when run make, show:
swapon.c:135:3: warning: 'p' may be used uninitialized in this function
[-Wmaybe-uninitialized]
memcpy(p, buf, BUF_SIZE);
^~~~~~~~~~~~~~~~~~~~~~~~
This's a fake uninitialized warning.
gcc think the 'p' can be used uninitialized at here when verb is
TEST_MWRITE_BEFORE_AND_MWRITE_AFTER:
case TEST_MWRITE_BEFORE_AND_MWRITE_AFTER:
memcpy(p, buf, BUF_SIZE);
break;
But, if verb is TEST_MWRITE_BEFORE_AND_MWRITE_AFTER, the 'p' will be
initialized by:
switch (verb) {
case TEST_MWRITE_BEFORE_AND_MWRITE_AFTER:
case TEST_MWRITE_BEFORE:
p = mmap(NULL, BUF_SIZE, PROT_WRITE | PROT_READ, MAP_SHARED,
Silent the warning by initializing p to NULL anyway.
Signed-off-by: Sun Ke <sunke32@huawei.com>
Reviewed-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
.sa_handler = handle_signal,
};
enum verbs verb = TEST_SWAPON;
- void *p;
+ void *p = NULL;
ssize_t sz;
int fd = -1;
int ret, c;