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From:   Bartosz Golaszewski <brgl@bgdev.pl>
To:     Jonathan Cameron <jic23@kernel.org>,
        Lars-Peter Clausen <lars@metafoo.de>,
        Peter Meerwald-Stadler <pmeerw@pmeerw.net>,
        Michal Simek <michal.simek@xilinx.com>
Cc:     linux-iio@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Bartosz Golaszewski <bgolaszewski@baylibre.com>
Subject: [PATCH v2 1/4] device: provide devm_krealloc_array()
Date:   Mon,  2 Nov 2020 15:22:25 +0100
Message-Id: <20201102142228.14949-2-brgl@bgdev.pl>
In-Reply-To: <20201102142228.14949-1-brgl@bgdev.pl>
References: <20201102142228.14949-1-brgl@bgdev.pl>
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From: Bartosz Golaszewski <bgolaszewski@baylibre.com>

When allocating an array of elements, users should check for
multiplication overflow or preferably use one of the provided helpers
like: devm_kmalloc_array().

This provides devm_krealloc_array() for users who want to reallocate
managed arrays.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
---
 include/linux/device.h | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/include/linux/device.h b/include/linux/device.h
index 5ed101be7b2e..e77203faea55 100644
--- a/include/linux/device.h
+++ b/include/linux/device.h
@@ -226,6 +226,17 @@ static inline void *devm_kmalloc_array(struct device *dev,
 
 	return devm_kmalloc(dev, bytes, flags);
 }
+static inline void *
+devm_krealloc_array(struct device *dev, void *ptr, size_t new_n,
+		    size_t new_size, gfp_t gfp)
+{
+	size_t bytes;
+
+	if (unlikely(check_mul_overflow(new_n, new_size, &bytes)))
+		return NULL;
+
+	return devm_krealloc(dev, ptr, bytes, gfp);
+}
 static inline void *devm_kcalloc(struct device *dev,
 				 size_t n, size_t size, gfp_t flags)
 {
-- 
2.29.1