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char_dev: Fix off-by-one bugs in find_dynamic_major()

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CHRDEV_MAJOR_DYN_END and CHRDEV_MAJOR_DYN_EXT_END are valid major
numbers. So fix the loop iteration to include them in the search for
free major numbers.

While at it, also remove a redundant if condition ("cd->major != i"),
as it will never be true.

Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Srivatsa S. Bhat 2018-02-05 18:25:09 -08:00 committed by Greg Kroah-Hartman
parent bd329f028f
commit 652d703b21
1 changed files with 3 additions and 3 deletions
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6
fs/char_dev.c
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@ -67,18 +67,18 @@ static int find_dynamic_major(void)
int i;
struct char_device_struct *cd;
for (i = ARRAY_SIZE(chrdevs)-1; i > CHRDEV_MAJOR_DYN_END; i--) {
for (i = ARRAY_SIZE(chrdevs)-1; i >= CHRDEV_MAJOR_DYN_END; i--) {
if (chrdevs[i] == NULL)
return i;
}
for (i = CHRDEV_MAJOR_DYN_EXT_START;
i > CHRDEV_MAJOR_DYN_EXT_END; i--) {
i >= CHRDEV_MAJOR_DYN_EXT_END; i--) {
for (cd = chrdevs[major_to_index(i)]; cd; cd = cd->next)
if (cd->major == i)
break;
if (cd == NULL || cd->major != i)
if (cd == NULL)
return i;
}