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[37.24.206.209]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a80f414e3basm63498266b.164.2024.08.13.04.49.40 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 13 Aug 2024 04:49:40 -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: 2024c93b-596a-11ef-8776-851b0ebba9a2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=google; t=1723549781; x=1724154581; darn=lists.xenproject.org; h=content-transfer-encoding:autocrypt:content-language:cc:to:subject :from:user-agent:mime-version:date:message-id:from:to:cc:subject :date:message-id:reply-to; bh=+hkf4y+gpixNGnjs6JeKccrNDQA3i4qzSsHd16s5Lpg=; b=Uu1qq+Aqh3+IsFEo33s5ZyfmGo769d6/FsgfyjGN7s7lrzLedq4TN6onTX0SQZzxw5 e+M6WoJamJrFgjhNxpgdqMoCxYyCyNNjB5eQ/EKEIKmJM5Q/JZKQJxoLAlIUOjtLL+gt rDpME7q+WE/Mt6VoNwrO/QzfXiINW1ONzfZz0u/TxnUniSEPXHYFdcXnUpEEYtdxIQmw XUPn14K3PeKCY5Tau/f1eNZrnFjtnjTz98vKBWgSPtu+WNpGPOVCzU3uqeeqK0kP6qu7 /jfcWWj6v07R9yCmqf0cvcYcHuP3E2/xR9r0cTEZ1uGE9oOgVFwYNJckVKlLcth7wOJN lYzQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1723549781; x=1724154581; h=content-transfer-encoding:autocrypt:content-language:cc:to:subject :from:user-agent:mime-version:date:message-id:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=+hkf4y+gpixNGnjs6JeKccrNDQA3i4qzSsHd16s5Lpg=; b=lBAeGoD1+/9uTO/WA3unqXcC1D84S2r8q2cMQqtR0bTEECjqNYcDHsBskO9Qvlwks8 7Om0JtztfhurImAzqXdndRUaP2oti2B4m6CQn6zxL8MJfbWET4vTNq9vr+HSQOyXIOh/ cYUD4ykA++DFwyr1UCEuXjcTtSqUCvQLGlYHzuz0H+JEb19U4Myp7BJ1grnHRCusn3AY Czb3EmlEC8lgm6osbFp5UNOcgnqtnnUYxFL25SwFyySg09Hbo8rFKyufDUWPyfN890Wg U/wDGngAvsgjDyAbjE6YbShHt/Nrr7DulbXX8lsT/0qxkkCTiN0yI4nRh1FRNES0pcyI m9Cg== X-Gm-Message-State: AOJu0YzMpj4oDNrBZdYSGIKgX/Qnkv1ijWDbslrhjLZ/ay3LLQ/c0MTu iglx0zA4mNJ/DzI5tc3lekfw7uZVc6N79DwLeLeg7zxvdJa7fEztPdVP7HhBYmvE1Cb1UnHEOI8 = X-Google-Smtp-Source: AGHT+IFS4/5paSEhcDIDoSpuyx6/P2Ua++MbMsbnTk8oRa+7TrYJwRu8qOms77yo1eS/J7hRjwpGXA== X-Received: by 2002:a17:907:9801:b0:a7a:ab8a:386 with SMTP id a640c23a62f3a-a80ed2d496bmr222874166b.63.1723549780563; Tue, 13 Aug 2024 04:49:40 -0700 (PDT) Message-ID: <5b097aa2-7ced-4971-bd6e-96618bb6f2df@suse.com> Date: Tue, 13 Aug 2024 13:49:39 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird From: Jan Beulich Subject: [PATCH v2] Arm: correct FIXADDR_TOP To: "xen-devel@lists.xenproject.org" Cc: Julien Grall , Stefano Stabellini , Volodymyr Babchuk , Bertrand Marquis , Michal Orzel , Oleksii Kurochko Content-Language: en-US Autocrypt: addr=jbeulich@suse.com; keydata= xsDiBFk3nEQRBADAEaSw6zC/EJkiwGPXbWtPxl2xCdSoeepS07jW8UgcHNurfHvUzogEq5xk hu507c3BarVjyWCJOylMNR98Yd8VqD9UfmX0Hb8/BrA+Hl6/DB/eqGptrf4BSRwcZQM32aZK 7Pj2XbGWIUrZrd70x1eAP9QE3P79Y2oLrsCgbZJfEwCgvz9JjGmQqQkRiTVzlZVCJYcyGGsD /0tbFCzD2h20ahe8rC1gbb3K3qk+LpBtvjBu1RY9drYk0NymiGbJWZgab6t1jM7sk2vuf0Py O9Hf9XBmK0uE9IgMaiCpc32XV9oASz6UJebwkX+zF2jG5I1BfnO9g7KlotcA/v5ClMjgo6Gl MDY4HxoSRu3i1cqqSDtVlt+AOVBJBACrZcnHAUSuCXBPy0jOlBhxPqRWv6ND4c9PH1xjQ3NP nxJuMBS8rnNg22uyfAgmBKNLpLgAGVRMZGaGoJObGf72s6TeIqKJo/LtggAS9qAUiuKVnygo 3wjfkS9A3DRO+SpU7JqWdsveeIQyeyEJ/8PTowmSQLakF+3fote9ybzd880fSmFuIEJldWxp Y2ggPGpiZXVsaWNoQHN1c2UuY29tPsJgBBMRAgAgBQJZN5xEAhsDBgsJCAcDAgQVAggDBBYC AwECHgECF4AACgkQoDSui/t3IH4J+wCfQ5jHdEjCRHj23O/5ttg9r9OIruwAn3103WUITZee e7Sbg12UgcQ5lv7SzsFNBFk3nEQQCACCuTjCjFOUdi5Nm244F+78kLghRcin/awv+IrTcIWF hUpSs1Y91iQQ7KItirz5uwCPlwejSJDQJLIS+QtJHaXDXeV6NI0Uef1hP20+y8qydDiVkv6l IreXjTb7DvksRgJNvCkWtYnlS3mYvQ9NzS9PhyALWbXnH6sIJd2O9lKS1Mrfq+y0IXCP10eS FFGg+Av3IQeFatkJAyju0PPthyTqxSI4lZYuJVPknzgaeuJv/2NccrPvmeDg6Coe7ZIeQ8Yj t0ARxu2xytAkkLCel1Lz1WLmwLstV30g80nkgZf/wr+/BXJW/oIvRlonUkxv+IbBM3dX2OV8 AmRv1ySWPTP7AAMFB/9PQK/VtlNUJvg8GXj9ootzrteGfVZVVT4XBJkfwBcpC/XcPzldjv+3 HYudvpdNK3lLujXeA5fLOH+Z/G9WBc5pFVSMocI71I8bT8lIAzreg0WvkWg5V2WZsUMlnDL9 mpwIGFhlbM3gfDMs7MPMu8YQRFVdUvtSpaAs8OFfGQ0ia3LGZcjA6Ik2+xcqscEJzNH+qh8V m5jjp28yZgaqTaRbg3M/+MTbMpicpZuqF4rnB0AQD12/3BNWDR6bmh+EkYSMcEIpQmBM51qM EKYTQGybRCjpnKHGOxG0rfFY1085mBDZCH5Kx0cl0HVJuQKC+dV2ZY5AqjcKwAxpE75MLFkr wkkEGBECAAkFAlk3nEQCGwwACgkQoDSui/t3IH7nnwCfcJWUDUFKdCsBH/E5d+0ZnMQi+G0A nAuWpQkjM1ASeQwSHEeAWPgskBQL While reviewing a RISC-V patch cloning the Arm code, I noticed an off-by-1 here: FIX_PMAP_{BEGIN,END} being an inclusive range and FIX_LAST being the same as FIX_PMAP_END, FIXADDR_TOP cannot derive from FIX_LAST alone, or else the BUG_ON() in virt_to_fix() would trigger if FIX_PMAP_END ended up being used. While touching this area also add a check for fixmap and boot FDT area to not only not overlap, but to have at least one (unmapped) page in between. Fixes: 4f17357b52f6 ("xen/arm: add Persistent Map (PMAP) infrastructure") Signed-off-by: Jan Beulich Reviewed-by: Michal Orzel --- v2: Adjust FIXADDR_TOP instead. Add BUILD_BUG_ON() as suggested by Michal. --- a/xen/arch/arm/include/asm/fixmap.h +++ b/xen/arch/arm/include/asm/fixmap.h @@ -18,7 +18,7 @@ #define FIX_LAST FIX_PMAP_END #define FIXADDR_START FIXMAP_ADDR(0) -#define FIXADDR_TOP FIXMAP_ADDR(FIX_LAST) +#define FIXADDR_TOP FIXMAP_ADDR(FIX_LAST + 1) #ifndef __ASSEMBLY__ --- a/xen/arch/arm/mmu/setup.c +++ b/xen/arch/arm/mmu/setup.c @@ -128,6 +128,12 @@ static void __init __maybe_unused build_ #undef CHECK_SAME_SLOT #undef CHECK_DIFFERENT_SLOT + + /* + * Fixmaps must not overlap with boot FDT mapping area. Make sure there's + * at least one guard page in between. + */ + BUILD_BUG_ON(FIXADDR_TOP >= BOOT_FDT_VIRT_START); } lpae_t __init pte_of_xenaddr(vaddr_t va)