From: Torsten Duwe <duwe@lst•de>
To: Kamalesh Babulal <kamalesh@linux•vnet.ibm.com>
Cc: Michael Ellerman <mpe@ellerman•id.au>,
Balbir Singh <bsingharora@gmail•com>,
"Naveen N . Rao" <naveen.n.rao@linux•vnet.ibm.com>,
Josh Poimboeuf <jpoimboe@redhat•com>,
Jessica Yu <jeyu@kernel•org>,
Ananth N Mavinakayanahalli <ananth@linux•vnet.ibm.com>,
Aravinda Prasad <aravinda@linux•vnet.ibm.com>,
linuxppc-dev@lists•ozlabs.org, live-patching@vger•kernel.org
Subject: Re: [PATCH v2] kernel/module_64.c: Add REL24 relocation support of livepatch symbols
Date: Fri, 20 Oct 2017 14:07:39 +0200 [thread overview]
Message-ID: <20171020120739.GA20306@lst.de> (raw)
In-Reply-To: <95e6f942-88b7-0208-0eb0-2f5462aec410@linux.vnet.ibm.com>
On Wed, Oct 18, 2017 at 11:47:35AM +0530, Kamalesh Babulal wrote:
>
> Consider a trivial patch, supplied to kpatch tool for generating a
> livepatch module:
>
> --- a/fs/proc/meminfo.c
> +++ b/fs/proc/meminfo.c
> @@ -132,7 +132,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
> seq_printf(m, "VmallocTotal: %8lu kB\n",
> (unsigned long)VMALLOC_TOTAL >> 10);
> show_val_kb(m, "VmallocUsed: ", 0ul);
> - show_val_kb(m, "VmallocChunk: ", 0ul);
> + show_val_kb(m, "VMALLOCCHUNK: ", 0ul);
>
Am I assuming correctly that "kpatch tool" simply recompiles all code the
way it would get compiled in a regular kernel build? My understanding is
that live patching modules need to be carefully prepared, which involves
source code reorganisation and recompilation. In that process, you can
easily declare show_val_kb() extern, and get the suitable instruction sequence
for the call.
You have CC'ed live-patching. A discussion about how to automate this very
process is currently going on there. May I suggest you subscribe to that if
you are interested.
Torsten
next prev parent reply other threads:[~2017-10-20 12:07 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-04 15:25 [PATCH v2] kernel/module_64.c: Add REL24 relocation support of livepatch symbols Kamalesh Babulal
2017-10-05 6:56 ` Naveen N . Rao
2017-10-05 12:43 ` Torsten Duwe
2017-10-06 5:43 ` Kamalesh Babulal
2017-10-11 9:44 ` Kamalesh Babulal
2017-10-06 5:57 ` Kamalesh Babulal
2017-10-17 14:47 ` Torsten Duwe
2017-10-18 6:17 ` Kamalesh Babulal
2017-10-20 12:07 ` Torsten Duwe [this message]
2017-10-21 0:59 ` Balbir Singh
2017-10-23 8:19 ` Kamalesh Babulal
2017-12-12 11:39 ` [PATCH] On ppc64le we HAVE_RELIABLE_STACKTRACE Torsten Duwe
2017-12-12 12:12 ` Miroslav Benes
2017-12-12 13:02 ` Torsten Duwe
2018-02-27 16:09 ` [PATCH 2/2] ppc64le save_stack_trace_tsk_reliable (Was: HAVE_RELIABLE_STACKTRACE) Torsten Duwe
2018-03-08 21:43 ` Balbir Singh
2018-03-09 15:54 ` Torsten Duwe
2017-12-12 14:05 ` [PATCH] On ppc64le we HAVE_RELIABLE_STACKTRACE Josh Poimboeuf
2017-12-15 9:40 ` Nicholas Piggin
2017-12-18 2:58 ` Josh Poimboeuf
2017-12-18 3:39 ` Balbir Singh
2017-12-18 4:01 ` Josh Poimboeuf
2017-12-18 5:33 ` Nicholas Piggin
2017-12-18 18:56 ` Josh Poimboeuf
2017-12-19 2:46 ` Nicholas Piggin
2017-12-19 11:28 ` Torsten Duwe
2017-12-19 21:46 ` Josh Poimboeuf
2017-12-21 12:10 ` Michael Ellerman
2017-12-23 4:00 ` Josh Poimboeuf
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