[PATCH 1/1] irq/matrix: Fix memory overallocation

[PATCH 1/1] irq/matrix: Fix memory overallocation

[Michael Kelley]

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 as the size of 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.

Signed-off-by: Michael Kelley <mikelley@microsoft.com>
---
 kernel/irq/matrix.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 6e6d467..1f0985a 100644
--- 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;
-- 
1.8.3.1

[tip:irq/urgent] irq/matrix: Fix memory overallocation

[tip-bot for Michael Kelley]

Commit-ID:  57f01796f14fecf00d330fe39c8d2477ced9cd79
Gitweb:     https://git.kernel.org/tip/57f01796f14fecf00d330fe39c8d2477ced9cd79
Author:     Michael Kelley <mikelley@microsoft.com>
AuthorDate: Thu, 1 Nov 2018 00:35:05 +0000
Committer:  Thomas Gleixner <tglx@linutronix.de>
CommitDate: Thu, 1 Nov 2018 10:00:38 +0100

irq/matrix: Fix memory overallocation

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

---
 kernel/irq/matrix.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/irq/matrix.c b/kernel/irq/matrix.c
index 6e6d467f3dec..1f0985adf193 100644
--- 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;