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2014-08-08kexec: move segment verification code in a separate functionVivek Goyal1-82/+100
Previously do_kimage_alloc() will allocate a kimage structure, copy segment list from user space and then do the segment list sanity verification. Break down this function in 3 parts. do_kimage_alloc_init() to do actual allocation and basic initialization of kimage structure. copy_user_segment_list() to copy segment list from user space and sanity_check_segment_list() to verify the sanity of segment list as passed by user space. In later patches, I need to only allocate kimage and not copy segment list from user space. So breaking down in smaller functions enables re-use of code at other places. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kexec: rename unusebale_pages to unusable_pagesVivek Goyal1-3/+3
Let's use the more common "unusable". This patch was originally written and posted by Boris. I am including it in this patch series. Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08bin2c: move bin2c in scripts/basicVivek Goyal1-1/+1
This patch series does not do kernel signature verification yet. I plan to post another patch series for that. Now distributions are already signing PE/COFF bzImage with PKCS7 signature I plan to parse and verify those signatures. Primary goal of this patchset is to prepare groundwork so that kernel image can be signed and signatures be verified during kexec load. This should help with two things. - It should allow kexec/kdump on secureboot enabled machines. - In general it can help even without secureboot. By being able to verify kernel image signature in kexec, it should help with avoiding module signing restrictions. Matthew Garret showed how to boot into a custom kernel, modify first kernel's memory and then jump back to old kernel and bypass any policy one wants to. This patch (of 15): Kexec wants to use bin2c and it wants to use it really early in the build process. See arch/x86/purgatory/ code in later patches. So move bin2c in scripts/basic so that it can be built very early and be usable by arch/x86/purgatory/ Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Cc: Borislav Petkov <bp@suse.de> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Yinghai Lu <yinghai@kernel.org> Cc: Eric Biederman <ebiederm@xmission.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Matthew Garrett <mjg59@srcf.ucam.org> Cc: Greg Kroah-Hartman <greg@kroah.com> Cc: Dave Young <dyoung@redhat.com> Cc: WANG Chao <chaowang@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08shm: add memfd_create() syscallDavid Herrmann1-0/+1
memfd_create() is similar to mmap(MAP_ANON), but returns a file-descriptor that you can pass to mmap(). It can support sealing and avoids any connection to user-visible mount-points. Thus, it's not subject to quotas on mounted file-systems, but can be used like malloc()'ed memory, but with a file-descriptor to it. memfd_create() returns the raw shmem file, so calls like ftruncate() can be used to modify the underlying inode. Also calls like fstat() will return proper information and mark the file as regular file. If you want sealing, you can specify MFD_ALLOW_SEALING. Otherwise, sealing is not supported (like on all other regular files). Compared to O_TMPFILE, it does not require a tmpfs mount-point and is not subject to a filesystem size limit. It is still properly accounted to memcg limits, though, and to the same overcommit or no-overcommit accounting as all user memory. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08mm: allow drivers to prevent new writable mappingsDavid Herrmann1-1/+1
This patch (of 6): The i_mmap_writable field counts existing writable mappings of an address_space. To allow drivers to prevent new writable mappings, make this counter signed and prevent new writable mappings if it is negative. This is modelled after i_writecount and DENYWRITE. This will be required by the shmem-sealing infrastructure to prevent any new writable mappings after the WRITE seal has been set. In case there exists a writable mapping, this operation will fail with EBUSY. Note that we rely on the fact that iff you already own a writable mapping, you can increase the counter without using the helpers. This is the same that we do for i_writecount. Signed-off-by: David Herrmann <dh.herrmann@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ryan Lortie <desrt@desrt.ca> Cc: Lennart Poettering <lennart@poettering.net> Cc: Daniel Mack <zonque@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/acct.c: fix coding style warnings and errorsIonut Alexa1-13/+17
Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08shm: make exit_shm work proportional to task activityJack Miller1-0/+6
This is small set of patches our team has had kicking around for a few versions internally that fixes tasks getting hung on shm_exit when there are many threads hammering it at once. Anton wrote a simple test to cause the issue: http://ozlabs.org/~anton/junkcode/bust_shm_exit.c Before applying this patchset, this test code will cause either hanging tracebacks or pthread out of memory errors. After this patchset, it will still produce output like: root@somehost:~# ./bust_shm_exit 1024 160 ... INFO: rcu_sched detected stalls on CPUs/tasks: {} (detected by 116, t=2111 jiffies, g=241, c=240, q=7113) INFO: Stall ended before state dump start ... But the task will continue to run along happily, so we consider this an improvement over hanging, even if it's a bit noisy. This patch (of 3): exit_shm obtains the ipc_ns shm rwsem for write and holds it while it walks every shared memory segment in the namespace. Thus the amount of work is related to the number of shm segments in the namespace not the number of segments that might need to be cleaned. In addition, this occurs after the task has been notified the thread has exited, so the number of tasks waiting for the ns shm rwsem can grow without bound until memory is exausted. Add a list to the task struct of all shmids allocated by this task. Init the list head in copy_process. Use the ns->rwsem for locking. Add segments after id is added, remove before removing from id. On unshare of NEW_IPCNS orphan any ids as if the task had exited, similar to handling of semaphore undo. I chose a define for the init sequence since its a simple list init, otherwise it would require a function call to avoid include loops between the semaphore code and the task struct. Converting the list_del to list_del_init for the unshare cases would remove the exit followed by init, but I left it blow up if not inited. Signed-off-by: Milton Miller <miltonm@bga.com> Signed-off-by: Jack Miller <millerjo@us.ibm.com> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Manfred Spraul <manfred@colorfullife.com> Cc: Anton Blanchard <anton@samba.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08panic: add TAINT_SOFTLOCKUPJosh Hunt2-0/+2
This taint flag will be set if the system has ever entered a softlockup state. Similar to TAINT_WARN it is useful to know whether or not the system has been in a softlockup state when debugging. [akpm@linux-foundation.org: apply the taint before calling panic()] Signed-off-by: Josh Hunt <johunt@akamai.com> Cc: Jason Baron <jbaron@akamai.com> Cc: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/gcov/fs.c: remove unnecessary null test before debugfs_removeFabian Frederick1-2/+1
This fixes checkpatch warning: WARNING: debugfs_remove(NULL) is safe this check is probably not required Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/fork.c: make mm_init_owner staticVladimir Davydov1-7/+7
It's only used in fork.c:mm_init(). Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08fork: copy mm's vm usage counters under mmap_semVladimir Davydov1-0/+5
If a forking process has a thread calling (un)mmap (silly but still), the child process may have some of its mm's vm usage counters (total_vm and friends) screwed up, because currently they are copied from oldmm w/o holding any locks (memcpy in dup_mm). This patch moves the counters initialization to dup_mmap() to be called under oldmm->mmap_sem, which eliminates any possibility of race. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08fork: reset mm->pinned_vmVladimir Davydov1-0/+1
mm->pinned_vm counts pages of mm's address space that were permanently pinned in memory by increasing their reference counter. The counter was introduced by commit bc3e53f682d9 ("mm: distinguish between mlocked and pinned pages"), while before it locked_vm had been used for such pages. Obviously, we should reset the counter on fork if !CLONE_VM, just like we do with locked_vm, but currently we don't. Let's fix it. This patch will fix the contents of /proc/pid/status:VmPin. ib_umem_get[infiniband] and perf_mmap still check pinned_vm against RLIMIT_MEMLOCK. It's left from the times when pinned pages were accounted under locked_vm, but today it looks wrong. It isn't clear how we should deal with it. We still have some drivers accounting pinned pages under mm->locked_vm - this is what commit bc3e53f682d9 was fighting against. It's infiniband/usnic and vfio. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Roland Dreier <roland@kernel.org> Cc: Sean Hefty <sean.hefty@intel.com> Cc: Hal Rosenstock <hal.rosenstock@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08fork/exec: cleanup mm initializationVladimir Davydov1-27/+20
mm initialization on fork/exec is spread all over the place, which makes the code look inconsistent. We have mm_init(), which is supposed to init/nullify mm's internals, but it doesn't init all the fields it should: - on fork ->mmap,mm_rb,vmacache_seqnum,map_count,mm_cpumask,locked_vm are zeroed in dup_mmap(); - on fork ->pmd_huge_pte is zeroed in dup_mm(), immediately before calling mm_init(); - ->cpu_vm_mask_var ptr is initialized by mm_init_cpumask(), which is called before mm_init() on both fork and exec; - ->context is initialized by init_new_context(), which is called after mm_init() on both fork and exec; Let's consolidate all the initializations in mm_init() to make the code look cleaner. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08proc: constify seq_operationsFabian Frederick1-3/+3
proc_uid_seq_operations, proc_gid_seq_operations and proc_projid_seq_operations are only called in proc_id_map_open with seq_open as const struct seq_operations so we can constify the 3 structures and update proc_id_map_open prototype. text data bss dec hex filename 6817 404 1984 9205 23f5 kernel/user_namespace.o-before 6913 308 1984 9205 23f5 kernel/user_namespace.o-after Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/exit.c: fix coding style warnings and errorsIonut Alexa1-23/+26
Fixed coding style warnings and errors. Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/test_kprobes.c: use current logging functionsFabian Frederick1-56/+31
- Add pr_fmt - Coalesce formats - Use current pr_foo() functions instead of printk - Remove unnecessary "failed" display (already in log level). Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com> Cc: "David S. Miller" <davem@davemloft.net> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kernel/kallsyms.c: fix %pB when there's no symbol at the addressNamhyung Kim1-1/+1
__sprint_symbol() should restore original address when kallsyms_lookup() failed to find a symbol. It's reported when dumpstack shows an address in a dynamically allocated trampoline for ftrace. [ 1314.612287] [<ffffffff81700312>] dump_stack+0x45/0x56 [ 1314.612290] [<ffffffff8125f5b0>] ? meminfo_proc_open+0x30/0x30 [ 1314.612293] [<ffffffffa080a494>] kpatch_ftrace_handler+0x14/0xf0 [kpatch] [ 1314.612306] [<ffffffffa00160c4>] 0xffffffffa00160c3 You can see a difference in the hex address - c4 and c3. Fix it. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Reported-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08page-cgroup: get rid of NR_PCG_FLAGSVladimir Davydov1-2/+0
It's not used anywhere today, so let's remove it. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Acked-by: Michal Hocko <mhocko@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08mm: memcontrol: use page lists for uncharge batchingJohannes Weiner1-4/+0
Pages are now uncharged at release time, and all sources of batched uncharges operate on lists of pages. Directly use those lists, and get rid of the per-task batching state. This also batches statistics accounting, in addition to the res counter charges, to reduce IRQ-disabling and re-enabling. Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Hugh Dickins <hughd@google.com> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08mm: memcontrol: rewrite charge APIJohannes Weiner1-7/+8
These patches rework memcg charge lifetime to integrate more naturally with the lifetime of user pages. This drastically simplifies the code and reduces charging and uncharging overhead. The most expensive part of charging and uncharging is the page_cgroup bit spinlock, which is removed entirely after this series. Here are the top-10 profile entries of a stress test that reads a 128G sparse file on a freshly booted box, without even a dedicated cgroup (i.e. executing in the root memcg). Before: 15.36% cat [kernel.kallsyms] [k] copy_user_generic_string 13.31% cat [kernel.kallsyms] [k] memset 11.48% cat [kernel.kallsyms] [k] do_mpage_readpage 4.23% cat [kernel.kallsyms] [k] get_page_from_freelist 2.38% cat [kernel.kallsyms] [k] put_page 2.32% cat [kernel.kallsyms] [k] __mem_cgroup_commit_charge 2.18% kswapd0 [kernel.kallsyms] [k] __mem_cgroup_uncharge_common 1.92% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.86% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.62% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn After: 15.67% cat [kernel.kallsyms] [k] copy_user_generic_string 13.48% cat [kernel.kallsyms] [k] memset 11.42% cat [kernel.kallsyms] [k] do_mpage_readpage 3.98% cat [kernel.kallsyms] [k] get_page_from_freelist 2.46% cat [kernel.kallsyms] [k] put_page 2.13% kswapd0 [kernel.kallsyms] [k] shrink_page_list 1.88% cat [kernel.kallsyms] [k] __radix_tree_lookup 1.67% cat [kernel.kallsyms] [k] __pagevec_lru_add_fn 1.39% kswapd0 [kernel.kallsyms] [k] free_pcppages_bulk 1.30% cat [kernel.kallsyms] [k] kfree As you can see, the memcg footprint has shrunk quite a bit. text data bss dec hex filename 37970 9892 400 48262 bc86 mm/memcontrol.o.old 35239 9892 400 45531 b1db mm/memcontrol.o This patch (of 4): The memcg charge API charges pages before they are rmapped - i.e. have an actual "type" - and so every callsite needs its own set of charge and uncharge functions to know what type is being operated on. Worse, uncharge has to happen from a context that is still type-specific, rather than at the end of the page's lifetime with exclusive access, and so requires a lot of synchronization. Rewrite the charge API to provide a generic set of try_charge(), commit_charge() and cancel_charge() transaction operations, much like what's currently done for swap-in: mem_cgroup_try_charge() attempts to reserve a charge, reclaiming pages from the memcg if necessary. mem_cgroup_commit_charge() commits the page to the charge once it has a valid page->mapping and PageAnon() reliably tells the type. mem_cgroup_cancel_charge() aborts the transaction. This reduces the charge API and enables subsequent patches to drastically simplify uncharging. As pages need to be committed after rmap is established but before they are added to the LRU, page_add_new_anon_rmap() must stop doing LRU additions again. Revive lru_cache_add_active_or_unevictable(). [hughd@google.com: fix shmem_unuse] [hughd@google.com: Add comments on the private use of -EAGAIN] Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.cz> Cc: Tejun Heo <tj@kernel.org> Cc: Vladimir Davydov <vdavydov@parallels.com> Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-08kprobes: Skip kretprobe hit in NMI context to avoid deadlockMasami Hiramatsu1-1/+12
Skip kretprobe hit in NMI context, because if an NMI happens inside the critical section protected by kretprobe_table.lock and another(or same) kretprobe hit, pre_kretprobe_handler tries to lock kretprobe_table.lock again. Normal interrupts have no problem because they are disabled with the lock. Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Acked-by: Ananth N Mavinakayanahalli <ananth@in.ibm.com> Cc: David S. Miller <davem@davemloft.net> Link: http://lkml.kernel.org/r/20140804031016.11433.65539.stgit@kbuild-fedora.novalocal [ Minor edits for clarity. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-08-07kernel/acct.c: fix coding style warnings and errorsIonut Alexa1-12/+16
Signed-off-by: Ionut Alexa <ionut.m.alexa@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07death to mnt_pinnedAl Viro1-5/+19
Rather than playing silly buggers with vfsmount refcounts, just have acct_on() ask fs/namespace.c for internal clone of file->f_path.mnt and replace it with said clone. Then attach the pin to original vfsmount. Voila - the clone will be alive until the file gets closed, making sure that underlying superblock remains active, etc., and we can drop the original vfsmount, so that it's not kept busy. If the file lives until the final mntput of the original vfsmount, we'll notice that there's an fs_pin (one in bsd_acct_struct that holds that file) and mnt_pin_kill() will take it out. Since ->kill() is synchronous, we won't proceed past that point until these files are closed (and private clones of our vfsmount are gone), so we get the same ordering warranties we used to get. mnt_pin()/mnt_unpin()/->mnt_pinned is gone now, and good riddance - it never became usable outside of kernel/acct.c (and racy wrt umount even there). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07take fs_pin stuff to fs/*Al Viro1-95/+32
Add a new field to fs_pin - kill(pin). That's what umount and r/o remount will be calling for all pins attached to vfsmount and superblock resp. Called after bumping the refcount, so it won't go away under us. Dropping the refcount is responsibility of the instance. All generic stuff moved to fs/fs_pin.c; the next step will rip all the knowledge of kernel/acct.c from fs/super.c and fs/namespace.c. After that - death to mnt_pin(); it was intended to be usable as generic mechanism for code that wants to attach objects to vfsmount, so that they would not make the sucker busy and would get killed on umount. Never got it right; it remained acct.c-specific all along. Now it's very close to being killable. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07start carving bsd_acct_struct upAl Viro1-19/+23
pull generic parts into struct fs_pin. Eventually we want those to replace mnt_pin()/mnt_unpin() mess; that stuff will move to fs/*. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: move mnt_pin() upwards.Al Viro1-2/+1
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07make acct_kill() wait for file closing.Al Viro1-3/+17
Do actual closing of file via schedule_work(). And use __fput_sync() there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: get rid of acct_lock for acct->countAl Viro1-33/+52
* make acct->count atomic and acct freeing - rcu-delayed. * instead of grabbing acct_lock around the places where we take a reference, do that under rcu_read_lock() with atomic_long_inc_not_zero(). * have the new acct locked before making ns->bacct point to it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: get rid of acct_listAl Viro1-80/+55
Put these suckers on per-vfsmount and per-superblock lists instead. Note: right now it's still acct_lock for everything, but that's going to change. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: simplify check_free_space()Al Viro1-39/+11
a) file can't be NULL b) file can't be changed under us c) all writes are serialized by acct->lock; no need to mess with spinlock there. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: new lifetime rulesAl Viro1-106/+114
Do not reuse bsd_acct_struct after closing the damn thing. Structure lifetime is controlled by refcount now. We also have a mutex in there, held over closing and writing (the file is O_APPEND, so we are not losing any concurrency). As the result, we do not need to bother with get_file()/fput() on log write anymore. Moreover, do_acct_process() only needs acct itself; file and pidns are picked from it. Killed instances are distinguished by having NULL ->ns. Refcount is protected by acct_lock; anybody taking the mutex needs to grab a reference first. The things will get a lot simpler in the next commits - this is just the minimal chunk switching to the new lifetime rules. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: serialize acct_on()Al Viro1-0/+4
brute-force - on a global mutex that isn't nested into anything. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct() should honour the limits from the very beginningAl Viro1-2/+2
We need to check free space on the first write to freshly opened log. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07split the slow path in acct_process() offAl Viro1-22/+28
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07separate namespace-independent parts of filling acct_tAl Viro1-47/+51
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: switch to __kernel_write()Al Viro1-19/+12
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07acct: encode_comp_t(0) is 0, fortunately...Al Viro1-3/+0
There was an amusing bogosity in ac_rw calculation - it tried to do encode_comp_t(encode_comp_t(0) / 1024). Seeing that comp_t is a 3-bit exponent + 13-bit mantissa... it's a good thing that 0 is represented by all-bits-clear. The history of that one is interesting - it was introduced in 2.1.68pre1, when acct.c had been reworked and moved to separate file. Two months later (2.1.86) somebody has noticed that the sucker won't compile - there was no task_struct::io_usage. At which point the ac_io calculation had changed from encode_comp_t(current->io_usage) to encode_comp_t(0) and the bug in the next line (absolutely real back then, had it ever managed to compile) become a harmless bogosity. Looks like nobody has ever noticed until now. Anyway, let's bury that idiocy now that it got noticed. 17 years is long enough... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-07Merge commit 'ccbf62d8a284cf181ac28c8e8407dd077d90dd4b' into for-nextAl Viro23-469/+708
backmerge to avoid kernel/acct.c conflict
2014-08-06Merge branch 'akpm' (patchbomb from Andrew Morton)Linus Torvalds6-69/+114
Merge incoming from Andrew Morton: - Various misc things. - arch/sh updates. - Part of ocfs2. Review is slow. - Slab updates. - Most of -mm. - printk updates. - lib/ updates. - checkpatch updates. * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (226 commits) checkpatch: update $declaration_macros, add uninitialized_var checkpatch: warn on missing spaces in broken up quoted checkpatch: fix false positives for --strict "space after cast" test checkpatch: fix false positive MISSING_BREAK warnings with --file checkpatch: add test for native c90 types in unusual order checkpatch: add signed generic types checkpatch: add short int to c variable types checkpatch: add for_each tests to indentation and brace tests checkpatch: fix brace style misuses of else and while checkpatch: add --fix option for a couple OPEN_BRACE misuses checkpatch: use the correct indentation for which() checkpatch: add fix_insert_line and fix_delete_line helpers checkpatch: add ability to insert and delete lines to patch/file checkpatch: add an index variable for fixed lines checkpatch: warn on break after goto or return with same tab indentation checkpatch: emit a warning on file add/move/delete checkpatch: add test for commit id formatting style in commit log checkpatch: emit fewer kmalloc_array/kcalloc conversion warnings checkpatch: improve "no space after cast" test checkpatch: allow multiple const * types ...
2014-08-06Merge tag 'pm+acpi-3.17-rc1' of ↵Linus Torvalds7-222/+475
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull ACPI and power management updates from Rafael Wysocki: "Again, ACPICA leads the pack (47 commits), followed by cpufreq (18 commits) and system suspend/hibernation (9 commits). From the new code perspective, the ACPICA update brings ACPI 5.1 to the table, including a new device configuration object called _DSD (Device Specific Data) that will hopefully help us to operate device properties like Device Trees do (at least to some extent) and changes related to supporting ACPI on ARM. Apart from that we have hibernation changes making it use radix trees to store memory bitmaps which should speed up some operations carried out by it quite significantly. We also have some power management changes related to suspend-to-idle (the "freeze" sleep state) support and more preliminary changes needed to support ACPI on ARM (outside of ACPICA). The rest is fixes and cleanups pretty much everywhere. Specifics: - ACPICA update to upstream version 20140724. That includes ACPI 5.1 material (support for the _CCA and _DSD predefined names, changes related to the DMAR and PCCT tables and ARM support among other things) and cleanups related to using ACPICA's header files. A major part of it is related to acpidump and the core code used by that utility. Changes from Bob Moore, David E Box, Lv Zheng, Sascha Wildner, Tomasz Nowicki, Hanjun Guo. - Radix trees for memory bitmaps used by the hibernation core from Joerg Roedel. - Support for waking up the system from suspend-to-idle (also known as the "freeze" sleep state) using ACPI-based PCI wakeup signaling (Rafael J Wysocki). - Fixes for issues related to ACPI button events (Rafael J Wysocki). - New device ID for an ACPI-enumerated device included into the Wildcat Point PCH from Jie Yang. - ACPI video updates related to backlight handling from Hans de Goede and Linus Torvalds. - Preliminary changes needed to support ACPI on ARM from Hanjun Guo and Graeme Gregory. - ACPI PNP core cleanups from Arjun Sreedharan and Zhang Rui. - Cleanups related to ACPI_COMPANION() and ACPI_HANDLE() macros (Rafael J Wysocki). - ACPI-based device hotplug cleanups from Wei Yongjun and Rafael J Wysocki. - Cleanups and improvements related to system suspend from Lan Tianyu, Randy Dunlap and Rafael J Wysocki. - ACPI battery cleanup from Wei Yongjun. - cpufreq core fixes from Viresh Kumar. - Elimination of a deadband effect from the cpufreq ondemand governor and intel_pstate driver cleanups from Stratos Karafotis. - 350MHz CPU support for the powernow-k6 cpufreq driver from Mikulas Patocka. - Fix for the imx6 cpufreq driver from Anson Huang. - cpuidle core and governor cleanups from Daniel Lezcano, Sandeep Tripathy and Mohammad Merajul Islam Molla. - Build fix for the big_little cpuidle driver from Sachin Kamat. - Configuration fix for the Operation Performance Points (OPP) framework from Mark Brown. - APM cleanup from Jean Delvare. - cpupower utility fixes and cleanups from Peter Senna Tschudin, Andrey Utkin, Himangi Saraogi, Rickard Strandqvist, Thomas Renninger" * tag 'pm+acpi-3.17-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (118 commits) ACPI / LPSS: add LPSS device for Wildcat Point PCH ACPI / PNP: Replace faulty is_hex_digit() by isxdigit() ACPICA: Update version to 20140724. ACPICA: ACPI 5.1: Update for PCCT table changes. ACPICA/ARM: ACPI 5.1: Update for GTDT table changes. ACPICA/ARM: ACPI 5.1: Update for MADT changes. ACPICA/ARM: ACPI 5.1: Update for FADT changes. ACPICA: ACPI 5.1: Support for the _CCA predifined name. ACPICA: ACPI 5.1: New notify value for System Affinity Update. ACPICA: ACPI 5.1: Support for the _DSD predefined name. ACPICA: Debug object: Add current value of Timer() to debug line prefix. ACPICA: acpihelp: Add UUID support, restructure some existing files. ACPICA: Utilities: Fix local printf issue. ACPICA: Tables: Update for DMAR table changes. ACPICA: Remove some extraneous printf arguments. ACPICA: Update for comments/formatting. No functional changes. ACPICA: Disassembler: Add support for the ToUUID opererator (macro). ACPICA: Remove a redundant cast to acpi_size for ACPI_OFFSET() macro. ACPICA: Work around an ancient GCC bug. ACPI / processor: Make it possible to get local x2apic id via _MAT ...
2014-08-06Merge tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsiLinus Torvalds1-0/+1
Pull SCSI updates from James Bottomley: "This patch set consists of the usual driver updates (ufs, storvsc, pm8001 hpsa). It also has removal of the user space target driver code (everyone is using LIO now), a partial PCI MSI-X update, more multi-queue updates, conversion to 64 bit LUNs (so we could theoretically cope with any LUN returned by a device) and placeholder support for the ZBC device type (Shingle drives), plus an assortment of minor updates and bug fixes" * tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (143 commits) scsi: do not issue SCSI RSOC command to Promise Vtrak E610f vmw_pvscsi: Use pci_enable_msix_exact() instead of pci_enable_msix() pm8001: Fix invalid return when request_irq() failed lpfc: Remove superfluous call to pci_disable_msix() isci: Use pci_enable_msix_exact() instead of pci_enable_msix() bfa: Use pci_enable_msix_exact() instead of pci_enable_msix() bfa: Cleanup bfad_setup_intr() function bfa: Do not call pci_enable_msix() after it failed once fnic: Use pci_enable_msix_exact() instead of pci_enable_msix() scsi: use short driver name for per-driver cmd slab caches scsi_debug: support scsi-mq, queues and locks Drivers: add blist flags scsi: ufs: fix endianness sparse warnings scsi: ufs: make undeclared functions static bnx2i: Update driver version to 2.7.10.1 pm8001: fix a memory leak in nvmd_resp pm8001: fix update_flash pm8001: fix a memory leak in flash_update pm8001: Cleaning up uninitialized variables pm8001: Fix to remove null pointer checks that could never happen ...
2014-08-06kernel/printk/printk.c: fix bool assignementsNeil Zhang1-3/+3
Fix coccinelle warnings. Signed-off-by: Neil Zhang <zhangwm@marvell.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: enable interrupts before calling console_trylock_for_printk()Jan Kara1-10/+21
We need interrupts disabled when calling console_trylock_for_printk() only so that cpu id we pass to can_use_console() remains valid (for other things console_sem provides all the exclusion we need and deadlocks on console_sem due to interrupts are impossible because we use down_trylock()). However if we are rescheduled, we are guaranteed to run on an online cpu so we can easily just get the cpu id in can_use_console(). We can lose a bit of performance when we enable interrupts in vprintk_emit() and then disable them again in console_unlock() but OTOH it can somewhat reduce interrupt latency caused by console_unlock(). We differ from (reverted) commit 939f04bec1a4 in that we avoid calling console_unlock() from vprintk_emit() with lockdep enabled as that has unveiled quite some bugs leading to system freezes during boot (e.g. https://lkml.org/lkml/2014/5/30/242, https://lkml.org/lkml/2014/6/28/521). Signed-off-by: Jan Kara <jack@suse.cz> Tested-by: Andreas Bombe <aeb@debian.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: miscellaneous cleanupsAlex Elder1-13/+13
Some small cleanups to kernel/printk/printk.c. None of them should cause any change in behavior. - When CONFIG_PRINTK is defined, parenthesize the value of LOG_LINE_MAX. - When CONFIG_PRINTK is *not* defined, there is an extra LOG_LINE_MAX definition; delete it. - Pull an assignment out of a conditional expression in console_setup(). - Use isdigit() in console_setup() rather than open coding it. - In update_console_cmdline(), drop a NUL-termination assignment; the strlcpy() call that precedes it guarantees it's not needed. - Simplify some logic in printk_timed_ratelimit(). Signed-off-by: Alex Elder <elder@linaro.org> Reviewed-by: Petr Mladek <pmladek@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jan Kara <jack@suse.cz> Cc: John Stultz <john.stultz@linaro.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: use a clever macroAlex Elder1-10/+2
Use the IS_ENABLED() macro rather than #ifdef blocks to set certain global values. Signed-off-by: Alex Elder <elder@linaro.org> Acked-by: Borislav Petkov <bp@suse.de> Reviewed-by: Petr Mladek <pmladek@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Cc: John Stultz <john.stultz@linaro.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: fix some commentsAlex Elder1-11/+12
Fix a few comments that don't accurately describe their corresponding code. It also fixes some minor typographical errors. Signed-off-by: Alex Elder <elder@linaro.org> Reviewed-by: Petr Mladek <pmladek@suse.cz> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jan Kara <jack@suse.cz> Cc: John Stultz <john.stultz@linaro.org> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: rename DEFAULT_MESSAGE_LOGLEVELAlex Elder1-1/+1
Commit a8fe19ebfbfd ("kernel/printk: use symbolic defines for console loglevels") makes consistent use of symbolic values for printk() log levels. The naming scheme used is different from the one used for DEFAULT_MESSAGE_LOGLEVEL though. Change that symbol name to be MESSAGE_LOGLEVEL_DEFAULT for consistency. And because the value of that symbol comes from a similarly-named config option, rename CONFIG_DEFAULT_MESSAGE_LOGLEVEL as well. Signed-off-by: Alex Elder <elder@linaro.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Jan Kara <jack@suse.cz> Cc: John Stultz <john.stultz@linaro.org> Cc: Petr Mladek <pmladek@suse.cz> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: tweak do_syslog() to match commentsAlex Elder1-1/+1
In do_syslog() there's a path used by kmsg_poll() and kmsg_read() that only needs to know whether there's any data available to read (and not its size). These callers only check for non-zero return. As a shortcut, do_syslog() returns the difference between what has been logged and what has been "seen." The comments say that the "count of records" should be returned but it's not. Instead it returns (log_next_idx - syslog_idx), which is a difference between buffer offsets--and the result could be negative. The behavior is the same (it'll be zero or not in the same cases), but the count of records is more meaningful and it matches what the comments say. So change the code to return that. Signed-off-by: Alex Elder <elder@linaro.org> Cc: Petr Mladek <pmladek@suse.cz> Cc: Jan Kara <jack@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: John Stultz <john.stultz@linaro.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: allow increasing the ring buffer depending on the number of CPUsLuis R. Rodriguez1-0/+34
The default size of the ring buffer is too small for machines with a large amount of CPUs under heavy load. What ends up happening when debugging is the ring buffer overlaps and chews up old messages making debugging impossible unless the size is passed as a kernel parameter. An idle system upon boot up will on average spew out only about one or two extra lines but where this really matters is on heavy load and that will vary widely depending on the system and environment. There are mechanisms to help increase the kernel ring buffer for tracing through debugfs, and those interfaces even allow growing the kernel ring buffer per CPU. We also have a static value which can be passed upon boot. Relying on debugfs however is not ideal for production, and relying on the value passed upon bootup is can only used *after* an issue has creeped up. Instead of being reactive this adds a proactive measure which lets you scale the amount of contributions you'd expect to the kernel ring buffer under load by each CPU in the worst case scenario. We use num_possible_cpus() to avoid complexities which could be introduced by dynamically changing the ring buffer size at run time, num_possible_cpus() lets us use the upper limit on possible number of CPUs therefore avoiding having to deal with hotplugging CPUs on and off. This introduces the kernel configuration option LOG_CPU_MAX_BUF_SHIFT which is used to specify the maximum amount of contributions to the kernel ring buffer in the worst case before the kernel ring buffer flips over, the size is specified as a power of 2. The total amount of contributions made by each CPU must be greater than half of the default kernel ring buffer size (1 << LOG_BUF_SHIFT bytes) in order to trigger an increase upon bootup. The kernel ring buffer is increased to the next power of two that would fit the required minimum kernel ring buffer size plus the additional CPU contribution. For example if LOG_BUF_SHIFT is 18 (256 KB) you'd require at least 128 KB contributions by other CPUs in order to trigger an increase of the kernel ring buffer. With a LOG_CPU_BUF_SHIFT of 12 (4 KB) you'd require at least anything over > 64 possible CPUs to trigger an increase. If you had 128 possible CPUs the amount of minimum required kernel ring buffer bumps to: ((1 << 18) + ((128 - 1) * (1 << 12))) / 1024 = 764 KB Since we require the ring buffer to be a power of two the new required size would be 1024 KB. This CPU contributions are ignored when the "log_buf_len" kernel parameter is used as it forces the exact size of the ring buffer to an expected power of two value. [pmladek@suse.cz: fix build] Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Signed-off-by: Petr Mladek <pmladek@suse.cz> Tested-by: Davidlohr Bueso <davidlohr@hp.com> Tested-by: Petr Mladek <pmladek@suse.cz> Reviewed-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-08-06printk: make dynamic units clear for the kernel ring bufferLuis R. Rodriguez1-1/+1
Signed-off-by: Luis R. Rodriguez <mcgrof@suse.com> Suggested-by: Davidlohr Bueso <davidlohr@hp.com> Cc: Andrew Lunn <andrew@lunn.ch> Cc: Stephen Warren <swarren@wwwdotorg.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Joe Perches <joe@perches.com> Cc: Arun KS <arunks.linux@gmail.com> Cc: Kees Cook <keescook@chromium.org> Cc: Davidlohr Bueso <davidlohr@hp.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>