From: Peter Zijlstra <peterz@infradead.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
x86@kernel.org, joao@overdrivepizza.com, hjl.tools@gmail.com,
andrew.cooper3@citrix.com, linux-kernel@vger.kernel.org,
ndesaulniers@google.com, keescook@chromium.org,
samitolvanen@google.com, mark.rutland@arm.com,
alyssa.milburn@intel.com, Miroslav Benes <mbenes@suse.cz>,
Masami Hiramatsu <mhiramat@kernel.org>,
Alexei Starovoitov <alexei.starovoitov@gmail.com>
Subject: Re: [PATCH 04/29] x86/livepatch: Validate __fentry__ location
Date: Wed, 23 Feb 2022 16:54:14 +0100 [thread overview]
Message-ID: <YhZYpnlCQpz3m5ds@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <YhZJhSD3QyNSG/bP@hirez.programming.kicks-ass.net>
On Wed, Feb 23, 2022 at 03:49:41PM +0100, Peter Zijlstra wrote:
> > Since we would want rec->ip if the pointer is before the ftrace
> > instruction. But we would need to audit all use cases and make sure this is
> > not called from any hot paths (in a callback).
> >
> > This will affect kprobes and BPF as they both use ftrace_location() as well.
>
> Yes, I already fixed kprobes, still trying to (re)discover how to run
> the bpf-selftests, that stuff is too painful :-(
Ok, I think I managed... I'm obviously hitting the WARN_ON_ONCE() in
is_ftrace_location(). Funnily, no dead kernel, so that's something I
suppose.
Now, I'm trying to make sense of that code, but all that !ftrace_managed
code scares me to death.
At the very least __bpf_arch_text_poke() needs a bunch of help. Let me
go prod it with something sharp to see what falls out ...
next prev parent reply other threads:[~2022-02-23 15:54 UTC|newest]
Thread overview: 94+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-18 16:49 [PATCH 00/29] x86: Kernel IBT Peter Zijlstra
2022-02-18 16:49 ` [PATCH 01/29] static_call: Avoid building empty .static_call_sites Peter Zijlstra
2022-02-18 16:49 ` [PATCH 02/29] x86/module: Fix the paravirt vs alternative order Peter Zijlstra
2022-02-18 20:28 ` Josh Poimboeuf
2022-02-18 21:22 ` Peter Zijlstra
2022-02-18 23:28 ` Josh Poimboeuf
2022-02-18 16:49 ` [PATCH 03/29] objtool: Add --dry-run Peter Zijlstra
2022-02-18 16:49 ` [PATCH 04/29] x86/livepatch: Validate __fentry__ location Peter Zijlstra
2022-02-18 21:08 ` Josh Poimboeuf
2022-02-23 10:09 ` Peter Zijlstra
2022-02-23 10:21 ` Miroslav Benes
2022-02-23 10:57 ` Peter Zijlstra
2022-02-23 12:41 ` Steven Rostedt
2022-02-23 14:05 ` Peter Zijlstra
2022-02-23 14:16 ` Steven Rostedt
2022-02-23 14:23 ` Steven Rostedt
2022-02-23 14:33 ` Steven Rostedt
2022-02-23 14:49 ` Peter Zijlstra
2022-02-23 15:54 ` Peter Zijlstra [this message]
2022-02-18 16:49 ` [PATCH 05/29] x86: Base IBT bits Peter Zijlstra
2022-02-18 20:49 ` Andrew Cooper
2022-02-18 21:11 ` David Laight
2022-02-18 21:24 ` Andrew Cooper
2022-02-18 22:37 ` David Laight
2022-02-18 21:26 ` Peter Zijlstra
2022-02-18 21:14 ` Josh Poimboeuf
2022-02-18 21:21 ` Peter Zijlstra
2022-02-18 22:12 ` Joao Moreira
2022-02-19 1:07 ` Edgecombe, Rick P
2022-02-18 16:49 ` [PATCH 06/29] x86/ibt: Add ANNOTATE_NOENDBR Peter Zijlstra
2022-02-18 16:49 ` [PATCH 07/29] x86/entry: Sprinkle ENDBR dust Peter Zijlstra
2022-02-19 0:23 ` Josh Poimboeuf
2022-02-19 23:08 ` Peter Zijlstra
2022-02-19 0:36 ` Josh Poimboeuf
2022-02-18 16:49 ` [PATCH 08/29] x86/linkage: Add ENDBR to SYM_FUNC_START*() Peter Zijlstra
2022-02-18 16:49 ` [PATCH 09/29] x86/ibt,paravirt: Sprinkle ENDBR Peter Zijlstra
2022-02-18 16:49 ` [PATCH 10/29] x86/bpf: Add ENDBR instructions to prologue Peter Zijlstra
2022-02-18 16:49 ` [PATCH 11/29] x86/ibt,crypto: Add ENDBR for the jump-table entries Peter Zijlstra
2022-02-18 16:49 ` [PATCH 12/29] x86/ibt,kvm: Add ENDBR to fastops Peter Zijlstra
2022-02-18 16:49 ` [PATCH 13/29] x86/ibt,ftrace: Add ENDBR to samples/ftrace Peter Zijlstra
2022-02-18 16:49 ` [PATCH 14/29] x86/ibt: Add IBT feature, MSR and #CP handling Peter Zijlstra
2022-02-18 19:31 ` Andrew Cooper
2022-02-18 21:15 ` Peter Zijlstra
2022-02-19 1:20 ` Edgecombe, Rick P
2022-02-19 1:21 ` Josh Poimboeuf
2022-02-19 9:24 ` Peter Zijlstra
2022-02-21 8:24 ` Kees Cook
2022-02-22 4:38 ` Edgecombe, Rick P
2022-02-22 9:32 ` Peter Zijlstra
2022-02-18 16:49 ` [PATCH 15/29] x86: Disable IBT around firmware Peter Zijlstra
2022-02-21 8:27 ` Kees Cook
2022-02-21 10:06 ` Peter Zijlstra
2022-02-21 13:22 ` Peter Zijlstra
2022-02-21 15:54 ` Kees Cook
2022-02-21 16:10 ` Peter Zijlstra
2022-02-18 16:49 ` [PATCH 16/29] x86/bugs: Disable Retpoline when IBT Peter Zijlstra
2022-02-19 2:15 ` Josh Poimboeuf
2022-02-22 15:00 ` Peter Zijlstra
2022-02-25 0:19 ` Josh Poimboeuf
2022-02-18 16:49 ` [PATCH 17/29] x86/ibt: Annotate text references Peter Zijlstra
2022-02-19 5:22 ` Josh Poimboeuf
2022-02-19 9:39 ` Peter Zijlstra
2022-02-18 16:49 ` [PATCH 18/29] x86/ibt,ftrace: Annotate ftrace code patching Peter Zijlstra
2022-02-18 16:49 ` [PATCH 19/29] x86/ibt,xen: Annotate away warnings Peter Zijlstra
2022-02-18 20:24 ` Andrew Cooper
2022-02-18 21:05 ` Peter Zijlstra
2022-02-18 23:07 ` Andrew Cooper
2022-02-21 14:20 ` Peter Zijlstra
2022-02-18 16:49 ` [PATCH 20/29] x86/ibt,sev: Annotations Peter Zijlstra
2022-02-18 16:49 ` [PATCH 21/29] objtool: Rename --duplicate to --lto Peter Zijlstra
2022-02-26 19:42 ` Josh Poimboeuf
2022-02-26 21:48 ` Josh Poimboeuf
2022-02-28 11:05 ` Peter Zijlstra
2022-02-28 18:32 ` Josh Poimboeuf
2022-02-28 20:09 ` Peter Zijlstra
2022-02-28 20:18 ` Josh Poimboeuf
2022-03-01 14:19 ` Miroslav Benes
2022-02-18 16:49 ` [PATCH 22/29] Kbuild: Prepare !CLANG whole module objtool Peter Zijlstra
2022-02-18 16:49 ` [PATCH 23/29] objtool: Read the NOENDBR annotation Peter Zijlstra
2022-02-18 16:49 ` [PATCH 24/29] x86/text-patching: Make text_gen_insn() IBT aware Peter Zijlstra
2022-02-24 1:18 ` Joao Moreira
2022-02-24 9:10 ` Peter Zijlstra
2022-02-18 16:49 ` [PATCH 25/29] x86/ibt: Dont generate ENDBR in .discard.text Peter Zijlstra
2022-02-18 16:49 ` [PATCH 26/29] objtool: Add IBT validation / fixups Peter Zijlstra
2022-02-18 16:49 ` [PATCH 27/29] x86/ibt: Finish --ibt-fix-direct on module loading Peter Zijlstra
2022-02-18 16:49 ` [PATCH 28/29] x86/ibt: Ensure module init/exit points have references Peter Zijlstra
2022-02-18 16:49 ` [PATCH 29/29] x86/alternative: Use .ibt_endbr_sites to seal indirect calls Peter Zijlstra
2022-02-19 1:29 ` [PATCH 00/29] x86: Kernel IBT Edgecombe, Rick P
2022-02-19 9:58 ` Peter Zijlstra
2022-02-19 16:00 ` Andrew Cooper
2022-02-21 8:42 ` Kees Cook
2022-02-21 9:24 ` Peter Zijlstra
2022-02-23 7:26 ` Kees Cook
2022-02-24 16:47 ` Mike Rapoport
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=YhZYpnlCQpz3m5ds@hirez.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=alexei.starovoitov@gmail.com \
--cc=alyssa.milburn@intel.com \
--cc=andrew.cooper3@citrix.com \
--cc=hjl.tools@gmail.com \
--cc=joao@overdrivepizza.com \
--cc=jpoimboe@redhat.com \
--cc=keescook@chromium.org \
--cc=linux-kernel@vger.kernel.org \
--cc=mark.rutland@arm.com \
--cc=mbenes@suse.cz \
--cc=mhiramat@kernel.org \
--cc=ndesaulniers@google.com \
--cc=rostedt@goodmis.org \
--cc=samitolvanen@google.com \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.