- 22 Jan, 2019 9 commits
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Christian Brauner authored
In a previous commit we switched from a d_alloc_name() + d_lookup() combination to setup a new dentry and find potential duplicates to the more idiomatic lookup_one_len(). As far as I understand, this also means we need to switch from d_add() to d_instantiate() since lookup_one_len() will create a new dentry when it doesn't find an existing one and add the new dentry to the hash queues. So we only need to call d_instantiate() to connect the dentry to the inode and turn it into a positive dentry. If we were to use d_add() we sure see stack traces like the following indicating that adding the same dentry twice over the same inode: [ 744.441889] CPU: 4 PID: 2849 Comm: landscape-sysin Not tainted 5.0.0-rc1-brauner-binderfs #243 [ 744.441889] Hardware name: Dell DCS XS24-SC2 /XS24-SC2 , BIOS S59_3C20 04/07/2011 [ 744.441889] RIP: 0010:__d_lookup_rcu+0x76/0x190 [ 744.441889] Code: 89 75 c0 49 c1 e9 20 49 89 fd 45 89 ce 41 83 e6 07 42 8d 04 f5 00 00 00 00 89 45 c8 eb 0c 48 8b 1b 48 85 db 0f 84 81 00 00 00 <44> 8b 63 fc 4c 3b 6b 10 75 ea 48 83 7b 08 00 74 e3 41 83 e4 fe 41 [ 744.441889] RSP: 0018:ffffb8c984e27ad0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13 [ 744.441889] RAX: 0000000000000038 RBX: ffff9407ef770c08 RCX: ffffb8c980011000 [ 744.441889] RDX: ffffb8c984e27b54 RSI: ffffb8c984e27ce0 RDI: ffff9407e6689600 [ 744.441889] RBP: ffffb8c984e27b28 R08: ffffb8c984e27ba4 R09: 0000000000000007 [ 744.441889] R10: ffff9407e5c4f05c R11: 973f3eb9d84a94e5 R12: 0000000000000002 [ 744.441889] R13: ffff9407e6689600 R14: 0000000000000007 R15: 00000007bfef7a13 [ 744.441889] FS: 00007f0db13bb740(0000) GS:ffff9407f3b00000(0000) knlGS:0000000000000000 [ 744.441889] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 744.441889] CR2: 00007f0dacc51024 CR3: 000000032961a000 CR4: 00000000000006e0 [ 744.441889] Call Trace: [ 744.441889] lookup_fast+0x53/0x300 [ 744.441889] walk_component+0x49/0x350 [ 744.441889] ? inode_permission+0x63/0x1a0 [ 744.441889] link_path_walk.part.33+0x1bc/0x5a0 [ 744.441889] ? path_init+0x190/0x310 [ 744.441889] path_lookupat+0x95/0x210 [ 744.441889] filename_lookup+0xb6/0x190 [ 744.441889] ? __check_object_size+0xb8/0x1b0 [ 744.441889] ? strncpy_from_user+0x50/0x1a0 [ 744.441889] user_path_at_empty+0x36/0x40 [ 744.441889] ? user_path_at_empty+0x36/0x40 [ 744.441889] vfs_statx+0x76/0xe0 [ 744.441889] __do_sys_newstat+0x3d/0x70 [ 744.441889] __x64_sys_newstat+0x16/0x20 [ 744.441889] do_syscall_64+0x5a/0x120 [ 744.441889] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 744.441889] RIP: 0033:0x7f0db0ec2775 [ 744.441889] Code: 00 00 00 75 05 48 83 c4 18 c3 e8 26 55 02 00 66 0f 1f 44 00 00 83 ff 01 48 89 f0 77 30 48 89 c7 48 89 d6 b8 04 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 03 f3 c3 90 48 8b 15 e1 b6 2d 00 f7 d8 64 89 [ 744.441889] RSP: 002b:00007ffc36bc9388 EFLAGS: 00000246 ORIG_RAX: 0000000000000004 [ 744.441889] RAX: ffffffffffffffda RBX: 00007ffc36bc9300 RCX: 00007f0db0ec2775 [ 744.441889] RDX: 00007ffc36bc9400 RSI: 00007ffc36bc9400 RDI: 00007f0dad26f050 [ 744.441889] RBP: 0000000000c0bc60 R08: 0000000000000000 R09: 0000000000000001 [ 744.441889] R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffc36bc9400 [ 744.441889] R13: 0000000000000001 R14: 00000000ffffff9c R15: 0000000000c0bc60 Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Christian Brauner <christian@brauner.io> Signed-off-by:
Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Christian Brauner authored
The binderfs_binder_ctl_create() call is a no-op on subsequent calls and the first call is done before we unlock the suberblock. Hence, there is no need to take inode_lock() in there. Let's remove it. Suggested-by:
Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Christian Brauner authored
Al pointed out that first calling kill_litter_super() before cleaning up info is more correct since destroying info doesn't depend on the state of the dentries and inodes. That the opposite remains true is not guaranteed. Suggested-by:
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Christian Brauner authored
- switch from d_alloc_name() + d_lookup() to lookup_one_len(): Instead of using d_alloc_name() and then doing a d_lookup() with the allocated dentry to find whether a device with the name we're trying to create already exists switch to using lookup_one_len(). The latter will either return the existing dentry or a new one. - switch from kmalloc() + strscpy() to kmemdup(): Use a more idiomatic way to copy the name for the new dentry that userspace gave us. Suggested-by:
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Christian Brauner authored
Al pointed out that on binderfs_fill_super() error deactivate_locked_super() will call binderfs_kill_super() so all of the freeing and putting we currently do in binderfs_fill_super() is unnecessary and buggy. Let's simply return errors and let binderfs_fill_super() take care of cleaning up on error. Suggested-by:
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Christian Brauner authored
- make binderfs control dentry immutable: We don't allow to unlink it since it is crucial for binderfs to be useable but if we allow to rename it we make the unlink trivial to bypass. So prevent renaming too and simply treat the control dentry as immutable. - add is_binderfs_control_device() helper: Take the opportunity and turn the check for the control dentry into a separate helper is_binderfs_control_device() since it's now used in two places. - simplify binderfs_rename(): Instead of hand-rolling our custom version of simple_rename() just dumb the whole function down to first check whether we're trying to rename the control dentry. If we do EPERM the caller and if not call simple_rename(). Suggested-by:
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Christian Brauner authored
The comment stems from an early version of that patchset and is just confusing now. Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
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Christian Brauner authored
We allow more then 255 binderfs binder devices to be created since there are workloads that require more than that. If we use __u8 we'll overflow after 255. So let's use a __u32. Note that there's no released kernel with binderfs out there so this is not a regression. Signed-off-by:
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Christian Brauner authored
When we switched over from binder_ctl.h to binderfs.h we forgot to change the include guards. It's minor but it's obviously correct. Signed-off-by:
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- 18 Jan, 2019 4 commits
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Anders Roxell authored
When building and have fragment CONFIG_NO_IOPORT_MAP enabled then the following warning: ../drivers/misc/pvpanic.c: In function ‘pvpanic_walk_resources’: ../drivers/misc/pvpanic.c:73:10: error: implicit declaration of function ‘ioport_map’; did you mean ‘ioremap’? [-Werror=implicit-function-declaration] base = ioport_map(r.start, resource_size(&r)); ^~~~~~~~~~ Since commmit 5d32a665 ("PCI/ACPI: Allow ACPI to be built without CONFIG_PCI set"), its now possible to have ACPI enabled without haveing PCI enabled. However, the pvpanic driver depends on HAS_IOPORT_MAP or HAVE_IOREMAP_PROT when ACPI is enabled. It was fine until commit 725eba29 ("misc/pvpanic: add MMIO support") got added. Rework so that we do a extra check ifdef CONFIG_HAS_IOPORT_MAP. Fixes: 5d32a665 ("PCI/ACPI: Allow ACPI to be built without CONFIG_PCI set") Suggested-by:Arnd Bergmann <arnd@arndb.de> Signed-off-by:
Anders Roxell <anders.roxell@linaro.org> Signed-off-by:
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Gustavo A. R. Silva authored
ipcnum is indirectly controlled by user-space, hence leading to a potential exploitation of the Spectre variant 1 vulnerability. This issue was detected with the help of Smatch: drivers/char/mwave/mwavedd.c:299 mwave_ioctl() warn: potential spectre issue 'pDrvData->IPCs' [w] (local cap) Fix this by sanitizing ipcnum before using it to index pDrvData->IPCs. Notice that given that speculation windows are large, the policy is to kill the speculation on the first load and not worry if it can be completed with a dependent load/store [1]. [1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2 Cc: stable@vger.kernel.org Signed-off-by:
Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by:
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Gustavo A. R. Silva authored
There is a potential NULL pointer dereference in case kzalloc() fails and returns NULL. Fix this by adding a NULL check on *session* Also, update the function header with information about the expected return on failure and remove unnecessary variable rc. This issue was detected with the help of Coccinelle. Fixes: 0eca353e ("misc: IBM Virtual Management Channel Driver (VMC)") Cc: stable@vger.kernel.org Signed-off-by:
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Wei Yongjun authored
Fix to return a negative error code -ENOMEM from the new_inode() and d_make_root() error handling cases instead of 0, as done elsewhere in this function. Fixes: 849d540d ("binderfs: implement "max" mount option") Signed-off-by:
Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by:
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- 13 Jan, 2019 3 commits
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Tomas Winkler authored
Add the Denverton innovation engine (IE) device ids. The IE is an ME-like device which provides HW security offloading. Cc: <stable@vger.kernel.org> Signed-off-by:
Tomas Winkler <tomas.winkler@intel.com> Signed-off-by:
Alexander Usyskin <alexander.usyskin@intel.com> Signed-off-by:
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Alexander Usyskin authored
The LBG server platform sports DMA support. Cc: <stable@vger.kernel.org> #v5.0+ Signed-off-by:
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Tomas Winkler authored
Not all FW versions support DMA on their first release, hence it is normal behavior to receive a reject response upon DMA setup request. In order to prevent confusion, the DMA setup reject message is printed only in debug level. Cc: <stable@vger.kernel.org> #v5.0+ Signed-off-by:
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- 12 Jan, 2019 1 commit
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Christian Brauner authored
kbuild reported a build faile in [1]. This is triggered when CONFIG_IPC_NS is not set. So let's make the use of init_ipc_ns conditional on CONFIG_IPC_NS being set. [1]: https://lists.01.org/pipermail/kbuild-all/2019-January/056903.htmlSigned-off-by:
Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by:
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- 11 Jan, 2019 4 commits
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Greg Kroah-Hartman authored
Merge tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux into char-misc-linus Sasha writes: Three bug fixes for different parts of the hyper-v code: - Fix for a lockup when changing NIC's MTU from Dexuan. - Fix of use of uninitialized memory from Dexuan. - Fix for memory corruption caused by ballooning from Vitaly. All 3 were tested internally. * tag 'hyperv-fixes-signed' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: vmbus: fix subchannel removal hv_balloon: avoid touching uninitialized struct page during tail onlining Drivers: hv: vmbus: Check for ring when getting debug info
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Christian Brauner authored
The binderfs instance in the initial ipc namespace will always have a reserve of 4 binder devices unless explicitly capped by specifying a lower value via the "max" mount option. This ensures when binder devices are removed (on accident or on purpose) they can always be recreated without risking that all minor numbers have already been used up. Cc: Todd Kjos <tkjos@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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Christian Brauner authored
It doesn't make sense to call the header binder_ctl.h when its sole existence is tied to binderfs. So give it a sensible name. Users will far more easily remember binderfs.h than binder_ctl.h. Signed-off-by:
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Christian Brauner authored
Since binderfs can be mounted by userns root in non-initial user namespaces some precautions are in order. First, a way to set a maximum on the number of binder devices that can be allocated per binderfs instance and second, a way to reserve a reasonable chunk of binderfs devices for the initial ipc namespace. A first approach as seen in [1] used sysctls similiar to devpts but was shown to be flawed (cf. [2] and [3]) since some aspects were unneeded. This is an alternative approach which avoids sysctls completely and instead switches to a single mount option. Starting with this commit binderfs instances can be mounted with a limit on the number of binder devices that can be allocated. The max=<count> mount option serves as a per-instance limit. If max=<count> is set then only <count> number of binder devices can be allocated in this binderfs instance. This allows to safely bind-mount binderfs instances into unprivileged user namespaces since userns root in a non-initial user namespace cannot change the mount option as long as it does not own the mount namespace the binderfs mount was created in and hence cannot drain the host of minor device numbers [1]: https://lore.kernel.org/lkml/20181221133909.18794-1-christian@brauner.io/ [2]; https://lore.kernel.org/lkml/20181221163316.GA8517@kroah.com/ [3]: https://lore.kernel.org/lkml/CAHRSSEx+gDVW4fKKK8oZNAir9G5icJLyodO8hykv3O0O1jt2FQ@mail.gmail.com/ [4]: https://lore.kernel.org/lkml/20181221192044.5yvfnuri7gdop4rs@brauner.io/ Cc: Todd Kjos <tkjos@google.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by:
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- 10 Jan, 2019 1 commit
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Dexuan Cui authored
The changes to split ring allocation from open/close, broke the cleanup of subchannels. This resulted in problems using uio on network devices because the subchannel was left behind when the network device was unbound. The cause was in the disconnect logic which used list splice to move the subchannel list into a local variable. This won't work because the subchannel list is needed later during the process of the rescind messages (relid2channel). The fix is to just leave the subchannel list in place which is what the original code did. The list is cleaned up later when the host rescind is processed. Without the fix, we have a lot of "hang" issues in netvsc when we try to change the NIC's MTU, set the number of channels, etc. Fixes: ae6935ed ("vmbus: split ring buffer allocation from open") Cc: stable@vger.kernel.org Signed-off-by:
Stephen Hemminger <sthemmin@microsoft.com> Signed-off-by:
Dexuan Cui <decui@microsoft.com> Signed-off-by:
Sasha Levin <sashal@kernel.org>
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- 09 Jan, 2019 2 commits
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Vitaly Kuznetsov authored
Hyper-V memory hotplug protocol has 2M granularity and in Linux x86 we use 128M. To deal with it we implement partial section onlining by registering custom page onlining callback (hv_online_page()). Later, when more memory arrives we try to online the 'tail' (see hv_bring_pgs_online()). It was found that in some cases this 'tail' onlining causes issues: BUG: Bad page state in process kworker/0:2 pfn:109e3a page:ffffe08344278e80 count:0 mapcount:1 mapping:0000000000000000 index:0x0 flags: 0xfffff80000000() raw: 000fffff80000000 dead000000000100 dead000000000200 0000000000000000 raw: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 page dumped because: nonzero mapcount ... Workqueue: events hot_add_req [hv_balloon] Call Trace: dump_stack+0x5c/0x80 bad_page.cold.112+0x7f/0xb2 free_pcppages_bulk+0x4b8/0x690 free_unref_page+0x54/0x70 hv_page_online_one+0x5c/0x80 [hv_balloon] hot_add_req.cold.24+0x182/0x835 [hv_balloon] ... Turns out that we now have deferred struct page initialization for memory hotplug so e.g. memory_block_action() in drivers/base/memory.c does pages_correctly_probed() check and in that check it avoids inspecting struct pages and checks sections instead. But in Hyper-V balloon driver we do PageReserved(pfn_to_page()) check and this is now wrong. Switch to checking online_section_nr() instead. Signed-off-by:
Vitaly Kuznetsov <vkuznets@redhat.com> Cc: stable@kernel.org Signed-off-by:
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Dexuan Cui authored
fc96df16 is good and can already fix the "return stack garbage" issue, but let's also improve hv_ringbuffer_get_debuginfo(), which would silently return stack garbage, if people forget to check channel->state or ring_info->ring_buffer, when using the function in the future. Having an error check in the function would eliminate the potential risk. Add a Fixes tag to indicate the patch depdendency. Fixes: fc96df16 ("Drivers: hv: vmbus: Return -EINVAL for the sys files for unopened channels") Cc: stable@vger.kernel.org Cc: K. Y. Srinivasan <kys@microsoft.com> Cc: Haiyang Zhang <haiyangz@microsoft.com> Signed-off-by:
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- 08 Jan, 2019 2 commits
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Christian Brauner authored
When currently mounting binderfs in the same ipc namespace twice: mount -t binder binder /A mount -t binder binder /B then the binderfs instances mounted on /A and /B will be the same, i.e. they will have the same superblock. This was the first approach that seemed reasonable. However, this leads to some problems and inconsistencies: /* private binderfs instance in same ipc namespace */ There is no way for a user to request a private binderfs instance in the same ipc namespace. This request has been made in a private mail to me by two independent people. /* bind-mounts */ If users want the same binderfs instance to appear in multiple places they can use bind mounts. So there is no value in having a request for a new binderfs mount giving them the same instance. /* unexpected behavior */ It's surprising that request to mount binderfs is not giving the user a new instance like tmpfs, devpts, ramfs, and others do. /* past mistakes */ Other pseudo-filesystems once made the same mistakes of giving back the same superblock when actually requesting a new mount (cf. devpts's deprecated "newinstance" option). We should not make the same mistake. Once we've committed to always giving back the same superblock in the same IPC namespace with the next kernel release we will not be able to make that change so better to do it now. /* kdbusfs */ It was pointed out to me that kdbusfs - which is conceptually closely related to binderfs - also allowed users to get a private kdbusfs instance in the same IPC namespace by making each mount of kdbusfs a separate instance. I think that makes a lot of sense. Signed-off-by:
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Christian Brauner authored
The binderfs filesystem never needs to be mounted by the kernel itself. This is conceptually wrong and should never have been done in the first place. Fixes: 3ad20fe3 ("binder: implement binderfs") Signed-off-by:
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- 07 Jan, 2019 3 commits
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuildLinus Torvalds authored
Pull more Kbuild updates from Masahiro Yamada: - improve boolinit.cocci and use_after_iter.cocci semantic patches - fix alignment for kallsyms - move 'asm goto' compiler test to Kconfig and clean up jump_label CONFIG option - generate asm-generic wrappers automatically if arch does not implement mandatory UAPI headers - remove redundant generic-y defines - misc cleanups * tag 'kbuild-v4.21-3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: kconfig: rename generated .*conf-cfg to *conf-cfg kbuild: remove unnecessary stubs for archheader and archscripts kbuild: use assignment instead of define ... endef for filechk_* rules arch: remove redundant UAPI generic-y defines kbuild: generate asm-generic wrappers if mandatory headers are missing arch: remove stale comments "UAPI Header export list" riscv: remove redundant kernel-space generic-y kbuild: change filechk to surround the given command with { } kbuild: remove redundant target cleaning on failure kbuild: clean up rule_dtc_dt_yaml kbuild: remove UIMAGE_IN and UIMAGE_OUT jump_label: move 'asm goto' support test to Kconfig kallsyms: lower alignment on ARM scripts: coccinelle: boolinit: drop warnings on named constants scripts: coccinelle: check for redeclaration kconfig: remove unused "file" field of yylval union nds32: remove redundant kernel-space generic-y nios2: remove unneeded HAS_DMA define
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
Pull perf tooling updates form Ingo Molnar: "A final batch of perf tooling changes: mostly fixes and small improvements" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (29 commits) perf session: Add comment for perf_session__register_idle_thread() perf thread-stack: Fix thread stack processing for the idle task perf thread-stack: Allocate an array of thread stacks perf thread-stack: Factor out thread_stack__init() perf thread-stack: Allow for a thread stack array perf thread-stack: Avoid direct reference to the thread's stack perf thread-stack: Tidy thread_stack__bottom() usage perf thread-stack: Simplify some code in thread_stack__process() tools gpio: Allow overriding CFLAGS tools power turbostat: Override CFLAGS assignments and add LDFLAGS to build command tools thermal tmon: Allow overriding CFLAGS assignments tools power x86_energy_perf_policy: Override CFLAGS assignments and add LDFLAGS to build command perf c2c: Increase the HITM ratio limit for displayed cachelines perf c2c: Change the default coalesce setup perf trace beauty ioctl: Beautify USBDEVFS_ commands perf trace beauty: Export function to get the files for a thread perf trace: Wire up ioctl's USBDEBFS_ cmd table generator perf beauty ioctl: Add generator for USBDEVFS_ ioctl commands tools headers uapi: Grab a copy of usbdevice_fs.h perf trace: Store the major number for a file when storing its pathname ...
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- 06 Jan, 2019 11 commits
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Linus Torvalds authored
The semantics of what "in core" means for the mincore() system call are somewhat unclear, but Linux has always (since 2.3.52, which is when mincore() was initially done) treated it as "page is available in page cache" rather than "page is mapped in the mapping". The problem with that traditional semantic is that it exposes a lot of system cache state that it really probably shouldn't, and that users shouldn't really even care about. So let's try to avoid that information leak by simply changing the semantics to be that mincore() counts actual mapped pages, not pages that might be cheaply mapped if they were faulted (note the "might be" part of the old semantics: being in the cache doesn't actually guarantee that you can access them without IO anyway, since things like network filesystems may have to revalidate the cache before use). In many ways the old semantics were somewhat insane even aside from the information leak issue. From the very beginning (and that beginning is a long time ago: 2.3.52 was released in March 2000, I think), the code had a comment saying Later we can get more picky about what "in core" means precisely. and this is that "later". Admittedly it is much later than is really comfortable. NOTE! This is a real semantic change, and it is for example known to change the output of "fincore", since that program literally does a mmmap without populating it, and then doing "mincore()" on that mapping that doesn't actually have any pages in it. I'm hoping that nobody actually has any workflow that cares, and the info leak is real. We may have to do something different if it turns out that people have valid reasons to want the old semantics, and if we can limit the information leak sanely. Cc: Kevin Easton <kevin@guarana.org> Cc: Jiri Kosina <jikos@kernel.org> Cc: Masatake YAMATO <yamato@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Signed-off-by:Linus Torvalds <torvalds@linux-foundation.org>
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Linus Torvalds authored
Commit 594cc251 ("make 'user_access_begin()' do 'access_ok()'") broke both alpha and SH booting in qemu, as noticed by Guenter Roeck. It turns out that the bug wasn't actually in that commit itself (which would have been surprising: it was mostly a no-op), but in how the addition of access_ok() to the strncpy_from_user() and strnlen_user() functions now triggered the case where those functions would test the access of the very last byte of the user address space. The string functions actually did that user range test before too, but they did it manually by just comparing against user_addr_max(). But with user_access_begin() doing the check (using "access_ok()"), it now exposed problems in the architecture implementations of that function. For example, on alpha, the access_ok() helper macro looked like this: #define __access_ok(addr, size) \ ((get_fs().seg & (addr | size | (addr+size))) == 0) and what it basically tests is of any of the high bits get set (the USER_DS masking value is 0xfffffc0000000000). And that's completely wrong for the "addr+size" check. Because it's off-by-one for the case where we check to the very end of the user address space, which is exactly what the strn*_user() functions do. Why? Because "addr+size" will be exactly the size of the address space, so trying to access the last byte of the user address space will fail the __access_ok() check, even though it shouldn't. As a result, the user string accessor functions failed consistently - because they literally don't know how long the string is going to be, and the max access is going to be that last byte of the user address space. Side note: that alpha macro is buggy for another reason too - it re-uses the arguments twice. And SH has another version of almost the exact same bug: #define __addr_ok(addr) \ ((unsigned long __force)(addr) < current_thread_info()->addr_limit.seg) so far so good: yes, a user address must be below the limit. But then: #define __access_ok(addr, size) \ (__addr_ok((addr) + (size))) is wrong with the exact same off-by-one case: the case when "addr+size" is exactly _equal_ to the limit is actually perfectly fine (think "one byte access at the last address of the user address space") The SH version is actually seriously buggy in another way: it doesn't actually check for overflow, even though it did copy the _comment_ that talks about overflow. So it turns out that both SH and alpha actually have completely buggy implementations of access_ok(), but they happened to work in practice (although the SH overflow one is a serious serious security bug, not that anybody likely cares about SH security). This fixes the problems by using a similar macro on both alpha and SH. It isn't trying to be clever, the end address is based on this logic: unsigned long __ao_end = __ao_a + __ao_b - !!__ao_b; which basically says "add start and length, and then subtract one unless the length was zero". We can't subtract one for a zero length, or we'd just hit an underflow instead. For a lot of access_ok() users the length is a constant, so this isn't actually as expensive as it initially looks. Reported-and-tested-by:
Guenter Roeck <linux@roeck-us.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Signed-off-by:
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscryptLinus Torvalds authored
Pull fscrypt updates from Ted Ts'o: "Add Adiantum support for fscrypt" * tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: fscrypt: add Adiantum support
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4Linus Torvalds authored
Pull ext4 bug fixes from Ted Ts'o: "Fix a number of ext4 bugs" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix special inode number checks in __ext4_iget() ext4: track writeback errors using the generic tracking infrastructure ext4: use ext4_write_inode() when fsyncing w/o a journal ext4: avoid kernel warning when writing the superblock to a dead device ext4: fix a potential fiemap/page fault deadlock w/ inline_data ext4: make sure enough credits are reserved for dioread_nolock writes
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git://git.infradead.org/users/hch/dma-mappingLinus Torvalds authored
Pull dma-mapping fixes from Christoph Hellwig: "Fix various regressions introduced in this cycles: - fix dma-debug tracking for the map_page / map_single consolidatation - properly stub out DMA mapping symbols for !HAS_DMA builds to avoid link failures - fix AMD Gart direct mappings - setup the dma address for no kernel mappings using the remap allocator" * tag 'dma-mapping-4.21-1' of git://git.infradead.org/users/hch/dma-mapping: dma-direct: fix DMA_ATTR_NO_KERNEL_MAPPING for remapped allocations x86/amd_gart: fix unmapping of non-GART mappings dma-mapping: remove a few unused exports dma-mapping: properly stub out the DMA API for !CONFIG_HAS_DMA dma-mapping: remove dmam_{declare,release}_coherent_memory dma-mapping: implement dmam_alloc_coherent using dmam_alloc_attrs dma-mapping: implement dma_map_single_attrs using dma_map_page_attrs -
Linus Torvalds authored
Merge tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform Pull chrome platform updates from Benson Leung: - Changes for EC_MKBP_EVENT_SENSOR_FIFO handling. - Also, maintainership changes. Olofj out, Enric balletbo in. * tag 'tag-chrome-platform-for-v4.21' of git://git.kernel.org/pub/scm/linux/kernel/git/bleung/chrome-platform: MAINTAINERS: add maintainers for ChromeOS EC sub-drivers MAINTAINERS: platform/chrome: Add Enric as a maintainer MAINTAINERS: platform/chrome: remove myself as maintainer platform/chrome: don't report EC_MKBP_EVENT_SENSOR_FIFO as wakeup platform/chrome: straighten out cros_ec_get_{next,host}_event() error codes
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git://github.com/andersson/remoteprocLinus Torvalds authored
Pull hwspinlock updates from Bjorn Andersson: "This adds support for the hardware semaphores found in STM32MP1" * tag 'hwlock-v4.21' of git://github.com/andersson/remoteproc: hwspinlock: fix return value check in stm32_hwspinlock_probe() hwspinlock: add STM32 hwspinlock device dt-bindings: hwlock: Document STM32 hwspinlock bindings
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Eric Biggers authored
Add support for the Adiantum encryption mode to fscrypt. Adiantum is a tweakable, length-preserving encryption mode with security provably reducible to that of XChaCha12 and AES-256, subject to a security bound. It's also a true wide-block mode, unlike XTS. See the paper "Adiantum: length-preserving encryption for entry-level processors" (https://eprint.iacr.org/2018/720.pdf) for more details. Also see commit 059c2a4d ("crypto: adiantum - add Adiantum support"). On sufficiently long messages, Adiantum's bottlenecks are XChaCha12 and the NH hash function. These algorithms are fast even on processors without dedicated crypto instructions. Adiantum makes it feasible to enable storage encryption on low-end mobile devices that lack AES instructions; currently such devices are unencrypted. On ARM Cortex-A7, on 4096-byte messages Adiantum encryption is about 4 times faster than AES-256-XTS encryption; decryption is about 5 times faster. In fscrypt, Adiantum is suitable for encrypting both file contents and names. With filenames, it fixes a known weakness: when two filenames in a directory share a common prefix of >= 16 bytes, with CTS-CBC their encrypted filenames share a common prefix too, leaking information. Adiantum does not have this problem. Since Adiantum also accepts long tweaks (IVs), it's also safe to use the master key directly for Adiantum encryption rather than deriving per-file keys, provided that the per-file nonce is included in the IVs and the master key isn't used for any other encryption mode. This configuration saves memory and improves performance. A new fscrypt policy flag is added to allow users to opt-in to this configuration. Signed-off-by:
Eric Biggers <ebiggers@google.com> Signed-off-by:
Theodore Ts'o <tytso@mit.edu>
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git://git.lwn.net/linuxLinus Torvalds authored
Pull documentation fixes from Jonathan Corbet: "A handful of late-arriving documentation fixes" * tag 'docs-5.0-fixes' of git://git.lwn.net/linux: doc: filesystems: fix bad references to nonexistent ext4.rst file Documentation/admin-guide: update URL of LKML information link Docs/kernel-api.rst: Remove blk-tag.c reference
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git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394Linus Torvalds authored
Pull firewire fixlet from Stefan Richter: "Remove an explicit dependency in Kconfig which is implied by another dependency" * tag 'firewire-update' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394: firewire: Remove depends on HAS_DMA in case of platform dependency
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git://git.kernel.dk/linux-blockLinus Torvalds authored
Pull block updates and fixes from Jens Axboe: - Pulled in MD changes that Shaohua had queued up for 4.21. Unfortunately we lost Shaohua late 2018, I'm sending these in on his behalf. - In conjunction with the above, I added a CREDITS entry for Shaoua. - sunvdc queue restart fix (Ming) * tag 'for-linus-20190104' of git://git.kernel.dk/linux-block: Add CREDITS entry for Shaohua Li block: sunvdc: don't run hw queue synchronously from irq context md: fix raid10 hang issue caused by barrier raid10: refactor common wait code from regular read/write request md: remvoe redundant condition check lib/raid6: add option to skip algo benchmarking lib/raid6: sort algos in rough performance order lib/raid6: check for assembler SSSE3 support lib/raid6: avoid __attribute_const__ redefinition lib/raid6: add missing include for raid6test md: remove set but not used variable 'bi_rdev'
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