irq/matrix: Fix memory overallocation

[ Upstream commit 57f01796f14fecf00d330fe39c8d2477ced9cd79 ]

IRQ_MATRIX_SIZE is the number of longs needed for a bitmap, multiplied by
the size of a long, yielding a byte count. But it is used to size an array
of longs, which is way more memory than is needed.

Change IRQ_MATRIX_SIZE so it is just the number of longs needed and the
arrays come out the correct size.

Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator")
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: KY Srinivasan <kys@microsoft.com>
Link: https://lkml.kernel.org/r/1541032428-10392-1-git-send-email-mikelley@microsoft.com
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 92337703ca9fdd0bd026fa4a0965f74a696e663b..30cc217b863184989987f2fa76c76c8bc9a082b4 100644 (file)
--- a/kernel/irq/matrix.c
+++ b/kernel/irq/matrix.c
@@ -8,7 +8,7 @@
 #include <linux/cpu.h>
 #include <linux/irq.h>
 
-#define IRQ_MATRIX_SIZE        (BITS_TO_LONGS(IRQ_MATRIX_BITS) * sizeof(unsigned long))
+#define IRQ_MATRIX_SIZE        (BITS_TO_LONGS(IRQ_MATRIX_BITS))
 
 struct cpumap {
        unsigned int            available;