5ab8271...
by
Linus Torvalds <email address hidden>
fs/proc: simplify and clarify get_mm_cmdline() function
We have some very odd semantics for reading the command line through
/proc, because we allow people to rewrite their own command line pretty
much at will, and things get positively funky when you extend your
command line past the point that used to be the end of the command line,
and is now in the environment variable area.
But our weird semantics doesn't mean that we should write weird and
complex code to handle them.
So re-write get_mm_cmdline() to be much simpler, and much more explicit
about what it is actually doing and why. And avoid the extra check for
"is there a NUL character at the end of the command line where I expect
one to be", by simply making the NUL character handling be part of the
normal "once you hit the end of the command line, stop at the first NUL
character" logic.
It's quite possible that we should stop the crazy "walk into
environment" entirely, but happily it's not really the usual case.
NOTE! We tried to really simplify and limit our odd cmdline parsing some
time ago, but people complained. See commit c2c0bb44620d ("proc: fix
PAGE_SIZE limit of /proc/$PID/cmdline") for details about why we have
this complexity.
e4b4e44...
by
Linus Torvalds <email address hidden>
fs/proc: re-factor proc_pid_cmdline_read() a bit
This is a pure refactoring of the function, preparing for some further
cleanups. The thing was pretty illegible, and the core functionality
still is, but now the core loop is a bit more isolated from the thing
that goes on around it.
This was "inspired" by the confluence of kworker workqueue name cleanups
by Tejun, currently scheduled for 4.18, and commit 7f7ccc2ccc2e ("proc:
do not access cmdline nor environ from file-backed areas").
58ddfe6...
by
Linus Torvalds <email address hidden>
Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm
Pull kvm fixes from Paolo Bonzini:
- ARM/ARM64 locking fixes
- x86 fixes: PCID, UMIP, locking
- improved support for recent Windows version that have a 2048 Hz APIC
timer
- rename KVM_HINTS_DEDICATED CPUID bit to KVM_HINTS_REALTIME
- better behaved selftests
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME
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
KVM: arm/arm64: VGIC/ITS: Promote irq_lock() in update_affinity
KVM: arm/arm64: Properly protect VGIC locks from IRQs
KVM: X86: Lower the default timer frequency limit to 200us
KVM: vmx: update sec exec controls for UMIP iff emulating UMIP
kvm: x86: Suppress CR3_PCID_INVD bit only when PCIDs are enabled
KVM: selftests: exit with 0 status code when tests cannot be run
KVM: hyperv: idr_find needs RCU protection
x86: Delay skip of emulated hypercall instruction
KVM: Extend MAX_IRQ_ROUTES to 4096 for all archs
7c9a0fc...
by
Linus Torvalds <email address hidden>
Merge tag 'sound-4.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound
Pull sound fixes from Takashi Iwai:
"We have a core fix in the compat code for covering a potential race
(double references), but it's a very minor change.
The rest are all small device-specific quirks, as well as a correction
of the new UAC3 support code"
* tag 'sound-4.17-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
ALSA: usb-audio: Use Class Specific EP for UAC3 devices.
ALSA: hda/realtek - Clevo P950ER ALC1220 Fixup
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
kvm: rename KVM_HINTS_DEDICATED to KVM_HINTS_REALTIME
KVM_HINTS_DEDICATED seems to be somewhat confusing:
Guest doesn't really care whether it's the only task running on a host
CPU as long as it's not preempted.
And there are more reasons for Guest to be preempted than host CPU
sharing, for example, with memory overcommit it can get preempted on a
memory access, post copy migration can cause preemption, etc.
Let's call it KVM_HINTS_REALTIME which seems to better
match what guests expect.
Also, the flag most be set on all vCPUs - current guests assume this.
Note so in the documentation.
Signed-off-by: Michael S. Tsirkin <email address hidden>
Signed-off-by: Paolo Bonzini <email address hidden>
3e9245c...
by
Linus Torvalds <email address hidden>
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 fixes from Martin Schwidefsky:
- a fix for the vfio ccw translation code
- update an incorrect email address in the MAINTAINERS file
- fix a division by zero oops in the cpum_sf code found by trinity
- two fixes for the error handling of the qdio code
- several spectre related patches to convert all left-over indirect
branches in the kernel to expoline branches
- update defconfigs to avoid warnings due to the netfilter Kconfig
changes
- avoid several compiler warnings in the kexec_file code for s390
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
s390/qdio: don't release memory in qdio_setup_irq()
s390/qdio: fix access to uninitialized qdio_q fields
s390/cpum_sf: ensure sample frequency of perf event attributes is non-zero
s390: use expoline thunks in the BPF JIT
s390: extend expoline to BC instructions
s390: remove indirect branch from do_softirq_own_stack
s390: move spectre sysfs attribute code
s390/kernel: use expoline for indirect branches
s390/ftrace: use expoline for indirect branches
s390/lib: use expoline for indirect branches
s390/crc32-vx: use expoline for indirect branches
s390: move expoline assembler macros to a header
vfio: ccw: fix cleanup if cp_prefetch fails
s390/kexec_file: add declaration of purgatory related globals
s390: update defconfigs
MAINTAINERS: update s390 zcrypt maintainers email address
305bb55...
by
Linus Torvalds <email address hidden>
Merge tag 'selinux-pr-20180516' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux
Pull SELinux fixes from Paul Moore:
"A small pull request to fix a few regressions in the SELinux/SCTP code
with applications that call bind() with AF_UNSPEC/INADDR_ANY.
The individual commit descriptions have more information, but the
commits themselves should be self explanatory"
* tag 'selinux-pr-20180516' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux:
selinux: correctly handle sa_family cases in selinux_sctp_bind_connect()
selinux: fix address family in bind() and connect() to match address/port
selinux: add AF_UNSPEC and INADDR_ANY checks to selinux_socket_bind()
proc: do not access cmdline nor environ from file-backed areas
proc_pid_cmdline_read() and environ_read() directly access the target
process' VM to retrieve the command line and environment. If this
process remaps these areas onto a file via mmap(), the requesting
process may experience various issues such as extra delays if the
underlying device is slow to respond.
Let's simply refuse to access file-backed areas in these functions.
For this we add a new FOLL_ANON gup flag that is passed to all calls
to access_remote_vm(). The code already takes care of such failures
(including unmapped areas). Accesses via /proc/pid/mem were not
changed though.
This was assigned CVE-2018-1120.
Note for stable backports: the patch may apply to kernels prior to 4.11
but silently miss one location; it must be checked that no call to
access_remote_vm() keeps zero as the last argument.
e6506eb...
by
Linus Torvalds <email address hidden>
Merge tag 'trace-v4.17-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull tracing fix from Steven Rostedt:
"Some of the ftrace internal events use a zero for a data size of a
field event. This is increasingly important for the histogram trigger
work that is being extended.
While auditing trace events, I found that a couple of the xen events
were used as just marking that a function was called, by creating a
static array of size zero. This can play havoc with the tracing
features if these events are used, because a zero size of a static
array is denoted as a special nul terminated dynamic array (this is
what the trace_marker code uses). But since the xen events have no
size, they are not nul terminated, and unexpected results may occur.
As trace events were never intended on being a marker to denote that a
function was hit or not, especially since function tracing and kprobes
can trivially do the same, the best course of action is to simply
remove these events"
* tag 'trace-v4.17-rc4-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
tracing/x86/xen: Remove zero data size trace events trace_xen_mmu_flush_tlb{_all}
9d38cd0...
by
Linus Torvalds <email address hidden>
Merge tag 'trace-v4.17-rc5-vsprintf' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace
Pull memory barrier for from Steven Rostedt:
"The memory barrier usage in updating the random ptr hash for %p in
vsprintf is incorrect.
Instead of adding the read memory barrier into vsprintf() which will
cause a slight degradation to a commonly used function in the kernel
just to solve a very unlikely race condition that can only happen at
boot up, change the code from using a variable branch to a
static_branch.
Not only does this solve the race condition, it actually will improve
the performance of vsprintf() by removing the conditional branch that
is only needed at boot"
* tag 'trace-v4.17-rc5-vsprintf' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
vsprintf: Replace memory barrier with static_key for random_ptr_key update
