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2008-08-01tracehook: fix exit_signal=0 caseRoland McGrath1-3/+3
My commit 2b2a1ff64afbadac842bbc58c5166962cf4f7664 introduced a regression (sorry about that) for the odd case of exit_signal=0 (e.g. clone_flags=0). This is not a normal use, but it's used by a case in the glibc test suite. Dying with exit_signal=0 sends no signal, but it's supposed to wake up a parent's blocked wait*() calls (unlike the delayed_group_leader case). This fixes tracehook_notify_death() and its caller to distinguish a "signal 0" wakeup from the delayed_group_leader case (with no wakeup). Signed-off-by: Roland McGrath <roland@redhat.com> Tested-by: Serge Hallyn <serue@us.ibm.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-08-01Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: locking: fix mutex @key parameter kernel-doc notation
2008-08-01Merge branch 'for_linus' of ↵Linus Torvalds1-25/+69
git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jwessel/linux-2.6-kgdb: kgdb: fix gdb serial thread queries kgdb: fix kgdb_validate_break_address to perform a mem write kgdb: remove the requirement for CONFIG_FRAME_POINTER
2008-08-01[PATCH] Fix the bug of using AUDIT_STATUS_RATE_LIMIT when set fail, no error ↵zhangxiliang1-3/+8
output. When the "status_get->mask" is "AUDIT_STATUS_RATE_LIMIT || AUDIT_STATUS_BACKLOG_LIMIT". If "audit_set_rate_limit" fails and "audit_set_backlog_limit" succeeds, the "err" value will be greater than or equal to 0. It will miss the failure of rate set. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01[PATCH] Fix the kernel panic of audit_filter_task when key field is setzhangxiliang1-1/+1
When calling audit_filter_task(), it calls audit_filter_rules() with audit_context is NULL. If the key field is set, the result in audit_filter_rules() will be set to 1 and ctx->filterkey will be set to key. But the ctx is NULL in this condition, so kernel will panic. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01Re: [PATCH] the loginuid field should be output in all AUDIT_CONFIG_CHANGE ↵zhangxiliang1-2/+8
audit messages > shouldn't these be using the "audit_get_loginuid(current)" and if we > are going to output loginuid we also should be outputting sessionid Thanks for your detailed explanation. I have made a new patch for outputing "loginuid" and "sessionid" by audit_get_loginuid(current) and audit_get_sessionid(current). If there are some deficiencies, please give me your indication. Signed-off-by: Zhang Xiliang <zhangxiliang@cn.fujitsu.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01kernel/audit.c control character detection is off-by-oneVesa-Matti J Kari1-1/+1
Hello, According to my understanding there is an off-by-one bug in the function: audit_string_contains_control() in: kernel/audit.c Patch is included. I do not know from how many places the function is called from, but for example, SELinux Access Vector Cache tries to log untrusted filenames via call path: avc_audit() audit_log_untrustedstring() audit_log_n_untrustedstring() audit_string_contains_control() If audit_string_contains_control() detects control characters, then the string is hex-encoded. But the hex=0x7f dec=127, DEL-character, is not detected. I guess this could have at least some minor security implications, since a user can create a filename with 0x7f in it, causing logged filename to possibly look different when someone reads it on the terminal. Signed-off-by: Vesa-Matti Kari <vmkari@cc.helsinki.fi> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01[PATCH] Audit: Collect signal info when SIGUSR2 is sent to auditdEric Paris1-1/+1
Makes the kernel audit subsystem collect information about the sending process when that process sends SIGUSR2 to the userspace audit daemon. SIGUSR2 is a new interesting signal to auditd telling auditd that it should try to start logging to disk again and the error condition which caused it to stop logging to disk (usually out of space) has been rectified. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-08-01kgdb: fix gdb serial thread queriesJason Wessel1-18/+50
The command "info threads" did not work correctly with kgdb. It would result in a silent kernel hang if used. This patach addresses several problems. - Fix use of deprecated NR_CPUS - Fix kgdb to not walk linearly through the pid space - Correctly implement shadow pids - Change the threads per query to a #define - Fix kgdb_hex2long to work with negated values The threads 0 and -1 are reserved to represent the current task. That means that CPU 0 will start with a shadow thread id of -2, and CPU 1 will have a shadow thread id of -3, etc... From the debugger you can switch to a shadow thread to see what one of the other cpus was doing, however it is not possible to execute run control operations on any other cpu execept the cpu executing the kgdb_handle_exception(). Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2008-08-01kgdb: fix kgdb_validate_break_address to perform a mem writeJason Wessel1-7/+19
A regression to the kgdb core was found in the case of using the CONFIG_DEBUG_RODATA kernel option. When this option is on, a breakpoint cannot be written into any readonly memory page. When an external debugger requests a breakpoint to get set, the kgdb_validate_break_address() was only checking to see if the address to place the breakpoint was readable and lacked a write check. This patch changes the validate routine to try reading (via the breakpoint set request) and also to try immediately writing the break point. If either fails, an error is correctly returned and the debugger behaves correctly. Then an end user can make the descision to use hardware breakpoints. Also update the documentation to reflect that using CONFIG_DEBUG_RODATA will inhibit the use of software breakpoints. Signed-off-by: Jason Wessel <jason.wessel@windriver.com>
2008-07-30sched: make scheduler sysfs attributes sysdev class devicesAndi Kleen1-11/+11
They are really class devices, but were incorrectly declared. This leads to crashes with the recent changes that makes non normal sysdevs use a different prototype. [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Pierre Ossman <drzeus-list@drzeus.cx> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30workqueues: add comments to __create_workqueue_key()Oleg Nesterov1-1/+12
Dmitry Adamushko pointed out that the error handling in __create_workqueue_key() is not clear, add the comment. Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Cc: Dmitry Adamushko <dmitry.adamushko@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30printk: fix comment for printk ratelimitingUwe Kleine-König1-4/+4
The comment assumed the burst to be one and the ratelimit used to be named printk_ratelimit_jiffies. Signed-off-by: Uwe Kleine-König <Uwe.Kleine-Koenig@digi.com> Cc: Dave Young <hidave.darkstar@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30markers: fix markers read barrier for multiple probesMathieu Desnoyers1-2/+10
Paul pointed out two incorrect read barriers in the marker handler code in the path where multiple probes are connected. Those are ordering reads of "ptype" (single or multi probe marker), "multi" array pointer, and "multi" array data access. It should be ordered like this : read ptype smp_rmb() read multi array pointer smp_read_barrier_depends() access data referenced by multi array pointer The code with a single probe connected (optimized case, does not have to allocate an array) has correct memory ordering. It applies to kernel 2.6.26.x, 2.6.25.x and linux-next. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com> Cc: <stable@kernel.org> [2.6.25.x, 2.6.26.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cpuset: clean up cpuset hierarchy traversal codeLi Zefan1-13/+8
Use cpuset.stack_list rather than kfifo, so we avoid memory allocation for kfifo. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cpuset: fix wrong calculation of relax domain levelLi Zefan1-1/+1
When multiple cpusets are overlapping in their 'cpus' and hence they form a single sched domain, the largest sched_relax_domain_level among those should be used. But when top_cpuset's sched_load_balance is set, its sched_relax_domain_level is used regardless other sub-cpusets'. This patch fixes it by walking the cpuset hierarchy to find the largest sched_relax_domain_level. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cpuset: speed up sched domain partitionLai Jiangshan1-4/+37
All child cpusets contain a subset of the parent's cpus, so we can skip them when partitioning sched domains. This decreases 'csa' greately for cpusets with multi-level hierarchy. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Reviewed-by: Paul Jackson <pj@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cpuset: a bit cleanup for scan_for_empty_cpusets()Li Zefan1-5/+2
clean up hierarchy traversal code Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Jackson <pj@sgi.com> Cc: Cliff Wickman <cpw@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cgroup: uninline cgroup_has_css_refs()Li Zefan1-1/+1
It's not small enough, and has 2 call sites. text data bss dec hex filename 12813 1676 4832 19321 4b79 cgroup.o.orig 12775 1676 4832 19283 4b53 cgroup.o Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cgroup: remove duplicate code in allocate_cg_link()Li Zefan1-18/+12
- just call free_cg_links() in allocate_cg_links() - the list will get initialized in allocate_cg_links(), so don't init it twice Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30cgroup: fix possible memory leakLi Zefan1-2/+5
There's a leak if copy_from_user() returns failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Cedric Le Goater <clg@fr.ibm.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-30resource: add resource_size()Magnus Damm1-1/+1
Avoid one-off errors by introducing a resource_size() function. Signed-off-by: Magnus Damm <damm@igel.co.jp> Cc: Ben Dooks <ben-linux@fluff.org> Cc: Jean Delvare <khali@linux-fr.org> Cc: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-28Merge branch 'for-linus' of ↵Linus Torvalds2-0/+155
git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jbarnes/pci-2.6: (21 commits) x86/PCI: use dev_printk when possible PCI: add D3 power state avoidance quirk PCI: fix bogus "'device' may be used uninitialized" warning in pci_slot PCI: add an option to allow ASPM enabled forcibly PCI: disable ASPM on pre-1.1 PCIe devices PCI: disable ASPM per ACPI FADT setting PCI MSI: Don't disable MSIs if the mask bit isn't supported PCI: handle 64-bit resources better on 32-bit machines PCI: rewrite PCI BAR reading code PCI: document pci_target_state PCI hotplug: fix typo in pcie hotplug output x86 gart: replace to_pages macro with iommu_num_pages x86, AMD IOMMU: replace to_pages macro with iommu_num_pages iommu: add iommu_num_pages helper function dma-coherent: add documentation to new interfaces Cris: convert to using generic dma-coherent mem allocator Sh: use generic per-device coherent dma allocator ARM: support generic per-device coherent dma mem Generic dma-coherent: fix DMA_MEMORY_EXCLUSIVE x86: use generic per-device dma coherent allocator ...
2008-07-28mmu-notifiers: coreAndrea Arcangeli1-0/+3
With KVM/GFP/XPMEM there isn't just the primary CPU MMU pointing to pages. There are secondary MMUs (with secondary sptes and secondary tlbs) too. sptes in the kvm case are shadow pagetables, but when I say spte in mmu-notifier context, I mean "secondary pte". In GRU case there's no actual secondary pte and there's only a secondary tlb because the GRU secondary MMU has no knowledge about sptes and every secondary tlb miss event in the MMU always generates a page fault that has to be resolved by the CPU (this is not the case of KVM where the a secondary tlb miss will walk sptes in hardware and it will refill the secondary tlb transparently to software if the corresponding spte is present). The same way zap_page_range has to invalidate the pte before freeing the page, the spte (and secondary tlb) must also be invalidated before any page is freed and reused. Currently we take a page_count pin on every page mapped by sptes, but that means the pages can't be swapped whenever they're mapped by any spte because they're part of the guest working set. Furthermore a spte unmap event can immediately lead to a page to be freed when the pin is released (so requiring the same complex and relatively slow tlb_gather smp safe logic we have in zap_page_range and that can be avoided completely if the spte unmap event doesn't require an unpin of the page previously mapped in the secondary MMU). The mmu notifiers allow kvm/GRU/XPMEM to attach to the tsk->mm and know when the VM is swapping or freeing or doing anything on the primary MMU so that the secondary MMU code can drop sptes before the pages are freed, avoiding all page pinning and allowing 100% reliable swapping of guest physical address space. Furthermore it avoids the code that teardown the mappings of the secondary MMU, to implement a logic like tlb_gather in zap_page_range that would require many IPI to flush other cpu tlbs, for each fixed number of spte unmapped. To make an example: if what happens on the primary MMU is a protection downgrade (from writeable to wrprotect) the secondary MMU mappings will be invalidated, and the next secondary-mmu-page-fault will call get_user_pages and trigger a do_wp_page through get_user_pages if it called get_user_pages with write=1, and it'll re-establishing an updated spte or secondary-tlb-mapping on the copied page. Or it will setup a readonly spte or readonly tlb mapping if it's a guest-read, if it calls get_user_pages with write=0. This is just an example. This allows to map any page pointed by any pte (and in turn visible in the primary CPU MMU), into a secondary MMU (be it a pure tlb like GRU, or an full MMU with both sptes and secondary-tlb like the shadow-pagetable layer with kvm), or a remote DMA in software like XPMEM (hence needing of schedule in XPMEM code to send the invalidate to the remote node, while no need to schedule in kvm/gru as it's an immediate event like invalidating primary-mmu pte). At least for KVM without this patch it's impossible to swap guests reliably. And having this feature and removing the page pin allows several other optimizations that simplify life considerably. Dependencies: 1) mm_take_all_locks() to register the mmu notifier when the whole VM isn't doing anything with "mm". This allows mmu notifier users to keep track if the VM is in the middle of the invalidate_range_begin/end critical section with an atomic counter incraese in range_begin and decreased in range_end. No secondary MMU page fault is allowed to map any spte or secondary tlb reference, while the VM is in the middle of range_begin/end as any page returned by get_user_pages in that critical section could later immediately be freed without any further ->invalidate_page notification (invalidate_range_begin/end works on ranges and ->invalidate_page isn't called immediately before freeing the page). To stop all page freeing and pagetable overwrites the mmap_sem must be taken in write mode and all other anon_vma/i_mmap locks must be taken too. 2) It'd be a waste to add branches in the VM if nobody could possibly run KVM/GRU/XPMEM on the kernel, so mmu notifiers will only enabled if CONFIG_KVM=m/y. In the current kernel kvm won't yet take advantage of mmu notifiers, but this already allows to compile a KVM external module against a kernel with mmu notifiers enabled and from the next pull from kvm.git we'll start using them. And GRU/XPMEM will also be able to continue the development by enabling KVM=m in their config, until they submit all GRU/XPMEM GPLv2 code to the mainline kernel. Then they can also enable MMU_NOTIFIERS in the same way KVM does it (even if KVM=n). This guarantees nobody selects MMU_NOTIFIER=y if KVM and GRU and XPMEM are all =n. The mmu_notifier_register call can fail because mm_take_all_locks may be interrupted by a signal and return -EINTR. Because mmu_notifier_reigster is used when a driver startup, a failure can be gracefully handled. Here an example of the change applied to kvm to register the mmu notifiers. Usually when a driver startups other allocations are required anyway and -ENOMEM failure paths exists already. struct kvm *kvm_arch_create_vm(void) { struct kvm *kvm = kzalloc(sizeof(struct kvm), GFP_KERNEL); + int err; if (!kvm) return ERR_PTR(-ENOMEM); INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); + kvm->arch.mmu_notifier.ops = &kvm_mmu_notifier_ops; + err = mmu_notifier_register(&kvm->arch.mmu_notifier, current->mm); + if (err) { + kfree(kvm); + return ERR_PTR(err); + } + return kvm; } mmu_notifier_unregister returns void and it's reliable. The patch also adds a few needed but missing includes that would prevent kernel to compile after these changes on non-x86 archs (x86 didn't need them by luck). [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: fix mm/filemap_xip.c build] [akpm@linux-foundation.org: fix mm/mmu_notifier.c build] Signed-off-by: Andrea Arcangeli <andrea@qumranet.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Cc: Nick Piggin <npiggin@suse.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Kanoj Sarcar <kanojsarcar@yahoo.com> Cc: Roland Dreier <rdreier@cisco.com> Cc: Steve Wise <swise@opengridcomputing.com> Cc: Avi Kivity <avi@qumranet.com> Cc: Hugh Dickins <hugh@veritas.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Chris Wright <chrisw@redhat.com> Cc: Marcelo Tosatti <marcelo@kvack.org> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: "Paul E. McKenney" <paulmck@us.ibm.com> Cc: Izik Eidus <izike@qumranet.com> Cc: Anthony Liguori <aliguori@us.ibm.com> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-29Merge branch 'linus' into core/generic-dma-coherentIngo Molnar65-1798/+2720
Conflicts: arch/x86/Kconfig Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28Merge branch 'linus' into cpus4096Ingo Molnar5-188/+158
Conflicts: kernel/stop_machine.c Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28cpu masks: optimize and clean up cpumask_of_cpu()Linus Torvalds1-108/+20
Clean up and optimize cpumask_of_cpu(), by sharing all the zero words. Instead of stupidly generating all possible i=0...NR_CPUS 2^i patterns creating a huge array of constant bitmasks, realize that the zero words can be shared. In other words, on a 64-bit architecture, we only ever need 64 of these arrays - with a different bit set in one single world (with enough zero words around it so that we can create any bitmask by just offsetting in that big array). And then we just put enough zeroes around it that we can point every single cpumask to be one of those things. So when we have 4k CPU's, instead of having 4k arrays (of 4k bits each, with one bit set in each array - 2MB memory total), we have exactly 64 arrays instead, each 8k bits in size (64kB total). And then we just point cpumask(n) to the right position (which we can calculate dynamically). Once we have the right arrays, getting "cpumask(n)" ends up being: static inline const cpumask_t *get_cpu_mask(unsigned int cpu) { const unsigned long *p = cpu_bit_bitmap[1 + cpu % BITS_PER_LONG]; p -= cpu / BITS_PER_LONG; return (const cpumask_t *)p; } This brings other advantages and simplifications as well: - we are not wasting memory that is just filled with a single bit in various different places - we don't need all those games to re-create the arrays in some dense format, because they're already going to be dense enough. if we compile a kernel for up to 4k CPU's, "wasting" that 64kB of memory is a non-issue (especially since by doing this "overlapping" trick we probably get better cache behaviour anyway). [ mingo@elte.hu: Converted Linus's mails into a commit. See: http://lkml.org/lkml/2008/7/27/156 http://lkml.org/lkml/2008/7/28/320 Also applied a family filter - which also has the side-effect of leaving out the bits where Linus calls me an idio... Oh, never mind ;-) ] Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Al Viro <viro@ZenIV.linux.org.uk> Cc: Mike Travis <travis@sgi.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28Merge branch 'linus' into cpus4096Ingo Molnar23-283/+617
2008-07-28locking: fix mutex @key parameter kernel-doc notationRandy Dunlap1-0/+1
Fix @key parameter to mutex_init() and one of its callers. Warning(linux-2.6.26-git11//drivers/base/class.c:210): No description found for parameter 'key' Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds5-189/+158
* git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: stop_machine: fix up ftrace.c stop_machine: Wean existing callers off stop_machine_run() stop_machine(): stop_machine_run() changed to use cpu mask Hotplug CPU: don't check cpu_online after take_cpu_down Simplify stop_machine stop_machine: add ALL_CPUS option module: fix build warning with !CONFIG_KALLSYMS
2008-07-28stop_machine: fix up ftrace.cRusty Russell1-3/+3
Simple conversion. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Abhishek Sagar <sagar.abhishek@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Steven Rostedt <rostedt@goodmis.org>
2008-07-28stop_machine: Wean existing callers off stop_machine_run()Rusty Russell2-6/+6
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-28stop_machine(): stop_machine_run() changed to use cpu maskRusty Russell2-15/+15
Instead of a "cpu" arg with magic values NR_CPUS (any cpu) and ~0 (all cpus), pass a cpumask_t. Allow NULL for the common case (where we don't care which CPU the function is run on): temporary cpumask_t's are usually considered bad for stack space. This deprecates stop_machine_run, to be removed soon when all the callers are dead. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-28Hotplug CPU: don't check cpu_online after take_cpu_downRusty Russell1-2/+2
Akinobu points out that if take_cpu_down() succeeds, the cpu must be offline. Remove the cpu_online() check, and put a BUG_ON(). Quoting Akinobu Mita: Actually the cpu_online() check was necessary before appling this stop_machine: simplify patch. With old __stop_machine_run(), __stop_machine_run() could succeed (return !IS_ERR(p) value) even if take_cpu_down() returned non-zero value. The return value of take_cpu_down() was obtained through kthread_stop().. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: "Akinobu Mita" <akinobu.mita@gmail.com>
2008-07-28Simplify stop_machineRusty Russell2-178/+128
stop_machine creates a kthread which creates kernel threads. We can create those threads directly and simplify things a little. Some care must be taken with CPU hotunplug, which has special needs, but that code seems more robust than it was in the past. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
2008-07-28stop_machine: add ALL_CPUS optionJason Baron1-7/+25
-allow stop_mahcine_run() to call a function on all cpus. Calling stop_machine_run() with a 'ALL_CPUS' invokes this new behavior. stop_machine_run() proceeds as normal until the calling cpu has invoked 'fn'. Then, we tell all the other cpus to call 'fn'. Signed-off-by: Jason Baron <jbaron@redhat.com> Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> CC: Adrian Bunk <bunk@stusta.de> CC: Andi Kleen <andi@firstfloor.org> CC: Alexey Dobriyan <adobriyan@gmail.com> CC: Christoph Hellwig <hch@infradead.org> CC: mingo@elte.hu CC: akpm@osdl.org
2008-07-28module: fix build warning with !CONFIG_KALLSYMSWANG Cong1-12/+13
This patch fixed the warning: CC kernel/module.o /home/wangcong/Projects/linux-2.6/kernel/module.c:332: warning: ‘lookup_symbol’ defined but not used Signed-off-by: WANG Cong <wangcong@zeuux.org> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2008-07-27task IO accounting: move all IO statistics in struct task_io_accountingAndrea Righi1-7/+7
Simplify the code of include/linux/task_io_accounting.h. It is also more reasonable to have all the task i/o-related statistics in a single struct (task_io_accounting). Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-27task IO accounting: improve code readabilityAndrea Righi3-47/+12
Put all i/o statistics in struct proc_io_accounting and use inline functions to initialize and increment statistics, removing a lot of single variable assignments. This also reduces the kernel size as following (with CONFIG_TASK_XACCT=y and CONFIG_TASK_IO_ACCOUNTING=y). text data bss dec hex filename 11651 0 0 11651 2d83 kernel/exit.o.before 11619 0 0 11619 2d63 kernel/exit.o.after 10886 132 136 11154 2b92 kernel/fork.o.before 10758 132 136 11026 2b12 kernel/fork.o.after 3082029 807968 4818600 8708597 84e1f5 vmlinux.o.before 3081869 807968 4818600 8708437 84e155 vmlinux.o.after Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Acked-by: Oleg Nesterov <oleg@tv-sign.ru> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-27tracing: remove unused variableAndrea Righi1-1/+0
Remove the following warning with CONFIG_TRACING=y: kernel/trace/trace.c: In function ‘s_next’: kernel/trace/trace.c:1186: warning: unused variable ‘last_ent’ Signed-off-by: Andrea Righi <righi.andrea@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-27lost sysctl fixAl Viro1-7/+9
try_attach() should walk into the matching subdirectory, not the first one... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Valdis.Kletnieks@vt.edu Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26[PATCH] get rid of indirect users of namei.hAl Viro1-0/+1
fs.h needs path.h, not namei.h; nfs_fs.h doesn't need it at all. Several places in the tree needed direct include. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] kill altrootAl Viro3-10/+0
long overdue... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] sanitize ->permission() prototypeAl Viro1-5/+5
* kill nameidata * argument; map the 3 bits in ->flags anybody cares about to new MAY_... ones and pass with the mask. * kill redundant gfs2_iop_permission() * sanitize ecryptfs_permission() * fix remaining places where ->permission() instances might barf on new MAY_... found in mask. The obvious next target in that direction is permission(9) folded fix for nfs_permission() breakage from Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] sanitize proc_sysctlAl Viro1-0/+15
* keep references to ctl_table_head and ctl_table in /proc/sys inodes * grab the former during operations, use the latter for access to entry if that succeeds * have ->d_compare() check if table should be seen for one who does lookup; that allows us to avoid flipping inodes - if we have the same name resolve to different things, we'll just keep several dentries and ->d_compare() will reject the wrong ones. * have ->lookup() and ->readdir() scan the table of our inode first, then walk all ctl_table_header and scan ->attached_by for those that are attached to our directory. * implement ->getattr(). * get rid of insane amounts of tree-walking * get rid of the need to know dentry in ->permission() and of the contortions induced by that. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] sysctl: keep track of tree relationshipsAl Viro1-0/+63
In a sense, that's the heart of the series. It's based on the following property of the trees we are actually asked to add: they can be split into stem that is already covered by registered trees and crown that is entirely new. IOW, if a/b and a/c/d are introduced by our tree, then a/c is also introduced by it. That allows to associate tree and table entry with each node in the union; while directory nodes might be covered by many trees, only one will cover the node by its crown. And that will allow much saner logics for /proc/sys in the next patches. This patch introduces the data structures needed to keep track of that. When adding a sysctl table, we find a "parent" one. Which is to say, find the deepest node on its stem that already is present in one of the tables from our table set or its ancestor sets. That table will be our parent and that node in it - attachment point. Add our table to list anchored in parent, have it refer the parent and contents of attachment point. Also remember where its crown lives. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] allow delayed freeing of ctl_table_headerAl Viro1-1/+36
Refcount the sucker; instead of freeing it by the end of unregistration just drop the refcount and free only when it hits zero. Make sure that we _always_ make ->unregistering non-NULL in start_unregistering(). That allows anybody to get a reference to such puppy, preventing its freeing and reuse. It does *not* block unregistration. Anybody who holds such a reference can * try to grab a "use" reference (ctl_head_grab()); that will succeeds if and only if it hadn't entered unregistration yet. If it succeeds, we can use it in all normal ways until we release the "use" reference (with ctl_head_finish()). Note that this relies on having ->unregistering become non-NULL in all cases when one starts to unregister the sucker. * keep pointers to ctl_table entries; they *can* be freed if the entire thing is unregistered. However, if ctl_head_grab() succeeds, we know that unregistration had not happened (and will not happen until ctl_head_finish()) and such pointers can be used safely. IOW, now we can have inodes under /proc/sys keep references to ctl_table entries, protecting them with references to ctl_table_header and grabbing the latter for the duration of operations that require access to ctl_table. That won't cause deadlocks, since unregistration will not be stopped by mere keeping a reference to ctl_table_header. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26[PATCH] beginning of sysctl cleanup - ctl_table_setAl Viro1-10/+31
New object: set of sysctls [currently - root and per-net-ns]. Contains: pointer to parent set, list of tables and "should I see this set?" method (->is_seen(set)). Current lists of tables are subsumed by that; net-ns contains such a beast. ->lookup() for ctl_table_root returns pointer to ctl_table_set instead of that to ->list of that ctl_table_set. [folded compile fixes by rdd for configs without sysctl] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds3-16/+22
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: ftrace: fix modular build ftrace: disable tracing on acpi idle calls ftrace: remove latency-tracer leftover ftrace: only trace preempt off with preempt tracer ftrace: fix 4d3702b6 (post-v2.6.26): WARNING: at kernel/lockdep.c:2731 check_flags (ftrace)
2008-07-26make cgroup_seqfile_release() staticAdrian Bunk1-1/+1
cgroup_seqfile_release() can become static. Signed-off-by: Adrian Bunk <bunk@kernel.org> Acked-by: Paul Menage <menage@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>