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2016-07-29ovl: dilute permission checks on lower only if not special fileVivek Goyal
Right now if file is on lower/, we remove MAY_WRITE/MAY_APPEND bits from mask as lower/ will never be written and file will be copied up. But this is not true for special files. These files are not copied up and are opened in place. So don't dilute the checks for these types of files. Reported-by: Dan Walsh <dwalsh@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: fix POSIX ACL settingMiklos Szeredi
Setting POSIX ACL needs special handling: 1) Some permission checks are done by ->setxattr() which now uses mounter's creds ("ovl: do operations on underlying file system in mounter's context"). These permission checks need to be done with current cred as well. 2) Setting ACL can fail for various reasons. We do not need to copy up in these cases. In the mean time switch to using generic_setxattr. [Arnd Bergmann] Fix link error without POSIX ACL. posix_acl_from_xattr() doesn't have a 'static inline' implementation when CONFIG_FS_POSIX_ACL is disabled, and I could not come up with an obvious way to do it. This instead avoids the link error by defining two sets of ACL operations and letting the compiler drop one of the two at compile time depending on CONFIG_FS_POSIX_ACL. This avoids all references to the ACL code, also leading to smaller code. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: share inode for hard linkMiklos Szeredi
Inode attributes are copied up to overlay inode (uid, gid, mode, atime, mtime, ctime) so generic code using these fields works correcty. If a hard link is created in overlayfs separate inodes are allocated for each link. If chmod/chown/etc. is performed on one of the links then the inode belonging to the other ones won't be updated. This patch attempts to fix this by sharing inodes for hard links. Use inode hash (with real inode pointer as a key) to make sure overlay inodes are shared for hard links on upper. Hard links on lower are still split (which is not user observable until the copy-up happens, see Documentation/filesystems/overlayfs.txt under "Non-standard behavior"). The inode is only inserted in the hash if it is non-directoy and upper. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: store real inode pointer in ->i_privateMiklos Szeredi
To get from overlay inode to real inode we currently use 'struct ovl_entry', which has lifetime connected to overlay dentry. This is okay, since each overlay dentry had a new overlay inode allocated. Following patch will break that assumption, so need to leave out ovl_entry. This patch stores the real inode directly in i_private, with the lowest bit used to indicate whether the inode is upper or lower. Lifetime rules remain, using ovl_inode_real() must only be done while caller holds ref on overlay dentry (and hence on real dentry), or within RCU protected regions. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: permission: return ECHILD instead of ENOENTMiklos Szeredi
The error is due to RCU and is temporary. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: update atime on upperMiklos Szeredi
Fix atime update logic in overlayfs. This patch adds an i_op->update_time() handler to overlayfs inodes. This forwards atime updates to the upper layer only. No atime updates are done on lower layers. Remove implicit atime updates to underlying files and directories with O_NOATIME. Remove explicit atime update in ovl_readlink(). Clear atime related mnt flags from cloned upper mount. This means atime updates are controlled purely by overlayfs mount options. Reported-by: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: fix sgid on directoryMiklos Szeredi
When creating directory in workdir, the group/sgid inheritance from the parent dir was omitted completely. Fix this by calling inode_init_owner() on overlay inode and using the resulting uid/gid/mode to create the file. Unfortunately the sgid bit can be stripped off due to umask, so need to reset the mode in this case in workdir before moving the directory in place. Reported-by: Eryu Guan <eguan@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: simplify permission checkingMiklos Szeredi
The fact that we always do permission checking on the overlay inode and clear MAY_WRITE for checking access to the lower inode allows cruft to be removed from ovl_permission(). 1) "default_permissions" option effectively did generic_permission() on the overlay inode with i_mode, i_uid and i_gid updated from underlying filesystem. This is what we do by default now. It did the update using vfs_getattr() but that's only needed if the underlying filesystem can change (which is not allowed). We may later introduce a "paranoia_mode" that verifies that mode/uid/gid are not changed. 2) splitting out the IS_RDONLY() check from inode_permission() also becomes unnecessary once we remove the MAY_WRITE from the lower inode check. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: do not require mounter to have MAY_WRITE on lowerVivek Goyal
Now we have two levels of checks in ovl_permission(). overlay inode is checked with the creds of task while underlying inode is checked with the creds of mounter. Looks like mounter does not have to have WRITE access to files on lower/. So remove the MAY_WRITE from access mask for checks on underlying lower inode. This means task should still have the MAY_WRITE permission on lower inode and mounter is not required to have MAY_WRITE. It also solves the problem of read only NFS mounts being used as lower. If __inode_permission(lower_inode, MAY_WRITE) is called on read only NFS, it fails. By resetting MAY_WRITE, check succeeds and case of read only NFS shold work with overlay without having to specify any special mount options (default permission). Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: do operations on underlying file system in mounter's contextVivek Goyal
Given we are now doing checks both on overlay inode as well underlying inode, we should be able to do checks and operations on underlying file system using mounter's context. So modify all operations to do checks/operations on underlying dentry/inode in the context of mounter. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: modify ovl_permission() to do checks on two inodesVivek Goyal
Right now ovl_permission() calls __inode_permission(realinode), to do permission checks on real inode and no checks are done on overlay inode. Modify it to do checks both on overlay inode as well as underlying inode. Checks on overlay inode will be done with the creds of calling task while checks on underlying inode will be done with the creds of mounter. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: define ->get_acl() for overlay inodesVivek Goyal
Now we are planning to do DAC permission checks on overlay inode itself. And to make it work, we will need to make sure we can get acls from underlying inode. So define ->get_acl() for overlay inodes and this in turn calls into underlying filesystem to get acls, if any. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: move some common code in a functionVivek Goyal
ovl_create_upper() and ovl_create_over_whiteout() seem to be sharing some common code which can be moved into a separate function. No functionality change. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: store ovl_entry in inode->i_private for all inodesAndreas Gruenbacher
Previously this was only done for directory inodes. Doing so for all inodes makes for a nice cleanup in ovl_permission at zero cost. Inodes are not shared for hard links on the overlay, so this works fine. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: use generic_delete_inodeMiklos Szeredi
No point in keeping overlay inodes around since they will never be reused. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: check mounter creds on underlying lookupMiklos Szeredi
The hash salting changes meant that we can no longer reuse the hash in the overlay dentry to look up the underlying dentry. Instead of lookup_hash(), use lookup_one_len_unlocked() and swith to mounter's creds (like we do for all other operations later in the series). Now the lookup_hash() export introduced in 4.6 by 3c9fe8cdff1b ("vfs: add lookup_hash() helper") is unused and can possibly be removed; its usefulness negated by the hash salting and the idea that mounter's creds should be used on operations on underlying filesystems. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 8387ff2577eb ("vfs: make the string hashes salt the hash")
2016-07-29avr32: off by one in at32_init_pio()Dan Carpenter
The pio_dev[] array has MAX_NR_PIO_DEVICES elements so the > should be >=. Fixes: 5f97f7f9400d ('[PATCH] avr32 architecture') Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
2016-07-29avr32: fixup code style in unistd.h and syscall_table.SHans-Christian Noren Egtvedt
This patch swaps the mix of tabs and space for alignment of comment after code to use spaces only. Also document why recvmmsg was defined twice in the syscall_table.S table, but only once in unistd.h. In short, wired in the table by generic arch patch, but forgotten in unistd.h (review slip).
2016-07-29avr32: wire up preadv2 and pwritev2 syscallsHans-Christian Noren Egtvedt
This patch wires up the new preadv2 and pwritev2 syscall on AVR32. On AVR32, all parameters beyond the 5th are passed on the stack. System calls don't use the stack -- they borrow a callee-saved register instead. This means that syscalls that take 6 parameters must be called through a stub that pushes the last parameter on the stack. Signed-off-by: Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>
2016-07-28sparc64 mm: Fix base TSB sizing when hugetlb pages are usedMike Kravetz
do_sparc64_fault() calculates both the base and huge page RSS sizes and uses this information in calls to tsb_grow(). The calculation for base page TSB size is not correct if the task uses hugetlb pages. hugetlb pages are not accounted for in RSS, therefore the call to get_mm_rss(mm) does not include hugetlb pages. However, the number of pages based on huge_pte_count (which does include hugetlb pages) is subtracted from this value. This will result in an artificially small and often negative RSS calculation. The base TSB size is then often set to max_tsb_size as the passed RSS is unsigned, so a negative value looks really big. THP pages are also accounted for in huge_pte_count, and THP pages are accounted for in RSS so the calculation in do_sparc64_fault() is correct if a task only uses THP pages. A single huge_pte_count is not sufficient for TSB sizing if both hugetlb and THP pages can be used. Instead of a single counter, use two: one for hugetlb and one for THP. Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2016-07-28Merge tag 'trace-v4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing updates from Steven Rostedt: "This is mostly clean ups and small fixes. Some of the more visible changes are: - The function pid code uses the event pid filtering logic - [ku]probe events have access to current->comm - trace_printk now has sample code - PCI devices now trace physical addresses - stack tracing has less unnessary functions traced" * tag 'trace-v4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: printk, tracing: Avoiding unneeded blank lines tracing: Use __get_str() when manipulating strings tracing, RAS: Cleanup on __get_str() usage tracing: Use outer () on __get_str() definition ftrace: Reduce size of function graph entries tracing: Have HIST_TRIGGERS select TRACING tracing: Using for_each_set_bit() to simplify trace_pid_write() ftrace: Move toplevel init out of ftrace_init_tracefs() tracing/function_graph: Fix filters for function_graph threshold tracing: Skip more functions when doing stack tracing of events tracing: Expose CPU physical addresses (resource values) for PCI devices tracing: Show the preempt count of when the event was called tracing: Add trace_printk sample code tracing: Choose static tp_printk buffer by explicit nesting count tracing: expose current->comm to [ku]probe events ftrace: Have set_ftrace_pid use the bitmap like events do tracing: Move pid_list write processing into its own function tracing: Move the pid_list seq_file functions to be global tracing: Move filtered_pid helper functions into trace.c tracing: Make the pid filtering helper functions global
2016-07-28Merge tag 'vfio-v4.8-rc1' of git://github.com/awilliam/linux-vfioLinus Torvalds
Pull VFIO updates from Alex Williamson: - Enable no-iommu mode for platform devices (Peng Fan) - Sub-page mmap for exclusive pages (Yongji Xie) - Use-after-free fix (Ilya Lesokhin) - Support for ACPI-based platform devices (Sinan Kaya) * tag 'vfio-v4.8-rc1' of git://github.com/awilliam/linux-vfio: vfio: platform: check reset call return code during release vfio: platform: check reset call return code during open vfio, platform: make reset driver a requirement by default vfio: platform: call _RST method when using ACPI vfio: platform: add extra debug info argument to call reset vfio: platform: add support for ACPI probe vfio: platform: determine reset capability vfio: platform: move reset call to a common function vfio: platform: rename reset function vfio: fix possible use after free of vfio group vfio-pci: Allow to mmap sub-page MMIO BARs if the mmio page is exclusive vfio: platform: support No-IOMMU mode
2016-07-28Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/shli/md Pull MD updates from Shaohua Li: - A bunch of patches from Neil Brown to fix RCU usage - Two performance improvement patches from Tomasz Majchrzak - Alexey Obitotskiy fixes module refcount issue - Arnd Bergmann fixes time granularity - Cong Wang fixes a list corruption issue - Guoqing Jiang fixes a deadlock in md-cluster - A null pointer deference fix from me - Song Liu fixes misuse of raid6 rmw - Other trival/cleanup fixes from Guoqing Jiang and Xiao Ni * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/shli/md: (28 commits) MD: fix null pointer deference raid10: improve random reads performance md: add missing sysfs_notify on array_state update Fix kernel module refcount handling md: use seconds granularity for error logging md: reduce the number of synchronize_rcu() calls when multiple devices fail. md: be extra careful not to take a reference to a Faulty device. md/multipath: add rcu protection to rdev access in multipath_status. md/raid5: add rcu protection to rdev accesses in raid5_status. md/raid5: add rcu protection to rdev accesses in want_replace md/raid5: add rcu protection to rdev accesses in handle_failed_sync. md/raid1: add rcu protection to rdev in fix_read_error md/raid1: small code cleanup in end_sync_write md/raid1: small cleanup in raid1_end_read/write_request md/raid10: simplify print_conf a little. md/raid10: minor code improvement in fix_read_error() md/raid10: add rcu protection to rdev access during reshape. md/raid10: add rcu protection to rdev access in raid10_sync_request. md/raid10: add rcu protection in raid10_status. md/raid10: fix refounct imbalance when resyncing an array with a replacement device. ...
2016-07-28Merge tag 'libnvdimm-for-4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: - Replace pcommit with ADR / directed-flushing. The pcommit instruction, which has not shipped on any product, is deprecated. Instead, the requirement is that platforms implement either ADR, or provide one or more flush addresses per nvdimm. ADR (Asynchronous DRAM Refresh) flushes data in posted write buffers to the memory controller on a power-fail event. Flush addresses are defined in ACPI 6.x as an NVDIMM Firmware Interface Table (NFIT) sub-structure: "Flush Hint Address Structure". A flush hint is an mmio address that when written and fenced assures that all previous posted writes targeting a given dimm have been flushed to media. - On-demand ARS (address range scrub). Linux uses the results of the ACPI ARS commands to track bad blocks in pmem devices. When latent errors are detected we re-scrub the media to refresh the bad block list, userspace can also request a re-scrub at any time. - Support for the Microsoft DSM (device specific method) command format. - Support for EDK2/OVMF virtual disk device memory ranges. - Various fixes and cleanups across the subsystem. * tag 'libnvdimm-for-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (41 commits) libnvdimm-btt: Delete an unnecessary check before the function call "__nd_device_register" nfit: do an ARS scrub on hitting a latent media error nfit: move to nfit/ sub-directory nfit, libnvdimm: allow an ARS scrub to be triggered on demand libnvdimm: register nvdimm_bus devices with an nd_bus driver pmem: clarify a debug print in pmem_clear_poison x86/insn: remove pcommit Revert "KVM: x86: add pcommit support" nfit, tools/testing/nvdimm/: unify shutdown paths libnvdimm: move ->module to struct nvdimm_bus_descriptor nfit: cleanup acpi_nfit_init calling convention nfit: fix _FIT evaluation memory leak + use after free tools/testing/nvdimm: add manufacturing_{date|location} dimm properties tools/testing/nvdimm: add virtual ramdisk range acpi, nfit: treat virtual ramdisk SPA as pmem region pmem: kill __pmem address space pmem: kill wmb_pmem() libnvdimm, pmem: use nvdimm_flush() for namespace I/O writes fs/dax: remove wmb_pmem() libnvdimm, pmem: flush posted-write queues on shutdown ...
2016-07-28Merge tag 'pinctrl-v4.8-1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl Pull pin control updates from Linus Walleij: "This is the bulk of pin control changes for the v4.8 kernel cycle. Nothing stands out as especially exiting: new drivers, new subdrivers, lots of cleanups and incremental features. Business as usual. New drivers: - New driver for Oxnas pin control and GPIO. This ARM-based chipset is used in a few storage (NAS) type devices. - New driver for the MAX77620/MAX20024 pin controller portions. - New driver for the Intel Merrifield pin controller. New subdrivers: - New subdriver for the Qualcomm MDM9615 - New subdriver for the STM32F746 MCU - New subdriver for the Broadcom NSP SoC. Cleanups: - Demodularization of bool compiled-in drivers. Apart from this there is just regular incremental improvements to a lot of drivers, especially Uniphier and PFC" * tag 'pinctrl-v4.8-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (131 commits) pinctrl: fix pincontrol definition for marvell pinctrl: xway: fix typo Revert "pinctrl: amd: make it explicitly non-modular" pinctrl: iproc: Add NSP and Stingray GPIO support pinctrl: Update iProc GPIO DT bindings pinctrl: bcm: add OF dependencies pinctrl: ns2: remove redundant dev_err call in ns2_pinmux_probe() pinctrl: Add STM32F746 MCU support pinctrl: intel: Protect set wake flow by spin lock pinctrl: nsp: remove redundant dev_err call in nsp_pinmux_probe() pinctrl: uniphier: add Ethernet pin-mux settings sh-pfc: Use PTR_ERR_OR_ZERO() to simplify the code pinctrl: ns2: fix return value check in ns2_pinmux_probe() pinctrl: qcom: update DT bindings with ebi2 groups pinctrl: qcom: establish proper EBI2 pin groups pinctrl: imx21: Remove the MODULE_DEVICE_TABLE() macro Documentation: dt: Add new compatible to STM32 pinctrl driver bindings includes: dt-bindings: Add STM32F746 pinctrl DT bindings pinctrl: sunxi: fix nand0 function name for sun8i pinctrl: uniphier: remove pointless pin-mux settings for PH1-LD11 ...
2016-07-28Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge more updates from Andrew Morton: "The rest of MM" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (101 commits) mm, compaction: simplify contended compaction handling mm, compaction: introduce direct compaction priority mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocations mm, page_alloc: make THP-specific decisions more generic mm, page_alloc: restructure direct compaction handling in slowpath mm, page_alloc: don't retry initial attempt in slowpath mm, page_alloc: set alloc_flags only once in slowpath lib/stackdepot.c: use __GFP_NOWARN for stack allocations mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUB mm, kasan: account for object redzone in SLUB's nearest_obj() mm: fix use-after-free if memory allocation failed in vma_adjust() zsmalloc: Delete an unnecessary check before the function call "iput" mm/memblock.c: fix index adjustment error in __next_mem_range_rev() mem-hotplug: alloc new page from a nearest neighbor node when mem-offline mm: optimize copy_page_to/from_iter_iovec mm: add cond_resched() to generic_swapfile_activate() Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements" mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT mode mm: hwpoison: remove incorrect comments make __section_nr() more efficient ...
2016-07-28mm, compaction: simplify contended compaction handlingVlastimil Babka
Async compaction detects contention either due to failing trylock on zone->lock or lru_lock, or by need_resched(). Since 1f9efdef4f3f ("mm, compaction: khugepaged should not give up due to need_resched()") the code got quite complicated to distinguish these two up to the __alloc_pages_slowpath() level, so different decisions could be taken for khugepaged allocations. After the recent changes, khugepaged allocations don't check for contended compaction anymore, so we again don't need to distinguish lock and sched contention, and simplify the current convoluted code a lot. However, I believe it's also possible to simplify even more and completely remove the check for contended compaction after the initial async compaction for costly orders, which was originally aimed at THP page fault allocations. There are several reasons why this can be done now: - with the new defaults, THP page faults no longer do reclaim/compaction at all, unless the system admin has overridden the default, or application has indicated via madvise that it can benefit from THP's. In both cases, it means that the potential extra latency is expected and worth the benefits. - even if reclaim/compaction proceeds after this patch where it previously wouldn't, the second compaction attempt is still async and will detect the contention and back off, if the contention persists - there are still heuristics like deferred compaction and pageblock skip bits in place that prevent excessive THP page fault latencies Link: http://lkml.kernel.org/r/20160721073614.24395-9-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, compaction: introduce direct compaction priorityVlastimil Babka
In the context of direct compaction, for some types of allocations we would like the compaction to either succeed or definitely fail while trying as hard as possible. Current async/sync_light migration mode is insufficient, as there are heuristics such as caching scanner positions, marking pageblocks as unsuitable or deferring compaction for a zone. At least the final compaction attempt should be able to override these heuristics. To communicate how hard compaction should try, we replace migration mode with a new enum compact_priority and change the relevant function signatures. In compact_zone_order() where struct compact_control is constructed, the priority is mapped to suitable control flags. This patch itself has no functional change, as the current priority levels are mapped back to the same migration modes as before. Expanding them will be done next. Note that !CONFIG_COMPACTION variant of try_to_compact_pages() is removed, as the only caller exists under CONFIG_COMPACTION. Link: http://lkml.kernel.org/r/20160721073614.24395-8-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, thp: remove __GFP_NORETRY from khugepaged and madvised allocationsVlastimil Babka
After the previous patch, we can distinguish costly allocations that should be really lightweight, such as THP page faults, with __GFP_NORETRY. This means we don't need to recognize khugepaged allocations via PF_KTHREAD anymore. We can also change THP page faults in areas where madvise(MADV_HUGEPAGE) was used to try as hard as khugepaged, as the process has indicated that it benefits from THP's and is willing to pay some initial latency costs. We can also make the flags handling less cryptic by distinguishing GFP_TRANSHUGE_LIGHT (no reclaim at all, default mode in page fault) from GFP_TRANSHUGE (only direct reclaim, khugepaged default). Adding __GFP_NORETRY or __GFP_KSWAPD_RECLAIM is done where needed. The patch effectively changes the current GFP_TRANSHUGE users as follows: * get_huge_zero_page() - the zero page lifetime should be relatively long and it's shared by multiple users, so it's worth spending some effort on it. We use GFP_TRANSHUGE, and __GFP_NORETRY is not added. This also restores direct reclaim to this allocation, which was unintentionally removed by commit e4a49efe4e7e ("mm: thp: set THP defrag by default to madvise and add a stall-free defrag option") * alloc_hugepage_khugepaged_gfpmask() - this is khugepaged, so latency is not an issue. So if khugepaged "defrag" is enabled (the default), do reclaim via GFP_TRANSHUGE without __GFP_NORETRY. We can remove the PF_KTHREAD check from page alloc. As a side-effect, khugepaged will now no longer check if the initial compaction was deferred or contended. This is OK, as khugepaged sleep times between collapsion attempts are long enough to prevent noticeable disruption, so we should allow it to spend some effort. * migrate_misplaced_transhuge_page() - already was masking out __GFP_RECLAIM, so just convert to GFP_TRANSHUGE_LIGHT which is equivalent. * alloc_hugepage_direct_gfpmask() - vma's with VM_HUGEPAGE (via madvise) are now allocating without __GFP_NORETRY. Other vma's keep using __GFP_NORETRY if direct reclaim/compaction is at all allowed (by default it's allowed only for madvised vma's). The rest is conversion to GFP_TRANSHUGE(_LIGHT). [mhocko@suse.com: suggested GFP_TRANSHUGE_LIGHT] Link: http://lkml.kernel.org/r/20160721073614.24395-7-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, page_alloc: make THP-specific decisions more genericVlastimil Babka
Since THP allocations during page faults can be costly, extra decisions are employed for them to avoid excessive reclaim and compaction, if the initial compaction doesn't look promising. The detection has never been perfect as there is no gfp flag specific to THP allocations. At this moment it checks the whole combination of flags that makes up GFP_TRANSHUGE, and hopes that no other users of such combination exist, or would mind being treated the same way. Extra care is also taken to separate allocations from khugepaged, where latency doesn't matter that much. It is however possible to distinguish these allocations in a simpler and more reliable way. The key observation is that after the initial compaction followed by the first iteration of "standard" reclaim/compaction, both __GFP_NORETRY allocations and costly allocations without __GFP_REPEAT are declared as failures: /* Do not loop if specifically requested */ if (gfp_mask & __GFP_NORETRY) goto nopage; /* * Do not retry costly high order allocations unless they are * __GFP_REPEAT */ if (order > PAGE_ALLOC_COSTLY_ORDER && !(gfp_mask & __GFP_REPEAT)) goto nopage; This means we can further distinguish allocations that are costly order *and* additionally include the __GFP_NORETRY flag. As it happens, GFP_TRANSHUGE allocations do already fall into this category. This will also allow other costly allocations with similar high-order benefit vs latency considerations to use this semantic. Furthermore, we can distinguish THP allocations that should try a bit harder (such as from khugepageed) by removing __GFP_NORETRY, as will be done in the next patch. Link: http://lkml.kernel.org/r/20160721073614.24395-6-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, page_alloc: restructure direct compaction handling in slowpathVlastimil Babka
The retry loop in __alloc_pages_slowpath is supposed to keep trying reclaim and compaction (and OOM), until either the allocation succeeds, or returns with failure. Success here is more probable when reclaim precedes compaction, as certain watermarks have to be met for compaction to even try, and more free pages increase the probability of compaction success. On the other hand, starting with light async compaction (if the watermarks allow it), can be more efficient, especially for smaller orders, if there's enough free memory which is just fragmented. Thus, the current code starts with compaction before reclaim, and to make sure that the last reclaim is always followed by a final compaction, there's another direct compaction call at the end of the loop. This makes the code hard to follow and adds some duplicated handling of migration_mode decisions. It's also somewhat inefficient that even if reclaim or compaction decides not to retry, the final compaction is still attempted. Some gfp flags combination also shortcut these retry decisions by "goto noretry;", making it even harder to follow. This patch attempts to restructure the code with only minimal functional changes. The call to the first compaction and THP-specific checks are now placed above the retry loop, and the "noretry" direct compaction is removed. The initial compaction is additionally restricted only to costly orders, as we can expect smaller orders to be held back by watermarks, and only larger orders to suffer primarily from fragmentation. This better matches the checks in reclaim's shrink_zones(). There are two other smaller functional changes. One is that the upgrade from async migration to light sync migration will always occur after the initial compaction. This is how it has been until recent patch "mm, oom: protect !costly allocations some more", which introduced upgrading the mode based on COMPACT_COMPLETE result, but kept the final compaction always upgraded, which made it even more special. It's better to return to the simpler handling for now, as migration modes will be further modified later in the series. The second change is that once both reclaim and compaction declare it's not worth to retry the reclaim/compact loop, there is no final compaction attempt. As argued above, this is intentional. If that final compaction were to succeed, it would be due to a wrong retry decision, or simply a race with somebody else freeing memory for us. The main outcome of this patch should be simpler code. Logically, the initial compaction without reclaim is the exceptional case to the reclaim/compaction scheme, but prior to the patch, it was the last loop iteration that was exceptional. Now the code matches the logic better. The change also enable the following patches. Link: http://lkml.kernel.org/r/20160721073614.24395-5-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, page_alloc: don't retry initial attempt in slowpathVlastimil Babka
After __alloc_pages_slowpath() sets up new alloc_flags and wakes up kswapd, it first tries get_page_from_freelist() with the new alloc_flags, as it may succeed e.g. due to using min watermark instead of low watermark. It makes sense to to do this attempt before adjusting zonelist based on alloc_flags/gfp_mask, as it's still relatively a fast path if we just wake up kswapd and successfully allocate. This patch therefore moves the initial attempt above the retry label and reorganizes a bit the part below the retry label. We still have to attempt get_page_from_freelist() on each retry, as some allocations cannot do that as part of direct reclaim or compaction, and yet are not allowed to fail (even though they do a WARN_ON_ONCE() and thus should not exist). We can reuse the call meant for ALLOC_NO_WATERMARKS attempt and just set alloc_flags to ALLOC_NO_WATERMARKS if the context allows it. As a side-effect, the attempts from direct reclaim/compaction will also no longer obey watermarks once this is set, but there's little harm in that. Kswapd wakeups are also done on each retry to be safe from potential races resulting in kswapd going to sleep while a process (that may not be able to reclaim by itself) is still looping. Link: http://lkml.kernel.org/r/20160721073614.24395-4-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, page_alloc: set alloc_flags only once in slowpathVlastimil Babka
In __alloc_pages_slowpath(), alloc_flags doesn't change after it's initialized, so move the initialization above the retry: label. Also make the comment above the initialization more descriptive. The only exception in the alloc_flags being constant is ALLOC_NO_WATERMARKS, which may change due to TIF_MEMDIE being set on the allocating thread. We can fix this, and make the code simpler and a bit more effective at the same time, by moving the part that determines ALLOC_NO_WATERMARKS from gfp_to_alloc_flags() to gfp_pfmemalloc_allowed(). This means we don't have to mask out ALLOC_NO_WATERMARKS in numerous places in __alloc_pages_slowpath() anymore. The only two tests for the flag can instead call gfp_pfmemalloc_allowed(). Link: http://lkml.kernel.org/r/20160721073614.24395-3-vbabka@suse.cz Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28lib/stackdepot.c: use __GFP_NOWARN for stack allocationsKirill A. Shutemov
This (large, atomic) allocation attempt can fail. We expect and handle that, so avoid the scary warning. Link: http://lkml.kernel.org/r/20160720151905.GB19146@node.shutemov.name Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Alexander Potapenko <glider@google.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Rik van Riel <riel@redhat.com> Cc: David Rientjes <rientjes@google.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>
2016-07-28mm, kasan: switch SLUB to stackdepot, enable memory quarantine for SLUBAlexander Potapenko
For KASAN builds: - switch SLUB allocator to using stackdepot instead of storing the allocation/deallocation stacks in the objects; - change the freelist hook so that parts of the freelist can be put into the quarantine. [aryabinin@virtuozzo.com: fixes] Link: http://lkml.kernel.org/r/1468601423-28676-1-git-send-email-aryabinin@virtuozzo.com Link: http://lkml.kernel.org/r/1468347165-41906-3-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, kasan: account for object redzone in SLUB's nearest_obj()Alexander Potapenko
When looking up the nearest SLUB object for a given address, correctly calculate its offset if SLAB_RED_ZONE is enabled for that cache. Previously, when KASAN had detected an error on an object from a cache with SLAB_RED_ZONE set, the actual start address of the object was miscalculated, which led to random stacks having been reported. When looking up the nearest SLUB object for a given address, correctly calculate its offset if SLAB_RED_ZONE is enabled for that cache. Fixes: 7ed2f9e663854db ("mm, kasan: SLAB support") Link: http://lkml.kernel.org/r/1468347165-41906-2-git-send-email-glider@google.com Signed-off-by: Alexander Potapenko <glider@google.com> Cc: Andrey Konovalov <adech.fo@gmail.com> Cc: Christoph Lameter <cl@linux.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Steven Rostedt (Red Hat) <rostedt@goodmis.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Kostya Serebryany <kcc@google.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Kuthonuzo Luruo <kuthonuzo.luruo@hpe.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm: fix use-after-free if memory allocation failed in vma_adjust()Kirill A. Shutemov
There's one case when vma_adjust() expands the vma, overlapping with *two* next vma. See case 6 of mprotect, described in the comment to vma_merge(). To handle this (and only this) situation we iterate twice over main part of the function. See "goto again". Vegard reported[1] that he sees out-of-bounds access complain from KASAN, if anon_vma_clone() on the *second* iteration fails. This happens because we free 'next' vma by the end of first iteration and don't have a way to undo this if anon_vma_clone() fails on the second iteration. The solution is to do all required allocations upfront, before we touch vmas. The allocation on the second iteration is only required if first two vmas don't have anon_vma, but third does. So we need, in total, one anon_vma_clone() call. It's easy to adjust 'exporter' to the third vma for such case. [1] http://lkml.kernel.org/r/1469514843-23778-1-git-send-email-vegard.nossum@oracle.com Link: http://lkml.kernel.org/r/1469625255-126641-1-git-send-email-kirill.shutemov@linux.intel.com Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Reported-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28zsmalloc: Delete an unnecessary check before the function call "iput"Markus Elfring
iput() tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Link: http://lkml.kernel.org/r/559cf499-4a01-25f9-c87f-24d906626a57@users.sourceforge.net Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Acked-by: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm/memblock.c: fix index adjustment error in __next_mem_range_rev()zijun_hu
Fix region index adjustment error when parameter type_b of __next_mem_range_rev() == NULL. Signed-off-by: zijun_hu <zijun_hu@htc.com> Cc: Alexander Kuleshov <kuleshovmail@gmail.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Wei Yang <weiyang@linux.vnet.ibm.com> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Richard Leitner <dev@g0hl1n.net> Cc: David Gibson <david@gibson.dropbear.id.au> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mem-hotplug: alloc new page from a nearest neighbor node when mem-offlineXishi Qiu
If we offline a node, alloc the new page from a nearest neighbor node instead of the current node or other remote nodes, because re-migrate is a waste of time and the distance of the remote nodes is often very large. Also use GFP_HIGHUSER_MOVABLE to alloc new page if the zone is movable zone or highmem zone. Link: http://lkml.kernel.org/r/5795E18B.5060302@huawei.com Signed-off-by: Xishi Qiu <qiuxishi@huawei.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm: optimize copy_page_to/from_iter_iovecMikulas Patocka
copy_page_to_iter_iovec() and copy_page_from_iter_iovec() copy some data to userspace or from userspace. These functions have a fast path where they map a page using kmap_atomic and a slow path where they use kmap. kmap is slower than kmap_atomic, so the fast path is preferred. However, on kernels without highmem support, kmap just calls page_address, so there is no need to avoid kmap. On kernels without highmem support, the fast path just increases code size (and cache footprint) and it doesn't improve copy performance in any way. This patch enables the fast path only if CONFIG_HIGHMEM is defined. Code size reduced by this patch: x86 (without highmem) 928 x86-64 960 sparc64 848 alpha 1136 pa-risc 1200 [akpm@linux-foundation.org: use IS_ENABLED(), per Andi] Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1607221711410.4818@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Andi Kleen <andi@firstfloor.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm: add cond_resched() to generic_swapfile_activate()Mikulas Patocka
generic_swapfile_activate() can take quite long time, it iterates over all blocks of a file, so add cond_resched to it. I observed about 1 second stalls when activating a swapfile that was almost unfragmented - this patch fixes it. Link: http://lkml.kernel.org/r/alpine.LRH.2.02.1607221710580.4818@file01.intranet.prod.int.rdu2.redhat.com Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Hugh Dickins <hughd@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Mel Gorman <mgorman@suse.de> Cc: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28Revert "mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"Michal Hocko
This reverts commit f9054c70d28b ("mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"). There has been a report about OOM killer invoked when swapping out to a dm-crypt device. The primary reason seems to be that the swapout out IO managed to completely deplete memory reserves. Ondrej was able to bisect and explained the issue by pointing to f9054c70d28b ("mm, mempool: only set __GFP_NOMEMALLOC if there are free elements"). The reason is that the swapout path is not throttled properly because the md-raid layer needs to allocate from the generic_make_request path which means it allocates from the PF_MEMALLOC context. dm layer uses mempool_alloc in order to guarantee a forward progress which used to inhibit access to memory reserves when using page allocator. This has changed by f9054c70d28b ("mm, mempool: only set __GFP_NOMEMALLOC if there are free elements") which has dropped the __GFP_NOMEMALLOC protection when the memory pool is depleted. If we are running out of memory and the only way forward to free memory is to perform swapout we just keep consuming memory reserves rather than throttling the mempool allocations and allowing the pending IO to complete up to a moment when the memory is depleted completely and there is no way forward but invoking the OOM killer. This is less than optimal. The original intention of f9054c70d28b was to help with the OOM situations where the oom victim depends on mempool allocation to make a forward progress. David has mentioned the following backtrace: schedule schedule_timeout io_schedule_timeout mempool_alloc __split_and_process_bio dm_request generic_make_request submit_bio mpage_readpages ext4_readpages __do_page_cache_readahead ra_submit filemap_fault handle_mm_fault __do_page_fault do_page_fault page_fault We do not know more about why the mempool is depleted without being replenished in time, though. In any case the dm layer shouldn't depend on any allocations outside of the dedicated pools so a forward progress should be guaranteed. If this is not the case then the dm should be fixed rather than papering over the problem and postponing it to later by accessing more memory reserves. mempools are a mechanism to maintain dedicated memory reserves to guaratee forward progress. Allowing them an unbounded access to the page allocator memory reserves is going against the whole purpose of this mechanism. Bisected by Ondrej Kozina. [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20160721145309.GR26379@dhcp22.suse.cz Signed-off-by: Michal Hocko <mhocko@suse.com> Reported-by: Ondrej Kozina <okozina@redhat.com> Reviewed-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: NeilBrown <neilb@suse.com> Cc: David Rientjes <rientjes@google.com> Cc: Mikulas Patocka <mpatocka@redhat.com> Cc: Ondrej Kozina <okozina@redhat.com> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Cc: Mel Gorman <mgorman@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm, compaction: don't isolate PageWriteback pages in MIGRATE_SYNC_LIGHT modeHugh Dickins
At present MIGRATE_SYNC_LIGHT is allowing __isolate_lru_page() to isolate a PageWriteback page, which __unmap_and_move() then rejects with -EBUSY: of course the writeback might complete in between, but that's not what we usually expect, so probably better not to isolate it. When tested by stress-highalloc from mmtests, this has reduced the number of page migrate failures by 60-70%. Link: http://lkml.kernel.org/r/20160721073614.24395-2-vbabka@suse.cz Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Mel Gorman <mgorman@techsingularity.net> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm: hwpoison: remove incorrect commentsNaoya Horiguchi
dequeue_hwpoisoned_huge_page() can be called without page lock hold, so let's remove incorrect comment. The reason why the page lock is not really needed is that dequeue_hwpoisoned_huge_page() checks page_huge_active() inside hugetlb_lock, which allows us to avoid trying to dequeue a hugepage that are just allocated but not linked to active list yet, even without taking page lock. Link: http://lkml.kernel.org/r/20160720092901.GA15995@www9186uo.sakura.ne.jp Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: Zhan Chen <zhanc1@andrew.cmu.edu> Acked-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28make __section_nr() more efficientZhou Chengming
When CONFIG_SPARSEMEM_EXTREME is disabled, __section_nr can get the section number with a subtraction directly. Link: http://lkml.kernel.org/r/1468988310-11560-1-git-send-email-zhouchengming1@huawei.com Signed-off-by: Zhou Chengming <zhouchengming1@huawei.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Hanjun Guo <guohanjun@huawei.com> Cc: Li Bin <huawei.libin@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28kmemleak: don't hang if user disables scanning earlyVegard Nossum
If the user tries to disable automatic scanning early in the boot process using e.g.: echo scan=off > /sys/kernel/debug/kmemleak then this command will hang until SECS_FIRST_SCAN (= 60) seconds have elapsed, even though the system is fully initialised. We can fix this using interruptible sleep and checking if we're supposed to stop whenever we wake up (like the rest of the code does). Link: http://lkml.kernel.org/r/1468835005-2873-1-git-send-email-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28arm64:acpi: fix the acpi alignment exception when 'mem=' specifiedDennis Chen
When booting an ACPI enabled kernel with 'mem=x', there is the possibility that ACPI data regions from the firmware will lie above the memory limit. Ordinarily these will be removed by memblock_enforce_memory_limit(.). Unfortunately, this means that these regions will then be mapped by acpi_os_ioremap(.) as device memory (instead of normal) thus unaligned accessess will then provoke alignment faults. In this patch we adopt memblock_mem_limit_remove_map instead, and this preserves these ACPI data regions (marked NOMAP) thus ensuring that these regions are not mapped as device memory. For example, below is an alignment exception observed on ARM platform when booting the kernel with 'acpi=on mem=8G': ... Unable to handle kernel paging request at virtual address ffff0000080521e7 pgd = ffff000008aa0000 [ffff0000080521e7] *pgd=000000801fffe003, *pud=000000801fffd003, *pmd=000000801fffc003, *pte=00e80083ff1c1707 Internal error: Oops: 96000021 [#1] PREEMPT SMP Modules linked in: CPU: 1 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc3-next-20160616+ #172 Hardware name: AMD Overdrive/Supercharger/Default string, BIOS ROD1001A 02/09/2016 task: ffff800001ef0000 ti: ffff800001ef8000 task.ti: ffff800001ef8000 PC is at acpi_ns_lookup+0x520/0x734 LR is at acpi_ns_lookup+0x4a4/0x734 pc : [<ffff0000083b8b10>] lr : [<ffff0000083b8a94>] pstate: 60000045 sp : ffff800001efb8b0 x29: ffff800001efb8c0 x28: 000000000000001b x27: 0000000000000001 x26: 0000000000000000 x25: ffff800001efb9e8 x24: ffff000008a10000 x23: 0000000000000001 x22: 0000000000000001 x21: ffff000008724000 x20: 000000000000001b x19: ffff0000080521e7 x18: 000000000000000d x17: 00000000000038ff x16: 0000000000000002 x15: 0000000000000007 x14: 0000000000007fff x13: ffffff0000000000 x12: 0000000000000018 x11: 000000001fffd200 x10: 00000000ffffff76 x9 : 000000000000005f x8 : ffff000008725fa8 x7 : ffff000008a8df70 x6 : ffff000008a8df70 x5 : ffff000008a8d000 x4 : 0000000000000010 x3 : 0000000000000010 x2 : 000000000000000c x1 : 0000000000000006 x0 : 0000000000000000 ... acpi_ns_lookup+0x520/0x734 acpi_ds_load1_begin_op+0x174/0x4fc acpi_ps_build_named_op+0xf8/0x220 acpi_ps_create_op+0x208/0x33c acpi_ps_parse_loop+0x204/0x838 acpi_ps_parse_aml+0x1bc/0x42c acpi_ns_one_complete_parse+0x1e8/0x22c acpi_ns_parse_table+0x8c/0x128 acpi_ns_load_table+0xc0/0x1e8 acpi_tb_load_namespace+0xf8/0x2e8 acpi_load_tables+0x7c/0x110 acpi_init+0x90/0x2c0 do_one_initcall+0x38/0x12c kernel_init_freeable+0x148/0x1ec kernel_init+0x10/0xec ret_from_fork+0x10/0x40 Code: b9009fbc 2a00037b 36380057 3219037b (b9400260) ---[ end trace 03381e5eb0a24de4 ]--- Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b With 'efi=debug', we can see those ACPI regions loaded by firmware on that board as: efi: 0x0083ff185000-0x0083ff1b4fff [Reserved | | | | | | | | |WB|WT|WC|UC]* efi: 0x0083ff1b5000-0x0083ff1c2fff [ACPI Reclaim Memory| | | | | | | | |WB|WT|WC|UC]* efi: 0x0083ff223000-0x0083ff224fff [ACPI Memory NVS | | | | | | | | |WB|WT|WC|UC]* Link: http://lkml.kernel.org/r/1468475036-5852-3-git-send-email-dennis.chen@arm.com Acked-by: Steve Capper <steve.capper@arm.com> Signed-off-by: Dennis Chen <dennis.chen@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Kaly Xin <kaly.xin@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28mm/memblock.c: add new infrastructure to address the mem limit issueDennis Chen
In some cases, memblock is queried by kernel to determine whether a specified address is RAM or not. For example, the ACPI core needs this information to determine which attributes to use when mapping ACPI regions(acpi_os_ioremap). Use of incorrect memory types can result in faults, data corruption, or other issues. Removing memory with memblock_enforce_memory_limit() throws away this information, and so a kernel booted with 'mem=' may suffer from the issues described above. To avoid this, we need to keep those NOMAP regions instead of removing all above the limit, which preserves the information we need while preventing other use of those regions. This patch adds new infrastructure to retain all NOMAP memblock regions while removing others, to cater for this. Link: http://lkml.kernel.org/r/1468475036-5852-2-git-send-email-dennis.chen@arm.com Signed-off-by: Dennis Chen <dennis.chen@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Tang Chen <tangchen@cn.fujitsu.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matt Fleming <matt@codeblueprint.co.uk> Cc: Kaly Xin <kaly.xin@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-07-28printk: when dumping regs, show the stack, not thread_infoAndy Lutomirski
We currently show: task: <current> ti: <current_thread_info()> task.ti: <task_thread_info(current)>" "ti" and "task.ti" are redundant, and neither is actually what we want to show, which the the base of the thread stack. Change the display to show the stack pointer explicitly. Link: http://lkml.kernel.org/r/543ac5bd66ff94000a57a02e11af7239571a3055.1468523549.git.luto@kernel.org Signed-off-by: Andy Lutomirski <luto@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>