From mboxrd@z Thu Jan 1 00:00:00 1970 From: Juergen Gross Subject: [Patch V3 09/15] xen: check for kernel memory conflicting with memory layout Date: Mon, 20 Apr 2015 07:23:34 +0200 Message-ID: <1429507420-18201-10-git-send-email-jgross@suse.com> References: <1429507420-18201-1-git-send-email-jgross@suse.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1429507420-18201-1-git-send-email-jgross@suse.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: linux-kernel@vger.kernel.org, xen-devel@lists.xensource.com, konrad.wilk@oracle.com, david.vrabel@citrix.com, boris.ostrovsky@oracle.comlinux-mm, @kvack.org Cc: Juergen Gross List-Id: linux-mm.kvack.org Checks whether the pre-allocated memory of the loaded kernel is in conflict with the target memory map. If this is the case, just panic instead of run into problems later, as there is nothing we can do to repair this situation. Signed-off-by: Juergen Gross Reviewed-by: David Vrabel --- arch/x86/xen/setup.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 973d294..9bd3f35 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -27,6 +27,7 @@ #include #include #include +#include #include "xen-ops.h" #include "vdso.h" #include "p2m.h" @@ -790,6 +791,17 @@ char * __init xen_memory_setup(void) sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); + /* + * Check whether the kernel itself conflicts with the target E820 map. + * Failing now is better than running into weird problems later due + * to relocating (and even reusing) pages with kernel text or data. + */ + if (xen_is_e820_reserved(__pa_symbol(_text), + __pa_symbol(__bss_stop) - __pa_symbol(_text))) { + xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); + BUG(); + } + xen_reserve_xen_mfnlist(); /* -- 2.1.4