From: Josh Poimboeuf <jpoimboe@redhat.com>
To: Joe Lawrence <joe.lawrence@redhat.com>
Cc: live-patching@vger.kernel.org, linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Jessica Yu <jeyu@kernel.org>
Subject: Re: [PATCH v2 2/9] livepatch: Apply vmlinux-specific KLP relocations early
Date: Mon, 20 Apr 2020 14:51:11 -0500 [thread overview]
Message-ID: <20200420195111.ob7jnhs7wqp6d56g@treble> (raw)
In-Reply-To: <20200420194900.GC13807@redhat.com>
On Mon, Apr 20, 2020 at 03:49:00PM -0400, Joe Lawrence wrote:
> On Mon, Apr 20, 2020 at 02:11:17PM -0500, Josh Poimboeuf wrote:
> > On Mon, Apr 20, 2020 at 03:01:41PM -0400, Joe Lawrence wrote:
> > > > > ... apply_relocations() is also iterating over the section headers (the
> > > > > diff context doesn't show it here, but i is an incrementing index over
> > > > > sechdrs[]).
> > > > >
> > > > > So if there is more than one KLP relocation section, we'll process them
> > > > > multiple times. At least the x86 relocation code will detect this and
> > > > > fail the module load with an invalid relocation (existing value not
> > > > > zero).
> > > >
> > > > Ah, yes, good catch!
> > > >
> > >
> > > The same test case passed with a small modification to push the foreach
> > > KLP section part to a kernel/livepatch/core.c local function and
> > > exposing the klp_resolve_symbols() + apply_relocate_add() for a given
> > > section to kernel/module.c. Something like following...
> >
> > I came up with something very similar, though I named them
> > klp_apply_object_relocs() and klp_apply_section_relocs() and changed the
> > argument order a bit (module first). Since it sounds like you have a
> > test, could you try this one?
> >
>
> LGTM. I have a few klp-convert selftests that I've been slowly
> tinkering on and they all load/run successfully with this version. :)
Good to hear, thanks! Hooray selftests :-)
--
Josh
next prev parent reply other threads:[~2020-04-20 19:51 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-04-17 14:04 [PATCH v2 0/9] livepatch,module: Remove .klp.arch and module_disable_ro() Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 1/9] livepatch: Disallow vmlinux.ko Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 2/9] livepatch: Apply vmlinux-specific KLP relocations early Josh Poimboeuf
2020-04-20 17:57 ` Joe Lawrence
2020-04-20 18:25 ` Josh Poimboeuf
2020-04-20 19:01 ` Joe Lawrence
2020-04-20 19:11 ` Josh Poimboeuf
2020-04-20 19:49 ` Joe Lawrence
2020-04-20 19:51 ` Josh Poimboeuf [this message]
2020-04-23 1:10 ` Joe Lawrence
2020-04-21 11:54 ` Miroslav Benes
2020-04-17 14:04 ` [PATCH v2 3/9] livepatch: Remove .klp.arch Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 4/9] livepatch: Prevent module-specific KLP rela sections from referencing vmlinux symbols Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 5/9] s390: Change s390_kernel_write() return type to match memcpy() Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 6/9] s390/module: Use s390_kernel_write() for late relocations Josh Poimboeuf
2020-04-22 12:28 ` Miroslav Benes
2020-04-24 13:43 ` Josh Poimboeuf
2020-04-22 14:40 ` Gerald Schaefer
2020-04-22 15:21 ` Gerald Schaefer
2020-04-22 19:46 ` Josh Poimboeuf
2020-04-23 12:33 ` Gerald Schaefer
2020-04-23 13:22 ` Miroslav Benes
2020-04-23 14:12 ` Josh Poimboeuf
2020-04-23 18:10 ` Josh Poimboeuf
2020-04-23 23:26 ` Josh Poimboeuf
2020-04-24 2:35 ` Joe Lawrence
2020-04-24 4:12 ` Josh Poimboeuf
2020-04-24 7:20 ` Christian Borntraeger
2020-04-24 13:37 ` Josh Poimboeuf
2020-04-30 14:38 ` Joe Lawrence
2020-04-30 16:48 ` Josh Poimboeuf
2020-04-30 17:04 ` Joe Lawrence
2020-04-23 14:21 ` Joe Lawrence
2020-04-17 14:04 ` [PATCH v2 7/9] x86/module: Use text_poke() " Josh Poimboeuf
2020-04-17 14:29 ` Peter Zijlstra
2020-04-17 14:51 ` Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 8/9] livepatch: Remove module_disable_ro() usage Josh Poimboeuf
2020-04-17 14:04 ` [PATCH v2 9/9] module: Remove module_disable_ro() Josh Poimboeuf
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