Re: [PATCH v2] x86_64, vmcoreinfo: Append 'page_offset_base' to vmcoreinfo

From: Bhupesh Sharma <bhsharma@redhat.com>
To: Baoquan He <bhe@redhat.com>
Cc: Kees Cook <keescook@chromium.org>, Borislav Petkov <bp@alien8.de>,
	Kazuhito Hagio <k-hagio@ab.jp.nec.com>,
	x86@kernel.org, kexec mailing list <kexec@lists.infradead.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
	Omar Sandoval <osandov@fb.com>,
	Dave Anderson <anderson@redhat.com>,
	James Morse <james.morse@arm.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Bhupesh SHARMA <bhupesh.linux@gmail.com>,
	Ingo Molnar <mingo@kernel.org>,
	linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v2] x86_64, vmcoreinfo: Append 'page_offset_base' to vmcoreinfo
Date: Wed, 28 Nov 2018 09:56:24 +0530	[thread overview]
Message-ID: <CACi5LpM23rZQVe-bDirfNEODwe-zZDo0VyTFUG_969mgisL+gA@mail.gmail.com> (raw)
In-Reply-To: <20181128015754.GI1824@MiWiFi-R3L-srv>

On Wed, Nov 28, 2018 at 7:27 AM Baoquan He <bhe@redhat.com> wrote:
>
> On 11/27/18 at 04:39pm, Kees Cook wrote:
> > >> >> diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_kexec_64.c
> > >> >> index 4c8acdfdc5a7..6161d77c5bfb 100644
> > >> >> --- a/arch/x86/kernel/machine_kexec_64.c
> > >> >> +++ b/arch/x86/kernel/machine_kexec_64.c
> > >> >> @@ -356,6 +356,9 @@ void arch_crash_save_vmcoreinfo(void)
> > >> >>       VMCOREINFO_SYMBOL(init_top_pgt);
> > >> >>       vmcoreinfo_append_str("NUMBER(pgtable_l5_enabled)=%d\n",
> > >> >>                       pgtable_l5_enabled());
> > >> >> +#ifdef CONFIG_RANDOMIZE_BASE
> >
> > Okay, gotcha. In that case, shouldn't this be CONFIG_RANDOMIZE_MEMORY?
>
> And yes, if we only care about KASLR, it should be
> CONFIG_RANDOMIZE_MEMORY, but not CONFIG_RANDOMIZE_BASE.
>

Have you tried building the changes with 'make allmodconfig' with all
the different CONFIG options you have suggested so far?