Re: [PATCH 5.18 000/231] 5.18.13-rc1 review
From: Jiri Slaby
Date: Thu Jul 21 2022 - 02:08:01 EST
On 21. 07. 22, 7:31, Jiri Slaby wrote:
On 21. 07. 22, 0:00, Peter Zijlstra wrote:
On Wed, Jul 20, 2022 at 11:47:02PM +0200, Peter Zijlstra wrote:
On Wed, Jul 20, 2022 at 12:57:26PM -0500, Justin Forbes wrote:
On Wed, Jul 20, 2022 at 10:28:33AM -0700, Linus Torvalds wrote:
[ Adding PeterZ and Jiri to the participants. ]
Looks like 5.18.13 added that commit 9bb2ec608a20 ("objtool: Update
Retpoline validation") but I don't see 3131ef39fb03 ("x86/asm/32: Fix
ANNOTATE_UNRET_SAFE use on 32-bit") in that list.
It should be noted that the build doesn't fail, it just warns.
I am guessing the 32bit failure is what promoted someone to look at
the logs to begin with and notice the warn initially. I just verified
that it exists in our builds of 5.18.13-rc1, but not on mainline
builds.
I am gueesing it is because commit 9bb2ec608a20 ("objtool: Update
Retpoline
validation") should be followed up with at least commit f43b9876e857c
("x86/retbleed: Add fine grained Kconfig knobs")
Still updateing the stable repro to see what the actual code looks like,
but that warning seems to suggest the -mfunction-return=thunk-extern
compiler argument went missing.
For all the files objtool complains about, does the V=1 build output
show that option?
Ok, I'm now looking at stable-rc/linux-5.18.y which reports itself as:
VERSION = 5
PATCHLEVEL = 18
SUBLEVEL = 13
EXTRAVERSION = -rc1
and I'm most terribly confused... it has the objtool patch to validate
return thunks, *however*, I'm not seeing any actual retbleed mitigations
*anywhere*.
How, what, why!?
They were all put aside until all this gets resolved. You can find them
in the stable-queue tree:
git://git.kernel.org/pub/scm/linux/kernel/git/stable/stable-queue.git
in retbleed-5.18/.
Ah, apparently not all, as you noted above. But this is obviously a mistake:
https://lore.kernel.org/all/YthbbBY4JumsBcHU@xxxxxxxxx/
regards,--
--
js
suse labs