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6c3c721275
With gcc 7 the compiler checks for sprintf() the maxium possible resulting
string based on the used datatypes.
Example:
struct vol {
...
char bus_id[9];
...
}
sprintf(vol->bus_id, "0.%x.%04x", ssid, vol_parm->devno);
The compiler can prove that "ssid" comes from "u8" and "vol_parm->devno"
from "u16". Therefore the resulting maximum string can be 0.ff.ffff which
requires 10 bytes.
This leads to the following warning:
dfi_s390mv.c: In function 'volumes_init':
dfi_s390mv.c:243:45: warning: '__builtin___snprintf_chk' output may be
truncated before the last format character [-Wformat-truncation=]
snprintf(vol->bus_id, sizeof(vol->bus_id), "0.%x.%04x", ssid,
^~~~~~~~~~~
In file included from /usr/include/stdio.h:936:0,
from dfi_s390mv.c:15:
/usr/include/bits/stdio2.h:64:10: note: '__builtin___snprintf_chk' output
between 9 and 10 bytes into a destination of size 9
return __builtin___snprintf_chk (__s, __n, __USE_FORTIFY_LEVEL - 1,
^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
__bos (__s), __fmt, __va_arg_pack ());
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
To get rid of the warning use 10 instead of 9 bytes for the bus_id.
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>