From 5a0e3ad6af8660be21ca98a971cd00f331318c05 Mon Sep 17 00:00:00 2001 From: Tejun Heo Date: Wed, 24 Mar 2010 17:04:11 +0900 Subject: include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo Guess-its-ok-by: Christoph Lameter Cc: Ingo Molnar Cc: Lee Schermerhorn --- net/netlabel/netlabel_unlabeled.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/netlabel/netlabel_unlabeled.c') diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 852d9d7976b9..d7ea2cf390b7 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -43,6 +43,7 @@ #include #include #include +#include #include #include #include -- cgit v1.2.2 From b914f3a2a35812545f773645f340d7c075e5b64d Mon Sep 17 00:00:00 2001 From: Paul Moore Date: Thu, 1 Apr 2010 10:43:57 +0000 Subject: netlabel: Fix several rcu_dereference() calls used without RCU read locks The recent changes to add RCU lock verification to rcu_dereference() calls caught out a problem with netlbl_unlhsh_hash(), see below. =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- net/netlabel/netlabel_unlabeled.c:246 invoked rcu_dereference_check() without protection! This patch fixes this problem as well as others like it in the NetLabel code. Also included in this patch is the identification of future work to eliminate the RCU read lock in netlbl_domhsh_add(), but in the interest of getting this patch out quickly that work will happen in another patch to be finished later. Thanks to Eric Dumazet and Paul McKenney for their help in understanding the recent RCU changes. Signed-off-by: Paul Moore Reported-by: David Howells CC: Eric Dumazet CC: Paul E. McKenney Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/netlabel/netlabel_unlabeled.c | 66 +++++++++++---------------------------- 1 file changed, 19 insertions(+), 47 deletions(-) (limited to 'net/netlabel/netlabel_unlabeled.c') diff --git a/net/netlabel/netlabel_unlabeled.c b/net/netlabel/netlabel_unlabeled.c index 852d9d7976b9..3b4fde7622a3 100644 --- a/net/netlabel/netlabel_unlabeled.c +++ b/net/netlabel/netlabel_unlabeled.c @@ -114,6 +114,9 @@ struct netlbl_unlhsh_walk_arg { /* updates should be so rare that having one spinlock for the entire * hash table should be okay */ static DEFINE_SPINLOCK(netlbl_unlhsh_lock); +#define netlbl_unlhsh_rcu_deref(p) \ + rcu_dereference_check(p, rcu_read_lock_held() || \ + lockdep_is_held(&netlbl_unlhsh_lock)) static struct netlbl_unlhsh_tbl *netlbl_unlhsh = NULL; static struct netlbl_unlhsh_iface *netlbl_unlhsh_def = NULL; @@ -235,15 +238,13 @@ static void netlbl_unlhsh_free_iface(struct rcu_head *entry) * Description: * This is the hashing function for the unlabeled hash table, it returns the * bucket number for the given device/interface. The caller is responsible for - * calling the rcu_read_[un]lock() functions. + * ensuring that the hash table is protected with either a RCU read lock or + * the hash table lock. * */ static u32 netlbl_unlhsh_hash(int ifindex) { - /* this is taken _almost_ directly from - * security/selinux/netif.c:sel_netif_hasfn() as they do pretty much - * the same thing */ - return ifindex & (rcu_dereference(netlbl_unlhsh)->size - 1); + return ifindex & (netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->size - 1); } /** @@ -253,7 +254,8 @@ static u32 netlbl_unlhsh_hash(int ifindex) * Description: * Searches the unlabeled connection hash table and returns a pointer to the * interface entry which matches @ifindex, otherwise NULL is returned. The - * caller is responsible for calling the rcu_read_[un]lock() functions. + * caller is responsible for ensuring that the hash table is protected with + * either a RCU read lock or the hash table lock. * */ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex) @@ -263,7 +265,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex) struct netlbl_unlhsh_iface *iter; bkt = netlbl_unlhsh_hash(ifindex); - bkt_list = &rcu_dereference(netlbl_unlhsh)->tbl[bkt]; + bkt_list = &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]; list_for_each_entry_rcu(iter, bkt_list, list) if (iter->valid && iter->ifindex == ifindex) return iter; @@ -271,33 +273,6 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface(int ifindex) return NULL; } -/** - * netlbl_unlhsh_search_iface_def - Search for a matching interface entry - * @ifindex: the network interface - * - * Description: - * Searches the unlabeled connection hash table and returns a pointer to the - * interface entry which matches @ifindex. If an exact match can not be found - * and there is a valid default entry, the default entry is returned, otherwise - * NULL is returned. The caller is responsible for calling the - * rcu_read_[un]lock() functions. - * - */ -static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface_def(int ifindex) -{ - struct netlbl_unlhsh_iface *entry; - - entry = netlbl_unlhsh_search_iface(ifindex); - if (entry != NULL) - return entry; - - entry = rcu_dereference(netlbl_unlhsh_def); - if (entry != NULL && entry->valid) - return entry; - - return NULL; -} - /** * netlbl_unlhsh_add_addr4 - Add a new IPv4 address entry to the hash table * @iface: the associated interface entry @@ -308,8 +283,7 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_search_iface_def(int ifindex) * Description: * Add a new address entry into the unlabeled connection hash table using the * interface entry specified by @iface. On success zero is returned, otherwise - * a negative value is returned. The caller is responsible for calling the - * rcu_read_[un]lock() functions. + * a negative value is returned. * */ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface, @@ -349,8 +323,7 @@ static int netlbl_unlhsh_add_addr4(struct netlbl_unlhsh_iface *iface, * Description: * Add a new address entry into the unlabeled connection hash table using the * interface entry specified by @iface. On success zero is returned, otherwise - * a negative value is returned. The caller is responsible for calling the - * rcu_read_[un]lock() functions. + * a negative value is returned. * */ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface, @@ -391,8 +364,7 @@ static int netlbl_unlhsh_add_addr6(struct netlbl_unlhsh_iface *iface, * Description: * Add a new, empty, interface entry into the unlabeled connection hash table. * On success a pointer to the new interface entry is returned, on failure NULL - * is returned. The caller is responsible for calling the rcu_read_[un]lock() - * functions. + * is returned. * */ static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex) @@ -415,10 +387,10 @@ static struct netlbl_unlhsh_iface *netlbl_unlhsh_add_iface(int ifindex) if (netlbl_unlhsh_search_iface(ifindex) != NULL) goto add_iface_failure; list_add_tail_rcu(&iface->list, - &rcu_dereference(netlbl_unlhsh)->tbl[bkt]); + &netlbl_unlhsh_rcu_deref(netlbl_unlhsh)->tbl[bkt]); } else { INIT_LIST_HEAD(&iface->list); - if (rcu_dereference(netlbl_unlhsh_def) != NULL) + if (netlbl_unlhsh_rcu_deref(netlbl_unlhsh_def) != NULL) goto add_iface_failure; rcu_assign_pointer(netlbl_unlhsh_def, iface); } @@ -548,8 +520,7 @@ unlhsh_add_return: * * Description: * Remove an IP address entry from the unlabeled connection hash table. - * Returns zero on success, negative values on failure. The caller is - * responsible for calling the rcu_read_[un]lock() functions. + * Returns zero on success, negative values on failure. * */ static int netlbl_unlhsh_remove_addr4(struct net *net, @@ -611,8 +582,7 @@ static int netlbl_unlhsh_remove_addr4(struct net *net, * * Description: * Remove an IP address entry from the unlabeled connection hash table. - * Returns zero on success, negative values on failure. The caller is - * responsible for calling the rcu_read_[un]lock() functions. + * Returns zero on success, negative values on failure. * */ static int netlbl_unlhsh_remove_addr6(struct net *net, @@ -1547,8 +1517,10 @@ int netlbl_unlabel_getattr(const struct sk_buff *skb, struct netlbl_unlhsh_iface *iface; rcu_read_lock(); - iface = netlbl_unlhsh_search_iface_def(skb->skb_iif); + iface = netlbl_unlhsh_search_iface(skb->skb_iif); if (iface == NULL) + iface = rcu_dereference(netlbl_unlhsh_def); + if (iface == NULL || !iface->valid) goto unlabel_getattr_nolabel; switch (family) { case PF_INET: { -- cgit v1.2.2