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2012-10-01s390: fold execve_tail() into start_thread(), convert to generic sys_execve()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01um: switch to generic kernel_thread()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01x86, um/x86: switch to generic sys_execve and kernel_execveAl Viro
32bit wrapper is lost on that; 64bit one is *not*, since we need to arrange for full pt_regs on stack when we call sys_execve() and we need to load callee-saved ones from there afterwards. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01x86: split ret_from_forkAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01alpha: introduce ret_from_kernel_execve(), switch to generic kernel_execve()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01alpha: switch to generic kernel_thread()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01alpha: switch to generic sys_execve()Al Viro
get rid of sys_execve() wrapper, while we are at it Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01arm: get rid of execve wrapper, switch to generic execve() implementationAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01arm: optimized current_pt_regs()Al Viro
... no need to read current_thread_info()->task only to feed it to task_thread_page() immediately afterwards. Moreover, not using current_thread_info() at all ends up with better assembler - we need a location very close to the top of kernel stack page and it's actually better to do or with 0x1fff, followed be subtracting a small constant than and with ~0x1fff, followed by adding a large one. Both & and | would be a couple of insns (mvn lsr/mvn lsl for |, a pair of bic for &), but the following addition would cost a pair of add while the subtraction ends up as a single sub. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01arm: introduce ret_from_kernel_execve(), switch to generic kernel_execve()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01arm: split ret_from_fork, simplify kernel_thread() [based on patch by rmk]Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-01generic sys_execve()Al Viro
Selected by __ARCH_WANT_SYS_EXECVE in unistd.h. Requires * working current_pt_regs() * *NOT* doing a syscall-in-kernel kind of kernel_execve() implementation. Using generic kernel_execve() is fine. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30generic kernel_execve()Al Viro
based mostly on arm and alpha versions. Architectures can define __ARCH_WANT_KERNEL_EXECVE and use it, provided that * they have working current_pt_regs(), even for kernel threads. * kernel_thread-spawned threads do have space for pt_regs in the normal location. Normally that's as simple as switching to generic kernel_thread() and making sure that kernel threads do *not* go through return from syscall path; call the payload from equivalent of ret_from_fork if we are in a kernel thread (or just have separate ret_from_kernel_thread and make copy_thread() use it instead of ret_from_fork in kernel thread case). * they have ret_from_kernel_execve(); it is called after successful do_execve() done by kernel_execve() and gets normal pt_regs location passed to it as argument. It's essentially a longjmp() analog - it should set sp, etc. to the situation expected at the return for syscall and go there. Eventually the need for that sucker will disappear, but that'll take some surgery on kernel_thread() payloads. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30new helper: current_pt_regs()Al Viro
Normally (and that's the default) it's just task_pt_regs(current). However, if an architecture can optimize that, it can do so by making a macro of its own available from asm/ptrace.h. More importantly, some architectures have task_pt_regs() working only for traced tasks blocked on signal delivery. current_pt_regs() needs to work for *all* processes, so before those architectures start using stuff relying on current_pt_regs() they'll need a properly working variant. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-30preparation for generic kernel_thread()Al Viro
Let architectures select GENERIC_KERNEL_THREAD and have their copy_thread() treat NULL regs as "it came from kernel_thread(), sp argument contains the function new thread will be calling and stack_size - the argument for that function". Switching the architectures begins shortly... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20um: kill thread->forkingAl Viro
we only use that to tell copy_thread() done by syscall from that done by kernel_thread(). However, it's easier to do simply by checking PF_KTHREAD in thread flags. Merge sys_clone() guts for 32bit and 64bit, while we are at it... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20um: let signal_delivered() do SIGTRAP on singlestepping into handlerAl Viro
... rather than duplicating that in sigframe setup code (and doing that inconsistently, at that) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20um: don't leak floating point state and segment registers on execve()Al Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20um: take cleaning singlestep to start_thread()Al Viro
... assuming it's needed to be done at all Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20don't bother exporting kernel_execve()Al Viro
most of the architectures don't and there's not a single caller outside of core kernel. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20the only place that needs to include asm/exec.h is linux/binfmts.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20get rid of generic instances of asm/exec.hAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-20x86: get rid of TIF_IRET hackeryAl Viro
TIF_NOTIFY_RESUME will work in precisely the same way; all that is achieved by TIF_IRET is appearing that there's some work to be done, so we end up on the iret exit path. Just use NOTIFY_RESUME. And for execve() do that in 32bit start_thread(), not sys_execve() itself. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-09-19Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A small collection of driver fixes/updates and a core fix for 3.6. It contains: - Bug fixes for mtip32xx, and support for new hardware (just addition of IDs). They have been queued up for 3.7 for a few weeks as well. - rate-limit a failing command error message in block core. - A fix for an old cciss bug from Stephen. - Prevent overflow of partition count from Alan." * 'for-linus' of git://git.kernel.dk/linux-block: cciss: fix handling of protocol error blk: add an upper sanity check on partition adding mtip32xx: fix user_buffer check in exec_drive_command mtip32xx: Remove dead code mtip32xx: Change printk to pr_xxxx mtip32xx: Proper reporting of write protect status on big-endian mtip32xx: Increase timeout for standby command mtip32xx: Handle NCQ commands during the security locked state mtip32xx: Add support for new devices block: rate-limit the error message from failing commands
2012-09-19Merge tag 'sh-for-linus' of git://github.com/pmundt/linux-shLinus Torvalds
Pull SuperH fixes from Paul Mundt. * tag 'sh-for-linus' of git://github.com/pmundt/linux-sh: sh: Fix up TIF_NOTIFY_RESUME sans TIF_SIGPENDING handling. sh: pfc: Release spinlock in sh_pfc_gpio_request_enable() error path sh: intc: Fix up multi-evt irq association.
2012-09-19Merge tag 'rpmsg-3.6-fix' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsg Pull rpmsg fix from Ohad Ben-Cohen: "A quick rpmsg fix from Fernando, fixing two buggy invocations of dma_free_coherent" * tag 'rpmsg-3.6-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsg: rpmsg: fix dma_free_coherent dev parameter
2012-09-19Merge tag 'md-3.6-fixes' of git://neil.brown.name/mdLinus Torvalds
Pull md fixes from NeilBrown: "3 fixes for md in 3.6. One reverts a recent patch which turns out to not be such a good idea. Other two fix minor bugs with the new (since 3.3) 'replacement' code and have been tagged for -stable." * tag 'md-3.6-fixes' of git://neil.brown.name/md: md: make sure metadata is updated when spares are activated or removed. md/raid5: fix calculate of 'degraded' when a replacement becomes active. Revert "md/raid5: For odirect-write performance, do not set STRIPE_PREREAD_ACTIVE."
2012-09-19Merge branch 'for-3.6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull workqueue / powernow-k8 fix from Tejun Heo: "This is the fix for the bug where cpufreq/powernow-k8 was tripping BUG_ON() in try_to_wake_up_local() by migrating workqueue worker to a different CPU. https://bugzilla.kernel.org/show_bug.cgi?id=47301 As discussed, the fix is now two parts - one to reimplement work_on_cpu() so that it doesn't create a new kthread each time and the actual fix which makes powernow-k8 use work_on_cpu() instead of performing manual migration. While pretty late in the merge cycle, both changes are on the safer side. Jiri and I verified two existing users of work_on_cpu() and Duncan confirmed that the powernow-k8 fix survived about 18 hours of testing." * 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPU workqueue: reimplement work_on_cpu() using system_wq
2012-09-19cpufreq/powernow-k8: workqueue user shouldn't migrate the kworker to another CPUTejun Heo
powernowk8_target() runs off a per-cpu work item and if the cpufreq_policy->cpu is different from the current one, it migrates the kworker to the target CPU by manipulating current->cpus_allowed. The function migrates the kworker back to the original CPU but this is still broken. Workqueue concurrency management requires the kworkers to stay on the same CPU and powernowk8_target() ends up triggerring BUG_ON(rq != this_rq()) in try_to_wake_up_local() if it contends on fidvid_mutex and sleeps. It is unclear why this bug is being reported now. Duncan says it appeared to be a regression of 3.6-rc1 and couldn't reproduce it on 3.5. Bisection seemed to point to 63d95a91 "workqueue: use @pool instead of @gcwq or @cpu where applicable" which is an non-functional change. Given that the reproduce case sometimes took upto days to trigger, it's easy to be misled while bisecting. Maybe something made contention on fidvid_mutex more likely? I don't know. This patch fixes the bug by using work_on_cpu() instead if @pol->cpu isn't the same as the current one. The code assumes that cpufreq_policy->cpu is kept online by the caller, which Rafael tells me is the case. stable: ed48ece27c ("workqueue: reimplement work_on_cpu() using system_wq") should be applied before this; otherwise, the behavior could be horrible. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Duncan <1i5t5.duncan@cox.net> Tested-by: Duncan <1i5t5.duncan@cox.net> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: Andreas Herrmann <andreas.herrmann3@amd.com> Cc: stable@vger.kernel.org Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=47301
2012-09-19workqueue: reimplement work_on_cpu() using system_wqTejun Heo
The existing work_on_cpu() implementation is hugely inefficient. It creates a new kthread, execute that single function and then let the kthread die on each invocation. Now that system_wq can handle concurrent executions, there's no advantage of doing this. Reimplement work_on_cpu() using system_wq which makes it simpler and way more efficient. stable: While this isn't a fix in itself, it's needed to fix a workqueue related bug in cpufreq/powernow-k8. AFAICS, this shouldn't break other existing users. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Jiri Kosina <jkosina@suse.cz> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Bjorn Helgaas <bhelgaas@google.com> Cc: Len Brown <lenb@kernel.org> Cc: Rafael J. Wysocki <rjw@sisk.pl> Cc: stable@vger.kernel.org
2012-09-19md: make sure metadata is updated when spares are activated or removed.NeilBrown
It isn't always necessary to update the metadata when spares are removed as the presence-or-not of a spare isn't really important to the integrity of an array. Also activating a spare doesn't always require updating the metadata as the update on 'recovery-completed' is usually sufficient. However the introduction of 'replacement' devices have made these transitions sometimes more important. For example the 'Replacement' flag isn't cleared until the original device is removed, so we need to ensure a metadata update after that 'spare' is removed. So set MD_CHANGE_DEVS whenever a spare is activated or removed, to complement the current situation where it is set when a spare is added or a device is failed (or a number of other less common situations). This is suitable for -stable as out-of-data metadata could lead to data corruption. This is only relevant for 3.3 and later 9when 'replacement' as introduced. Cc: stable@vger.kernel.org Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19md/raid5: fix calculate of 'degraded' when a replacement becomes active.NeilBrown
When a replacement device becomes active, we mark the device that it replaces as 'faulty' so that it can subsequently get removed. However 'calc_degraded' only pays attention to the primary device, not the replacement, so the array appears to become degraded, which is wrong. So teach 'calc_degraded' to consider any replacement if a primary device is faulty. This is suitable for -stable as an incorrect 'degraded' value can confuse md and could lead to data corruption. This is only relevant for 3.3 and later. Cc: stable@vger.kernel.org Reported-by: Robin Hill <robin@robinhill.me.uk> Reported-by: John Drescher <drescherjm@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-19Revert "md/raid5: For odirect-write performance, do not set ↵NeilBrown
STRIPE_PREREAD_ACTIVE." This reverts commit 895e3c5c58a80bb9e4e05d9ac38b4f30e0f97d80. While this patch seemed like a good idea and did help some workloads, it hurts other workloads. Large sequential O_DIRECT writes were faster, Small random O_DIRECT writes were slower. Other changes (batching RAID5 writes) have improved the sequential writes using a different mechanism, so the net result of this patch is definitely negative. So revert it. Reported-by: Shaohua Li <shli@kernel.org> Tested-by: Jianpeng Ma <majianpeng@gmail.com> Signed-off-by: NeilBrown <neilb@suse.de>
2012-09-18Merge tag 'hwspinlock-3.6-fix' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock Pull hwspinlock fix from Ohad Ben-Cohen: "A single hwspinlock fix by Wei Yongjun, which prevents potential NULL dereferences" * tag 'hwspinlock-3.6-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlock: hwspinlock/core: move the dereference below the NULL test
2012-09-18vfs: dcache: use DCACHE_DENTRY_KILLED instead of DCACHE_DISCONNECTED in d_kill()Miklos Szeredi
IBM reported a soft lockup after applying the fix for the rename_lock deadlock. Commit c83ce989cb5f ("VFS: Fix the nfs sillyrename regression in kernel 2.6.38") was found to be the culprit. The nfs sillyrename fix used DCACHE_DISCONNECTED to indicate that the dentry was killed. This flag can be set on non-killed dentries too, which results in infinite retries when trying to traverse the dentry tree. This patch introduces a separate flag: DCACHE_DENTRY_KILLED, which is only set in d_kill() and makes try_to_ascend() test only this flag. IBM reported successful test results with this patch. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-18cciss: fix handling of protocol errorStephen M. Cameron
If a command completes with a status of CMD_PROTOCOL_ERR, this information should be conveyed to the SCSI mid layer, not dropped on the floor. Unlike a similar bug in the hpsa driver, this bug only affects tape drives and CD and DVD ROM drives in the cciss driver, and to induce it, you have to disconnect (or damage) a cable, so it is not a very likely scenario (which would explain why the bug has gone undetected for the last 10 years.) Signed-off-by: Stephen M. Cameron <scameron@beardog.cce.hp.com> Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-18blk: add an upper sanity check on partition addingAlan Cox
65536 should be ludicrous anyway but without it we overflow the memory computation doing the allocation and badness occurs. Signed-off-by: Alan Cox <alan@linux.intel.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2012-09-18sh: Fix up TIF_NOTIFY_RESUME sans TIF_SIGPENDING handling.Al Viro
As Al notes, we missed a TIF_NOTIFY_RESUME check which caused any handlers without TIF_SIGPENDING also set to skip the notification: Looks like while it is in the relevant masks *and* checked in do_notify_resume() both on 32bit and 64bit variants since commit ab99c733ae73cce31f2a2434f7099564e5a73d95 ("sh: Make syscall tracer use tracehook notifiers, add TIF_NOTIFY_RESUME.") they are actually *not* reached without simulataneous SIGPENDING, since the actual glue in the callers had not been updated back then and still checks for _TIF_SIGPENDING alone when deciding whether to hit do_notify_resume() or not. Reported-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Tested-by: Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-09-18sh: pfc: Release spinlock in sh_pfc_gpio_request_enable() error pathLaurent Pinchart
The sh_pfc_gpio_request_enable() function acquires a spinlock but fails to release it before returning if the requested mux type is not supported. Fix this. Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-09-17Merge branch 'for-3.6-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq Pull another workqueue fix from Tejun Heo: "Unfortunately, yet another late fix. This too is discovered and fixed by Lai. This bug was introduced during this merge window by commit 25511a477657 ("workqueue: reimplement CPU online rebinding to handle idle workers") which started using WORKER_REBIND flag for idle rebind too. The bug is relatively easy to trigger if the CPU rapidly goes through off, on and then off (and stay off). The fix is on the safer side. This hasn't been on linux-next yet but I'm pushing early so that it can get more exposure before v3.6 release." * 'for-3.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq: workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn()
2012-09-17workqueue: always clear WORKER_REBIND in busy_worker_rebind_fn()Lai Jiangshan
busy_worker_rebind_fn() didn't clear WORKER_REBIND if rebinding failed (CPU is down again). This used to be okay because the flag wasn't used for anything else. However, after 25511a477 "workqueue: reimplement CPU online rebinding to handle idle workers", WORKER_REBIND is also used to command idle workers to rebind. If not cleared, the worker may confuse the next CPU_UP cycle by having REBIND spuriously set or oops / get stuck by prematurely calling idle_worker_rebind(). WARNING: at /work/os/wq/kernel/workqueue.c:1323 worker_thread+0x4cd/0x5 00() Hardware name: Bochs Modules linked in: test_wq(O-) Pid: 33, comm: kworker/1:1 Tainted: G O 3.6.0-rc1-work+ #3 Call Trace: [<ffffffff8109039f>] warn_slowpath_common+0x7f/0xc0 [<ffffffff810903fa>] warn_slowpath_null+0x1a/0x20 [<ffffffff810b3f1d>] worker_thread+0x4cd/0x500 [<ffffffff810bc16e>] kthread+0xbe/0xd0 [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10 ---[ end trace e977cf20f4661968 ]--- BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff810b3db0>] worker_thread+0x360/0x500 PGD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC Modules linked in: test_wq(O-) CPU 0 Pid: 33, comm: kworker/1:1 Tainted: G W O 3.6.0-rc1-work+ #3 Bochs Bochs RIP: 0010:[<ffffffff810b3db0>] [<ffffffff810b3db0>] worker_thread+0x360/0x500 RSP: 0018:ffff88001e1c9de0 EFLAGS: 00010086 RAX: 0000000000000000 RBX: ffff88001e633e00 RCX: 0000000000004140 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000009 RBP: ffff88001e1c9ea0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000002 R11: 0000000000000000 R12: ffff88001fc8d580 R13: ffff88001fc8d590 R14: ffff88001e633e20 R15: ffff88001e1c6900 FS: 0000000000000000(0000) GS:ffff88001fc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 0000000000000000 CR3: 00000000130e8000 CR4: 00000000000006f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process kworker/1:1 (pid: 33, threadinfo ffff88001e1c8000, task ffff88001e1c6900) Stack: ffff880000000000 ffff88001e1c9e40 0000000000000001 ffff88001e1c8010 ffff88001e519c78 ffff88001e1c9e58 ffff88001e1c6900 ffff88001e1c6900 ffff88001e1c6900 ffff88001e1c6900 ffff88001fc8d340 ffff88001fc8d340 Call Trace: [<ffffffff810bc16e>] kthread+0xbe/0xd0 [<ffffffff81bd2664>] kernel_thread_helper+0x4/0x10 Code: b1 00 f6 43 48 02 0f 85 91 01 00 00 48 8b 43 38 48 89 df 48 8b 00 48 89 45 90 e8 ac f0 ff ff 3c 01 0f 85 60 01 00 00 48 8b 53 50 <8b> 02 83 e8 01 85 c0 89 02 0f 84 3b 01 00 00 48 8b 43 38 48 8b RIP [<ffffffff810b3db0>] worker_thread+0x360/0x500 RSP <ffff88001e1c9de0> CR2: 0000000000000000 There was no reason to keep WORKER_REBIND on failure in the first place - WORKER_UNBOUND is guaranteed to be set in such cases preventing incorrectly activating concurrency management. Always clear WORKER_REBIND. tj: Updated comment and description. Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2012-09-17Merge branch 'akpm' (Andrew's patch-bomb)Linus Torvalds
Merge fixes from Andrew Morton: "13 patches. 12 are fixes and one is a little preparatory thing for Andi." * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (13 commits) memory hotplug: fix section info double registration bug mm/page_alloc: fix the page address of higher page's buddy calculation drivers/rtc/rtc-twl.c: ensure all interrupts are disabled during probe compiler.h: add __visible pid-namespace: limit value of ns_last_pid to (0, max_pid) include/net/sock.h: squelch compiler warning in sk_rmem_schedule() slub: consider pfmemalloc_match() in get_partial_node() slab: fix starting index for finding another object slab: do ClearSlabPfmemalloc() for all pages of slab nbd: clear waiting_queue on shutdown MAINTAINERS: fix TXT maintainer list and source repo path mm/ia64: fix a memory block size bug memory hotplug: reset pgdat->kswapd to NULL if creating kernel thread fails
2012-09-17memory hotplug: fix section info double registration bugqiuxishi
There may be a bug when registering section info. For example, on my Itanium platform, the pfn range of node0 includes the other nodes, so other nodes' section info will be double registered, and memmap's page count will equal to 3. node0: start_pfn=0x100, spanned_pfn=0x20fb00, present_pfn=0x7f8a3, => 0x000100-0x20fc00 node1: start_pfn=0x80000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x080000-0x100000 node2: start_pfn=0x100000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x100000-0x180000 node3: start_pfn=0x180000, spanned_pfn=0x80000, present_pfn=0x80000, => 0x180000-0x200000 free_all_bootmem_node() register_page_bootmem_info_node() register_page_bootmem_info_section() When hot remove memory, we can't free the memmap's page because page_count() is 2 after put_page_bootmem(). sparse_remove_one_section() free_section_usemap() free_map_bootmem() put_page_bootmem() [akpm@linux-foundation.org: add code comment] Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Signed-off-by: Jiang Liu <jiang.liu@huawei.com> Acked-by: Mel Gorman <mgorman@suse.de> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17mm/page_alloc: fix the page address of higher page's buddy calculationLi Haifeng
The heuristic method for buddy has been introduced since commit 43506fad21ca ("mm/page_alloc.c: simplify calculation of combined index of adjacent buddy lists"). But the page address of higher page's buddy was wrongly calculated, which will lead page_is_buddy to fail for ever. IOW, the heuristic method would be disabled with the wrong page address of higher page's buddy. Calculating the page address of higher page's buddy should be based higher_page with the offset between index of higher page and index of higher page's buddy. Signed-off-by: Haifeng Li <omycle@gmail.com> Signed-off-by: Gavin Shan <shangw@linux.vnet.ibm.com> Reviewed-by: Michal Hocko <mhocko@suse.cz> Cc: KyongHo Cho <pullip.cho@samsung.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Minchan Kim <minchan.kim@gmail.com> Cc: Johannes Weiner <jweiner@redhat.com> Cc: <stable@vger.kernel.org> [2.6.38+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17drivers/rtc/rtc-twl.c: ensure all interrupts are disabled during probeKevin Hilman
On some platforms, bootloaders are known to do some interesting RTC programming. Without going into the obscurities as to why this may be the case, suffice it to say the the driver should not make any assumptions about the state of the RTC when the driver loads. In particular, the driver probe should be sure that all interrupts are disabled until otherwise programmed. This was discovered when finding bursty I2C traffic every second on Overo platforms. This I2C overhead was keeping the SoC from hitting deep power states. The cause was found to be the RTC firing every second on the I2C-connected TWL PMIC. Special thanks to Felipe Balbi for suggesting to look for a rogue driver as the source of the I2C traffic rather than the I2C driver itself. Special thanks to Steve Sakoman for helping track down the source of the continuous RTC interrups on the Overo boards. Signed-off-by: Kevin Hilman <khilman@ti.com> Cc: Felipe Balbi <balbi@ti.com> Tested-by: Steve Sakoman <steve@sakoman.com> Cc: Alessandro Zummo <a.zummo@towertech.it> Tested-by: Shubhrajyoti Datta <omaplinuxkernel@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17compiler.h: add __visibleAndi Kleen
gcc 4.6+ has support for a externally_visible attribute that prevents the optimizer from optimizing unused symbols away. Add a __visible macro to use it with that compiler version or later. This is used (at least) by the "Link Time Optimization" patchset. Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17pid-namespace: limit value of ns_last_pid to (0, max_pid)Andrew Vagin
The kernel doesn't check the pid for negative values, so if you try to write -2 to /proc/sys/kernel/ns_last_pid, you will get a kernel panic. The crash happens because the next pid is -1, and alloc_pidmap() will try to access to a nonexistent pidmap. map = &pid_ns->pidmap[pid/BITS_PER_PAGE]; Signed-off-by: Andrew Vagin <avagin@openvz.org> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17include/net/sock.h: squelch compiler warning in sk_rmem_schedule()Chuck Lever
This warning: In file included from linux/include/linux/tcp.h:227:0, from linux/include/linux/ipv6.h:221, from linux/include/net/ipv6.h:16, from linux/include/linux/sunrpc/clnt.h:26, from linux/net/sunrpc/stats.c:22: linux/include/net/sock.h: In function `sk_rmem_schedule': linux/nfs-2.6/include/net/sock.h:1339:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] is seen with gcc (GCC) 4.6.3 20120306 (Red Hat 4.6.3-2) using the -Wextra option. Commit c76562b6709f ("netvm: prevent a stream-specific deadlock") accidentally replaced the "size" parameter of sk_rmem_schedule() with an unsigned int. This changes the semantics of the comparison in the return statement. In sk_wmem_schedule we have syntactically the same comparison, but "size" is a signed integer. In addition, __sk_mem_schedule() takes a signed integer for its "size" parameter, so there is an implicit type conversion in sk_rmem_schedule() anyway. Revert the "size" parameter back to a signed integer so that the semantics of the expressions in both sk_[rw]mem_schedule() are exactly the same. Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Joonsoo Kim <js1304@gmail.com> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17slub: consider pfmemalloc_match() in get_partial_node()Joonsoo Kim
get_partial() is currently not checking pfmemalloc_match() meaning that it is possible for pfmemalloc pages to leak to non-pfmemalloc users. This is a problem in the following situation. Assume that there is a request from normal allocation and there are no objects in the per-cpu cache and no node-partial slab. In this case, slab_alloc enters the slow path and new_slab_objects() is called which may return a PFMEMALLOC page. As the current user is not allowed to access PFMEMALLOC page, deactivate_slab() is called ([5091b74a: mm: slub: optimise the SLUB fast path to avoid pfmemalloc checks]) and returns an object from PFMEMALLOC page. Next time, when we get another request from normal allocation, slab_alloc() enters the slow-path and calls new_slab_objects(). In new_slab_objects(), we call get_partial() and get a partial slab which was just deactivated but is a pfmemalloc page. We extract one object from it and re-deactivate. "deactivate -> re-get in get_partial -> re-deactivate" occures repeatedly. As a result, access to PFMEMALLOC page is not properly restricted and it can cause a performance degradation due to frequent deactivation. deactivation frequently. This patch changes get_partial_node() to take pfmemalloc_match() into account and prevents the "deactivate -> re-get in get_partial() scenario. Instead, new_slab() is called. Signed-off-by: Joonsoo Kim <js1304@gmail.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-09-17slab: fix starting index for finding another objectJoonsoo Kim
In array cache, there is a object at index 0, check it. Signed-off-by: Joonsoo Kim <js1304@gmail.com> Signed-off-by: Mel Gorman <mgorman@suse.de> Cc: David Miller <davem@davemloft.net> Cc: Chuck Lever <chuck.lever@oracle.com> Cc: David Rientjes <rientjes@google.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>