bka
14 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Catalin Marinas
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aa5a358032 |
BACKPORT: arm64: Introduce prctl() options to control the tagged user addresses ABI
(Upstream commit 63f0c60379650d82250f22e4cf4137ef3dc4f43d). It is not desirable to relax the ABI to allow tagged user addresses into the kernel indiscriminately. This patch introduces a prctl() interface for enabling or disabling the tagged ABI with a global sysctl control for preventing applications from enabling the relaxed ABI (meant for testing user-space prctl() return error checking without reconfiguring the kernel). The ABI properties are inherited by threads of the same application and fork()'ed children but cleared on execve(). A Kconfig option allows the overall disabling of the relaxed ABI. The PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle MTE-specific settings like imprecise vs precise exceptions. Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Signed-off-by: Will Deacon <will@kernel.org> Change-Id: I2d52c5589b05415faab315c116245f1058d64750 Signed-off-by: Andrey Konovalov <andreyknvl@google.com> Bug: 135692346 |
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Greg Kroah-Hartman
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d142f569a1 |
Merge 4.14.86 into android-4.14
Changes in 4.14.86
mm/huge_memory: rename freeze_page() to unmap_page()
mm/huge_memory.c: reorder operations in __split_huge_page_tail()
mm/huge_memory: splitting set mapping+index before unfreeze
mm/huge_memory: fix lockdep complaint on 32-bit i_size_read()
mm/khugepaged: collapse_shmem() stop if punched or truncated
mm/khugepaged: fix crashes due to misaccounted holes
mm/khugepaged: collapse_shmem() remember to clear holes
mm/khugepaged: minor reorderings in collapse_shmem()
mm/khugepaged: collapse_shmem() without freezing new_page
mm/khugepaged: collapse_shmem() do not crash on Compound
media: em28xx: Fix use-after-free when disconnecting
ubi: Initialize Fastmap checkmapping correctly
libceph: store ceph_auth_handshake pointer in ceph_connection
libceph: factor out __prepare_write_connect()
libceph: factor out __ceph_x_decrypt()
libceph: factor out encrypt_authorizer()
libceph: add authorizer challenge
libceph: implement CEPHX_V2 calculation mode
bpf: Prevent memory disambiguation attack
tls: Add function to update the TLS socket configuration
tls: Fix TLS ulp context leak, when TLS_TX setsockopt is not used.
tls: Avoid copying crypto_info again after cipher_type check.
tls: don't override sk_write_space if tls_set_sw_offload fails.
tls: Use correct sk->sk_prot for IPV6
net/tls: Fixed return value when tls_complete_pending_work() fails
wil6210: missing length check in wmi_set_ie
btrfs: validate type when reading a chunk
btrfs: Verify that every chunk has corresponding block group at mount time
btrfs: Refactor check_leaf function for later expansion
btrfs: Check if item pointer overlaps with the item itself
btrfs: Add sanity check for EXTENT_DATA when reading out leaf
btrfs: Add checker for EXTENT_CSUM
btrfs: Move leaf and node validation checker to tree-checker.c
btrfs: tree-checker: Enhance btrfs_check_node output
btrfs: tree-checker: Fix false panic for sanity test
btrfs: tree-checker: Add checker for dir item
btrfs: tree-checker: use %zu format string for size_t
btrfs: tree-check: reduce stack consumption in check_dir_item
btrfs: tree-checker: Verify block_group_item
btrfs: tree-checker: Detect invalid and empty essential trees
btrfs: Check that each block group has corresponding chunk at mount time
btrfs: tree-checker: Check level for leaves and nodes
btrfs: tree-checker: Fix misleading group system information
f2fs: check blkaddr more accuratly before issue a bio
f2fs: sanity check on sit entry
f2fs: enhance sanity_check_raw_super() to avoid potential overflow
f2fs: clean up with is_valid_blkaddr()
f2fs: introduce and spread verify_blkaddr
f2fs: fix to do sanity check with secs_per_zone
f2fs: Add sanity_check_inode() function
f2fs: fix to do sanity check with extra_attr feature
f2fs: fix to do sanity check with user_block_count
f2fs: fix to do sanity check with node footer and iblocks
f2fs: fix to do sanity check with block address in main area
f2fs: fix to do sanity check with i_extra_isize
f2fs: fix to do sanity check with cp_pack_start_sum
xfs: don't fail when converting shortform attr to long form during ATTR_REPLACE
Revert "wlcore: Add missing PM call for wlcore_cmd_wait_for_event_or_timeout()"
net: skb_scrub_packet(): Scrub offload_fwd_mark
net: thunderx: set xdp_prog to NULL if bpf_prog_add fails
virtio-net: disable guest csum during XDP set
virtio-net: fail XDP set if guest csum is negotiated
net: thunderx: set tso_hdrs pointer to NULL in nicvf_free_snd_queue
packet: copy user buffers before orphan or clone
rapidio/rionet: do not free skb before reading its length
s390/qeth: fix length check in SNMP processing
usbnet: ipheth: fix potential recvmsg bug and recvmsg bug 2
sched/core: Fix cpu.max vs. cpuhotplug deadlock
x86/bugs: Add AMD's variant of SSB_NO
x86/bugs: Add AMD's SPEC_CTRL MSR usage
x86/bugs: Switch the selection of mitigation from CPU vendor to CPU features
x86/bugs: Update when to check for the LS_CFG SSBD mitigation
x86/bugs: Fix the AMD SSBD usage of the SPEC_CTRL MSR
x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation
x86/speculation: Apply IBPB more strictly to avoid cross-process data leak
x86/speculation: Propagate information about RSB filling mitigation to sysfs
x86/speculation: Add RETPOLINE_AMD support to the inline asm CALL_NOSPEC variant
x86/retpoline: Make CONFIG_RETPOLINE depend on compiler support
x86/retpoline: Remove minimal retpoline support
x86/speculation: Update the TIF_SSBD comment
x86/speculation: Clean up spectre_v2_parse_cmdline()
x86/speculation: Remove unnecessary ret variable in cpu_show_common()
x86/speculation: Move STIPB/IBPB string conditionals out of cpu_show_common()
x86/speculation: Disable STIBP when enhanced IBRS is in use
x86/speculation: Rename SSBD update functions
x86/speculation: Reorganize speculation control MSRs update
sched/smt: Make sched_smt_present track topology
x86/Kconfig: Select SCHED_SMT if SMP enabled
sched/smt: Expose sched_smt_present static key
x86/speculation: Rework SMT state change
x86/l1tf: Show actual SMT state
x86/speculation: Reorder the spec_v2 code
x86/speculation: Mark string arrays const correctly
x86/speculataion: Mark command line parser data __initdata
x86/speculation: Unify conditional spectre v2 print functions
x86/speculation: Add command line control for indirect branch speculation
x86/speculation: Prepare for per task indirect branch speculation control
x86/process: Consolidate and simplify switch_to_xtra() code
x86/speculation: Avoid __switch_to_xtra() calls
x86/speculation: Prepare for conditional IBPB in switch_mm()
ptrace: Remove unused ptrace_may_access_sched() and MODE_IBRS
x86/speculation: Split out TIF update
x86/speculation: Prevent stale SPEC_CTRL msr content
x86/speculation: Prepare arch_smt_update() for PRCTL mode
x86/speculation: Add prctl() control for indirect branch speculation
x86/speculation: Enable prctl mode for spectre_v2_user
x86/speculation: Add seccomp Spectre v2 user space protection mode
x86/speculation: Provide IBPB always command line options
kvm: mmu: Fix race in emulated page table writes
kvm: svm: Ensure an IBPB on all affected CPUs when freeing a vmcb
KVM: x86: Fix kernel info-leak in KVM_HC_CLOCK_PAIRING hypercall
KVM: X86: Fix scan ioapic use-before-initialization
xtensa: enable coprocessors that are being flushed
xtensa: fix coprocessor context offset definitions
xtensa: fix coprocessor part of ptrace_{get,set}xregs
Btrfs: ensure path name is null terminated at btrfs_control_ioctl
btrfs: relocation: set trans to be NULL after ending transaction
PCI: layerscape: Fix wrong invocation of outbound window disable accessor
arm64: dts: rockchip: Fix PCIe reset polarity for rk3399-puma-haikou.
x86/MCE/AMD: Fix the thresholding machinery initialization order
x86/fpu: Disable bottom halves while loading FPU registers
perf/x86/intel: Move branch tracing setup to the Intel-specific source file
perf/x86/intel: Add generic branch tracing check to intel_pmu_has_bts()
fs: fix lost error code in dio_complete
ALSA: wss: Fix invalid snd_free_pages() at error path
ALSA: ac97: Fix incorrect bit shift at AC97-SPSA control write
ALSA: control: Fix race between adding and removing a user element
ALSA: sparc: Fix invalid snd_free_pages() at error path
ALSA: hda/realtek - Support ALC300
ALSA: hda/realtek - fix headset mic detection for MSI MS-B171
ext2: fix potential use after free
ARM: dts: rockchip: Remove @0 from the veyron memory node
dmaengine: at_hdmac: fix memory leak in at_dma_xlate()
dmaengine: at_hdmac: fix module unloading
btrfs: release metadata before running delayed refs
staging: vchiq_arm: fix compat VCHIQ_IOC_AWAIT_COMPLETION
staging: rtl8723bs: Add missing return for cfg80211_rtw_get_station
USB: usb-storage: Add new IDs to ums-realtek
usb: core: quirks: add RESET_RESUME quirk for Cherry G230 Stream series
Revert "usb: dwc3: gadget: skip Set/Clear Halt when invalid"
iio:st_magn: Fix enable device after trigger
lib/test_kmod.c: fix rmmod double free
mm: use swp_offset as key in shmem_replace_page()
Drivers: hv: vmbus: check the creation_status in vmbus_establish_gpadl()
misc: mic/scif: fix copy-paste error in scif_create_remote_lookup
binder: fix race that allows malicious free of live buffer
libceph: weaken sizeof check in ceph_x_verify_authorizer_reply()
libceph: check authorizer reply/challenge length before reading
f2fs: fix missing up_read
Linux 4.14.86
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
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Thomas Gleixner
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6a847a6057 |
x86/speculation: Add prctl() control for indirect branch speculation
commit 9137bb27e60e554dab694eafa4cca241fa3a694f upstream Add the PR_SPEC_INDIRECT_BRANCH option for the PR_GET_SPECULATION_CTRL and PR_SET_SPECULATION_CTRL prctls to allow fine grained per task control of indirect branch speculation via STIBP and IBPB. Invocations: Check indirect branch speculation status with - prctl(PR_GET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, 0, 0, 0); Enable indirect branch speculation with - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_ENABLE, 0, 0); Disable indirect branch speculation with - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_DISABLE, 0, 0); Force disable indirect branch speculation with - prctl(PR_SET_SPECULATION_CTRL, PR_SPEC_INDIRECT_BRANCH, PR_SPEC_FORCE_DISABLE, 0, 0); See Documentation/userspace-api/spec_ctrl.rst. Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Jiri Kosina <jkosina@suse.cz> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Woodhouse <dwmw@amazon.co.uk> Cc: Andi Kleen <ak@linux.intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Casey Schaufler <casey.schaufler@intel.com> Cc: Asit Mallick <asit.k.mallick@intel.com> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Jon Masters <jcm@redhat.com> Cc: Waiman Long <longman9394@gmail.com> Cc: Greg KH <gregkh@linuxfoundation.org> Cc: Dave Stewart <david.c.stewart@intel.com> Cc: Kees Cook <keescook@chromium.org> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/20181125185005.866780996@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Greg Kroah-Hartman
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4c9e0a9b25 |
Merge 4.14.43 into android-4.14
Changes in 4.14.43
usbip: usbip_host: refine probe and disconnect debug msgs to be useful
usbip: usbip_host: delete device from busid_table after rebind
usbip: usbip_host: run rebind from exit when module is removed
usbip: usbip_host: fix NULL-ptr deref and use-after-free errors
usbip: usbip_host: fix bad unlock balance during stub_probe()
ALSA: usb: mixer: volume quirk for CM102-A+/102S+
ALSA: hda: Add Lenovo C50 All in one to the power_save blacklist
ALSA: control: fix a redundant-copy issue
spi: pxa2xx: Allow 64-bit DMA
spi: bcm-qspi: Avoid setting MSPI_CDRAM_PCS for spi-nor master
spi: bcm-qspi: Always read and set BSPI_MAST_N_BOOT_CTRL
KVM: arm/arm64: VGIC/ITS save/restore: protect kvm_read_guest() calls
KVM: arm/arm64: VGIC/ITS: protect kvm_read_guest() calls with SRCU lock
powerpc: Don't preempt_disable() in show_cpuinfo()
vfio: ccw: fix cleanup if cp_prefetch fails
tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all}
tee: shm: fix use-after-free via temporarily dropped reference
netfilter: nf_tables: free set name in error path
netfilter: nf_tables: can't fail after linking rule into active rule list
netfilter: nf_socket: Fix out of bounds access in nf_sk_lookup_slow_v{4,6}
i2c: designware: fix poll-after-enable regression
powerpc/powernv: Fix NVRAM sleep in invalid context when crashing
drm: Match sysfs name in link removal to link creation
lib/test_bitmap.c: fix bitmap optimisation tests to report errors correctly
radix tree: fix multi-order iteration race
mm: don't allow deferred pages with NEED_PER_CPU_KM
drm/i915/gen9: Add WaClearHIZ_WM_CHICKEN3 for bxt and glk
s390/qdio: fix access to uninitialized qdio_q fields
s390/cpum_sf: ensure sample frequency of perf event attributes is non-zero
s390/qdio: don't release memory in qdio_setup_irq()
s390: remove indirect branch from do_softirq_own_stack
x86/pkeys: Override pkey when moving away from PROT_EXEC
x86/pkeys: Do not special case protection key 0
efi: Avoid potential crashes, fix the 'struct efi_pci_io_protocol_32' definition for mixed mode
ARM: 8771/1: kprobes: Prohibit kprobes on do_undefinstr
x86/mm: Drop TS_COMPAT on 64-bit exec() syscall
tick/broadcast: Use for_each_cpu() specially on UP kernels
ARM: 8769/1: kprobes: Fix to use get_kprobe_ctlblk after irq-disabed
ARM: 8770/1: kprobes: Prohibit probing on optimized_callback
ARM: 8772/1: kprobes: Prohibit kprobes on get_user functions
Btrfs: fix xattr loss after power failure
Btrfs: send, fix invalid access to commit roots due to concurrent snapshotting
btrfs: property: Set incompat flag if lzo/zstd compression is set
btrfs: fix crash when trying to resume balance without the resume flag
btrfs: Split btrfs_del_delalloc_inode into 2 functions
btrfs: Fix delalloc inodes invalidation during transaction abort
btrfs: fix reading stale metadata blocks after degraded raid1 mounts
x86/nospec: Simplify alternative_msr_write()
x86/bugs: Concentrate bug detection into a separate function
x86/bugs: Concentrate bug reporting into a separate function
x86/bugs: Read SPEC_CTRL MSR during boot and re-use reserved bits
x86/bugs, KVM: Support the combination of guest and host IBRS
x86/bugs: Expose /sys/../spec_store_bypass
x86/cpufeatures: Add X86_FEATURE_RDS
x86/bugs: Provide boot parameters for the spec_store_bypass_disable mitigation
x86/bugs/intel: Set proper CPU features and setup RDS
x86/bugs: Whitelist allowed SPEC_CTRL MSR values
x86/bugs/AMD: Add support to disable RDS on Fam[15,16,17]h if requested
x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest
x86/speculation: Create spec-ctrl.h to avoid include hell
prctl: Add speculation control prctls
x86/process: Allow runtime control of Speculative Store Bypass
x86/speculation: Add prctl for Speculative Store Bypass mitigation
nospec: Allow getting/setting on non-current task
proc: Provide details on speculation flaw mitigations
seccomp: Enable speculation flaw mitigations
x86/bugs: Make boot modes __ro_after_init
prctl: Add force disable speculation
seccomp: Use PR_SPEC_FORCE_DISABLE
seccomp: Add filter flag to opt-out of SSB mitigation
seccomp: Move speculation migitation control to arch code
x86/speculation: Make "seccomp" the default mode for Speculative Store Bypass
x86/bugs: Rename _RDS to _SSBD
proc: Use underscores for SSBD in 'status'
Documentation/spec_ctrl: Do some minor cleanups
x86/bugs: Fix __ssb_select_mitigation() return type
x86/bugs: Make cpu_show_common() static
x86/bugs: Fix the parameters alignment and missing void
x86/cpu: Make alternative_msr_write work for 32-bit code
KVM: SVM: Move spec control call after restore of GS
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
x86/cpufeatures: Disentangle SSBD enumeration
x86/cpufeatures: Add FEATURE_ZEN
x86/speculation: Handle HT correctly on AMD
x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL
x86/speculation: Add virtualized speculative store bypass disable support
x86/speculation: Rework speculative_store_bypass_update()
x86/bugs: Unify x86_spec_ctrl_{set_guest,restore_host}
x86/bugs: Expose x86_spec_ctrl_base directly
x86/bugs: Remove x86_spec_ctrl_set()
x86/bugs: Rework spec_ctrl base and mask logic
x86/speculation, KVM: Implement support for VIRT_SPEC_CTRL/LS_CFG
KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD
x86/bugs: Rename SSBD_NO to SSB_NO
Linux 4.14.43
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
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Thomas Gleixner
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20d036a2e2 |
prctl: Add force disable speculation
commit 356e4bfff2c5489e016fdb925adbf12a1e3950ee upstream For certain use cases it is desired to enforce mitigations so they cannot be undone afterwards. That's important for loader stubs which want to prevent a child from disabling the mitigation again. Will also be used for seccomp(). The extra state preserving of the prctl state for SSB is a preparatory step for EBPF dymanic speculation control. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Thomas Gleixner
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33f6a06810 |
prctl: Add speculation control prctls
commit b617cfc858161140d69cc0b5cc211996b557a1c7 upstream
Add two new prctls to control aspects of speculation related vulnerabilites
and their mitigations to provide finer grained control over performance
impacting mitigations.
PR_GET_SPECULATION_CTRL returns the state of the speculation misfeature
which is selected with arg2 of prctl(2). The return value uses bit 0-2 with
the following meaning:
Bit Define Description
0 PR_SPEC_PRCTL Mitigation can be controlled per task by
PR_SET_SPECULATION_CTRL
1 PR_SPEC_ENABLE The speculation feature is enabled, mitigation is
disabled
2 PR_SPEC_DISABLE The speculation feature is disabled, mitigation is
enabled
If all bits are 0 the CPU is not affected by the speculation misfeature.
If PR_SPEC_PRCTL is set, then the per task control of the mitigation is
available. If not set, prctl(PR_SET_SPECULATION_CTRL) for the speculation
misfeature will fail.
PR_SET_SPECULATION_CTRL allows to control the speculation misfeature, which
is selected by arg2 of prctl(2) per task. arg3 is used to hand in the
control value, i.e. either PR_SPEC_ENABLE or PR_SPEC_DISABLE.
The common return values are:
EINVAL prctl is not implemented by the architecture or the unused prctl()
arguments are not 0
ENODEV arg2 is selecting a not supported speculation misfeature
PR_SET_SPECULATION_CTRL has these additional return values:
ERANGE arg3 is incorrect, i.e. it's not either PR_SPEC_ENABLE or PR_SPEC_DISABLE
ENXIO prctl control of the selected speculation misfeature is disabled
The first supported controlable speculation misfeature is
PR_SPEC_STORE_BYPASS. Add the define so this can be shared between
architectures.
Based on an initial patch from Tim Chen and mostly rewritten.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Colin Cross
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8392add7be |
ANDROID: mm: add a field to store names for private anonymous memory
Userspace processes often have multiple allocators that each do
anonymous mmaps to get memory. When examining memory usage of
individual processes or systems as a whole, it is useful to be
able to break down the various heaps that were allocated by
each layer and examine their size, RSS, and physical memory
usage.
This patch adds a user pointer to the shared union in
vm_area_struct that points to a null terminated string inside
the user process containing a name for the vma. vmas that
point to the same address will be merged, but vmas that
point to equivalent strings at different addresses will
not be merged.
Userspace can set the name for a region of memory by calling
prctl(PR_SET_VMA, PR_SET_VMA_ANON_NAME, start, len, (unsigned long)name);
Setting the name to NULL clears it.
The names of named anonymous vmas are shown in /proc/pid/maps
as [anon:<name>] and in /proc/pid/smaps in a new "Name" field
that is only present for named vmas. If the userspace pointer
is no longer valid all or part of the name will be replaced
with "<fault>".
The idea to store a userspace pointer to reduce the complexity
within mm (at the expense of the complexity of reading
/proc/pid/mem) came from Dave Hansen. This results in no
runtime overhead in the mm subsystem other than comparing
the anon_name pointers when considering vma merging. The pointer
is stored in a union with fieds that are only used on file-backed
mappings, so it does not increase memory usage.
Includes fix from Jed Davis <jld@mozilla.com> for typo in
prctl_set_vma_anon_name, which could attempt to set the name
across two vmas at the same time due to a typo, which might
corrupt the vma list. Fix it to use tmp instead of end to limit
the name setting to a single vma at a time.
Change-Id: I9aa7b6b5ef536cd780599ba4e2fba8ceebe8b59f
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
[AmitP: Fix get_user_pages_remote() call to align with upstream commit
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Greg Kroah-Hartman
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6f52b16c5b |
License cleanup: add SPDX license identifier to uapi header files with no license
Many user space API headers are missing licensing information, which makes it hard for compliance tools to determine the correct license. By default are files without license information under the default license of the kernel, which is GPLV2. Marking them GPLV2 would exclude them from being included in non GPLV2 code, which is obviously not intended. The user space API headers fall under the syscall exception which is in the kernels COPYING file: NOTE! This copyright does *not* cover user programs that use kernel services by normal system calls - this is merely considered normal use of the kernel, and does *not* fall under the heading of "derived work". otherwise syscall usage would not be possible. Update the files which contain no license information with an SPDX license identifier. The chosen identifier is 'GPL-2.0 WITH Linux-syscall-note' which is the officially assigned identifier for the Linux syscall exception. SPDX license identifiers are a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. See the previous patch in this series for the methodology of how this patch was researched. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
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Andy Lutomirski
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58319057b7 |
capabilities: ambient capabilities
Credit where credit is due: this idea comes from Christoph Lameter with a lot of valuable input from Serge Hallyn. This patch is heavily based on Christoph's patch. ===== The status quo ===== On Linux, there are a number of capabilities defined by the kernel. To perform various privileged tasks, processes can wield capabilities that they hold. Each task has four capability masks: effective (pE), permitted (pP), inheritable (pI), and a bounding set (X). When the kernel checks for a capability, it checks pE. The other capability masks serve to modify what capabilities can be in pE. Any task can remove capabilities from pE, pP, or pI at any time. If a task has a capability in pP, it can add that capability to pE and/or pI. If a task has CAP_SETPCAP, then it can add any capability to pI, and it can remove capabilities from X. Tasks are not the only things that can have capabilities; files can also have capabilities. A file can have no capabilty information at all [1]. If a file has capability information, then it has a permitted mask (fP) and an inheritable mask (fI) as well as a single effective bit (fE) [2]. File capabilities modify the capabilities of tasks that execve(2) them. A task that successfully calls execve has its capabilities modified for the file ultimately being excecuted (i.e. the binary itself if that binary is ELF or for the interpreter if the binary is a script.) [3] In the capability evolution rules, for each mask Z, pZ represents the old value and pZ' represents the new value. The rules are: pP' = (X & fP) | (pI & fI) pI' = pI pE' = (fE ? pP' : 0) X is unchanged For setuid binaries, fP, fI, and fE are modified by a moderately complicated set of rules that emulate POSIX behavior. Similarly, if euid == 0 or ruid == 0, then fP, fI, and fE are modified differently (primary, fP and fI usually end up being the full set). For nonroot users executing binaries with neither setuid nor file caps, fI and fP are empty and fE is false. As an extra complication, if you execute a process as nonroot and fE is set, then the "secure exec" rules are in effect: AT_SECURE gets set, LD_PRELOAD doesn't work, etc. This is rather messy. We've learned that making any changes is dangerous, though: if a new kernel version allows an unprivileged program to change its security state in a way that persists cross execution of a setuid program or a program with file caps, this persistent state is surprisingly likely to allow setuid or file-capped programs to be exploited for privilege escalation. ===== The problem ===== Capability inheritance is basically useless. If you aren't root and you execute an ordinary binary, fI is zero, so your capabilities have no effect whatsoever on pP'. This means that you can't usefully execute a helper process or a shell command with elevated capabilities if you aren't root. On current kernels, you can sort of work around this by setting fI to the full set for most or all non-setuid executable files. This causes pP' = pI for nonroot, and inheritance works. No one does this because it's a PITA and it isn't even supported on most filesystems. If you try this, you'll discover that every nonroot program ends up with secure exec rules, breaking many things. This is a problem that has bitten many people who have tried to use capabilities for anything useful. ===== The proposed change ===== This patch adds a fifth capability mask called the ambient mask (pA). pA does what most people expect pI to do. pA obeys the invariant that no bit can ever be set in pA if it is not set in both pP and pI. Dropping a bit from pP or pI drops that bit from pA. This ensures that existing programs that try to drop capabilities still do so, with a complication. Because capability inheritance is so broken, setting KEEPCAPS, using setresuid to switch to nonroot uids, and then calling execve effectively drops capabilities. Therefore, setresuid from root to nonroot conditionally clears pA unless SECBIT_NO_SETUID_FIXUP is set. Processes that don't like this can re-add bits to pA afterwards. The capability evolution rules are changed: pA' = (file caps or setuid or setgid ? 0 : pA) pP' = (X & fP) | (pI & fI) | pA' pI' = pI pE' = (fE ? pP' : pA') X is unchanged If you are nonroot but you have a capability, you can add it to pA. If you do so, your children get that capability in pA, pP, and pE. For example, you can set pA = CAP_NET_BIND_SERVICE, and your children can automatically bind low-numbered ports. Hallelujah! Unprivileged users can create user namespaces, map themselves to a nonzero uid, and create both privileged (relative to their namespace) and unprivileged process trees. This is currently more or less impossible. Hallelujah! You cannot use pA to try to subvert a setuid, setgid, or file-capped program: if you execute any such program, pA gets cleared and the resulting evolution rules are unchanged by this patch. Users with nonzero pA are unlikely to unintentionally leak that capability. If they run programs that try to drop privileges, dropping privileges will still work. It's worth noting that the degree of paranoia in this patch could possibly be reduced without causing serious problems. Specifically, if we allowed pA to persist across executing non-pA-aware setuid binaries and across setresuid, then, naively, the only capabilities that could leak as a result would be the capabilities in pA, and any attacker *already* has those capabilities. This would make me nervous, though -- setuid binaries that tried to privilege-separate might fail to do so, and putting CAP_DAC_READ_SEARCH or CAP_DAC_OVERRIDE into pA could have unexpected side effects. (Whether these unexpected side effects would be exploitable is an open question.) I've therefore taken the more paranoid route. We can revisit this later. An alternative would be to require PR_SET_NO_NEW_PRIVS before setting ambient capabilities. I think that this would be annoying and would make granting otherwise unprivileged users minor ambient capabilities (CAP_NET_BIND_SERVICE or CAP_NET_RAW for example) much less useful than it is with this patch. ===== Footnotes ===== [1] Files that are missing the "security.capability" xattr or that have unrecognized values for that xattr end up with has_cap set to false. The code that does that appears to be complicated for no good reason. [2] The libcap capability mask parsers and formatters are dangerously misleading and the documentation is flat-out wrong. fE is *not* a mask; it's a single bit. This has probably confused every single person who has tried to use file capabilities. [3] Linux very confusingly processes both the script and the interpreter if applicable, for reasons that elude me. The results from thinking about a script's file capabilities and/or setuid bits are mostly discarded. Preliminary userspace code is here, but it needs updating: https://git.kernel.org/cgit/linux/kernel/git/luto/util-linux-playground.git/commit/?h=cap_ambient&id=7f5afbd175d2 Here is a test program that can be used to verify the functionality (from Christoph): /* * Test program for the ambient capabilities. This program spawns a shell * that allows running processes with a defined set of capabilities. * * (C) 2015 Christoph Lameter <cl@linux.com> * Released under: GPL v3 or later. * * * Compile using: * * gcc -o ambient_test ambient_test.o -lcap-ng * * This program must have the following capabilities to run properly: * Permissions for CAP_NET_RAW, CAP_NET_ADMIN, CAP_SYS_NICE * * A command to equip the binary with the right caps is: * * setcap cap_net_raw,cap_net_admin,cap_sys_nice+p ambient_test * * * To get a shell with additional caps that can be inherited by other processes: * * ./ambient_test /bin/bash * * * Verifying that it works: * * From the bash spawed by ambient_test run * * cat /proc/$$/status * * and have a look at the capabilities. */ #include <stdlib.h> #include <stdio.h> #include <errno.h> #include <cap-ng.h> #include <sys/prctl.h> #include <linux/capability.h> /* * Definitions from the kernel header files. These are going to be removed * when the /usr/include files have these defined. */ #define PR_CAP_AMBIENT 47 #define PR_CAP_AMBIENT_IS_SET 1 #define PR_CAP_AMBIENT_RAISE 2 #define PR_CAP_AMBIENT_LOWER 3 #define PR_CAP_AMBIENT_CLEAR_ALL 4 static void set_ambient_cap(int cap) { int rc; capng_get_caps_process(); rc = capng_update(CAPNG_ADD, CAPNG_INHERITABLE, cap); if (rc) { printf("Cannot add inheritable cap\n"); exit(2); } capng_apply(CAPNG_SELECT_CAPS); /* Note the two 0s at the end. Kernel checks for these */ if (prctl(PR_CAP_AMBIENT, PR_CAP_AMBIENT_RAISE, cap, 0, 0)) { perror("Cannot set cap"); exit(1); } } int main(int argc, char **argv) { int rc; set_ambient_cap(CAP_NET_RAW); set_ambient_cap(CAP_NET_ADMIN); set_ambient_cap(CAP_SYS_NICE); printf("Ambient_test forking shell\n"); if (execv(argv[1], argv + 1)) perror("Cannot exec"); return 0; } Signed-off-by: Christoph Lameter <cl@linux.com> # Original author Signed-off-by: Andy Lutomirski <luto@kernel.org> Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Aaron Jones <aaronmdjones@gmail.com> Cc: Ted Ts'o <tytso@mit.edu> Cc: Andrew G. Morgan <morgan@kernel.org> Cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Austin S Hemmelgarn <ahferroin7@gmail.com> Cc: Markku Savela <msa@moth.iki.fi> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: James Morris <james.l.morris@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
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Paul Burton
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9791554b45 |
MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS
Userland code may be built using an ABI which permits linking to objects that have more restrictive floating point requirements. For example, userland code may be built to target the O32 FPXX ABI. Such code may be linked with other FPXX code, or code built for either one of the more restrictive FP32 or FP64. When linking with more restrictive code, the overall requirement of the process becomes that of the more restrictive code. The kernel has no way to know in advance which mode the process will need to be executed in, and indeed it may need to change during execution. The dynamic loader is the only code which will know the overall required mode, and so it needs to have a means to instruct the kernel to switch the FP mode of the process. This patch introduces 2 new options to the prctl syscall which provide such a capability. The FP mode of the process is represented as a simple bitmask combining a number of mode bits mirroring those present in the hardware. Userland can either retrieve the current FP mode of the process: mode = prctl(PR_GET_FP_MODE); or modify the current FP mode of the process: err = prctl(PR_SET_FP_MODE, new_mode); Signed-off-by: Paul Burton <paul.burton@imgtec.com> Cc: Matthew Fortune <matthew.fortune@imgtec.com> Cc: Markos Chandras <markos.chandras@imgtec.com> Cc: linux-mips@linux-mips.org Patchwork: https://patchwork.linux-mips.org/patch/8899/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> |
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Dave Hansen
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fe3d197f84 |
x86, mpx: On-demand kernel allocation of bounds tables
This is really the meat of the MPX patch set. If there is one patch to review in the entire series, this is the one. There is a new ABI here and this kernel code also interacts with userspace memory in a relatively unusual manner. (small FAQ below). Long Description: This patch adds two prctl() commands to provide enable or disable the management of bounds tables in kernel, including on-demand kernel allocation (See the patch "on-demand kernel allocation of bounds tables") and cleanup (See the patch "cleanup unused bound tables"). Applications do not strictly need the kernel to manage bounds tables and we expect some applications to use MPX without taking advantage of this kernel support. This means the kernel can not simply infer whether an application needs bounds table management from the MPX registers. The prctl() is an explicit signal from userspace. PR_MPX_ENABLE_MANAGEMENT is meant to be a signal from userspace to require kernel's help in managing bounds tables. PR_MPX_DISABLE_MANAGEMENT is the opposite, meaning that userspace don't want kernel's help any more. With PR_MPX_DISABLE_MANAGEMENT, the kernel won't allocate and free bounds tables even if the CPU supports MPX. PR_MPX_ENABLE_MANAGEMENT will fetch the base address of the bounds directory out of a userspace register (bndcfgu) and then cache it into a new field (->bd_addr) in the 'mm_struct'. PR_MPX_DISABLE_MANAGEMENT will set "bd_addr" to an invalid address. Using this scheme, we can use "bd_addr" to determine whether the management of bounds tables in kernel is enabled. Also, the only way to access that bndcfgu register is via an xsaves, which can be expensive. Caching "bd_addr" like this also helps reduce the cost of those xsaves when doing table cleanup at munmap() time. Unfortunately, we can not apply this optimization to #BR fault time because we need an xsave to get the value of BNDSTATUS. ==== Why does the hardware even have these Bounds Tables? ==== MPX only has 4 hardware registers for storing bounds information. If MPX-enabled code needs more than these 4 registers, it needs to spill them somewhere. It has two special instructions for this which allow the bounds to be moved between the bounds registers and some new "bounds tables". They are similar conceptually to a page fault and will be raised by the MPX hardware during both bounds violations or when the tables are not present. This patch handles those #BR exceptions for not-present tables by carving the space out of the normal processes address space (essentially calling the new mmap() interface indroduced earlier in this patch set.) and then pointing the bounds-directory over to it. The tables *need* to be accessed and controlled by userspace because the instructions for moving bounds in and out of them are extremely frequent. They potentially happen every time a register pointing to memory is dereferenced. Any direct kernel involvement (like a syscall) to access the tables would obviously destroy performance. ==== Why not do this in userspace? ==== This patch is obviously doing this allocation in the kernel. However, MPX does not strictly *require* anything in the kernel. It can theoretically be done completely from userspace. Here are a few ways this *could* be done. I don't think any of them are practical in the real-world, but here they are. Q: Can virtual space simply be reserved for the bounds tables so that we never have to allocate them? A: As noted earlier, these tables are *HUGE*. An X-GB virtual area needs 4*X GB of virtual space, plus 2GB for the bounds directory. If we were to preallocate them for the 128TB of user virtual address space, we would need to reserve 512TB+2GB, which is larger than the entire virtual address space today. This means they can not be reserved ahead of time. Also, a single process's pre-popualated bounds directory consumes 2GB of virtual *AND* physical memory. IOW, it's completely infeasible to prepopulate bounds directories. Q: Can we preallocate bounds table space at the same time memory is allocated which might contain pointers that might eventually need bounds tables? A: This would work if we could hook the site of each and every memory allocation syscall. This can be done for small, constrained applications. But, it isn't practical at a larger scale since a given app has no way of controlling how all the parts of the app might allocate memory (think libraries). The kernel is really the only place to intercept these calls. Q: Could a bounds fault be handed to userspace and the tables allocated there in a signal handler instead of in the kernel? A: (thanks to tglx) mmap() is not on the list of safe async handler functions and even if mmap() would work it still requires locking or nasty tricks to keep track of the allocation state there. Having ruled out all of the userspace-only approaches for managing bounds tables that we could think of, we create them on demand in the kernel. Based-on-patch-by: Qiaowei Ren <qiaowei.ren@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-mips@linux-mips.org Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20141114151829.AD4310DE@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> |
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Cyrill Gorcunov
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f606b77f1a |
prctl: PR_SET_MM -- introduce PR_SET_MM_MAP operation
During development of c/r we've noticed that in case if we need to support
user namespaces we face a problem with capabilities in prctl(PR_SET_MM,
...) call, in particular once new user namespace is created
capable(CAP_SYS_RESOURCE) no longer passes.
A approach is to eliminate CAP_SYS_RESOURCE check but pass all new values
in one bundle, which would allow the kernel to make more intensive test
for sanity of values and same time allow us to support checkpoint/restore
of user namespaces.
Thus a new command PR_SET_MM_MAP introduced. It takes a pointer of
prctl_mm_map structure which carries all the members to be updated.
prctl(PR_SET_MM, PR_SET_MM_MAP, struct prctl_mm_map *, size)
struct prctl_mm_map {
__u64 start_code;
__u64 end_code;
__u64 start_data;
__u64 end_data;
__u64 start_brk;
__u64 brk;
__u64 start_stack;
__u64 arg_start;
__u64 arg_end;
__u64 env_start;
__u64 env_end;
__u64 *auxv;
__u32 auxv_size;
__u32 exe_fd;
};
All members except @exe_fd correspond ones of struct mm_struct. To figure
out which available values these members may take here are meanings of the
members.
- start_code, end_code: represent bounds of executable code area
- start_data, end_data: represent bounds of data area
- start_brk, brk: used to calculate bounds for brk() syscall
- start_stack: used when accounting space needed for command
line arguments, environment and shmat() syscall
- arg_start, arg_end, env_start, env_end: represent memory area
supplied for command line arguments and environment variables
- auxv, auxv_size: carries auxiliary vector, Elf format specifics
- exe_fd: file descriptor number for executable link (/proc/self/exe)
Thus we apply the following requirements to the values
1) Any member except @auxv, @auxv_size, @exe_fd is rather an address
in user space thus it must be laying inside [mmap_min_addr, mmap_max_addr)
interval.
2) While @[start|end]_code and @[start|end]_data may point to an nonexisting
VMAs (say a program maps own new .text and .data segments during execution)
the rest of members should belong to VMA which must exist.
3) Addresses must be ordered, ie @start_ member must not be greater or
equal to appropriate @end_ member.
4) As in regular Elf loading procedure we require that @start_brk and
@brk be greater than @end_data.
5) If RLIMIT_DATA rlimit is set to non-infinity new values should not
exceed existing limit. Same applies to RLIMIT_STACK.
6) Auxiliary vector size must not exceed existing one (which is
predefined as AT_VECTOR_SIZE and depends on architecture).
7) File descriptor passed in @exe_file should be pointing
to executable file (because we use existing prctl_set_mm_exe_file_locked
helper it ensures that the file we are going to use as exe link has all
required permission granted).
Now about where these members are involved inside kernel code:
- @start_code and @end_code are used in /proc/$pid/[stat|statm] output;
- @start_data and @end_data are used in /proc/$pid/[stat|statm] output,
also they are considered if there enough space for brk() syscall
result if RLIMIT_DATA is set;
- @start_brk shown in /proc/$pid/stat output and accounted in brk()
syscall if RLIMIT_DATA is set; also this member is tested to
find a symbolic name of mmap event for perf system (we choose
if event is generated for "heap" area); one more aplication is
selinux -- we test if a process has PROCESS__EXECHEAP permission
if trying to make heap area being executable with mprotect() syscall;
- @brk is a current value for brk() syscall which lays inside heap
area, it's shown in /proc/$pid/stat. When syscall brk() succesfully
provides new memory area to a user space upon brk() completion the
mm::brk is updated to carry new value;
Both @start_brk and @brk are actively used in /proc/$pid/maps
and /proc/$pid/smaps output to find a symbolic name "heap" for
VMA being scanned;
- @start_stack is printed out in /proc/$pid/stat and used to
find a symbolic name "stack" for task and threads in
/proc/$pid/maps and /proc/$pid/smaps output, and as the same
as with @start_brk -- perf system uses it for event naming.
Also kernel treat this member as a start address of where
to map vDSO pages and to check if there is enough space
for shmat() syscall;
- @arg_start, @arg_end, @env_start and @env_end are printed out
in /proc/$pid/stat. Another access to the data these members
represent is to read /proc/$pid/environ or /proc/$pid/cmdline.
Any attempt to read these areas kernel tests with access_process_vm
helper so a user must have enough rights for this action;
- @auxv and @auxv_size may be read from /proc/$pid/auxv. Strictly
speaking kernel doesn't care much about which exactly data is
sitting there because it is solely for userspace;
- @exe_fd is referred from /proc/$pid/exe and when generating
coredump. We uses prctl_set_mm_exe_file_locked helper to update
this member, so exe-file link modification remains one-shot
action.
Still note that updating exe-file link now doesn't require sys-resource
capability anymore, after all there is no much profit in preventing setup
own file link (there are a number of ways to execute own code -- ptrace,
ld-preload, so that the only reliable way to find which exactly code is
executed is to inspect running program memory). Still we require the
caller to be at least user-namespace root user.
I believe the old interface should be deprecated and ripped off in a
couple of kernel releases if no one against.
To test if new interface is implemented in the kernel one can pass
PR_SET_MM_MAP_SIZE opcode and the kernel returns the size of currently
supported struct prctl_mm_map.
[akpm@linux-foundation.org: fix 80-col wordwrap in macro definitions]
Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: Andrew Vagin <avagin@openvz.org>
Tested-by: Andrew Vagin <avagin@openvz.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Julien Tinnes <jln@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Alex Thorlton
|
a0715cc226 |
mm, thp: add VM_INIT_DEF_MASK and PRCTL_THP_DISABLE
Add VM_INIT_DEF_MASK, to allow us to set the default flags for VMs. It also adds a prctl control which allows us to set the THP disable bit in mm->def_flags so that VMs will pick up the setting as they are created. Signed-off-by: Alex Thorlton <athorlton@sgi.com> Suggested-by: Oleg Nesterov <oleg@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Mel Gorman <mgorman@suse.de> Acked-by: Rik van Riel <riel@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: David Rientjes <rientjes@google.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> |
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David Howells
|
607ca46e97 |
UAPI: (Scripted) Disintegrate include/linux
Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Acked-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Dave Jones <davej@redhat.com> |