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[90.8.158.167]) by smtp.gmail.com with ESMTPSA id a2sm1731908wrs.55.2020.10.27.05.17.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 27 Oct 2020 05:17:37 -0700 (PDT) From: Bartosz Golaszewski To: Andy Shevchenko , Sumit Semwal , Gustavo Padovan , =?utf-8?q?Christian_K=C3=B6nig?= , Mauro Carvalho Chehab , Borislav Petkov , Tony Luck , James Morse , Robert Richter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , Daniel Vetter , Alexander Shishkin , Linus Walleij , "Michael S . Tsirkin" , Jason Wang , Christoph Lameter , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , Jaroslav Kysela , Takashi Iwai Cc: linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, linaro-mm-sig@lists.linaro.org, linux-kernel@vger.kernel.org, linux-edac@vger.kernel.org, linux-gpio@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-mm@kvack.org, alsa-devel@alsa-project.org, Bartosz Golaszewski Subject: [PATCH 1/8] mm: slab: provide krealloc_array() Date: Tue, 27 Oct 2020 13:17:18 +0100 Message-Id: <20201027121725.24660-2-brgl@bgdev.pl> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027121725.24660-1-brgl@bgdev.pl> References: <20201027121725.24660-1-brgl@bgdev.pl> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org From: Bartosz Golaszewski When allocating an array of elements, users should check for multiplication overflow or preferably use one of the provided helpers like: kmalloc_array(). There's no krealloc_array() counterpart but there are many users who use regular krealloc() to reallocate arrays. Let's provide an actual krealloc_array() implementation. Signed-off-by: Bartosz Golaszewski Acked-by: Vlastimil Babka --- include/linux/slab.h | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/include/linux/slab.h b/include/linux/slab.h index dd6897f62010..0e6683affee7 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -592,6 +592,17 @@ static inline void *kmalloc_array(size_t n, size_t size, gfp_t flags) return __kmalloc(bytes, flags); } +static __must_check inline void * +krealloc_array(void *p, size_t new_n, size_t new_size, gfp_t flags) +{ + size_t bytes; + + if (unlikely(check_mul_overflow(new_n, new_size, &bytes))) + return NULL; + + return krealloc(p, bytes, flags); +} + /** * kcalloc - allocate memory for an array. The memory is set to zero. * @n: number of elements.