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* Merge branch 'work.misc' of ↵Linus Torvalds2017-05-091-2/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted bits and pieces from various people. No common topic in this pile, sorry" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs/affs: add rename exchange fs/affs: add rename2 to prepare multiple methods Make stat/lstat/fstatat pass AT_NO_AUTOMOUNT to vfs_statx() fs: don't set *REFERENCED on single use objects fs: compat: Remove warning from COMPATIBLE_IOCTL remove pointless extern of atime_need_update_rcu() fs: completely ignore unknown open flags fs: add a VALID_OPEN_FLAGS fs: remove _submit_bh() fs: constify tree_descr arrays passed to simple_fill_super() fs: drop duplicate header percpu-rwsem.h fs/affs: bugfix: Write files greater than page size on OFS fs/affs: bugfix: enable writes on OFS disks fs/affs: remove node generation check fs/affs: import amigaffs.h fs/affs: bugfix: make symbolic links work again
| * fs: constify tree_descr arrays passed to simple_fill_super()Eric Biggers2017-04-261-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | simple_fill_super() is passed an array of tree_descr structures which describe the files to create in the filesystem's root directory. Since these arrays are never modified intentionally, they should be 'const' so that they are placed in .rodata and benefit from memory protection. This patch updates the function signature and all users, and also constifies tree_descr.name. Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | treewide: use kv[mz]alloc* rather than opencoded variantsMichal Hocko2017-05-081-13/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are many code paths opencoding kvmalloc. Let's use the helper instead. The main difference to kvmalloc is that those users are usually not considering all the aspects of the memory allocator. E.g. allocation requests <= 32kB (with 4kB pages) are basically never failing and invoke OOM killer to satisfy the allocation. This sounds too disruptive for something that has a reasonable fallback - the vmalloc. On the other hand those requests might fallback to vmalloc even when the memory allocator would succeed after several more reclaim/compaction attempts previously. There is no guarantee something like that happens though. This patch converts many of those places to kv[mz]alloc* helpers because they are more conservative. Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390 Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim Acked-by: David Sterba <dsterba@suse.com> # btrfs Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4 Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5 Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: Anton Vorontsov <anton@enomsg.org> Cc: Colin Cross <ccross@android.com> Cc: Tony Luck <tony.luck@intel.com> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net> Cc: Ben Skeggs <bskeggs@redhat.com> Cc: Kent Overstreet <kent.overstreet@gmail.com> Cc: Santosh Raspatur <santosh@chelsio.com> Cc: Hariprasad S <hariprasad@chelsio.com> Cc: Yishai Hadas <yishaih@mellanox.com> Cc: Oleg Drokin <oleg.drokin@intel.com> Cc: "Yan, Zheng" <zyan@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: David Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | xen: Implement EFI reset_system callbackJulien Grall2017-05-021-0/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When rebooting DOM0 with ACPI on ARM64, the kernel is crashing with the stack trace [1]. This is happening because when EFI runtimes are enabled, the reset code (see machine_restart) will first try to use EFI restart method. However, the EFI restart code is expecting the reset_system callback to be always set. This is not the case for Xen and will lead to crash. The EFI restart helper is used in multiple places and some of them don't not have fallback (see machine_power_off). So implement reset_system callback as a call to xen_reboot when using EFI Xen. [ 36.999270] reboot: Restarting system [ 37.002921] Internal error: Attempting to execute userspace memory: 86000004 [#1] PREEMPT SMP [ 37.011460] Modules linked in: [ 37.014598] CPU: 0 PID: 1 Comm: systemd-shutdow Not tainted 4.11.0-rc1-00003-g1e248b60a39b-dirty #506 [ 37.023903] Hardware name: (null) (DT) [ 37.027734] task: ffff800902068000 task.stack: ffff800902064000 [ 37.033739] PC is at 0x0 [ 37.036359] LR is at efi_reboot+0x94/0xd0 [ 37.040438] pc : [<0000000000000000>] lr : [<ffff00000880f2c4>] pstate: 404001c5 [ 37.047920] sp : ffff800902067cf0 [ 37.051314] x29: ffff800902067cf0 x28: ffff800902068000 [ 37.056709] x27: ffff000008992000 x26: 000000000000008e [ 37.062104] x25: 0000000000000123 x24: 0000000000000015 [ 37.067499] x23: 0000000000000000 x22: ffff000008e6e250 [ 37.072894] x21: ffff000008e6e000 x20: 0000000000000000 [ 37.078289] x19: ffff000008e5d4c8 x18: 0000000000000010 [ 37.083684] x17: 0000ffffa7c27470 x16: 00000000deadbeef [ 37.089079] x15: 0000000000000006 x14: ffff000088f42bef [ 37.094474] x13: ffff000008f42bfd x12: ffff000008e706c0 [ 37.099870] x11: ffff000008e70000 x10: 0000000005f5e0ff [ 37.105265] x9 : ffff800902067a50 x8 : 6974726174736552 [ 37.110660] x7 : ffff000008cc6fb8 x6 : ffff000008cc6fb0 [ 37.116055] x5 : ffff000008c97dd8 x4 : 0000000000000000 [ 37.121453] x3 : 0000000000000000 x2 : 0000000000000000 [ 37.126845] x1 : 0000000000000000 x0 : 0000000000000000 [ 37.132239] [ 37.133808] Process systemd-shutdow (pid: 1, stack limit = 0xffff800902064000) [ 37.141118] Stack: (0xffff800902067cf0 to 0xffff800902068000) [ 37.146949] 7ce0: ffff800902067d40 ffff000008085334 [ 37.154869] 7d00: 0000000000000000 ffff000008f3b000 ffff800902067d40 ffff0000080852e0 [ 37.162787] 7d20: ffff000008cc6fb0 ffff000008cc6fb8 ffff000008c7f580 ffff000008c97dd8 [ 37.170706] 7d40: ffff800902067d60 ffff0000080e2c2c 0000000000000000 0000000001234567 [ 37.178624] 7d60: ffff800902067d80 ffff0000080e2ee8 0000000000000000 ffff0000080e2df4 [ 37.186544] 7d80: 0000000000000000 ffff0000080830f0 0000000000000000 00008008ff1c1000 [ 37.194462] 7da0: ffffffffffffffff 0000ffffa7c4b1cc 0000000000000000 0000000000000024 [ 37.202380] 7dc0: ffff800902067dd0 0000000000000005 0000fffff24743c8 0000000000000004 [ 37.210299] 7de0: 0000fffff2475f03 0000000000000010 0000fffff2474418 0000000000000005 [ 37.218218] 7e00: 0000fffff2474578 000000000000000a 0000aaaad6b722c0 0000000000000001 [ 37.226136] 7e20: 0000000000000123 0000000000000038 ffff800902067e50 ffff0000081e7294 [ 37.234055] 7e40: ffff800902067e60 ffff0000081e935c ffff800902067e60 ffff0000081e9388 [ 37.241973] 7e60: ffff800902067eb0 ffff0000081ea388 0000000000000000 00008008ff1c1000 [ 37.249892] 7e80: ffffffffffffffff 0000ffffa7c4a79c 0000000000000000 ffff000000020000 [ 37.257810] 7ea0: 0000010000000004 0000000000000000 0000000000000000 ffff0000080830f0 [ 37.265729] 7ec0: fffffffffee1dead 0000000028121969 0000000001234567 0000000000000000 [ 37.273651] 7ee0: ffffffffffffffff 8080000000800000 0000800000008080 feffa9a9d4ff2d66 [ 37.281567] 7f00: 000000000000008e feffa9a9d5b60e0f 7f7fffffffff7f7f 0101010101010101 [ 37.289485] 7f20: 0000000000000010 0000000000000008 000000000000003a 0000ffffa7ccf588 [ 37.297404] 7f40: 0000aaaad6b87d00 0000ffffa7c4b1b0 0000fffff2474be0 0000aaaad6b88000 [ 37.305326] 7f60: 0000fffff2474fb0 0000000001234567 0000000000000000 0000000000000000 [ 37.313240] 7f80: 0000000000000000 0000000000000001 0000aaaad6b70d4d 0000000000000000 [ 37.321159] 7fa0: 0000000000000001 0000fffff2474ea0 0000aaaad6b5e2e0 0000fffff2474e80 [ 37.329078] 7fc0: 0000ffffa7c4b1cc 0000000000000000 fffffffffee1dead 000000000000008e [ 37.336997] 7fe0: 0000000000000000 0000000000000000 9ce839cffee77eab fafdbf9f7ed57f2f [ 37.344911] Call trace: [ 37.347437] Exception stack(0xffff800902067b20 to 0xffff800902067c50) [ 37.353970] 7b20: ffff000008e5d4c8 0001000000000000 0000000080f82000 0000000000000000 [ 37.361883] 7b40: ffff800902067b60 ffff000008e17000 ffff000008f44c68 00000001081081b4 [ 37.369802] 7b60: ffff800902067bf0 ffff000008108478 0000000000000000 ffff000008c235b0 [ 37.377721] 7b80: ffff800902067ce0 0000000000000000 0000000000000000 0000000000000015 [ 37.385643] 7ba0: 0000000000000123 000000000000008e ffff000008992000 ffff800902068000 [ 37.393557] 7bc0: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [ 37.401477] 7be0: 0000000000000000 ffff000008c97dd8 ffff000008cc6fb0 ffff000008cc6fb8 [ 37.409396] 7c00: 6974726174736552 ffff800902067a50 0000000005f5e0ff ffff000008e70000 [ 37.417318] 7c20: ffff000008e706c0 ffff000008f42bfd ffff000088f42bef 0000000000000006 [ 37.425234] 7c40: 00000000deadbeef 0000ffffa7c27470 [ 37.430190] [< (null)>] (null) [ 37.434982] [<ffff000008085334>] machine_restart+0x6c/0x70 [ 37.440550] [<ffff0000080e2c2c>] kernel_restart+0x6c/0x78 [ 37.446030] [<ffff0000080e2ee8>] SyS_reboot+0x130/0x228 [ 37.451337] [<ffff0000080830f0>] el0_svc_naked+0x24/0x28 [ 37.456737] Code: bad PC value [ 37.459891] ---[ end trace 76e2fc17e050aecd ]--- Signed-off-by: Julien Grall <julien.grall@arm.com> -- Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Juergen Gross <jgross@suse.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: x86@kernel.org The x86 code has theoritically a similar issue, altought EFI does not seem to be the preferred method. I have only built test it on x86. This should also probably be fixed in stable tree. Changes in v2: - Implement xen_efi_reset_system using xen_reboot - Move xen_efi_reset_system in drivers/xen/efi.c Signed-off-by: Juergen Gross <jgross@suse.com>
* | xen: Revert commits da72ff5bfcb0 and 72a9b186292dBoris Ostrovsky2017-05-022-18/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent discussion (http://marc.info/?l=xen-devel&m=149192184523741) established that commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") (and thus commit da72ff5bfcb0 ("partially revert "xen: Remove event channel notification through Xen PCI platform device"")) are unnecessary and, in fact, prevent HVM guests from booting on Xen releases prior to 4.0 Therefore we revert both of those commits. The summary of that discussion is below: Here is the brief summary of the current situation: Before the offending commit (72a9b186292): 1) INTx does not work because of the reset_watches path. 2) The reset_watches path is only taken if you have Xen > 4.0 3) The Linux Kernel by default will use vector inject if the hypervisor support. So even INTx does not work no body running the kernel with Xen > 4.0 would notice. Unless he explicitly disabled this feature either in the kernel or in Xen (and this can only be disabled by modifying the code, not user-supported way to do it). After the offending commit (+ partial revert): 1) INTx is no longer support for HVM (only for PV guests). 2) Any HVM guest The kernel will not boot on Xen < 4.0 which does not have vector injection support. Since the only other mode supported is INTx which. So based on this summary, I think before commit (72a9b186292) we were in much better position from a user point of view. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* | xen/arm,arm64: rename __generic_dma_ops to xen_get_dma_opsStefano Stabellini2017-05-021-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that __generic_dma_ops is a xen specific function, rename it to xen_get_dma_ops. Change all the call sites appropriately. Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> CC: linux@armlinux.org.uk CC: catalin.marinas@arm.com CC: will.deacon@arm.com CC: boris.ostrovsky@oracle.com CC: jgross@suse.com CC: Julien Grall <julien.grall@arm.com>
* | xen/balloon: decorate PV-only parts with #ifdef CONFIG_XEN_PVVitaly Kuznetsov2017-05-021-10/+20
|/ | | | | | | | | | Balloon driver uses several PV-only concepts (xen_start_info, xen_extra_mem,..) and it seems the simpliest solution to make HVM-only build happy is to decorate these parts with #ifdefs. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* xenbus: remove transaction holder from list before freeingJan Beulich2017-04-041-1/+3
| | | | | | | | | | | | | After allocation the item is being placed on the list right away. Consequently it needs to be taken off the list before freeing in the case xenbus_dev_request_and_reply() failed, as in that case the callback (xenbus_dev_queue_reply()) is not being called (and if it was called, it should do both). Fixes: 5584ea250ae44f929feb4c7bd3877d1c5edbf813 Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/acpi: upload PM state from init-domain to XenAnkur Arora2017-03-231-8/+26
| | | | | | | | | | | | | | | | | | | | This was broken in commit cd979883b9ed ("xen/acpi-processor: fix enabling interrupts on syscore_resume"). do_suspend (from xen/manage.c) and thus xen_resume_notifier never get called on the initial-domain at resume (it is if running as guest.) The rationale for the breaking change was that upload_pm_data() potentially does blocking work in syscore_resume(). This patch addresses the original issue by scheduling upload_pm_data() to execute in workqueue context. Cc: Stanislaw Gruszka <sgruszka@redhat.com> Cc: stable@vger.kernel.org Based-on-patch-by: Konrad Wilk <konrad.wilk@oracle.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reviewed-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* xen/acpi: Replace hard coded "ACPI0007"Ankur Arora2017-03-231-1/+1
| | | | | | | | Replace hard coded "ACPI0007" with ACPI_PROCESSOR_DEVICE_HID Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* drivers, xen: convert grant_map.users from atomic_t to refcount_tElena Reshetova2017-03-131-5/+6
| | | | | | | | | | | | | | refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* Merge tag 'for-linus-4.11-rc1-tag' of ↵Linus Torvalds2017-03-091-1/+0
|\ | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fix and cleanup from Juergen Gross: "This contains one fix for MSIX handling under Xen and a trivial cleanup patch" * tag 'for-linus-4.11-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xenbus: Remove duplicate inclusion of linux/init.h xen: do not re-use pirq number cached in pci device msi msg data
| * xenbus: Remove duplicate inclusion of linux/init.hMasanari Iida2017-02-271-1/+0
| | | | | | | | | | | | | | | | | | This patch remove duplicate inclusion of linux/init.h in xenbus_dev_frontend.c. Confirm successfully compile after remove the line. Signed-off-by: Masanari Iida <standby24x7@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com>
* | Merge branch 'stable/for-linus-4.11' of ↵Linus Torvalds2017-03-071-0/+47
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb updates from Konrad Rzeszutek Wilk: "Two tiny implementations of the DMA API for callback in ARM (for Xen)" * 'stable/for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb-xen: implement xen_swiotlb_get_sgtable callback swiotlb-xen: implement xen_swiotlb_dma_mmap callback
| * | swiotlb-xen: implement xen_swiotlb_get_sgtable callbackAndrii Anisov2017-02-131-0/+28
| | | | | | | | | | | | | | | | | | Signed-off-by: Andrii Anisov <andrii_anisov@epam.com> Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
| * | swiotlb-xen: implement xen_swiotlb_dma_mmap callbackStefano Stabellini2017-02-131-0/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | This function creates userspace mapping for the DMA-coherent memory. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Signed-off-by: Oleksandr Dmytryshyn <oleksandr.dmytryshyn@globallogic.com> Signed-off-by: Andrii Anisov <andrii_anisov@epam.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad@kernel.org>
* | | sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | sched/headers: Prepare for new header dependencies before moving code to ↵Ingo Molnar2017-03-021-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | <linux/sched/mm.h> We are going to split <linux/sched/mm.h> out of <linux/sched.h>, which will have to be picked up from other headers and a couple of .c files. Create a trivial placeholder <linux/sched/mm.h> file that just maps to <linux/sched.h> to make this patch obviously correct and bisectable. The APIs that are going to be moved first are: mm_alloc() __mmdrop() mmdrop() mmdrop_async_fn() mmdrop_async() mmget_not_zero() mmput() mmput_async() get_task_mm() mm_access() mm_release() Include the new header in the files that are going to need it. Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | mm, fs: reduce fault, page_mkwrite, and pfn_mkwrite to take only vmfDave Jiang2017-02-241-2/+2
| |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ->fault(), ->page_mkwrite(), and ->pfn_mkwrite() calls do not need to take a vma and vmf parameter when the vma already resides in vmf. Remove the vma parameter to simplify things. [arnd@arndb.de: fix ARM build] Link: http://lkml.kernel.org/r/20170125223558.1451224-1-arnd@arndb.de Link: http://lkml.kernel.org/r/148521301778.19116.10840599906674778980.stgit@djiang5-desk3.ch.intel.com Signed-off-by: Dave Jiang <dave.jiang@intel.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Theodore Ts'o <tytso@mit.edu> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: Matthew Wilcox <mawilcox@microsoft.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jan Kara <jack@suse.com> Cc: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | xen/privcmd: add IOCTL_PRIVCMD_RESTRICTPaul Durrant2017-02-141-9/+79
| | | | | | | | | | | | | | | | | | | | | | The purpose if this ioctl is to allow a user of privcmd to restrict its operation such that it will no longer service arbitrary hypercalls via IOCTL_PRIVCMD_HYPERCALL, and will check for a matching domid when servicing IOCTL_PRIVCMD_DM_OP or IOCTL_PRIVCMD_MMAP*. The aim of this is to limit the attack surface for a compromised device model. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen/privcmd: Add IOCTL_PRIVCMD_DM_OPPaul Durrant2017-02-141-0/+139
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recently a new dm_op[1] hypercall was added to Xen to provide a mechanism for restricting device emulators (such as QEMU) to a limited set of hypervisor operations, and being able to audit those operations in the kernel of the domain in which they run. This patch adds IOCTL_PRIVCMD_DM_OP as gateway for __HYPERVISOR_dm_op. NOTE: There is no requirement for user-space code to bounce data through locked memory buffers (as with IOCTL_PRIVCMD_HYPERCALL) since privcmd has enough information to lock the original buffers directly. [1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=524a98c2 Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Acked-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen/privcmd: return -ENOTTY for unimplemented IOCTLsPaul Durrant2017-02-131-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | The code sets the default return code to -ENOSYS but then overrides this to -EINVAL in the switch() statement's default case, which is clearly silly. This patch removes the override and sets the default return code to -ENOTTY, which is the conventional return for an unimplemented ioctl. Signed-off-by: Paul Durrant <paul.durrant@citrix.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen: optimize xenbus driver for multiple concurrent xenstore accessesJuergen Gross2017-02-094-391/+672
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handling of multiple concurrent Xenstore accesses through xenbus driver either from the kernel or user land is rather lame today: xenbus is capable to have one access active only at one point of time. Rewrite xenbus to handle multiple requests concurrently by making use of the request id of the Xenstore protocol. This requires to: - Instead of blocking inside xb_read() when trying to read data from the xenstore ring buffer do so only in the main loop of xenbus_thread(). - Instead of doing writes to the xenstore ring buffer in the context of the caller just queue the request and do the write in the dedicated xenbus thread. - Instead of just forwarding the request id specified by the caller of xenbus to xenstore use a xenbus internal unique request id. This will allow multiple outstanding requests. - Modify the locking scheme in order to allow multiple requests being active in parallel. - Instead of waiting for the reply of a user's xenstore request after writing the request to the xenstore ring buffer return directly to the caller and do the waiting in the read path. Additionally signal handling was optimized by avoiding waking up the xenbus thread or sending an event to Xenstore in case the addressed entity is known to be running already. As a result communication with Xenstore is sped up by a factor of up to 5: depending on the request type (read or write) and the amount of data transferred the gain was at least 20% (small reads) and went up to a factor of 5 for large writes. In the end some more rough edges of xenbus have been smoothed: - Handling of memory shortage when reading from xenstore ring buffer in the xenbus driver was not optimal: it was busy looping and issuing a warning in each loop. - In case of xenstore not running in dom0 but in a stubdom we end up with two xenbus threads running as the initialization of xenbus in dom0 expecting a local xenstored will be redone later when connecting to the xenstore domain. Up to now this was no problem as locking would prevent the two xenbus threads interfering with each other, but this was just a waste of kernel resources. - An out of memory situation while writing to or reading from the xenstore ring buffer no longer will lead to a possible loss of synchronization with xenstore. - The user read and write part are now interruptible by signals. Signed-off-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen: modify xenstore watch event interfaceJuergen Gross2017-02-0911-59/+49
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Today a Xenstore watch event is delivered via a callback function declared as: void (*callback)(struct xenbus_watch *, const char **vec, unsigned int len); As all watch events only ever come with two parameters (path and token) changing the prototype to: void (*callback)(struct xenbus_watch *, const char *path, const char *token); is the natural thing to do. Apply this change and adapt all users. Cc: konrad.wilk@oracle.com Cc: roger.pau@citrix.com Cc: wei.liu2@citrix.com Cc: paul.durrant@citrix.com Cc: netdev@vger.kernel.org Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Paul Durrant <paul.durrant@citrix.com> Reviewed-by: Wei Liu <wei.liu2@citrix.com> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen: clean up xenbus internal headersJuergen Gross2017-02-0912-93/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The xenbus driver has an awful mixture of internally and globally visible headers: some of the internally used only stuff is defined in the global header include/xen/xenbus.h while some stuff defined in internal headers is used by other drivers, too. Clean this up by moving the externally used symbols to include/xen/xenbus.h and the symbols used internally only to a new header drivers/xen/xenbus/xenbus.h replacing xenbus_comms.h and xenbus_probe.h Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xenbus: Neaten xenbus_va_dev_errorJoe Perches2017-02-081-29/+10
| | | | | | | | | | | | | | | | | | | | This function error patch can be simplified, so do so. Remove fail: label and somewhat obfuscating, used once "error_path" function. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | xen/pvh: Enable CPU hotplugBoris Ostrovsky2017-02-071-1/+1
| | | | | | | | | | | | | | | | PVH guests don't (yet) receive ACPI hotplug interrupts and therefore need to monitor xenstore for CPU hotplug event. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com>
* | xen/pvh: Initialize grant table for PVH guestsBoris Ostrovsky2017-02-071-4/+4
| | | | | | | | | | | | | | | | | | Like PV guests, PVH does not have PCI devices and therefore cannot use MMIO space to store grants. Instead it balloons out memory and keeps grants there. Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com>
* | xen/x86: Remove PVH supportBoris Ostrovsky2017-02-071-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | We are replacing existing PVH guests with new implementation. We are keeping xen_pvh_domain() macro (for now set to zero) because when we introduce new PVH implementation later in this series we will reuse current PVH-specific code (xen_pvh_gnttab_setup()), and that code is conditioned by 'if (xen_pvh_domain())'. (We will also need a noop xen_pvh_domain() for !CONFIG_XEN_PVH). Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Juergen Gross <jgross@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | xen/manage: correct return value check on xenbus_scanf()Jan Beulich2017-02-031-1/+1
| | | | | | | | | | | | | | | | | | A negative return value indicates an error; in fact the function at present won't ever return zero. Signed-off-by: Jan Beulich <jbeulich@suse.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | Merge branch 'stable/for-linus-4.10' of ↵Linus Torvalds2017-01-271-2/+3
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb fix from Konrad Rzeszutek Wilk: "An ARM fix in the Xen SWIOTLB - mainly the translation of physical to bus addresses was done just a tad too late" * 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb-xen: update dev_addr after swapping pages
| * | swiotlb-xen: update dev_addr after swapping pagesStefano Stabellini2017-01-201-2/+3
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In xen_swiotlb_map_page and xen_swiotlb_map_sg_attrs, if the original page is not suitable, we swap it for another page from the swiotlb pool. In these cases, we don't update the previously calculated dma address for the page before calling xen_dma_map_page. Thus, we end up calling xen_dma_map_page passing the wrong dev_addr, resulting in xen_dma_map_page mistakenly assuming that the page is foreign when it is local. Fix the bug by updating dev_addr appropriately. This change has no effect on x86, because xen_dma_map_page is a stub there. Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Signed-off-by: Pooya Keshavarzi <Pooya.Keshavarzi@de.bosch.com> Tested-by: Pooya Keshavarzi <Pooya.Keshavarzi@de.bosch.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | Merge tag 'for-linus-4.10-rc4-tag' of ↵Linus Torvalds2017-01-191-0/+71
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fix from Juergen Gross: "A fix for Xen running in nested virtualization environment" * tag 'for-linus-4.10-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: partially revert "xen: Remove event channel notification through Xen PCI platform device"
| * | partially revert "xen: Remove event channel notification through Xen PCI ↵Stefano Stabellini2017-01-131-0/+71
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | platform device" Commit 72a9b186292d ("xen: Remove event channel notification through Xen PCI platform device") broke Linux when booting as Dom0 on Xen in a nested Xen environment (Xen installed inside a Xen VM). In this scenario, Linux is a PV guest, but at the same time it uses the platform-pci driver to receive notifications from L0 Xen. vector callbacks are not available because L1 Xen doesn't allow them. Partially revert the offending commit, by restoring IRQ based notifications for PV guests only. I restored only the code which is strictly needed and replaced the xen_have_vector_callback checks within it with xen_pv_domain() checks. Signed-off-by: Stefano Stabellini <sstabellini@kernel.org> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
* | | Merge branch 'stable/for-linus-4.10' of ↵Linus Torvalds2017-01-061-2/+6
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb Pull swiotlb fixes from Konrad Rzeszutek Wilk: "This has one fix to make i915 work when using Xen SWIOTLB, and a feature from Geert to aid in debugging of devices that can't do DMA outside the 32-bit address space. The feature from Geert is on top of v4.10 merge window commit (specifically you pulling my previous branch), as his changes were dependent on the Documentation/ movement patches. I figured it would just easier than me trying than to cherry-pick the Documentation patches to satisfy git. The patches have been soaking since 12/20, albeit I updated the last patch due to linux-next catching an compiler error and adding an Tested-and-Reported-by tag" * 'stable/for-linus-4.10' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb: swiotlb: Export swiotlb_max_segment to users swiotlb: Add swiotlb=noforce debug option swiotlb: Convert swiotlb_force from int to enum x86, swiotlb: Simplify pci_swiotlb_detect_override()
| * | swiotlb: Export swiotlb_max_segment to usersKonrad Rzeszutek Wilk2017-01-061-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So they can figure out what is the optimal number of pages that can be contingously stitched together without fear of bounce buffer. We also expose an mechanism for sub-users of SWIOTLB API, such as Xen-SWIOTLB to set the max segment value. And lastly if swiotlb=force is set (which mandates we bounce buffer everything) we set max_segment so at least we can bounce buffer one 4K page instead of a giant 512KB one for which we may not have space. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-and-Tested-by: Juergen Gross <jgross@suse.com>
| * | swiotlb: Convert swiotlb_force from int to enumGeert Uytterhoeven2016-12-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | Convert the flag swiotlb_force from an int to an enum, to prepare for the advent of more possible values. Suggested-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
* | | Merge tag 'for-linus-4.10-rc2-tag' of ↵Linus Torvalds2017-01-055-29/+36
|\ \ \ | | |/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen fixes and cleanups from Juergen Gross: - small fixes for xenbus driver - one fix for xen dom0 boot on huge system - small cleanups * tag 'for-linus-4.10-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: Xen: ARM: Zero reserved fields of xatp before making hypervisor call xen: events: Replace BUG() with BUG_ON() xen: remove stale xs_input_avail() from header xen: return xenstore command failures via response instead of rc xen: xenbus driver must not accept invalid transaction ids xen/evtchn: use rb_entry() xen/setup: Don't relocate p2m over existing one
| * | Xen: ARM: Zero reserved fields of xatp before making hypervisor callJiandi An2017-01-031-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure all reserved fields of xatp are zero before making hypervisor call to XEN in xen_map_device_mmio(). xenmem_add_to_physmap_one() in XEN fails the mapping request if extra.res reserved field in xatp is not zero for XENMAPSPACE_dev_mmio request. Signed-off-by: Jiandi An <anjiandi@codeaurora.org> Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
| * | xen: events: Replace BUG() with BUG_ON()Shyam Saini2017-01-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | Replace BUG() with BUG_ON() using coccinelle Signed-off-by: Shyam Saini <mayhs11saini@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen: remove stale xs_input_avail() from headerJuergen Gross2016-12-231-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | In drivers/xen/xenbus/xenbus_comms.h there is a stale declaration of xs_input_avail(). Remove it. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen: return xenstore command failures via response instead of rcJuergen Gross2016-12-231-20/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the xenbus driver does some special handling for a Xenstore command any error condition related to the command should be returned via an error response instead of letting the related write operation fail. Otherwise the user land handler might take wrong decisions assuming the connection to Xenstore is broken. While at it try to return the same error values xenstored would return for those cases. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen: xenbus driver must not accept invalid transaction idsJuergen Gross2016-12-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When accessing Xenstore in a transaction the user is specifying a transaction id which he normally obtained from Xenstore when starting the transaction. Xenstore is validating a transaction id against all known transaction ids of the connection the request came in. As all requests of a domain not being the one where Xenstore lives share one connection, validation of transaction ids of different users of Xenstore in that domain should be done by the kernel of that domain being the multiplexer between the Xenstore users in that domain and Xenstore. In order to prohibit one Xenstore user "hijacking" a transaction from another user the xenbus driver has to verify a given transaction id against all known transaction ids of the user before forwarding it to Xenstore. Signed-off-by: Juergen Gross <jgross@suse.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * | xen/evtchn: use rb_entry()Geliang Tang2016-12-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | To make the code clearer, use rb_entry() instead of container_of() to deal with rbtree. Signed-off-by: Geliang Tang <geliangtang@gmail.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
* | | cpu/hotplug: Cleanup state namesThomas Gleixner2016-12-251-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the state names got added a script was used to add the extra argument to the calls. The script basically converted the state constant to a string, but the cleanup to convert these strings into meaningful ones did not happen. Replace all the useless strings with 'subsys/xxx/yyy:state' strings which are used in all the other places already. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sebastian Siewior <bigeasy@linutronix.de> Link: http://lkml.kernel.org/r/20161221192112.085444152@linutronix.de Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | mm: use vmf->address instead of of vmf->virtual_addressJan Kara2016-12-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Every single user of vmf->virtual_address typed that entry to unsigned long before doing anything with it so the type of virtual_address does not really provide us any additional safety. Just use masked vmf->address which already has the appropriate type. Link: http://lkml.kernel.org/r/1479460644-25076-3-git-send-email-jack@suse.cz Signed-off-by: Jan Kara <jack@suse.cz> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'for-linus-4.10-rc0-tag' of ↵Linus Torvalds2016-12-1310-32/+37
|\| | | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen updates from Juergen Gross: "Xen features and fixes for 4.10 These are some fixes, a move of some arm related headers to share them between arm and arm64 and a series introducing a helper to make code more readable. The most notable change is David stepping down as maintainer of the Xen hypervisor interface. This results in me sending you the pull requests for Xen related code from now on" * tag 'for-linus-4.10-rc0-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: (29 commits) xen/balloon: Only mark a page as managed when it is released xenbus: fix deadlock on writes to /proc/xen/xenbus xen/scsifront: don't request a slot on the ring until request is ready xen/x86: Increase xen_e820_map to E820_X_MAX possible entries x86: Make E820_X_MAX unconditionally larger than E820MAX xen/pci: Bubble up error and fix description. xen: xenbus: set error code on failure xen: set error code on failures arm/xen: Use alloc_percpu rather than __alloc_percpu arm/arm64: xen: Move shared architecture headers to include/xen/arm xen/events: use xen_vcpu_id mapping for EVTCHNOP_status xen/gntdev: Use VM_MIXEDMAP instead of VM_IO to avoid NUMA balancing xen-scsifront: Add a missing call to kfree MAINTAINERS: update XEN HYPERVISOR INTERFACE xenfs: Use proc_create_mount_point() to create /proc/xen xen-platform: use builtin_pci_driver xen-netback: fix error handling output xen: make use of xenbus_read_unsigned() in xenbus xen: make use of xenbus_read_unsigned() in xen-pciback xen: make use of xenbus_read_unsigned() in xen-fbfront ...
| * xen/balloon: Only mark a page as managed when it is releasedRoss Lagerwall2016-12-121-4/+2
| | | | | | | | | | | | | | | | | | | | | | Only mark a page as managed when it is released back to the allocator. This ensures that the managed page count does not get falsely increased when a VM is running. Correspondingly change it so that pages are marked as unmanaged after getting them from the allocator. Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * xenbus: fix deadlock on writes to /proc/xen/xenbusDavid Vrabel2016-12-121-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | /proc/xen/xenbus does not work correctly. A read blocked waiting for a xenstore message holds the mutex needed for atomic file position updates. This blocks any writes on the same file handle, which can deadlock if the write is needed to unblock the read. Clear FMODE_ATOMIC_POS when opening this device to always get character device like sematics. Signed-off-by: David Vrabel <david.vrabel@citrix.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
| * xen: xenbus: set error code on failurePan Bian2016-12-081-1/+1
| | | | | | | | | | | | | | | | | | | | Variable err is initialized with 0. As a result, the return value may be 0 even if get_zeroed_page() fails to allocate memory. This patch fixes the bug, initializing err with "-ENOMEM". Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Juergen Gross <jgross@suse.com> Signed-off-by: Juergen Gross <jgross@suse.com>
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-05 04:40:13 +0000