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2016-01-05x86/mm/pat: Change free_memtype() to support shrinking caseToshi Kani
Using mremap() to shrink the map size of a VM_PFNMAP range causes the following error message, and leaves the pfn range allocated. x86/PAT: test:3493 freeing invalid memtype [mem 0x483200000-0x4863fffff] This is because rbt_memtype_erase(), called from free_memtype() with spin_lock held, only supports to free a whole memtype node in memtype_rbroot. Therefore, this patch changes rbt_memtype_erase() to support a request that shrinks the size of a memtype node for mremap(). memtype_rb_exact_match() is renamed to memtype_rb_match(), and is enhanced to support EXACT_MATCH and END_MATCH in @match_type. Since the memtype_rbroot tree allows overlapping ranges, rbt_memtype_erase() checks with EXACT_MATCH first, i.e. free a whole node for the munmap case. If no such entry is found, it then checks with END_MATCH, i.e. shrink the size of a node from the end for the mremap case. On the mremap case, rbt_memtype_erase() proceeds in two steps, 1) remove the node, and then 2) insert the updated node. This allows proper update of augmented values, subtree_max_end, in the tree. Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: stsp@list.ru Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1450832064-10093-3-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-05x86/mm/pat: Add untrack_pfn_moved for mremapToshi Kani
mremap() with MREMAP_FIXED on a VM_PFNMAP range causes the following WARN_ON_ONCE() message in untrack_pfn(). WARNING: CPU: 1 PID: 3493 at arch/x86/mm/pat.c:985 untrack_pfn+0xbd/0xd0() Call Trace: [<ffffffff817729ea>] dump_stack+0x45/0x57 [<ffffffff8109e4b6>] warn_slowpath_common+0x86/0xc0 [<ffffffff8109e5ea>] warn_slowpath_null+0x1a/0x20 [<ffffffff8106a88d>] untrack_pfn+0xbd/0xd0 [<ffffffff811d2d5e>] unmap_single_vma+0x80e/0x860 [<ffffffff811d3725>] unmap_vmas+0x55/0xb0 [<ffffffff811d916c>] unmap_region+0xac/0x120 [<ffffffff811db86a>] do_munmap+0x28a/0x460 [<ffffffff811dec33>] move_vma+0x1b3/0x2e0 [<ffffffff811df113>] SyS_mremap+0x3b3/0x510 [<ffffffff817793ee>] entry_SYSCALL_64_fastpath+0x12/0x71 MREMAP_FIXED moves a pfnmap from old vma to new vma. untrack_pfn() is called with the old vma after its pfnmap page table has been removed, which causes follow_phys() to fail. The new vma has a new pfnmap to the same pfn & cache type with VM_PAT set. Therefore, we only need to clear VM_PAT from the old vma in this case. Add untrack_pfn_moved(), which clears VM_PAT from a given old vma. move_vma() is changed to call this function with the old vma when VM_PFNMAP is set. move_vma() then calls do_munmap(), and untrack_pfn() is a no-op since VM_PAT is cleared. Reported-by: Stas Sergeev <stsp@list.ru> Signed-off-by: Toshi Kani <toshi.kani@hpe.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Borislav Petkov <bp@suse.de> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/1450832064-10093-2-git-send-email-toshi.kani@hpe.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-29x86/mm: Drop WARN from multi-BAR checkLaura Abbott
ioremapping multiple BARs produces a warning with a message "Your kernel is fine". This message mostly serves to comfort kernel developers. Users do not read the message, they only see the big scary warning which means something must be horribly broken with their system. Less dramatically, the warn also sets the taint flag which makes it difficult to differentiate problems. If the kernel is actually fine as the warning claims it doesn't make sense for it to be tainted. Change the WARN_ONCE to a pr_warn with the caller of the ioremap. Signed-off-by: Laura Abbott <labbott@fedoraproject.org> Link: http://lkml.kernel.org/r/1450728074-31029-1-git-send-email-labbott@fedoraproject.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-29x86/LDT: Print the real LDT base addressJan Beulich
This was meant to print base address and entry count; make it do so again. Fixes: 37868fe113ff "x86/ldt: Make modify_ldt synchronous" Signed-off-by: Jan Beulich <jbeulich@suse.com> Acked-by: Andy Lutomirski <luto@kernel.org> Link: http://lkml.kernel.org/r/56797D8402000078000C24F0@prv-mh.provo.novell.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2015-12-06x86/mm/64: Enable SWIOTLB if system has SRAT memory regions above MAX_DMA32_PFNIgor Mammedov
when memory hotplug enabled system is booted with less than 4GB of RAM and then later more RAM is hotplugged 32-bit devices stop functioning with following error: nommu_map_single: overflow 327b4f8c0+1522 of device mask ffffffff the reason for this is that if x86_64 system were booted with RAM less than 4GB, it doesn't enable SWIOTLB and when memory is hotplugged beyond MAX_DMA32_PFN, devices that expect 32-bit addresses can't handle 64-bit addresses. Fix it by tracking max possible PFN when parsing memory affinity structures from SRAT ACPI table and enable SWIOTLB if there is hotpluggable memory regions beyond MAX_DMA32_PFN. It fixes KVM guests when they use emulated devices (reproduces with ata_piix, e1000 and usb devices, RHBZ: 1275941, 1275977, 1271527) It also fixes the HyperV, VMWare with emulated devices which are affected by this issue as well. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akataria@vmware.com Cc: fujita.tomonori@lab.ntt.co.jp Cc: konrad.wilk@oracle.com Cc: pbonzini@redhat.com Cc: revers@redhat.com Cc: riel@redhat.com Link: http://lkml.kernel.org/r/1449234426-273049-3-git-send-email-imammedo@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-06x86/mm: Introduce max_possible_pfnIgor Mammedov
max_possible_pfn will be used for tracking max possible PFN for memory that isn't present in E820 table and could be hotplugged later. By default max_possible_pfn is initialized with max_pfn, but later it could be updated with highest PFN of hotpluggable memory ranges declared in ACPI SRAT table if any present. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: akataria@vmware.com Cc: fujita.tomonori@lab.ntt.co.jp Cc: konrad.wilk@oracle.com Cc: pbonzini@redhat.com Cc: revers@redhat.com Cc: riel@redhat.com Link: http://lkml.kernel.org/r/1449234426-273049-2-git-send-email-imammedo@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04x86/mm/ptdump: Make (debugfs)/kernel_page_tables read-onlyBorislav Petkov
File should be created with S_IRUSR and not with S_IWUSR too because writing to it doesn't make any sense. I mean, we don't have a ->write method anyway but let's have the permissions correct too. Signed-off-by: Borislav Petkov <bp@suse.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1448885579-32506-1-git-send-email-bp@alien8.de Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-12-04x86/mm/mtrr: Mark the 'range_new' static variable in mtrr_calc_range_state() ↵Rasmus Villemoes
as __initdata 'range_new' doesn't seem to be used after init. It is only passed to memset(), sum_ranges(), memcmp() and x86_get_mtrr_mem_range(), the latter of which also only passes it on to various *range* library functions. So mark it __initdata to free up an extra page after init. Its contents are wiped at every call to mtrr_calc_range_state(), so it being static is not about preserving state between calls, but simply to avoid a 4k+ stack frame. While there, add a comment explaining this and why it's safe. We could also mark nr_range_new as __initdata, but since it's just a single int and also doesn't carry state between calls (it is unconditionally assigned to before it is read), we might as well make it an ordinary automatic variable. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/1449002691-20783-1-git-send-email-linux@rasmusvillemoes.dk Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-23x86/mm: Turn CONFIG_X86_PTDUMP into a moduleKees Cook
Being able to examine page tables is handy, so make this a module that can be loaded as needed. Signed-off-by: Kees Cook <keescook@chromium.org> Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hpe.com> Cc: Vladimir Murzin <vladimir.murzin@arm.com> Cc: Will Deacon <will.deacon@arm.com> Link: http://lkml.kernel.org/r/20151120010755.GA9060@www.outflux.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-11-22Linux 4.4-rc2Linus Torvalds
2015-11-22Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge slub bulk allocator updates from Andrew Morton: "This missed the merge window because I was waiting for some repairs to come in. Nothing actually uses the bulk allocator yet and the changes to other code paths are pretty small. And the net guys are waiting for this so they can start merging the client code" More comments from Jesper Dangaard Brouer: "The kmem_cache_alloc_bulk() call, in mm/slub.c, were included in previous kernel. The present version contains a bug. Vladimir Davydov noticed it contained a bug, when kernel is compiled with CONFIG_MEMCG_KMEM (see commit 03ec0ed57ffc: "slub: fix kmem cgroup bug in kmem_cache_alloc_bulk"). Plus the mem cgroup counterpart in kmem_cache_free_bulk() were missing (see commit 033745189b1b "slub: add missing kmem cgroup support to kmem_cache_free_bulk"). I don't consider the fix stable-material because there are no in-tree users of the API. But with known bugs (for memcg) I cannot start using the API in the net-tree" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: slab/slub: adjust kmem_cache_alloc_bulk API slub: add missing kmem cgroup support to kmem_cache_free_bulk slub: fix kmem cgroup bug in kmem_cache_alloc_bulk slub: optimize bulk slowpath free by detached freelist slub: support for bulk free with SLUB freelists
2015-11-22Merge tag 'tty-4.4-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are a few small tty/serial driver fixes for 4.4-rc2 that resolve some reported problems. All have been in linux-next, full details are in the shortlog below" * tag 'tty-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: serial: export fsl8250_handle_irq serial: 8250_mid: Add missing dependency tty: audit: Fix audit source serial: etraxfs-uart: Fix crash serial: fsl_lpuart: Fix earlycon support bcm63xx_uart: Use the device name when registering an interrupt tty: Fix direct use of tty buffer work tty: Fix tty_send_xchar() lock order inversion
2015-11-22Merge tag 'staging-4.4-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging Pull staging/IIO fixes from Greg KH: "Here are some staging and iio driver fixes for 4.4-rc2. All of these are in response to issues that have been reported and have been in linux-next for a while" * tag 'staging-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: Revert "Staging: wilc1000: coreconfigurator: Drop unneeded wrapper functions" iio: adc: xilinx: Fix VREFN scale iio: si7020: Swap data byte order iio: adc: vf610_adc: Fix division by zero error iio:ad7793: Fix ad7785 product ID iio: ad5064: Fix ad5629/ad5669 shift iio:ad5064: Make sure ad5064_i2c_write() returns 0 on success iio: lpc32xx_adc: fix warnings caused by enabling unprepared clock staging: iio: select IRQ_WORK for IIO_DUMMY_EVGEN vf610_adc: Fix internal temperature calculation
2015-11-22Merge tag 'usb-4.4-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb Pull USB fixes from Greg KH: "Here are a number of USB fixes and new device ids for 4.4-rc2. All have been in linux-next and the details are in the shortlog" * tag 'usb-4.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (28 commits) usblp: do not set TASK_INTERRUPTIBLE before lock USB: MAINTAINERS: cxacru usb: kconfig: fix warning of select USB_OTG USB: option: add XS Stick W100-2 from 4G Systems xhci: Fix a race in usb2 LPM resume, blocking U3 for usb2 devices usb: xhci: fix checking ep busy for CFC xhci: Workaround to get Intel xHCI reset working more reliably usb: chipidea: imx: fix a possible NULL dereference usb: chipidea: usbmisc_imx: fix a possible NULL dereference usb: chipidea: otg: gadget module load and unload support usb: chipidea: debug: disable usb irq while role switch ARM: dts: imx27.dtsi: change the clock information for usb usb: chipidea: imx: refine clock operations to adapt for all platforms usb: gadget: atmel_usba_udc: Expose correct device speed usb: musb: enable usb_dma parameter usb: phy: phy-mxs-usb: fix a possible NULL dereference usb: dwc3: gadget: let us set lower max_speed usb: musb: fix tx fifo flush handling usb: gadget: f_loopback: fix the warning during the enumeration usb: dwc2: host: Fix remote wakeup when not in DWC2_L2 ...
2015-11-22Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds
Pull MIPS fixes from Ralf Baechle: - Fix a flood of annoying build warnings - A number of fixes for Atheros 79xx platforms * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: ath79: Add a machine entry for booting OF machines MIPS: ath79: Fix the size of the MISC INTC registers in ar9132.dtsi MIPS: ath79: Fix the DDR control initialization on ar71xx and ar934x MIPS: Fix flood of warnings about comparsion being always true.
2015-11-22Merge branch 'parisc-4.4-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux Pull parisc update from Helge Deller: "This patchset adds Huge Page and HUGETLBFS support for parisc" Honestly, the hugepage support should have gone through in the merge window, and is not really an rc-time fix. But it only touches arch/parisc, and I cannot find it in myself to care. If one of the three parisc users notices a breakage, I will point at Helge and make rude farting noises. * 'parisc-4.4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Map kernel text and data on huge pages parisc: Add Huge Page and HUGETLBFS support parisc: Use long branch to do_syscall_trace_exit parisc: Increase initial kernel mapping to 32MB on 64bit kernel parisc: Initialize the fault vector earlier in the boot process. parisc: Add defines for Huge page support parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.h parisc: Drop definition of start_thread_som for HP-UX SOM binaries parisc: Fix wrong comment regarding first pmd entry flags
2015-11-22Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf tool fixes from Thomas Gleixner: "A couple of fixes for perf tools: - Build system updates - Plug a memory leak in an error path of perf probe - Tear down probes correctly when adding fails - Fixes to the perf symbol handling - Fix ordering of event processing in buildid-list - Fix per DSO filtering in the histogram browser" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf probe: Clear probe_trace_event when add_probe_trace_event() fails perf probe: Fix memory leaking on failure by clearing all probe_trace_events perf inject: Also re-pipe lost_samples event perf buildid-list: Requires ordered events perf symbols: Fix dso lookup by long name and missing buildids perf symbols: Allow forcing reading of non-root owned files by root perf hists browser: The dso can be obtained from popup_action->ms.map->dso perf hists browser: Fix 'd' hotkey action to filter by DSO perf symbols: Rebuild rbtree when adjusting symbols for kcore tools: Add a "make all" rule tools: Actually install tmon in the install rule
2015-11-22Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Thomas Gleixner: "This update contains: - MPX updates for handling 32bit processes - A fix for a long standing bug in 32bit signal frame handling related to FPU/XSAVE state - Handle get_xsave_addr() correctly in KVM - Fix SMAP check under paravirtualization - Add a comment to the static function trace entry to avoid further confusion about the difference to dynamic tracing" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/cpu: Fix SMAP check in PVOPS environments x86/ftrace: Add comment on static function tracing x86/fpu: Fix get_xsave_addr() behavior under virtualization x86/fpu: Fix 32-bit signal frame handling x86/mpx: Fix 32-bit address space calculation x86/mpx: Do proper get_user() when running 32-bit binaries on 64-bit kernels
2015-11-22slab/slub: adjust kmem_cache_alloc_bulk APIJesper Dangaard Brouer
Adjust kmem_cache_alloc_bulk API before we have any real users. Adjust API to return type 'int' instead of previously type 'bool'. This is done to allow future extension of the bulk alloc API. A future extension could be to allow SLUB to stop at a page boundary, when specified by a flag, and then return the number of objects. The advantage of this approach, would make it easier to make bulk alloc run without local IRQs disabled. With an approach of cmpxchg "stealing" the entire c->freelist or page->freelist. To avoid overshooting we would stop processing at a slab-page boundary. Else we always end up returning some objects at the cost of another cmpxchg. To keep compatible with future users of this API linking against an older kernel when using the new flag, we need to return the number of allocated objects with this API change. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22slub: add missing kmem cgroup support to kmem_cache_free_bulkJesper Dangaard Brouer
Initial implementation missed support for kmem cgroup support in kmem_cache_free_bulk() call, add this. If CONFIG_MEMCG_KMEM is not enabled, the compiler should be smart enough to not add any asm code. Incoming bulk free objects can belong to different kmem cgroups, and object free call can happen at a later point outside memcg context. Thus, we need to keep the orig kmem_cache, to correctly verify if a memcg object match against its "root_cache" (s->memcg_params.root_cache). Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22slub: fix kmem cgroup bug in kmem_cache_alloc_bulkJesper Dangaard Brouer
The call slab_pre_alloc_hook() interacts with kmemgc and is not allowed to be called several times inside the bulk alloc for loop, due to the call to memcg_kmem_get_cache(). This would result in hitting the VM_BUG_ON in __memcg_kmem_get_cache. As suggested by Vladimir Davydov, change slab_post_alloc_hook() to be able to handle an array of objects. A subtle detail is, loop iterator "i" in slab_post_alloc_hook() must have same type (size_t) as size argument. This helps the compiler to easier realize that it can remove the loop, when all debug statements inside loop evaluates to nothing. Note, this is only an issue because the kernel is compiled with GCC option: -fno-strict-overflow In slab_alloc_node() the compiler inlines and optimizes the invocation of slab_post_alloc_hook(s, flags, 1, &object) by removing the loop and access object directly. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Reported-by: Vladimir Davydov <vdavydov@virtuozzo.com> Suggested-by: Vladimir Davydov <vdavydov@virtuozzo.com> Reviewed-by: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22slub: optimize bulk slowpath free by detached freelistJesper Dangaard Brouer
This change focus on improving the speed of object freeing in the "slowpath" of kmem_cache_free_bulk. The calls slab_free (fastpath) and __slab_free (slowpath) have been extended with support for bulk free, which amortize the overhead of the (locked) cmpxchg_double. To use the new bulking feature, we build what I call a detached freelist. The detached freelist takes advantage of three properties: 1) the free function call owns the object that is about to be freed, thus writing into this memory is synchronization-free. 2) many freelist's can co-exist side-by-side in the same slab-page each with a separate head pointer. 3) it is the visibility of the head pointer that needs synchronization. Given these properties, the brilliant part is that the detached freelist can be constructed without any need for synchronization. The freelist is constructed directly in the page objects, without any synchronization needed. The detached freelist is allocated on the stack of the function call kmem_cache_free_bulk. Thus, the freelist head pointer is not visible to other CPUs. All objects in a SLUB freelist must belong to the same slab-page. Thus, constructing the detached freelist is about matching objects that belong to the same slab-page. The bulk free array is scanned is a progressive manor with a limited look-ahead facility. Kmem debug support is handled in call of slab_free(). Notice kmem_cache_free_bulk no longer need to disable IRQs. This only slowed down single free bulk with approx 3 cycles. Performance data: Benchmarked[1] obj size 256 bytes on CPU i7-4790K @ 4.00GHz SLUB fastpath single object quick reuse: 47 cycles(tsc) 11.931 ns To get stable and comparable numbers, the kernel have been booted with "slab_merge" (this also improve performance for larger bulk sizes). Performance data, compared against fallback bulking: bulk - fallback bulk - improvement with this patch 1 - 62 cycles(tsc) 15.662 ns - 49 cycles(tsc) 12.407 ns- improved 21.0% 2 - 55 cycles(tsc) 13.935 ns - 30 cycles(tsc) 7.506 ns - improved 45.5% 3 - 53 cycles(tsc) 13.341 ns - 23 cycles(tsc) 5.865 ns - improved 56.6% 4 - 52 cycles(tsc) 13.081 ns - 20 cycles(tsc) 5.048 ns - improved 61.5% 8 - 50 cycles(tsc) 12.627 ns - 18 cycles(tsc) 4.659 ns - improved 64.0% 16 - 49 cycles(tsc) 12.412 ns - 17 cycles(tsc) 4.495 ns - improved 65.3% 30 - 49 cycles(tsc) 12.484 ns - 18 cycles(tsc) 4.533 ns - improved 63.3% 32 - 50 cycles(tsc) 12.627 ns - 18 cycles(tsc) 4.707 ns - improved 64.0% 34 - 96 cycles(tsc) 24.243 ns - 23 cycles(tsc) 5.976 ns - improved 76.0% 48 - 83 cycles(tsc) 20.818 ns - 21 cycles(tsc) 5.329 ns - improved 74.7% 64 - 74 cycles(tsc) 18.700 ns - 20 cycles(tsc) 5.127 ns - improved 73.0% 128 - 90 cycles(tsc) 22.734 ns - 27 cycles(tsc) 6.833 ns - improved 70.0% 158 - 99 cycles(tsc) 24.776 ns - 30 cycles(tsc) 7.583 ns - improved 69.7% 250 - 104 cycles(tsc) 26.089 ns - 37 cycles(tsc) 9.280 ns - improved 64.4% Performance data, compared current in-kernel bulking: bulk - curr in-kernel - improvement with this patch 1 - 46 cycles(tsc) - 49 cycles(tsc) - improved (cycles:-3) -6.5% 2 - 27 cycles(tsc) - 30 cycles(tsc) - improved (cycles:-3) -11.1% 3 - 21 cycles(tsc) - 23 cycles(tsc) - improved (cycles:-2) -9.5% 4 - 18 cycles(tsc) - 20 cycles(tsc) - improved (cycles:-2) -11.1% 8 - 17 cycles(tsc) - 18 cycles(tsc) - improved (cycles:-1) -5.9% 16 - 18 cycles(tsc) - 17 cycles(tsc) - improved (cycles: 1) 5.6% 30 - 18 cycles(tsc) - 18 cycles(tsc) - improved (cycles: 0) 0.0% 32 - 18 cycles(tsc) - 18 cycles(tsc) - improved (cycles: 0) 0.0% 34 - 78 cycles(tsc) - 23 cycles(tsc) - improved (cycles:55) 70.5% 48 - 60 cycles(tsc) - 21 cycles(tsc) - improved (cycles:39) 65.0% 64 - 49 cycles(tsc) - 20 cycles(tsc) - improved (cycles:29) 59.2% 128 - 69 cycles(tsc) - 27 cycles(tsc) - improved (cycles:42) 60.9% 158 - 79 cycles(tsc) - 30 cycles(tsc) - improved (cycles:49) 62.0% 250 - 86 cycles(tsc) - 37 cycles(tsc) - improved (cycles:49) 57.0% Performance with normal SLUB merging is significantly slower for larger bulking. This is believed to (primarily) be an effect of not having to share the per-CPU data-structures, as tuning per-CPU size can achieve similar performance. bulk - slab_nomerge - normal SLUB merge 1 - 49 cycles(tsc) - 49 cycles(tsc) - merge slower with cycles:0 2 - 30 cycles(tsc) - 30 cycles(tsc) - merge slower with cycles:0 3 - 23 cycles(tsc) - 23 cycles(tsc) - merge slower with cycles:0 4 - 20 cycles(tsc) - 20 cycles(tsc) - merge slower with cycles:0 8 - 18 cycles(tsc) - 18 cycles(tsc) - merge slower with cycles:0 16 - 17 cycles(tsc) - 17 cycles(tsc) - merge slower with cycles:0 30 - 18 cycles(tsc) - 23 cycles(tsc) - merge slower with cycles:5 32 - 18 cycles(tsc) - 22 cycles(tsc) - merge slower with cycles:4 34 - 23 cycles(tsc) - 22 cycles(tsc) - merge slower with cycles:-1 48 - 21 cycles(tsc) - 22 cycles(tsc) - merge slower with cycles:1 64 - 20 cycles(tsc) - 48 cycles(tsc) - merge slower with cycles:28 128 - 27 cycles(tsc) - 57 cycles(tsc) - merge slower with cycles:30 158 - 30 cycles(tsc) - 59 cycles(tsc) - merge slower with cycles:29 250 - 37 cycles(tsc) - 56 cycles(tsc) - merge slower with cycles:19 Joint work with Alexander Duyck. [1] https://github.com/netoptimizer/prototype-kernel/blob/master/kernel/mm/slab_bulk_test01.c [akpm@linux-foundation.org: BUG_ON -> WARN_ON;return] Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22slub: support for bulk free with SLUB freelistsJesper Dangaard Brouer
Make it possible to free a freelist with several objects by adjusting API of slab_free() and __slab_free() to have head, tail and an objects counter (cnt). Tail being NULL indicate single object free of head object. This allow compiler inline constant propagation in slab_free() and slab_free_freelist_hook() to avoid adding any overhead in case of single object free. This allows a freelist with several objects (all within the same slab-page) to be free'ed using a single locked cmpxchg_double in __slab_free() and with an unlocked cmpxchg_double in slab_free(). Object debugging on the free path is also extended to handle these freelists. When CONFIG_SLUB_DEBUG is enabled it will also detect if objects don't belong to the same slab-page. These changes are needed for the next patch to bulk free the detached freelists it introduces and constructs. Micro benchmarking showed no performance reduction due to this change, when debugging is turned off (compiled with CONFIG_SLUB_DEBUG). Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-22parisc: Map kernel text and data on huge pagesHelge Deller
Adjust the linker script and map_pages() to map kernel text and data on physical 1MB huge/large pages. Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22parisc: Add Huge Page and HUGETLBFS supportHelge Deller
This patch adds huge page support to allow userspace to allocate huge pages and to use hugetlbfs filesystem on 32- and 64-bit Linux kernels. A later patch will add kernel support to map kernel text and data on huge pages. The only requirement is, that the kernel needs to be compiled for a PA8X00 CPU (PA2.0 architecture). Older PA1.X CPUs do not support variable page sizes. 64bit Kernels are compiled for PA2.0 by default. Technically on parisc multiple physical huge pages may be needed to emulate standard 2MB huge pages. Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22parisc: Use long branch to do_syscall_trace_exitHelge Deller
Use the 22bit instead of the 17bit branch instruction on a 64bit kernel to reach the do_syscall_trace_exit function from the gateway page. A huge page enabled kernel may need the additional branch distance bits. Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22parisc: Increase initial kernel mapping to 32MB on 64bit kernelHelge Deller
For the 64bit kernel the initially 16 MB kernel memory might become too small if you build a kernel with many modules built-in and with kernel text and data areas mapped on huge pages. This patch increases the initial mapping to 32MB for 64bit kernels and keeps 16MB for 32bit kernels. Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22parisc: Initialize the fault vector earlier in the boot process.Helge Deller
A fault vector on parisc needs to be 2K aligned. Furthermore the checksum of the fault vector needs to sum up to 0 which is being calculated and written at runtime. Up to now we aligned both PA20 and PA11 fault vectors on the same 4K page in order to easily write the checksum after having mapped the kernel read-only (by mapping this page only as read-write). But when we want to map the kernel text and data on huge pages this makes things harder. So, simplify it by aligning both fault vectors on 2K boundries and write the checksum before we map the page read-only. Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22parisc: Add defines for Huge page supportHelge Deller
Huge pages on parisc will have the same size as one pmd table, which is on a 64bit kernel 2MB on a kernel with 4K kernel page sizes, and on a 32bit kernel 4MB when used with 4K kernel pages. Since parisc does not physically supports 2MB huge page sizes, emulate it with two consecutive 1MB page sizes instead. Keeping the same huge page size as one pmd will allow us to add transparent huge page support later on. Bit 21 in the pte flags was unused and will now be used to mark a page as huge page (_PAGE_HPAGE_BIT). Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-22parisc: Drop unused MADV_xxxK_PAGES flags from asm/mman.hHelge Deller
Drop the MADV_xxK_PAGES flags, which were never used and were from a proposed API which was never integrated into the generic Linux kernel code. Cc: stable@vger.kernel.org Signed-off-by: Helge Deller <deller@gmx.de>
2015-11-21Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "A bunch of fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: slub: mark the dangling ifdef #else of CONFIG_SLUB_DEBUG slub: avoid irqoff/on in bulk allocation slub: create new ___slab_alloc function that can be called with irqs disabled mm: fix up sparse warning in gfpflags_allow_blocking ocfs2: fix umask ignored issue PM/OPP: add entry in MAINTAINERS kernel/panic.c: turn off locks debug before releasing console lock kernel/signal.c: unexport sigsuspend() kasan: fix kmemleak false-positive in kasan_module_alloc() fat: fix fake_offset handling on error path mm/hugetlbfs: fix bugs in fallocate hole punch of areas with holes mm/page-writeback.c: initialize m_dirty to avoid compile warning various: fix pci_set_dma_mask return value checking mm: loosen MADV_NOHUGEPAGE to enable Qemu postcopy on s390 mm: vmalloc: don't remove inexistent guard hole in remove_vm_area() tools/vm/page-types.c: support KPF_IDLE ncpfs: don't allow negative timeouts configfs: allow dynamic group creation MAINTAINERS: add Moritz as reviewer for FPGA Manager Framework slab.h: sprinkle __assume_aligned attributes
2015-11-21Merge branch 'timers-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull timer fixes from Thomas Gleixner: "Two timer fixlets from Arnd: - Use proper constant size in the FSL timer driver - Prevent a build error for legacy platforms" * 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: clocksource: Disallow drivers for ARCH_USES_GETTIMEOFFSET clocksource/fsl: Avoid harmless 64-bit warnings
2015-11-21Merge branch 'irq-urgent-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull irq fixes from Thomas Gleixner: "Three fixes for the ARM GIC interrupt controller from Marc addressing various shortcomings versus boot initialization and suspend/resume" * 'irq-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: irqchip/gic: Add save/restore of the active state irqchip/gic: Clear enable bits before restoring them irqchip/gic: Make sure all interrupts are deactivated at boot
2015-11-21Merge tag 'for-linus-20151120' of git://git.infradead.org/linux-mtdLinus Torvalds
Pull MTD fixes from Brian Norris: - MAINTAINERS updates for brcmnand driver - Fix reboot hangs seen when multiple NAND flash chips are registered with the same controller - Fix build issues on jz4740 NAND driver; the error was introduced in 4.3, so I guess nobody really cared, but we might as well fix it * tag 'for-linus-20151120' of git://git.infradead.org/linux-mtd: MAINTAINERS: brcmnand: Add co-maintainer for Broadcom SoCs MAINTAINERS: brcmnand: Add Broadcom internal mailing-list mtd: nand: fix shutdown/reboot for multi-chip systems mtd: jz4740_nand: fix build on jz4740 after removing gpio.h
2015-11-20serial: export fsl8250_handle_irqArnd Bergmann
fsl8250_handle_irq is now used by the of_serial driver, and that fails if it is a loadable module: ERROR: "fsl8250_handle_irq" [drivers/tty/serial/of_serial.ko] undefined! This exports the symbol to avoid randconfig errors. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: d43b54d269d2 ("serial: Enable Freescale 16550 workaround on arm") Cc: Scott Wood <scottwood@freescale.com> Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20serial: 8250_mid: Add missing dependencyHeikki Krogerus
8250_mid uses rational_best_approximation() function, so the driver needs to select CONFIG_RATIONAL option. This fixes build error when CONFIG_RATIONAL is not enabled: drivers/built-in.o: In function `mid8250_set_termios': 8250_mid.c:(.text+0x10169a): undefined reference to `rational_best_approximation' Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com> Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20tty: audit: Fix audit sourcePeter Hurley
The data to audit/record is in the 'from' buffer (ie., the input read buffer). Fixes: 72586c6061ab ("n_tty: Fix auditing support for cannonical mode") Cc: stable <stable@vger.kernel.org> # 4.1+ Cc: Miloslav Trmač <mitr@redhat.com> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Laura Abbott <labbott@fedoraproject.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20serial: etraxfs-uart: Fix crashGuenter Roeck
Since commit 7d8c70d8048c ("serial: mctrl-gpio: rename init function"), crisv32 either do not build or crash as follows. Unable to handle kernel NULL pointer dereference Linux 4.3.0-rc7-next-20151101 #1 Sun Nov 1 11:41:28 PST 2015 ... Call Trace: [<c0004a0e>] show_stack+0x0/0x9e [<c004c0c0>] printk+0x0/0x2c [<c00059d4>] show_registers+0x14a/0x1c2 [<c004c0c0>] printk+0x0/0x2c [<c0004b52>] die_if_kernel+0x7c/0x9e [<c0005346>] do_page_fault+0x32e/0x3e6 [<c01dc59c>] of_get_property+0x0/0x2c [<c01e0558>] of_irq_parse_raw+0x12a/0x376 [<c01dc59c>] of_get_property+0x0/0x2c [<c0053aca>] get_page_from_freelist+0x73e/0x856 [<c01dc59c>] of_get_property+0x0/0x2c [<c0008912>] d_mmu_refill+0x10a/0x112 [<c01b488c>] devm_kmalloc+0x40/0x56 [<c01b47d0>] add_dr+0xc/0x1c [<c01b4800>] devm_add_action+0x2/0x4e [<c01abdbc>] mctrl_gpio_init_noauto+0x1c/0x76 [<c01abf9e>] mctrl_gpio_init+0x22/0x110 The function call in the etraxfs-uart driver was not renamed, possibly due to interference with commit 7b9c5162c182 ("serial: etraxfs-uart: use mctrl_gpio helpers for handling modem signals"). Fixes: 7d8c70d8048c ("serial: mctrl-gpio: rename init function") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Niklas Cassel <nks@flawful.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20serial: fsl_lpuart: Fix earlycon supportPeter Hurley
Earlycon support for Freescale lpuart should only be enabled when console support is enabled. Fixes: 1d59b382f1c4 ("serial: fsl_lpuart: add earlycon support") Acked-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20bcm63xx_uart: Use the device name when registering an interruptSimon Arlott
Use the device name when registering an interrupt so that multiple ports don't all have the same interrupt name. Signed-off-by: Simon Arlott <simon@fire.lp0.eu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20tty: Fix direct use of tty buffer workPeter Hurley
Recent abstraction of tty buffer work introduced api to manage tty input kworker; use it. Fixes: e176058f0de5 ("tty: Abstract tty buffer work") Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20tty: Fix tty_send_xchar() lock order inversionPeter Hurley
The correct lock order is atomic_write_lock => termios_rwsem, as established by tty_write() => n_tty_write(). Fixes: c274f6ef1c666 ("tty: Hold termios_rwsem for tcflow(TCIxxx)") Reported-and-Tested-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> # v3.18+ Signed-off-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-20slub: mark the dangling ifdef #else of CONFIG_SLUB_DEBUGJesper Dangaard Brouer
The #ifdef of CONFIG_SLUB_DEBUG is located very far from the associated #else. For readability mark it with a comment. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20slub: avoid irqoff/on in bulk allocationChristoph Lameter
Use the new function that can do allocation while interrupts are disabled. Avoids irq on/off sequences. Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20slub: create new ___slab_alloc function that can be called with irqs disabledChristoph Lameter
Bulk alloc needs a function like that because it enables interrupts before calling __slab_alloc which promptly disables them again using the expensive local_irq_save(). Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Jesper Dangaard Brouer <brouer@redhat.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Alexander Duyck <alexander.h.duyck@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20mm: fix up sparse warning in gfpflags_allow_blockingJeff Layton
sparse says: include/linux/gfp.h:274:26: warning: incorrect type in return expression (different base types) include/linux/gfp.h:274:26: expected bool include/linux/gfp.h:274:26: got restricted gfp_t ...add a forced cast to silence the warning. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20ocfs2: fix umask ignored issueJunxiao Bi
New created file's mode is not masked with umask, and this makes umask not work for ocfs2 volume. Fixes: 702e5bc ("ocfs2: use generic posix ACL infrastructure") Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Gang He <ghe@suse.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20PM/OPP: add entry in MAINTAINERSViresh Kumar
Add entry for operating performance points into MAINTAINERS file. This will also allow get_maintainers to list OPP stakeholders properly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Rafael Wysocki <rjw@rjwysocki.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20kernel/panic.c: turn off locks debug before releasing console lockVitaly Kuznetsov
Commit 08d78658f393 ("panic: release stale console lock to always get the logbuf printed out") introduced an unwanted bad unlock balance report when panic() is called directly and not from OOPS (e.g. from out_of_memory()). The difference is that in case of OOPS we disable locks debug in oops_enter() and on direct panic call nobody does that. Fixes: 08d78658f393 ("panic: release stale console lock to always get the logbuf printed out") Reported-by: kernel test robot <ying.huang@linux.intel.com> Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Baoquan He <bhe@redhat.com> Cc: Prarit Bhargava <prarit@redhat.com> Cc: Xie XiuQi <xiexiuqi@huawei.com> Cc: Seth Jennings <sjenning@redhat.com> Cc: "K. Y. Srinivasan" <kys@microsoft.com> Cc: Jan Kara <jack@suse.cz> Cc: Petr Mladek <pmladek@suse.cz> Cc: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-11-20kernel/signal.c: unexport sigsuspend()Richard Weinberger
sigsuspend() is nowhere used except in signal.c itself, so we can mark it static do not pollute the global namespace. But this patch is more than a boring cleanup patch, it fixes a real issue on UserModeLinux. UML has a special console driver to display ttys using xterm, or other terminal emulators, on the host side. Vegard reported that sometimes UML is unable to spawn a xterm and he's facing the following warning: WARNING: CPU: 0 PID: 908 at include/linux/thread_info.h:128 sigsuspend+0xab/0xc0() It turned out that this warning makes absolutely no sense as the UML xterm code calls sigsuspend() on the host side, at least it tries. But as the kernel itself offers a sigsuspend() symbol the linker choose this one instead of the glibc wrapper. Interestingly this code used to work since ever but always blocked signals on the wrong side. Some recent kernel change made the WARN_ON() trigger and uncovered the bug. It is a wonderful example of how much works by chance on computers. :-) Fixes: 68f3f16d9ad0f1 ("new helper: sigsuspend()") Signed-off-by: Richard Weinberger <richard@nod.at> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Tested-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: <stable@vger.kernel.org> [3.5+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>