From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lWFbs-006tOj-8G for kexec@lists.infradead.org; Tue, 13 Apr 2021 09:45:29 +0000 Date: Tue, 13 Apr 2021 17:45:15 +0800 From: Baoquan He Subject: Re: [PATCH] x86/efi: Do not release sub-1MB memory regions when the crashkernel option is specified Message-ID: <20210413094515.GD4282@MiWiFi-R3L-srv> References: <20210412011347.GA4282@MiWiFi-R3L-srv> <8FAA2A0E-0A09-4308-B936-CDD2C0568BAE@amacapital.net> <20210412095231.GC4282@MiWiFi-R3L-srv> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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" Errors-To: kexec-bounces+dwmw2=infradead.org@lists.infradead.org To: Andy Lutomirski Cc: "H. Peter Anvin" , Lianbo Jiang , LKML , linux-efi , Platform Driver , X86 ML , Ard Biesheuvel , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Darren Hart , Andy Shevchenko , kexec@lists.infradead.org, Dave Young T24gMDQvMTIvMjEgYXQgMDg6MjRhbSwgQW5keSBMdXRvbWlyc2tpIHdyb3RlOgo+IE9uIE1vbiwg QXByIDEyLCAyMDIxIGF0IDI6NTIgQU0gQmFvcXVhbiBIZSA8YmhlQHJlZGhhdC5jb20+IHdyb3Rl Ogo+ID4KPiA+IE9uIDA0LzExLzIxIGF0IDA2OjQ5cG0sIEFuZHkgTHV0b21pcnNraSB3cm90ZToK PiA+ID4KPiA+ID4KPiA+ID4gPiBPbiBBcHIgMTEsIDIwMjEsIGF0IDY6MTQgUE0sIEJhb3F1YW4g SGUgPGJoZUByZWRoYXQuY29tPiB3cm90ZToKPiA+ID4gPgo+ID4gPiA+IO+7v09uIDA0LzA5LzIx IGF0IDA3OjU5cG0sIEguIFBldGVyIEFudmluIHdyb3RlOgo+ID4gPiA+PiBXaHkgZG9uJ3Qgd2Ug ZG8gdGhpcyB1bmNvbmRpdGlvbmFsbHk/IEF0IHRoZSB2ZXJ5IGJlc3Qgd2UgZ2FpbiBoYWxmIGEg bWVnYWJ5dGUgb2YgbWVtb3J5IChleGNlcHQgdGhlIHRyYW1wb2xpbmUsIHdoaWNoIGhhcyB0byBs aXZlIHRoZXJlLCBidXQgaXQgaXMgb25seSBhIGZldyBraWxvYnl0ZXMuKQo+ID4gPiA+Cj4gPiA+ ID4gVGhpcyBpcyBhIGdyZWF0IHN1Z2dlc3Rpb24sIHRoYW5rcy4gSSB0aGluayB3ZSBjYW4gZml4 IGl0IGluIHRoaXMgd2F5IHRvCj4gPiA+ID4gbWFrZSBjb2RlIHNpbXBsZXIuIFRoZW4gdGhlIHNw ZWNpZmljIGNhcmluZyBvZiByZWFsIG1vZGUgaW4KPiA+ID4gPiBlZmlfZnJlZV9ib290X3NlcnZp Y2VzKCkgY2FuIGJlIHJlbW92ZWQgdG9vLgo+ID4gPiA+Cj4gPiA+Cj4gPiA+IFRoaXMgd2hvbGUg c2l0dWF0aW9uIG1ha2VzIG1lIHRoaW5rIHRoYXQgdGhlIGNvZGUgaXMgYnVnZ3kgYmVmb3JlIGFu ZCBidWdneSBhZnRlci4KPiA+ID4KPiA+ID4gVGhlIGlzc3VlIGhlcmUgKEkgdGhpbmspIGlzIHRo YXQgdmFyaW91cyBwaWVjZXMgb2YgY29kZSB3YW50IHRvIHJlc2VydmUgc3BlY2lmaWMgcGllY2Vz IG9mIG90aGVyd2lzZS1hdmFpbGFibGUgbG93IG1lbW9yeSBmb3IgdGhlaXIgb3duIG5lZmFyaW91 cyB1c2VzLiBJIGRvbuKAmXQga25vdyAqd2h5KiBjcmFzaCBrZXJuZWwgbmVlZHMgdGhpcywgYnV0 IHRoYXQgZG9lc27igJl0IG1hdHRlciB0b28gbXVjaC4KPiA+Cj4gPiBLZHVtcCBrZXJuZWwgYWxz byBuZWVkIGdvIHRocm91Z2ggcmVhbCBtb2RlIGNvZGUgcGF0aCBkdXJpbmcgYm9vdHVwLiBJdAo+ ID4gaXMgbm90IGRpZmZlcmVudCB0aGFuIG5vcm1hbCBrZXJuZWwgZXhjZXB0IHRoYXQgaXQgc2tp cHMgdGhlIGZpcm13YXJlCj4gPiByZXNldHRpbmcuIFNvIGtkdW1wIGtlcm5lbCBuZWVkcyBsb3cg MU0gYXMgc3lzdGVtIFJBTSBqdXN0IGFzIG5vcm1hbAo+ID4ga2VybmVsIGRvZXMuIEhlcmUgd2Ug cmVzZXJ2ZSB0aGUgd2hvbGUgbG93IDFNIHdpdGggbWVtYmxvY2tfcmVzZXJ2ZSgpCj4gPiB0byBh dm9pZCBhbnkgbGF0ZXIga2VybmVsIG9yIGRyaXZlciBkYXRhIHJlc2lkZSBpbiB0aGlzIGFyZWEu IE90aGVyd2lzZSwKPiA+IHdlIG5lZWQgZHVtcCB0aGUgY29udGVudCBvZiB0aGlzIGFyZWEgdG8g dm1jb3JlLiBBcyB3ZSBrbm93LCB3aGVuIGNyYXNoCj4gPiBoYXBwZW5lZCwgdGhlIG9sZCBtZW1v cnkgb2YgMXN0IGtlcm5lbCBzaG91bGQgYmUgdW50b3VjaGVkIHVudGlsIHZtY29yZQo+ID4gZHVt cGluZyByZWFkIG91dCBpdHMgY29udGVudC4gTWVhbndoaWxlLCBrZHVtcCBrZXJuZWwgbmVlZCBy ZXVzZSBsb3cgMU0uCj4gPiBJbiB0aGUgcGFzdCwgd2UgdXNlZCBhIGJhY2sgdXAgcmVnaW9uIHRv IGNvcHkgb3V0IHRoZSBsb3cgMU0gYXJlYSwgYW5kCj4gPiBtYXAgdGhlIGJhY2sgdXAgcmVnaW9u IGludG8gdGhlIGxvdyAxTSBhcmVhIGluIHZtY29yZSBlbGYgZmlsZS4gSW4KPiA+IDZmNTk5ZDg0 MjMxZmQyNyAoIng4Ni9rZHVtcDogQWx3YXlzIHJlc2VydmUgdGhlIGxvdyAxTSB3aGVuIHRoZSBj cmFzaGtlcm5lbAo+ID4gb3B0aW9uIGlzIHNwZWNpZmllZCIpLCB3ZSBjaGFuZ2VkIHRvIGxvY2sg dGhlIHdob2xlIGxvdyAxTSB0byBhdm9pZAo+ID4gd3JpdHRpbmcgYW55IGtlcm5lbCBkYXRhIGlu dG8sIGxpa2UgdGhpcyB3ZSBjYW4gc2tpcCB0aGlzIGFyZWEgd2hlbgo+ID4gZHVtcGluZyB2bWNv cmUuCj4gPgo+ID4gQWJvdmUgaXMgd2h5IHdlIHRyeSB0byBtZW1ibG9jayByZXNlcnZlIHRoZSB3 aG9sZSBsb3cgMU0uIFdlIGRvbid0IHdhbnQKPiA+IHRvIHVzZSBpdCwganVzdCBkb24ndCB3YW50 IGFueW9uZSB0byB1c2UgaXQgaW4gMXN0IGtlcm5lbC4KPiA+Cj4gPiA+Cj4gPiA+IEkgcHJvcG9z ZSB0aGF0IHRoZSByaWdodCBzb2x1dGlvbiBpcyB0byBnaXZlIGxvdy1tZW1vcnktcmVzZXJ2aW5n IGNvZGUgcGF0aHMgdHdvIGNoYW5jZXMgdG8gZG8gd2hhdCB0aGV5IG5lZWQ6IG9uY2UgYXQgdGhl IHZlcnkgYmVnaW5uaW5nIGFuZCBvbmNlIGFmdGVyIEVGSSBib290IHNlcnZpY2VzIGFyZSBmcmVl ZC4KPiA+ID4KPiA+ID4gQWx0ZXJuYXRpdmVseSwganVzdCByZXNlcnZlICphbGwqIG90aGVyd2lz ZSB1bnVzZWQgc3ViIDFNIG1lbW9yeSB1cCBmcm9udCwgdGhlbiByZWxlYXNlIGl0IHJpZ2h0IGFm dGVyIHJlbGVhc2luZyBib290IHNlcnZpY2VzLCBhbmQgdGhlbiBpbnZva2UgdGhlIHNwZWNpYWwg Y2FzZXMgZXhhY3RseSBvbmNlLgo+ID4KPiA+IEkgYW0gbm90IHN1cmUgaWYgSSBnb3QgYm90aCBz dWdnZXN0ZWQgd2F5cyBjbGVhcmx5LiBUaGV5IGxvb2sgYSBsaXR0bGUKPiA+IGNvbXBsaWNhdGVk IGluIG91ciBjYXNlLiBBcyBJIGV4cGxhaW5lZCBhdCBhYm92ZSwgd2Ugd2FudCB0aGUgd2hvbGUg bG93Cj4gPiAxTSBsb2NrZWQgdXAsIG5vdCBvbmUgcGllY2Ugb3Igc29tZSBwaWVjZXMgb2YgaXQu Cj4gCj4gTXkgc2Vjb25kIHN1Z2dlc3Rpb24gaXMgcHJvYmFibHkgdGhlIGJldHRlciBvbmUuICBI ZXJlIGl0IGlzLCBjb25jcmV0ZWx5Ogo+IAo+IFRoZSBlYXJseSAocHJlLWZyZWVfZWZpX2Jvb3Rf c2VydmljZXMpIGNvZGUganVzdCByZXNlcnZlcyBhbGwKPiBhdmFpbGFibGUgc3ViLTFNIG1lbW9y eSB1bmNvbmRpdGlvbmFsbHksIGJ1dCBpdCBzcGVjaWFsbHkgbWFya3MgaXQgYXMKPiByZXNlcnZl ZC1idXQtYXZhaWxhYmxlLWxhdGVyLiAgV2Ugc3RvcCBhbGxvY2F0aW5nIHRoZSB0cmFtcG9saW5l IHBhZ2UKPiBhdCB0aGlzIHN0YWdlLgo+IAo+IEluIGZyZWVfZWZpX2Jvb3Rfc2VydmljZXMsIGlu c3RlYWQgb2YgKmZyZWVpbmcqIHRoZSBzdWItMU0gbWVtb3J5LCB3ZQo+IHN0aWNrIGl0IGluIHRo ZSBwaWxlIG9mIHJlc2VydmVkIG1lbW9yeSBjcmVhdGVkIGluIHRoZSBlYXJseSBzdGVwLgo+IFRo aXMgbWF5IGludm9sdmUgc3BsaXR0aW5nIGEgYmxvY2ssIGtpbmQgb2YgbGlrZSB0aGUgY3VycmVu dAo+IHRyYW1wb2xpbmUgbGF0ZSBhbGxvY2F0aW9uIHdvcmtzLgo+IAo+IFRoZW4sICphZnRlciog ZnJlZV9lZmlfYm9vdF9zZXJ2aWNlcygpLCB3ZSBydW4gYSBzaW5nbGUgYmxvY2sgb2YgY29kZQo+ IHRoYXQgbGV0cyBldmVyeXRoaW5nIHRoYXQgd2FudHMgc3ViLTFNIGNvZGUgY2xhaW0gc29tZS4g IFRoaXMgbWVhbnMKPiB0aGF0IHRoZSB0cmFtcG9saW5lIGdldHMgYWxsb2NhdGVkIGFuZCwgaWYg Y3Jhc2hrZXJuZWwgd2FudHMgdG8gY2xhaW0KPiBldmVyeXRoaW5nIGVsc2UsIGl0IGNhbi4gIEFm dGVyIHRoYXQsIGV2ZXJ5dGhpbmcgc3RpbGwgdW5jbGFpbWVkIGdldHMKPiBmcmVlZC4KCnZvaWQg X19pbml0IHNldHVwX2FyY2goY2hhciAqKmNtZGxpbmVfcCkKewouLi4KCWVmaV9yZXNlcnZlX2Jv b3Rfc2VydmljZXMoKTsKCWU4MjBfX21lbWJsb2NrX2FsbG9jX3Jlc2VydmVkX21wY19uZXcoKTsK I2lmZGVmIENPTkZJR19YODZfQ0hFQ0tfQklPU19DT1JSVVBUSU9OCiAgICAgICAgc2V0dXBfYmlv c19jb3JydXB0aW9uX2NoZWNrKCk7CiNlbmRpZgogICAgICAgIHJlc2VydmVfcmVhbF9tb2RlKCk7 ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ICAgIAoKICAgICAgICB0cmltX3BsYXRmb3JtX21lbW9yeV9yYW5nZXMoKTsKICAgICAgICB0cmlt X2xvd19tZW1vcnlfcmFuZ2UoKTsKLi4uCn0KCkFmdGVyIGVmaV9yZXNlcnZlX2Jvb3Rfc2Vydmlj ZXMoKSwgdGhlcmUgYXJlIHNldmVyYWwgZnVuY3Rpb24gY2FsbGluZyB0bwpyZXF1aXJlIG1lbW9y eSByZXNlcnZhdGlvbiB1bmRlciBsb3cgMU0uCgoKYXNtbGlua2FnZSBfX3Zpc2libGUgdm9pZCBf X2luaXQgX19ub19zYW5pdGl6ZV9hZGRyZXNzIHN0YXJ0X2tlcm5lbCh2b2lkKSAgICAgICAgICAg ICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAgICAg ICAgICAKewouLi4KCXNldHVwX2FyY2goJmNvbW1hbmRfbGluZSk7Ci4uLgoJbW1faW5pdCgpOwoJ CS0tPiBtZW1faW5pdCgpOwoJCQkgLS0+bWVtYmxvY2tfZnJlZV9hbGwoKTsKCi4uLgojaWZkZWYg Q09ORklHX1g4NgogICAgICAgIGlmIChlZmlfZW5hYmxlZChFRklfUlVOVElNRV9TRVJWSUNFUykp CiAgICAgICAgICAgICAgICBlZmlfZW50ZXJfdmlydHVhbF9tb2RlKCk7CgkJCS0tPmVmaV9mcmVl X2Jvb3Rfc2VydmljZXMoKTsKCQkJCS0tPm1lbWJsb2NrX2ZyZWVfbGF0ZSgpOwojZW5kaWYKLi4u Cn0KClNvIGZyb20gdGhlIGNvZGUgZmxvdywgd2UgY2FuIHNlZSB0aGF0IGJ1ZGR5IGFsbG9jYXRv ciBpcyBidWlsdCBpbgptbV9pbml0KCkgd2hpY2ggcHV0cyBhbGwgbWVtb3J5IGZyb20gbWVtYmxv Y2subWVtb3J5IGV4Y2x1ZGluZwptZW1ibG9jay5yZXNlcnZlZCBpbnRvIGJ1ZGR5LiBBbmQgbXVj aCBsYXRlciwgd2UgY2FsbAplZmlfZnJlZV9ib290X3NlcnZpY2VzKCkgdG8gcmVsZWFzZSB0aG9z ZSByZXNlcnZlZCBlZmkgYm9vdCBtZW1vcnkgaW50bwpidWRkeSB0b28uCgpBcmUgeW91IHN1Z2dl c3Rpbmcgd2Ugc2hvdWxkIGRvIHRoZSBtZW1vcnkgcmVzZXJ2YXRpb24gZnJvbSBsb3cgMU0KYWZ0 ZXIgZWZpX2ZyZWVfYm9vdF9zZXJ2aWNlcygpPyBUbyByZXF1aXJlIG1lbW9yeSBwYWdlcyBmcm9t IGJ1ZGR5IGZvcgp0aGVtPyBQbGVhc2UgaGVscCBwb2ludCBvdXQgbXkgbWlzdW5kZXJzdGFuZGlu ZyBpZiBoYXZlIGFueS4KCldpdGggbXkgdW5kZXJzdGFuZGluZywgaW4gbm9uLWVmaSBjYXNlLCB3 ZSBoYXZlIGRvbmUgdGhlIG1lbW9yeQpyZXNlcnZhdGlvbiB3aXRoIG1lbWJsb2NrX3Jlc2VydmUo KSwgZS5nCmU4MjBfX21lbWJsb2NrX2FsbG9jX3Jlc2VydmVkX21wY19uZXcsIHJlc2VydmVfcmVh bF9tb2RlKCkgYXJlIGNhbGxpbmcKdG8gZG8uIEp1c3QgZWZpX3Jlc2VydmV8ZnJlZV9ib290X3Nl cnZpY2VzKCkgYnJlYWsgdGhlbSB3aGVuIGVmaSBpcwplbmFibGVkLiBXZSBjYW4gZG8gdGhlbSBh Z2FpbiBpbiBlZmlfZnJlZV9ib290X3NlcnZpY2VzKCkganVzdCBsaWtlIHRoZQpyZWFsX21vZGUg cmVzZXJ2YXRpb24gZG9lcy4KClRoYW5rcwpCYW9xdWFuCgoKX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX18Ka2V4ZWMgbWFpbGluZyBsaXN0CmtleGVjQGxpc3Rz LmluZnJhZGVhZC5vcmcKaHR0cDovL2xpc3RzLmluZnJhZGVhZC5vcmcvbWFpbG1hbi9saXN0aW5m by9rZXhlYwo=