From 02589f60510030a3c1496e7a8c511e4f674ef5ff Mon Sep 17 00:00:00 2001 From: Henrique de Moraes Holschuh Date: Sat, 2 Aug 2008 15:10:57 -0300 Subject: [PATCH] rfkill: detect bogus double-registering (v2) Detect and abort with -EEXIST if rfkill_register is called twice on the same rfkill struct. And WARN_ON(it) for good measure. While at it, flag when we are adding the first switch of a type, we will need that information later. Signed-off-by: Henrique de Moraes Holschuh Acked-by: Ivo van Doorn Cc: Johannes Berg Signed-off-by: John W. Linville --- net/rfkill/rfkill.c | 29 ++++++++++++++++++++++++++++- 1 file changed, 28 insertions(+), 1 deletion(-) diff --git a/net/rfkill/rfkill.c b/net/rfkill/rfkill.c index 35a9994e2339..1f23de20a85e 100644 --- a/net/rfkill/rfkill.c +++ b/net/rfkill/rfkill.c @@ -525,17 +525,44 @@ static struct class rfkill_class = { .dev_uevent = rfkill_dev_uevent, }; +static int rfkill_check_duplicity(const struct rfkill *rfkill) +{ + struct rfkill *p; + unsigned long seen[BITS_TO_LONGS(RFKILL_TYPE_MAX)]; + + memset(seen, 0, sizeof(seen)); + + list_for_each_entry(p, &rfkill_list, node) { + if (p == rfkill) { + WARN_ON(1); + return -EEXIST; + } + set_bit(p->type, seen); + } + + /* 0: first switch of its kind */ + return test_bit(rfkill->type, seen); +} + static int rfkill_add_switch(struct rfkill *rfkill) { + int error; + mutex_lock(&rfkill_mutex); + error = rfkill_check_duplicity(rfkill); + if (error < 0) + goto unlock_out; + rfkill_toggle_radio(rfkill, rfkill_states[rfkill->type], 0); list_add_tail(&rfkill->node, &rfkill_list); + error = 0; +unlock_out: mutex_unlock(&rfkill_mutex); - return 0; + return error; } static void rfkill_remove_switch(struct rfkill *rfkill) -- 2.30.2