linux-kernel - [PATCH] Avoid zero size allocation in cache_k8

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Message-Id: <1179341042.6870.280.camel@cunning>
Date:	Wed, 16 May 2007 14:44:02 -0400
From:	Ben Collins <ben.collins@...ntu.com>
To:	linux-kernel@...r.kernel.org
Cc:	Linus Torvalds <torvalds@...l.org>
Subject: [PATCH] Avoid zero size allocation in cache_k8_northbridges()

kmalloc for flush_words resulted in zero size allocation when no
k8_northbridges existed. Short circuit the code path for this case.

Also remove uneeded zeroing of num_k8_northbridges just after checking
if it is zero.

Signed-off-by: Ben Collins <bcollins@...ntu.com>

diff --git a/arch/x86_64/kernel/k8.c b/arch/x86_64/kernel/k8.c
index bc11b32..7377ccb 100644
--- a/arch/x86_64/kernel/k8.c
+++ b/arch/x86_64/kernel/k8.c
@@ -39,10 +39,10 @@ int cache_k8_northbridges(void)
 {
 	int i;
 	struct pci_dev *dev;
+
 	if (num_k8_northbridges)
 		return 0;
 
-	num_k8_northbridges = 0;
 	dev = NULL;
 	while ((dev = next_k8_northbridge(dev)) != NULL)
 		num_k8_northbridges++;
@@ -52,6 +52,11 @@ int cache_k8_northbridges(void)
 	if (!k8_northbridges)
 		return -ENOMEM;
 
+	if (!num_k8_northbridges) {
+		k8_northbridges[0] = NULL;
+		return 0;
+	}
+
 	flush_words = kmalloc(num_k8_northbridges * sizeof(u32), GFP_KERNEL);
 	if (!flush_words) {
 		kfree(k8_northbridges);


-- 
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