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2011-01-07fs: dcache remove d_mountedNick Piggin4-27/+58
Rather than keep a d_mounted count in the dentry, set a dentry flag instead. The flag can be cleared by checking the hash table to see if there are any mounts left, which is not time critical because it is performed at detach time. The mounted state of a dentry is only used to speculatively take a look in the mount hash table if it is set -- before following the mount, vfsmount lock is taken and mount re-checked without races. This saves 4 bytes on 32-bit, nothing on 64-bit but it does provide a hole I might use later (and some configs have larger than 32-bit spinlocks which might make use of the hole). Autofs4 conversion and changelog by Ian Kent <raven@themaw.net>: In autofs4, when expring direct (or offset) mounts we need to ensure that we block user path walks into the autofs mount, which is covered by another mount. To do this we clear the mounted status so that follows stop before walking into the mount and are essentially blocked until the expire is completed. The automount daemon still finds the correct dentry for the umount due to the follow mount logic in fs/autofs4/root.c:autofs4_follow_link(), which is set as an inode operation for direct and offset mounts only and is called following the lookup that stopped at the covered mount. At the end of the expire the covering mount probably has gone away so the mounted status need not be restored. But we need to check this and only restore the mounted status if the expire failed. XXX: autofs may not work right if we have other mounts go over the top of it? Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: fs_struct use seqlockNick Piggin3-13/+34
Use a seqlock in the fs_struct to enable us to take an atomic copy of the complete cwd and root paths. Use this in the RCU lookup path to avoid a thread-shared spinlock in RCU lookup operations. Multi-threaded apps may now perform path lookups with scalability matching multi-process apps. Operations such as stat(2) become very scalable for multi-threaded workload. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: rcu-walk for path lookupNick Piggin10-340/+1194
Perform common cases of path lookups without any stores or locking in the ancestor dentry elements. This is called rcu-walk, as opposed to the current algorithm which is a refcount based walk, or ref-walk. This results in far fewer atomic operations on every path element, significantly improving path lookup performance. It also avoids cacheline bouncing on common dentries, significantly improving scalability. The overall design is like this: * LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk. * Take the RCU lock for the entire path walk, starting with the acquiring of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are not required for dentry persistence. * synchronize_rcu is called when unregistering a filesystem, so we can access d_ops and i_ops during rcu-walk. * Similarly take the vfsmount lock for the entire path walk. So now mnt refcounts are not required for persistence. Also we are free to perform mount lookups, and to assume dentry mount points and mount roots are stable up and down the path. * Have a per-dentry seqlock to protect the dentry name, parent, and inode, so we can load this tuple atomically, and also check whether any of its members have changed. * Dentry lookups (based on parent, candidate string tuple) recheck the parent sequence after the child is found in case anything changed in the parent during the path walk. * inode is also RCU protected so we can load d_inode and use the inode for limited things. * i_mode, i_uid, i_gid can be tested for exec permissions during path walk. * i_op can be loaded. When we reach the destination dentry, we lock it, recheck lookup sequence, and increment its refcount and mountpoint refcount. RCU and vfsmount locks are dropped. This is termed "dropping rcu-walk". If the dentry refcount does not match, we can not drop rcu-walk gracefully at the current point in the lokup, so instead return -ECHILD (for want of a better errno). This signals the path walking code to re-do the entire lookup with a ref-walk. Aside from the final dentry, there are other situations that may be encounted where we cannot continue rcu-walk. In that case, we drop rcu-walk (ie. take a reference on the last good dentry) and continue with a ref-walk. Again, if we can drop rcu-walk gracefully, we return -ECHILD and do the whole lookup using ref-walk. But it is very important that we can continue with ref-walk for most cases, particularly to avoid the overhead of double lookups, and to gain the scalability advantages on common path elements (like cwd and root). The cases where rcu-walk cannot continue are: * NULL dentry (ie. any uncached path element) * parent with d_inode->i_op->permission or ACLs * dentries with d_revalidate * Following links In future patches, permission checks and d_revalidate become rcu-walk aware. It may be possible eventually to make following links rcu-walk aware. Uncached path elements will always require dropping to ref-walk mode, at the very least because i_mutex needs to be grabbed, and objects allocated. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07kernel: optimise seqlockNick Piggin1-7/+73
Add branch annotations for seqlock read fastpath, and introduce __read_seqcount_begin and __read_seqcount_end functions, that can avoid the smp_rmb() if used carefully. These will be used by store-free path walking algorithm performance is critical and seqlocks are in use. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: avoid inode RCU freeing for pseudo fsNick Piggin5-9/+22
Pseudo filesystems that don't put inode on RCU list or reachable by rcu-walk dentries do not need to RCU free their inodes. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: icache RCU free inodesNick Piggin60-68/+490
RCU free the struct inode. This will allow: - Subsequent store-free path walking patch. The inode must be consulted for permissions when walking, so an RCU inode reference is a must. - sb_inode_list_lock to be moved inside i_lock because sb list walkers who want to take i_lock no longer need to take sb_inode_list_lock to walk the list in the first place. This will simplify and optimize locking. - Could remove some nested trylock loops in dcache code - Could potentially simplify things a bit in VM land. Do not need to take the page lock to follow page->mapping. The downsides of this is the performance cost of using RCU. In a simple creat/unlink microbenchmark, performance drops by about 10% due to inability to reuse cache-hot slab objects. As iterations increase and RCU freeing starts kicking over, this increases to about 20%. In cases where inode lifetimes are longer (ie. many inodes may be allocated during the average life span of a single inode), a lot of this cache reuse is not applicable, so the regression caused by this patch is smaller. The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU, however this adds some complexity to list walking and store-free path walking, so I prefer to implement this at a later date, if it is shown to be a win in real situations. I haven't found a regression in any non-micro benchmark so I doubt it will be a problem. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: consolidate dentry kill sequenceNick Piggin1-74/+61
The tricky locking for disposing of a dentry is duplicated 3 times in the dcache (dput, pruning a dentry from the LRU, and pruning its ancestors). Consolidate them all into a single function dentry_kill. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: use RCU in shrink_dentry_list to reduce lock nestingNick Piggin1-21/+25
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: reduce dcache_inode_lock width in lru scanningNick Piggin1-8/+8
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce prune_one_dentry lockingNick Piggin1-12/+15
prune_one_dentry can avoid quite a bit of locking in the common case where ancestors have an elevated refcount. Alternatively, we could have gone the other way and made fewer trylocks in the case where d_count goes to zero, but is probably less common. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce d_parent lockingNick Piggin1-9/+12
Use RCU to simplify locking in dget_parent. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache rationalise dget variantsNick Piggin12-47/+24
dget_locked was a shortcut to avoid the lazy lru manipulation when we already held dcache_lock (lru manipulation was relatively cheap at that point). However, how that the lru lock is an innermost one, we never hold it at any caller, so the lock cost can now be avoided. We already have well working lazy dcache LRU, so it should be fine to defer LRU manipulations to scan time. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce dcache_inode_lockNick Piggin1-12/+12
dcache_inode_lock can be avoided in d_delete() and d_materialise_unique() in cases where it is not required. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce locking in d_allocNick Piggin1-2/+4
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache reduce dput lockingNick Piggin1-29/+23
It is possible to run dput without taking data structure locks up-front. In many cases where we don't kill the dentry anyway, these locks are not required. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache avoid starvation in dcache multi-step operationsNick Piggin1-14/+42
Long lived dcache "multi-step" operations which retry on rename seq can be starved with a lot of rename activity. If they fail after the 1st pass, take the rename_lock for writing to avoid further starvation. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache remove dcache_lockNick Piggin40-307/+109
dcache_lock no longer protects anything. remove it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: Use rename lock and RCU for multi-step operationsNick Piggin5-30/+152
The remaining usages for dcache_lock is to allow atomic, multi-step read-side operations over the directory tree by excluding modifications to the tree. Also, to walk in the leaf->root direction in the tree where we don't have a natural d_lock ordering. This could be accomplished by taking every d_lock, but this would mean a huge number of locks and actually gets very tricky. Solve this instead by using the rename seqlock for multi-step read-side operations, retry in case of a rename so we don't walk up the wrong parent. Concurrent dentry insertions are not serialised against. Concurrent deletes are tricky when walking up the directory: our parent might have been deleted when dropping locks so also need to check and retry for that. We can also use the rename lock in cases where livelock is a worry (and it is introduced in subsequent patch). Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: increase d_name lock coverageNick Piggin1-2/+12
Cover d_name with d_lock in more cases, where there may be concurrent modification to it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: scale inode alias listNick Piggin9-9/+78
Add a new lock, dcache_inode_lock, to protect the inode's i_dentry list from concurrent modification. d_alias is also protected by d_lock. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache scale subdirsNick Piggin16-160/+339
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't using dcache_lock for these anyway (eg. using i_mutex). Note: if we change the locking rule in future so that ->d_child protection is provided only with ->d_parent->d_lock, it may allow us to reduce some locking. But it would be an exception to an otherwise regular locking scheme, so we'd have to see some good results. Probably not worthwhile. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache scale d_unhashedNick Piggin10-54/+102
Protect d_unhashed(dentry) condition with d_lock. This means keeping DCACHE_UNHASHED bit in synch with hash manipulations. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache scale dentry refcountNick Piggin21-69/+126
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a 0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when we start protecting many other dentry members with d_lock. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache scale lruNick Piggin1-28/+84
Add a new lock, dcache_lru_lock, to protect the dcache LRU list from concurrent modification. d_lru is also protected by d_lock, which allows LRU lists to be accessed without the lru lock, using RCU in future patches. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache scale hashNick Piggin2-44/+64
Add a new lock, dcache_hash_lock, to protect the dcache hash table from concurrent modification. d_hash is also protected by d_lock. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07hostfs: simplify lockingNick Piggin3-17/+24
Remove dcache_lock locking from hostfs filesystem, and move it into dcache helpers. All that is required is a coherent path name. Protection from concurrent modification of the namespace after path name generation is not provided in current code, because dcache_lock is dropped before the path is used. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_hash for rcu-walkNick Piggin25-51/+94
Change d_hash so it may be called from lock-free RCU lookups. See similar patch for d_compare for details. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_compare for rcu-walkNick Piggin23-157/+242
Change d_compare so it may be called from lock-free RCU lookups. This does put significant restrictions on what may be done from the callback, however there don't seem to have been any problems with in-tree fses. If some strange use case pops up that _really_ cannot cope with the rcu-walk rules, we can just add new rcu-unaware callbacks, which would cause name lookup to drop out of rcu-walk mode. For in-tree filesystems, this is just a mechanical change. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: name case update methodNick Piggin4-31/+37
smpfs and ncpfs want to update a live dentry name in-place. Rather than have them open code the locking, provide a documented dcache API. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07jfs: dont overwrite dentry name in d_revalidateNick Piggin1-8/+35
Use vfat's method for dealing with negative dentries to preserve case, rather than overwrite dentry name in d_revalidate, which is a bit ugly and also gets in the way of doing lock-free path walking. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07cifs: dont overwrite dentry name in d_revalidateNick Piggin1-19/+24
Use vfat's method for dealing with negative dentries to preserve case, rather than overwrite dentry name in d_revalidate, which is a bit ugly and also gets in the way of doing lock-free path walking. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: change d_delete semanticsNick Piggin22-42/+47
Change d_delete from a dentry deletion notification to a dentry caching advise, more like ->drop_inode. Require it to be constant and idempotent, and not take d_lock. This is how all existing filesystems use the callback anyway. This makes fine grained dentry locking of dput and dentry lru scanning much simpler. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: dcache documentation cleanupNick Piggin1-12/+6
Remove redundant (and incorrect, since dcache RCU lookup) dentry locking documentation and point to the canonical document. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07config fs: avoid switching ->d_op on live dentryNick Piggin1-8/+9
Switching d_op on a live dentry is racy in general, so avoid it. In this case it is a negative dentry, which is safer, but there are still concurrent ops which may be called on d_op in that case (eg. d_revalidate). So in general a filesystem may not do this. Fix configfs so as not to do this. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07cgroup fs: avoid switching ->d_op on live dentryNick Piggin1-5/+22
Switching d_op on a live dentry is racy in general, so avoid it. In this case it is a negative dentry, which is safer, but there are still concurrent ops which may be called on d_op in that case (eg. d_revalidate). So in general a filesystem may not do this. Fix cgroupfs so as not to do this. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: use fast counters for vfs cachesNick Piggin2-13/+23
percpu_counter library generates quite nasty code, so unless you need to dynamically allocate counters or take fast approximate value, a simple per cpu set of counters is much better. The percpu_counter can never be made to work as well, because it has an indirection from pointer to percpu memory, and it can't use direct this_cpu_inc interfaces because it doesn't use static PER_CPU data, so code will always be worse. In the fastpath, it is the difference between this: incl %gs:nr_dentry # nr_dentry and this: movl percpu_counter_batch(%rip), %edx # percpu_counter_batch, movl $1, %esi #, movq $nr_dentry, %rdi #, call __percpu_counter_add # (plus I clobber registers) __percpu_counter_add: pushq %rbp # movq %rsp, %rbp #, subq $32, %rsp #, movq %rbx, -24(%rbp) #, movq %r12, -16(%rbp) #, movq %r13, -8(%rbp) #, movq %rdi, %rbx # fbc, fbc #APP # 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1 movq %gs:kernel_stack,%rax #, pfo_ret__ # 0 "" 2 #NO_APP incl -8124(%rax) # <variable>.preempt_count movq 32(%rdi), %r12 # <variable>.counters, tcp_ptr__ #APP # 78 "lib/percpu_counter.c" 1 add %gs:this_cpu_off, %r12 # this_cpu_off, tcp_ptr__ # 0 "" 2 #NO_APP movslq (%r12),%r13 #* tcp_ptr__, tmp73 movslq %edx,%rax # batch, batch addq %rsi, %r13 # amount, count cmpq %rax, %r13 # batch, count jge .L27 #, negl %edx # tmp76 movslq %edx,%rdx # tmp76, tmp77 cmpq %rdx, %r13 # tmp77, count jg .L28 #, .L27: movq %rbx, %rdi # fbc, call _raw_spin_lock # addq %r13, 8(%rbx) # count, <variable>.count movq %rbx, %rdi # fbc, movl $0, (%r12) #,* tcp_ptr__ call _raw_spin_unlock # .L29: #APP # 216 "/home/npiggin/usr/src/linux-2.6/arch/x86/include/asm/thread_info.h" 1 movq %gs:kernel_stack,%rax #, pfo_ret__ # 0 "" 2 #NO_APP decl -8124(%rax) # <variable>.preempt_count movq -8136(%rax), %rax #, D.14625 testb $8, %al #, D.14625 jne .L32 #, .L31: movq -24(%rbp), %rbx #, movq -16(%rbp), %r12 #, movq -8(%rbp), %r13 #, leave ret .p2align 4,,10 .p2align 3 .L28: movl %r13d, (%r12) # count,* jmp .L29 # .L32: call preempt_schedule # .p2align 4,,6 jmp .L31 # .size __percpu_counter_add, .-__percpu_counter_add .p2align 4,,15 Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07vfs: revert per-cpu nr_unused counters for dentry and inodesNick Piggin2-21/+12
The nr_unused counters count the number of objects on an LRU, and as such they are synchronized with LRU object insertion and removal and scanning, and protected under the LRU lock. Making it per-cpu does not actually get any concurrency improvements because of this lock, and summing the counter is much slower, and incrementing/decrementing it costs more code size and is slower too. These counters should stay per-LRU, which currently means global. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07kernel: kmem_ptr_validate considered harmfulNick Piggin5-99/+1
This is a nasty and error prone API. It is no longer used, remove it. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07fs: d_validate fixesNick Piggin1-18/+7
d_validate has been broken for a long time. kmem_ptr_validate does not guarantee that a pointer can be dereferenced if it can go away at any time. Even rcu_read_lock doesn't help, because the pointer might be queued in RCU callbacks but not executed yet. So the parent cannot be checked, nor the name hashed. The dentry pointer can not be touched until it can be verified under lock. Hashing simply cannot be used. Instead, verify the parent/child relationship by traversing parent's d_child list. It's slow, but only ncpfs and the destaged smbfs care about it, at this point. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-05Revert "fs: use RCU read side protection in d_validate"Nick Piggin1-12/+19
This reverts commit 3825bdb7ed920845961f32f364454bee5f469abb. You cannot dget() a dentry without having a reference, or holding a lock that guarantees it remains valid. Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-05Linux 2.6.37v2.6.37Linus Torvalds1-1/+1
2011-01-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6Linus Torvalds14-25/+87
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6: ipv4/route.c: respect prefsrc for local routes bridge: stp: ensure mac header is set bridge: fix br_multicast_ipv6_rcv for paged skbs atl1: fix oops when changing tx/rx ring params drivers/atm/atmtcp.c: add missing atm_dev_put starfire: Fix dma_addr_t size test for MIPS tg3: fix return value check in tg3_read_vpd() Broadcom CNIC core network driver: fix mem leak on allocation failures in cnic_alloc_uio_rings() ISDN, Gigaset: Fix memory leak in do_disconnect_req() CAN: Use inode instead of kernel address for /proc file skfp: testing the wrong variable in skfp_driver_init() ppp: allow disabling multilink protocol ID compression ehea: Avoid changing vlan flags ueagle-atm: fix PHY signal initialization race
2011-01-04ipv4/route.c: respect prefsrc for local routesJoel Sing1-2/+6
The preferred source address is currently ignored for local routes, which results in all local connections having a src address that is the same as the local dst address. Fix this by respecting the preferred source address when it is provided for local routes. This bug can be demonstrated as follows: # ifconfig dummy0 192.168.0.1 # ip route show table local | grep local.*dummy0 local 192.168.0.1 dev dummy0 proto kernel scope host src 192.168.0.1 # ip route change table local local 192.168.0.1 dev dummy0 \ proto kernel scope host src 127.0.0.1 # ip route show table local | grep local.*dummy0 local 192.168.0.1 dev dummy0 proto kernel scope host src 127.0.0.1 We now establish a local connection and verify the source IP address selection: # nc -l 192.168.0.1 3128 & # nc 192.168.0.1 3128 & # netstat -ant | grep 192.168.0.1:3128.*EST tcp 0 0 192.168.0.1:3128 192.168.0.1:33228 ESTABLISHED tcp 0 0 192.168.0.1:33228 192.168.0.1:3128 ESTABLISHED Signed-off-by: Joel Sing <jsing@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-04remove trim_fs method from Documentation/filesystems/LockingChristoph Hellwig1-2/+0
The ->trim_fs has been removed meanwhile, so remove it from the documentation as well. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-04Merge master.kernel.org:/home/rmk/linux-2.6-armLinus Torvalds14-157/+78
* master.kernel.org:/home/rmk/linux-2.6-arm: ARM: pxa: fix page table corruption on resume ARM: it8152: add IT8152_LAST_IRQ definition to fix build error ARM: pxa: PXA_ESERIES depends on FB_W100. ARM: 6605/1: Add missing include "asm/memory.h" ARM: 6540/1: Stop irqsoff trace on return to user ARM: 6537/1: update Nomadik, U300 and Ux500 maintainers ARM: 6536/1: Add missing SZ_{32,64,128} ARM: fix cache-feroceon-l2 after stack based kmap_atomic() ARM: fix cache-xsc3l2 after stack based kmap_atomic() ARM: get rid of kmap_high_l1_vipt() ARM: smp: avoid incrementing mm_users on CPU startup ARM: pxa: PXA_ESERIES depends on FB_W100.
2011-01-04arch/mn10300/kernel/irq.c: fix buildAndrew Morton1-1/+1
Addresses https://bugzilla.kernel.org/show_bug.cgi?id=25702 Reported-by: Martin Ettl <ettl.martin@gmx.de> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-04ima: fix add LSM rule bugMimi Zohar1-0/+2
If security_filter_rule_init() doesn't return a rule, then not everything is as fine as the return code implies. This bug only occurs when the LSM (eg. SELinux) is disabled at runtime. Adding an empty LSM rule causes ima_match_rules() to always succeed, ignoring any remaining rules. default IMA TCB policy: # PROC_SUPER_MAGIC dont_measure fsmagic=0x9fa0 # SYSFS_MAGIC dont_measure fsmagic=0x62656572 # DEBUGFS_MAGIC dont_measure fsmagic=0x64626720 # TMPFS_MAGIC dont_measure fsmagic=0x01021994 # SECURITYFS_MAGIC dont_measure fsmagic=0x73636673 < LSM specific rule > dont_measure obj_type=var_log_t measure func=BPRM_CHECK measure func=FILE_MMAP mask=MAY_EXEC measure func=FILE_CHECK mask=MAY_READ uid=0 Thus without the patch, with the boot parameters 'tcb selinux=0', adding the above 'dont_measure obj_type=var_log_t' rule to the default IMA TCB measurement policy, would result in nothing being measured. The patch prevents the default TCB policy from being replaced. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Cc: James Morris <jmorris@namei.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Cc: David Safford <safford@watson.ibm.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-04Merge branch 'fix' of ↵Russell King259-1598/+2484
git://git.kernel.org/pub/scm/linux/kernel/git/ycmiao/pxa-linux-2.6
2011-01-03bridge: stp: ensure mac header is setFlorian Westphal1-0/+2
commit bf9ae5386bca8836c16e69ab8fdbe46767d7452a (llc: use dev_hard_header) removed the skb_reset_mac_header call from llc_mac_hdr_init. This seems fine itself, but br_send_bpdu() invokes ebtables LOCAL_OUT. We oops in ebt_basic_match() because it assumes eth_hdr(skb) returns a meaningful result. Cc: acme@ghostprotocols.net References: https://bugzilla.kernel.org/show_bug.cgi?id=24532 Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-03Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds4-11/+20
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Fix callchain hit bad cast on ascii display arch/x86/oprofile/op_model_amd.c: Perform initialisation on a single CPU watchdog: Improve initialisation error message and documentation