xfstests, weird looking code in src/resvtest.c
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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Quoted 30 lines · On Tue, Jun 17, 2014 at 11:20:44AM -0500, [email protected] wrote:
This code in xfstests
src/resvtest.clooks 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 }
76memset(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) {
115perror("write");
116 exit(1);
117 }So that write will write sizeof a pointer's worth of whatever's in writebuffer. Intentional? Again, seems unlikely.
Quoted 7 lines
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.
There's a recent patch on the fstests list ([email protected]) that fixes this that I haven't picked up yet.
For actual test harness issues, you should use [email protected] now, not [email protected]...
Cheers,
Dave.
Signature · 7 lines
Dave Chinner [email protected] _______________________________________________ xfs mailing list [email protected] http://oss.sgi.com/mailman/listinfo/xfs