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2021-06-14bpf: Do not mark insn as seen under speculative path verificationDaniel Borkmann
... in such circumstances, we do not want to mark the instruction as seen given the goal is still to jmp-1 rewrite/sanitize dead code, if it is not reachable from the non-speculative path verification. We do however want to verify it for safety regardless. With the patch as-is all the insns that have been marked as seen before the patch will also be marked as seen after the patch (just with a potentially different non-zero count). An upcoming patch will also verify paths that are unreachable in the non-speculative domain, hence this extension is needed. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de> Reviewed-by: Piotr Krysiuk <piotras@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-06-14bpf: Inherit expanded/patched seen count from old aux dataDaniel Borkmann
Instead of relying on current env->pass_cnt, use the seen count from the old aux data in adjust_insn_aux_data(), and expand it to the new range of patched instructions. This change is valid given we always expand 1:n with n>=1, so what applies to the old/original instruction needs to apply for the replacement as well. Not relying on env->pass_cnt is a prerequisite for a later change where we want to avoid marking an instruction seen when verified under speculative execution path. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Reviewed-by: Benedict Schlueter <benedict.schlueter@rub.de> Reviewed-by: Piotr Krysiuk <piotras@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
2021-06-14sched/fair: Correctly insert cfs_rq's to list on unthrottleOdin Ugedal
Fix an issue where fairness is decreased since cfs_rq's can end up not being decayed properly. For two sibling control groups with the same priority, this can often lead to a load ratio of 99/1 (!!). This happens because when a cfs_rq is throttled, all the descendant cfs_rq's will be removed from the leaf list. When they initial cfs_rq is unthrottled, it will currently only re add descendant cfs_rq's if they have one or more entities enqueued. This is not a perfect heuristic. Instead, we insert all cfs_rq's that contain one or more enqueued entities, or it its load is not completely decayed. Can often lead to situations like this for equally weighted control groups: $ ps u -C stress USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND root 10009 88.8 0.0 3676 100 pts/1 R+ 11:04 0:13 stress --cpu 1 root 10023 3.0 0.0 3676 104 pts/1 R+ 11:04 0:00 stress --cpu 1 Fixes: 31bc6aeaab1d ("sched/fair: Optimize update_blocked_averages()") [vingo: !SMP build fix] Signed-off-by: Odin Ugedal <odin@uged.al> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20210612112815.61678-1-odin@uged.al
2021-06-14Revert "cpufreq: CPPC: Add support for frequency invariance"Viresh Kumar
This reverts commit 4c38f2df71c8e33c0b64865992d693f5022eeaad. There are few races in the frequency invariance support for CPPC driver, namely the driver doesn't stop the kthread_work and irq_work on policy exit during suspend/resume or CPU hotplug. A proper fix won't be possible for the 5.13-rc, as it requires a lot of changes. Lets revert the patch instead for now. Fixes: 4c38f2df71c8 ("cpufreq: CPPC: Add support for frequency invariance") Reported-by: Qian Cai <quic_qiancai@quicinc.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-12Merge tag 'sched-urgent-2021-06-12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler fixes from Ingo Molnar: "Misc fixes: - Fix performance regression caused by lack of intended batching of RCU callbacks by over-eager NOHZ-full code. - Fix cgroups related corruption of load_avg and load_sum metrics. - Three fixes to fix blocked load, util_sum/runnable_sum and util_est tracking bugs" * tag 'sched-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: sched/fair: Fix util_est UTIL_AVG_UNCHANGED handling sched/pelt: Ensure that *_sum is always synced with *_avg tick/nohz: Only check for RCU deferred wakeup on user/guest entry when needed sched/fair: Make sure to update tg contrib for blocked load sched/fair: Keep load_avg and load_sum synced
2021-06-12Merge tag 'perf-urgent-2021-06-12' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Misc fixes: - Fix the NMI watchdog on ancient Intel CPUs - Remove a misguided, NMI-unsafe KASAN callback from the NMI-safe irq_work path used by perf. - Fix uncore events on Ice Lake servers. - Someone booted maxcpus=1 on an SNB-EP, and the uncore driver emitted warnings and was probably buggy. Fix it. - KCSAN found a genuine data race in the core perf code. Somewhat ironically the bug was introduced through a recent race fix. :-/ In our defense, the new race window was much more narrow. Fix it" * tag 'perf-urgent-2021-06-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/nmi_watchdog: Fix old-style NMI watchdog regression on old Intel CPUs irq_work: Make irq_work_queue() NMI-safe again perf/x86/intel/uncore: Fix M2M event umask for Ice Lake server perf/x86/intel/uncore: Fix a kernel WARNING triggered by maxcpus=1 perf: Fix data race between pin_count increment/decrement
2021-06-11Merge tag 'trace-v5.13-rc5-2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: - Fix the length check in the temp buffer filter - Fix build failure in bootconfig tools for "fallthrough" macro - Fix error return of bootconfig apply_xbc() routine * tag 'trace-v5.13-rc5-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Correct the length check which causes memory corruption ftrace: Do not blindly read the ip address in ftrace_bug() tools/bootconfig: Fix a build error accroding to undefined fallthrough tools/bootconfig: Fix error return code in apply_xbc()
2021-06-11PM: hibernate: remove leading spaces before tabsZhen Lei
1) Run the following command to find and remove the leading spaces before tabs: $ find kernel/power/ -type f | xargs sed -r -i 's/^[ ]+\t/\t/' 2) Manually check and correct if necessary Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-11PM: sleep: remove trailing spaces and tabsZhen Lei
Run the following command to find and remove the trailing spaces and tabs: $ find kernel/power/ -type f | xargs sed -r -i 's/[ \t]+$//' Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2021-06-10audit: remove trailing spaces and tabsZhen Lei
Run the following command to find and remove the trailing spaces and tabs: sed -r -i 's/[ \t]+$//' <audit_files> The files to be checked are as follows: kernel/audit* include/linux/audit.h include/uapi/linux/audit.h Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-06-10Merge branch 'for-5.13-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fix from Tejun Heo: "This is a high priority but low risk fix for a cgroup1 bug where rename(2) can change a cgroup's name to something which can break parsing of /proc/PID/cgroup" * 'for-5.13-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup1: don't allow '\n' in renaming
2021-06-10tracing: Add better comments for the filtering temp buffer use caseSteven Rostedt (VMware)
When filtering is enabled, the event is copied into a temp buffer instead of being written into the ring buffer directly, because the discarding of events from the ring buffer is very expensive, and doing the extra copy is much faster than having to discard most of the time. As that logic is subtle, add comments to explain in more detail to what is going on and how it works. Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10tracing: Simplify the max length test when using the filtering temp bufferSteven Rostedt (VMware)
When filtering trace events, a temp buffer is used because the extra copy from the temp buffer into the ring buffer is still faster than the direct write into the ring buffer followed by a discard if the filter does not match. But the data that can be stored in the temp buffer is a PAGE_SIZE minus the ring buffer event header. The calculation of that header size is complex, but using the helper macro "struct_size()" can simplify it. Link: https://lore.kernel.org/stable/CAHk-=whKbJkuVmzb0hD3N6q7veprUrSpiBHRxVY=AffWZPtxmg@mail.gmail.com/ Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10tracing/boot: Add per-group/all events enablementMasami Hiramatsu
Add ftrace.event.<GROUP>.enable and ftrace.event.enable boot-time tracing, which enables all events under given GROUP and all events respectivly. Link: https://lkml.kernel.org/r/162264438005.302580.12019174481201855444.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10tracing: Add WARN_ON_ONCE when returned value is negativeHyeonggon Yoo
ret is assigned return value of event_hist_trigger_func, but the value is unused. It is better to warn when returned value is negative, rather than just ignoring it. Link: https://lkml.kernel.org/r/20210529061423.GA103954@hyeyoo Signed-off-by: Hyeonggon Yoo <42.hyeyoo@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10tracing: Fix set_named_trigger_data() kernel-doc commentQiujun Huang
Fix the description of the parameters. Link: https://lkml.kernel.org/r/20210515105735.52785-1-hqjagain@gmail.com Signed-off-by: Qiujun Huang <hqjagain@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10tracing: Remove redundant initialization of variable retColin Ian King
The variable ret is being initialized with a value that is never read, it is being updated later on. The assignment is redundant and can be removed. Link: https://lkml.kernel.org/r/20210513115517.58178-1-colin.king@canonical.com Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10ring-buffer: Use fallthrough pseudo-keywordWei Ming Chen
Replace /* fall through */ comment with pseudo-keyword macro fallthrough[1] [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Link: https://lkml.kernel.org/r/20210511140246.18868-1-jj251510319013@gmail.com Signed-off-by: Wei Ming Chen <jj251510319013@gmail.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10tracing: Remove redundant assignment to event_varJiapeng Chong
Variable event_var is set to 'ERR_PTR(-EINVAL)', but this value is never read as it is overwritten or not used later on, hence it is a redundant assignment and can be removed. Clean up the following clang-analyzer warning: kernel/trace/trace_events_hist.c:2437:21: warning: Value stored to 'event_var' during its initialization is never read [clang-analyzer-deadcode.DeadStores]. Link: https://lkml.kernel.org/r/1620470236-26562-1-git-send-email-jiapeng.chong@linux.alibaba.com Reported-by: Abaci Robot <abaci@linux.alibaba.com> Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-10scsi: cgroup: Add cgroup_get_from_id()Muneendra Kumar
Add a new function, cgroup_get_from_id(), to retrieve the cgroup associated with a cgroup id. Also export the function cgroup_get_e_css() as this is needed in blk-cgroup.h. Link: https://lore.kernel.org/r/20210608043556.274139-2-muneendra.kumar@broadcom.com Reviewed-by: Himanshu Madhani <himanshu.madhani@oracle.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Muneendra Kumar <muneendra.kumar@broadcom.com> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2021-06-10cgroup1: don't allow '\n' in renamingAlexander Kuznetsov
cgroup_mkdir() have restriction on newline usage in names: $ mkdir $'/sys/fs/cgroup/cpu/test\ntest2' mkdir: cannot create directory '/sys/fs/cgroup/cpu/test\ntest2': Invalid argument But in cgroup1_rename() such check is missed. This allows us to make /proc/<pid>/cgroup unparsable: $ mkdir /sys/fs/cgroup/cpu/test $ mv /sys/fs/cgroup/cpu/test $'/sys/fs/cgroup/cpu/test\ntest2' $ echo $$ > $'/sys/fs/cgroup/cpu/test\ntest2' $ cat /proc/self/cgroup 11:pids:/ 10:freezer:/ 9:hugetlb:/ 8:cpuset:/ 7:blkio:/user.slice 6:memory:/user.slice 5:net_cls,net_prio:/ 4:perf_event:/ 3:devices:/user.slice 2:cpu,cpuacct:/test test2 1:name=systemd:/ 0::/ Signed-off-by: Alexander Kuznetsov <wwfq@yandex-team.ru> Reported-by: Andrey Krasichkov <buglloc@yandex-team.ru> Acked-by: Dmitry Yakunin <zeil@yandex-team.ru> Cc: stable@vger.kernel.org Signed-off-by: Tejun Heo <tj@kernel.org>
2021-06-10genirq: Move non-irqdomain handle_domain_irq() handling into ARM's handle_IRQ()Marc Zyngier
Despite the name, handle_domain_irq() deals with non-irqdomain handling for the sake of a handful of legacy ARM platforms. Move such handling into ARM's handle_IRQ(), allowing for better code generation for everyone else. This allows us get rid of some complexity, and to rearrange the guards on the various helpers in a more logical way. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10genirq: Add generic_handle_domain_irq() helperMarc Zyngier
Provide generic_handle_domain_irq() as a pendent to handle_domain_irq() for non-root interrupt controllers Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10genirq: Use irq_resolve_mapping() to implement __handle_domain_irq() and coMarc Zyngier
In order to start reaping the benefits of irq_resolve_mapping(), start using it in __handle_domain_irq() and handle_domain_nmi(). This involves splitting generic_handle_irq() to be able to directly provide the irq_desc. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irqdomain: Introduce irq_resolve_mapping()Marc Zyngier
Rework irq_find_mapping() to return an both an irq_desc pointer, optionally the virtual irq number, and rename the result to __irq_resolve_mapping(). a new helper called irq_resolve_mapping() is provided for code that doesn't need the virtual irq number. irq_find_mapping() is also rewritten in terms of __irq_resolve_mapping(). Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irqdomain: Protect the linear revmap with RCUMarc Zyngier
It is pretty odd that the radix tree uses RCU while the linear portion doesn't, leading to potential surprises for the users, depending on how the irqdomain has been created. Fix this by moving the update of the linear revmap under the mutex, and the lookup under the RCU read-side lock. The mutex name is updated to reflect that it doesn't only cover the radix-tree anymore. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irqdomain: Cache irq_data instead of a virq number in the revmapMarc Zyngier
Caching a virq number in the revmap is pretty inefficient, as it means we will need to convert it back to either an irq_data or irq_desc to do anything with it. It is also a bit odd, as the radix tree does cache irq_data pointers. Change the revmap type to be an irq_data pointer instead of an unsigned int, and preserve the current API for now. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irqdomain: Use struct_size() helper when allocating irqdomainMarc Zyngier
Instead of open-coding the size computation of struct irqdomain, use the struct_size() helper instead. This is going to be handy as we change the type of the revmap array. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irqdomain: Make normal and nomap irqdomains exclusiveMarc Zyngier
Direct mappings are completely exclusive of normal mappings, meaning that we can refactor the code slightly so that we can get rid of the revmap_direct_max_irq field and use the revmap_size field instead, reducing the size of the irqdomain structure. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10powerpc: Move the use of irq_domain_add_nomap() behind a config optionMarc Zyngier
Only a handful of old PPC systems are still using the old 'nomap' variant of the irqdomain library. Move the associated definitions behind a configuration option, which will allow us to make some more radical changes. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irqdomain: Reimplement irq_linear_revmap() with irq_find_mapping()Marc Zyngier
irq_linear_revmap() is supposed to be a fast path for domain lookups, but it only exposes low-level details of the irqdomain implementation, details which are better kept private. The *overhead* between the two is only a function call and a couple of tests, so it is likely that noone can show any meaningful difference compared to the cost of taking an interrupt. Reimplement irq_linear_revmap() with irq_find_mapping() in order to preserve source code compatibility, and rename the internal field for a measure. Signed-off-by: Marc Zyngier <maz@kernel.org>
2021-06-10irq_work: Make irq_work_queue() NMI-safe againPeter Zijlstra
Someone carelessly put NMI unsafe code in irq_work_queue(), breaking just about every single user. Also, someone has a terrible comment style. Fixes: e2b5bcf9f5ba ("irq_work: record irq_work_queue() call stack") Reported-by: Alexander Shishkin <alexander.shishkin@linux.intel.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/YL+uBq8LzXXZsYVf@hirez.programming.kicks-ass.net
2021-06-08audit: Use list_move instead of list_del/list_addBaokun Li
Using list_move() instead of list_del() + list_add(). Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-06-08audit: Rename enum audit_state constants to avoid AUDIT_DISABLED redefinitionSergey Nazarov
AUDIT_DISABLED defined in kernel/audit.h as element of enum audit_state and redefined in kernel/audit.c. This produces a warning when kernel builds with syscalls audit disabled and brokes kernel build if -Werror used. enum audit_state used in syscall audit code only. This patch changes enum audit_state constants prefix AUDIT to AUDIT_STATE to avoid AUDIT_DISABLED redefinition. Signed-off-by: Sergey Nazarov <s-nazarov@yandex.ru> Acked-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-06-08rq-qos: fix missed wake-ups in rq_qos_throttle try twoJan Kara
Commit 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") tried to fix a problem that a process could be sleeping in rq_qos_wait() without anyone to wake it up. However the fix is not complete and the following can still happen: CPU1 (waiter1) CPU2 (waiter2) CPU3 (waker) rq_qos_wait() rq_qos_wait() acquire_inflight_cb() -> fails acquire_inflight_cb() -> fails completes IOs, inflight decreased prepare_to_wait_exclusive() prepare_to_wait_exclusive() has_sleeper = !wq_has_single_sleeper() -> true as there are two sleepers has_sleeper = !wq_has_single_sleeper() -> true io_schedule() io_schedule() Deadlock as now there's nobody to wakeup the two waiters. The logic automatically blocking when there are already sleepers is really subtle and the only way to make it work reliably is that we check whether there are some waiters in the queue when adding ourselves there. That way, we are guaranteed that at least the first process to enter the wait queue will recheck the waiting condition before going to sleep and thus guarantee forward progress. Fixes: 545fbd0775ba ("rq-qos: fix missed wake-ups in rq_qos_throttle") CC: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20210607112613.25344-1-jack@suse.cz Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-06-08tracing: Correct the length check which causes memory corruptionLiangyan
We've suffered from severe kernel crashes due to memory corruption on our production environment, like, Call Trace: [1640542.554277] general protection fault: 0000 [#1] SMP PTI [1640542.554856] CPU: 17 PID: 26996 Comm: python Kdump: loaded Tainted:G [1640542.556629] RIP: 0010:kmem_cache_alloc+0x90/0x190 [1640542.559074] RSP: 0018:ffffb16faa597df8 EFLAGS: 00010286 [1640542.559587] RAX: 0000000000000000 RBX: 0000000000400200 RCX: 0000000006e931bf [1640542.560323] RDX: 0000000006e931be RSI: 0000000000400200 RDI: ffff9a45ff004300 [1640542.560996] RBP: 0000000000400200 R08: 0000000000023420 R09: 0000000000000000 [1640542.561670] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff9a20608d [1640542.562366] R13: ffff9a45ff004300 R14: ffff9a45ff004300 R15: 696c662f65636976 [1640542.563128] FS: 00007f45d7c6f740(0000) GS:ffff9a45ff840000(0000) knlGS:0000000000000000 [1640542.563937] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [1640542.564557] CR2: 00007f45d71311a0 CR3: 000000189d63e004 CR4: 00000000003606e0 [1640542.565279] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [1640542.566069] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [1640542.566742] Call Trace: [1640542.567009] anon_vma_clone+0x5d/0x170 [1640542.567417] __split_vma+0x91/0x1a0 [1640542.567777] do_munmap+0x2c6/0x320 [1640542.568128] vm_munmap+0x54/0x70 [1640542.569990] __x64_sys_munmap+0x22/0x30 [1640542.572005] do_syscall_64+0x5b/0x1b0 [1640542.573724] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [1640542.575642] RIP: 0033:0x7f45d6e61e27 James Wang has reproduced it stably on the latest 4.19 LTS. After some debugging, we finally proved that it's due to ftrace buffer out-of-bound access using a debug tool as follows: [ 86.775200] BUG: Out-of-bounds write at addr 0xffff88aefe8b7000 [ 86.780806] no_context+0xdf/0x3c0 [ 86.784327] __do_page_fault+0x252/0x470 [ 86.788367] do_page_fault+0x32/0x140 [ 86.792145] page_fault+0x1e/0x30 [ 86.795576] strncpy_from_unsafe+0x66/0xb0 [ 86.799789] fetch_memory_string+0x25/0x40 [ 86.804002] fetch_deref_string+0x51/0x60 [ 86.808134] kprobe_trace_func+0x32d/0x3a0 [ 86.812347] kprobe_dispatcher+0x45/0x50 [ 86.816385] kprobe_ftrace_handler+0x90/0xf0 [ 86.820779] ftrace_ops_assist_func+0xa1/0x140 [ 86.825340] 0xffffffffc00750bf [ 86.828603] do_sys_open+0x5/0x1f0 [ 86.832124] do_syscall_64+0x5b/0x1b0 [ 86.835900] entry_SYSCALL_64_after_hwframe+0x44/0xa9 commit b220c049d519 ("tracing: Check length before giving out the filter buffer") adds length check to protect trace data overflow introduced in 0fc1b09ff1ff, seems that this fix can't prevent overflow entirely, the length check should also take the sizeof entry->array[0] into account, since this array[0] is filled the length of trace data and occupy addtional space and risk overflow. Link: https://lkml.kernel.org/r/20210607125734.1770447-1-liangyan.peng@linux.alibaba.com Cc: stable@vger.kernel.org Cc: Ingo Molnar <mingo@redhat.com> Cc: Xunlei Pang <xlpang@linux.alibaba.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Fixes: b220c049d519 ("tracing: Check length before giving out the filter buffer") Reviewed-by: Xunlei Pang <xlpang@linux.alibaba.com> Reviewed-by: yinbinbin <yinbinbin@alibabacloud.com> Reviewed-by: Wetp Zhang <wetp.zy@linux.alibaba.com> Tested-by: James Wang <jnwang@linux.alibaba.com> Signed-off-by: Liangyan <liangyan.peng@linux.alibaba.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-08ftrace: Do not blindly read the ip address in ftrace_bug()Steven Rostedt (VMware)
It was reported that a bug on arm64 caused a bad ip address to be used for updating into a nop in ftrace_init(), but the error path (rightfully) returned -EINVAL and not -EFAULT, as the bug caused more than one error to occur. But because -EINVAL was returned, the ftrace_bug() tried to report what was at the location of the ip address, and read it directly. This caused the machine to panic, as the ip was not pointing to a valid memory address. Instead, read the ip address with copy_from_kernel_nofault() to safely access the memory, and if it faults, report that the address faulted, otherwise report what was in that location. Link: https://lore.kernel.org/lkml/20210607032329.28671-1-mark-pk.tsai@mediatek.com/ Cc: stable@vger.kernel.org Fixes: 05736a427f7e1 ("ftrace: warn on failure to disable mcount callers") Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-08cgroup: make per-cgroup pressure stall tracking configurableSuren Baghdasaryan
PSI accounts stalls for each cgroup separately and aggregates it at each level of the hierarchy. This causes additional overhead with psi_avgs_work being called for each cgroup in the hierarchy. psi_avgs_work has been highly optimized, however on systems with large number of cgroups the overhead becomes noticeable. Systems which use PSI only at the system level could avoid this overhead if PSI can be configured to skip per-cgroup stall accounting. Add "cgroup_disable=pressure" kernel command-line option to allow requesting system-wide only pressure stall accounting. When set, it keeps system-wide accounting under /proc/pressure/ but skips accounting for individual cgroups and does not expose PSI nodes in cgroup hierarchy. Signed-off-by: Suren Baghdasaryan <surenb@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Signed-off-by: Tejun Heo <tj@kernel.org>
2021-06-07Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Bug fixes overlapping feature additions and refactoring, mostly. Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-07quota: Change quotactl_path() systcall to an fd-based oneJan Kara
Some users have pointed out that path-based syscalls are problematic in some environments and at least directory fd argument and possibly also resolve flags are desirable for such syscalls. Rather than reimplementing all details of pathname lookup and following where it may eventually evolve, let's go for full file descriptor based syscall similar to how ioctl(2) works since the beginning. Managing of quotas isn't performance sensitive so the extra overhead of open does not matter and we are able to consume O_PATH descriptors as well which makes open cheap anyway. Also for frequent operations (such as retrieving usage information for all users) we can reuse single fd and in fact get even better performance as well as avoiding races with possible remounts etc. Tested-by: Sascha Hauer <s.hauer@pengutronix.de> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2021-06-04Merge tag 'net-5.13-rc5' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net Pull networking fixes from Jakub Kicinski: "Networking fixes, including fixes from bpf, wireless, netfilter and wireguard trees. The bpf vs lockdown+audit fix is the most notable. Things haven't slowed down just yet, both in terms of regressions in current release and largish fixes for older code, but we usually see a slowdown only after -rc5. Current release - regressions: - virtio-net: fix page faults and crashes when XDP is enabled - mlx5e: fix HW timestamping with CQE compression, and make sure they are only allowed to coexist with capable devices - stmmac: - fix kernel panic due to NULL pointer dereference of mdio_bus_data - fix double clk unprepare when no PHY device is connected Current release - new code bugs: - mt76: a few fixes for the recent MT7921 devices and runtime power management Previous releases - regressions: - ice: - track AF_XDP ZC enabled queues in bitmap to fix copy mode Tx - fix allowing VF to request more/less queues via virtchnl - correct supported and advertised autoneg by using PHY capabilities - allow all LLDP packets from PF to Tx - kbuild: quote OBJCOPY var to avoid a pahole call break the build Previous releases - always broken: - bpf, lockdown, audit: fix buggy SELinux lockdown permission checks - mt76: address the recent FragAttack vulnerabilities not covered by generic fixes - ipv6: fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions - Bluetooth: - fix the erroneous flush_work() order, to avoid double free - use correct lock to prevent UAF of hdev object - nfc: fix NULL ptr dereference in llcp_sock_getname() after failed connect - ieee802154: multiple fixes to error checking and return values - igb: fix XDP with PTP enabled - intel: add correct exception tracing for XDP - tls: fix use-after-free when TLS offload device goes down and back up - ipvs: ignore IP_VS_SVC_F_HASHED flag when adding service - netfilter: nft_ct: skip expectations for confirmed conntrack - mptcp: fix falling back to TCP in presence of out of order packets early in connection lifetime - wireguard: switch from O(n) to a O(1) algorithm for maintaining peers, fixing stalls and a large memory leak in the process Misc: - devlink: correct VIRTUAL port to not have phys_port attributes - Bluetooth: fix VIRTIO_ID_BT assigned number - net: return the correct errno code ENOBUF -> ENOMEM - wireguard: - peer: allocate in kmem_cache saving 25% on peer memory - do not use -O3" * tag 'net-5.13-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (91 commits) cxgb4: avoid link re-train during TC-MQPRIO configuration sch_htb: fix refcount leak in htb_parent_to_leaf_offload wireguard: allowedips: free empty intermediate nodes when removing single node wireguard: allowedips: allocate nodes in kmem_cache wireguard: allowedips: remove nodes in O(1) wireguard: allowedips: initialize list head in selftest wireguard: peer: allocate in kmem_cache wireguard: use synchronize_net rather than synchronize_rcu wireguard: do not use -O3 wireguard: selftests: make sure rp_filter is disabled on vethc wireguard: selftests: remove old conntrack kconfig value virtchnl: Add missing padding to virtchnl_proto_hdrs ice: Allow all LLDP packets from PF to Tx ice: report supported and advertised autoneg using PHY capabilities ice: handle the VF VSI rebuild failure ice: Fix VFR issues for AVF drivers that expect ATQLEN cleared ice: Fix allowing VF to request more/less queues via virtchnl virtio-net: fix for skb_over_panic inside big mode ipv6: Fix KASAN: slab-out-of-bounds Read in fib6_nh_flush_exceptions fib: Return the correct errno code ...
2021-06-04cgroup: Fix kernel-docYang Li
Fix function name in cgroup.c and rstat.c kernel-doc comment to remove these warnings found by clang_w1. kernel/cgroup/cgroup.c:2401: warning: expecting prototype for cgroup_taskset_migrate(). Prototype was for cgroup_migrate_execute() instead. kernel/cgroup/rstat.c:233: warning: expecting prototype for cgroup_rstat_flush_begin(). Prototype was for cgroup_rstat_flush_hold() instead. Reported-by: Abaci Robot <abaci@linux.alibaba.com> Fixes: 'commit e595cd706982 ("cgroup: track migration context in cgroup_mgctx")' Signed-off-by: Yang Li <yang.lee@linux.alibaba.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2021-06-04sched/debug: Remove obsolete init_schedstats()Eric Dumazet
Revert commit 4698f88c06b8 ("sched/debug: Fix 'schedstats=enable' cmdline option"). After commit 6041186a3258 ("init: initialize jump labels before command line option parsing") we can rely on jump label infra being ready for use when setup_schedstats() is called. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Kees Cook <keescook@chromium.org> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Link: https://lkml.kernel.org/r/20210602112108.1709635-1-eric.dumazet@gmail.com
2021-06-03Merge branch 'sched/urgent' into sched/core, to pick up fixesIngo Molnar
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2021-06-03sched/fair: Fix util_est UTIL_AVG_UNCHANGED handlingDietmar Eggemann
The util_est internal UTIL_AVG_UNCHANGED flag which is used to prevent unnecessary util_est updates uses the LSB of util_est.enqueued. It is exposed via _task_util_est() (and task_util_est()). Commit 92a801e5d5b7 ("sched/fair: Mask UTIL_AVG_UNCHANGED usages") mentions that the LSB is lost for util_est resolution but find_energy_efficient_cpu() checks if task_util_est() returns 0 to return prev_cpu early. _task_util_est() returns the max value of util_est.ewma and util_est.enqueued or'ed w/ UTIL_AVG_UNCHANGED. So task_util_est() returning the max of task_util() and _task_util_est() will never return 0 under the default SCHED_FEAT(UTIL_EST, true). To fix this use the MSB of util_est.enqueued instead and keep the flag util_est internal, i.e. don't export it via _task_util_est(). The maximal possible util_avg value for a task is 1024 so the MSB of 'unsigned int util_est.enqueued' isn't used to store a util value. As a caveat the code behind the util_est_se trace point has to filter UTIL_AVG_UNCHANGED to see the real util_est.enqueued value which should be easy to do. This also fixes an issue report by Xuewen Yan that util_est_update() only used UTIL_AVG_UNCHANGED for the subtrahend of the equation: last_enqueued_diff = ue.enqueued - (task_util() | UTIL_AVG_UNCHANGED) Fixes: b89997aa88f0b sched/pelt: Fix task util_est update filtering Signed-off-by: Dietmar Eggemann <dietmar.eggemann@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Xuewen Yan <xuewen.yan@unisoc.com> Reviewed-by: Vincent Donnefort <vincent.donnefort@arm.com> Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lore.kernel.org/r/20210602145808.1562603-1-dietmar.eggemann@arm.com
2021-06-03sched/pelt: Ensure that *_sum is always synced with *_avgVincent Guittot
Rounding in PELT calculation happening when entities are attached/detached of a cfs_rq can result into situations where util/runnable_avg is not null but util/runnable_sum is. This is normally not possible so we need to ensure that util/runnable_sum stays synced with util/runnable_avg. detach_entity_load_avg() is the last place where we don't sync util/runnable_sum with util/runnbale_avg when moving some sched_entities Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210601085832.12626-1-vincent.guittot@linaro.org
2021-06-02bpf, lockdown, audit: Fix buggy SELinux lockdown permission checksDaniel Borkmann
Commit 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") added an implementation of the locked_down LSM hook to SELinux, with the aim to restrict which domains are allowed to perform operations that would breach lockdown. This is indirectly also getting audit subsystem involved to report events. The latter is problematic, as reported by Ondrej and Serhei, since it can bring down the whole system via audit: 1) The audit events that are triggered due to calls to security_locked_down() can OOM kill a machine, see below details [0]. 2) It also seems to be causing a deadlock via avc_has_perm()/slow_avc_audit() when trying to wake up kauditd, for example, when using trace_sched_switch() tracepoint, see details in [1]. Triggering this was not via some hypothetical corner case, but with existing tools like runqlat & runqslower from bcc, for example, which make use of this tracepoint. Rough call sequence goes like: rq_lock(rq) -> -------------------------+ trace_sched_switch() -> | bpf_prog_xyz() -> +-> deadlock selinux_lockdown() -> | audit_log_end() -> | wake_up_interruptible() -> | try_to_wake_up() -> | rq_lock(rq) --------------+ What's worse is that the intention of 59438b46471a to further restrict lockdown settings for specific applications in respect to the global lockdown policy is completely broken for BPF. The SELinux policy rule for the current lockdown check looks something like this: allow <who> <who> : lockdown { <reason> }; However, this doesn't match with the 'current' task where the security_locked_down() is executed, example: httpd does a syscall. There is a tracing program attached to the syscall which triggers a BPF program to run, which ends up doing a bpf_probe_read_kernel{,_str}() helper call. The selinux_lockdown() hook does the permission check against 'current', that is, httpd in this example. httpd has literally zero relation to this tracing program, and it would be nonsensical having to write an SELinux policy rule against httpd to let the tracing helper pass. The policy in this case needs to be against the entity that is installing the BPF program. For example, if bpftrace would generate a histogram of syscall counts by user space application: bpftrace -e 'tracepoint:raw_syscalls:sys_enter { @[comm] = count(); }' bpftrace would then go and generate a BPF program from this internally. One way of doing it [for the sake of the example] could be to call bpf_get_current_task() helper and then access current->comm via one of bpf_probe_read_kernel{,_str}() helpers. So the program itself has nothing to do with httpd or any other random app doing a syscall here. The BPF program _explicitly initiated_ the lockdown check. The allow/deny policy belongs in the context of bpftrace: meaning, you want to grant bpftrace access to use these helpers, but other tracers on the system like my_random_tracer _not_. Therefore fix all three issues at the same time by taking a completely different approach for the security_locked_down() hook, that is, move the check into the program verification phase where we actually retrieve the BPF func proto. This also reliably gets the task (current) that is trying to install the BPF tracing program, e.g. bpftrace/bcc/perf/systemtap/etc, and it also fixes the OOM since we're moving this out of the BPF helper's fast-path which can be called several millions of times per second. The check is then also in line with other security_locked_down() hooks in the system where the enforcement is performed at open/load time, for example, open_kcore() for /proc/kcore access or module_sig_check() for module signatures just to pick few random ones. What's out of scope in the fix as well as in other security_locked_down() hook locations /outside/ of BPF subsystem is that if the lockdown policy changes on the fly there is no retrospective action. This requires a different discussion, potentially complex infrastructure, and it's also not clear whether this can be solved generically. Either way, it is out of scope for a suitable stable fix which this one is targeting. Note that the breakage is specifically on 59438b46471a where it started to rely on 'current' as UAPI behavior, and _not_ earlier infrastructure such as 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode"). [0] https://bugzilla.redhat.com/show_bug.cgi?id=1955585, Jakub Hrozek says: I starting seeing this with F-34. When I run a container that is traced with BPF to record the syscalls it is doing, auditd is flooded with messages like: type=AVC msg=audit(1619784520.593:282387): avc: denied { confidentiality } for pid=476 comm="auditd" lockdown_reason="use of bpf to read kernel RAM" scontext=system_u:system_r:auditd_t:s0 tcontext=system_u:system_r:auditd_t:s0 tclass=lockdown permissive=0 This seems to be leading to auditd running out of space in the backlog buffer and eventually OOMs the machine. [...] auditd running at 99% CPU presumably processing all the messages, eventually I get: Apr 30 12:20:42 fedora kernel: audit: backlog limit exceeded Apr 30 12:20:42 fedora kernel: audit: backlog limit exceeded Apr 30 12:20:42 fedora kernel: audit: audit_backlog=2152579 > audit_backlog_limit=64 Apr 30 12:20:42 fedora kernel: audit: audit_backlog=2152626 > audit_backlog_limit=64 Apr 30 12:20:42 fedora kernel: audit: audit_backlog=2152694 > audit_backlog_limit=64 Apr 30 12:20:42 fedora kernel: audit: audit_lost=6878426 audit_rate_limit=0 audit_backlog_limit=64 Apr 30 12:20:45 fedora kernel: oci-seccomp-bpf invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=-1000 Apr 30 12:20:45 fedora kernel: CPU: 0 PID: 13284 Comm: oci-seccomp-bpf Not tainted 5.11.12-300.fc34.x86_64 #1 Apr 30 12:20:45 fedora kernel: Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-2.fc32 04/01/2014 [...] [1] https://lore.kernel.org/linux-audit/CANYvDQN7H5tVp47fbYcRasv4XF07eUbsDwT_eDCHXJUj43J7jQ@mail.gmail.com/, Serhei Makarov says: Upstream kernel 5.11.0-rc7 and later was found to deadlock during a bpf_probe_read_compat() call within a sched_switch tracepoint. The problem is reproducible with the reg_alloc3 testcase from SystemTap's BPF backend testsuite on x86_64 as well as the runqlat, runqslower tools from bcc on ppc64le. Example stack trace: [...] [ 730.868702] stack backtrace: [ 730.869590] CPU: 1 PID: 701 Comm: in:imjournal Not tainted, 5.12.0-0.rc2.20210309git144c79ef3353.166.fc35.x86_64 #1 [ 730.871605] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 [ 730.873278] Call Trace: [ 730.873770] dump_stack+0x7f/0xa1 [ 730.874433] check_noncircular+0xdf/0x100 [ 730.875232] __lock_acquire+0x1202/0x1e10 [ 730.876031] ? __lock_acquire+0xfc0/0x1e10 [ 730.876844] lock_acquire+0xc2/0x3a0 [ 730.877551] ? __wake_up_common_lock+0x52/0x90 [ 730.878434] ? lock_acquire+0xc2/0x3a0 [ 730.879186] ? lock_is_held_type+0xa7/0x120 [ 730.880044] ? skb_queue_tail+0x1b/0x50 [ 730.880800] _raw_spin_lock_irqsave+0x4d/0x90 [ 730.881656] ? __wake_up_common_lock+0x52/0x90 [ 730.882532] __wake_up_common_lock+0x52/0x90 [ 730.883375] audit_log_end+0x5b/0x100 [ 730.884104] slow_avc_audit+0x69/0x90 [ 730.884836] avc_has_perm+0x8b/0xb0 [ 730.885532] selinux_lockdown+0xa5/0xd0 [ 730.886297] security_locked_down+0x20/0x40 [ 730.887133] bpf_probe_read_compat+0x66/0xd0 [ 730.887983] bpf_prog_250599c5469ac7b5+0x10f/0x820 [ 730.888917] trace_call_bpf+0xe9/0x240 [ 730.889672] perf_trace_run_bpf_submit+0x4d/0xc0 [ 730.890579] perf_trace_sched_switch+0x142/0x180 [ 730.891485] ? __schedule+0x6d8/0xb20 [ 730.892209] __schedule+0x6d8/0xb20 [ 730.892899] schedule+0x5b/0xc0 [ 730.893522] exit_to_user_mode_prepare+0x11d/0x240 [ 730.894457] syscall_exit_to_user_mode+0x27/0x70 [ 730.895361] entry_SYSCALL_64_after_hwframe+0x44/0xae [...] Fixes: 59438b46471a ("security,lockdown,selinux: implement SELinux lockdown") Reported-by: Ondrej Mosnacek <omosnace@redhat.com> Reported-by: Jakub Hrozek <jhrozek@redhat.com> Reported-by: Serhei Makarov <smakarov@redhat.com> Reported-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Tested-by: Jiri Olsa <jolsa@redhat.com> Cc: Paul Moore <paul@paul-moore.com> Cc: James Morris <jamorris@linux.microsoft.com> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Frank Eigler <fche@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: https://lore.kernel.org/bpf/01135120-8bf7-df2e-cff0-1d73f1f841c3@iogearbox.net
2021-06-01sched: Don't defer CPU pick to migration_cpu_stop()Valentin Schneider
Will reported that the 'XXX __migrate_task() can fail' in migration_cpu_stop() can happen, and it *is* sort of a big deal. Looking at it some more, one will note there is a glaring hole in the deferred CPU selection: (w/ CONFIG_CPUSET=n, so that the affinity mask passed via taskset doesn't get AND'd with cpu_online_mask) $ taskset -pc 0-2 $PID # offline CPUs 3-4 $ taskset -pc 3-5 $PID `\ $PID may stay on 0-2 due to the cpumask_any_distribute() picking an offline CPU and __migrate_task() refusing to do anything due to cpu_is_allowed(). set_cpus_allowed_ptr() goes to some length to pick a dest_cpu that matches the right constraints vs affinity and the online/active state of the CPUs. Reuse that instead of discarding it in the affine_move_task() case. Fixes: 6d337eab041d ("sched: Fix migrate_disable() vs set_cpus_allowed_ptr()") Reported-by: Will Deacon <will@kernel.org> Signed-off-by: Valentin Schneider <valentin.schneider@arm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Link: https://lkml.kernel.org/r/20210526205751.842360-2-valentin.schneider@arm.com
2021-06-01sched/fair: Fix ascii art by relpacing tabsOdin Ugedal
When using something other than 8 spaces per tab, this ascii art makes not sense, and the reader might end up wondering what this advanced equation "is". Signed-off-by: Odin Ugedal <odin@uged.al> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: Vincent Guittot <vincent.guittot@linaro.org> Link: https://lkml.kernel.org/r/20210518125202.78658-4-odin@uged.al
2021-06-01sched,init: Fix DEBUG_PREEMPT vs early bootPeter Zijlstra
Extend 8fb12156b8db ("init: Pin init task to the boot CPU, initially") to cover the new PF_NO_SETAFFINITY requirement. While there, move wait_for_completion(&kthreadd_done) into kernel_init() to make it absolutely clear it is the very first thing done by the init thread. Fixes: 570a752b7a9b ("lib/smp_processor_id: Use is_percpu_thread() instead of nr_cpus_allowed") Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Valentin Schneider <valentin.schneider@arm.com> Tested-by: Borislav Petkov <bp@alien8.de> Link: https://lkml.kernel.org/r/YLS4mbKUrA3Gnb4t@hirez.programming.kicks-ass.net