From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AG47ELuUtrX8MFeuEmG6oLEdtVXlqqxQcZFfNaPxCdVZzvguskamruenyCJKwFbBB0HBRHlPqQmT ARC-Seal: i=1; a=rsa-sha256; t=1520986728; cv=none; d=google.com; s=arc-20160816; b=HSaHSoFZYTFETKUrdsEyHlb3/aOmm40qOhV9u43G50KOT22DVn0YX8AIkPaVLEfolD SnxyqYfXqkt8FMV9yLfJwY0lKo1IO6O09iqocLD5AsM+Dvk936Icy6KCgMY4M/iAqnnw N61bFjDPBwFevvUvCEcNNSjF0T6uO9v+wUb9HCkAueOTj7c4o71/dkbrR2ZRxFik1tHG E4LrOH/MDfMZKO9OIPoWH2Nuu4TP/PAm+XFxodnaw+L17Tc4+q8KMiPhvVtxdZOGYqH6 q+gX3WQOnYQvKvUpRzqTusLI6ARmWHTX0YGBx57KZw+gG49vzRkM5VkFLETFU8UaKn2c a8WQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:cc:to:subject :delivered-to:list-id:list-subscribe:list-unsubscribe:list-help :list-post:precedence:mailing-list:arc-authentication-results; bh=mdY2p0D+b0virh/3/wlRN9oZbQIou1TZv+VAOAEbH6w=; b=HRn4uZfkfEAzaTiE5Sk9lXdK7GQ3T3kbrarGNK7PfFL85UX0O9qWl+QfyEoD2UF9ad c807pBgXGRjhw6kZWsIfk/jqYxF41Azc7C/PZT2QAHP/JW6ITe9zJQVsJGrjqHYUgs8V J5R6HAlp4gVY7flkFbS7rRffDfg8U80fy7z7kDZ3V8jZ0/hgGVpnml7co5jEhiwSnoh8 cxMb3vP3sUFlByak+2TogXj36CUhT3fqMoaKJ+TT/2PsjMmArL2DOno6qhCkq2dtFMyW fT4aCwstHzVONt5xJzidI8AskJDsSlh3dGsjSBxzyzmDfsOH9ReDfYe3JBy+71vRHMMQ cBPQ== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12565-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12565-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of kernel-hardening-return-12565-gregkh=linuxfoundation.org@lists.openwall.com designates 195.42.179.200 as permitted sender) smtp.mailfrom=kernel-hardening-return-12565-gregkh=linuxfoundation.org@lists.openwall.com; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=redhat.com Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm List-Post: List-Help: List-Unsubscribe: List-Subscribe: Subject: Re: [PATCH 4/4] gpio: Remove VLA from stmpe driver To: Phil Reid , Linus Walleij , Kees Cook , Patrice Chotard Cc: linux-gpio@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-hardening@lists.openwall.com References: <20180310001021.6437-1-labbott@redhat.com> <20180310001021.6437-5-labbott@redhat.com> <9175611d-049d-ec28-0716-e45fccfd579f@electromag.com.au> From: Laura Abbott Message-ID: <4e64bbae-e91b-f0c5-ff79-3dde8fbe2119@redhat.com> Date: Tue, 13 Mar 2018 17:18:22 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <9175611d-049d-ec28-0716-e45fccfd579f@electromag.com.au> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1594507326034109383?= X-GMAIL-MSGID: =?utf-8?q?1594870180015795328?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On 03/13/2018 02:13 AM, Phil Reid wrote: > On 10/03/2018 08:10, Laura Abbott wrote: >> The new challenge is to remove VLAs from the kernel >> (see https://lkml.org/lkml/2018/3/7/621) >> >> This patch replaces a VLA with an appropriate call to kmalloc_array. >> >> Signed-off-by: Laura Abbott >> --- >>   drivers/gpio/gpio-stmpe.c | 7 ++++++- >>   1 file changed, 6 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/gpio/gpio-stmpe.c b/drivers/gpio/gpio-stmpe.c >> index f8d7d1cd8488..b7854850bcdb 100644 >> --- a/drivers/gpio/gpio-stmpe.c >> +++ b/drivers/gpio/gpio-stmpe.c >> @@ -369,10 +369,14 @@ static irqreturn_t stmpe_gpio_irq(int irq, void *dev) >>       struct stmpe *stmpe = stmpe_gpio->stmpe; >>       u8 statmsbreg; >>       int num_banks = DIV_ROUND_UP(stmpe->num_gpios, 8); >> -    u8 status[num_banks]; >> +    u8 *status; >>       int ret; >>       int i; >> +    status = kmalloc_array(num_banks, sizeof(*status), GFP_ATOMIC); >> +    if (!status) >> +        return IRQ_NONE; >> + >>       /* >>        * the stmpe_block_read() call below, imposes to set statmsbreg >>        * with the register located at the lowest address. As STMPE1600 >> @@ -424,6 +428,7 @@ static irqreturn_t stmpe_gpio_irq(int irq, void *dev) >>           } >>       } >> +    kfree(status); >>       return IRQ_HANDLED; >>   } >> > > Doing this in an irq handler seems wrong. > Perhaps better if a buffer is pre-allocated in stmpe_gpio > > Sure, I can pre-allocate the buffer in the probe. Thanks, Laura