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([94.75.70.14]) by smtp.gmail.com with ESMTPSA id j29-20020ac2551d000000b004f1383d57ecsm1563284lfk.202.2023.06.06.12.55.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Jun 2023 12:55:19 -0700 (PDT) X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 111a1ffe-04a4-11ee-b232-6b7b168915f2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1686081320; x=1688673320; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=7TGArhQdSQX8UOhmIpz6TBiOEP22ajLMR7OWHR6Nu4A=; b=O/XGaXCCKoTPUoZQ8DfwCH/WP0x17xGqKCKSMRVwnICDn5x6+ADpIfUG2vJJxCaDcN QFOtJe3BevRTdoRxJ1ihm4+sKe3JcEDxsdXFX3YdPQ+YGsT14pmvjZIUNfm3DpzQyQV1 sVz6ntBRlEqDBMyEDqmt/Phn47dsMM5EKpGP6bW/ObW/xhPDtskv/EzeaGrwm5Dh9Eup JIF3S1CRyf0y4cuYGUuv7/j7E4ppdu/YTOVcJg1lcvjR2QlxzsRNkH4IjTHkfq3C7COe oSiKG8EWvk4/M86K/1vgJf3wJayoGlvoweT7MwP38fVyJfMtgei/ecNoMkSJWBjYzHCn ImcA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1686081320; x=1688673320; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=7TGArhQdSQX8UOhmIpz6TBiOEP22ajLMR7OWHR6Nu4A=; b=Lw8rQ7xi596fGcX8gatd/heJjKMhtjlKlX+wRczZqo/L/Otlc2SB+SHOHeW2p/d1Zy xqckWYjiPUmQBHazSeVhTM61/0xKJuiHWx084BQoGL67NUGQo6E9XQpi1o7XNQ7psCYd DWJ3T/wdilUkPIAnoKhxtaFe+ouzSSnD8O+VJmxsY+VVIhMscSV5sDhH+SaKVUb5CKPF 1fzJxHpTY4UlHKWstGl9q5yDkx8XZcaS3OA/F/mqrNMBHTbu/dBHPYl6PW5gqBxvjdp9 b3A3hKhprd/YyCt8LGB5N87otJVBrrScxBsPJXf8KccIP+EcpEKFm6cFOCCvyKjtHZM1 +Z4w== X-Gm-Message-State: AC+VfDwW3CMGc1+FIyp8ObX2N27ittrKIOILkX3H3ufrH7k5EmcvDM9A l7iCDA+2d23YLSUjxQMSl6m38m22unQ= X-Google-Smtp-Source: ACHHUZ57sB49WRMNcaI7ZfKQo7gAicuQco4hCa6Kjlrsr1+WkBj5jKHEmupI5ZX9n2A1vFpA6QoZyQ== X-Received: by 2002:a19:a416:0:b0:4f6:116d:6d26 with SMTP id q22-20020a19a416000000b004f6116d6d26mr1219679lfc.42.1686081319616; Tue, 06 Jun 2023 12:55:19 -0700 (PDT) From: Oleksii Kurochko To: xen-devel@lists.xenproject.org Cc: Jan Beulich , Andrew Cooper , Oleksii Kurochko , Bob Eshleman , Alistair Francis , Connor Davis Subject: [PATCH v1 1/8] xen/riscv: make sure that identity mapping isn't bigger then page size Date: Tue, 6 Jun 2023 22:55:09 +0300 Message-Id: <4ad639bed6b8aa6cee34288a7ce154db21d761b5.1686080337.git.oleksii.kurochko@gmail.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: References: MIME-Version: 1.0 Signed-off-by: Oleksii Kurochko Acked-by: Alistair Francis --- xen/arch/riscv/xen.lds.S | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/xen/arch/riscv/xen.lds.S b/xen/arch/riscv/xen.lds.S index 878130f313..74afbaab9b 100644 --- a/xen/arch/riscv/xen.lds.S +++ b/xen/arch/riscv/xen.lds.S @@ -20,6 +20,7 @@ SECTIONS . = XEN_VIRT_START; _start = .; .text : { + _idmap_start = .; _stext = .; /* Text section */ *(.text.header) @@ -35,6 +36,7 @@ SECTIONS *(.gnu.warning) . = ALIGN(POINTER_ALIGN); _etext = .; /* End of text section */ + _idmap_end = .; } :text . = ALIGN(PAGE_SIZE); @@ -174,3 +176,10 @@ ASSERT(!SIZEOF(.got), ".got non-empty") ASSERT(!SIZEOF(.got.plt), ".got.plt non-empty") ASSERT(_end - _start <= MB(2), "Xen too large for early-boot assumptions") + +/* + * We require that Xen is loaded at a page boundary, so this ensures that any + * code running on the identity map cannot cross a page boundary. + */ +ASSERT(IS_ALIGNED(_idmap_start, PAGE_SIZE), "_idmap_start should be page-aligned") +ASSERT(_idmap_end - _idmap_start <= PAGE_SIZE, "Identity mapped code is larger than a page size")