From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TiKvQ-0005cS-79 for kexec@lists.infradead.org; Tue, 11 Dec 2012 08:10:49 +0000 Date: Tue, 11 Dec 2012 10:10:24 +0200 From: Gleb Natapov Subject: Re: [PATCH] x86/kexec: crash_vmclear_local_vmcss needs __rcu Message-ID: <20121211081024.GC11016@redhat.com> References: <50C18168.305@cn.fujitsu.com> <20121210203014.GB2402@amt.cnet> <50C6E927.9040605@cn.fujitsu.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <50C6E927.9040605@cn.fujitsu.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: kexec-bounces@lists.infradead.org Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Zhang Yanfei Cc: "kvm@vger.kernel.org" , Marcelo Tosatti , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "Eric W. Biederman" , kbuild test robot T24gVHVlLCBEZWMgMTEsIDIwMTIgYXQgMDQ6MDQ6NTVQTSArMDgwMCwgWmhhbmcgWWFuZmVpIHdy b3RlOgo+IOS6jiAyMDEy5bm0MTLmnIgxMeaXpSAwNDozMCwgTWFyY2VsbyBUb3NhdHRpIOWGmemB kzoKPiA+IE9uIEZyaSwgRGVjIDA3LCAyMDEyIGF0IDAxOjQwOjU2UE0gKzA4MDAsIFpoYW5nIFlh bmZlaSB3cm90ZToKPiA+PiBUaGlzIHJlbW92ZXMgdGhlIHNwYXJzZSB3YXJuaW5nOgo+ID4+IGFy Y2gveDg2L2tlcm5lbC9jcmFzaC5jOjQ5OjMyOiBzcGFyc2U6IGluY29tcGF0aWJsZSB0eXBlcyBp biBjb21wYXJpc29uIGV4cHJlc3Npb24gKGRpZmZlcmVudCBhZGRyZXNzIHNwYWNlcykKPiA+Pgo+ ID4+IFJlcG9ydGVkLWJ5OiBrYnVpbGQgdGVzdCByb2JvdCA8ZmVuZ2d1YW5nLnd1QGludGVsLmNv bT4KPiA+PiBTaWduZWQtb2ZmLWJ5OiBaaGFuZyBZYW5mZWkgPHpoYW5neWFuZmVpQGNuLmZ1aml0 c3UuY29tPgo+ID4+IC0tLQo+ID4+ICBhcmNoL3g4Ni9pbmNsdWRlL2FzbS9rZXhlYy5oIHwgICAg NCArKystCj4gPj4gIGFyY2gveDg2L2tlcm5lbC9jcmFzaC5jICAgICAgfCAgICA0ICsrLS0KPiA+ PiAgMiBmaWxlcyBjaGFuZ2VkLCA1IGluc2VydGlvbnMoKyksIDMgZGVsZXRpb25zKC0pCj4gPj4K PiA+PiBkaWZmIC0tZ2l0IGEvYXJjaC94ODYvaW5jbHVkZS9hc20va2V4ZWMuaCBiL2FyY2gveDg2 L2luY2x1ZGUvYXNtL2tleGVjLmgKPiA+PiBpbmRleCAyOGZlZWJhLi4xNjg4MmNkIDEwMDY0NAo+ ID4+IC0tLSBhL2FyY2gveDg2L2luY2x1ZGUvYXNtL2tleGVjLmgKPiA+PiArKysgYi9hcmNoL3g4 Ni9pbmNsdWRlL2FzbS9rZXhlYy5oCj4gPj4gQEAgLTE2Myw3ICsxNjMsOSBAQCBzdHJ1Y3Qga2lt YWdlX2FyY2ggewo+ID4+ICB9Owo+ID4+ICAjZW5kaWYKPiA+PiAgCj4gPj4gLWV4dGVybiB2b2lk ICgqY3Jhc2hfdm1jbGVhcl9sb2FkZWRfdm1jc3MpKHZvaWQpOwo+ID4+ICtleHRlcm4gdm9pZCBf X3JjdSAoKmNyYXNoX3ZtY2xlYXJfbG9hZGVkX3ZtY3NzKSh2b2lkKTsKPiA+PiArI2RlZmluZSB2 bWNsZWFyX2Z1bmNfcmN1KHZtY2xlYXJfZnVuYykgXAo+ID4+ICsJKCh2b2lkICgqKSh2b2lkKSkg cmN1X2RlcmVmZXJlbmNlKHZtY2xlYXJfZnVuYykpCj4gPj4gIAo+ID4+ICAjZW5kaWYgLyogX19B U1NFTUJMWV9fICovCj4gPj4gIAo+ID4+IGRpZmYgLS1naXQgYS9hcmNoL3g4Ni9rZXJuZWwvY3Jh c2guYyBiL2FyY2gveDg2L2tlcm5lbC9jcmFzaC5jCj4gPj4gaW5kZXggMmY2YjhlOC4uNTBjZTFk NiAxMDA2NDQKPiA+PiAtLS0gYS9hcmNoL3g4Ni9rZXJuZWwvY3Jhc2guYwo+ID4+ICsrKyBiL2Fy Y2gveDg2L2tlcm5lbC9jcmFzaC5jCj4gPj4gQEAgLTM4LDcgKzM4LDcgQEAgaW50IGluX2NyYXNo X2tleGVjOwo+ID4+ICAgKgo+ID4+ICAgKiBwcm90ZWN0ZWQgYnkgcmN1Lgo+ID4+ICAgKi8KPiA+ PiAtdm9pZCAoKmNyYXNoX3ZtY2xlYXJfbG9hZGVkX3ZtY3NzKSh2b2lkKSA9IE5VTEw7Cj4gPj4g K3ZvaWQgX19yY3UgKCpjcmFzaF92bWNsZWFyX2xvYWRlZF92bWNzcykodm9pZCkgPSBOVUxMOwo+ ID4gCj4gPiBJc250IHRoaXMgKF9fcmN1IEFTIHRhZykgc3VmZmljaWVudD8gQWZ0ZXIgYWxsLCBz cGFyc2UgaXMgY29tcGxhaW5pbmcKPiA+IGFib3V0IG5hbWVzcGFjZXMuCj4gPiAKPiA+IENyZWF0 aW5nIGEgI2RlZmluZSB0byBjYXN0IHNlZW1zIGV4Y2Vzc2l2ZS4KPiA+IAo+ID4gCj4gCj4gSSBh bSBub3QgdmVyeSBmYW1pbGlhciB3aXRoIHRoZSByY3UuCj4gQWRkaW5nIF9fcmN1IHRhZyBjb3Vs ZCBzb2x2ZSB0aGUgcHJvYmxlbS4gQnV0IGl0IGltcG9ydGVkIGFub3RoZXIgd2FybmluZwo+IHdo ZW4gSSB0cnkgdG8gYXNzaWduIHJjdV9kZXJlZmVyZW5jZShjcmFzaF92bWNsZWFyX2xvYWRlZF92 bWNzcykgdG8KPiBkb192bWNsZWFyX29wZXJhdGlvbjoKPiAKPiBhcmNoL3g4Ni9rZXJuZWwvY3Jh c2guYzo0OTozMDogd2FybmluZzogaW5jb3JyZWN0IHR5cGUgaW4gYXNzaWdubWVudCAoZGlmZmVy ZW50IG1vZGlmaWVycykKPiBhcmNoL3g4Ni9rZXJuZWwvY3Jhc2guYzo0OTozMDogICAgZXhwZWN0 ZWQgdm9pZCAoICpkb192bWNsZWFyX29wZXJhdGlvbiApKCAuLi4gKQo+IGFyY2gveDg2L2tlcm5l bC9jcmFzaC5jOjQ5OjMwOiAgICBnb3Qgdm9pZCAoIFtub2RlcmVmXSAqPG5vaWRlbnQ+ICkoIC4u LiApCj4gYXJjaC94ODYva2VybmVsL2NyYXNoLmM6NDk6MzA6IHdhcm5pbmc6IGluY29ycmVjdCB0 eXBlIGluIGFzc2lnbm1lbnQgKGRpZmZlcmVudCBtb2RpZmllcnMpCj4gYXJjaC94ODYva2VybmVs L2NyYXNoLmM6NDk6MzA6ICAgIGV4cGVjdGVkIHZvaWQgKCAqZG9fdm1jbGVhcl9vcGVyYXRpb24g KSggLi4uICkKPiBhcmNoL3g4Ni9rZXJuZWwvY3Jhc2guYzo0OTozMDogICAgZ290IHZvaWQgKCBb bm9kZXJlZl0gKjxub2lkZW50PiApKCAuLi4gKQo+IAo+IFNvIEkgbWFkZSB0aGUgI2RlZmluZSB0 byBjYXN0IGl0cyB0eXBlLgo+IAo+IElmIHlvdSBoYXZlIGFueSBzdWdnZXN0aW9uLCB0aGF0J2xs IGJlIGhlbHBmdWwuCj4gClRyeSB0byB1c2UgdHlwZWRlZi4KCi0tCgkJCUdsZWIuCgpfX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwprZXhlYyBtYWlsaW5nIGxp c3QKa2V4ZWNAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9t YWlsbWFuL2xpc3RpbmZvL2tleGVjCg== From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCH] x86/kexec: crash_vmclear_local_vmcss needs __rcu Date: Tue, 11 Dec 2012 10:10:24 +0200 Message-ID: <20121211081024.GC11016@redhat.com> References: <50C18168.305@cn.fujitsu.com> <20121210203014.GB2402@amt.cnet> <50C6E927.9040605@cn.fujitsu.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Cc: "kvm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Marcelo Tosatti , "kexec-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "Eric W. Biederman" , kbuild test robot To: Zhang Yanfei Return-path: Content-Disposition: inline In-Reply-To: <50C6E927.9040605-BthXqXjhjHXQFUHtdCDX3A@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kexec-bounces-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org Errors-To: kexec-bounces+glkk-kexec=m.gmane.org-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: kvm.vger.kernel.org T24gVHVlLCBEZWMgMTEsIDIwMTIgYXQgMDQ6MDQ6NTVQTSArMDgwMCwgWmhhbmcgWWFuZmVpIHdy b3RlOgo+IOS6jiAyMDEy5bm0MTLmnIgxMeaXpSAwNDozMCwgTWFyY2VsbyBUb3NhdHRpIOWGmemB kzoKPiA+IE9uIEZyaSwgRGVjIDA3LCAyMDEyIGF0IDAxOjQwOjU2UE0gKzA4MDAsIFpoYW5nIFlh bmZlaSB3cm90ZToKPiA+PiBUaGlzIHJlbW92ZXMgdGhlIHNwYXJzZSB3YXJuaW5nOgo+ID4+IGFy Y2gveDg2L2tlcm5lbC9jcmFzaC5jOjQ5OjMyOiBzcGFyc2U6IGluY29tcGF0aWJsZSB0eXBlcyBp biBjb21wYXJpc29uIGV4cHJlc3Npb24gKGRpZmZlcmVudCBhZGRyZXNzIHNwYWNlcykKPiA+Pgo+ ID4+IFJlcG9ydGVkLWJ5OiBrYnVpbGQgdGVzdCByb2JvdCA8ZmVuZ2d1YW5nLnd1QGludGVsLmNv bT4KPiA+PiBTaWduZWQtb2ZmLWJ5OiBaaGFuZyBZYW5mZWkgPHpoYW5neWFuZmVpQGNuLmZ1aml0 c3UuY29tPgo+ID4+IC0tLQo+ID4+ICBhcmNoL3g4Ni9pbmNsdWRlL2FzbS9rZXhlYy5oIHwgICAg NCArKystCj4gPj4gIGFyY2gveDg2L2tlcm5lbC9jcmFzaC5jICAgICAgfCAgICA0ICsrLS0KPiA+ PiAgMiBmaWxlcyBjaGFuZ2VkLCA1IGluc2VydGlvbnMoKyksIDMgZGVsZXRpb25zKC0pCj4gPj4K PiA+PiBkaWZmIC0tZ2l0IGEvYXJjaC94ODYvaW5jbHVkZS9hc20va2V4ZWMuaCBiL2FyY2gveDg2 L2luY2x1ZGUvYXNtL2tleGVjLmgKPiA+PiBpbmRleCAyOGZlZWJhLi4xNjg4MmNkIDEwMDY0NAo+ ID4+IC0tLSBhL2FyY2gveDg2L2luY2x1ZGUvYXNtL2tleGVjLmgKPiA+PiArKysgYi9hcmNoL3g4 Ni9pbmNsdWRlL2FzbS9rZXhlYy5oCj4gPj4gQEAgLTE2Myw3ICsxNjMsOSBAQCBzdHJ1Y3Qga2lt YWdlX2FyY2ggewo+ID4+ICB9Owo+ID4+ICAjZW5kaWYKPiA+PiAgCj4gPj4gLWV4dGVybiB2b2lk ICgqY3Jhc2hfdm1jbGVhcl9sb2FkZWRfdm1jc3MpKHZvaWQpOwo+ID4+ICtleHRlcm4gdm9pZCBf X3JjdSAoKmNyYXNoX3ZtY2xlYXJfbG9hZGVkX3ZtY3NzKSh2b2lkKTsKPiA+PiArI2RlZmluZSB2 bWNsZWFyX2Z1bmNfcmN1KHZtY2xlYXJfZnVuYykgXAo+ID4+ICsJKCh2b2lkICgqKSh2b2lkKSkg cmN1X2RlcmVmZXJlbmNlKHZtY2xlYXJfZnVuYykpCj4gPj4gIAo+ID4+ICAjZW5kaWYgLyogX19B U1NFTUJMWV9fICovCj4gPj4gIAo+ID4+IGRpZmYgLS1naXQgYS9hcmNoL3g4Ni9rZXJuZWwvY3Jh c2guYyBiL2FyY2gveDg2L2tlcm5lbC9jcmFzaC5jCj4gPj4gaW5kZXggMmY2YjhlOC4uNTBjZTFk NiAxMDA2NDQKPiA+PiAtLS0gYS9hcmNoL3g4Ni9rZXJuZWwvY3Jhc2guYwo+ID4+ICsrKyBiL2Fy Y2gveDg2L2tlcm5lbC9jcmFzaC5jCj4gPj4gQEAgLTM4LDcgKzM4LDcgQEAgaW50IGluX2NyYXNo X2tleGVjOwo+ID4+ICAgKgo+ID4+ICAgKiBwcm90ZWN0ZWQgYnkgcmN1Lgo+ID4+ICAgKi8KPiA+ PiAtdm9pZCAoKmNyYXNoX3ZtY2xlYXJfbG9hZGVkX3ZtY3NzKSh2b2lkKSA9IE5VTEw7Cj4gPj4g K3ZvaWQgX19yY3UgKCpjcmFzaF92bWNsZWFyX2xvYWRlZF92bWNzcykodm9pZCkgPSBOVUxMOwo+ ID4gCj4gPiBJc250IHRoaXMgKF9fcmN1IEFTIHRhZykgc3VmZmljaWVudD8gQWZ0ZXIgYWxsLCBz cGFyc2UgaXMgY29tcGxhaW5pbmcKPiA+IGFib3V0IG5hbWVzcGFjZXMuCj4gPiAKPiA+IENyZWF0 aW5nIGEgI2RlZmluZSB0byBjYXN0IHNlZW1zIGV4Y2Vzc2l2ZS4KPiA+IAo+ID4gCj4gCj4gSSBh bSBub3QgdmVyeSBmYW1pbGlhciB3aXRoIHRoZSByY3UuCj4gQWRkaW5nIF9fcmN1IHRhZyBjb3Vs ZCBzb2x2ZSB0aGUgcHJvYmxlbS4gQnV0IGl0IGltcG9ydGVkIGFub3RoZXIgd2FybmluZwo+IHdo ZW4gSSB0cnkgdG8gYXNzaWduIHJjdV9kZXJlZmVyZW5jZShjcmFzaF92bWNsZWFyX2xvYWRlZF92 bWNzcykgdG8KPiBkb192bWNsZWFyX29wZXJhdGlvbjoKPiAKPiBhcmNoL3g4Ni9rZXJuZWwvY3Jh c2guYzo0OTozMDogd2FybmluZzogaW5jb3JyZWN0IHR5cGUgaW4gYXNzaWdubWVudCAoZGlmZmVy ZW50IG1vZGlmaWVycykKPiBhcmNoL3g4Ni9rZXJuZWwvY3Jhc2guYzo0OTozMDogICAgZXhwZWN0 ZWQgdm9pZCAoICpkb192bWNsZWFyX29wZXJhdGlvbiApKCAuLi4gKQo+IGFyY2gveDg2L2tlcm5l bC9jcmFzaC5jOjQ5OjMwOiAgICBnb3Qgdm9pZCAoIFtub2RlcmVmXSAqPG5vaWRlbnQ+ICkoIC4u LiApCj4gYXJjaC94ODYva2VybmVsL2NyYXNoLmM6NDk6MzA6IHdhcm5pbmc6IGluY29ycmVjdCB0 eXBlIGluIGFzc2lnbm1lbnQgKGRpZmZlcmVudCBtb2RpZmllcnMpCj4gYXJjaC94ODYva2VybmVs L2NyYXNoLmM6NDk6MzA6ICAgIGV4cGVjdGVkIHZvaWQgKCAqZG9fdm1jbGVhcl9vcGVyYXRpb24g KSggLi4uICkKPiBhcmNoL3g4Ni9rZXJuZWwvY3Jhc2guYzo0OTozMDogICAgZ290IHZvaWQgKCBb bm9kZXJlZl0gKjxub2lkZW50PiApKCAuLi4gKQo+IAo+IFNvIEkgbWFkZSB0aGUgI2RlZmluZSB0 byBjYXN0IGl0cyB0eXBlLgo+IAo+IElmIHlvdSBoYXZlIGFueSBzdWdnZXN0aW9uLCB0aGF0J2xs IGJlIGhlbHBmdWwuCj4gClRyeSB0byB1c2UgdHlwZWRlZi4KCi0tCgkJCUdsZWIuCgpfX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fXwprZXhlYyBtYWlsaW5nIGxp c3QKa2V4ZWNAbGlzdHMuaW5mcmFkZWFkLm9yZwpodHRwOi8vbGlzdHMuaW5mcmFkZWFkLm9yZy9t YWlsbWFuL2xpc3RpbmZvL2tleGVjCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753070Ab2LKIKv (ORCPT ); Tue, 11 Dec 2012 03:10:51 -0500 Received: from mx1.redhat.com ([209.132.183.28]:24940 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751421Ab2LKIKu convert rfc822-to-8bit (ORCPT ); Tue, 11 Dec 2012 03:10:50 -0500 Date: Tue, 11 Dec 2012 10:10:24 +0200 From: Gleb Natapov To: Zhang Yanfei Cc: Marcelo Tosatti , "Eric W. Biederman" , "kvm@vger.kernel.org" , "kexec@lists.infradead.org" , "linux-kernel@vger.kernel.org" , kbuild test robot Subject: Re: [PATCH] x86/kexec: crash_vmclear_local_vmcss needs __rcu Message-ID: <20121211081024.GC11016@redhat.com> References: <50C18168.305@cn.fujitsu.com> <20121210203014.GB2402@amt.cnet> <50C6E927.9040605@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8BIT In-Reply-To: <50C6E927.9040605@cn.fujitsu.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Dec 11, 2012 at 04:04:55PM +0800, Zhang Yanfei wrote: > 于 2012年12月11日 04:30, Marcelo Tosatti 写道: > > On Fri, Dec 07, 2012 at 01:40:56PM +0800, Zhang Yanfei wrote: > >> This removes the sparse warning: > >> arch/x86/kernel/crash.c:49:32: sparse: incompatible types in comparison expression (different address spaces) > >> > >> Reported-by: kbuild test robot > >> Signed-off-by: Zhang Yanfei > >> --- > >> arch/x86/include/asm/kexec.h | 4 +++- > >> arch/x86/kernel/crash.c | 4 ++-- > >> 2 files changed, 5 insertions(+), 3 deletions(-) > >> > >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h > >> index 28feeba..16882cd 100644 > >> --- a/arch/x86/include/asm/kexec.h > >> +++ b/arch/x86/include/asm/kexec.h > >> @@ -163,7 +163,9 @@ struct kimage_arch { > >> }; > >> #endif > >> > >> -extern void (*crash_vmclear_loaded_vmcss)(void); > >> +extern void __rcu (*crash_vmclear_loaded_vmcss)(void); > >> +#define vmclear_func_rcu(vmclear_func) \ > >> + ((void (*)(void)) rcu_dereference(vmclear_func)) > >> > >> #endif /* __ASSEMBLY__ */ > >> > >> diff --git a/arch/x86/kernel/crash.c b/arch/x86/kernel/crash.c > >> index 2f6b8e8..50ce1d6 100644 > >> --- a/arch/x86/kernel/crash.c > >> +++ b/arch/x86/kernel/crash.c > >> @@ -38,7 +38,7 @@ int in_crash_kexec; > >> * > >> * protected by rcu. > >> */ > >> -void (*crash_vmclear_loaded_vmcss)(void) = NULL; > >> +void __rcu (*crash_vmclear_loaded_vmcss)(void) = NULL; > > > > Isnt this (__rcu AS tag) sufficient? After all, sparse is complaining > > about namespaces. > > > > Creating a #define to cast seems excessive. > > > > > > I am not very familiar with the rcu. > Adding __rcu tag could solve the problem. But it imported another warning > when I try to assign rcu_dereference(crash_vmclear_loaded_vmcss) to > do_vmclear_operation: > > arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) > arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) > arch/x86/kernel/crash.c:49:30: got void ( [noderef] * )( ... ) > arch/x86/kernel/crash.c:49:30: warning: incorrect type in assignment (different modifiers) > arch/x86/kernel/crash.c:49:30: expected void ( *do_vmclear_operation )( ... ) > arch/x86/kernel/crash.c:49:30: got void ( [noderef] * )( ... ) > > So I made the #define to cast its type. > > If you have any suggestion, that'll be helpful. > Try to use typedef. -- Gleb.