From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.3]) by smtp.subspace.kernel.org (Postfix) with ESMTP id E72041E3DE8; Tue, 7 Jan 2025 11:28:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.3 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736249303; cv=none; b=NtXhvBe439Eyuaqg1eojVjv+Ynu3NL9gsqaIBiKgOPeHXU+4hrhDyD0kvdFxGMnYXOe7TpcoxRwwmdOFirNO5tW+lLq60rxnTIWV867LPdDJcGECSU4h54zbuEuN6yeQUDisSDQNClUYOsPjMOuvHDq8K3j5gGSnqlSVkFobXlw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736249303; c=relaxed/simple; bh=2Jsy14ptUvEwniOA7t/I1F6b5Vz0seLSJSLe1vRRe40=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NPIDA2ISvTZOPntyX7oY9mvg8fbh7xUc5ehrQl7mfninJEMywNm7J/q4sUIqE146WXTCHr2p+8IcuJD2+elHFNfSQ0DimAbd0fGq52OpK8iFK4dJdumDnoVrCF4NNV7mFTUjKUZHeF/2hv/Ap8eh1FvGVYTckIKaZBxW1CaRbRY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=V5VnlfZl; arc=none smtp.client-ip=220.197.31.3 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="V5VnlfZl" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:From: Content-Type; bh=RyL7ZLpB9GQfRNru39Mn/5KSUHCmIgDmRKvxXbeOV9c=; b=V5VnlfZlXRDyarqaww/mD3WK7E56l+2tBA2zTMCHjWJqBwJcBLumi1eWbcI+jq 56MCSlJ/GhoQiC+yFFTr2/QScRXNGk0mW+bIXWSN8j1Z8ZTSow7tx81LqKZJuOgl WRIa6/DaVrN4ksll++Iq06lLc/m/remBVP/WekL9AVq5o= Received: from [192.168.174.52] (unknown []) by gzga-smtp-mtada-g0-4 (Coremail) with SMTP id _____wD3sY2cD31ndhi3EQ--.19568S2; Tue, 07 Jan 2025 19:27:26 +0800 (CST) Message-ID: <96b3a0f7-f144-4f2a-9f84-82c31d8ec23e@163.com> Date: Tue, 7 Jan 2025 19:27:24 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [v8] misc: pci_endpoint_test: Fix overflow of bar_size To: Niklas Cassel Cc: manivannan.sadhasivam@linaro.org, kw@linux.com, kishon@kernel.org, arnd@arndb.de, gregkh@linuxfoundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, rockswang7@gmail.com References: <20250104151652.1652181-1-18255117159@163.com> Content-Language: en-US From: Hans Zhang <18255117159@163.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CM-TRANSID:_____wD3sY2cD31ndhi3EQ--.19568S2 X-Coremail-Antispam: 1Uf129KBjvJXoWxCF4xXrWUZFWDGF1UCw4xXrb_yoW5Zr15pr ZIkF4SyF4jqF9rG392qwn0qF9ayFsrJryDXFW5Kw1Yvrn0vFyxtF1rC3yUG3yfurn7uF4a qFsxJa18ur17AaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x07jTJP_UUUUU= X-CM-SenderInfo: rpryjkyvrrlimvzbiqqrwthudrp/xtbBDwDNo2d9DwUPPgAAsA On 2025/1/7 18:32, Niklas Cassel wrote: >>>> --- >>>> drivers/misc/pci_endpoint_test.c | 12 +++++++++--- >>>> 1 file changed, 9 insertions(+), 3 deletions(-) >>>> >>>> diff --git a/drivers/misc/pci_endpoint_test.c b/drivers/misc/pci_endpoint_test.c >>>> index 3aaaf47fa4ee..50d4616119af 100644 >>>> --- a/drivers/misc/pci_endpoint_test.c >>>> +++ b/drivers/misc/pci_endpoint_test.c >>>> @@ -280,10 +280,11 @@ static int pci_endpoint_test_bar_memcmp(struct pci_endpoint_test *test, >>>> static bool pci_endpoint_test_bar(struct pci_endpoint_test *test, >>>> enum pci_barno barno) >>>> { >>>> - int j, bar_size, buf_size, iters, remain; >>>> void *write_buf __free(kfree) = NULL; >>>> void *read_buf __free(kfree) = NULL; >>>> struct pci_dev *pdev = test->pdev; >>>> + int j, buf_size, iters, remain; >>>> + resource_size_t bar_size; >> >> Fix resource_size_t to u64 bar_size. >> u64 bar_size; >> >>>> if (!test->bar[barno]) >>>> return false; >>>> @@ -307,13 +308,18 @@ static bool pci_endpoint_test_bar(struct pci_endpoint_test *test, >>>> if (!read_buf) >>>> return false; >>>> - iters = bar_size / buf_size; >>>> + if (IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT)) { >>>> + remain = do_div(bar_size, buf_size); >>>> + iters = bar_size; >>>> + } else { >>>> + iters = bar_size / buf_size; >>>> + remain = bar_size % buf_size; >>>> + } >> >> Removed IS_ENABLED(CONFIG_PHYS_ADDR_T_64BIT), Execute the following code. >> >> remain = do_div(bar_size, buf_size); >> iters = bar_size; > > Perhaps keep it as resource_size_t and then cast it to u64 in the do_div() > call? Hi Niklas, resource_size_t bar_size; remain = do_div((u64)bar_size, buf_size); It works for the arm platform. arch/arm/include/asm/div64.h static inline uint32_t __div64_32(uint64_t *n, uint32_t base) { register unsigned int __base asm("r4") = base; register unsigned long long __n asm("r0") = *n; register unsigned long long __res asm("r2"); unsigned int __rem; asm( __asmeq("%0", "r0") __asmeq("%1", "r2") __asmeq("%2", "r4") "bl __do_div64" : "+r" (__n), "=r" (__res) : "r" (__base) : "ip", "lr", "cc"); __rem = __n >> 32; *n = __res; return __rem; } #define __div64_32 __div64_32 #define do_div(n, base) __div64_32(&(n), base) For X86 platforms, do_div is a macro definition, and the first parameter does not define its type. If the macro definition is replaced directly, an error will be reported in the ubuntu20.04 release. resource_size_t bar_size; remain = do_div((u64)bar_size, buf_size); arch/x86/include/asm/div64.h #define do_div(n, base) \ ({ \ unsigned long __upper, __low, __high, __mod, __base; \ __base = (base); \ if (__builtin_constant_p(__base) && is_power_of_2(__base)) { \ __mod = n & (__base - 1); \ n >>= ilog2(__base); \ } else { \ asm("" : "=a" (__low), "=d" (__high) : "A" (n));\ __upper = __high; \ if (__high) { \ __upper = __high % (__base); \ __high = __high / (__base); \ } \ asm("divl %2" : "=a" (__low), "=d" (__mod) \ : "rm" (__base), "0" (__low), "1" (__upper)); \ asm("" : "=A" (n) : "a" (__low), "d" (__high)); \ } \ __mod; \ }) Best regards Hans