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2016-01-22wrappers for ->i_mutex accessAl Viro
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: "Embarrassing braino fix + pipe page accounting + fixing an eyesore in find_filesystem() (checking that s1 is equal to prefix of s2 of given length can be done in many ways, but "compare strlen(s1) with length and then do strncmp()" is not a good one...)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: [regression] fix braino in fs/dlm/user.c pipe: limit the per-user amount of pages allocated in pipes find_filesystem(): simplify comparison
2016-01-21Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge third patch-bomb from Andrew Morton: "I'm pretty much done for -rc1 now: - the rest of MM, basically - lib/ updates - checkpatch, epoll, hfs, fatfs, ptrace, coredump, exit - cpu_mask simplifications - kexec, rapidio, MAINTAINERS etc, etc. - more dma-mapping cleanups/simplifications from hch" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (109 commits) MAINTAINERS: add/fix git URLs for various subsystems mm: memcontrol: add "sock" to cgroup2 memory.stat mm: memcontrol: basic memory statistics in cgroup2 memory controller mm: memcontrol: do not uncharge old page in page cache replacement Documentation: cgroup: add memory.swap.{current,max} description mm: free swap cache aggressively if memcg swap is full mm: vmscan: do not scan anon pages if memcg swap limit is hit swap.h: move memcg related stuff to the end of the file mm: memcontrol: replace mem_cgroup_lruvec_online with mem_cgroup_online mm: vmscan: pass memcg to get_scan_count() mm: memcontrol: charge swap to cgroup2 mm: memcontrol: clean up alloc, online, offline, free functions mm: memcontrol: flatten struct cg_proto mm: memcontrol: rein in the CONFIG space madness net: drop tcp_memcontrol.c mm: memcontrol: introduce CONFIG_MEMCG_LEGACY_KMEM mm: memcontrol: allow to disable kmem accounting for cgroup2 mm: memcontrol: account "kmem" consumers in cgroup2 memory controller mm: memcontrol: move kmem accounting code to CONFIG_MEMCG mm: memcontrol: separate kmem code from legacy tcp accounting code ...
2016-01-21Merge tag 'pci-v4.5-changes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci Pull PCI updates from Bjorn Helgaas: "PCI changes for the v4.5 merge window: Enumeration: - Simplify config space size computation (Bjorn Helgaas) - Avoid iterating through ROM outside the resource window (Edward O'Callaghan) - Support PCIe devices with short cfg_size (Jason S. McMullan) - Add Netronome vendor and device IDs (Jason S. McMullan) - Limit config space size for Netronome NFP6000 family (Jason S. McMullan) - Add Netronome NFP4000 PF device ID (Simon Horman) - Limit config space size for Netronome NFP4000 (Simon Horman) - Print warnings for all invalid expansion ROM headers (Vladis Dronov) Resource management: - Fix minimum allocation address overwrite (Christoph Biedl) PCI device hotplug: - acpiphp_ibm: Fix null dereferences on null ibm_slot (Colin Ian King) - pciehp: Always protect pciehp_disable_slot() with hotplug mutex (Guenter Roeck) - shpchp: Constify hpc_ops structure (Julia Lawall) - ibmphp: Remove unneeded NULL test (Julia Lawall) Power management: - Make ASPM sysfs link_state_store() consistent with link_state_show() (Andy Lutomirski) Virtualization - Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183 (Tim Sander) MSI: - Remove empty pci_msi_init_pci_dev() (Bjorn Helgaas) - Mark PCIe/PCI (MSI) IRQ cascade handlers as IRQF_NO_THREAD (Grygorii Strashko) - Initialize MSI capability for all architectures (Guilherme G. Piccoli) - Relax msi_domain_alloc() to support parentless MSI irqdomains (Liu Jiang) ARM Versatile host bridge driver: - Remove unused pci_sys_data structures (Lorenzo Pieralisi) Broadcom iProc host bridge driver: - Hide CONFIG_PCIE_IPROC (Arnd Bergmann) - Do not use 0x in front of %pap (Dmitry V. Krivenok) - Update iProc PCIe device tree binding (Ray Jui) - Add PAXC interface support (Ray Jui) - Add iProc PCIe MSI device tree binding (Ray Jui) - Add iProc PCIe MSI support (Ray Jui) Freescale i.MX6 host bridge driver: - Use gpio_set_value_cansleep() (Fabio Estevam) - Add support for active-low reset GPIO (Petr Štetiar) HiSilicon host bridge driver: - Add support for HiSilicon Hip06 PCIe host controllers (Gabriele Paoloni) Intel VMD host bridge driver: - Export irq_domain_set_info() for module use (Keith Busch) - x86/PCI: Allow DMA ops specific to a PCI domain (Keith Busch) - Use 32 bit PCI domain numbers (Keith Busch) - Add driver for Intel Volume Management Device (VMD) (Keith Busch) Qualcomm host bridge driver: - Document PCIe devicetree bindings (Stanimir Varbanov) - Add Qualcomm PCIe controller driver (Stanimir Varbanov) - dts: apq8064: add PCIe devicetree node (Stanimir Varbanov) - dts: ifc6410: enable PCIe DT node for this board (Stanimir Varbanov) Renesas R-Car host bridge driver: - Add support for R-Car H3 to pcie-rcar (Harunobu Kurokawa) - Allow DT to override default window settings (Phil Edworthy) - Convert to DT resource parsing API (Phil Edworthy) - Revert "PCI: rcar: Build pcie-rcar.c only on ARM" (Phil Edworthy) - Remove unused pci_sys_data struct from pcie-rcar (Phil Edworthy) - Add runtime PM support to pcie-rcar (Phil Edworthy) - Add Gen2 PHY setup to pcie-rcar (Phil Edworthy) - Add gen2 fallback compatibility string for pci-rcar-gen2 (Simon Horman) - Add gen2 fallback compatibility string for pcie-rcar (Simon Horman) Synopsys DesignWare host bridge driver: - Simplify control flow (Bjorn Helgaas) - Make config accessor override checking symmetric (Bjorn Helgaas) - Ensure ATU is enabled before IO/conf space accesses (Stanimir Varbanov) Miscellaneous: - Add of_pci_get_host_bridge_resources() stub (Arnd Bergmann) - Check for PCI_HEADER_TYPE_BRIDGE equality, not bitmask (Bjorn Helgaas) - Fix all whitespace issues (Bogicevic Sasa) - x86/PCI: Simplify pci_bios_{read,write} (Geliang Tang) - Use to_pci_dev() instead of open-coding it (Geliang Tang) - Use kobj_to_dev() instead of open-coding it (Geliang Tang) - Use list_for_each_entry() to simplify code (Geliang Tang) - Fix typos in <linux/msi.h> (Thomas Petazzoni) - x86/PCI: Clarify AMD Fam10h config access restrictions comment (Tomasz Nowicki)" * tag 'pci-v4.5-changes' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci: (58 commits) PCI: Add function 1 DMA alias quirk for Lite-On/Plextor M6e/Marvell 88SS9183 PCI: Limit config space size for Netronome NFP4000 PCI: Add Netronome NFP4000 PF device ID x86/PCI: Add driver for Intel Volume Management Device (VMD) PCI/AER: Use 32 bit PCI domain numbers x86/PCI: Allow DMA ops specific to a PCI domain irqdomain: Export irq_domain_set_info() for module use PCI: host: Add of_pci_get_host_bridge_resources() stub genirq/MSI: Relax msi_domain_alloc() to support parentless MSI irqdomains PCI: rcar: Add Gen2 PHY setup to pcie-rcar PCI: rcar: Add runtime PM support to pcie-rcar PCI: designware: Make config accessor override checking symmetric PCI: ibmphp: Remove unneeded NULL test ARM: dts: ifc6410: enable PCIe DT node for this board ARM: dts: apq8064: add PCIe devicetree node PCI: hotplug: Use list_for_each_entry() to simplify code PCI: rcar: Remove unused pci_sys_data struct from pcie-rcar PCI: hisi: Add support for HiSilicon Hip06 PCIe host controllers PCI: Avoid iterating through memory outside the resource window PCI: acpiphp_ibm: Fix null dereferences on null ibm_slot ...
2016-01-21Merge tag 'pm+acpi-4.5-rc1-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull more power management and ACPI updates from Rafael Wysocki: "This includes fixes on top of the previous batch of PM+ACPI updates and some new material as well. From the new material perspective the most significant are the driver core changes that should allow USB devices to stay suspended over system suspend/resume cycles if they have been runtime-suspended already beforehand. Apart from that, ACPICA is updated to upstream revision 20160108 (cosmetic mostly, but including one fixup on top of the previous ACPICA update) and there are some devfreq updates the didn't make it before (due to timing). A few recent regressions are fixed, most importantly in the cpuidle menu governor and in the ACPI backlight driver and some x86 platform drivers depending on it. Some more bugs are fixed and cleanups are made on top of that. Specifics: - Modify the driver core and the USB subsystem to allow USB devices to stay suspended over system suspend/resume cycles if they have been runtime-suspended already beforehand and fix some bugs on top of these changes (Tomeu Vizoso, Rafael Wysocki). - Update ACPICA to upstream revision 20160108, including updates of the ACPICA's copyright notices, a code fixup resulting from a regression fix that was necessary in the upstream code only (the regression fixed by it has never been present in Linux) and a compiler warning fix (Bob Moore, Lv Zheng). - Fix a recent regression in the cpuidle menu governor that broke it on practically all architectures other than x86 and make a couple of optimizations on top of that fix (Rafael Wysocki). - Clean up the selection of cpuidle governors depending on whether or not the kernel is configured for tickless systems (Jean Delvare). - Revert a recent commit that introduced a regression in the ACPI backlight driver, address the problem it attempted to fix in a different way and revert one more cosmetic change depending on the problematic commit (Hans de Goede). - Add two more ACPI backlight quirks (Hans de Goede). - Fix a few minor problems in the core devfreq code, clean it up a bit and update the MAINTAINERS information related to it (Chanwoo Choi, MyungJoo Ham). - Improve an error message in the ACPI fan driver (Andy Lutomirski). - Fix a recent build regression in the cpupower tool (Shreyas Prabhu)" * tag 'pm+acpi-4.5-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (32 commits) cpuidle: menu: Avoid pointless checks in menu_select() sched / idle: Drop default_idle_call() fallback from call_cpuidle() cpupower: Fix build error in cpufreq-info cpuidle: Don't enable all governors by default cpuidle: Default to ladder governor on ticking systems time: nohz: Expose tick_nohz_enabled ACPICA: Update version to 20160108 ACPICA: Silence a -Wbad-function-cast warning when acpi_uintptr_t is 'uintptr_t' ACPICA: Additional 2016 copyright changes ACPICA: Reduce regression fix divergence from upstream ACPICA ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Satellite R830 ACPI / video: Revert "thinkpad_acpi: Use acpi_video_handles_brightness_key_presses()" ACPI / video: Document acpi_video_handles_brightness_key_presses() a bit ACPI / video: Fix using an uninitialized mutex / list_head in acpi_video_handles_brightness_key_presses() ACPI / video: Revert "ACPI / video: driver must be registered before checking for keypresses" ACPI / fan: Improve acpi_device_update_power error message ACPI / video: Add disable_backlight_sysfs_if quirk for the Toshiba Portege R700 cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0 MAINTAINERS: Add devfreq-event entry MAINTAINERS: Add missing git repository and directory for devfreq ...
2016-01-21prctl: take mmap sem for writing to protect against othersMateusz Guzik
An unprivileged user can trigger an oops on a kernel with CONFIG_CHECKPOINT_RESTORE. proc_pid_cmdline_read takes mmap_sem for reading and obtains args + env start/end values. These get sanity checked as follows: BUG_ON(arg_start > arg_end); BUG_ON(env_start > env_end); These can be changed by prctl_set_mm. Turns out also takes the semaphore for reading, effectively rendering it useless. This results in: kernel BUG at fs/proc/base.c:240! invalid opcode: 0000 [#1] SMP Modules linked in: virtio_net CPU: 0 PID: 925 Comm: a.out Not tainted 4.4.0-rc8-next-20160105dupa+ #71 Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 task: ffff880077a68000 ti: ffff8800784d0000 task.ti: ffff8800784d0000 RIP: proc_pid_cmdline_read+0x520/0x530 RSP: 0018:ffff8800784d3db8 EFLAGS: 00010206 RAX: ffff880077c5b6b0 RBX: ffff8800784d3f18 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 00007f78e8857000 RDI: 0000000000000246 RBP: ffff8800784d3e40 R08: 0000000000000008 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000001 R12: 0000000000000050 R13: 00007f78e8857800 R14: ffff88006fcef000 R15: ffff880077c5b600 FS: 00007f78e884a740(0000) GS:ffff88007b200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b CR2: 00007f78e8361770 CR3: 00000000790a5000 CR4: 00000000000006f0 Call Trace: __vfs_read+0x37/0x100 vfs_read+0x82/0x130 SyS_read+0x58/0xd0 entry_SYSCALL_64_fastpath+0x12/0x76 Code: 4c 8b 7d a8 eb e9 48 8b 9d 78 ff ff ff 4c 8b 7d 90 48 8b 03 48 39 45 a8 0f 87 f0 fe ff ff e9 d1 fe ff ff 4c 8b 7d 90 eb c6 0f 0b <0f> 0b 0f 0b 66 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 RIP proc_pid_cmdline_read+0x520/0x530 ---[ end trace 97882617ae9c6818 ]--- Turns out there are instances where the code just reads aformentioned values without locking whatsoever - namely environ_read and get_cmdline. Interestingly these functions look quite resilient against bogus values, but I don't believe this should be relied upon. The first patch gets rid of the oops bug by grabbing mmap_sem for writing. The second patch is optional and puts locking around aformentioned consumers for safety. Consumers of other fields don't seem to benefit from similar treatment and are left untouched. This patch (of 2): The code was taking the semaphore for reading, which does not protect against readers nor concurrent modifications. The problem could cause a sanity checks to fail in procfs's cmdline reader, resulting in an OOPS. Note that some functions perform an unlocked read of various mm fields, but they seem to be fine despite possible modificaton. Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Acked-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jarod Wilson <jarod@redhat.com> Cc: Jan Stancek <jstancek@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Anshuman Khandual <anshuman.linux@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kernel: printk: specify alignment for struct printk_logAndrey Ryabinin
On architectures that have support for efficient unaligned access struct printk_log has 4-byte alignment. Specify alignment attribute in type declaration. The whole point of this patch is to fix deadlock which happening when UBSAN detects unaligned access in printk() thus UBSAN recursively calls printk() with logbuf_lock held by top printk() call. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Randy Dunlap <rdunlap@infradead.org> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Yury Gribov <y.gribov@samsung.com> Cc: Dmitry Vyukov <dvyukov@google.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Kostya Serebryany <kcc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21sysctl: enable strict writesKees Cook
SYSCTL_WRITES_WARN was added in commit f4aacea2f5d1 ("sysctl: allow for strict write position handling"), and released in v3.16 in August of 2014. Since then I can find only 1 instance of non-zero offset writing[1], and it was fixed immediately in CRIU[2]. As such, it appears safe to flip this to the strict state now. [1] https://www.google.com/search?q="when%20file%20position%20was%20not%200" [2] http://lists.openvz.org/pipermail/criu/2015-April/019819.html Signed-off-by: Kees Cook <keescook@chromium.org> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kexec: move some memembers and definitions within the scope of CONFIG_KEXEC_FILEXunlei Pang
Move the stuff currently only used by the kexec file code within CONFIG_KEXEC_FILE (and CONFIG_KEXEC_VERIFY_SIG). Also move internal "struct kexec_sha_region" and "struct kexec_buf" into "kexec_internal.h". Signed-off-by: Xunlei Pang <xlpang@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Dave Young <dyoung@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kernel/kexec_core.c: use list_for_each_entry_safe in kimage_free_page_listGeliang Tang
Use list_for_each_entry_safe() instead of list_for_each_safe() to simplify the code. Signed-off-by: Geliang Tang <geliangtang@163.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kexec: set KEXEC_TYPE_CRASH before sanity_check_segment_list()Xunlei Pang
sanity_check_segment_list() checks KEXEC_TYPE_CRASH flag to ensure all the segments of the loaded crash kernel are within the kernel crash resource limits, so set the flag beforehand. Signed-off-by: Xunlei Pang <xlpang@redhat.com> Acked-by: Dave Young <dyoung@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Acked-by: Baoquan He <bhe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kernel/cpu.c: make set_cpu_* static inlinesRasmus Villemoes
Almost all callers of the set_cpu_* functions pass an explicit true or false. Making them static inline thus replaces the function calls with a simple set_bit/clear_bit, saving some .text. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kernel/cpu.c: eliminate cpu_*_maskRasmus Villemoes
Replace the variables cpu_possible_mask, cpu_online_mask, cpu_present_mask and cpu_active_mask with macros expanding to expressions of the same type and value, eliminating some indirection. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kernel/cpu.c: export __cpu_*_maskRasmus Villemoes
Exporting the cpumasks __cpu_possible_mask and friends will allow us to remove the extra indirection through the cpu_*_mask variables. It will also allow the set_cpu_* functions to become static inlines, which will give a .text reduction. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21kernel/cpu.c: change type of cpu_possible_bits and friendsRasmus Villemoes
Change cpu_possible_bits and friends (online, present, active) from being bitmaps that happen to have the right size to actually being struct cpumasks. Also rename them to __cpu_xyz_mask. This is mostly a small cleanup in preparation for exporting them and, eventually, eliminating the extra indirection through the cpu_xyz_mask variables. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21exit: remove unneeded declaration of exit_mm()Dmitry Safonov
Signed-off-by: Dmitry Safonov <0x7f454c46@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21ptrace: use fsuid, fsgid, effective creds for fs access checksJann Horn
By checking the effective credentials instead of the real UID / permitted capabilities, ensure that the calling process actually intended to use its credentials. To ensure that all ptrace checks use the correct caller credentials (e.g. in case out-of-tree code or newly added code omits the PTRACE_MODE_*CREDS flag), use two new flags and require one of them to be set. The problem was that when a privileged task had temporarily dropped its privileges, e.g. by calling setreuid(0, user_uid), with the intent to perform following syscalls with the credentials of a user, it still passed ptrace access checks that the user would not be able to pass. While an attacker should not be able to convince the privileged task to perform a ptrace() syscall, this is a problem because the ptrace access check is reused for things in procfs. In particular, the following somewhat interesting procfs entries only rely on ptrace access checks: /proc/$pid/stat - uses the check for determining whether pointers should be visible, useful for bypassing ASLR /proc/$pid/maps - also useful for bypassing ASLR /proc/$pid/cwd - useful for gaining access to restricted directories that contain files with lax permissions, e.g. in this scenario: lrwxrwxrwx root root /proc/13020/cwd -> /root/foobar drwx------ root root /root drwxr-xr-x root root /root/foobar -rw-r--r-- root root /root/foobar/secret Therefore, on a system where a root-owned mode 6755 binary changes its effective credentials as described and then dumps a user-specified file, this could be used by an attacker to reveal the memory layout of root's processes or reveal the contents of files he is not allowed to access (through /proc/$pid/cwd). [akpm@linux-foundation.org: fix warning] Signed-off-by: Jann Horn <jann@thejh.net> Acked-by: Kees Cook <keescook@chromium.org> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge.hallyn@ubuntu.com> Cc: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Cc: Andy Lutomirski <luto@kernel.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21ptrace: task_stopped_code(ptrace => true) can't see TASK_STOPPED taskOleg Nesterov
task_stopped_code()->task_is_stopped_or_traced() doesn't look right, the traced task must never be TASK_STOPPED. We can not add WARN_ON(task_is_stopped(p)), but this is only because do_wait() can race with PTRACE_ATTACH from another thread. [akpm@linux-foundation.org: teeny cleanup] Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Roland McGrath <roland@hack.frob.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Pedro Alves <palves@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-21ptrace: make wait_on_bit(JOBCTL_TRAPPING_BIT) in ptrace_attach() killableOleg Nesterov
ptrace_attach() can hang waiting for STOPPED -> TRACED transition if the tracee gets frozen in between, change wait_on_bit() to use TASK_KILLABLE. This doesn't really solve the problem(s) and we probably need to fix the freezer. In particular, note that this means that pm freezer will fail if it races attach-to-stopped-task. And otoh perhaps we can just remove JOBCTL_TRAPPING_BIT altogether, it is not clear if we really need to hide this transition from debugger, WNOHANG after PTRACE_ATTACH can fail anyway if it races with SIGCONT. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reported-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Roland McGrath <roland@hack.frob.com> Acked-by: Tejun Heo <tj@kernel.org> Cc: Pedro Alves <palves@redhat.com> Cc: Jan Kratochvil <jan.kratochvil@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-20Merge branch 'pm-cpuidle'Rafael J. Wysocki
* pm-cpuidle: cpuidle: menu: Avoid pointless checks in menu_select() sched / idle: Drop default_idle_call() fallback from call_cpuidle() cpuidle: Don't enable all governors by default cpuidle: Default to ladder governor on ticking systems time: nohz: Expose tick_nohz_enabled cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0
2016-01-20pipe: limit the per-user amount of pages allocated in pipesWilly Tarreau
On no-so-small systems, it is possible for a single process to cause an OOM condition by filling large pipes with data that are never read. A typical process filling 4000 pipes with 1 MB of data will use 4 GB of memory. On small systems it may be tricky to set the pipe max size to prevent this from happening. This patch makes it possible to enforce a per-user soft limit above which new pipes will be limited to a single page, effectively limiting them to 4 kB each, as well as a hard limit above which no new pipes may be created for this user. This has the effect of protecting the system against memory abuse without hurting other users, and still allowing pipes to work correctly though with less data at once. The limit are controlled by two new sysctls : pipe-user-pages-soft, and pipe-user-pages-hard. Both may be disabled by setting them to zero. The default soft limit allows the default number of FDs per process (1024) to create pipes of the default size (64kB), thus reaching a limit of 64MB before starting to create only smaller pipes. With 256 processes limited to 1024 FDs each, this results in 1024*64kB + (256*1024 - 1024) * 4kB = 1084 MB of memory allocated for a user. The hard limit is disabled by default to avoid breaking existing applications that make intensive use of pipes (eg: for splicing). Reported-by: socketpair@gmail.com Reported-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Mitigates: CVE-2013-4312 (Linux 2.0+) Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-19sched / idle: Drop default_idle_call() fallback from call_cpuidle()Rafael J. Wysocki
After commit 9c4b2867ed7c (cpuidle: menu: Fix menu_select() for CPUIDLE_DRIVER_STATE_START == 0) it is clear that menu_select() cannot return negative values. Moreover, ladder_select_state() will never return a negative value too, so make find_deepest_state() return non-negative values too and drop the default_idle_call() fallback from call_cpuidle(). This eliminates one branch from the idle loop and makes the governors and find_deepest_state() handle the case when all states have been disabled from sysfs consistently. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Ingo Molnar <mingo@kernel.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com>
2016-01-18Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: - EVM gains support for loading an x509 cert from the kernel (EVM_LOAD_X509), into the EVM trusted kernel keyring. - Smack implements 'file receive' process-based permission checking for sockets, rather than just depending on inode checks. - Misc enhancments for TPM & TPM2. - Cleanups and bugfixes for SELinux, Keys, and IMA. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (41 commits) selinux: Inode label revalidation performance fix KEYS: refcount bug fix ima: ima_write_policy() limit locking IMA: policy can be updated zero times selinux: rate-limit netlink message warnings in selinux_nlmsg_perm() selinux: export validatetrans decisions gfs2: Invalid security labels of inodes when they go invalid selinux: Revalidate invalid inode security labels security: Add hook to invalidate inode security labels selinux: Add accessor functions for inode->i_security security: Make inode argument of inode_getsecid non-const security: Make inode argument of inode_getsecurity non-const selinux: Remove unused variable in selinux_inode_init_security keys, trusted: seal with a TPM2 authorization policy keys, trusted: select hash algorithm for TPM2 chips keys, trusted: fix: *do not* allow duplicate key options tpm_ibmvtpm: properly handle interrupted packet receptions tpm_tis: Tighten IRQ auto-probing tpm_tis: Refactor the interrupt setup tpm_tis: Get rid of the duplicate IRQ probing code ...
2016-01-18Merge branch 'upstream' of git://git.infradead.org/users/pcmoore/auditLinus Torvalds
Pull audit updates from Paul Moore: "Seven audit patches for 4.5, all very minor despite the diffstat. The diffstat churn for linux/audit.h can be attributed to needing to reshuffle the linux/audit.h header to fix the seccomp auditing issue (see the commit description for details). Besides the seccomp/audit fix, most of the fixes are around trying to improve the connection with the audit daemon and a Kconfig simplification. Nothing crazy, and everything passes our little audit-testsuite" * 'upstream' of git://git.infradead.org/users/pcmoore/audit: audit: always enable syscall auditing when supported and audit is enabled audit: force seccomp event logging to honor the audit_enabled flag audit: Delete unnecessary checks before two function calls audit: wake up threads if queue switched from limited to unlimited audit: include auditd's threads in audit_log_start() wait exception audit: remove audit_backlog_wait_overflow audit: don't needlessly reset valid wait time
2016-01-17Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge second patch-bomb from Andrew Morton: - more MM stuff: - Kirill's page-flags rework - Kirill's now-allegedly-fixed THP rework - MADV_FREE implementation - DAX feature work (msync/fsync). This isn't quite complete but DAX is new and it's good enough and the guys have a handle on what needs to be done - I expect this to be wrapped in the next week or two. - some vsprintf maintenance work - various other misc bits * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (145 commits) printk: change recursion_bug type to bool lib/vsprintf: factor out %pN[F] handler as netdev_bits() lib/vsprintf: refactor duplicate code to special_hex_number() printk-formats.txt: remove unimplemented %pT printk: help pr_debug and pr_devel to optimize out arguments lib/test_printf.c: test dentry printing lib/test_printf.c: add test for large bitmaps lib/test_printf.c: account for kvasprintf tests lib/test_printf.c: add a few number() tests lib/test_printf.c: test precision quirks lib/test_printf.c: check for out-of-bound writes lib/test_printf.c: don't BUG lib/kasprintf.c: add sanity check to kvasprintf lib/vsprintf.c: warn about too large precisions and field widths lib/vsprintf.c: help gcc make number() smaller lib/vsprintf.c: expand field_width to 24 bits lib/vsprintf.c: eliminate potential race in string() lib/vsprintf.c: move string() below widen_string() lib/vsprintf.c: pull out padding code from dentry_name() printk: do cond_resched() between lines while outputting to consoles ...
2016-01-17Merge tag 'sound-4.5-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull sound updates from Takashi Iwai: "We've had quite busy weeks in this cycle. Looking at ALSA core, the significant changes are a few fixes wrt timer and sequencer ioctls that have been revealed by fuzzer recently. Other than that, ASoC core got a few updates about DAI link handling, but these are rather straightforward refactoring. In drivers scene, ASoC received quite lots of new drivers in addition to bunch of updates for still ongoing Intel Skylake support and topology API. HD-audio gained a new HDMI/DP hotplug notification via component. FireWire got a pile of code refactoring/updates with SCS.1x driver integration. More highlights are shown below. [ NOTE: this contains also many commits for DRM. This is due to the pull of drm stable branch into sound tree, as the base of i915 audio component work for HD-audio. The highlights below don't contain these DRM changes, as these are supposed to be pulled via drm tree in anyway sooner or later. ] Core: - Handful fixes to harden ALSA timer and sequencer ioctls against races reported by syzkaller fuzzer - Irq description string can be unique to each card; only for HD-audio for now ASoC: - Conversion of the array of DAI links to a list for supporting dynamically adding and removing DAI links - Topology API enhancements to make everything more component based and being able to specify PCM links via topology - Some more fixes for the topology code, though it is still not final and ready for enabling in production; we really need to get to the point where that can be done - A pile of changes for Intel SkyLake drivers which hopefully deliver some useful initial functionality for systems with this chipset, though there is more work still to come - Lots of new features and cleanups for the Renesas drivers - ANC support for WM5110 - New drivers: Imagination Technologies IPs, Atmel class D speaker, Cirrus CS47L24 and WM1831, Dialog DA7128, Realtek RT5659 and RT56156, Rockchip RK3036, TI PC3168A, and AMD ACP - Rename PCM1792a driver to be generic pcm179x HD-Audio: - Use audio component for i915 HDMI/DP hotplug handling - On-demand binding with i915 driver - bdl_pos_adj parameter adjustment for Baytrail controllers - Enable power_save_node for CX20722; this shouldn't lead to regression, hopefully - Kabylake HDMI/DP codec support - Quirks for Lenovo E50-80, Dell Latitude E-series, and other Dell machines - A few code refactoring FireWire: - Lots of code cleanup and refactoring - Integrate the support of SCS.1x devices into snd-oxfw driver; snd-scs1x driver is obsoleted USB-audio: - Fix possible NULL dereference at disconnection - A regression fix for Native Instruments devices Misc: - A few code cleanups of fm801 driver" * tag 'sound-4.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: (722 commits) ALSA: timer: Code cleanup ALSA: timer: Harden slave timer list handling ALSA: hda - Add fixup for Dell Latitidue E6540 ALSA: timer: Fix race among timer ioctls ALSA: hda - add codec support for Kabylake display audio codec ALSA: timer: Fix double unlink of active_list ALSA: usb-audio: Fix mixer ctl regression of Native Instrument devices ALSA: hda - fix the headset mic detection problem for a Dell laptop ALSA: hda - Fix white noise on Dell Latitude E5550 ALSA: hda_intel: add card number to irq description ALSA: seq: Fix race at timer setup and close ALSA: seq: Fix missing NULL check at remove_events ioctl ALSA: usb-audio: Avoid calling usb_autopm_put_interface() at disconnect ASoC: hdac_hdmi: remove unused hdac_hdmi_query_pin_connlist ASoC: AMD: Add missing include file ALSA: hda - Fixup inverted internal mic for Lenovo E50-80 ALSA: usb: Add native DSD support for Oppo HA-1 ASoC: Make aux_dev more like a generic component ASoC: bcm2835: cleanup includes by ordering them alphabetically ASoC: AMD: Manage ACP 2.x SRAM banks power ...
2016-01-16printk: change recursion_bug type to boolSergey Senozhatsky
`recursion_bug' is used as recursion_bug toggle, so make it `bool'. Signed-off-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16printk: do cond_resched() between lines while outputting to consolesTejun Heo
@console_may_schedule tracks whether console_sem was acquired through lock or trylock. If the former, we're inside a sleepable context and console_conditional_schedule() performs cond_resched(). This allows console drivers which use console_lock for synchronization to yield while performing time-consuming operations such as scrolling. However, the actual console outputting is performed while holding irq-safe logbuf_lock, so console_unlock() clears @console_may_schedule before starting outputting lines. Also, only a few drivers call console_conditional_schedule() to begin with. This means that when a lot of lines need to be output by console_unlock(), for example on a console registration, the task doing console_unlock() may not yield for a long time on a non-preemptible kernel. If this happens with a slow console devices, for example a serial console, the outputting task may occupy the cpu for a very long time. Long enough to trigger softlockup and/or RCU stall warnings, which in turn pile more messages, sometimes enough to trigger the next cycle of warnings incapacitating the system. Fix it by making console_unlock() insert cond_resched() between lines if @console_may_schedule. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Calvin Owens <calvinowens@fb.com> Acked-by: Jan Kara <jack@suse.com> Cc: Dave Jones <davej@codemonkey.org.uk> Cc: Kyle McMartin <kyle@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>
2016-01-16printk: only unregister boot consoles when necessaryThierry Reding
Boot consoles are typically replaced by proper consoles during the boot process. This can be problematic if the boot console data is part of the init section that is reclaimed late during boot. If the proper console does not register before this point in time, the boot console will need to be removed (so that the freed memory is not accessed), leaving the system without output for some time. There are various reasons why the proper console may not register early enough, such as deferred probe or the driver being a loadable module. If that happens, there is some amount of time where no console messages are visible to the user, which in turn can mean that they won't see crashes or other potentially useful information. To avoid this situation, only remove the boot console when it resides in the init section. Code exists to replace the boot console by the proper console when it is registered, keeping a seamless transition between the boot and proper consoles. Signed-off-by: Thierry Reding <treding@nvidia.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16kernel/stop_machine.c: remove CONFIG_SMP dependenciesAndrew Morton
stop_machine.o is only built if CONFIG_SMP=y, so this ifdef always evaluates to true. [akpm@linux-foundation.org: remove now-unneeded ifdef] Reported-by: Valentin Rothberg <valentinrothberg@gmail.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Ingo Molnar <mingo@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm: bring in additional flag for fixup_user_fault to signal unlockDominik Dingel
During Jason's work with postcopy migration support for s390 a problem regarding gmap faults was discovered. The gmap code will call fixup_user_fault which will end up always in handle_mm_fault. Till now we never cared about retries, but as the userfaultfd code kind of relies on it. this needs some fix. This patchset does not take care of the futex code. I will now look closer at this. This patch (of 2): With the introduction of userfaultfd, kvm on s390 needs fixup_user_fault to pass in FAULT_FLAG_ALLOW_RETRY and give feedback if during the faulting we ever unlocked mmap_sem. This patch brings in the logic to handle retries as well as it cleans up the current documentation. fixup_user_fault was not having the same semantics as filemap_fault. It never indicated if a retry happened and so a caller wasn't able to handle that case. So we now changed the behaviour to always retry a locked mmap_sem. Signed-off-by: Dominik Dingel <dingel@linux.vnet.ibm.com> Reviewed-by: Andrea Arcangeli <aarcange@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: "Jason J. Herne" <jjherne@linux.vnet.ibm.com> Cc: David Rientjes <rientjes@google.com> Cc: Eric B Munson <emunson@akamai.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Dominik Dingel <dingel@linux.vnet.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm, x86: get_user_pages() for dax mappingsDan Williams
A dax mapping establishes a pte with _PAGE_DEVMAP set when the driver has established a devm_memremap_pages() mapping, i.e. when the pfn_t return from ->direct_access() has PFN_DEV and PFN_MAP set. Later, when encountering _PAGE_DEVMAP during a page table walk we lookup and pin a struct dev_pagemap instance to keep the result of pfn_to_page() valid until put_page(). Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Logan Gunthorpe <logang@deltatee.com> Cc: Dave Hansen <dave@sr71.net> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm, dax, pmem: introduce {get|put}_dev_pagemap() for dax-gupDan Williams
get_dev_page() enables paths like get_user_pages() to pin a dynamically mapped pfn-range (devm_memremap_pages()) while the resulting struct page objects are in use. Unlike get_page() it may fail if the device is, or is in the process of being, disabled. While the initial lookup of the range may be an expensive list walk, the result is cached to speed up subsequent lookups which are likely to be in the same mapped range. devm_memremap_pages() now requires a reference counter to be specified at init time. For pmem this means moving request_queue allocation into pmem_alloc() so the existing queue usage counter can track "device pages". ZONE_DEVICE pages always have an elevated count and will never be on an lru reclaim list. That space in 'struct page' can be redirected for other uses, but for safety introduce a poison value that will always trip __list_add() to assert. This allows half of the struct list_head storage to be reclaimed with some assurance to back up the assumption that the page count never goes to zero and a list_add() is never attempted. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Logan Gunthorpe <logang@deltatee.com> Cc: Dave Hansen <dave@sr71.net> Cc: Matthew Wilcox <willy@linux.intel.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16x86, mm: introduce vmem_altmap to augment vmemmap_populate()Dan Williams
In support of providing struct page for large persistent memory capacities, use struct vmem_altmap to change the default policy for allocating memory for the memmap array. The default vmemmap_populate() allocates page table storage area from the page allocator. Given persistent memory capacities relative to DRAM it may not be feasible to store the memmap in 'System Memory'. Instead vmem_altmap represents pre-allocated "device pages" to satisfy vmemmap_alloc_block_buf() requests. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Reported-by: kbuild test robot <lkp@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm: introduce find_dev_pagemap()Dan Williams
There are several scenarios where we need to retrieve and update metadata associated with a given devm_memremap_pages() mapping, and the only lookup key available is a pfn in the range: 1/ We want to augment vmemmap_populate() (called via arch_add_memory()) to allocate memmap storage from pre-allocated pages reserved by the device driver. At vmemmap_alloc_block_buf() time it grabs device pages rather than page allocator pages. This is in support of devm_memremap_pages() mappings where the memmap is too large to fit in main memory (i.e. large persistent memory devices). 2/ Taking a reference against the mapping when inserting device pages into the address_space radix of a given inode. This facilitates unmap_mapping_range() and truncate_inode_pages() operations when the driver is tearing down the mapping. 3/ get_user_pages() operations on ZONE_DEVICE memory require taking a reference against the mapping so that the driver teardown path can revoke and drain usage of device pages. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Tested-by: Logan Gunthorpe <logang@deltatee.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Chinner <david@fromorbit.com> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16mm, dax, pmem: introduce pfn_tDan Williams
For the purpose of communicating the optional presence of a 'struct page' for the pfn returned from ->direct_access(), introduce a type that encapsulates a page-frame-number plus flags. These flags contain the historical "page_link" encoding for a scatterlist entry, but can also denote "device memory". Where "device memory" is a set of pfns that are not part of the kernel's linear mapping by default, but are accessed via the same memory controller as ram. The motivation for this new type is large capacity persistent memory that needs struct page entries in the 'memmap' to support 3rd party DMA (i.e. O_DIRECT I/O with a persistent memory source/target). However, we also need it in support of maintaining a list of mapped inodes which need to be unmapped at driver teardown or freeze_bdev() time. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Dave Hansen <dave@sr71.net> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16futex, thp: remove special case for THP in get_futex_keyKirill A. Shutemov
With new THP refcounting, we don't need tricks to stabilize huge page. If we've got reference to tail page, it can't split under us. This patch effectively reverts a5b338f2b0b1 ("thp: update futex compound knowledge"). Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Tested-by: Artem Savkov <artem.savkov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-16memcg: adjust to support new THP refcountingKirill A. Shutemov
As with rmap, with new refcounting we cannot rely on PageTransHuge() to check if we need to charge size of huge page form the cgroup. We need to get information from caller to know whether it was mapped with PMD or PTE. We do uncharge when last reference on the page gone. At that point if we see PageTransHuge() it means we need to unchange whole huge page. The tricky part is partial unmap -- when we try to unmap part of huge page. We don't do a special handing of this situation, meaning we don't uncharge the part of huge page unless last user is gone or split_huge_page() is triggered. In case of cgroup memory pressure happens the partial unmapped page will be split through shrinker. This should be good enough. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.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>
2016-01-16rmap: add argument to charge compound pageKirill A. Shutemov
We're going to allow mapping of individual 4k pages of THP compound page. It means we cannot rely on PageTransHuge() check to decide if map/unmap small page or THP. The patch adds new argument to rmap functions to indicate whether we want to operate on whole compound page or only the small page. [n-horiguchi@ah.jp.nec.com: fix mapcount mismatch in hugepage migration] Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Tested-by: Sasha Levin <sasha.levin@oracle.com> Tested-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Jerome Marchand <jmarchan@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Cc: Steve Capper <steve.capper@linaro.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Christoph Lameter <cl@linux.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15time: nohz: Expose tick_nohz_enabledJean Delvare
The cpuidle subsystem needs it. Signed-off-by: Jean Delvare <jdelvare@suse.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-15irqdomain: Export irq_domain_set_info() for module useKeith Busch
Export irq_domain_set_info() for module use. It will be used by the Volume Management Device driver. [bhelgaas: changelog] Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-15Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge first patch-bomb from Andrew Morton: - A few hotfixes which missed 4.4 becasue I was asleep. cc'ed to -stable - A few misc fixes - OCFS2 updates - Part of MM. Including pretty large changes to page-flags handling and to thp management which have been buffered up for 2-3 cycles now. I have a lot of MM material this time. [ It turns out the THP part wasn't quite ready, so that got dropped from this series - Linus ] * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (117 commits) zsmalloc: reorganize struct size_class to pack 4 bytes hole mm/zbud.c: use list_last_entry() instead of list_tail_entry() zram/zcomp: do not zero out zcomp private pages zram: pass gfp from zcomp frontend to backend zram: try vmalloc() after kmalloc() zram/zcomp: use GFP_NOIO to allocate streams mm: add tracepoint for scanning pages drivers/base/memory.c: fix kernel warning during memory hotplug on ppc64 mm/page_isolation: use macro to judge the alignment mm: fix noisy sparse warning in LIBCFS_ALLOC_PRE() mm: rework virtual memory accounting include/linux/memblock.h: fix ordering of 'flags' argument in comments mm: move lru_to_page to mm_inline.h Documentation/filesystems: describe the shared memory usage/accounting memory-hotplug: don't BUG() in register_memory_resource() hugetlb: make mm and fs code explicitly non-modular mm/swapfile.c: use list_for_each_entry_safe in free_swap_count_continuations mm: /proc/pid/clear_refs: no need to clear VM_SOFTDIRTY in clear_soft_dirty_pmd() mm: make sure isolate_lru_page() is never called for tail page vmstat: make vmstat_updater deferrable again and shut down on idle ...
2016-01-15Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching Pull livepatching updates from Jiri Kosina: - RO/NX attribute fixes for patch module relocations from Josh Poimboeuf. As part of this effort, module.c has been cleaned up as well and livepatching is piggy-backing on this cleanup. Rusty is OK with this whole lot going through livepatching tree. - symbol disambiguation support from Chris J Arges. That series is also Reviewed-by: Miroslav Benes <mbenes@suse.cz> but this came in only after I've alredy pushed out. Didn't want to rebase because of that, hence I am mentioning it here. - symbol lookup fix from Miroslav Benes * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/livepatching: livepatch: Cleanup module page permission changes module: keep percpu symbols in module's symtab module: clean up RO/NX handling. module: use a structure to encapsulate layout. gcov: use within_module() helper. module: Use the same logic for setting and unsetting RO/NX livepatch: function,sympos scheme in livepatch sysfs directory livepatch: add sympos as disambiguator field to klp_reloc livepatch: add old_sympos as disambiguator field to klp_func
2016-01-15mm: rework virtual memory accountingKonstantin Khlebnikov
When inspecting a vague code inside prctl(PR_SET_MM_MEM) call (which testing the RLIMIT_DATA value to figure out if we're allowed to assign new @start_brk, @brk, @start_data, @end_data from mm_struct) it's been commited that RLIMIT_DATA in a form it's implemented now doesn't do anything useful because most of user-space libraries use mmap() syscall for dynamic memory allocations. Linus suggested to convert RLIMIT_DATA rlimit into something suitable for anonymous memory accounting. But in this patch we go further, and the changes are bundled together as: * keep vma counting if CONFIG_PROC_FS=n, will be used for limits * replace mm->shared_vm with better defined mm->data_vm * account anonymous executable areas as executable * account file-backed growsdown/up areas as stack * drop struct file* argument from vm_stat_account * enforce RLIMIT_DATA for size of data areas This way code looks cleaner: now code/stack/data classification depends only on vm_flags state: VM_EXEC & ~VM_WRITE -> code (VmExe + VmLib in proc) VM_GROWSUP | VM_GROWSDOWN -> stack (VmStk) VM_WRITE & ~VM_SHARED & !stack -> data (VmData) The rest (VmSize - VmData - VmStk - VmExe - VmLib) could be called "shared", but that might be strange beast like readonly-private or VM_IO area. - RLIMIT_AS limits whole address space "VmSize" - RLIMIT_STACK limits stack "VmStk" (but each vma individually) - RLIMIT_DATA now limits "VmData" Signed-off-by: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Vegard Nossum <vegard.nossum@oracle.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Willy Tarreau <w@1wt.eu> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Kees Cook <keescook@google.com> Cc: Vladimir Davydov <vdavydov@virtuozzo.com> Cc: Pavel Emelyanov <xemul@virtuozzo.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15vmstat: make vmstat_updater deferrable again and shut down on idleChristoph Lameter
Currently the vmstat updater is not deferrable as a result of commit ba4877b9ca51 ("vmstat: do not use deferrable delayed work for vmstat_update"). This in turn can cause multiple interruptions of the applications because the vmstat updater may run at Make vmstate_update deferrable again and provide a function that folds the differentials when the processor is going to idle mode thus addressing the issue of the above commit in a clean way. Note that the shepherd thread will continue scanning the differentials from another processor and will reenable the vmstat workers if it detects any changes. Fixes: ba4877b9ca51 ("vmstat: do not use deferrable delayed work for vmstat_update") Signed-off-by: Christoph Lameter <cl@linux.com> Cc: Michal Hocko <mhocko@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm: mmap: add new /proc tunable for mmap_base ASLRDaniel Cashman
Address Space Layout Randomization (ASLR) provides a barrier to exploitation of user-space processes in the presence of security vulnerabilities by making it more difficult to find desired code/data which could help an attack. This is done by adding a random offset to the location of regions in the process address space, with a greater range of potential offset values corresponding to better protection/a larger search-space for brute force, but also to greater potential for fragmentation. The offset added to the mmap_base address, which provides the basis for the majority of the mappings for a process, is set once on process exec in arch_pick_mmap_layout() and is done via hard-coded per-arch values, which reflect, hopefully, the best compromise for all systems. The trade-off between increased entropy in the offset value generation and the corresponding increased variability in address space fragmentation is not absolute, however, and some platforms may tolerate higher amounts of entropy. This patch introduces both new Kconfig values and a sysctl interface which may be used to change the amount of entropy used for offset generation on a system. The direct motivation for this change was in response to the libstagefright vulnerabilities that affected Android, specifically to information provided by Google's project zero at: http://googleprojectzero.blogspot.com/2015/09/stagefrightened.html The attack presented therein, by Google's project zero, specifically targeted the limited randomness used to generate the offset added to the mmap_base address in order to craft a brute-force-based attack. Concretely, the attack was against the mediaserver process, which was limited to respawning every 5 seconds, on an arm device. The hard-coded 8 bits used resulted in an average expected success rate of defeating the mmap ASLR after just over 10 minutes (128 tries at 5 seconds a piece). With this patch, and an accompanying increase in the entropy value to 16 bits, the same attack would take an average expected time of over 45 hours (32768 tries), which makes it both less feasible and more likely to be noticed. The introduced Kconfig and sysctl options are limited by per-arch minimum and maximum values, the minimum of which was chosen to match the current hard-coded value and the maximum of which was chosen so as to give the greatest flexibility without generating an invalid mmap_base address, generally a 3-4 bits less than the number of bits in the user-space accessible virtual address space. When decided whether or not to change the default value, a system developer should consider that mmap_base address could be placed anywhere up to 2^(value) bits away from the non-randomized location, which would introduce variable-sized areas above and below the mmap_base address such that the maximum vm_area_struct size may be reduced, preventing very large allocations. This patch (of 4): ASLR only uses as few as 8 bits to generate the random offset for the mmap base address on 32 bit architectures. This value was chosen to prevent a poorly chosen value from dividing the address space in such a way as to prevent large allocations. This may not be an issue on all platforms. Allow the specification of a minimum number of bits so that platforms desiring greater ASLR protection may determine where to place the trade-off. Signed-off-by: Daniel Cashman <dcashman@google.com> Cc: Russell King <linux@arm.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Heinrich Schuchardt <xypron.glpk@gmx.de> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: David Rientjes <rientjes@google.com> Cc: Mark Salyzyn <salyzyn@android.com> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: Nick Kralevich <nnk@google.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Hector Marco-Gisbert <hecmargi@upv.es> Cc: Borislav Petkov <bp@suse.de> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15mm, shmem: add internal shmem resident memory accountingJerome Marchand
Currently looking at /proc/<pid>/status or statm, there is no way to distinguish shmem pages from pages mapped to a regular file (shmem pages are mapped to /dev/zero), even though their implication in actual memory use is quite different. The internal accounting currently counts shmem pages together with regular files. As a preparation to extend the userspace interfaces, this patch adds MM_SHMEMPAGES counter to mm_rss_stat to account for shmem pages separately from MM_FILEPAGES. The next patch will expose it to userspace - this patch doesn't change the exported values yet, by adding up MM_SHMEMPAGES to MM_FILEPAGES at places where MM_FILEPAGES was used before. The only user-visible change after this patch is the OOM killer message that separates the reported "shmem-rss" from "file-rss". [vbabka@suse.cz: forward-porting, tweak changelog] Signed-off-by: Jerome Marchand <jmarchan@redhat.com> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-15kmemcg: account certain kmem allocations to memcgVladimir Davydov
Mark those kmem allocations that are known to be easily triggered from userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to memcg. For the list, see below: - threadinfo - task_struct - task_delay_info - pid - cred - mm_struct - vm_area_struct and vm_region (nommu) - anon_vma and anon_vma_chain - signal_struct - sighand_struct - fs_struct - files_struct - fdtable and fdtable->full_fds_bits - dentry and external_name - inode for all filesystems. This is the most tedious part, because most filesystems overwrite the alloc_inode method. The list is far from complete, so feel free to add more objects. Nevertheless, it should be close to "account everything" approach and keep most workloads within bounds. Malevolent users will be able to breach the limit, but this was possible even with the former "account everything" approach (simply because it did not account everything in fact). [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Vladimir Davydov <vdavydov@virtuozzo.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Tejun Heo <tj@kernel.org> Cc: Greg Thelen <gthelen@google.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Cc: David Rientjes <rientjes@google.com> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-01-14genirq/MSI: Relax msi_domain_alloc() to support parentless MSI irqdomainsLiu Jiang
Previously msi_domain_alloc() assumed MSI irqdomains always had parent irqdomains, but that's not true for the new Intel VMD devices. Relax msi_domain_alloc() to support parentless MSI irqdomains. Signed-off-by: Jiang Liu <jiang.liu@linux.intel.com> Signed-off-by: Keith Busch <keith.busch@intel.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Thomas Gleixner <tglx@linutronix.de>
2016-01-14Merge tag 'libnvdimm-for-4.5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "The bulk of this has appeared in -next and independently received a build success notification from the kbuild robot. The 'for-4.5/block- dax' topic branch was rebased over the weekend to drop the "block device end-of-life" rework that Al would like to see re-implemented with a notifier, and to address bug reports against the badblocks integration. There is pending feedback against "libnvdimm: Add a poison list and export badblocks" received last week. Linda identified some localized fixups that we will handle incrementally. Summary: - Media error handling: The 'badblocks' implementation that originated in md-raid is up-levelled to a generic capability of a block device. This initial implementation is limited to being consulted in the pmem block-i/o path. Later, 'badblocks' will be consulted when creating dax mappings. - Raw block device dax: For virtualization and other cases that want large contiguous mappings of persistent memory, add the capability to dax-mmap a block device directly. - Increased /dev/mem restrictions: Add an option to treat all io-memory as IORESOURCE_EXCLUSIVE, i.e. disable /dev/mem access while a driver is actively using an address range. This behavior is controlled via the new CONFIG_IO_STRICT_DEVMEM option and can be overridden by the existing "iomem=relaxed" kernel command line option. - Miscellaneous fixes include a 'pfn'-device huge page alignment fix, block device shutdown crash fix, and other small libnvdimm fixes" * tag 'libnvdimm-for-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (32 commits) block: kill disk_{check|set|clear|alloc}_badblocks libnvdimm, pmem: nvdimm_read_bytes() badblocks support pmem, dax: disable dax in the presence of bad blocks pmem: fail io-requests to known bad blocks libnvdimm: convert to statically allocated badblocks libnvdimm: don't fail init for full badblocks list block, badblocks: introduce devm_init_badblocks block: clarify badblocks lifetime badblocks: rename badblocks_free to badblocks_exit libnvdimm, pmem: move definition of nvdimm_namespace_add_poison to nd.h libnvdimm: Add a poison list and export badblocks nfit_test: Enable DSMs for all test NFITs md: convert to use the generic badblocks code block: Add badblock management for gendisks badblocks: Add core badblock management code block: fix del_gendisk() vs blkdev_ioctl crash block: enable dax for raw block devices block: introduce bdev_file_inode() restrict /dev/mem to idle io memory ranges arch: consolidate CONFIG_STRICT_DEVM in lib/Kconfig.debug ...