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git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Catalin Marinas:
- Support for running Linux in a protected VM under the Arm
Confidential Compute Architecture (CCA)
- Guarded Control Stack user-space support. Current patches follow the
x86 ABI of implicitly creating a shadow stack on clone(). Subsequent
patches (already on the list) will add support for clone3() allowing
finer-grained control of the shadow stack size and placement from
libc
- AT_HWCAP3 support (not running out of HWCAP2 bits yet but we are
getting close with the upcoming dpISA support)
- Other arch features:
- In-kernel use of the memcpy instructions, FEAT_MOPS (previously
only exposed to user; uaccess support not merged yet)
- MTE: hugetlbfs support and the corresponding kselftests
- Optimise CRC32 using the PMULL instructions
- Support for FEAT_HAFT enabling ARCH_HAS_NONLEAF_PMD_YOUNG
- Optimise the kernel TLB flushing to use the range operations
- POE/pkey (permission overlays): further cleanups after bringing
the signal handler in line with the x86 behaviour for 6.12
- arm64 perf updates:
- Support for the NXP i.MX91 PMU in the existing IMX driver
- Support for Ampere SoCs in the Designware PCIe PMU driver
- Support for Marvell's 'PEM' PCIe PMU present in the 'Odyssey' SoC
- Support for Samsung's 'Mongoose' CPU PMU
- Support for PMUv3.9 finer-grained userspace counter access
control
- Switch back to platform_driver::remove() now that it returns
'void'
- Add some missing events for the CXL PMU driver
- Miscellaneous arm64 fixes/cleanups:
- Page table accessors cleanup: type updates, drop unused macros,
reorganise arch_make_huge_pte() and clean up pte_mkcont(), sanity
check addresses before runtime P4D/PUD folding
- Command line override for ID_AA64MMFR0_EL1.ECV (advertising the
FEAT_ECV for the generic timers) allowing Linux to boot with
firmware deployments that don't set SCTLR_EL3.ECVEn
- ACPI/arm64: tighten the check for the array of platform timer
structures and adjust the error handling procedure in
gtdt_parse_timer_block()
- Optimise the cache flush for the uprobes xol slot (skip if no
change) and other uprobes/kprobes cleanups
- Fix the context switching of tpidrro_el0 when kpti is enabled
- Dynamic shadow call stack fixes
- Sysreg updates
- Various arm64 kselftest improvements
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (168 commits)
arm64: tls: Fix context-switching of tpidrro_el0 when kpti is enabled
kselftest/arm64: Try harder to generate different keys during PAC tests
kselftest/arm64: Don't leak pipe fds in pac.exec_sign_all()
arm64/ptrace: Clarify documentation of VL configuration via ptrace
kselftest/arm64: Corrupt P0 in the irritator when testing SSVE
acpi/arm64: remove unnecessary cast
arm64/mm: Change protval as 'pteval_t' in map_range()
kselftest/arm64: Fix missing printf() argument in gcs/gcs-stress.c
kselftest/arm64: Add FPMR coverage to fp-ptrace
kselftest/arm64: Expand the set of ZA writes fp-ptrace does
kselftets/arm64: Use flag bits for features in fp-ptrace assembler code
kselftest/arm64: Enable build of PAC tests with LLVM=1
kselftest/arm64: Check that SVCR is 0 in signal handlers
selftests/mm: Fix unused function warning for aarch64_write_signal_pkey()
kselftest/arm64: Fix printf() compiler warnings in the arm64 syscall-abi.c tests
kselftest/arm64: Fix printf() warning in the arm64 MTE prctl() test
kselftest/arm64: Fix printf() compiler warnings in the arm64 fp tests
kselftest/arm64: Fix build with stricter assemblers
arm64/scs: Drop unused prototype __pi_scs_patch_vmlinux()
arm64/scs: Deal with 64-bit relative offsets in FDE frames
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fdget() is the first thing done in scope, all matching fdput() are
immediately followed by leaving the scope.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Three architectures (x86, aarch64, riscv) have announced support for
shadow stacks with fairly similar functionality. While x86 is using
arch_prctl() to control the functionality neither arm64 nor riscv uses
that interface so this patch adds arch-agnostic prctl() support to
get and set status of shadow stacks and lock the current configuation to
prevent further changes, with support for turning on and off individual
subfeatures so applications can limit their exposure to features that
they do not need. The features are:
- PR_SHADOW_STACK_ENABLE: Tracking and enforcement of shadow stacks,
including allocation of a shadow stack if one is not already
allocated.
- PR_SHADOW_STACK_WRITE: Writes to specific addresses in the shadow
stack.
- PR_SHADOW_STACK_PUSH: Push additional values onto the shadow stack.
These features are expected to be inherited by new threads and cleared
on exec(), unknown features should be rejected for enable but accepted
for locking (in order to allow for future proofing).
This is based on a patch originally written by Deepak Gupta but modified
fairly heavily, support for indirect landing pads is removed, additional
modes added and the locking interface reworked. The set status prctl()
is also reworked to just set flags, if setting/reading the shadow stack
pointer is required this could be a separate prctl.
Reviewed-by: Thiago Jung Bauermann <thiago.bauermann@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Yury Khrustalev <yury.khrustalev@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Deepak Gupta <debug@rivosinc.com>
Link: https://lore.kernel.org/r/20241001-arm64-gcs-v13-4-222b78d87eee@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull 'struct fd' updates from Al Viro:
"Just the 'struct fd' layout change, with conversion to accessor
helpers"
* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add struct fd constructors, get rid of __to_fd()
struct fd: representation change
introduce fd_file(), convert all accessors to it.
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Implement the SCHED_DEADLINE server infrastructure - Daniel Bristot
de Oliveira's last major contribution to the kernel:
"SCHED_DEADLINE servers can help fixing starvation issues of low
priority tasks (e.g., SCHED_OTHER) when higher priority tasks
monopolize CPU cycles. Today we have RT Throttling; DEADLINE
servers should be able to replace and improve that."
(Daniel Bristot de Oliveira, Peter Zijlstra, Joel Fernandes, Youssef
Esmat, Huang Shijie)
- Preparatory changes for sched_ext integration:
- Use set_next_task(.first) where required
- Fix up set_next_task() implementations
- Clean up DL server vs. core sched
- Split up put_prev_task_balance()
- Rework pick_next_task()
- Combine the last put_prev_task() and the first set_next_task()
- Rework dl_server
- Add put_prev_task(.next)
(Peter Zijlstra, with a fix by Tejun Heo)
- Complete the EEVDF transition and refine EEVDF scheduling:
- Implement delayed dequeue
- Allow shorter slices to wakeup-preempt
- Use sched_attr::sched_runtime to set request/slice suggestion
- Document the new feature flags
- Remove unused and duplicate-functionality fields
- Simplify & unify pick_next_task_fair()
- Misc debuggability enhancements
(Peter Zijlstra, with fixes/cleanups by Dietmar Eggemann, Valentin
Schneider and Chuyi Zhou)
- Initialize the vruntime of a new task when it is first enqueued,
resulting in significant decrease in latency of newly woken tasks
(Zhang Qiao)
- Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
(K Prateek Nayak, Peter Zijlstra)
- Clean up and clarify the usage of Clean up usage of rt_task()
(Qais Yousef)
- Preempt SCHED_IDLE entities in strict cgroup hierarchies
(Tianchen Ding)
- Clarify the documentation of time units for deadline scheduler
parameters (Christian Loehle)
- Remove the HZ_BW chicken-bit feature flag introduced a year ago,
the original change seems to be working fine (Phil Auld)
- Misc fixes and cleanups (Chen Yu, Dan Carpenter, Huang Shijie,
Peilin He, Qais Yousefm and Vincent Guittot)
* tag 'sched-core-2024-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
sched/cpufreq: Use NSEC_PER_MSEC for deadline task
cpufreq/cppc: Use NSEC_PER_MSEC for deadline task
sched/deadline: Clarify nanoseconds in uapi
sched/deadline: Convert schedtool example to chrt
sched/debug: Fix the runnable tasks output
sched: Fix sched_delayed vs sched_core
kernel/sched: Fix util_est accounting for DELAY_DEQUEUE
kthread: Fix task state in kthread worker if being frozen
sched/pelt: Use rq_clock_task() for hw_pressure
sched/fair: Move effective_cpu_util() and effective_cpu_util() in fair.c
sched/core: Introduce SM_IDLE and an idle re-entry fast-path in __schedule()
sched: Add put_prev_task(.next)
sched: Rework dl_server
sched: Combine the last put_prev_task() and the first set_next_task()
sched: Rework pick_next_task()
sched: Split up put_prev_task_balance()
sched: Clean up DL server vs core sched
sched: Fixup set_next_task() implementations
sched: Use set_next_task(.first) where required
sched/fair: Properly deactivate sched_delayed task upon class change
...
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The timerslack_ns setting is used to specify how much the hardware
timers should be delayed, to potentially dispatch multiple timers in a
single interrupt. This is a performance optimization. Timers of
realtime tasks (having a realtime scheduling policy) should not be
delayed.
This logic was inconsitently applied to the hrtimers, leading to delays
of realtime tasks which used timed waits for events (e.g. condition
variables). Due to the downstream override of the slack for rt tasks,
the procfs reported incorrect (non-zero) timerslack_ns values.
This is changed by setting the timer_slack_ns task attribute to 0 for
all tasks with a rt policy. By that, downstream users do not need to
specially handle rt tasks (w.r.t. the slack), and the procfs entry
shows the correct value of "0". Setting non-zero slack values (either
via procfs or PR_SET_TIMERSLACK) on tasks with a rt policy is ignored,
as stated in "man 2 PR_SET_TIMERSLACK":
Timer slack is not applied to threads that are scheduled under a
real-time scheduling policy (see sched_setscheduler(2)).
The special handling of timerslack on rt tasks in downstream users
is removed as well.
Signed-off-by: Felix Moessbauer <felix.moessbauer@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240814121032.368444-2-felix.moessbauer@siemens.com
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For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
This commit converts (almost) all of f.file to
fd_file(f). It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).
NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).
[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux
Pull RISC-V updates from Palmer Dabbelt:
- Add byte/half-word compare-and-exchange, emulated via LR/SC loops
- Support for Rust
- Support for Zihintpause in hwprobe
- Add PR_RISCV_SET_ICACHE_FLUSH_CTX prctl()
- Support lockless lockrefs
* tag 'riscv-for-linus-6.10-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
riscv: defconfig: Enable CONFIG_CLK_SOPHGO_CV1800
riscv: select ARCH_HAS_FAST_MULTIPLIER
riscv: mm: still create swiotlb buffer for kmalloc() bouncing if required
riscv: Annotate pgtable_l{4,5}_enabled with __ro_after_init
riscv: Remove redundant CONFIG_64BIT from pgtable_l{4,5}_enabled
riscv: mm: Always use an ASID to flush mm contexts
riscv: mm: Preserve global TLB entries when switching contexts
riscv: mm: Make asid_bits a local variable
riscv: mm: Use a fixed layout for the MM context ID
riscv: mm: Introduce cntx2asid/cntx2version helper macros
riscv: Avoid TLB flush loops when affected by SiFive CIP-1200
riscv: Apply SiFive CIP-1200 workaround to single-ASID sfence.vma
riscv: mm: Combine the SMP and UP TLB flush code
riscv: Only send remote fences when some other CPU is online
riscv: mm: Broadcast kernel TLB flushes only when needed
riscv: Use IPIs for remote cache/TLB flushes by default
riscv: Factor out page table TLB synchronization
riscv: Flush the instruction cache during SMP bringup
riscv: hwprobe: export Zihintpause ISA extension
riscv: misaligned: remove CONFIG_RISCV_M_MODE specific code
...
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Now that we track a DEXCR on a per-task basis, individual tasks are free
to configure it as they like.
The interface is a pair of getter/setter prctl's that work on a single
aspect at a time (multiple aspects at once is more difficult if there
are different rules applied for each aspect, now or in future). The
getter shows the current state of the process config, and the setter
allows setting/clearing the aspect.
Signed-off-by: Benjamin Gray <bgray@linux.ibm.com>
[mpe: Account for PR_RISCV_SET_ICACHE_FLUSH_CTX, shrink some longs lines]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240417112325.728010-5-bgray@linux.ibm.com
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prctl"
Charlie Jenkins <charlie@rivosinc.com> says:
Improve the performance of icache flushing by creating a new prctl flag
PR_RISCV_SET_ICACHE_FLUSH_CTX. The interface is left generic to allow
for future expansions such as with the proposed J extension [1].
Documentation is also provided to explain the use case.
Patch sent to add PR_RISCV_SET_ICACHE_FLUSH_CTX to man-pages [2].
[1] https://github.com/riscv/riscv-j-extension
[2] https://lore.kernel.org/linux-man/20240124-fencei_prctl-v1-1-0bddafcef331@rivosinc.com
* b4-shazam-merge:
cpumask: Add assign cpu
documentation: Document PR_RISCV_SET_ICACHE_FLUSH_CTX prctl
riscv: Include riscv_set_icache_flush_ctx prctl
riscv: Remove unnecessary irqflags processor.h include
Link: https://lore.kernel.org/r/20240312-fencei-v13-0-4b6bdc2bbf32@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Support new prctl with key PR_RISCV_SET_ICACHE_FLUSH_CTX to enable
optimization of cross modifying code. This prctl enables userspace code
to use icache flushing instructions such as fence.i with the guarantee
that the icache will continue to be clean after thread migration.
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Reviewed-by: Atish Patra <atishp@rivosinc.com>
Reviewed-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Reviewed-by: Samuel Holland <samuel.holland@sifive.com>
Link: https://lore.kernel.org/r/20240312-fencei-v13-2-4b6bdc2bbf32@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Patch series "ARM: prctl: Reject PR_SET_MDWE where not supported".
I noticed after a recent kernel update that my ARM926 system started
segfaulting on any execve() after calling prctl(PR_SET_MDWE). After some
investigation it appears that ARMv5 is incapable of providing the
appropriate protections for MDWE, since any readable memory is also
implicitly executable.
The prctl_set_mdwe() function already had some special-case logic added
disabling it on PARISC (commit 793838138c15, "prctl: Disable
prctl(PR_SET_MDWE) on parisc"); this patch series (1) generalizes that
check to use an arch_*() function, and (2) adds a corresponding override
for ARM to disable MDWE on pre-ARMv6 CPUs.
With the series applied, prctl(PR_SET_MDWE) is rejected on ARMv5 and
subsequent execve() calls (as well as mmap(PROT_READ|PROT_WRITE)) can
succeed instead of unconditionally failing; on ARMv6 the prctl works as it
did previously.
[0] https://lore.kernel.org/all/2023112456-linked-nape-bf19@gregkh/
This patch (of 2):
There exist systems other than PARISC where MDWE may not be feasible to
support; rather than cluttering up the generic code with additional
arch-specific logic let's add a generic function for checking MDWE support
and allow each arch to override it as needed.
Link: https://lkml.kernel.org/r/20240227013546.15769-4-zev@bewilderbeest.net
Link: https://lkml.kernel.org/r/20240227013546.15769-5-zev@bewilderbeest.net
Signed-off-by: Zev Weiss <zev@bewilderbeest.net>
Acked-by: Helge Deller <deller@gmx.de> [parisc]
Cc: Borislav Petkov <bp@alien8.de>
Cc: David Hildenbrand <david@redhat.com>
Cc: Florent Revest <revest@chromium.org>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Russell King (Oracle) <linux@armlinux.org.uk>
Cc: Sam James <sam@gentoo.org>
Cc: Stefan Roesch <shr@devkernel.io>
Cc: Yang Shi <yang@os.amperecomputing.com>
Cc: Yin Fengwei <fengwei.yin@intel.com>
Cc: <stable@vger.kernel.org> [6.3+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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lock_task_sighand() can trigger a hard lockup. If NR_CPUS threads call
getrusage() at the same time and the process has NR_THREADS, spin_lock_irq
will spin with irqs disabled O(NR_CPUS * NR_THREADS) time.
Change getrusage() to use sig->stats_lock, it was specifically designed
for this type of use. This way it runs lockless in the likely case.
TODO:
- Change do_task_stat() to use sig->stats_lock too, then we can
remove spin_lock_irq(siglock) in wait_task_zombie().
- Turn sig->stats_lock into seqcount_rwlock_t, this way the
readers in the slow mode won't exclude each other. See
https://lore.kernel.org/all/20230913154907.GA26210@redhat.com/
- stats_lock has to disable irqs because ->siglock can be taken
in irq context, it would be very nice to change __exit_signal()
to avoid the siglock->stats_lock dependency.
Link: https://lkml.kernel.org/r/20240122155053.GA26214@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dylan Hatch <dylanbhatch@google.com>
Tested-by: Dylan Hatch <dylanbhatch@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "getrusage: use sig->stats_lock", v2.
This patch (of 2):
thread_group_cputime() does its own locking, we can safely shift
thread_group_cputime_adjusted() which does another for_each_thread loop
outside of ->siglock protected section.
This is also preparation for the next patch which changes getrusage() to
use stats_lock instead of siglock, thread_group_cputime() takes the same
lock. With the current implementation recursive read_seqbegin_or_lock()
is fine, thread_group_cputime() can't enter the slow mode if the caller
holds stats_lock, yet this looks more safe and better performance-wise.
Link: https://lkml.kernel.org/r/20240122155023.GA26169@redhat.com
Link: https://lkml.kernel.org/r/20240122155050.GA26205@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reported-by: Dylan Hatch <dylanbhatch@google.com>
Tested-by: Dylan Hatch <dylanbhatch@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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systemd-254 tries to use prctl(PR_SET_MDWE) for it's MemoryDenyWriteExecute
functionality, but fails on parisc which still needs executable stacks in
certain combinations of gcc/glibc/kernel.
Disable prctl(PR_SET_MDWE) by returning -EINVAL for now on parisc, until
userspace has catched up.
Signed-off-by: Helge Deller <deller@gmx.de>
Co-developed-by: Linus Torvalds <torvalds@linux-foundation.org>
Reported-by: Sam James <sam@gentoo.org>
Closes: https://github.com/systemd/systemd/issues/29775
Tested-by: Sam James <sam@gentoo.org>
Link: https://lore.kernel.org/all/875y2jro9a.fsf@gentoo.org/
Cc: <stable@vger.kernel.org> # v6.3+
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"As usual, lots of singleton and doubleton patches all over the tree
and there's little I can say which isn't in the individual changelogs.
The lengthier patch series are
- 'kdump: use generic functions to simplify crashkernel reservation
in arch', from Baoquan He. This is mainly cleanups and
consolidation of the 'crashkernel=' kernel parameter handling
- After much discussion, David Laight's 'minmax: Relax type checks in
min() and max()' is here. Hopefully reduces some typecasting and
the use of min_t() and max_t()
- A group of patches from Oleg Nesterov which clean up and slightly
fix our handling of reads from /proc/PID/task/... and which remove
task_struct.thread_group"
* tag 'mm-nonmm-stable-2023-11-02-14-08' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (64 commits)
scripts/gdb/vmalloc: disable on no-MMU
scripts/gdb: fix usage of MOD_TEXT not defined when CONFIG_MODULES=n
.mailmap: add address mapping for Tomeu Vizoso
mailmap: update email address for Claudiu Beznea
tools/testing/selftests/mm/run_vmtests.sh: lower the ptrace permissions
.mailmap: map Benjamin Poirier's address
scripts/gdb: add lx_current support for riscv
ocfs2: fix a spelling typo in comment
proc: test ProtectionKey in proc-empty-vm test
proc: fix proc-empty-vm test with vsyscall
fs/proc/base.c: remove unneeded semicolon
do_io_accounting: use sig->stats_lock
do_io_accounting: use __for_each_thread()
ocfs2: replace BUG_ON() at ocfs2_num_free_extents() with ocfs2_error()
ocfs2: fix a typo in a comment
scripts/show_delta: add __main__ judgement before main code
treewide: mark stuff as __ro_after_init
fs: ocfs2: check status values
proc: test /proc/${pid}/statm
compiler.h: move __is_constexpr() to compiler.h
...
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This extends the current PR_SET_MDWE prctl arg with a bit to indicate that
the process doesn't want MDWE protection to propagate to children.
To implement this no-inherit mode, the tag in current->mm->flags must be
absent from MMF_INIT_MASK. This means that the encoding for "MDWE but
without inherit" is different in the prctl than in the mm flags. This
leads to a bit of bit-mangling in the prctl implementation.
Link: https://lkml.kernel.org/r/20230828150858.393570-6-revest@chromium.org
Signed-off-by: Florent Revest <revest@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexey Izbyshev <izbyshev@ispras.ru>
Cc: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: Ayush Jain <ayush.jain3@amd.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Greg Thelen <gthelen@google.com>
Cc: Joey Gouly <joey.gouly@arm.com>
Cc: KP Singh <kpsingh@kernel.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Szabolcs Nagy <Szabolcs.Nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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do/while_each_thread should be avoided when possible.
Plus this change allows to avoid lock_task_sighand(), we can use rcu
and/or sig->stats_lock instead.
Link: https://lkml.kernel.org/r/20230909172629.GA20454@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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No functional changes, cleanup/preparation.
Link: https://lkml.kernel.org/r/20230909172554.GA20441@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Somehow PR_GET_AUXV got added into PR_MCE_KILL's switch when the patch was
applied [1].
Thus move it out of the switch, to the place the patch added it.
In the recently released v6.4 kernel some user could, in principle, be
already using this feature by mapping the right page and passing the
PR_GET_AUXV constant as a pointer:
prctl(PR_MCE_KILL, PR_GET_AUXV, ...)
So this does change the behavior for users. We could keep the bug since
the other subcases in PR_MCE_KILL (PR_MCE_KILL_CLEAR and PR_MCE_KILL_SET)
do not overlap.
However, v6.4 may be recent enough (2 weeks old) that moving the lines
(rather than just adding a new case) does not break anybody? Moreover,
the documentation in man-pages was just committed today [2].
Link: https://lkml.kernel.org/r/20230708233344.361854-1-ojeda@kernel.org
Fixes: ddc65971bb67 ("prctl: add PR_GET_AUXV to copy auxv to userspace")
Link: https://lore.kernel.org/all/d81864a7f7f43bca6afa2a09fc2e850e4050ab42.1680611394.git.josh@joshtriplett.org/ [1]
Link: https://git.kernel.org/pub/scm/docs/man-pages/man-pages.git/commit/?id=8cf0c06bfd3c2b219b044d4151c96f0da50af9ad [2]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This patch add two riscv-specific prctls, to allow usespace control the
use of vector unit:
* PR_RISCV_V_SET_CONTROL: control the permission to use Vector at next,
or all following execve for a thread. Turning off a thread's Vector
live is not possible since libraries may have registered ifunc that
may execute Vector instructions.
* PR_RISCV_V_GET_CONTROL: get the same permission setting for the
current thread, and the setting for following execve(s).
Signed-off-by: Andy Chiu <andy.chiu@sifive.com>
Reviewed-by: Greentime Hu <greentime.hu@sifive.com>
Reviewed-by: Vincent Chen <vincent.chen@sifive.com>
Link: https://lore.kernel.org/r/20230605110724.21391-22-andy.chiu@sifive.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
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Patch series "mm/ksm: improve PR_SET_MEMORY_MERGE=0 handling and cleanup
disabling KSM", v2.
(1) Make PR_SET_MEMORY_MERGE=0 unmerge pages like setting MADV_UNMERGEABLE
does, (2) add a selftest for it and (3) factor out disabling of KSM from
s390/gmap code.
This patch (of 3):
Let's unmerge any KSM pages when setting PR_SET_MEMORY_MERGE=0, and clear
the VM_MERGEABLE flag from all VMAs -- just like KSM would. Of course,
only do that if we previously set PR_SET_MEMORY_MERGE=1.
Link: https://lkml.kernel.org/r/20230422205420.30372-1-david@redhat.com
Link: https://lkml.kernel.org/r/20230422205420.30372-2-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Acked-by: Stefan Roesch <shr@devkernel.io>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Janosch Frank <frankja@linux.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Patch series "mm: process/cgroup ksm support", v9.
So far KSM can only be enabled by calling madvise for memory regions. To
be able to use KSM for more workloads, KSM needs to have the ability to be
enabled / disabled at the process / cgroup level.
Use case 1:
The madvise call is not available in the programming language. An
example for this are programs with forked workloads using a garbage
collected language without pointers. In such a language madvise cannot
be made available.
In addition the addresses of objects get moved around as they are
garbage collected. KSM sharing needs to be enabled "from the outside"
for these type of workloads.
Use case 2:
The same interpreter can also be used for workloads where KSM brings
no benefit or even has overhead. We'd like to be able to enable KSM on
a workload by workload basis.
Use case 3:
With the madvise call sharing opportunities are only enabled for the
current process: it is a workload-local decision. A considerable number
of sharing opportunities may exist across multiple workloads or jobs (if
they are part of the same security domain). Only a higler level entity
like a job scheduler or container can know for certain if its running
one or more instances of a job. That job scheduler however doesn't have
the necessary internal workload knowledge to make targeted madvise
calls.
Security concerns:
In previous discussions security concerns have been brought up. The
problem is that an individual workload does not have the knowledge about
what else is running on a machine. Therefore it has to be very
conservative in what memory areas can be shared or not. However, if the
system is dedicated to running multiple jobs within the same security
domain, its the job scheduler that has the knowledge that sharing can be
safely enabled and is even desirable.
Performance:
Experiments with using UKSM have shown a capacity increase of around 20%.
Here are the metrics from an instagram workload (taken from a machine
with 64GB main memory):
full_scans: 445
general_profit: 20158298048
max_page_sharing: 256
merge_across_nodes: 1
pages_shared: 129547
pages_sharing: 5119146
pages_to_scan: 4000
pages_unshared: 1760924
pages_volatile: 10761341
run: 1
sleep_millisecs: 20
stable_node_chains: 167
stable_node_chains_prune_millisecs: 2000
stable_node_dups: 2751
use_zero_pages: 0
zero_pages_sharing: 0
After the service is running for 30 minutes to an hour, 4 to 5 million
shared pages are common for this workload when using KSM.
Detailed changes:
1. New options for prctl system command
This patch series adds two new options to the prctl system call.
The first one allows to enable KSM at the process level and the second
one to query the setting.
The setting will be inherited by child processes.
With the above setting, KSM can be enabled for the seed process of a cgroup
and all processes in the cgroup will inherit the setting.
2. Changes to KSM processing
When KSM is enabled at the process level, the KSM code will iterate
over all the VMA's and enable KSM for the eligible VMA's.
When forking a process that has KSM enabled, the setting will be
inherited by the new child process.
3. Add general_profit metric
The general_profit metric of KSM is specified in the documentation,
but not calculated. This adds the general profit metric to
/sys/kernel/debug/mm/ksm.
4. Add more metrics to ksm_stat
This adds the process profit metric to /proc/<pid>/ksm_stat.
5. Add more tests to ksm_tests and ksm_functional_tests
This adds an option to specify the merge type to the ksm_tests.
This allows to test madvise and prctl KSM.
It also adds a two new tests to ksm_functional_tests: one to test
the new prctl options and the other one is a fork test to verify that
the KSM process setting is inherited by client processes.
This patch (of 3):
So far KSM can only be enabled by calling madvise for memory regions. To
be able to use KSM for more workloads, KSM needs to have the ability to be
enabled / disabled at the process / cgroup level.
1. New options for prctl system command
This patch series adds two new options to the prctl system call.
The first one allows to enable KSM at the process level and the second
one to query the setting.
The setting will be inherited by child processes.
With the above setting, KSM can be enabled for the seed process of a
cgroup and all processes in the cgroup will inherit the setting.
2. Changes to KSM processing
When KSM is enabled at the process level, the KSM code will iterate
over all the VMA's and enable KSM for the eligible VMA's.
When forking a process that has KSM enabled, the setting will be
inherited by the new child process.
1) Introduce new MMF_VM_MERGE_ANY flag
This introduces the new flag MMF_VM_MERGE_ANY flag. When this flag
is set, kernel samepage merging (ksm) gets enabled for all vma's of a
process.
2) Setting VM_MERGEABLE on VMA creation
When a VMA is created, if the MMF_VM_MERGE_ANY flag is set, the
VM_MERGEABLE flag will be set for this VMA.
3) support disabling of ksm for a process
This adds the ability to disable ksm for a process if ksm has been
enabled for the process with prctl.
4) add new prctl option to get and set ksm for a process
This adds two new options to the prctl system call
- enable ksm for all vmas of a process (if the vmas support it).
- query if ksm has been enabled for a process.
3. Disabling MMF_VM_MERGE_ANY for storage keys in s390
In the s390 architecture when storage keys are used, the
MMF_VM_MERGE_ANY will be disabled.
Link: https://lkml.kernel.org/r/20230418051342.1919757-1-shr@devkernel.io
Link: https://lkml.kernel.org/r/20230418051342.1919757-2-shr@devkernel.io
Signed-off-by: Stefan Roesch <shr@devkernel.io>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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If a library wants to get information from auxv (for instance,
AT_HWCAP/AT_HWCAP2), it has a few options, none of them perfectly reliable
or ideal:
- Be main or the pre-main startup code, and grub through the stack above
main. Doesn't work for a library.
- Call libc getauxval. Not ideal for libraries that are trying to be
libc-independent and/or don't otherwise require anything from other
libraries.
- Open and read /proc/self/auxv. Doesn't work for libraries that may run
in arbitrarily constrained environments that may not have /proc
mounted (e.g. libraries that might be used by an init program or a
container setup tool).
- Assume you're on the main thread and still on the original stack, and
try to walk the stack upwards, hoping to find auxv. Extremely bad
idea.
- Ask the caller to pass auxv in for you. Not ideal for a user-friendly
library, and then your caller may have the same problem.
Add a prctl that copies current->mm->saved_auxv to a userspace buffer.
Link: https://lkml.kernel.org/r/d81864a7f7f43bca6afa2a09fc2e850e4050ab42.1680611394.git.josh@joshtriplett.org
Signed-off-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Linux Security Modules (LSMs) that implement the "capable" hook will
usually emit an access denial message to the audit log whenever they
"block" the current task from using the given capability based on their
security policy.
The occurrence of a denial is used as an indication that the given task
has attempted an operation that requires the given access permission, so
the callers of functions that perform LSM permission checks must take care
to avoid calling them too early (before it is decided if the permission is
actually needed to perform the requested operation).
The __sys_setres[ug]id() functions violate this convention by first
calling ns_capable_setid() and only then checking if the operation
requires the capability or not. It means that any caller that has the
capability granted by DAC (task's capability set) but not by MAC (LSMs)
will generate a "denied" audit record, even if is doing an operation for
which the capability is not required.
Fix this by reordering the checks such that ns_capable_setid() is checked
last and -EPERM is returned immediately if it returns false.
While there, also do two small optimizations:
* move the capability check before prepare_creds() and
* bail out early in case of a no-op.
Link: https://lkml.kernel.org/r/20230217162154.837549-1-omosnace@redhat.com
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Daniel Verkamp has contributed a memfd series ("mm/memfd: add
F_SEAL_EXEC") which permits the setting of the memfd execute bit at
memfd creation time, with the option of sealing the state of the X
bit.
- Peter Xu adds a patch series ("mm/hugetlb: Make huge_pte_offset()
thread-safe for pmd unshare") which addresses a rare race condition
related to PMD unsharing.
- Several folioification patch serieses from Matthew Wilcox, Vishal
Moola, Sidhartha Kumar and Lorenzo Stoakes
- Johannes Weiner has a series ("mm: push down lock_page_memcg()")
which does perform some memcg maintenance and cleanup work.
- SeongJae Park has added DAMOS filtering to DAMON, with the series
"mm/damon/core: implement damos filter".
These filters provide users with finer-grained control over DAMOS's
actions. SeongJae has also done some DAMON cleanup work.
- Kairui Song adds a series ("Clean up and fixes for swap").
- Vernon Yang contributed the series "Clean up and refinement for maple
tree".
- Yu Zhao has contributed the "mm: multi-gen LRU: memcg LRU" series. It
adds to MGLRU an LRU of memcgs, to improve the scalability of global
reclaim.
- David Hildenbrand has added some userfaultfd cleanup work in the
series "mm: uffd-wp + change_protection() cleanups".
- Christoph Hellwig has removed the generic_writepages() library
function in the series "remove generic_writepages".
- Baolin Wang has performed some maintenance on the compaction code in
his series "Some small improvements for compaction".
- Sidhartha Kumar is doing some maintenance work on struct page in his
series "Get rid of tail page fields".
- David Hildenbrand contributed some cleanup, bugfixing and
generalization of pte management and of pte debugging in his series
"mm: support __HAVE_ARCH_PTE_SWP_EXCLUSIVE on all architectures with
swap PTEs".
- Mel Gorman and Neil Brown have removed the __GFP_ATOMIC allocation
flag in the series "Discard __GFP_ATOMIC".
- Sergey Senozhatsky has improved zsmalloc's memory utilization with
his series "zsmalloc: make zspage chain size configurable".
- Joey Gouly has added prctl() support for prohibiting the creation of
writeable+executable mappings.
The previous BPF-based approach had shortcomings. See "mm: In-kernel
support for memory-deny-write-execute (MDWE)".
- Waiman Long did some kmemleak cleanup and bugfixing in the series
"mm/kmemleak: Simplify kmemleak_cond_resched() & fix UAF".
- T.J. Alumbaugh has contributed some MGLRU cleanup work in his series
"mm: multi-gen LRU: improve".
- Jiaqi Yan has provided some enhancements to our memory error
statistics reporting, mainly by presenting the statistics on a
per-node basis. See the series "Introduce per NUMA node memory error
statistics".
- Mel Gorman has a second and hopefully final shot at fixing a CPU-hog
regression in compaction via his series "Fix excessive CPU usage
during compaction".
- Christoph Hellwig does some vmalloc maintenance work in the series
"cleanup vfree and vunmap".
- Christoph Hellwig has removed block_device_operations.rw_page() in
ths series "remove ->rw_page".
- We get some maple_tree improvements and cleanups in Liam Howlett's
series "VMA tree type safety and remove __vma_adjust()".
- Suren Baghdasaryan has done some work on the maintainability of our
vm_flags handling in the series "introduce vm_flags modifier
functions".
- Some pagemap cleanup and generalization work in Mike Rapoport's
series "mm, arch: add generic implementation of pfn_valid() for
FLATMEM" and "fixups for generic implementation of pfn_valid()"
- Baoquan He has done some work to make /proc/vmallocinfo and
/proc/kcore better represent the real state of things in his series
"mm/vmalloc.c: allow vread() to read out vm_map_ram areas".
- Jason Gunthorpe rationalized the GUP system's interface to the rest
of the kernel in the series "Simplify the external interface for
GUP".
- SeongJae Park wishes to migrate people from DAMON's debugfs interface
over to its sysfs interface. To support this, we'll temporarily be
printing warnings when people use the debugfs interface. See the
series "mm/damon: deprecate DAMON debugfs interface".
- Andrey Konovalov provided the accurately named "lib/stackdepot: fixes
and clean-ups" series.
- Huang Ying has provided a dramatic reduction in migration's TLB flush
IPI rates with the series "migrate_pages(): batch TLB flushing".
- Arnd Bergmann has some objtool fixups in "objtool warning fixes".
* tag 'mm-stable-2023-02-20-13-37' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (505 commits)
include/linux/migrate.h: remove unneeded externs
mm/memory_hotplug: cleanup return value handing in do_migrate_range()
mm/uffd: fix comment in handling pte markers
mm: change to return bool for isolate_movable_page()
mm: hugetlb: change to return bool for isolate_hugetlb()
mm: change to return bool for isolate_lru_page()
mm: change to return bool for folio_isolate_lru()
objtool: add UACCESS exceptions for __tsan_volatile_read/write
kmsan: disable ftrace in kmsan core code
kasan: mark addr_has_metadata __always_inline
mm: memcontrol: rename memcg_kmem_enabled()
sh: initialize max_mapnr
m68k/nommu: add missing definition of ARCH_PFN_OFFSET
mm: percpu: fix incorrect size in pcpu_obj_full_size()
maple_tree: reduce stack usage with gcc-9 and earlier
mm: page_alloc: call panic() when memoryless node allocation fails
mm: multi-gen LRU: avoid futile retries
migrate_pages: move THP/hugetlb migration support check to simplify code
migrate_pages: batch flushing TLB
migrate_pages: share more code between _unmap and _move
...
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Patch series "mm: In-kernel support for memory-deny-write-execute (MDWE)",
v2.
The background to this is that systemd has a configuration option called
MemoryDenyWriteExecute [2], implemented as a SECCOMP BPF filter. Its aim
is to prevent a user task from inadvertently creating an executable
mapping that is (or was) writeable. Since such BPF filter is stateless,
it cannot detect mappings that were previously writeable but subsequently
changed to read-only. Therefore the filter simply rejects any
mprotect(PROT_EXEC). The side-effect is that on arm64 with BTI support
(Branch Target Identification), the dynamic loader cannot change an ELF
section from PROT_EXEC to PROT_EXEC|PROT_BTI using mprotect(). For
libraries, it can resort to unmapping and re-mapping but for the main
executable it does not have a file descriptor. The original bug report in
the Red Hat bugzilla - [3] - and subsequent glibc workaround for libraries
- [4].
This series adds in-kernel support for this feature as a prctl
PR_SET_MDWE, that is inherited on fork(). The prctl denies PROT_WRITE |
PROT_EXEC mappings. Like the systemd BPF filter it also denies adding
PROT_EXEC to mappings. However unlike the BPF filter it only denies it if
the mapping didn't previous have PROT_EXEC. This allows to PROT_EXEC ->
PROT_EXEC | PROT_BTI with mprotect(), which is a problem with the BPF
filter.
This patch (of 2):
The aim of such policy is to prevent a user task from creating an
executable mapping that is also writeable.
An example of mmap() returning -EACCESS if the policy is enabled:
mmap(0, size, PROT_READ | PROT_WRITE | PROT_EXEC, flags, 0, 0);
Similarly, mprotect() would return -EACCESS below:
addr = mmap(0, size, PROT_READ | PROT_EXEC, flags, 0, 0);
mprotect(addr, size, PROT_READ | PROT_WRITE | PROT_EXEC);
The BPF filter that systemd MDWE uses is stateless, and disallows
mprotect() with PROT_EXEC completely. This new prctl allows PROT_EXEC to
be enabled if it was already PROT_EXEC, which allows the following case:
addr = mmap(0, size, PROT_READ | PROT_EXEC, flags, 0, 0);
mprotect(addr, size, PROT_READ | PROT_EXEC | PROT_BTI);
where PROT_BTI enables branch tracking identification on arm64.
Link: https://lkml.kernel.org/r/20230119160344.54358-1-joey.gouly@arm.com
Link: https://lkml.kernel.org/r/20230119160344.54358-2-joey.gouly@arm.com
Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jeremy Linton <jeremy.linton@arm.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Lennart Poettering <lennart@poettering.net>
Cc: Mark Brown <broonie@kernel.org>
Cc: nd <nd@arm.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Topi Miettinen <toiwoton@gmail.com>
Cc: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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do_prlimit() adds the user-controlled resource value to a pointer that
will subsequently be dereferenced. In order to help prevent this
codepath from being used as a spectre "gadget" a barrier needs to be
added after checking the range.
Reported-by: Jordy Zomer <jordyzomer@google.com>
Tested-by: Jordy Zomer <jordyzomer@google.com>
Suggested-by: Linus Torvalds <torvalds@linuxfoundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull random number generator updates from Jason Donenfeld:
- Huawei reported that when they updated their kernel from 4.4 to
something much newer, some userspace code they had broke, the culprit
being the accidental removal of O_NONBLOCK from /dev/random way back
in 5.6. It's been gone for over 2 years now and this is the first
we've heard of it, but user |