- 21 Oct, 2012 2 commits
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J. Bruce Fields authored
commit cf9182e9 upstream. Processes that open and close multiple files may end up setting this oo_last_closed_stid without freeing what was previously pointed to. This can result in a major leak, visible for example by watching the nfsd4_stateids line of /proc/slabinfo. Reported-by:
Cyril B. <cbay@excellency.fr> Tested-by:
J. Bruce Fields <bfields@redhat.com> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Russell King authored
commit 846a1368 upstream. Michael Olbrich reported that his test program fails when built with -O2 -mcpu=cortex-a8 -mfpu=neon, and a kernel which supports v6 and v7 CPUs: volatile int x = 2; volatile int64_t y = 2; int main() { volatile int a = 0; volatile int64_t b = 0; while (1) { a = (a + x) % (1 << 30); b = (b + y) % (1 << 30); assert(a == b); } } and two instances are run. When built for just v7 CPUs, this program works fine. It uses the "vadd.i64 d19, d18, d16" VFP instruction. It appears that we do not save the high-16 double VFP registers across context switches when the kernel is built for v6 CPUs. Fix that. Tested-By:
Michael Olbrich <m.olbrich@pengutronix.de> Signed-off-by:
Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by:
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- 12 Oct, 2012 38 commits
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Greg Kroah-Hartman authored
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Mike Galbraith authored
commit 8f618968 upstream. Make stop scheduler class do the same accounting as other classes, Migration threads can be caught in the act while doing exec balancing, leading to the below due to use of unmaintained ->se.exec_start. The load that triggered this particular instance was an apparently out of control heavily threaded application that does system monitoring in what equated to an exec bomb, with one of the VERY frequently migrated tasks being ps. %CPU PID USER CMD 99.3 45 root [migration/10] 97.7 53 root [migration/12] 97.0 57 root [migration/13] 90.1 49 root [migration/11] 89.6 65 root [migration/15] 88.7 17 root [migration/3] 80.4 37 root [migration/8] 78.1 41 root [migration/9] 44.2 13 root [migration/2] Signed-off-by:
Mike Galbraith <mgalbraith@suse.de> Signed-off-by:
Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1344051854.6739.19.camel@marge.simpson.netSigned-off-by:
Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by:
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Nikola Pajkovsky authored
commit 68766a2e upstream. In case we detect a problem and bail out, we fail to set "ret" to a nonzero value, and udf_load_logicalvol will mistakenly report success. Signed-off-by:
Nikola Pajkovsky <npajkovs@redhat.com> Signed-off-by:
Jan Kara <jack@suse.cz> Cc: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> Signed-off-by:
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Frediano Ziglio authored
commit fd3ba42c upstream. wchar_t is currently 16bit so converting a utf8 encoded characters not in plane 0 (>= 0x10000) to wchar_t (that is calling char2uni) lead to a -EINVAL return. This patch detect utf8 in cifs_strtoUTF16 and add special code calling utf8s_to_utf16s. Signed-off-by:
Frediano Ziglio <frediano.ziglio@citrix.com> Acked-by:
Jeff Layton <jlayton@redhat.com> Signed-off-by:
Steve French <smfrench@gmail.com> Signed-off-by:
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Jeff Layton authored
commit 72bd481f upstream. Apparently this was lost when we converted to the standard option parser in 8830d7e0Reported-by:
Gregory Lee Bartholomew <gregory.lee.bartholomew@gmail.com> Cc: Sachin Prabhu <sprabhu@redhat.com> Signed-off-by:
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Brian Norris authored
commit 74d83bea upstream. JFFS2 was designed without thought for OOB bitflips, it seems, but they can occur and will be reported to JFFS2 via mtd_read_oob()[1]. We don't want to fail on these transactions, since the data was corrected. [1] Few drivers report bitflips for OOB-only transactions. With such drivers, this patch should have no effect. Signed-off-by:
Brian Norris <computersforpeace@gmail.com> Signed-off-by:
Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by:
David Woodhouse <David.Woodhouse@intel.com> Signed-off-by:
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Guennadi Liakhovetski authored
commit 8464dd52 upstream. On some systems, e.g., kzm9g, MMCIF interfaces can produce spurious interrupts without any active request. To prevent the Oops, that results in such cases, don't dereference the mmc request pointer until we make sure, that we are indeed processing such a request. Reported-by:
Tetsuyuki Kobayashi <koba@kmckk.co.jp> Signed-off-by:
Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by:
Chris Ball <cjb@laptop.org> Signed-off-by:
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Vaibhav Bedia authored
commit c4c8eeb4 upstream. In some cases mmc_suspend_host() is not able to claim the host and proceed with the suspend process. The core returns -EBUSY to the host controller driver. Unfortunately, the host controller driver does not pass on this information to the PM core and hence the system suspend process continues. ret = mmc_suspend_host(host->mmc); if (ret) { host->suspended = 0; if (host->pdata->resume) { ret = host->pdata->resume(dev, host->slot_id); The return status from mmc_suspend_host() is overwritten by return status from host->pdata->resume. So the original return status is lost. In these cases the MMC core gets to an unexpected state during resume and multiple issues related to MMC crop up. 1. Host controller driver starts accessing the device registers before the clocks are enabled which leads to a prefetch abort. 2. A file copy thread which was launched before suspend gets stuck due to the host not being reclaimed during resume. To avoid such problems pass on the -EBUSY status to the PM core from the host controller driver. With this change, MMC core suspend might still fail but it does not end up making the system unusable. Suspend gets aborted and the user can try suspending the system again. Signed-off-by:
Vaibhav Bedia <vaibhav.bedia@ti.com> Signed-off-by:
Hebbar, Gururaja <gururaja.hebbar@ti.com> Acked-by:
Venkatraman S <svenkatr@ti.com> Signed-off-by:
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Andreas Bießmann authored
commit 4d3d688d upstream. Unloading the omap2 nand driver missed to release the memory region which will result in not being able to request it again if one want to load the driver later on. This patch fixes following error when loading omap2 module after unloading: ---8<--- ~ $ rmmod omap2 ~ $ modprobe omap2 [ 37.420928] omap2-nand: probe of omap2-nand.0 failed with error -16 ~ $ --->8--- This error was introduced in 67ce04bf which was the first commit of this driver. Signed-off-by:
Andreas Bießmann <andreas@biessmann.de> Signed-off-by:
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Andreas Bießmann authored
commit 7d9b1102 upstream. Do not kfree() the mtd_info; it is handled in the mtd subsystem and already freed by nand_release(). Instead kfree() the struct omap_nand_info allocated in omap_nand_probe which was not freed before. This patch fixes following error when unloading the omap2 module: ---8<--- ~ $ rmmod omap2 ------------[ cut here ]------------ kernel BUG at mm/slab.c:3126! Internal error: Oops - BUG: 0 [#1] PREEMPT ARM Modules linked in: omap2(-) CPU: 0 Not tainted (3.6.0-rc3-00230-g155e36d4-dirty #3) PC is at cache_free_debugcheck+0x2d4/0x36c LR is at kfree+0xc8/0x2ac pc : [<c01125a0>] lr : [<c0112efc>] psr: 200d0193 sp : c521fe08 ip : c0e8ef90 fp : c521fe5c r10: bf0001fc r9 : c521e000 r8 : c0d99c8c r7 : c661ebc0 r6 : c065d5a4 r5 : c65c4060 r4 : c78005c0 r3 : 00000000 r2 : 00001000 r1 : c65c4000 r0 : 00000001 Flags: nzCv IRQs off FIQs on Mode SVC_32 ISA ARM Segment user Control: 10c5387d Table: 86694019 DAC: 00000015 Process rmmod (pid: 549, stack limit = 0xc521e2f0) Stack: (0xc521fe08 to 0xc5220000) fe00: c008a874 c00bf44c c515c6d0 200d0193 c65c4860 c515c240 fe20: c521fe3c c521fe30 c008a9c0 c008a854 c521fe5c c65c4860 c78005c0 bf0001fc fe40: c780ff40 a00d0113 c521e000 00000000 c521fe84 c521fe60 c0112efc c01122d8 fe60: c65c4860 c0673778 c06737ac 00000000 00070013 00000000 c521fe9c c521fe88 fe80: bf0001fc c0112e40 c0673778 bf001ca8 c521feac c521fea0 c02ca11c bf0001ac fea0: c521fec4 c521feb0 c02c82c4 c02ca100 c0673778 bf001ca8 c521fee4 c521fec8 fec0: c02c8dd8 c02c8250 00000000 bf001ca8 bf001ca8 c0804ee0 c521ff04 c521fee8 fee0: c02c804c c02c8d20 bf001924 00000000 bf001ca8 c521e000 c521ff1c c521ff08 ff00: c02c950c c02c7fbc bf001d48 00000000 c521ff2c c521ff20 c02ca3a4 c02c94b8 ff20: c521ff3c c521ff30 bf001938 c02ca394 c521ffa4 c521ff40 c009beb4 bf001930 ff40: c521ff6c 70616d6f b6fe0032 c0014f84 70616d6f b6fe0032 00000081 60070010 ff60: c521ff84 c521ff70 c008e1f4 c00bf328 0001a004 70616d6f c521ff94 0021ff88 ff80: c008e368 0001a004 70616d6f b6fe0032 00000081 c0015028 00000000 c521ffa8 ffa0: c0014dc0 c009bcd0 0001a004 70616d6f bec2ab38 00000880 bec2ab38 00000880 ffc0: 0001a004 70616d6f b6fe0032 00000081 00000319 00000000 b6fe1000 00000000 ffe0: bec2ab30 bec2ab20 00019f00 b6f539c0 60070010 bec2ab38 aaaaaaaa aaaaaaaa Backtrace: [<c01122cc>] (cache_free_debugcheck+0x0/0x36c) from [<c0112efc>] (kfree+0xc8/0x2ac) [<c0112e34>] (kfree+0x0/0x2ac) from [<bf0001fc>] (omap_nand_remove+0x5c/0x64 [omap2]) [<bf0001a0>] (omap_nand_remove+0x0/0x64 [omap2]) from [<c02ca11c>] (platform_drv_remove+0x28/0x2c) r5:bf001ca8 r4:c0673778 [<c02ca0f4>] (platform_drv_remove+0x0/0x2c) from [<c02c82c4>] (__device_release_driver+0x80/0xdc) [<c02c8244>] (__device_release_driver+0x0/0xdc) from [<c02c8dd8>] (driver_detach+0xc4/0xc8) r5:bf001ca8 r4:c0673778 [<c02c8d14>] (driver_detach+0x0/0xc8) from [<c02c804c>] (bus_remove_driver+0x9c/0x104) r6:c0804ee0 r5:bf001ca8 r4:bf001ca8 r3:00000000 [<c02c7fb0>] (bus_remove_driver+0x0/0x104) from [<c02c950c>] (driver_unregister+0x60/0x80) r6:c521e000 r5:bf001ca8 r4:00000000 r3:bf001924 [<c02c94ac>] (driver_unregister+0x0/0x80) from [<c02ca3a4>] (platform_driver_unregister+0x1c/0x20) r5:00000000 r4:bf001d48 [<c02ca388>] (platform_driver_unregister+0x0/0x20) from [<bf001938>] (omap_nand_driver_exit+0x14/0x1c [omap2]) [<bf001924>] (omap_nand_driver_exit+0x0/0x1c [omap2]) from [<c009beb4>] (sys_delete_module+0x1f0/0x2ec) [<c009bcc4>] (sys_delete_module+0x0/0x2ec) from [<c0014dc0>] (ret_fast_syscall+0x0/0x48) r8:c0015028 r7:00000081 r6:b6fe0032 r5:70616d6f r4:0001a004 Code: e1a00005 eb0d9172 e7f001f2 e7f001f2 (e7f001f2) ---[ end trace 6a30b24d8c0cc2ee ]--- Segmentation fault --->8--- This error was introduced in 67ce04bf which was the first commit of this driver. Signed-off-by:
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Shmulik Ladkani authored
commit 7bb9c754 upstream. The code responsible for reading the version of the mirror bbt was incorrectly using the descriptor of the main bbt. Pass the mirror bbt descriptor to 'scan_read_raw' when reading the version of the mirror bbt. Signed-off-by:
Shmulik Ladkani <shmulik.ladkani@gmail.com> Acked-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by:
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Richard Genoud authored
commit bb0a13a1 upstream. If override size is too big, the module was actually loaded instead of failing, because retval was not set. This lead to memory corruption with the use of the freed structs nandsim and nand_chip. Signed-off-by:
Richard Genoud <richard.genoud@gmail.com> Signed-off-by:
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Alexander Shiyan authored
commit d1f55c68 upstream. Update driver autcpu12-nvram.c so it compiles; map_read32/map_write32 no longer exist in the kernel so the driver is totally broken. Additionally, map_info name passed to simple_map_init is incorrect. Signed-off-by:
Alexander Shiyan <shc_work@mail.ru> Acked-by:
Arnd Bergmann <arnd@arndb.de> Signed-off-by:
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Huang Shijie authored
commit c51803dd upstream. We may cause a memory leak when the @types has more then one parser. Take the `default_mtd_part_types` for example. The default_mtd_part_types has two parsers now: `cmdlinepart` and `ofpart`. Assume the following case: The kernel command line sets the partitions like: #gpmi-nand:20m(boot),20m(kernel),1g(rootfs),-(user) But the devicetree file(such as arch/arm/boot/dts/imx28-evk.dts) also sets the same partitions as the kernel command line does. In the current code, the partitions parsed out by the `ofpart` will overwrite the @pparts which has already set by the `cmdlinepart` parser, and the the partitions parsed out by the `cmdlinepart` is missed. A memory leak occurs. So we should break the code as soon as we parse out the partitions, In actually, this patch makes a priority order between the parsers. If one parser has already parsed out the partitions successfully, it's no need to use another parser anymore. Signed-off-by:
Huang Shijie <shijie8@gmail.com> Signed-off-by:
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Srivatsa S. Bhat authored
commit d35be8ba upstream. In the event of CPU hotplug, the kernel modifies the cpusets' cpus_allowed masks as and when necessary to ensure that the tasks belonging to the cpusets have some place (online CPUs) to run on. And regular CPU hotplug is destructive in the sense that the kernel doesn't remember the original cpuset configurations set by the user, across hotplug operations. However, suspend/resume (which uses CPU hotplug) is a special case in which the kernel has the responsibility to restore the system (during resume), to exactly the same state it was in before suspend. In order to achieve that, do the following: 1. Don't modify cpusets during suspend/resume. At all. In particular, don't move the tasks from one cpuset to another, and don't modify any cpuset's cpus_allowed mask. So, simply ignore cpusets during the CPU hotplug operations that are carried out in the suspend/resume path. 2. However, cpusets and sched domains are related. We just want to avoid altering cpusets alone. So, to keep the sched domains updated, build a single sched domain (containing all active cpus) during each of the CPU hotplug operations carried out in s/r path, effectively ignoring the cpusets' cpus_allowed masks. (Since userspace is frozen while doing all this, it will go unnoticed.) 3. During the last CPU online operation during resume, build the sched domains by looking up the (unaltered) cpusets' cpus_allowed masks. That will bring back the system to the same original state as it was in before suspend. Ultimately, this will not only solve the cpuset problem related to suspend resume (ie., restores the cpusets to exactly what it was before suspend, by not touching it at all) but also speeds up suspend/resume because we avoid running cpuset update code for every CPU being offlined/onlined. Signed-off-by:
Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by:
Ingo Molnar <mingo@kernel.org> Signed-off-by:
Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by:
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Seiji Aguchi authored
commit d6cf86d8 upstream. A value of efi.runtime_version is checked before calling update_capsule()/query_variable_info() as follows. But it isn't initialized anywhere. <snip> static efi_status_t virt_efi_query_variable_info(u32 attr, u64 *storage_space, u64 *remaining_space, u64 *max_variable_size) { if (efi.runtime_version < EFI_2_00_SYSTEM_TABLE_REVISION) return EFI_UNSUPPORTED; <snip> This patch initializes a value of efi.runtime_version at boot time. Signed-off-by:
Seiji Aguchi <seiji.aguchi@hds.com> Acked-by:
Matthew Garrett <mjg@redhat.com> Signed-off-by:
Matt Fleming <matt.fleming@intel.com> Signed-off-by:
Ivan Hu <ivan.hu@canonical.com> Signed-off-by:
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Matthew Garrett authored
commit 9dead5bb upstream. We can't assume the presence of the red zone while we're still in a boot services environment, so we should build with -fno-red-zone to avoid problems. Change the size of wchar at the same time to make string handling simpler. Signed-off-by:
Josh Boyer <jwboyer@redhat.com> Signed-off-by:
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Mel Gorman authored
commit 00442ad0 upstream. Commit cc9a6c87 ("cpuset: mm: reduce large amounts of memory barrier related damage v3") introduced a potential memory corruption. shmem_alloc_page() uses a pseudo vma and it has one significant unique combination, vma->vm_ops=NULL and vma->policy->flags & MPOL_F_SHARED. get_vma_policy() does NOT increase a policy ref when vma->vm_ops=NULL and mpol_cond_put() DOES decrease a policy ref when a policy has MPOL_F_SHARED. Therefore, when a cpuset update race occurs, alloc_pages_vma() falls in 'goto retry_cpuset' path, decrements the reference count and frees the policy prematurely. Signed-off-by:
KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Signed-off-by:
Mel Gorman <mgorman@suse.de> Reviewed-by:
Christoph Lameter <cl@linux.com> Cc: Josh Boyer <jwboyer@gmail.com> Signed-off-by:
Andrew Morton <akpm@linux-foundation.org> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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KOSAKI Motohiro authored
commit 63f74ca2 upstream. When shared_policy_replace() fails to allocate new->policy is not freed correctly by mpol_set_shared_policy(). The problem is that shared mempolicy code directly call kmem_cache_free() in multiple places where it is easy to make a mistake. This patch creates an sp_free wrapper function and uses it. The bug was introduced pre-git age (IOW, before 2.6.12-rc2). [mgorman@suse.de: Editted changelog] Signed-off-by:
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Mel Gorman authored
commit b22d127a upstream. shared_policy_replace() use of sp_alloc() is unsafe. 1) sp_node cannot be dereferenced if sp->lock is not held and 2) another thread can modify sp_node between spin_unlock for allocating a new sp node and next spin_lock. The bug was introduced before 2.6.12-rc2. Kosaki's original patch for this problem was to allocate an sp node and policy within shared_policy_replace and initialise it when the lock is reacquired. I was not keen on this approach because it partially duplicates sp_alloc(). As the paths were sp->lock is taken are not that performance critical this patch converts sp->lock to sp->mutex so it can sleep when calling sp_alloc(). [kosaki.motohiro@jp.fujitsu.com: Original patch] Signed-off-by:
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KOSAKI Motohiro authored
commit 869833f2 upstream. Dave Jones' system call fuzz testing tool "trinity" triggered the following bug error with slab debugging enabled ============================================================================= BUG numa_policy (Not tainted): Poison overwritten ----------------------------------------------------------------------------- INFO: 0xffff880146498250-0xffff880146498250. First byte 0x6a instead of 0x6b INFO: Allocated in mpol_new+0xa3/0x140 age=46310 cpu=6 pid=32154 __slab_alloc+0x3d3/0x445 kmem_cache_alloc+0x29d/0x2b0 mpol_new+0xa3/0x140 sys_mbind+0x142/0x620 system_call_fastpath+0x16/0x1b INFO: Freed in __mpol_put+0x27/0x30 age=46268 cpu=6 pid=32154 __slab_free+0x2e/0x1de kmem_cache_free+0x25a/0x260 __mpol_put+0x27/0x30 remove_vma+0x68/0x90 exit_mmap+0x118/0x140 mmput+0x73/0x110 exit_mm+0x108/0x130 do_exit+0x162/0xb90 do_group_exit+0x4f/0xc0 sys_exit_group+0x17/0x20 system_call_fastpath+0x16/0x1b INFO: Slab 0xffffea0005192600 objects=27 used=27 fp=0x (null) flags=0x20000000004080 INFO: Object 0xffff880146498250 @offset=592 fp=0xffff88014649b9d0 The problem is that the structure is being prematurely freed due to a reference count imbalance. In the following case mbind(addr, len) should replace the memory policies of both vma1 and vma2 and thus they will become to share the same mempolicy and the new mempolicy will have the MPOL_F_SHARED flag. +-------------------+-------------------+ | vma1 | vma2(shmem) | +-------------------+-------------------+ | | addr addr+len alloc_pages_vma() uses get_vma_policy() and mpol_cond_put() pair for maintaining the mempolicy reference count. The current rule is that get_vma_policy() only increments refcount for shmem VMA and mpol_conf_put() only decrements refcount if the policy has MPOL_F_SHARED. In above case, vma1 is not shmem vma and vma->policy has MPOL_F_SHARED! The reference count will be decreased even though was not increased whenever alloc_page_vma() is called. This has been broken since commit [52cd3b07: mempolicy: rework mempolicy Reference Counting] in 2008. There is another serious bug with the sharing of memory policies. Currently, mempolicy rebind logic (it is called from cpuset rebinding) ignores a refcount of mempolicy and override it forcibly. Thus, any mempolicy sharing may cause mempolicy corruption. The bug was introduced by commit [68860ec1: cpusets: automatic numa mempolicy rebinding]. Ideally, the shared policy handling would be rewritten to either properly handle COW of the policy structures or at least reference count MPOL_F_SHARED based exclusively on information within the policy. However, this patch takes the easier approach of disabling any policy sharing between VMAs. Each new range allocated with sp_alloc will allocate a new policy, set the reference count to 1 and drop the reference count of the old policy. This increases the memory footprint but is not expected to be a major problem as mbind() is unlikely to be used for fine-grained ranges. It is also inefficient because it means we allocate a new policy even in cases where mbind_range() could use the new_policy passed to it. However, it is more straight-forward and the change should be invisible to the user. [mgorman@suse.de: Edited changelog] Reported-by:
Dave Jones <davej@redhat.com> Cc: Christoph Lameter <cl@linux.com> Reviewed-by:
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KOSAKI Motohiro authored
commit 8d34694c upstream. Commit 05f144a0 ("mm: mempolicy: Let vma_merge and vma_split handle vma->vm_policy linkages") removed vma->vm_policy updates code but it is the purpose of mbind_range(). Now, mbind_range() is virtually a no-op and while it does not allow memory corruption it is not the right fix. This patch is a revert. [mgorman@suse.de: Edited changelog] Signed-off-by:
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Francois Romieu authored
commit d387b427 upstream. The new 84xx stopped flying below the radars. Signed-off-by:
Francois Romieu <romieu@fr.zoreil.com> Cc: Hayes Wang <hayeswang@realtek.com> Acked-by:
David S. Miller <davem@davemloft.net> Signed-off-by:
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Francois Romieu authored
commit 851e6022 upstream. Suggested by Hayes. Signed-off-by:
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Paul E. McKenney authored
commit a10d206e upstream. Each grace period is supposed to have at least one callback waiting for that grace period to complete. However, if CONFIG_NO_HZ=n, an extra callback-free grace period is no big problem -- it will chew up a tiny bit of CPU time, but it will complete normally. In contrast, CONFIG_NO_HZ=y kernels have the potential for all the CPUs to go to sleep indefinitely, in turn indefinitely delaying completion of the callback-free grace period. Given that nothing is waiting on this grace period, this is also not a problem. That is, unless RCU CPU stall warnings are also enabled, as they are in recent kernels. In this case, if a CPU wakes up after at least one minute of inactivity, an RCU CPU stall warning will result. The reason that no one noticed until quite recently is that most systems have enough OS noise that they will never remain absolutely idle for a full minute. But there are some embedded systems with cut-down userspace configurations that consistently get into this situation. All this begs the question of exactly how a callback-free grace period gets started in the first place. This can happen due to the fact that CPUs do not necessarily agree on which grace period is in progress. If a CPU still believes that the grace period that just completed is still ongoing, it will believe that it has callbacks that need to wait for another grace period, never mind the fact that the grace period that they were waiting for just completed. This CPU can therefore erroneously decide to start a new grace period. Note that this can happen in TREE_RCU and TREE_PREEMPT_RCU even on a single-CPU system: Deadlock considerations mean that the CPU that detected the end of the grace period is not necessarily officially informed of this fact for some time. Once this CPU notices that the earlier grace period completed, it will invoke its callbacks. It then won't have any callbacks left. If no other CPU has any callbacks, we now have a callback-free grace period. This commit therefore makes CPUs check more carefully before starting a new grace period. This new check relies on an array of tail pointers into each CPU's list of callbacks. If the CPU is up to date on which grace periods have completed, it checks to see if any callbacks follow the RCU_DONE_TAIL segment, otherwise it checks to see if any callbacks follow the RCU_WAIT_TAIL segment. The reason that this works is that the RCU_WAIT_TAIL segment will be promoted to the RCU_DONE_TAIL segment as soon as the CPU is officially notified that the old grace period has ended. This change is to cpu_needs_another_gp(), which is called in a number of places. The only one that really matters is in rcu_start_gp(), where the root rcu_node structure's ->lock is held, which prevents any other CPU from starting or completing a grace period, so that the comparison that determines whether the CPU is missing the completion of a grace period is stable. Reported-by:
Becky Bruce <bgillbruce@gmail.com> Reported-by:
Subodh Nijsure <snijsure@grid-net.com> Reported-by:
Paul Walmsley <paul@pwsan.com> Signed-off-by:
Paul E. McKenney <paul.mckenney@linaro.org> Signed-off-by:
Paul E. McKenney <paulmck@linux.vnet.ibm.com> Tested-by:
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Frederic Weisbecker authored
commit 0ee23fda upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in scores's idle loop. Reported-by:
Frederic Weisbecker <fweisbec@gmail.com> Cc: Chen Liqin <liqin.chen@sunplusct.com> Cc: Lennox Wu <lennox.wu@gmail.com> Signed-off-by:
Josh Triplett <josh@joshtriplett.org> Signed-off-by:
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Frederic Weisbecker authored
commit 48ae077c upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the m32r's idle loop. Reported-by:
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Frederic Weisbecker authored
commit c633f9e7 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the Cris's idle loop. Reported-by:
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Frederic Weisbecker authored
commit 4c94cada upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the Alpha's idle loop. Reported-by:
Michael Cree <mcree@orcon.net.nz> Cc: Richard Henderson <rth@twiddle.net> Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru> Cc: Matt Turner <mattst88@gmail.com> Cc: alpha <linux-alpha@vger.kernel.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by:
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Frederic Weisbecker authored
commit 5b57ba37 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the m68k's idle loop. Reported-by:
Geert Uytterhoeven <geert@linux-m68k.org> Cc: m68k <linux-m68k@lists.linux-m68k.org> Signed-off-by:
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Frederic Weisbecker authored
commit 5b0753a9 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the mn10300's idle loop. Reported-by:
David Howells <dhowells@redhat.com> Reviewed-by:
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Frederic Weisbecker authored
commit 41d8fe5b upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the Frv's idle loop. Reported-by:
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Frederic Weisbecker authored
commit 11ad47a0 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the xtensa's idle loop. Reported-by:
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Frederic Weisbecker authored
commit fbe75218 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the parisc's idle loop. Reported-by:
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Frederic Weisbecker authored
commit b2fe1430 upstream. In the old times, the whole idle task was considered as an RCU quiescent state. But as RCU became more and more successful overtime, some RCU read side critical section have been added even in the code of some architectures idle tasks, for tracing for example. So nowadays, rcu_idle_enter() and rcu_idle_exit() must be called by the architecture to tell RCU about the part in the idle loop that doesn't make use of rcu read side critical sections, typically the part that puts the CPU in low power mode. This is necessary for RCU to find the quiescent states in idle in order to complete grace periods. Add this missing pair of calls in the h8300's idle loop. Reported-by:
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Paul E. McKenney authored
commit 93482f4e upstream. Traditionally, the entire idle task served as an RCU quiescent state. But when RCU read side critical sections started appearing within the idle loop, this traditional strategy became untenable. The fix was to create new RCU APIs named rcu_idle_enter() and rcu_idle_exit(), which must be called by each architecture's idle loop so that RCU can tell when it is safe to ignore a given idle CPU. Unfortunately, this fix was never applied to ia64, a shortcoming remedied by this commit. Reported by: Tony Luck <tony.luck@intel.com> Signed-off-by:
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Alex Deucher authored
commit fb6ca6d1 upstream. There are so many quirks, lets just try and force this for all RS690s. See: https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by:
Alex Deucher <alexander.deucher@amd.com> Signed-off-by:
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Alex Deucher authored
commit 3a6d59df upstream. Fixes another system on: https://bugs.freedesktop.org/show_bug.cgi?id=37679Signed-off-by:
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