David Woodhouse
2018-01-10 21:11 ` Linus Torvalds
2018-01-10 21:16 ` Josh Poimboeuf
2018-01-10 21:17 ` Linus Torvalds
2018-01-10 21:27 ` Josh Poimboeuf
2018-01-10 21:10 ` Borislav Petkov
2018-01-10 20:55 ` Josh Poimboeuf
2018-01-10 20:05 ` Borislav Petkov
2018-01-10 20:20 ` Linus Torvalds
2018-01-10 20:50 ` Borislav Petkov
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