From: scameron@beardog.cce.hp.com
To: xfs@oss.sgi.com
Cc: scameron@beardog.cce.hp.com
Subject: xfstests, weird looking code in src/resvtest.c
Date: Tue, 17 Jun 2014 11:20:44 -0500 [thread overview]
Message-ID: <20140617162044.GL29459@beardog.cce.hp.com> (raw)
This code in xfstests src/resvtest.c looks pretty strange:
...
32 char *readbuffer, *writebuffer;
...
70 readbuffer = memalign(psize, bsize);
71 writebuffer = memalign(psize, bsize);
72 if (!readbuffer || !writebuffer) {
73 perror("open");
74 exit(1);
75 }
76 memset(writebuffer, 'A', sizeof(writebuffer));
^^^ writebuffer is a pointer, so using sizeof(writebuffer) here is
odd. Is it intentional to put either 4 or 8 A's into writebuffer
depending on sizeof a pointer? Seems unlikely.
110 while (++n < iterations) {
111 char *p;
112 int numerrors;
113
114 if (write(writefd, writebuffer, sizeof(writebuffer)) < 0) {
115 perror("write");
116 exit(1);
117 }
So that write will write sizeof a pointer's worth of whatever's in writebuffer.
Intentional? Again, seems unlikely.
This seems like maybe somebody initially declared writebuffer as an array, but
later went back and changed it to a pointer, but forgot to fixup everywhere that
referred to sizeof(writebuffer).
I would have sent a patch but I'm not sure what this code is trying to do.
gcc 4.4.7 (what comes with RHEL6u5) doesn't warn about this, but 4.8.3 does.
-- steve
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next reply other threads:[~2014-06-17 16:21 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-06-17 16:20 scameron [this message]
2014-06-17 23:06 ` xfstests, weird looking code in src/resvtest.c Dave Chinner
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