Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763287AbcLSMI7 (ORCPT ); Mon, 19 Dec 2016 07:08:59 -0500 Received: from mail-lf0-f66.google.com ([209.85.215.66]:36845 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751673AbcLSMI6 (ORCPT ); Mon, 19 Dec 2016 07:08:58 -0500 Date: Mon, 19 Dec 2016 15:09:00 +0300 From: Serge Semin To: Matt Redfearn Cc: ralf@linux-mips.org, paul.burton@imgtec.com, rabinv@axis.com, james.hogan@imgtec.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 Message-ID: <20161219120900.GA30965@mobilestation> References: <1482113266-13207-1-git-send-email-fancer.lancer@gmail.com> <1482113266-13207-20-git-send-email-fancer.lancer@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3603 Lines: 102 On Mon, Dec 19, 2016 at 12:04:54PM +0000, Matt Redfearn wrote: Hello Matt. > Hi Serge, > > > 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 > >--- > > arch/mips/mm/init.c | 47 +++++++++++++++++++++++++++++++++++ > > 1 file changed, 47 insertions(+) > > > >diff --git a/arch/mips/mm/init.c b/arch/mips/mm/init.c > >index 13a032f..35e7ba8 100644 > >--- a/arch/mips/mm/init.c > >+++ b/arch/mips/mm/init.c > >@@ -32,6 +32,7 @@ > > #include > > #include > > #include > >+#include > > #include > > #include > >@@ -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. > > 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 > Understood. Will be fixed within the next patchset. > >+ > >+ /* Check some fundamental inconsistencies. May add something else? */ > >+#ifdef CONFIG_HIGHMEM > >+ BUILD_BUG_ON(VMALLOC_END < PAGE_OFFSET); > >+ BUG_ON(VMALLOC_END < (unsigned long)high_memory); > >+#endif > >+ BUILD_BUG_ON((PKMAP_BASE) + (LAST_PKMAP)*(PAGE_SIZE) < PAGE_OFFSET); > >+ BUG_ON((PKMAP_BASE) + (LAST_PKMAP)*(PAGE_SIZE) < > >+ (unsigned long)high_memory); > >+ BUILD_BUG_ON(FIXADDR_TOP < PAGE_OFFSET); > >+ BUG_ON(FIXADDR_TOP < (unsigned long)high_memory); > >+} > >+#undef MLK > >+#undef MLM > >+#undef MLK_ROUNDUP > >+ > >+/* > > * Not static inline because used by IP27 special magic initialization code > > */ > > void setup_zero_pages(void) > >@@ -492,6 +536,9 @@ void __init mem_init(void) > > /* Free highmemory registered in memblocks */ > > mem_init_free_highmem(); > >+ /* Print out kernel memory layout */ > >+ mem_print_kmap_info(); > >+ > > /* Print out memory areas statistics */ > > mem_init_print_info(NULL); >