In the test program
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/ioctl.h>
#include <linux/cdrom.h>
main(int argc, char *argv[])
{
dvd_struct buf;
int fd;
fd = open("/dev/sr0", O_RDONLY);
if (fd < 0) {
perror("open");
return -1;
}
memset(&buf, 0, sizeof(buf));
buf.type = DVD_STRUCT_MANUFACT;
if (ioctl(fd, DVD_READ_STRUCT, &buf) < 0) {
perror("DVD_READ_STRUCT");
return -2;
}
printf("Got len %d, value '%*s'\n", buf.manufact.len,
buf.manufact.len, buf.manufact.value);
return 0;
}
the ioctl always fails with EIO. The test code seems too simple to be wrong,
so perhaps something is fishy in dvd_read_manufact() in the kernel,
http://lxr.linux.no/linux+v2.6.38/drivers/cdrom/cdrom.c#L1908
I care about this because this affects some games which are just trying
to verify that their DVD is inserted.
Rumor has it that the change
- if (s->manufact.len < 0 || s->manufact.len > 2048) {
+ if (s->manufact.len < 0 || s->manufact.len > 2052) {
cdinfo(CD_WARNING, "Received invalid manufacture info length"
" (%d)\n", s->manufact.len);
ret = -EIO;
} else {
- memcpy(s->manufact.value, &buf[4], s->manufact.len);
+ memcpy(s->manufact.value, &buf[4],
+ s->manufact.len > 2052 ? 2048 : s->manufact.len);
makes the ioctl function as expected, and lets the games detect
their dvd.
Do you have an upstream version of this bug?