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[82.69.66.36]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-48febe585absm20016505e9.19.2026.05.15.12.16.15 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 15 May 2026 12:16:17 -0700 (PDT) Date: Fri, 15 May 2026 20:16:13 +0100 From: David Laight To: Zong Li Cc: pjw@kernel.org, palmer@dabbelt.com, aou@eecs.berkeley.edu, alex@ghiti.fr, debug@rivosinc.com, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v3] riscv: cif: reduce shadow stack size limit from 4GB to 2GB Message-ID: <20260515201613.243ea49b@pumpkin> In-Reply-To: References: <20260514075036.1432352-1-zong.li@sifive.com> <20260514095605.2c7d8761@pumpkin> <20260515102411.4d3e868a@pumpkin> X-Mailer: Claws Mail 4.1.1 (GTK 3.24.38; arm-unknown-linux-gnueabihf) MIME-Version: 1.0 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260515_121620_296865_156BD33F X-CRM114-Status: GOOD ( 30.34 ) X-BeenThere: linux-riscv@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Sender: "linux-riscv" Errors-To: linux-riscv-bounces+linux-riscv=archiver.kernel.org@lists.infradead.org T24gRnJpLCAxNSBNYXkgMjAyNiAyMjoyOTowNSArMDgwMApab25nIExpIDx6b25nLmxpQHNpZml2 ZS5jb20+IHdyb3RlOgoKPiBPbiBGcmksIE1heSAxNSwgMjAyNiBhdCA1OjI04oCvUE0gRGF2aWQg TGFpZ2h0Cj4gPGRhdmlkLmxhaWdodC5saW51eEBnbWFpbC5jb20+IHdyb3RlOgo+ID4KPiA+IE9u IEZyaSwgMTUgTWF5IDIwMjYgMTE6NDI6NDUgKzA4MDAKPiA+IFpvbmcgTGkgPHpvbmcubGlAc2lm aXZlLmNvbT4gd3JvdGU6Cj4gPiAgCj4gPiA+IE9uIFRodSwgTWF5IDE0LCAyMDI2IGF0IDQ6NTbi gK9QTSBEYXZpZCBMYWlnaHQgIAo+ID4gLi4gIAo+ID4gPiA+IEkgYWxzbyBkb24ndCB1bmRlcnN0 YW5kIHRoZSByYXRpb25hbCBmb3IganVzdCAvMiBhbmQgdGhlIDJHIHVwcGVyIGxpbWl0Lgo+ID4g PiA+IFlvdSBuZWVkIDUxMiBuZXN0ZWQgZnVuY3Rpb24gY2FsbHMgdG8gZXZlbiB1c2UgNGsuCj4g PiA+ID4gVGhhdCB3b3VsZCBoYXZlIHRvIGJlIHF1aXRlIGRlZXAgcmVjdXJzaW9uLiAgCj4gPiA+ Cj4gPiA+IER1cmluZyB0aGUgZGlzY3Vzc2lvbnMgYWJvdXQgdGhlIEFSTSBHQ1MgdjMgc2VyaWVz LCBjb21tdW5pdHkgcG9pbnRlZAo+ID4gPiBvdXQgdGhhdCBhIDRHIHNoYWRvdyBzdGFjayBtaWdo dCBiZSB0b28gbGFyZ2UuIFRoaXMgc2l6ZSBpcyBoYXJkIHRvCj4gPiA+IHN1cHBvcnQgaW4gbWVt b3J5LWNvbnN0cmFpbmVkIGVudmlyb25tZW50cyBsaWtlIEFuZHJvaWQuIEhvd2V2ZXIsIHRoZQo+ ID4gPiBzaXplIGNhbm5vdCBiZSB0b28gc21hbGwgZWl0aGVyLCBvciB3ZSBtaWdodCBmYWNlIHN0 YWNrIG92ZXJmbG93Cj4gPiA+IGlzc3Vlcy4gQXQgdGhhdCB0aW1lLCBhIHBlcmZlY3Qgc2l6ZSB3 YXMgbm90IGRlY2lkZWQuICAKPiA+Cj4gPiBJdCBpcyBvbmx5IFZBIG5vdCByZWFsIG1lbW9yeSBz byBzaG91bGRuJ3QgbWFrZSBtdWNoIGRpZmZlcmVuY2UgdG8gbWVtb3J5Cj4gPiB1c2UgKGV4Y2Vw dCBmb3Igbm9tbXUgd2hlcmUgdGhlIGFjdHVhbCBtZW1vcnkgaGFzIHRvIGJlIGFsbG9jYXRlZCku Cj4gPiAgCj4gCj4gWW91IHJhaXNlIGEgdmFsaWQgcG9pbnQgdGhhdCBzaGFkb3cgc3RhY2tzIGFy ZSBwcmltYXJpbHkgYSBWQQo+IGFsbG9jYXRpb24uIEhvd2V2ZXIsIGluIExpbnV4LCB0aGUgbWVt b3J5IG92ZXJjb21taXQgbWVjaGFuaXNtIGNyZWF0ZXMKPiBhIHByYWN0aWNhbCBsaW5rIGJldHdl ZW4gVkEgYWxsb2NhdGlvbiBhbmQgcGh5c2ljYWwgbWVtb3J5IGNhcGFjaXR5Lgo+IEFzIEkgbWVu dGlvbmVkIGluIHRoZSBjb21taXQgbWVzc2FnZSwgbWVtb3J5IGFsbG9jYXRpb24gd2lsbCBmYWls IHdoZW4KPiB0aGUgb3ZlcmNvbW1pdCBtb2RlIGlzIHNldCB0byBPVkVSQ09NTUlUX0dVRVNTIG9y IE9WRVJDT01NSVRfTkVWRVIuCj4gCj4gSW4gX192bV9lbm91Z2hfbWVtb3J5Ogo+ICAgICAgICAg aWYgKHBhZ2VzID4gdG90YWxyYW1fcGFnZXMoKSArIHRvdGFsX3N3YXBfcGFnZXMpCj4gICAgICAg ICAgICAgICAgIGdvdG8gZXJyb3I7Cj4gCj4gTWFueSBwYWdlIHJlcXVlc3RzIGZvciBWQSB3aWxs IGZhaWwgaWYgdGhlIHJlcXVlc3RlZCBzaXplIGV4Y2VlZHMgdGhlCj4gc3lzdGVtJ3MgdG90YWwg UkFNIHBsdXMgU3dhcC4gT24gbWVtb3J5LWNvbnN0cmFpbmVkIHN5c3RlbXMsCj4gYWxsb2NhdGlu ZyBhIG1hc3NpdmUgNEdCIHNoYWRvdyBzdGFjayBwZXIgdGhyZWFkIHdvdWxkIGltbWVkaWF0ZWx5 Cj4gdHJpZ2dlciB0aGlzIGVycm9yLgoKQnV0IHJlZHVjaW5nIHRoZSBzaXplIGJ5IGhhbGYgbWFr ZXMgbGl0dGxlIGRpZmZlcmVuY2UuCllvdSdkIG5lZWQgYSBtdWNoIGJpZ2dlciByZWR1Y3Rpb24g dG8gbWFrZSBhbnkgcmVhbCBkaWZmZXJlbmNlLgoKLS0gRGF2aWQKCj4gCj4gPiBCdXQgMzJiaXQg cHJvZ3JhbXMgd2l0aCBsb3RzIG9mIHRocmVhZHMgY2FuIHJ1biBvdXQgb2YgVkEuCj4gPiBJbmNy ZWFzaW5nIHRoZSBzdGFjayBWQSBzaXplIGJ5IDUwJSBtaWdodCBldmVuIGdpdmUgcHJvYmxlbXMg Zm9yIDY0Yml0Cj4gPiBwcm9ncmFtcyAtIGlmIHRoZXkgYXJlIGFscmVhZHkgcmVkdWNpbmcgdGhl IHRocmVhZCBzdGFjayBzaXplIGF2b2lkCj4gPiBydW5uaW5nIG91dCBvZiBWQS4KPiA+Cj4gPiBJ J3ZlIG5vdCBjaGVja2VkLCBidXQgcHRocmVhZF9hdHRyX3NldHN0YWNrc2l6ZSgpIHNldHMgYSBs aW1pdCBmb3IgdGhlCj4gPiB0aHJlYWQgc3RhY2sgc2l6ZSAod2hpY2ggd291bGQgb3RoZXJ3aXNl IGRlZmF1bHQgc28gcmxpbWl0KFNUQUNLKSkuCj4gPiBJIGRvbid0IGJlbGlldmUgaXQgc2hvdWxk IHVwZGF0ZSB0aGUgcmxpbWl0IHZhbHVlIGl0c2VsZi4KPiA+IEluIHdoaWNoIGNhc2UgeW91IGFy ZSB1c2luZyB0aGUgd3Jvbmcgc2l6ZS4KPiA+Cj4gPiBCdXQgZm9yIGEgdGhyZWFkIHdpdGggYSB2 ZXJ5IHJlZHVjZWQgc3RhY2sgKHNheSAxMjhrKSB5b3UgcHJvYmFibHkgb25seQo+ID4gbmVlZCAx IHBhZ2Ugb2Ygc2hhZG93IHN0YWNrLCBhbnkgbW9yZSBjb3VsZCBlYXNpbHkgbGVhZCB0byBydW5u aW5nIG91dAo+ID4gb2YgVkEuCj4gPgo+ID4gLS0gRGF2aWQgIAo+IAoKCl9fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fCmxpbnV4LXJpc2N2IG1haWxpbmcgbGlz dApsaW51eC1yaXNjdkBsaXN0cy5pbmZyYWRlYWQub3JnCmh0dHA6Ly9saXN0cy5pbmZyYWRlYWQu b3JnL21haWxtYW4vbGlzdGluZm8vbGludXgtcmlzY3YK