From: Christoph Hellwig <hch@infradead.org>
To: Peter Zijlstra <peterz@infradead.org>
Cc: Andy Lutomirski <luto@kernel.org>,
x86@kernel.org, LKML <linux-kernel@vger.kernel.org>,
Dave Hansen <dave.hansen@linux.intel.com>,
Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Yonghong Song <yhs@fb.com>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [RFC][PATCH] kprobes: Remove kprobe::fault_handler
Date: Wed, 10 Feb 2021 19:09:18 +0000 [thread overview]
Message-ID: <20210210190918.GA2208287@infradead.org> (raw)
In-Reply-To: <YCPmL45wQSyWLmst@hirez.programming.kicks-ass.net>
On Wed, Feb 10, 2021 at 02:57:03PM +0100, Peter Zijlstra wrote:
>
> Somewhat related.. I had this pending.
>
> ---
> Subject: kprobes: Remove kprobe::fault_handler
> From: Peter Zijlstra <peterz@infradead.org>
> Date: Tue Feb 2 10:43:41 CET 2021
>
> The reason for kprobe::fault_handler(), as given by their comment:
>
> * We come here because instructions in the pre/post
> * handler caused the page_fault, this could happen
> * if handler tries to access user space by
> * copy_from_user(), get_user() etc. Let the
> * user-specified handler try to fix it first.
>
> If just plain bad. Those other handlers are ran from non-preemptible
> context and had better use _nofault() functions. Also, there is no
> upstream usage of this.
>
> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
next prev parent reply other threads:[~2021-02-10 19:10 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-10 2:33 [PATCH v2 00/14] x86/fault: #PF improvements, mostly related to USER bit Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 01/14] x86/fault: Fix AMD erratum #91 errata fixup for user code Andy Lutomirski
2021-02-10 7:34 ` Christoph Hellwig
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 02/14] x86/fault: Skip the AMD erratum #91 workaround on unaffected CPUs Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 03/14] x86/fault: Fold mm_fault_error() into do_user_addr_fault() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 04/14] x86/fault/32: Move is_f00f_bug() to do_kern_addr_fault() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 05/14] x86/fault: Document the locking in the fault_signal_pending() path Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 06/14] x86/fault: Correct a few user vs kernel checks wrt WRUSS Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 07/14] x86/fault: Improve kernel-executing-user-memory handling Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 08/14] x86/fault: Skip erratum #93 workaround on new CPUs Andy Lutomirski
2021-02-10 6:06 ` Andy Lutomirski
2021-02-10 13:29 ` Borislav Petkov
2021-02-10 16:09 ` Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 09/14] x86/fault: Split the OOPS code out from no_context() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 10/14] x86/fault: Bypass no_context() for implicit kernel faults from usermode Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 11/14] x86/fault: Rename no_context() to kernelmode_fixup_or_oops() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 12/14] x86/fault: Don't look for extable entries for SMEP violations Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 13/14] x86/fault: Don't run fixups for SMAP violations Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] " tip-bot2 for Andy Lutomirski
2021-02-10 2:33 ` [PATCH v2 14/14] x86/fault, x86/efi: Fix and rename efi_recover_from_page_fault() Andy Lutomirski
2021-02-10 17:45 ` [tip: x86/mm] x86/{fault,efi}: " tip-bot2 for Andy Lutomirski
2021-02-11 8:38 ` [PATCH v2 14/14] x86/fault, x86/efi: " Ard Biesheuvel
2021-02-10 13:57 ` [RFC][PATCH] kprobes: Remove kprobe::fault_handler Peter Zijlstra
2021-02-10 19:09 ` Christoph Hellwig [this message]
2021-02-10 19:47 ` Alexei Starovoitov
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=20210210190918.GA2208287@infradead.org \
--to=hch@infradead.org \
--cc=ast@kernel.org \
--cc=daniel@iogearbox.net \
--cc=dave.hansen@linux.intel.com \
--cc=linux-kernel@vger.kernel.org \
--cc=luto@kernel.org \
--cc=mhiramat@kernel.org \
--cc=peterz@infradead.org \
--cc=x86@kernel.org \
--cc=yhs@fb.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®