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/core/dev.c | 1 + 1 file changed, 1 insertion(+) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 59d4394d2ce8..1c8a0ce473a8 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -80,6 +80,7 @@ #include #include #include +#include #include #include #include -- cgit v1.2.3 From 8728c544a9cbdcb0034aa5c45706c5f953f030ee Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Sun, 11 Apr 2010 21:18:17 +0000 Subject: net: dev_pick_tx() fix When dev_pick_tx() caches tx queue_index on a socket, we must check socket dst_entry matches skb one, or risk a crash later, as reported by Denys Fedorysychenko, if old packets are in flight during a route change, involving devices with different number of queues. Bug introduced by commit a4ee3ce3 (net: Use sk_tx_queue_mapping for connected sockets) Reported-by: Denys Fedorysychenko Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 1c8a0ce473a8..92584bfef09b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1989,8 +1989,12 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev, if (dev->real_num_tx_queues > 1) queue_index = skb_tx_hash(dev, skb); - if (sk && sk->sk_dst_cache) - sk_tx_queue_set(sk, queue_index); + if (sk) { + struct dst_entry *dst = rcu_dereference(sk->sk_dst_cache); + + if (dst && skb_dst(skb) == dst) + sk_tx_queue_set(sk, queue_index); + } } } -- cgit v1.2.3 From 05d17608a69b3ae653ea5c9857283bef3439c733 Mon Sep 17 00:00:00 2001 From: David Howells Date: Tue, 20 Apr 2010 00:25:58 +0000 Subject: net: Fix an RCU warning in dev_pick_tx() Fix the following RCU warning in dev_pick_tx(): =================================================== [ INFO: suspicious rcu_dereference_check() usage. ] --------------------------------------------------- net/core/dev.c:1993 invoked rcu_dereference_check() without protection! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 2 locks held by swapper/0: #0: (&idev->mc_ifc_timer){+.-...}, at: [] run_timer_softirq+0x17b/0x278 #1: (rcu_read_lock_bh){.+....}, at: [] dev_queue_xmit+0x14e/0x4dc stack backtrace: Pid: 0, comm: swapper Not tainted 2.6.34-rc5-cachefs #4 Call Trace: [] lockdep_rcu_dereference+0xaa/0xb2 [] dev_queue_xmit+0x259/0x4dc [] ? dev_queue_xmit+0x14e/0x4dc [] ? trace_hardirqs_on+0xd/0xf [] ? local_bh_enable_ip+0xbc/0xc1 [] neigh_resolve_output+0x24b/0x27c [] ip6_output_finish+0x7c/0xb4 [] ip6_output2+0x256/0x261 [] ? trace_hardirqs_on+0xd/0xf [] ip6_output+0xbbc/0xbcb [] ? fib6_force_start_gc+0x2b/0x2d [] mld_sendpack+0x273/0x39d [] ? mld_sendpack+0x0/0x39d [] ? mark_held_locks+0x52/0x70 [] mld_ifc_timer_expire+0x24f/0x288 [] run_timer_softirq+0x1ec/0x278 [] ? run_timer_softirq+0x17b/0x278 [] ? mld_ifc_timer_expire+0x0/0x288 [] ? __do_softirq+0x69/0x140 [] __do_softirq+0xa2/0x140 [] call_softirq+0x1c/0x28 [] do_softirq+0x38/0x80 [] irq_exit+0x45/0x47 [] smp_apic_timer_interrupt+0x88/0x96 [] apic_timer_interrupt+0x13/0x20 [] ? __atomic_notifier_call_chain+0x0/0x86 [] ? mwait_idle+0x6e/0x78 [] ? mwait_idle+0x65/0x78 [] cpu_idle+0x4d/0x83 [] rest_init+0xb9/0xc0 [] ? rest_init+0x0/0xc0 [] start_kernel+0x392/0x39d [] x86_64_start_reservations+0xb3/0xb7 [] x86_64_start_kernel+0xe4/0xeb An rcu_dereference() should be an rcu_dereference_bh(). Signed-off-by: David Howells Acked-by: Eric Dumazet Signed-off-by: David S. Miller --- net/core/dev.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'net/core/dev.c') diff --git a/net/core/dev.c b/net/core/dev.c index 92584bfef09b..f769098774b7 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1990,7 +1990,7 @@ static struct netdev_queue *dev_pick_tx(struct net_device *dev, queue_index = skb_tx_hash(dev, skb); if (sk) { - struct dst_entry *dst = rcu_dereference(sk->sk_dst_cache); + struct dst_entry *dst = rcu_dereference_bh(sk->sk_dst_cache); if (dst && skb_dst(skb) == dst) sk_tx_queue_set(sk, queue_index); -- cgit v1.2.3