From: Karel Zak <kzak@redhat.com>
Date: Tue, 13 Nov 2012 09:36:25 +0000 (+0100)
Subject: lscpu: make read_topology() more robust to avoid SIGFPE
X-Git-Tag: v2.23-rc1~529
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=d4bfa64d44e0515c59e5274d2384dedd9f9d4cc8;p=thirdparty%2Futil-linux.git

lscpu: make read_topology() more robust to avoid SIGFPE

Signed-off-by: Karel Zak <kzak@redhat.com>
---

diff --git a/sys-utils/lscpu.c b/sys-utils/lscpu.c
index 5b1a0afeeb..a111561dcb 100644
--- a/sys-utils/lscpu.c
+++ b/sys-utils/lscpu.c
@@ -627,16 +627,26 @@ read_topology(struct lscpu_desc *desc, int num)
 
 		/* threads within one core */
 		nthreads = CPU_COUNT_S(setsize, thread_siblings);
+		if (!nthreads)
+			nthreads = 1;
+
 		/* cores within one socket */
 		ncores = CPU_COUNT_S(setsize, core_siblings) / nthreads;
-		/* number of sockets within one book.
-		 * Because of odd / non-present cpu maps and to keep
-		 * calculation easy we make sure that nsockets and
-		 * nbooks is at least 1.
+		if (!ncores)
+			ncores = 1;
+
+		/* number of sockets within one book.  Because of odd /
+		 * non-present cpu maps and to keep calculation easy we make
+		 * sure that nsockets and nbooks is at least 1.
 		 */
-		nsockets = desc->ncpus / nthreads / ncores ?: 1;
+		nsockets = desc->ncpus / nthreads / ncores;
+		if (!nsockets)
+			nsockets = 1;
+
 		/* number of books */
-		nbooks = desc->ncpus / nthreads / ncores / nsockets ?: 1;
+		nbooks = desc->ncpus / nthreads / ncores / nsockets;
+		if (!nbooks)
+			nbooks = 1;
 
 		/* all threads, see also read_basicinfo()
 		 * -- fallback for kernels without
@@ -644,6 +654,7 @@ read_topology(struct lscpu_desc *desc, int num)
 		 */
 		if (!desc->nthreads)
 			desc->nthreads = nbooks * nsockets * ncores * nthreads;
+
 		/* For each map we make sure that it can have up to ncpuspos
 		 * entries. This is because we cannot reliably calculate the
 		 * number of cores, sockets and books on all architectures.