| Commit message (Collapse) | Author | Age |
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Changes in 4.4.180
kbuild: simplify ld-option implementation
KVM: fail KVM_SET_VCPU_EVENTS with invalid exception number
cifs: do not attempt cifs operation on smb2+ rename error
MIPS: scall64-o32: Fix indirect syscall number load
trace: Fix preempt_enable_no_resched() abuse
sched/numa: Fix a possible divide-by-zero
ceph: ensure d_name stability in ceph_dentry_hash()
ceph: fix ci->i_head_snapc leak
nfsd: Don't release the callback slot unless it was actually held
sunrpc: don't mark uninitialised items as VALID.
USB: Add new USB LPM helpers
USB: Consolidate LPM checks to avoid enabling LPM twice
powerpc/xmon: Add RFI flush related fields to paca dump
powerpc/64s: Improve RFI L1-D cache flush fallback
powerpc/pseries: Support firmware disable of RFI flush
powerpc/powernv: Support firmware disable of RFI flush
powerpc/rfi-flush: Move the logic to avoid a redo into the debugfs code
powerpc/rfi-flush: Make it possible to call setup_rfi_flush() again
powerpc/rfi-flush: Always enable fallback flush on pseries
powerpc/rfi-flush: Differentiate enabled and patched flush types
powerpc/pseries: Add new H_GET_CPU_CHARACTERISTICS flags
powerpc/rfi-flush: Call setup_rfi_flush() after LPM migration
powerpc: Add security feature flags for Spectre/Meltdown
powerpc/pseries: Set or clear security feature flags
powerpc/powernv: Set or clear security feature flags
powerpc/64s: Move cpu_show_meltdown()
powerpc/64s: Enhance the information in cpu_show_meltdown()
powerpc/powernv: Use the security flags in pnv_setup_rfi_flush()
powerpc/pseries: Use the security flags in pseries_setup_rfi_flush()
powerpc/64s: Wire up cpu_show_spectre_v1()
powerpc/64s: Wire up cpu_show_spectre_v2()
powerpc/pseries: Fix clearing of security feature flags
powerpc: Move default security feature flags
powerpc/pseries: Restore default security feature flags on setup
powerpc/64s: Fix section mismatch warnings from setup_rfi_flush()
powerpc/64s: Add support for a store forwarding barrier at kernel entry/exit
powerpc/64s: Add barrier_nospec
powerpc/64s: Add support for ori barrier_nospec patching
powerpc/64s: Patch barrier_nospec in modules
powerpc/64s: Enable barrier_nospec based on firmware settings
powerpc/64: Use barrier_nospec in syscall entry
powerpc: Use barrier_nospec in copy_from_user()
powerpc/64s: Enhance the information in cpu_show_spectre_v1()
powerpc64s: Show ori31 availability in spectre_v1 sysfs file not v2
powerpc/64: Disable the speculation barrier from the command line
powerpc/64: Make stf barrier PPC_BOOK3S_64 specific.
powerpc/64: Add CONFIG_PPC_BARRIER_NOSPEC
powerpc/64: Call setup_barrier_nospec() from setup_arch()
powerpc/64: Make meltdown reporting Book3S 64 specific
powerpc/fsl: Add barrier_nospec implementation for NXP PowerPC Book3E
powerpc/asm: Add a patch_site macro & helpers for patching instructions
powerpc/64s: Add new security feature flags for count cache flush
powerpc/64s: Add support for software count cache flush
powerpc/pseries: Query hypervisor for count cache flush settings
powerpc/powernv: Query firmware for count cache flush settings
powerpc: Avoid code patching freed init sections
powerpc/fsl: Add infrastructure to fixup branch predictor flush
powerpc/fsl: Add macro to flush the branch predictor
powerpc/fsl: Fix spectre_v2 mitigations reporting
powerpc/fsl: Add nospectre_v2 command line argument
powerpc/fsl: Flush the branch predictor at each kernel entry (64bit)
powerpc/fsl: Update Spectre v2 reporting
powerpc/security: Fix spectre_v2 reporting
powerpc/fsl: Fix the flush of branch predictor.
tipc: handle the err returned from cmd header function
slip: make slhc_free() silently accept an error pointer
intel_th: gth: Fix an off-by-one in output unassigning
fs/proc/proc_sysctl.c: Fix a NULL pointer dereference
NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
netfilter: ebtables: CONFIG_COMPAT: drop a bogus WARN_ON
tipc: check bearer name with right length in tipc_nl_compat_bearer_enable
tipc: check link name with right length in tipc_nl_compat_link_set
bpf: reject wrong sized filters earlier
Revert "block/loop: Use global lock for ioctl() operation."
ipv4: add sanity checks in ipv4_link_failure()
team: fix possible recursive locking when add slaves
net: stmmac: move stmmac_check_ether_addr() to driver probe
ipv4: set the tcp_min_rtt_wlen range from 0 to one day
powerpc/fsl: Enable runtime patching if nospectre_v2 boot arg is used
powerpc/fsl: Flush branch predictor when entering KVM
powerpc/fsl: Emulate SPRN_BUCSR register
powerpc/fsl: Flush the branch predictor at each kernel entry (32 bit)
powerpc/fsl: Sanitize the syscall table for NXP PowerPC 32 bit platforms
powerpc/fsl: Fixed warning: orphan section `__btb_flush_fixup'
powerpc/fsl: Add FSL_PPC_BOOK3E as supported arch for nospectre_v2 boot arg
Documentation: Add nospectre_v1 parameter
usbnet: ipheth: prevent TX queue timeouts when device not ready
usbnet: ipheth: fix potential null pointer dereference in ipheth_carrier_set
qlcnic: Avoid potential NULL pointer dereference
netfilter: bridge: set skb transport_header before entering NF_INET_PRE_ROUTING
sc16is7xx: missing unregister/delete driver on error in sc16is7xx_init()
usb: gadget: net2280: Fix overrun of OUT messages
usb: gadget: net2280: Fix net2280_dequeue()
usb: gadget: net2272: Fix net2272_dequeue()
ARM: dts: pfla02: increase phy reset duration
net: ks8851: Dequeue RX packets explicitly
net: ks8851: Reassert reset pin if chip ID check fails
net: ks8851: Delay requesting IRQ until opened
net: ks8851: Set initial carrier state to down
net: xilinx: fix possible object reference leak
net: ibm: fix possible object reference leak
net: ethernet: ti: fix possible object reference leak
scsi: qla4xxx: fix a potential NULL pointer dereference
usb: u132-hcd: fix resource leak
ceph: fix use-after-free on symlink traversal
scsi: zfcp: reduce flood of fcrscn1 trace records on multi-element RSCN
libata: fix using DMA buffers on stack
kconfig/[mn]conf: handle backspace (^H) key
vfio/type1: Limit DMA mappings per container
ALSA: line6: use dynamic buffers
ipv4: ip_do_fragment: Preserve skb_iif during fragmentation
ipv6/flowlabel: wait rcu grace period before put_pid()
ipv6: invert flowlabel sharing check in process and user mode
bnxt_en: Improve multicast address setup logic.
packet: validate msg_namelen in send directly
USB: yurex: Fix protection fault after device removal
USB: w1 ds2490: Fix bug caused by improper use of altsetting array
USB: core: Fix unterminated string returned by usb_string()
USB: core: Fix bug caused by duplicate interface PM usage counter
HID: debug: fix race condition with between rdesc_show() and device removal
rtc: sh: Fix invalid alarm warning for non-enabled alarm
igb: Fix WARN_ONCE on runtime suspend
bonding: show full hw address in sysfs for slave entries
jffs2: fix use-after-free on symlink traversal
debugfs: fix use-after-free on symlink traversal
rtc: da9063: set uie_unsupported when relevant
vfio/pci: use correct format characters
scsi: storvsc: Fix calculation of sub-channel count
net: hns: Use NAPI_POLL_WEIGHT for hns driver
net: hns: Fix WARNING when remove HNS driver with SMMU enabled
hugetlbfs: fix memory leak for resv_map
xsysace: Fix error handling in ace_setup
ARM: orion: don't use using 64-bit DMA masks
ARM: iop: don't use using 64-bit DMA masks
usb: usbip: fix isoc packet num validation in get_pipe
staging: iio: adt7316: allow adt751x to use internal vref for all dacs
staging: iio: adt7316: fix the dac read calculation
staging: iio: adt7316: fix the dac write calculation
Input: snvs_pwrkey - initialize necessary driver data before enabling IRQ
selinux: never allow relabeling on context mounts
x86/mce: Improve error message when kernel cannot recover, p2
media: v4l2: i2c: ov7670: Fix PLL bypass register values
scsi: libsas: fix a race condition when smp task timeout
ASoC:soc-pcm:fix a codec fixup issue in TDM case
ASoC: cs4270: Set auto-increment bit for register writes
ASoC: tlv320aic32x4: Fix Common Pins
perf/x86/intel: Fix handling of wakeup_events for multi-entry PEBS
scsi: csiostor: fix missing data copy in csio_scsi_err_handler()
iommu/amd: Set exclusion range correctly
genirq: Prevent use-after-free and work list corruption
usb: dwc3: Fix default lpm_nyet_threshold value
scsi: qla2xxx: Fix incorrect region-size setting in optrom SYSFS routines
Bluetooth: hidp: fix buffer overflow
Bluetooth: Align minimum encryption key size for LE and BR/EDR connections
UAS: fix alignment of scatter/gather segments
ipv6: fix a potential deadlock in do_ipv6_setsockopt()
ASoC: Intel: avoid Oops if DMA setup fails
timer/debug: Change /proc/timer_stats from 0644 to 0600
netfilter: compat: initialize all fields in xt_init
platform/x86: sony-laptop: Fix unintentional fall-through
iio: adc: xilinx: fix potential use-after-free on remove
HID: input: add mapping for Expose/Overview key
HID: input: add mapping for keyboard Brightness Up/Down/Toggle keys
libnvdimm/btt: Fix a kmemdup failure check
s390/dasd: Fix capacity calculation for large volumes
s390/3270: fix lockdep false positive on view->lock
KVM: x86: avoid misreporting level-triggered irqs as edge-triggered in tracing
tools lib traceevent: Fix missing equality check for strcmp
init: initialize jump labels before command line option parsing
ipvs: do not schedule icmp errors from tunnels
s390: ctcm: fix ctcm_new_device error return code
selftests/net: correct the return value for run_netsocktests
gpu: ipu-v3: dp: fix CSC handling
cw1200: fix missing unlock on error in cw1200_hw_scan()
x86/vdso: Pass --eh-frame-hdr to the linker
Don't jump to compute_result state from check_result state
locking/static_keys: Provide DECLARE and well as DEFINE macros
x86/microcode/intel: Add a helper which gives the microcode revision
x86: stop exporting msr-index.h to userland
bitops: avoid integer overflow in GENMASK(_ULL)
x86/microcode/intel: Check microcode revision before updating sibling threads
x86/MCE: Save microcode revision in machine check records
x86/cpufeatures: Hide AMD-specific speculation flags
x86/speculation: Support Enhanced IBRS on future CPUs
x86/speculation: Simplify the CPU bug detection logic
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
locking/atomics, asm-generic: Move some macros from <linux/bitops.h> to a new <linux/bits.h> file
x86/bugs: Fix the AMD SSBD usage of the SPEC_CTRL MSR
x86/speculation: Remove SPECTRE_V2_IBRS in enum spectre_v2_mitigation
x86/microcode: Make sure boot_cpu_data.microcode is up-to-date
x86/microcode: Update the new microcode revision unconditionally
x86/cpu: Sanitize FAM6_ATOM naming
KVM: x86: SVM: Call x86_spec_ctrl_set_guest/host() with interrupts disabled
x86/mm: Use WRITE_ONCE() when setting PTEs
x86/speculation: Apply IBPB more strictly to avoid cross-process data leak
x86/speculation: Enable cross-hyperthread spectre v2 STIBP mitigation
x86/speculation: Propagate information about RSB filling mitigation to sysfs
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
x86/Kconfig: Select SCHED_SMT if SMP enabled
sched: Add sched_smt_active()
x86/speculation: Rework SMT state change
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()
x86/speculation: Split out TIF update
x86/speculation: Prepare arch_smt_update() for PRCTL mode
x86/speculation: Prevent stale SPEC_CTRL msr content
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: x86: Report STIBP on GET_SUPPORTED_CPUID
x86/msr-index: Cleanup bit defines
x86/speculation: Consolidate CPU whitelists
x86/speculation/mds: Add basic bug infrastructure for MDS
x86/speculation/mds: Add BUG_MSBDS_ONLY
x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests
x86/speculation/mds: Add mds_clear_cpu_buffers()
x86/speculation/mds: Clear CPU buffers on exit to user
x86/speculation/mds: Conditionally clear CPU buffers on idle entry
x86/speculation/mds: Add mitigation control for MDS
x86/speculation/l1tf: Document l1tf in sysfs
x86/speculation/mds: Add sysfs reporting for MDS
x86/speculation/mds: Add mitigation mode VMWERV
Documentation: Move L1TF to separate directory
Documentation: Add MDS vulnerability documentation
x86/cpu/bugs: Use __initconst for 'const' init data
x86/speculation: Move arch_smt_update() call to after mitigation decisions
x86/speculation/mds: Add SMT warning message
x86/speculation/mds: Fix comment
x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off
cpu/speculation: Add 'mitigations=' cmdline option
x86/speculation: Support 'mitigations=' cmdline option
x86/speculation/mds: Add 'mitigations=' support for MDS
x86/mds: Add MDSUM variant to the MDS documentation
Documentation: Correct the possible MDS sysfs values
x86/speculation/mds: Fix documentation typo
x86/bugs: Change L1TF mitigation string to match upstream
USB: serial: use variable for status
USB: serial: fix unthrottle races
powerpc/64s: Include cpu header
bridge: Fix error path for kobject_init_and_add()
net: ucc_geth - fix Oops when changing number of buffers in the ring
packet: Fix error path in packet_init
vlan: disable SIOCSHWTSTAMP in container
vrf: sit mtu should not be updated when vrf netdev is the link
ipv4: Fix raw socket lookup for local traffic
bonding: fix arp_validate toggling in active-backup mode
drivers/virt/fsl_hypervisor.c: dereferencing error pointers in ioctl
drivers/virt/fsl_hypervisor.c: prevent integer overflow in ioctl
powerpc/booke64: set RI in default MSR
powerpc/lib: fix book3s/32 boot failure due to code patching
Linux 4.4.180
Change-Id: If2d2fdd451b55c002666b32022b269cec9545607
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
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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>
Link: https://lkml.kernel.org/r/20181125185005.866780996@linutronix.de
[bwh: Backported to 4.4:
- Renumber the PFA flags
- Drop changes in tools/include/uapi/linux/prctl.h
- Adjust filename]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Changes in 4.4.144
KVM/Eventfd: Avoid crash when assign and deassign specific eventfd in parallel.
x86/MCE: Remove min interval polling limitation
fat: fix memory allocation failure handling of match_strdup()
ALSA: rawmidi: Change resized buffers atomically
ARC: Fix CONFIG_SWAP
ARC: mm: allow mprotect to make stack mappings executable
mm: memcg: fix use after free in mem_cgroup_iter()
ipv4: Return EINVAL when ping_group_range sysctl doesn't map to user ns
ipv6: fix useless rol32 call on hash
lib/rhashtable: consider param->min_size when setting initial table size
net/ipv4: Set oif in fib_compute_spec_dst
net: phy: fix flag masking in __set_phy_supported
ptp: fix missing break in switch
tg3: Add higher cpu clock for 5762.
net: Don't copy pfmemalloc flag in __copy_skb_header()
skbuff: Unconditionally copy pfmemalloc in __skb_clone()
xhci: Fix perceived dead host due to runtime suspend race with event handler
x86/paravirt: Make native_save_fl() extern inline
x86/cpufeatures: Add CPUID_7_EDX CPUID leaf
x86/cpufeatures: Add Intel feature bits for Speculation Control
x86/cpufeatures: Add AMD feature bits for Speculation Control
x86/msr: Add definitions for new speculation control MSRs
x86/pti: Do not enable PTI on CPUs which are not vulnerable to Meltdown
x86/cpufeature: Blacklist SPEC_CTRL/PRED_CMD on early Spectre v2 microcodes
x86/speculation: Add basic IBPB (Indirect Branch Prediction Barrier) support
x86/cpufeatures: Clean up Spectre v2 related CPUID flags
x86/cpuid: Fix up "virtual" IBRS/IBPB/STIBP feature bits on Intel
x86/pti: Mark constant arrays as __initconst
x86/asm/entry/32: Simplify pushes of zeroed pt_regs->REGs
x86/entry/64/compat: Clear registers for compat syscalls, to reduce speculation attack surface
x86/speculation: Update Speculation Control microcode blacklist
x86/speculation: Correct Speculation Control microcode blacklist again
x86/speculation: Clean up various Spectre related details
x86/speculation: Fix up array_index_nospec_mask() asm constraint
x86/speculation: Add <asm/msr-index.h> dependency
x86/xen: Zero MSR_IA32_SPEC_CTRL before suspend
x86/mm: Factor out LDT init from context init
x86/mm: Give each mm TLB flush generation a unique ID
x86/speculation: Use Indirect Branch Prediction Barrier in context switch
x86/spectre_v2: Don't check microcode versions when running under hypervisors
x86/speculation: Use IBRS if available before calling into firmware
x86/speculation: Move firmware_restrict_branch_speculation_*() from C to CPP
x86/speculation: Remove Skylake C2 from Speculation Control microcode blacklist
selftest/seccomp: Fix the flag name SECCOMP_FILTER_FLAG_TSYNC
selftest/seccomp: Fix the seccomp(2) signature
xen: set cpu capabilities from xen_start_kernel()
x86/amd: don't set X86_BUG_SYSRET_SS_ATTRS when running under Xen
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/cpu: Rename Merrifield2 to Moorefield
x86/cpu/intel: Add Knights Mill to Intel family
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/speculation: Create spec-ctrl.h to avoid include hell
prctl: Add speculation control prctls
x86/process: Optimize TIF checks in __switch_to_xtra()
x86/process: Correct and optimize TIF_BLOCKSTEP switch
x86/process: Optimize TIF_NOTSC switch
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
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
x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP
x86/cpufeatures: Disentangle MSR_SPEC_CTRL enumeration from IBRS
x86/cpufeatures: Disentangle SSBD enumeration
x86/cpu/AMD: Fix erratum 1076 (CPB bit)
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
x86/bugs: Rename SSBD_NO to SSB_NO
x86/xen: Add call of speculative_store_bypass_ht_init() to PV paths
x86/cpu: Re-apply forced caps every time CPU caps are re-read
block: do not use interruptible wait anywhere
clk: tegra: Fix PLL_U post divider and initial rate on Tegra30
ubi: Introduce vol_ignored()
ubi: Rework Fastmap attach base code
ubi: Be more paranoid while seaching for the most recent Fastmap
ubi: Fix races around ubi_refill_pools()
ubi: Fix Fastmap's update_vol()
ubi: fastmap: Erase outdated anchor PEBs during attach
Linux 4.4.144
Change-Id: Ia3e9b2b7bc653cba68b76878d34f8fcbbc007a13
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
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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: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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: David Woodhouse <dwmw@amazon.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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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>
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PR_SET_TIMERSLACK_PID value keep colliding with that of
newer prctls in mainline (e.g. first with PR_SET_THP_DISABLE,
and again with PR_MPX_ENABLE_MANAGEMENT).
So reset PR_SET_TIMERSLACK_PID to a large number so as to
avoid conflict in the near term while it is out of mainline
tree.
Corresponding Change-Id up for review in platform/system/core
is Icd8c658c8eb62136dc26c2c4c94f7782e9827cdb
Change-Id: I061b25473acc020c13ee22ecfb32336bc358e76a
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>
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thread.
Second argument is similar to PR_SET_TIMERSLACK, if non-zero then the
slack is set to that value otherwise sets it to the default for the thread.
Takes PID of the thread as the third argument.
This allows power/performance management software to set timer slack for
other threads according to its policy for the thread (such as when the
thread is designated foreground vs. background activity)
Change-Id: I744d451ff4e60dae69f38f53948ff36c51c14a3f
Signed-off-by: Ruchi Kandoi <kandoiruchi@google.com>
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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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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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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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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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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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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>
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