From mboxrd@z Thu Jan 1 00:00:00 1970 From: Martin Pohlack Subject: Re: [RFC PATCH v3.1 2/2] xsplice: Add hook for build_id Date: Wed, 5 Aug 2015 10:50:18 +0200 Message-ID: <55C1CE4A.8000005@amazon.com> References: <1438024817-26942-1-git-send-email-konrad.wilk@oracle.com> <1438024817-26942-3-git-send-email-konrad.wilk@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xen.org with esmtp (Exim 4.72) (envelope-from ) id 1ZMuPX-0004DJ-42 for xen-devel@lists.xenproject.org; Wed, 05 Aug 2015 08:50:55 +0000 In-Reply-To: <1438024817-26942-3-git-send-email-konrad.wilk@oracle.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: Konrad Rzeszutek Wilk , xen-devel@lists.xenproject.org, msw@amazon.com, aliguori@amazon.com, amesserl@rackspace.com, rick.harris@rackspace.com, paul.voccio@rackspace.com, steven.wilson@rackspace.com, major.hayden@rackspace.com, josh.kearney@rackspace.com, jinsong.liu@alibaba-inc.com, xiantao.zxt@alibaba-inc.com, daniel.kiper@oracle.com, elena.ufimtseva@oracle.com, bob.liu@oracle.com, hanweidong@huawei.com, peter.huangpeng@huawei.com, fanhenglong@huawei.com, liuyingdong@huawei.com, john.liuqiming@huawei.com, jbeulich@suse.com, Andrew.Cooper3@citrix.com, jeremy@goop.org, dslutz@verizon.com List-Id: xen-devel@lists.xenproject.org On 27.07.2015 21:20, Konrad Rzeszutek Wilk wrote: > Signed-off-by: Konrad Rzeszutek Wilk > --- > tools/libxc/xc_private.c | 3 +++ > tools/misc/xen-xsplice.c | 25 +++++++++++++++++++++++++ > xen/common/kernel.c | 11 +++++++++++ > xen/common/version.c | 5 +++++ > xen/include/public/version.h | 4 ++++ > xen/include/xen/compile.h.in | 1 + > xen/include/xen/version.h | 1 + > 7 files changed, 50 insertions(+) > > diff --git a/tools/libxc/xc_private.c b/tools/libxc/xc_private.c > index 2ffebd9..7c039ca 100644 > --- a/tools/libxc/xc_private.c > +++ b/tools/libxc/xc_private.c > @@ -713,6 +713,9 @@ int xc_version(xc_interface *xch, int cmd, void *arg) > case XENVER_commandline: > sz = sizeof(xen_commandline_t); > break; > + case XENVER_build_id: > + sz = sizeof(xen_build_id_t); > + break; > default: > ERROR("xc_version: unknown command %d\n", cmd); > return -EINVAL; > diff --git a/tools/misc/xen-xsplice.c b/tools/misc/xen-xsplice.c > index 7cf9879..dd8266c 100644 > --- a/tools/misc/xen-xsplice.c > +++ b/tools/misc/xen-xsplice.c > @@ -17,6 +17,7 @@ void show_help(void) > " An unique name of payload. Up to 40 characters.\n" > "Commands:\n" > " help display this help\n" > + " build-id display build-id of hypervisor.\n" > " upload upload file with name\n" > " list list payloads uploaded.\n" > " apply apply patch.\n" > @@ -306,12 +307,36 @@ int action_func(int argc, char *argv[], unsigned int idx) > > return rc; > } > + > +static int build_id_func(int argc, char *argv[]) > +{ > + xen_build_id_t build_id; > + > + if ( argc ) > + { > + show_help(); > + return -1; > + } > + > + memset(build_id, 0, sizeof(*build_id)); > + > + if ( xc_version(xch, XENVER_build_id, &build_id) < 0 ) > + { > + printf("Failed to get build_id: %d(%s)\n", errno, strerror(errno)); > + return -1; > + } > + > + printf("%s\n", build_id); > + return 0; > +} > + > struct { > const char *name; > int (*function)(int argc, char *argv[]); > } main_options[] = { > { "help", help_func }, > { "list", list_func }, > + { "build-id", build_id_func }, > { "upload", upload_func }, > }; > > diff --git a/xen/common/kernel.c b/xen/common/kernel.c > index 6a3196a..e9d41b6 100644 > --- a/xen/common/kernel.c > +++ b/xen/common/kernel.c > @@ -357,6 +357,17 @@ DO(xen_version)(int cmd, XEN_GUEST_HANDLE_PARAM(void) arg) > if ( copy_to_guest(arg, saved_cmdline, ARRAY_SIZE(saved_cmdline)) ) > return -EFAULT; > return 0; > + > + case XENVER_build_id: > + { > + xen_build_id_t build_id; > + > + memset(build_id, 0, sizeof(build_id)); > + safe_strcpy(build_id, xen_build_id()); You seem to want to store and transfer the build_id as a string. Any reason why we don't directly expose the build_id embedded by the linker in binary format? > + if ( copy_to_guest(arg, build_id, ARRAY_SIZE(build_id)) ) > + return -EFAULT; > + return 0; > + } We should not expose the build_id to normal guests, but only to Dom0. A build_id uniquely identifies a specific build and I don't see how that information would be required from DomU. It might actually help an attacker to build his return-oriented programming exploit against a specific build. The normal version numbers should be enough to know about capabilities and API. > } > > return -ENOSYS; > diff --git a/xen/common/version.c b/xen/common/version.c > index b152e27..5c3dbb0 100644 > --- a/xen/common/version.c > +++ b/xen/common/version.c > @@ -55,3 +55,8 @@ const char *xen_banner(void) > { > return XEN_BANNER; > } > + > +const char *xen_build_id(void) > +{ > + return XEN_BUILD_ID; > +} > diff --git a/xen/include/public/version.h b/xen/include/public/version.h > index 44f26b0..c863393 100644 > --- a/xen/include/public/version.h > +++ b/xen/include/public/version.h > @@ -83,6 +83,10 @@ typedef struct xen_feature_info xen_feature_info_t; > #define XENVER_commandline 9 > typedef char xen_commandline_t[1024]; > > +#define XENVER_build_id 10 > +typedef char xen_build_id_t[1024]; > +#define XEN_BUILD_ID_LEN (sizeof(xen_build_id_t)) > + > #endif /* __XEN_PUBLIC_VERSION_H__ */ > > /* > diff --git a/xen/include/xen/compile.h.in b/xen/include/xen/compile.h.in > index 440ecb2..939685e 100644 > --- a/xen/include/xen/compile.h.in > +++ b/xen/include/xen/compile.h.in > @@ -10,4 +10,5 @@ > #define XEN_EXTRAVERSION "@@extraversion@@" > > #define XEN_CHANGESET "@@changeset@@" > +#define XEN_BUILD_ID "@@changeset@@" That leads to a chicken and egg problem when embedding a real build_id. Some linker script magic seems to be required. I will try to refine the patch. > #define XEN_BANNER \ > diff --git a/xen/include/xen/version.h b/xen/include/xen/version.h > index 81a3c7d..02f9585 100644 > --- a/xen/include/xen/version.h > +++ b/xen/include/xen/version.h > @@ -12,5 +12,6 @@ unsigned int xen_minor_version(void); > const char *xen_extra_version(void); > const char *xen_changeset(void); > const char *xen_banner(void); > +const char *xen_build_id(void); > > #endif /* __XEN_VERSION_H__ */ > Amazon Development Center Germany GmbH Krausenstr. 38 10117 Berlin Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger Ust-ID: DE289237879 Eingetragen am Amtsgericht Charlottenburg HRB 149173 B