kernel/include, branch linux-3.9.y

nbd: correct disconnect behavior

2013-07-21T00:16:07Z

commit c378f70adbc1bbecd9e6db145019f14b2f688c7c upstream. Currently, when a disconnect is requested by the user (via NBD_DISCONNECT ioctl) the return from NBD_DO_IT is undefined (it is usually one of several error codes). This means that nbd-client does not know if a manual disconnect was performed or whether a network error occurred. Because of this, nbd-client's persist mode (which tries to reconnect after error, but not after manual disconnect) does not always work correctly. This change fixes this by causing NBD_DO_IT to always return 0 if a user requests a disconnect. This means that nbd-client can correctly either persist the connection (if an error occurred) or disconnect (if the user requested it). Signed-off-by: Paul Clements Acked-by: Rob Landley Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

futex: Take hugepages into account when generating futex_key

2013-07-13T18:39:17Z

commit 13d60f4b6ab5b702dc8d2ee20999f98a93728aec upstream. The futex_keys of process shared futexes are generated from the page offset, the mapping host and the mapping index of the futex user space address. This should result in an unique identifier for each futex. Though this is not true when futexes are located in different subpages of an hugepage. The reason is, that the mapping index for all those futexes evaluates to the index of the base page of the hugetlbfs mapping. So a futex at offset 0 of the hugepage mapping and another one at offset PAGE_SIZE of the same hugepage mapping have identical futex_keys. This happens because the futex code blindly uses page->index. Steps to reproduce the bug: 1. Map a file from hugetlbfs. Initialize pthread_mutex1 at offset 0 and pthread_mutex2 at offset PAGE_SIZE of the hugetlbfs mapping. The mutexes must be initialized as PTHREAD_PROCESS_SHARED because PTHREAD_PROCESS_PRIVATE mutexes are not affected by this issue as their keys solely depend on the user space address. 2. Lock mutex1 and mutex2 3. Create thread1 and in the thread function lock mutex1, which results in thread1 blocking on the locked mutex1. 4. Create thread2 and in the thread function lock mutex2, which results in thread2 blocking on the locked mutex2. 5. Unlock mutex2. Despite the fact that mutex2 got unlocked, thread2 still blocks on mutex2 because the futex_key points to mutex1. To solve this issue we need to take the normal page index of the page which contains the futex into account, if the futex is in an hugetlbfs mapping. In other words, we calculate the normal page mapping index of the subpage in the hugetlbfs mapping. Mappings which are not based on hugetlbfs are not affected and still use page->index. Thanks to Mel Gorman who provided a patch for adding proper evaluation functions to the hugetlbfs code to avoid exposing hugetlbfs specific details to the futex code. [ tglx: Massaged changelog ] Signed-off-by: Zhang Yi Reviewed-by: Jiang Biao Tested-by: Ma Chenggong Reviewed-by: 'Mel Gorman' Acked-by: 'Darren Hart' Cc: 'Peter Zijlstra' Link: http://lkml.kernel.org/r/000101ce71a6%24a83c5880%24f8b50980%24@com Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

perf: Fix perf mmap bugs

2013-06-27T17:39:22Z

commit 26cb63ad11e04047a64309362674bcbbd6a6f246 upstream. Vince reported a problem found by his perf specific trinity fuzzer. Al noticed 2 problems with perf's mmap(): - it has issues against fork() since we use vma->vm_mm for accounting. - it has an rb refcount leak on double mmap(). We fix the issues against fork() by using VM_DONTCOPY; I don't think there's code out there that uses this; we didn't hear about weird accounting problems/crashes. If we do need this to work, the previously proposed VM_PINNED could make this work. Aside from the rb reference leak spotted by Al, Vince's example prog was indeed doing a double mmap() through the use of perf_event_set_output(). This exposes another problem, since we now have 2 events with one buffer, the accounting gets screwy because we account per event. Fix this by making the buffer responsible for its own accounting. Reported-by: Vince Weaver Signed-off-by: Peter Zijlstra Cc: Al Viro Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/r/20130528085548.GA12193@twins.programming.kicks-ass.net Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

net_sched: restore "overhead xxx" handling

2013-06-27T17:39:02Z

[ Upstream commit 01cb71d2d47b78354358e4bb938bb06323e17498 ] commit 56b765b79 ("htb: improved accuracy at high rates") broke the "overhead xxx" handling, as well as the "linklayer atm" attribute. tc class add ... htb rate X ceil Y linklayer atm overhead 10 This patch restores the "overhead xxx" handling, for htb, tbf and act_police The "linklayer atm" thing needs a separate fix. Reported-by: Jesper Dangaard Brouer Signed-off-by: Eric Dumazet Cc: Vimalkumar Cc: Jiri Pirko Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: force a reload of first item in hlist_nulls_for_each_entry_rcu

2013-06-27T17:39:02Z

[ Upstream commit c87a124a5d5e8cf8e21c4363c3372bcaf53ea190 ] Roman Gushchin discovered that udp4_lib_lookup2() was not reloading first item in the rcu protected list, in case the loop was restarted. This produced soft lockups as in https://lkml.org/lkml/2013/4/16/37 rcu_dereference(X)/ACCESS_ONCE(X) seem to not work as intended if X is ptr->field : In some cases, gcc caches the value or ptr->field in a register. Use a barrier() to disallow such caching, as documented in Documentation/atomic_ops.txt line 114 Thanks a lot to Roman for providing analysis and numerous patches. Diagnosed-by: Roman Gushchin Signed-off-by: Eric Dumazet Reported-by: Boris Zhmurov Signed-off-by: Roman Gushchin Acked-by: Paul E. McKenney Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

udp6: Fix udp fragmentation for tunnel traffic.

2013-06-27T17:39:02Z

[ Upstream commit 1e2bd517c108816220f262d7954b697af03b5f9c ] udp6 over GRE tunnel does not work after to GRE tso changes. GRE tso handler passes inner packet but keeps track of outer header start in SKB_GSO_CB(skb)->mac_offset. udp6 fragment need to take care of outer header, which start at the mac_offset, while adding fragment header. This bug is introduced by commit 68c3316311 (GRE: Add TCP segmentation offload for GRE). Reported-by: Dmitry Kravkov Signed-off-by: Pravin B Shelar Tested-by: Dmitry Kravkov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: Block MSG_CMSG_COMPAT in send(m)msg and recv(m)msg

2013-06-27T17:39:01Z

[ Upstream commits 1be374a0518a288147c6a7398792583200a67261 and a7526eb5d06b0084ef12d7b168d008fcf516caab ] MSG_CMSG_COMPAT is (AFAIK) not intended to be part of the API -- it's a hack that steals a bit to indicate to other networking code that a compat entry was used. So don't allow it from a non-compat syscall. This prevents an oops when running this code: int main() { int s; struct sockaddr_in addr; struct msghdr *hdr; char *highpage = mmap((void*)(TASK_SIZE_MAX - 4096), 4096, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS | MAP_FIXED, -1, 0); if (highpage == MAP_FAILED) err(1, "mmap"); s = socket(AF_INET, SOCK_DGRAM, IPPROTO_UDP); if (s == -1) err(1, "socket"); addr.sin_family = AF_INET; addr.sin_port = htons(1); addr.sin_addr.s_addr = htonl(INADDR_LOOPBACK); if (connect(s, (struct sockaddr*)&addr, sizeof(addr)) != 0) err(1, "connect"); void *evil = highpage + 4096 - COMPAT_MSGHDR_SIZE; printf("Evil address is %p\n", evil); if (syscall(__NR_sendmmsg, s, evil, 1, MSG_CMSG_COMPAT) < 0) err(1, "sendmmsg"); return 0; } Signed-off-by: Andy Lutomirski Cc: David S. Miller Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

libceph: wrap auth methods in a mutex

2013-06-20T19:01:32Z

commit e9966076cdd952e19f2dd4854cd719be0d7cbebc upstream. The auth code is called from a variety of contexts, include the mon_client (protected by the monc's mutex) and the messenger callbacks (currently protected by nothing). Avoid chaos by protecting all auth state with a mutex. Nothing is blocking, so this should be simple and lightweight. Signed-off-by: Sage Weil Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman

libceph: wrap auth ops in wrapper functions

2013-06-20T19:01:32Z

commit 27859f9773e4a0b2042435b13400ee2c891a61f4 upstream. Use wrapper functions that check whether the auth op exists so that callers do not need a bunch of conditional checks. Simplifies the external interface. Signed-off-by: Sage Weil Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman

libceph: add update_authorizer auth method

2013-06-20T19:01:32Z

commit 0bed9b5c523d577378b6f83eab5835fe30c27208 upstream. Currently the messenger calls out to a get_authorizer con op, which will create a new authorizer if it doesn't yet have one. In the meantime, when we rotate our service keys, the authorizer doesn't get updated. Eventually it will be rejected by the server on a new connection attempt and get invalidated, and we will then rebuild a new authorizer, but this is not ideal. Instead, if we do have an authorizer, call a new update_authorizer op that will verify that the current authorizer is using the latest secret. If it is not, we will build a new one that does. This avoids the transient failure. This fixes one of the sorry sequence of events for bug http://tracker.ceph.com/issues/4282 Signed-off-by: Sage Weil Reviewed-by: Alex Elder Signed-off-by: Greg Kroah-Hartman