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authorThadeu Lima de Souza Cascardo <cascardo@holoscopio.com>2009-12-14 18:00:30 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2009-12-15 08:53:27 -0800
commit4ae717da8d18839487485f6ae608b8542790fdd3 (patch)
tree9db3390a593c0335f6944fd094c8fd8f52455be8
parent603c4ba96be998a8dd7a6f9b23681c49acdf4b64 (diff)
drivers/char/misc.c: clear allocation bit in minor bitmap when device register fails
If there's a failure creating the device (because there's already one with the same name, for example), the current implementation does not clear the bit for the allocated minor and that number is lost for future allocations. Second, the test currently in misc_deregister is broken, since it does not test for the 0 minor. Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@holoscopio.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--drivers/char/misc.c8
1 files changed, 5 insertions, 3 deletions
diff --git a/drivers/char/misc.c b/drivers/char/misc.c
index 281edefffa0b..a3a02f6303c8 100644
--- a/drivers/char/misc.c
+++ b/drivers/char/misc.c
@@ -214,6 +214,9 @@ int misc_register(struct miscdevice * misc)
misc->this_device = device_create(misc_class, misc->parent, dev,
misc, "%s", misc->name);
if (IS_ERR(misc->this_device)) {
+ int i = misc->minor;
+ if (i < DYNAMIC_MINORS && i >= 0)
+ misc_minors[i>>3] &= ~(1 << (i & 7));
err = PTR_ERR(misc->this_device);
goto out;
}
@@ -248,9 +251,8 @@ int misc_deregister(struct miscdevice *misc)
mutex_lock(&misc_mtx);
list_del(&misc->list);
device_destroy(misc_class, MKDEV(MISC_MAJOR, misc->minor));
- if (i < DYNAMIC_MINORS && i>0) {
- misc_minors[i>>3] &= ~(1 << (misc->minor & 7));
- }
+ if (i < DYNAMIC_MINORS && i >= 0)
+ misc_minors[i>>3] &= ~(1 << (i & 7));
mutex_unlock(&misc_mtx);
return 0;
}