[Ocfs2-tools-devel] [PATCH 7/6] libocfs2: Catch memalign()s that will abort older glibcs. with description)

[Joel Becker]

[Caught this on the PPCs -- Joel ]

Older glibcs (before 2007/07, this includes the glibc in el5) would
abort if __libc_memalign() couldn't allocate the memory.  That's
obviously a bogus behavior, but we have to handle it.

It's simple, though.  We try with malloc() first.  If that succeeds, we
know the memory is there and retry with posix_memalign().

Signed-off-by: Joel Becker <joel.becker at oracle.com>
---
 libocfs2/memory.c |   14 ++++++++++++++
 1 files changed, 14 insertions(+), 0 deletions(-)

diff --git a/libocfs2/memory.c b/libocfs2/memory.c
index 589e114..a61fe42 100644
--- a/libocfs2/memory.c
+++ b/libocfs2/memory.c
@@ -102,9 +102,23 @@ errcode_t ocfs2_malloc_blocks(io_channel *channel, int num_blocks,
 {
 	errcode_t ret;
 	int blksize;
+	size_t bytes;
 	void **pp = (void **)ptr;
+	void *tmp;
 
 	blksize = io_get_blksize(channel);
+	if (((unsigned long long)num_blocks * blksize) > SIZE_MAX)
+		return OCFS2_ET_NO_MEMORY;
+	bytes = num_blocks * blksize;
+
+	/*
+	 * Older glibcs abort when they can't memalign() something.
+	 * Ugh!  Check with malloc() first.
+	 */
+	tmp = malloc(bytes);
+	if (!tmp)
+		return OCFS2_ET_NO_MEMORY;
+	free(tmp);
 
 	ret = posix_memalign(pp, blksize, num_blocks * blksize);
 	if (!ret)
-- 
1.6.3

-- 

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Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127