From: Heiko Carstens <heiko.carstens@de.ibm.com>
To: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
linux-s390@vger.kernel.org,
linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
"x86@kernel.org" <x86@kernel.org>,
Kees Cook <keescook@chromium.org>,
Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@kernel.org>, "hpa@zytor.com" <hpa@zytor.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
mpe@ellerman.id.au, Michal Marek <mmarek@suse.cz>,
Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [PATCH 3/4] s390: enable text relative kallsyms for 64-bit targets
Date: Wed, 20 Jan 2016 11:17:51 +0100 [thread overview]
Message-ID: <20160120101751.GG3395@osiris> (raw)
In-Reply-To: <CAKv+Gu_nvdBqp50MZ+wHGn-nP3P3HBo_XeabqCCebEUBeVtUFQ@mail.gmail.com>
On Wed, Jan 20, 2016 at 11:04:24AM +0100, Ard Biesheuvel wrote:
> On 20 January 2016 at 10:43, Heiko Carstens <heiko.carstens@de.ibm.com> wrote:
> > On Wed, Jan 20, 2016 at 10:05:37AM +0100, Ard Biesheuvel wrote:
> >> This enables the newly introduced text-relative kallsyms support when
> >> building 64-bit targets. This cuts the size of the kallsyms address
> >> table in half, reducing the memory footprint of the kernel .rodata
> >> section by about 250 KB for a defconfig build.
> >>
> >> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
> >> ---
> >>
> >> diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
> >> index dbeeb3a049f2..588160fd1db0 100644
> >> --- a/arch/s390/Kconfig
> >> +++ b/arch/s390/Kconfig
> >> @@ -149,6 +149,7 @@ config S390
> >> select HAVE_REGS_AND_STACK_ACCESS_API
> >> select HAVE_SYSCALL_TRACEPOINTS
> >> select HAVE_VIRT_CPU_ACCOUNTING
> >> + select KALLSYMS_TEXT_RELATIVE if 64BIT
> >
> > Please remove the "if 64BIT" since s390 is always 64BIT in the meantime.
> > Tested on s390 and everything seems still to work ;)
> >
> > Acked-by: Heiko Carstens <heiko.carstens@de.ibm.com>
> >
>
> Thanks! Did you take a look at /proc/kallsyms, by any chance? It
> should look identical with and without these patches
Close to identical, since the generated code and offsets change a bit with
your new config option enabled and disabled. But only those parts that are
linked behind kernel/kallsyms.c.
However I did run a couple of ftrace, kprobes tests and enforced call
backtraces. Everything still works.
So it looks all good.
next prev parent reply other threads:[~2016-01-20 10:17 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-20 9:05 [PATCH 0/4] support for text-relative kallsyms table Ard Biesheuvel
2016-01-20 9:05 ` [PATCH 1/4] kallsyms: add support for relative offsets in kallsyms address table Ard Biesheuvel
2016-01-20 19:13 ` Kees Cook
2016-01-20 9:05 ` [PATCH 2/4] powerpc: enable text relative kallsyms for ppc64 Ard Biesheuvel
2016-01-21 4:01 ` Michael Ellerman
2016-01-20 9:05 ` [PATCH 3/4] s390: enable text relative kallsyms for 64-bit targets Ard Biesheuvel
2016-01-20 9:43 ` Heiko Carstens
2016-01-20 10:04 ` Ard Biesheuvel
2016-01-20 10:17 ` Heiko Carstens [this message]
2016-01-20 10:18 ` Ard Biesheuvel
2016-01-20 9:05 ` [PATCH 4/4] x86_64: " Ard Biesheuvel
2016-01-20 19:12 ` Kees Cook
2016-01-20 10:33 ` [PATCH 0/4] support for text-relative kallsyms table Ingo Molnar
2016-01-20 11:50 ` Arnd Bergmann
2016-01-21 5:10 ` Rusty Russell
2016-01-21 6:45 ` Ard Biesheuvel
2016-01-21 8:32 ` Ard Biesheuvel
2016-01-27 3:46 ` Rusty Russell
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