On 2020-01-09 22:37, Zhiqiang Liu wrote: > > In MKDEV macro, if mi is larger than MINORMASK, the major will be > affected by mi. For example, set dev = MKDEV(2, (1U << MINORBITS)), > then MAJOR(dev) will be equal to 3, incorrectly. > > Here, we mask mi with MINORMASK in MKDEV macro. > > Signed-off-by: Zhiqiang Liu <liuzhiqiang26@xxxxxxxxxx> > --- > include/linux/kdev_t.h | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/include/linux/kdev_t.h b/include/linux/kdev_t.h > index 85b5151911cf..40a9423720b2 100644 > --- a/include/linux/kdev_t.h > +++ b/include/linux/kdev_t.h > @@ -9,7 +9,7 @@ > > #define MAJOR(dev) ((unsigned int) ((dev) >> MINORBITS)) > #define MINOR(dev) ((unsigned int) ((dev) & MINORMASK)) > -#define MKDEV(ma,mi) (((ma) << MINORBITS) | (mi)) > +#define MKDEV(ma, mi) (((ma) << MINORBITS) | ((mi) & MINORMASK)) > > #define print_dev_t(buffer, dev) \ > sprintf((buffer), "%u:%u\n", MAJOR(dev), MINOR(dev)) Shouldn't the users of MKDEV() be fixed instead of changing the MKDEV() definition? Thanks, Bart.
