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2018-12-06radix tree: Don't return retry entries from lookupMatthew Wilcox4-0/+82
Commit 66ee620f06f9 ("idr: Permit any valid kernel pointer to be stored") changed the radix tree lookup so that it stops when reaching the bottom of the tree. However, the condition was added in the wrong place, making it possible to return retry entries to the caller. Reorder the tests to check for the retry entry before checking whether we're at the bottom of the tree. The retry entry should never be found in the tree root, so it's safe to defer the check until the end of the loop. Add a regression test to the test-suite to be sure this doesn't come back. Fixes: 66ee620f06f9 ("idr: Permit any valid kernel pointer to be stored") Reported-by: Greg Kurz <groug@kaod.org> Signed-off-by: Matthew Wilcox <willy@infradead.org>
2018-12-05mm, thp: restore node-local hugepage allocationsDavid Rientjes3-29/+17
This is a full revert of ac5b2c18911f ("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings") and a partial revert of 89c83fb539f9 ("mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask"). By not setting __GFP_THISNODE, applications can allocate remote hugepages when the local node is fragmented or low on memory when either the thp defrag setting is "always" or the vma has been madvised with MADV_HUGEPAGE. Remote access to hugepages often has much higher latency than local pages of the native page size. On Haswell, ac5b2c18911f was shown to have a 13.9% access regression after this commit for binaries that remap their text segment to be backed by transparent hugepages. The intent of ac5b2c18911f is to address an issue where a local node is low on memory or fragmented such that a hugepage cannot be allocated. In every scenario where this was described as a fix, there is abundant and unfragmented remote memory available to allocate from, even with a greater access latency. If remote memory is also low or fragmented, not setting __GFP_THISNODE was also measured on Haswell to have a 40% regression in allocation latency. Restore __GFP_THISNODE for thp allocations. Fixes: ac5b2c18911f ("mm: thp: relax __GFP_THISNODE for MADV_HUGEPAGE mappings") Fixes: 89c83fb539f9 ("mm, thp: consolidate THP gfp handling into alloc_hugepage_direct_gfpmask") Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Michal Hocko <mhocko@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David Rientjes <rientjes@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-05Revert "mfd: cros_ec: Use devm_kzalloc for private data"Enric Balletbo i Serra1-1/+7
This reverts commit 3aa2177e47878f7e7616da8a2050c44f22301b6e. That commit triggered a new WARN when unloading the module (see at the end of the commit message). When a class_dev is embedded in a structure then that class_dev is the thing that controls the lifetime of that structure, for that reason device managed allocations can't be used here. See Documentation/kobject.txt. Revert the above patch, so the struct is allocated using kzalloc and we have a release function for it that frees the allocated memory, otherwise it is broken. ------------[ cut here ]------------ Device 'cros_ec' does not have a release() function, it is broken and must be fixed. WARNING: CPU: 3 PID: 3675 at drivers/base/core.c:895 device_release+0x80/0x90 Modules linked in: btusb btrtl btintel btbcm bluetooth ... CPU: 3 PID: 3675 Comm: rmmod Not tainted 4.20.0-rc4 #76 Hardware name: Google Kevin (DT) pstate: 40000005 (nZcv daif -PAN -UAO) pc : device_release+0x80/0x90 lr : device_release+0x80/0x90 sp : ffff00000c47bc70 x29: ffff00000c47bc70 x28: ffff8000e86b0d40 x27: 0000000000000000 x26: 0000000000000000 x25: 0000000056000000 x24: 0000000000000015 x23: ffff8000f0bbf860 x22: ffff000000d320a0 x21: ffff8000ee93e100 x20: ffff8000ed931428 x19: ffff8000ed931418 x18: 0000000000000020 x17: 0000000000000000 x16: 0000000000000000 x15: 0000000000000400 x14: 0000000000000143 x13: 0000000000000000 x12: 0000000000000400 x11: 0000000000000157 x10: 0000000000000960 x9 : ffff00000c47b9b0 x8 : ffff8000e86b1700 x7 : 0000000000000000 x6 : ffff8000f7d520b8 x5 : ffff8000f7d520b8 x4 : 0000000000000000 x3 : ffff8000f7d58e68 x2 : ffff8000e86b0d40 x1 : 37d859939c964800 x0 : 0000000000000000 Call trace: device_release+0x80/0x90 kobject_put+0x74/0xe8 device_unregister+0x20/0x30 ec_device_remove+0x34/0x48 [cros_ec_dev] platform_drv_remove+0x28/0x48 device_release_driver_internal+0x1a8/0x240 driver_detach+0x40/0x80 bus_remove_driver+0x54/0xa8 driver_unregister+0x2c/0x58 platform_driver_unregister+0x10/0x18 cros_ec_dev_exit+0x1c/0x2d8 [cros_ec_dev] __arm64_sys_delete_module+0x16c/0x1f8 el0_svc_common+0x84/0xd8 el0_svc_handler+0x2c/0x80 el0_svc+0x8/0xc ---[ end trace a57c4625f3c60ae8 ]--- Cc: stable@vger.kernel.org Fixes: 3aa2177e4787 ("mfd: cros_ec: Use devm_kzalloc for private data") Signed-off-by: Enric Balletbo i Serra <enric.balletbo@collabora.com> Reviewed-by: Guenter Roeck <groeck@chromium.org> Reviewed-by: Dmitry Torokhov <dtor@chromium.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-12-04blk-mq: fix corruption with direct issueJens Axboe1-1/+25
If we attempt a direct issue to a SCSI device, and it returns BUSY, then we queue the request up normally. However, the SCSI layer may have already setup SG tables etc for this particular command. If we later merge with this request, then the old tables are no longer valid. Once we issue the IO, we only read/write the original part of the request, not the new state of it. This causes data corruption, and is most often noticed with the file system complaining about the just read data being invalid: [ 235.934465] EXT4-fs error (device sda1): ext4_iget:4831: inode #7142: comm dpkg-query: bad extra_isize 24937 (inode size 256) because most of it is garbage... This doesn't happen from the normal issue path, as we will simply defer the request to the hardware queue dispatch list if we fail. Once it's on the dispatch list, we never merge with it. Fix this from the direct issue path by flagging the request as REQ_NOMERGE so we don't change the size of it before issue. See also: https://bugzilla.kernel.org/show_bug.cgi?id=201685 Tested-by: Guenter Roeck <linux@roeck-us.net> Fixes: 6ce3dd6eec1 ("blk-mq: issue directly if hw queue isn't busy in case of 'none'") Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-04Revert "exec: make de_thread() freezable"Rafael J. Wysocki1-3/+2
Revert commit c22397888f1e "exec: make de_thread() freezable" as requested by Ingo Molnar: "So there's a new regression in v4.20-rc4, my desktop produces this lockdep splat: [ 1772.588771] WARNING: pkexec/4633 still has locks held! [ 1772.588773] 4.20.0-rc4-custom-00213-g93a49841322b #1 Not tainted [ 1772.588775] ------------------------------------ [ 1772.588776] 1 lock held by pkexec/4633: [ 1772.588778] #0: 00000000ed85fbf8 (&sig->cred_guard_mutex){+.+.}, at: prepare_bprm_creds+0x2a/0x70 [ 1772.588786] stack backtrace: [ 1772.588789] CPU: 7 PID: 4633 Comm: pkexec Not tainted 4.20.0-rc4-custom-00213-g93a49841322b #1 [ 1772.588792] Call Trace: [ 1772.588800] dump_stack+0x85/0xcb [ 1772.588803] flush_old_exec+0x116/0x890 [ 1772.588807] ? load_elf_phdrs+0x72/0xb0 [ 1772.588809] load_elf_binary+0x291/0x1620 [ 1772.588815] ? sched_clock+0x5/0x10 [ 1772.588817] ? search_binary_handler+0x6d/0x240 [ 1772.588820] search_binary_handler+0x80/0x240 [ 1772.588823] load_script+0x201/0x220 [ 1772.588825] search_binary_handler+0x80/0x240 [ 1772.588828] __do_execve_file.isra.32+0x7d2/0xa60 [ 1772.588832] ? strncpy_from_user+0x40/0x180 [ 1772.588835] __x64_sys_execve+0x34/0x40 [ 1772.588838] do_syscall_64+0x60/0x1c0 The warning gets triggered by an ancient lockdep check in the freezer: (gdb) list *0xffffffff812ece06 0xffffffff812ece06 is in flush_old_exec (./include/linux/freezer.h:57). 52 * DO NOT ADD ANY NEW CALLERS OF THIS FUNCTION 53 * If try_to_freeze causes a lockdep warning it means the caller may deadlock 54 */ 55 static inline bool try_to_freeze_unsafe(void) 56 { 57 might_sleep(); 58 if (likely(!freezing(current))) 59 return false; 60 return __refrigerator(false); 61 } I reviewed the ->cred_guard_mutex code, and the mutex is held across all of exec() - and we always did this. But there's this recent -rc4 commit: > Chanho Min (1): > exec: make de_thread() freezable c22397888f1e: exec: make de_thread() freezable I believe this commit is bogus, you cannot call try_to_freeze() from de_thread(), because it's holding the ->cred_guard_mutex." Reported-by: Ingo Molnar <mingo@kernel.org> Tested-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2018-12-04btrfs: tree-checker: Don't check max block group size as current max chunk size limit is unreliableQu Wenruo1-5/+3
[BUG] A completely valid btrfs will refuse to mount, with error message like: BTRFS critical (device sdb2): corrupt leaf: root=2 block=239681536 slot=172 \ bg_start=12018974720 bg_len=10888413184, invalid block group size, \ have 10888413184 expect (0, 10737418240] This has been reported several times as the 4.19 kernel is now being used. The filesystem refuses to mount, but is otherwise ok and booting 4.18 is a workaround. Btrfs check returns no error, and all kernels used on this fs is later than 2011, which should all have the 10G size limit commit. [CAUSE] For a 12 devices btrfs, we could allocate a chunk larger than 10G due to stripe stripe bump up. __btrfs_alloc_chunk() |- max_stripe_size = 1G |- max_chunk_size = 10G |- data_stripe = 11 |- if (1G * 11 > 10G) { stripe_size = 976128930; stripe_size = round_up(976128930, SZ_16M) = 989855744 However the final stripe_size (989855744) * 11 = 10888413184, which is still larger than 10G. [FIX] For the comprehensive check, we need to do the full check at chunk read time, and rely on bg <-> chunk mapping to do the check. We could just skip the length check for now. Fixes: fce466eab7ac ("btrfs: tree-checker: Verify block_group_item") Cc: stable@vger.kernel.org # v4.19+ Reported-by: Wang Yugui <wangyugui@e16-tech.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-03libata: whitelist all SAMSUNG MZ7KM* solid-state disksJuha-Matti Tilli1-0/+1
These devices support read zero after trim (RZAT), as they advertise to the OS. However, the OS doesn't believe the SSDs unless they are explicitly whitelisted. Acked-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Juha-Matti Tilli <juha-matti.tilli@iki.fi> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-12-03Input: omap-keypad - fix keyboard debounce configurationTony Lindgren1-4/+14
I noticed that the Android v3.0.8 kernel on droid4 is using different keypad values from the mainline kernel and does not have issues with keys occasionally being stuck until pressed again. Turns out there was an earlier patch posted to fix this as "Input: omap-keypad: errata i689: Correct debounce time", but it was never reposted to fix use macros for timing calculations. This updated version is using macros, and also fixes the use of the input clock rate to use 32768KiHz instead of 32000KiHz. And we want to use the known good Android kernel values of 3 and 6 instead of 2 and 6 in the earlier patch. Reported-by: Pavel Machek <pavel@ucw.cz> Signed-off-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-12-03Input: xpad - quirk all PDP Xbox One gamepadsCameron Gutman1-10/+6
Since we continue to find tons of new variants [0,1,2,3,4,5,6] that need the PDP quirk, let's just quirk all devices from PDP. [0]: https://github.com/paroj/xpad/pull/104 [1]: https://github.com/paroj/xpad/pull/105 [2]: https://github.com/paroj/xpad/pull/108 [3]: https://github.com/paroj/xpad/pull/109 [4]: https://github.com/paroj/xpad/pull/112 [5]: https://github.com/paroj/xpad/pull/115 [6]: https://github.com/paroj/xpad/pull/116 Fixes: e5c9c6a885fa ("Input: xpad - add support for PDP Xbox One controllers") Cc: stable@vger.kernel.org Signed-off-by: Cameron Gutman <aicommander@gmail.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-12-03Input: synaptics - enable SMBus for HP 15-ay000Teika Kazura1-0/+1
SMBus works fine for the touchpad with id SYN3221, used in the HP 15-ay000 series, This device has been reported in these messages in the "linux-input" mailing list: * https://marc.info/?l=linux-input&m=152016683003369&w=2 * https://www.spinics.net/lists/linux-input/msg52525.html Reported-by: Nitesh Debnath <niteshkd1999@gmail.com> Reported-by: Teika Kazura <teika@gmx.com> Signed-off-by: Teika Kazura <teika@gmx.com> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-12-03Input: synaptics - add PNP ID for ThinkPad P50 to SMBusLyude Paul1-0/+1
Noticed the other day the trackpoint felt different on my P50, then realized it was because rmi4 wasn't loading for this machine automatically. Suspend/resume, hibernate, and everything else seem to work perfectly fine on here. Signed-off-by: Lyude Paul <lyude@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-12-03Input: elan_i2c - add ACPI ID for Lenovo IdeaPad 330-15ARRNoah Westervelt1-0/+1
Add ELAN061E to the ACPI table to support Elan touchpad found in Lenovo IdeaPad 330-15ARR. Signed-off-by: Noah Westervelt <nwestervelt@outlook.com> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-12-03Input: elan_i2c - add support for ELAN0621 touchpadAdam Wong1-0/+1
Added the ability to detect the ELAN0621 touchpad found in some Lenovo laptops. Signed-off-by: Adam Wong <adam@adamwong.me> Cc: stable@vger.kernel.org Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
2018-12-02ide: Change to use DEFINE_SHOW_ATTRIBUTE macroYangtao Li1-13/+2
Use DEFINE_SHOW_ATTRIBUTE macro to simplify the code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-02ide: pmac: add of_node_put()Yangtao Li1-0/+1
use of_node_put() to release the refcount. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-02drivers/tty: add missing of_node_put()Yangtao Li1-0/+1
of_find_node_by_path() acquires a reference to the node returned by it and that reference needs to be dropped by its caller. This place is not doing this, so fix it. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-02drivers/sbus/char: add of_node_put()Yangtao Li1-0/+2
use of_node_put() to release the refcount. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-02sbus: char: add of_node_put()Yangtao Li1-0/+1
use of_node_put() to release the refcount. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2018-12-02Linux 4.20-rc5Linus Torvalds1-1/+1
2018-12-02parisc: Enable -ffunction-sections for modules on 32-bit kernelHelge Deller1-0/+7
Frank Schreiner reported, that since kernel 4.18 he faces sysfs-warnings when loading modules on a 32-bit kernel. Here is one such example: sysfs: cannot create duplicate filename '/module/nfs/sections/.text' CPU: 0 PID: 98 Comm: modprobe Not tainted 4.18.0-2-parisc #1 Debian 4.18.10-2 Backtrace: [<1017ce2c>] show_stack+0x3c/0x50 [<107a7210>] dump_stack+0x28/0x38 [<103f900c>] sysfs_warn_dup+0x88/0xac [<103f8b1c>] sysfs_add_file_mode_ns+0x164/0x1d0 [<103f9e70>] internal_create_group+0x11c/0x304 [<103fa0a0>] sysfs_create_group+0x48/0x60 [<1022abe8>] load_module.constprop.35+0x1f9c/0x23b8 [<1022b278>] sys_finit_module+0xd0/0x11c [<101831dc>] syscall_exit+0x0/0x14 This warning gets triggered by the fact, that due to commit 24b6c22504a2 ("parisc: Build kernel without -ffunction-sections") we now get multiple .text sections in the kernel modules for which sysfs_create_group() can't create multiple virtual files. This patch works around the problem by re-enabling the -ffunction-sections compiler option for modules, while keeping it disabled for the non-module kernel code. Reported-by: Frank Scheiner <frank.scheiner@web.de> Fixes: 24b6c22504a2 ("parisc: Build kernel without -ffunction-sections") Cc: <stable@vger.kernel.org> # v4.18+ Signed-off-by: Helge Deller <deller@gmx.de>
2018-11-30PCI: Fix incorrect value returned from pcie_get_speed_cap()Mikulas Patocka1-13/+11
The macros PCI_EXP_LNKCAP_SLS_*GB are values, not bit masks. We must mask the register and compare it against them. This fixes errors like this: amdgpu: [powerplay] failed to send message 261 ret is 0 when a PCIe-v3 card is plugged into a PCIe-v1 slot, because the slot is being incorrectly reported as PCIe-v3 capable. 6cf57be0f78e, which appeared in v4.17, added pcie_get_speed_cap() with the incorrect test of PCI_EXP_LNKCAP_SLS as a bitmask. 5d9a63304032, which appeared in v4.19, changed amdgpu to use pcie_get_speed_cap(), so the amdgpu bug reports below are regressions in v4.19. Fixes: 6cf57be0f78e ("PCI: Add pcie_get_speed_cap() to find max supported link speed") Fixes: 5d9a63304032 ("drm/amdgpu: use pcie functions for link width and speed") Link: https://bugs.freedesktop.org/show_bug.cgi?id=108704 Link: https://bugs.freedesktop.org/show_bug.cgi?id=108778 Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> [bhelgaas: update comment, remove use of PCI_EXP_LNKCAP_SLS_8_0GB and PCI_EXP_LNKCAP_SLS_16_0GB since those should be covered by PCI_EXP_LNKCAP2, remove test of PCI_EXP_LNKCAP for zero, since that register is required] Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Alex Deucher <alexander.deucher@amd.com> Cc: stable@vger.kernel.org # v4.17+
2018-11-30MAINTAINERS: Update linux-mips mailing list addressPaul Burton1-23/+23
The linux-mips.org infrastructure has been unreliable recently & nobody with sufficient access to fix it is around to do so. As a result we're moving away from it, and part of this is migrating our mailing list to kernel.org. Replace all instances of linux-mips@linux-mips.org in MAINTAINERS with the shiny new linux-mips@vger.kernel.org address. The new list is now being archived on kernel.org at https://lore.kernel.org/linux-mips/ which also holds the history of the old linux-mips.org list. Signed-off-by: Paul Burton <paul.burton@mips.com> Cc: linux-mips@vger.kernel.org Cc: linux-mips@linux-mips.org
2018-11-30ocfs2: fix potential use after freePan Bian1-1/+1
ocfs2_get_dentry() calls iput(inode) to drop the reference count of inode, and if the reference count hits 0, inode is freed. However, in this function, it then reads inode->i_generation, which may result in a use after free bug. Move the put operation later. Link: http://lkml.kernel.org/r/1543109237-110227-1-git-send-email-bianpan2016@163.com Fixes: 781f200cb7a("ocfs2: Remove masklog ML_EXPORT.") Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Cc: Changwei Ge <ge.changwei@h3c.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: fix the xas_create_range() error pathHugh Dickins1-11/+14
collapse_shmem()'s xas_nomem() is very unlikely to fail, but it is rightly given a failure path, so move the whole xas_create_range() block up before __SetPageLocked(new_page): so that it does not need to remember to unlock_page(new_page). Add the missing mem_cgroup_cancel_charge(), and set (currently unused) result to SCAN_FAIL rather than SCAN_SUCCEED. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261531200.2275@eggly.anvils Fixes: 77da9389b9d5 ("mm: Convert collapse_shmem to XArray") Signed-off-by: Hugh Dickins <hughd@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: collapse_shmem() do not crash on CompoundHugh Dickins1-1/+9
collapse_shmem()'s VM_BUG_ON_PAGE(PageTransCompound) was unsafe: before it holds page lock of the first page, racing truncation then extension might conceivably have inserted a hugepage there already. Fail with the SCAN_PAGE_COMPOUND result, instead of crashing (CONFIG_DEBUG_VM=y) or otherwise mishandling the unexpected hugepage - though later we might code up a more constructive way of handling it, with SCAN_SUCCESS. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261529310.2275@eggly.anvils Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: collapse_shmem() without freezing new_pageHugh Dickins1-12/+7
khugepaged's collapse_shmem() does almost all of its work, to assemble the huge new_page from 512 scattered old pages, with the new_page's refcount frozen to 0 (and refcounts of all old pages so far also frozen to 0). Including shmem_getpage() to read in any which were out on swap, memory reclaim if necessary to allocate their intermediate pages, and copying over all the data from old to new. Imagine the frozen refcount as a spinlock held, but without any lock debugging to highlight the abuse: it's not good, and under serious load heads into lockups - speculative getters of the page are not expecting to spin while khugepaged is rescheduled. One can get a little further under load by hacking around elsewhere; but fortunately, freezing the new_page turns out to have been entirely unnecessary, with no hacks needed elsewhere. The huge new_page lock is already held throughout, and guards all its subpages as they are brought one by one into the page cache tree; and anything reading the data in that page, without the lock, before it has been marked PageUptodate, would already be in the wrong. So simply eliminate the freezing of the new_page. Each of the old pages remains frozen with refcount 0 after it has been replaced by a new_page subpage in the page cache tree, until they are all unfrozen on success or failure: just as before. They could be unfrozen sooner, but cause no problem once no longer visible to find_get_entry(), filemap_map_pages() and other speculative lookups. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261527570.2275@eggly.anvils Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: minor reorderings in collapse_shmem()Hugh Dickins1-40/+32
Several cleanups in collapse_shmem(): most of which probably do not really matter, beyond doing things in a more familiar and reassuring order. Simplify the failure gotos in the main loop, and on success update stats while interrupts still disabled from the last iteration. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261526400.2275@eggly.anvils Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: collapse_shmem() remember to clear holesHugh Dickins1-0/+10
Huge tmpfs testing reminds us that there is no __GFP_ZERO in the gfp flags khugepaged uses to allocate a huge page - in all common cases it would just be a waste of effort - so collapse_shmem() must remember to clear out any holes that it instantiates. The obvious place to do so, where they are put into the page cache tree, is not a good choice: because interrupts are disabled there. Leave it until further down, once success is assured, where the other pages are copied (before setting PageUptodate). Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261525080.2275@eggly.anvils Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: fix crashes due to misaccounted holesHugh Dickins2-2/+9
Huge tmpfs testing on a shortish file mapped into a pmd-rounded extent hit shmem_evict_inode()'s WARN_ON(inode->i_blocks) followed by clear_inode()'s BUG_ON(inode->i_data.nrpages) when the file was later closed and unlinked. khugepaged's collapse_shmem() was forgetting to update mapping->nrpages on the rollback path, after it had added but then needs to undo some holes. There is indeed an irritating asymmetry between shmem_charge(), whose callers want it to increment nrpages after successfully accounting blocks, and shmem_uncharge(), when __delete_from_page_cache() already decremented nrpages itself: oh well, just add a comment on that to them both. And shmem_recalc_inode() is supposed to be called when the accounting is expected to be in balance (so it can deduce from imbalance that reclaim discarded some pages): so change shmem_charge() to update nrpages earlier (though it's rare for the difference to matter at all). Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261523450.2275@eggly.anvils Fixes: 800d8c63b2e98 ("shmem: add huge pages support") Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/khugepaged: collapse_shmem() stop if punched or truncatedHugh Dickins1-0/+11
Huge tmpfs testing showed that although collapse_shmem() recognizes a concurrently truncated or hole-punched page correctly, its handling of holes was liable to refill an emptied extent. Add check to stop that. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261522040.2275@eggly.anvils Fixes: f3f0e1d2150b2 ("khugepaged: add support of collapse for tmpfs/shmem pages") Signed-off-by: Hugh Dickins <hughd@google.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()Hugh Dickins1-6/+13
Huge tmpfs testing, on 32-bit kernel with lockdep enabled, showed that __split_huge_page() was using i_size_read() while holding the irq-safe lru_lock and page tree lock, but the 32-bit i_size_read() uses an irq-unsafe seqlock which should not be nested inside them. Instead, read the i_size earlier in split_huge_page_to_list(), and pass the end offset down to __split_huge_page(): all while holding head page lock, which is enough to prevent truncation of that extent before the page tree lock has been taken. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261520070.2275@eggly.anvils Fixes: baa355fd33142 ("thp: file pages support for split_huge_page()") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/huge_memory: splitting set mapping+index before unfreezeHugh Dickins1-6/+6
Huge tmpfs stress testing has occasionally hit shmem_undo_range()'s VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page). Move the setting of mapping and index up before the page_ref_unfreeze() in __split_huge_page_tail() to fix this: so that a page cache lookup cannot get a reference while the tail's mapping and index are unstable. In fact, might as well move them up before the smp_wmb(): I don't see an actual need for that, but if I'm missing something, this way round is safer than the other, and no less efficient. You might argue that VM_BUG_ON_PAGE(page_to_pgoff(page) != index, page) is misplaced, and should be left until after the trylock_page(); but left as is has not crashed since, and gives more stringent assurance. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261516380.2275@eggly.anvils Fixes: e9b61f19858a5 ("thp: reintroduce split_huge_page()") Requires: 605ca5ede764 ("mm/huge_memory.c: reorder operations in __split_huge_page_tail()") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/huge_memory: rename freeze_page() to unmap_page()Hugh Dickins2-16/+9
The term "freeze" is used in several ways in the kernel, and in mm it has the particular meaning of forcing page refcount temporarily to 0. freeze_page() is just too confusing a name for a function that unmaps a page: rename it unmap_page(), and rename unfreeze_page() remap_page(). Went to change the mention of freeze_page() added later in mm/rmap.c, but found it to be incorrect: ordinary page reclaim reaches there too; but the substance of the comment still seems correct, so edit it down. Link: http://lkml.kernel.org/r/alpine.LSU.2.11.1811261514080.2275@eggly.anvils Fixes: e9b61f19858a5 ("thp: reintroduce split_huge_page()") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Jerome Glisse <jglisse@redhat.com> Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> [4.8+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30initramfs: clean old path before creating a hardlinkLi Zhijian1-10/+12
sys_link() can fail due to the new path already existing. This case ofen occurs when we use a concated initrd, for example: 1) prepare a basic rootfs, it contains a regular files rc.local lizhijian@:~/yocto-tiny-i386-2016-04-22$ cat etc/rc.local #!/bin/sh echo "Running /etc/rc.local..." yocto-tiny-i386-2016-04-22$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n -9 >../rootfs.cgz 2) create a extra initrd which also includes a etc/rc.local lizhijian@:~/lkp-x86_64/etc$ echo "append initrd" >rc.local lizhijian@:~/lkp/lkp-x86_64/etc$ cat rc.local append initrd lizhijian@:~/lkp/lkp-x86_64/etc$ ln rc.local rc.local.hardlink append initrd lizhijian@:~/lkp/lkp-x86_64/etc$ stat rc.local rc.local.hardlink File: 'rc.local' Size: 14 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 11296086 Links: 2 Access: (0664/-rw-rw-r--) Uid: ( 1002/lizhijian) Gid: ( 1002/lizhijian) Access: 2018-11-15 16:08:28.654464815 +0800 Modify: 2018-11-15 16:07:57.514903210 +0800 Change: 2018-11-15 16:08:24.180228872 +0800 Birth: - File: 'rc.local.hardlink' Size: 14 Blocks: 8 IO Block: 4096 regular file Device: 801h/2049d Inode: 11296086 Links: 2 Access: (0664/-rw-rw-r--) Uid: ( 1002/lizhijian) Gid: ( 1002/lizhijian) Access: 2018-11-15 16:08:28.654464815 +0800 Modify: 2018-11-15 16:07:57.514903210 +0800 Change: 2018-11-15 16:08:24.180228872 +0800 Birth: - lizhijian@:~/lkp/lkp-x86_64$ find . | sed 's,^\./,,' | cpio -o -H newc | gzip -n -9 >../rc-local.cgz lizhijian@:~/lkp/lkp-x86_64$ gzip -dc ../rc-local.cgz | cpio -t . etc etc/rc.local.hardlink <<< it will be extracted first at this initrd etc/rc.local 3) concate 2 initrds and boot lizhijian@:~/lkp$ cat rootfs.cgz rc-local.cgz >concate-initrd.cgz lizhijian@:~/lkp$ qemu-system-x86_64 -nographic -enable-kvm -cpu host -smp 1 -m 1024 -kernel ~/lkp/linux/arch/x86/boot/bzImage -append "console=ttyS0 earlyprint=ttyS0 ignore_loglevel" -initrd ./concate-initr.cgz -serial stdio -nodefaults In this case, sys_link(2) will fail and return -EEXIST, so we can only get the rc.local at rootfs.cgz instead of rc-local.cgz [akpm@linux-foundation.org: move code to avoid forward declaration] Link: http://lkml.kernel.org/r/1542352368-13299-1-git-send-email-lizhijian@cn.fujitsu.com Signed-off-by: Li Zhijian <lizhijian@cn.fujitsu.com> Cc: Philip Li <philip.li@intel.com> Cc: Dominik Brodowski <linux@dominikbrodowski.net> Cc: Li Zhijian <zhijianx.li@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30kernel/kcov.c: mark funcs in __sanitizer_cov_trace_pc() as notraceAnders Roxell1-2/+2
Since __sanitizer_cov_trace_pc() is marked as notrace, function calls in __sanitizer_cov_trace_pc() shouldn't be traced either. ftrace_graph_caller() gets called for each function that isn't marked 'notrace', like canonicalize_ip(). This is the call trace from a run: [ 139.644550] ftrace_graph_caller+0x1c/0x24 [ 139.648352] canonicalize_ip+0x18/0x28 [ 139.652313] __sanitizer_cov_trace_pc+0x14/0x58 [ 139.656184] sched_clock+0x34/0x1e8 [ 139.659759] trace_clock_local+0x40/0x88 [ 139.663722] ftrace_push_return_trace+0x8c/0x1f0 [ 139.667767] prepare_ftrace_return+0xa8/0x100 [ 139.671709] ftrace_graph_caller+0x1c/0x24 Rework so that check_kcov_mode() and canonicalize_ip() that are called from __sanitizer_cov_trace_pc() are also marked as notrace. Link: http://lkml.kernel.org/r/20181128081239.18317-1-anders.roxell@linaro.org Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signen-off-by: Anders Roxell <anders.roxell@linaro.org> Co-developed-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30psi: make disabling/enabling easier for vendor kernelsJohannes Weiner5-14/+40
Mel Gorman reports a hackbench regression with psi that would prohibit shipping the suse kernel with it default-enabled, but he'd still like users to be able to opt in at little to no cost to others. With the current combination of CONFIG_PSI and the psi_disabled bool set from the commandline, this is a challenge. Do the following things to make it easier: 1. Add a config option CONFIG_PSI_DEFAULT_DISABLED that allows distros to enable CONFIG_PSI in their kernel but leave the feature disabled unless a user requests it at boot-time. To avoid double negatives, rename psi_disabled= to psi=. 2. Make psi_disabled a static branch to eliminate any branch costs when the feature is disabled. In terms of numbers before and after this patch, Mel says: : The following is a comparision using CONFIG_PSI=n as a baseline against : your patch and a vanilla kernel : : 4.20.0-rc4 4.20.0-rc4 4.20.0-rc4 : kconfigdisable-v1r1 vanilla psidisable-v1r1 : Amean 1 1.3100 ( 0.00%) 1.3923 ( -6.28%) 1.3427 ( -2.49%) : Amean 3 3.8860 ( 0.00%) 4.1230 * -6.10%* 3.8860 ( -0.00%) : Amean 5 6.8847 ( 0.00%) 8.0390 * -16.77%* 6.7727 ( 1.63%) : Amean 7 9.9310 ( 0.00%) 10.8367 * -9.12%* 9.9910 ( -0.60%) : Amean 12 16.6577 ( 0.00%) 18.2363 * -9.48%* 17.1083 ( -2.71%) : Amean 18 26.5133 ( 0.00%) 27.8833 * -5.17%* 25.7663 ( 2.82%) : Amean 24 34.3003 ( 0.00%) 34.6830 ( -1.12%) 32.0450 ( 6.58%) : Amean 30 40.0063 ( 0.00%) 40.5800 ( -1.43%) 41.5087 ( -3.76%) : Amean 32 40.1407 ( 0.00%) 41.2273 ( -2.71%) 39.9417 ( 0.50%) : : It's showing that the vanilla kernel takes a hit (as the bisection : indicated it would) and that disabling PSI by default is reasonably : close in terms of performance for this particular workload on this : particular machine so; Link: http://lkml.kernel.org/r/20181127165329.GA29728@cmpxchg.org Signed-off-by: Johannes Weiner <hannes@cmpxchg.org> Tested-by: Mel Gorman <mgorman@techsingularity.net> Reported-by: Mel Gorman <mgorman@techsingularity.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30proc: fixup map_files test on armAlexey Dobriyan1-2/+7
https://bugs.linaro.org/show_bug.cgi?id=3782 Turns out arm doesn't permit mapping address 0, so try minimum virtual address instead. Link: http://lkml.kernel.org/r/20181113165446.GA28157@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reported-by: Rafael David Tinoco <rafael.tinoco@linaro.org> Tested-by: Rafael David Tinoco <rafael.tinoco@linaro.org> Acked-by: Cyrill Gorcunov <gorcunov@gmail.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30debugobjects: avoid recursive calls with kmemleakQian Cai1-3/+2
CONFIG_DEBUG_OBJECTS_RCU_HEAD does not play well with kmemleak due to recursive calls. fill_pool kmemleak_ignore make_black_object put_object __call_rcu (kernel/rcu/tree.c) debug_rcu_head_queue debug_object_activate debug_object_init fill_pool kmemleak_ignore make_black_object ... So add SLAB_NOLEAKTRACE to kmem_cache_create() to not register newly allocated debug objects at all. Link: http://lkml.kernel.org/r/20181126165343.2339-1-cai@gmx.us Signed-off-by: Qian Cai <cai@gmx.us> Suggested-by: Catalin Marinas <catalin.marinas@arm.com> Acked-by: Waiman Long <longman@redhat.com> Acked-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Yang Shi <yang.shi@linux.alibaba.com> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30userfaultfd: shmem: UFFDIO_COPY: set the page dirty if VM_WRITE is not setAndrea Arcangeli1-0/+11
Set the page dirty if VM_WRITE is not set because in such case the pte won't be marked dirty and the page would be reclaimed without writepage (i.e. swapout in the shmem case). This was found by source review. Most apps (certainly including QEMU) only use UFFDIO_COPY on PROT_READ|PROT_WRITE mappings or the app can't modify the memory in the first place. This is for correctness and it could help the non cooperative use case to avoid unexpected data loss. Link: http://lkml.kernel.org/r/20181126173452.26955-6-aarcange@redhat.com Reviewed-by: Hugh Dickins <hughd@google.com> Cc: stable@vger.kernel.org Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support") Reported-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Mike Rapoport <rppt@linux.ibm.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30userfaultfd: shmem: add i_size checksAndrea Arcangeli2-4/+40
With MAP_SHARED: recheck the i_size after taking the PT lock, to serialize against truncate with the PT lock. Delete the page from the pagecache if the i_size_read check fails. With MAP_PRIVATE: check the i_size after the PT lock before mapping anonymous memory or zeropages into the MAP_PRIVATE shmem mapping. A mostly irrelevant cleanup: like we do the delete_from_page_cache() pagecache removal after dropping the PT lock, the PT lock is a spinlock so drop it before the sleepable page lock. Link: http://lkml.kernel.org/r/20181126173452.26955-5-aarcange@redhat.com Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Hugh Dickins <hughd@google.com> Reported-by: Jann Horn <jannh@google.com> Cc: <stable@vger.kernel.org> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30userfaultfd: shmem/hugetlbfs: only allow to register VM_MAYWRITE vmasAndrea Arcangeli2-9/+21
After the VMA to register the uffd onto is found, check that it has VM_MAYWRITE set before allowing registration. This way we inherit all common code checks before allowing to fill file holes in shmem and hugetlbfs with UFFDIO_COPY. The userfaultfd memory model is not applicable for readonly files unless it's a MAP_PRIVATE. Link: http://lkml.kernel.org/r/20181126173452.26955-4-aarcange@redhat.com Fixes: ff62a3421044 ("hugetlb: implement memfd sealing") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Hugh Dickins <hughd@google.com> Reported-by: Jann Horn <jannh@google.com> Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support") Cc: <stable@vger.kernel.org> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30userfaultfd: shmem: allocate anonymous memory for MAP_PRIVATE shmemAndrea Arcangeli1-2/+13
Userfaultfd did not create private memory when UFFDIO_COPY was invoked on a MAP_PRIVATE shmem mapping. Instead it wrote to the shmem file, even when that had not been opened for writing. Though, fortunately, that could only happen where there was a hole in the file. Fix the shmem-backed implementation of UFFDIO_COPY to create private memory for MAP_PRIVATE mappings. The hugetlbfs-backed implementation was already correct. This change is visible to userland, if userfaultfd has been used in unintended ways: so it introduces a small risk of incompatibility, but is necessary in order to respect file permissions. An app that uses UFFDIO_COPY for anything like postcopy live migration won't notice the difference, and in fact it'll run faster because there will be no copy-on-write and memory waste in the tmpfs pagecache anymore. Userfaults on MAP_PRIVATE shmem keep triggering only on file holes like before. The real zeropage can also be built on a MAP_PRIVATE shmem mapping through UFFDIO_ZEROPAGE and that's safe because the zeropage pte is never dirty, in turn even an mprotect upgrading the vma permission from PROT_READ to PROT_READ|PROT_WRITE won't make the zeropage pte writable. Link: http://lkml.kernel.org/r/20181126173452.26955-3-aarcange@redhat.com Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reported-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Peter Xu <peterx@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30userfaultfd: use ENOENT instead of EFAULT if the atomic copy user failsAndrea Arcangeli3-5/+5
Patch series "userfaultfd shmem updates". Jann found two bugs in the userfaultfd shmem MAP_SHARED backend: the lack of the VM_MAYWRITE check and the lack of i_size checks. Then looking into the above we also fixed the MAP_PRIVATE case. Hugh by source review also found a data loss source if UFFDIO_COPY is used on shmem MAP_SHARED PROT_READ mappings (the production usages incidentally run with PROT_READ|PROT_WRITE, so the data loss couldn't happen in those production usages like with QEMU). The whole patchset is marked for stable. We verified QEMU postcopy live migration with guest running on shmem MAP_PRIVATE run as well as before after the fix of shmem MAP_PRIVATE. Regardless if it's shmem or hugetlbfs or MAP_PRIVATE or MAP_SHARED, QEMU unconditionally invokes a punch hole if the guest mapping is filebacked and a MADV_DONTNEED too (needed to get rid of the MAP_PRIVATE COWs and for the anon backend). This patch (of 5): We internally used EFAULT to communicate with the caller, switch to ENOENT, so EFAULT can be used as a non internal retval. Link: http://lkml.kernel.org/r/20181126173452.26955-2-aarcange@redhat.com Fixes: 4c27fe4c4c84 ("userfaultfd: shmem: add shmem_mcopy_atomic_pte for userfaultfd support") Signed-off-by: Andrea Arcangeli <aarcange@redhat.com> Reviewed-by: Mike Rapoport <rppt@linux.ibm.com> Reviewed-by: Hugh Dickins <hughd@google.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Jann Horn <jannh@google.com> Cc: Peter Xu <peterx@redhat.com> Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com> Cc: <stable@vger.kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30lib/test_kmod.c: fix rmmod double freeLuis Chamberlain1-1/+0
We free the misc device string twice on rmmod; fix this. Without this we cannot remove the module without crashing. Link: http://lkml.kernel.org/r/20181124050500.5257-1-mcgrof@kernel.org Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Reported-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: <stable@vger.kernel.org> [4.12+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30hfsplus: do not free node before usingPan Bian1-1/+2
hfs_bmap_free() frees node via hfs_bnode_put(node). However it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees node only when it is never used. Link: http://lkml.kernel.org/r/1543053441-66942-1-git-send-email-bianpan2016@163.com Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Viacheslav Dubeyko <slava@dubeyko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30hfs: do not free node before usingPan Bian1-1/+2
hfs_bmap_free() frees the node via hfs_bnode_put(node). However, it then reads node->this when dumping error message on an error path, which may result in a use-after-free bug. This patch frees the node only when it is never again used. Link: http://lkml.kernel.org/r/1542963889-128825-1-git-send-email-bianpan2016@163.com Fixes: a1185ffa2fc ("HFS rewrite") Signed-off-by: Pan Bian <bianpan2016@163.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Cc: Joe Perches <joe@perches.com> Cc: Ernesto A. Fernandez <ernesto.mnd.fernandez@gmail.com> Cc: Viacheslav Dubeyko <slava@dubeyko.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30proc: update MAINTAINERS with proc.txtAlexey Dobriyan1-0/+1
Turns out that /proc has official documentation and people even trying to keep it uptodate. Link: http://lkml.kernel.org/r/20181116134630.GA8004@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm/page_alloc.c: fix calculation of pgdat->nr_zonesWei Yang1-1/+3
init_currently_empty_zone() will adjust pgdat->nr_zones and set it to 'zone_idx(zone) + 1' unconditionally. This is correct in the normal case, while not exact in hot-plug situation. This function is used in two places: * free_area_init_core() * move_pfn_range_to_zone() In the first case, we are sure zone index increase monotonically. While in the second one, this is under users control. One way to reproduce this is: ---------------------------- 1. create a virtual machine with empty node1 -m 4G,slots=32,maxmem=32G \ -smp 4,maxcpus=8 \ -numa node,nodeid=0,mem=4G,cpus=0-3 \ -numa node,nodeid=1,mem=0G,cpus=4-7 2. hot-add cpu 3-7 cpu-add [3-7] 2. hot-add memory to nod1 object_add memory-backend-ram,id=ram0,size=1G device_add pc-dimm,id=dimm0,memdev=ram0,node=1 3. online memory with following order echo online_movable > memory47/state echo online > memory40/state After this, node1 will have its nr_zones equals to (ZONE_NORMAL + 1) instead of (ZONE_MOVABLE + 1). Michal said: "Having an incorrect nr_zones might result in all sorts of problems which would be quite hard to debug (e.g. reclaim not considering the movable zone). I do not expect many users would suffer from this it but still this is trivial and obviously right thing to do so backporting to the stable tree shouldn't be harmful (last famous words)" Link: http://lkml.kernel.org/r/20181117022022.9956-1-richard.weiyang@gmail.com Fixes: f1dd2cd13c4b ("mm, memory_hotplug: do not associate hotadded memory to zones until online") Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm: use swp_offset as key in shmem_replace_page()Yu Zhao1-2/+4
We changed the key of swap cache tree from swp_entry_t.val to swp_offset. We need to do so in shmem_replace_page() as well. Hugh said: "shmem_replace_page() has been wrong since the day I wrote it: good enough to work on swap "type" 0, which is all most people ever use (especially those few who need shmem_replace_page() at all), but broken once there are any non-0 swp_type bits set in the higher order bits" Link: http://lkml.kernel.org/r/20181121215442.138545-1-yuzhao@google.com Fixes: f6ab1f7f6b2d ("mm, swap: use offset of swap entry as key of swap cache") Signed-off-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Matthew Wilcox <willy@infradead.org> Acked-by: Hugh Dickins <hughd@google.com> Cc: <stable@vger.kernel.org> [4.9+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-11-30mm: cleancache: fix corruption on missed inode invalidationPavel Tikhomirov1-2/+6
If all pages are deleted from the mapping by memory reclaim and also moved to the cleancache: __delete_from_page_cache (no shadow case) unaccount_page_cache_page cleancache_put_page page_cache_delete mapping->nrpages -= nr (nrpages becomes 0) We don't clean the cleancache for an inode after final file truncation (removal). truncate_inode_pages_final check (nrpages || nrexceptional) is false no truncate_inode_pages no cleancache_invalidate_inode(mapping) These way when reading the new file created with same inode we may get these trash leftover pages from cleancache and see wrong data instead of the contents of the new file. Fix it by always doing truncate_inode_pages which is already ready for nrpages == 0 && nrexceptional == 0 case and just invalidates inode. [akpm@linux-foundation.org: add comment, per Jan] Link: http://lkml.kernel.org/r/20181112095734.17979-1-ptikhomirov@virtuozzo.com Fixes: commit 91b0abe36a7b ("mm + fs: store shadow entries in page cache") Signed-off-by: Pavel Tikhomirov <ptikhomirov@virtuozzo.com> Reviewed-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@techsingularity.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Andi Kleen <ak@linux.intel.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>