- Oct 01, 2012
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Al Viro authored
same situation as with alpha and arm - only massage needed Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
... and don't bother with syscall return path in case of kernel threads. Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
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>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
get rid of sys_execve() wrapper, while we are at it Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
... 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>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
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>
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Al Viro authored
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>
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Al Viro authored
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>
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Al Viro authored
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>
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- Sep 20, 2012
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Al Viro authored
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>
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Al Viro authored
... rather than duplicating that in sigframe setup code (and doing that inconsistently, at that) Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
... assuming it's needed to be done at all Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
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>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
Signed-off-by:
Al Viro <viro@zeniv.linux.org.uk>
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Al Viro authored
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>
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git://git.kernel.dk/linux-blockLinus Torvalds authored
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
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git://github.com/pmundt/linux-shLinus Torvalds authored
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.
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git://git.kernel.org/pub/scm/linux/kernel/git/ohad/rpmsgLinus Torvalds authored
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
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git://neil.brown.name/mdLinus Torvalds authored
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."
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git://git.kernel.org/pub/scm/linux/kernel/git/tj/wqLinus Torvalds authored
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
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Tejun Heo authored
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: ed48ece2 ("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
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Tejun Heo authored
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
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- Sep 19, 2012
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NeilBrown authored
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>
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NeilBrown authored
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>
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NeilBrown authored
This reverts commit 895e3c5c . 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>
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git://git.kernel.org/pub/scm/linux/kernel/git/ohad/hwspinlockLinus Torvalds authored
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
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Miklos Szeredi authored
IBM reported a soft lockup after applying the fix for the rename_lock deadlock. Commit c83ce989 ("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>
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- Sep 18, 2012
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Stephen M. Cameron authored
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>
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Alan Cox authored
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>
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