From: Serge Semin <fancer.lancer@gmail.com>
To: James Hogan <james.hogan@imgtec.com>
Cc: Matt Redfearn <matt.redfearn@imgtec.com>,
ralf@linux-mips.org, paul.burton@imgtec.com, rabinv@axis.com,
alexander.sverdlin@nokia.com, robh+dt@kernel.org,
frowand.list@gmail.com, Sergey.Semin@t-platforms.ru,
linux-mips@linux-mips.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 19/21] MIPS memblock: Add print out method of kernel virtual memory layout
Date: Mon, 19 Dec 2016 16:15:39 +0300 [thread overview]
Message-ID: <20161219131539.GA2101@mobilestation> (raw)
In-Reply-To: <20161219130236.GJ27950@jhogan-linux.le.imgtec.org>
On Mon, Dec 19, 2016 at 01:02:37PM +0000, James Hogan <james.hogan@imgtec.com> wrote:
> Hi Matt,
>
> On Mon, Dec 19, 2016 at 12:04:54PM +0000, Matt Redfearn wrote:
> > On 19/12/16 02:07, Serge Semin wrote:
> > > It's useful to have some printed map of the kernel virtual memory,
> > > at least for debugging purpose.
> > >
> > > Signed-off-by: Serge Semin <fancer.lancer@gmail.com>
> > > ---
>
> > > @@ -106,6 +107,49 @@ static void __init zone_sizes_init(void)
> > > }
> > >
> > > /*
> > > + * Print out kernel memory layout
> > > + */
> > > +#define MLK(b, t) b, t, ((t) - (b)) >> 10
> > > +#define MLM(b, t) b, t, ((t) - (b)) >> 20
> > > +#define MLK_ROUNDUP(b, t) b, t, DIV_ROUND_UP(((t) - (b)), SZ_1K)
> > > +static void __init mem_print_kmap_info(void)
> > > +{
> > > + pr_notice("Virtual kernel memory layout:\n"
> > > + " lowmem : 0x%08lx - 0x%08lx (%4ld MB)\n"
> > > + " vmalloc : 0x%08lx - 0x%08lx (%4ld MB)\n"
> > > +#ifdef CONFIG_HIGHMEM
> > > + " pkmap : 0x%08lx - 0x%08lx (%4ld MB)\n"
> > > +#endif
> > > + " fixmap : 0x%08lx - 0x%08lx (%4ld kB)\n"
> > > + " .text : 0x%p" " - 0x%p" " (%4td kB)\n"
> > > + " .data : 0x%p" " - 0x%p" " (%4td kB)\n"
> > > + " .init : 0x%p" " - 0x%p" " (%4td kB)\n",
> > > + MLM(PAGE_OFFSET, (unsigned long)high_memory),
> > > + MLM(VMALLOC_START, VMALLOC_END),
> > > +#ifdef CONFIG_HIGHMEM
> > > + MLM(PKMAP_BASE, (PKMAP_BASE) + (LAST_PKMAP)*(PAGE_SIZE)),
> > > +#endif
> > > + MLK(FIXADDR_START, FIXADDR_TOP),
> > > + MLK_ROUNDUP(_text, _etext),
> > > + MLK_ROUNDUP(_sdata, _edata),
> > > + MLK_ROUNDUP(__init_begin, __init_end));
> >
> > Please drop printing the kernel addresses, or at least only do it if
> > KASLR is not turned on, otherwise you're removing the advantage of
> > KASLR, that critical kernel addresses cannot be determined easily from
> > userspace.
>
> According to Documentation/printk-formats.txt, this is what %pK is for.
> Better to use that instead?
>
> Cheers
> James
>
The function is called from the kernel directly, which is privileged
enough to do the printing. So I suppose Matt is right, to hide this
prints out unless debug is enabled.
Thanks,
-Sergey
> >
> > It may be better to merge the functionality of show_kernel_relocation
> > http://lxr.free-electrons.com/source/arch/mips/kernel/relocate.c#L354
> > into this function, but only print it under the same conditions as
> > currently, i.e.
> > #if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO)
> > http://lxr.free-electrons.com/source/arch/mips/kernel/setup.c#L530
> >
> > Thanks,
> > Matt
next prev parent reply other threads:[~2016-12-19 13:15 UTC|newest]
Thread overview: 60+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-12-19 2:07 [PATCH 00/21] MIPS memblock: Remove bootmem code and switch to NO_BOOTMEM Serge Semin
2016-12-19 2:07 ` [PATCH 01/21] MIPS memblock: Unpin dts memblock sanity check method Serge Semin
2016-12-19 4:21 ` kbuild test robot
2016-12-19 4:21 ` kbuild test robot
2016-12-19 4:28 ` kbuild test robot
2016-12-19 4:28 ` kbuild test robot
2016-12-22 20:57 ` Rob Herring
2016-12-22 21:57 ` Serge Semin
2016-12-19 2:07 ` [PATCH 02/21] MIPS memblock: Add dts mem and reserved-mem callbacks Serge Semin
2016-12-19 4:13 ` kbuild test robot
2016-12-19 4:13 ` kbuild test robot
2016-12-19 2:07 ` [PATCH 03/21] MIPS memblock: Alter traditional add_memory_region() method Serge Semin
2016-12-19 2:07 ` [PATCH 04/21] MIPS memblock: Alter user-defined memory parameter parser Serge Semin
2017-01-23 7:55 ` Marcin Nowakowski
2017-01-23 7:55 ` Marcin Nowakowski
2016-12-19 2:07 ` [PATCH 05/21] MIPS memblock: Alter initrd memory reservation method Serge Semin
2016-12-19 5:08 ` kbuild test robot
2016-12-19 5:08 ` kbuild test robot
2016-12-19 2:07 ` [PATCH 06/21] MIPS memblock: Alter kexec-crashkernel parameters parser Serge Semin
2016-12-19 2:07 ` [PATCH 07/21] MIPS memblock: Alter elfcorehdr " Serge Semin
2016-12-19 4:09 ` kbuild test robot
2016-12-19 4:09 ` kbuild test robot
2016-12-19 2:07 ` [PATCH 08/21] MIPS memblock: Move kernel parameters parser into individual method Serge Semin
2016-12-19 2:07 ` [PATCH 09/21] MIPS memblock: Move kernel memory reservation to " Serge Semin
2016-12-19 2:07 ` [PATCH 10/21] MIPS memblock: Discard bootmem allocator initialization Serge Semin
2016-12-19 4:28 ` kbuild test robot
2016-12-19 4:28 ` kbuild test robot
2017-01-23 7:55 ` Marcin Nowakowski
2017-01-23 7:55 ` Marcin Nowakowski
2016-12-19 2:07 ` [PATCH 11/21] MIPS memblock: Add memblock sanity check method Serge Semin
2016-12-19 2:07 ` [PATCH 12/21] MIPS memblock: Add memblock print outs in debug Serge Semin
2016-12-19 2:07 ` [PATCH 13/21] MIPS memblock: Add memblock allocator initialization Serge Semin
2016-12-19 2:07 ` [PATCH 14/21] MIPS memblock: Alter IO resources initialization method Serge Semin
2016-12-19 2:07 ` [PATCH 15/21] MIPS memblock: Alter weakened MAAR " Serge Semin
2016-12-19 2:07 ` [PATCH 16/21] MIPS memblock: Alter paging " Serge Semin
2016-12-19 2:07 ` [PATCH 17/21] MIPS memblock: Alter high memory freeing method Serge Semin
2016-12-19 2:07 ` [PATCH 18/21] MIPS memblock: Slightly improve buddy allocator init method Serge Semin
2016-12-19 2:07 ` [PATCH 19/21] MIPS memblock: Add print out method of kernel virtual memory layout Serge Semin
2016-12-19 12:04 ` Matt Redfearn
2016-12-19 12:04 ` Matt Redfearn
2016-12-19 12:09 ` Serge Semin
2016-12-19 13:02 ` James Hogan
2016-12-19 13:02 ` James Hogan
2016-12-19 13:15 ` Serge Semin [this message]
2016-12-19 2:07 ` [PATCH 20/21] MIPS memblock: Add free low memory test method call Serge Semin
2016-12-19 2:07 ` [PATCH 21/21] MIPS memblock: Deactivate old bootmem allocator Serge Semin
2017-01-23 7:55 ` [PATCH 00/21] MIPS memblock: Remove bootmem code and switch to NO_BOOTMEM Marcin Nowakowski
2017-01-23 7:55 ` Marcin Nowakowski
2017-03-02 3:06 ` Florian Fainelli
2017-01-23 14:51 ` Joshua Kinard
2017-05-22 9:48 ` Marcin Nowakowski
2017-05-22 9:48 ` Marcin Nowakowski
2017-05-22 10:26 ` Serge Semin
2017-05-22 12:19 ` Marcin Nowakowski
2017-05-22 12:19 ` Marcin Nowakowski
2017-05-22 12:47 ` Joshua Kinard
2017-05-22 13:03 ` Serge Semin
2017-05-22 13:20 ` Alexander Sverdlin
2017-05-22 13:20 ` Alexander Sverdlin
2017-05-22 13:29 ` Serge Semin
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