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commit 9a066357184485784f782719093ff804d05b85db upstream.
The 'head' and 'tail' commands can take a file path directly.
So, you do not need to run 'cat'.
cat kernel/kheaders.md5 | head -1
... is equivalent to:
head -1 kernel/kheaders.md5
and the latter saves forking one process.
While I was here, I replaced 'head -1' with 'head -n 1'.
I also replaced '==' with '=' since we do not have a good reason to
use the bashism.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 784a0830377d0761834e385975bc46861fea9fa0 upstream.
Most of the CPU mask operations behave the same way, but for_each_cpu() and
it's variants ignore the cpumask argument and claim that CPU0 is always in
the mask. This is historical, inconsistent and annoying behaviour.
The matrix allocator uses for_each_cpu() and can be called on UP with an
empty cpumask. The calling code does not expect that this succeeds but
until commit e027fffff799 ("x86/irq: Unbreak interrupt affinity setting")
this went unnoticed. That commit added a WARN_ON() to catch cases which
move an interrupt from one vector to another on the same CPU. The warning
triggers on UP.
Add a check for the cpumask being empty to prevent this.
Fixes: 2f75d9e1c905 ("genirq: Implement bitmap matrix allocator")
Reported-by: kernel test robot <rong.a.chen@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit e65855a52b479f98674998cb23b21ef5a8144b04 ]
The following splat was caught when setting uclamp value of a task:
BUG: sleeping function called from invalid context at ./include/linux/percpu-rwsem.h:49
cpus_read_lock+0x68/0x130
static_key_enable+0x1c/0x38
__sched_setscheduler+0x900/0xad8
Fix by ensuring we enable the key outside of the critical section in
__sched_setscheduler()
Fixes: 46609ce22703 ("sched/uclamp: Protect uclamp fast path code with static key")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200716110347.19553-4-qais.yousef@arm.com
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 46609ce227039fd192e0ecc7d940bed587fd2c78 ]
There is a report that when uclamp is enabled, a netperf UDP test
regresses compared to a kernel compiled without uclamp.
https://lore.kernel.org/lkml/20200529100806.GA3070@suse.de/
While investigating the root cause, there were no sign that the uclamp
code is doing anything particularly expensive but could suffer from bad
cache behavior under certain circumstances that are yet to be
understood.
https://lore.kernel.org/lkml/20200616110824.dgkkbyapn3io6wik@e107158-lin/
To reduce the pressure on the fast path anyway, add a static key that is
by default will skip executing uclamp logic in the
enqueue/dequeue_task() fast path until it's needed.
As soon as the user start using util clamp by:
1. Changing uclamp value of a task with sched_setattr()
2. Modifying the default sysctl_sched_util_clamp_{min, max}
3. Modifying the default cpu.uclamp.{min, max} value in cgroup
We flip the static key now that the user has opted to use util clamp.
Effectively re-introducing uclamp logic in the enqueue/dequeue_task()
fast path. It stays on from that point forward until the next reboot.
This should help minimize the effect of util clamp on workloads that
don't need it but still allow distros to ship their kernels with uclamp
compiled in by default.
SCHED_WARN_ON() in uclamp_rq_dec_id() was removed since now we can end
up with unbalanced call to uclamp_rq_dec_id() if we flip the key while
a task is running in the rq. Since we know it is harmless we just
quietly return if we attempt a uclamp_rq_dec_id() when
rq->uclamp[].bucket[].tasks is 0.
In schedutil, we introduce a new uclamp_is_enabled() helper which takes
the static key into account to ensure RT boosting behavior is retained.
The following results demonstrates how this helps on 2 Sockets Xeon E5
2x10-Cores system.
nouclamp uclamp uclamp-static-key
Hmean send-64 162.43 ( 0.00%) 157.84 * -2.82%* 163.39 * 0.59%*
Hmean send-128 324.71 ( 0.00%) 314.78 * -3.06%* 326.18 * 0.45%*
Hmean send-256 641.55 ( 0.00%) 628.67 * -2.01%* 648.12 * 1.02%*
Hmean send-1024 2525.28 ( 0.00%) 2448.26 * -3.05%* 2543.73 * 0.73%*
Hmean send-2048 4836.14 ( 0.00%) 4712.08 * -2.57%* 4867.69 * 0.65%*
Hmean send-3312 7540.83 ( 0.00%) 7425.45 * -1.53%* 7621.06 * 1.06%*
Hmean send-4096 9124.53 ( 0.00%) 8948.82 * -1.93%* 9276.25 * 1.66%*
Hmean send-8192 15589.67 ( 0.00%) 15486.35 * -0.66%* 15819.98 * 1.48%*
Hmean send-16384 26386.47 ( 0.00%) 25752.25 * -2.40%* 26773.74 * 1.47%*
The perf diff between nouclamp and uclamp-static-key when uclamp is
disabled in the fast path:
8.73% -1.55% [kernel.kallsyms] [k] try_to_wake_up
0.07% +0.04% [kernel.kallsyms] [k] deactivate_task
0.13% -0.02% [kernel.kallsyms] [k] activate_task
The diff between nouclamp and uclamp-static-key when uclamp is enabled
in the fast path:
8.73% -0.72% [kernel.kallsyms] [k] try_to_wake_up
0.13% +0.39% [kernel.kallsyms] [k] activate_task
0.07% +0.38% [kernel.kallsyms] [k] deactivate_task
Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting")
Reported-by: Mel Gorman <mgorman@suse.de>
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-3-qais.yousef@arm.com
[ Fix minor conflict with kernel/sched.h because of function renamed
later ]
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit a7ef9b28aa8d72a1656fa6f0a01bbd1493886317 ]
Though the number of lock-acquisitions is tracked as unsigned long, this
is passed as the divisor to div_s64() which interprets it as a s32,
giving nonsense values with more than 2 billion acquisitons. E.g.
acquisitions holdtime-min holdtime-max holdtime-total holdtime-avg
-------------------------------------------------------------------------
2350439395 0.07 353.38 649647067.36 0.-32
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200725185110.11588-1-chris@chris-wilson.co.uk
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit b431ef837e3374da0db8ff6683170359aaa0859c ]
We make an assumption that a debugfs directory exists, but since
this can fail ensure it exists before allowing blktrace setup to
complete. Otherwise we end up stuffing blktrace files on the debugfs
root directory. In the worst case scenario this *in theory* can create
an eventual panic *iff* in the future a similarly named file is created
prior on the debugfs root directory. This theoretical crash can happen
due to a recursive removal followed by a specific dentry removal.
This doesn't fix any known crash, however I have seen the files
go into the main debugfs root directory in cases where the debugfs
directory was not created due to other internal bugs with blktrace
now fixed.
blktrace is also completely useless without this directory, so
this ensures to userspace we only setup blktrace if the kernel
can stuff files where they are supposed to go into.
debugfs directory creations typically aren't checked for, and we have
maintainers doing sweep removals of these checks, but since we need this
check to ensure proper userspace blktrace functionality we make sure
to annotate the justification for the check.
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 26c7295be0c5e6da3fa45970e9748be983175b1b upstream.
when we create a kthread with ktrhead_create_on_cpu(),the child thread
entry is ktread.c:ktrhead() which will be preempted by the parent after
call complete(done) while schedule() is not called yet,then the parent
will call wait_task_inactive(child) but the child is still on the runqueue,
so the parent will schedule_hrtimeout() for 1 jiffy,it will waste a lot of
time,especially on startup.
parent child
ktrhead_create_on_cpu()
wait_fo_completion(&done) -----> ktread.c:ktrhead()
|----- complete(done);--wakeup and preempted by parent
kthread_bind() <------------| |-> schedule();--dequeue here
wait_task_inactive(child) |
schedule_hrtimeout(1 jiffy) -|
So we hope the child just wakeup parent but not preempted by parent, and the
child is going to call schedule() soon,then the parent will not call
schedule_hrtimeout(1 jiffy) as the child is already dequeue.
The same issue for ktrhead_park()&&kthread_parkme().
This patch can save 120ms on rk312x startup with CONFIG_HZ=300.
Signed-off-by: Liang Chen <cl@rock-chips.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/20200306070133.18335-2-cl@rock-chips.com
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit c17c3dc9d08b9aad9a55a1e53f205187972f448e upstream.
syzbot crashed on the VM_BUG_ON_PAGE(PageTail) in munlock_vma_page(), when
called from uprobes __replace_page(). Which of many ways to fix it?
Settled on not calling when PageCompound (since Head and Tail are equals
in this context, PageCompound the usual check in uprobes.c, and the prior
use of FOLL_SPLIT_PMD will have cleared PageMlocked already).
Fixes: 5a52c9df62b4 ("uprobe: use FOLL_SPLIT_PMD instead of FOLL_SPLIT")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Oleg Nesterov <oleg@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: <stable@vger.kernel.org> [5.4+]
Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008161338360.20413@eggly.anvils
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 71e843295c680898959b22dc877ae3839cc22470 upstream.
kmemleak report memory leak as follows:
unreferenced object 0x607ee4e5f948 (size 8):
comm "syz-executor.1", pid 2098, jiffies 4295031601 (age 288.468s)
hex dump (first 8 bytes):
00 00 00 00 00 00 00 00 ........
backtrace:
relay_open kernel/relay.c:583 [inline]
relay_open+0xb6/0x970 kernel/relay.c:563
do_blk_trace_setup+0x4a8/0xb20 kernel/trace/blktrace.c:557
__blk_trace_setup+0xb6/0x150 kernel/trace/blktrace.c:597
blk_trace_ioctl+0x146/0x280 kernel/trace/blktrace.c:738
blkdev_ioctl+0xb2/0x6a0 block/ioctl.c:613
block_ioctl+0xe5/0x120 fs/block_dev.c:1871
vfs_ioctl fs/ioctl.c:48 [inline]
__do_sys_ioctl fs/ioctl.c:753 [inline]
__se_sys_ioctl fs/ioctl.c:739 [inline]
__x64_sys_ioctl+0x170/0x1ce fs/ioctl.c:739
do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
entry_SYSCALL_64_after_hwframe+0x44/0xa9
'chan->buf' is malloced in relay_open() by alloc_percpu() but not free
while destroy the relay channel. Fix it by adding free_percpu() before
return from relay_destroy_channel().
Fixes: 017c59c042d0 ("relay: Use per CPU constructs for the relay channel buffer pointers")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: David Rientjes <rientjes@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: Daniel Axtens <dja@axtens.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Akash Goel <akash.goel@intel.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200817122826.48518-1-weiyongjun1@huawei.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 11990a5bd7e558e9203c1070fc52fb6f0488e75b upstream.
The only-root-readable /sys/module/$module/sections/$section files
did not truncate their output to the available buffer size. While most
paths into the kernfs read handlers end up using PAGE_SIZE buffers,
it's possible to get there through other paths (e.g. splice, sendfile).
Actually limit the output to the "count" passed into the read function,
and report it back correctly. *sigh*
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/20200805002015.GE23458@shao2-debian
Fixes: ed66f991bb19 ("module: Refactor section attr into bin attribute")
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 7ef282e05132d56b6f6b71e3873f317664bea78b upstream.
If a process has the trace_pipe open on a trace_array, the current tracer
for that trace array should not be changed. This was original enforced by a
global lock, but when instances were introduced, it was moved to the
current_trace. But this structure is shared by all instances, and a
trace_pipe is for a single instance. There's no reason that a process that
has trace_pipe open on one instance should prevent another instance from
changing its current tracer. Move the reference counter to the trace_array
instead.
This is marked as "Fixes" but is more of a clean up than a true fix.
Backport if you want, but its not critical.
Fixes: cf6ab6d9143b1 ("tracing: Add ref count to tracer for when they are being read by pipe")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
[Resolved conflict in __remove_instance()]
Signed-off-by: dann frazier <dann.frazier@canonical.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit afcab636657421f7ebfa0783a91f90256bba0091 upstream.
On exit, if a process is preempted after the trace_sched_process_exit()
tracepoint but before the process is done exiting, then when it gets
scheduled in, the function tracers will not filter it properly against the
function tracing pid filters.
That is because the function tracing pid filters hooks to the
sched_process_exit() tracepoint to remove the exiting task's pid from the
filter list. Because the filtering happens at the sched_switch tracepoint,
when the exiting task schedules back in to finish up the exit, it will no
longer be in the function pid filtering tables.
This was noticeable in the notrace self tests on a preemptable kernel, as
the tests would fail as it exits and preempted after being taken off the
notrace filter table and on scheduling back in it would not be in the
notrace list, and then the ending of the exit function would trace. The test
detected this and would fail.
Cc: stable@vger.kernel.org
Cc: Namhyung Kim <namhyung@kernel.org>
Fixes: 1e10486ffee0a ("ftrace: Add 'function-fork' trace option")
Fixes: c37775d57830a ("tracing: Add infrastructure to allow set_event_pid to follow children"
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 96b4833b6827a62c295b149213c68b559514c929 upstream.
In calculation of the cpu mask for the hwlat kernel thread, the wrong
cpu mask is used instead of the tracing_cpumask, this causes the
tracing/tracing_cpumask useless for hwlat tracer. Fixes it.
Link: https://lkml.kernel.org/r/20200730082318.42584-2-haokexin@gmail.com
Cc: Ingo Molnar <mingo@redhat.com>
Cc: stable@vger.kernel.org
Fixes: 0330f7aa8ee6 ("tracing: Have hwlat trace migrate across tracing_cpumask CPUs")
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 0cb2f1372baa60af8456388a574af6133edd7d80 upstream.
We found a case of kernel panic on our server. The stack trace is as
follows(omit some irrelevant information):
BUG: kernel NULL pointer dereference, address: 0000000000000080
RIP: 0010:kprobe_ftrace_handler+0x5e/0xe0
RSP: 0018:ffffb512c6550998 EFLAGS: 00010282
RAX: 0000000000000000 RBX: ffff8e9d16eea018 RCX: 0000000000000000
RDX: ffffffffbe1179c0 RSI: ffffffffc0535564 RDI: ffffffffc0534ec0
RBP: ffffffffc0534ec1 R08: ffff8e9d1bbb0f00 R09: 0000000000000004
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8e9d1f797060 R14: 000000000000bacc R15: ffff8e9ce13eca00
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000080 CR3: 00000008453d0005 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
ftrace_ops_assist_func+0x56/0xe0
ftrace_call+0x5/0x34
tcpa_statistic_send+0x5/0x130 [ttcp_engine]
The tcpa_statistic_send is the function being kprobed. After analysis,
the root cause is that the fourth parameter regs of kprobe_ftrace_handler
is NULL. Why regs is NULL? We use the crash tool to analyze the kdump.
crash> dis tcpa_statistic_send -r
<tcpa_statistic_send>: callq 0xffffffffbd8018c0 <ftrace_caller>
The tcpa_statistic_send calls ftrace_caller instead of ftrace_regs_caller.
So it is reasonable that the fourth parameter regs of kprobe_ftrace_handler
is NULL. In theory, we should call the ftrace_regs_caller instead of the
ftrace_caller. After in-depth analysis, we found a reproducible path.
Writing a simple kernel module which starts a periodic timer. The
timer's handler is named 'kprobe_test_timer_handler'. The module
name is kprobe_test.ko.
1) insmod kprobe_test.ko
2) bpftrace -e 'kretprobe:kprobe_test_timer_handler {}'
3) echo 0 > /proc/sys/kernel/ftrace_enabled
4) rmmod kprobe_test
5) stop step 2) kprobe
6) insmod kprobe_test.ko
7) bpftrace -e 'kretprobe:kprobe_test_timer_handler {}'
We mark the kprobe as GONE but not disarm the kprobe in the step 4).
The step 5) also do not disarm the kprobe when unregister kprobe. So
we do not remove the ip from the filter. In this case, when the module
loads again in the step 6), we will replace the code to ftrace_caller
via the ftrace_module_enable(). When we register kprobe again, we will
not replace ftrace_caller to ftrace_regs_caller because the ftrace is
disabled in the step 3). So the step 7) will trigger kernel panic. Fix
this problem by disarming the kprobe when the module is going away.
Link: https://lkml.kernel.org/r/20200728064536.24405-1-songmuchun@bytedance.com
Cc: stable@vger.kernel.org
Fixes: ae6aa16fdc16 ("kprobes: introduce ftrace based optimization")
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 8a224ffb3f52b0027f6b7279854c71a31c48fc97 upstream.
When module loaded and enabled, we will use __ftrace_replace_code
for module if any ftrace_ops referenced it found. But we will get
wrong ftrace_addr for module rec in ftrace_get_addr_new, because
rec->flags has not been setup correctly. It can cause the callback
function of a ftrace_ops has FTRACE_OPS_FL_SAVE_REGS to be called
with pt_regs set to NULL.
So setup correct FTRACE_FL_REGS flags for rec when we call
referenced_filters to find ftrace_ops references it.
Link: https://lkml.kernel.org/r/20200728180554.65203-1-zhouchengming@bytedance.com
Cc: stable@vger.kernel.org
Fixes: 8c4f3c3fa9681 ("ftrace: Check module functions being traced on reload")
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e27b1636e9337d1a1d174b191e53d0f86421a822 upstream.
rearm_wake_irq() does not unlock the irq descriptor if the interrupt
is not suspended or if wakeup is not enabled on it.
Restucture the exit conditions so the unlock is always ensured.
Fixes: 3a79bc63d9075 ("PCI: irq: Introduce rearm_wake_irq()")
Signed-off-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200811180001.80203-1-linux@roeck-us.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f0c7baca180046824e07fc5f1326e83a8fd150c7 upstream.
John reported that on a RK3288 system the perf per CPU interrupts are all
affine to CPU0 and provided the analysis:
"It looks like what happens is that because the interrupts are not per-CPU
in the hardware, armpmu_request_irq() calls irq_force_affinity() while
the interrupt is deactivated and then request_irq() with IRQF_PERCPU |
IRQF_NOBALANCING.
Now when irq_startup() runs with IRQ_STARTUP_NORMAL, it calls
irq_setup_affinity() which returns early because IRQF_PERCPU and
IRQF_NOBALANCING are set, leaving the interrupt on its original CPU."
This was broken by the recent commit which blocked interrupt affinity
setting in hardware before activation of the interrupt. While this works in
general, it does not work for this particular case. As contrary to the
initial analysis not all interrupt chip drivers implement an activate
callback, the safe cure is to make the deferred interrupt affinity setting
at activation time opt-in.
Implement the necessary core logic and make the two irqchip implementations
for which this is required opt-in. In hindsight this would have been the
right thing to do, but ...
Fixes: baedb87d1b53 ("genirq/affinity: Handle affinity setting on inactive interrupts correctly")
Reported-by: John Keeping <john@metanate.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Marc Zyngier <maz@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/87blk4tzgm.fsf@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 47e33c05f9f07cac3de833e531bcac9ae052c7ca ]
When SECCOMP_IOCTL_NOTIF_ID_VALID was first introduced it had the wrong
direction flag set. While this isn't a big deal as nothing currently
enforces these bits in the kernel, it should be defined correctly. Fix
the define and provide support for the old command until it is no longer
needed for backward compatibility.
Fixes: 6a21cc50f0c7 ("seccomp: add a return code to trap to userspace")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d81ae8aac85ca2e307d273f6dc7863a721bf054e ]
struct uclamp_rq was zeroed out entirely in assumption that in the first
call to uclamp_rq_inc() they'd be initialized correctly in accordance to
default settings.
But when next patch introduces a static key to skip
uclamp_rq_{inc,dec}() until userspace opts in to use uclamp, schedutil
will fail to perform any frequency changes because the
rq->uclamp[UCLAMP_MAX].value is zeroed at init and stays as such. Which
means all rqs are capped to 0 by default.
Fix it by making sure we do proper initialization at init without
relying on uclamp_rq_inc() doing it later.
Fixes: 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting")
Signed-off-by: Qais Yousef <qais.yousef@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Lukasz Luba <lukasz.luba@arm.com>
Link: https://lkml.kernel.org/r/20200630112123.12076-2-qais.yousef@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit bad8e64fb19d3a0de5e564d9a7271c31bd684369 ]
On commit 6ac93117ab00 ("blktrace: use existing disk debugfs directory")
merged on v4.12 Omar fixed the original blktrace code for request-based
drivers (multiqueue). This however left in place a possible crash, if you
happen to abuse blktrace while racing to remove / add a device.
We used to use asynchronous removal of the request_queue, and with that
the issue was easier to reproduce. Now that we have reverted to
synchronous removal of the request_queue, the issue is still possible to
reproduce, its however just a bit more difficult.
We essentially run two instances of break-blktrace which add/remove
a loop device, and setup a blktrace and just never tear the blktrace
down. We do this twice in parallel. This is easily reproduced with the
script run_0004.sh from break-blktrace [0].
We can end up with two types of panics each reflecting where we
race, one a failed blktrace setup:
[ 252.426751] debugfs: Directory 'loop0' with parent 'block' already present!
[ 252.432265] BUG: kernel NULL pointer dereference, address: 00000000000000a0
[ 252.436592] #PF: supervisor write access in kernel mode
[ 252.439822] #PF: error_code(0x0002) - not-present page
[ 252.442967] PGD 0 P4D 0
[ 252.444656] Oops: 0002 [#1] SMP NOPTI
[ 252.446972] CPU: 10 PID: 1153 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164
[ 252.452673] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
[ 252.456343] RIP: 0010:down_write+0x15/0x40
[ 252.458146] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc
cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00
00 00 <f0> 48 0f b1 55 00 75 0f 48 8b 04 25 c0 8b 01 00 48 89
45 08 5d
[ 252.463638] RSP: 0018:ffffa626415abcc8 EFLAGS: 00010246
[ 252.464950] RAX: 0000000000000000 RBX: ffff958c25f0f5c0 RCX: ffffff8100000000
[ 252.466727] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0
[ 252.468482] RBP: 00000000000000a0 R08: 0000000000000000 R09: 0000000000000001
[ 252.470014] R10: 0000000000000000 R11: ffff958d1f9227ff R12: 0000000000000000
[ 252.471473] R13: ffff958c25ea5380 R14: ffffffff8cce15f1 R15: 00000000000000a0
[ 252.473346] FS: 00007f2e69dee540(0000) GS:ffff958c2fc80000(0000) knlGS:0000000000000000
[ 252.475225] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 252.476267] CR2: 00000000000000a0 CR3: 0000000427d10004 CR4: 0000000000360ee0
[ 252.477526] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 252.478776] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 252.479866] Call Trace:
[ 252.480322] simple_recursive_removal+0x4e/0x2e0
[ 252.481078] ? debugfs_remove+0x60/0x60
[ 252.481725] ? relay_destroy_buf+0x77/0xb0
[ 252.482662] debugfs_remove+0x40/0x60
[ 252.483518] blk_remove_buf_file_callback+0x5/0x10
[ 252.484328] relay_close_buf+0x2e/0x60
[ 252.484930] relay_open+0x1ce/0x2c0
[ 252.485520] do_blk_trace_setup+0x14f/0x2b0
[ 252.486187] __blk_trace_setup+0x54/0xb0
[ 252.486803] blk_trace_ioctl+0x90/0x140
[ 252.487423] ? do_sys_openat2+0x1ab/0x2d0
[ 252.488053] blkdev_ioctl+0x4d/0x260
[ 252.488636] block_ioctl+0x39/0x40
[ 252.489139] ksys_ioctl+0x87/0xc0
[ 252.489675] __x64_sys_ioctl+0x16/0x20
[ 252.490380] do_syscall_64+0x52/0x180
[ 252.491032] entry_SYSCALL_64_after_hwframe+0x44/0xa9
And the other on the device removal:
[ 128.528940] debugfs: Directory 'loop0' with parent 'block' already present!
[ 128.615325] BUG: kernel NULL pointer dereference, address: 00000000000000a0
[ 128.619537] #PF: supervisor write access in kernel mode
[ 128.622700] #PF: error_code(0x0002) - not-present page
[ 128.625842] PGD 0 P4D 0
[ 128.627585] Oops: 0002 [#1] SMP NOPTI
[ 128.629871] CPU: 12 PID: 544 Comm: break-blktrace Tainted: G E 5.7.0-rc2-next-20200420+ #164
[ 128.635595] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1 04/01/2014
[ 128.640471] RIP: 0010:down_write+0x15/0x40
[ 128.643041] Code: eb ca e8 ae 22 8d ff cc cc cc cc cc cc cc cc cc cc cc cc
cc cc 0f 1f 44 00 00 55 48 89 fd e8 52 db ff ff 31 c0 ba 01 00
00 00 <f0> 48 0f b1 55 00 75 0f 65 48 8b 04 25 c0 8b 01 00 48 89
45 08 5d
[ 128.650180] RSP: 0018:ffffa9c3c05ebd78 EFLAGS: 00010246
[ 128.651820] RAX: 0000000000000000 RBX: ffff8ae9a6370240 RCX: ffffff8100000000
[ 128.653942] RDX: 0000000000000001 RSI: ffffff8100000000 RDI: 00000000000000a0
[ 128.655720] RBP: 00000000000000a0 R08: 0000000000000002 R09: ffff8ae9afd2d3d0
[ 128.657400] R10: 0000000000000056 R11: 0000000000000000 R12: 0000000000000000
[ 128.659099] R13: 0000000000000000 R14: 0000000000000003 R15: 00000000000000a0
[ 128.660500] FS: 00007febfd995540(0000) GS:ffff8ae9afd00000(0000) knlGS:0000000000000000
[ 128.662204] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 128.663426] CR2: 00000000000000a0 CR3: 0000000420042003 CR4: 0000000000360ee0
[ 128.664776] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 128.666022] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 128.667282] Call Trace:
[ 128.667801] simple_recursive_removal+0x4e/0x2e0
[ 128.668663] ? debugfs_remove+0x60/0x60
[ 128.669368] debugfs_remove+0x40/0x60
[ 128.669985] blk_trace_free+0xd/0x50
[ 128.670593] __blk_trace_remove+0x27/0x40
[ 128.671274] blk_trace_shutdown+0x30/0x40
[ 128.671935] blk_release_queue+0x95/0xf0
[ 128.672589] kobject_put+0xa5/0x1b0
[ 128.673188] disk_release+0xa2/0xc0
[ 128.673786] device_release+0x28/0x80
[ 128.674376] kobject_put+0xa5/0x1b0
[ 128.674915] loop_remove+0x39/0x50 [loop]
[ 128.675511] loop_control_ioctl+0x113/0x130 [loop]
[ 128.676199] ksys_ioctl+0x87/0xc0
[ 128.676708] __x64_sys_ioctl+0x16/0x20
[ 128.677274] do_syscall_64+0x52/0x180
[ 128.677823] entry_SYSCALL_64_after_hwframe+0x44/0xa9
The common theme here is:
debugfs: Directory 'loop0' with parent 'block' already present
This crash happens because of how blktrace uses the debugfs directory
where it places its files. Upon init we always create the same directory
which would be needed by blktrace but we only do this for make_request
drivers (multiqueue) block drivers. When you race a removal of these
devices with a blktrace setup you end up in a situation where the
make_request recursive debugfs removal will sweep away the blktrace
files and then later blktrace will also try to remove individual
dentries which are already NULL. The inverse is also possible and hence
the two types of use after frees.
We don't create the block debugfs directory on init for these types of
block devices:
* request-based block driver block devices
* every possible partition
* scsi-generic
And so, this race should in theory only be possible with make_request
drivers.
We can fix the UAF by simply re-using the debugfs directory for
make_request drivers (multiqueue) and only creating the ephemeral
directory for the other type of block devices. The new clarifications
on relying on the q->blk_trace_mutex *and* also checking for q->blk_trace
*prior* to processing a blktrace ensures the debugfs directories are
only created if no possible directory name clashes are possible.
This goes tested with:
o nvme partitions
o ISCSI with tgt, and blktracing against scsi-generic with:
o block
o tape
o cdrom
o media changer
o blktests
This patch is part of the work which disputes the severity of
CVE-2019-19770 which shows this issue is not a core debugfs issue, but
a misuse of debugfs within blktace.
Fixes: 6ac93117ab00 ("blktrace: use existing disk debugfs directory")
Reported-by: syzbot+603294af2d01acfdd6da@syzkaller.appspotmail.com
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Omar Sandoval <osandov@fb.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Nicolai Stange <nstange@suse.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: yu kuai <yukuai3@huawei.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 9b1b234bb86bcdcdb142e900d39b599185465dbb ]
During sched domain init, we check whether non-topological SD_flags are
returned by tl->sd_flags(), if found, fire a waning and correct the
violation, but the code failed to correct the violation. Correct this.
Fixes: 143e1e28cb40 ("sched: Rework sched_domain topology definition")
Signed-off-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lkml.kernel.org/r/20200609150936.GA13060@iZj6chx1xj0e0buvshuecpZ
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 3ea2f097b17e13a8280f1f9386c331b326a3dbef ]
With commit:
'b7031a02ec75 ("sched/fair: Add NOHZ_STATS_KICK")'
rebalance_domains of the local cfs_rq happens before others idle cpus have
updated nohz.next_balance and its value is overwritten.
Move the update of nohz.next_balance for other idles cpus before balancing
and updating the next_balance of local cfs_rq.
Also, the nohz.next_balance is now updated only if all idle cpus got a
chance to rebalance their domains and the idle balance has not been aborted
because of new activities on the CPU. In case of need_resched, the idle
load balance will be kick the next jiffie in order to address remaining
ilb.
Fixes: b7031a02ec75 ("sched/fair: Add NOHZ_STATS_KICK")
Reported-by: Peng Liu <iwtbavbm@gmail.com>
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Acked-by: Mel Gorman <mgorman@suse.de>
Link: https://lkml.kernel.org/r/20200609123748.18636-1-vincent.guittot@linaro.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 90c91dfb86d0ff545bd329d3ddd72c147e2ae198 upstream.
Kan and Andi reported that we fail to kill rotation when the flexible
events go empty, but the context does not. XXX moar
Fixes: fd7d55172d1e ("perf/cgroups: Don't rotate events for cgroups unnecessarily")
Reported-by: Andi Kleen <ak@linux.intel.com>
Reported-by: Kan Liang <kan.liang@linux.intel.com>
Tested-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200305123851.GX2596@hirez.programming.kicks-ass.net
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit bb0de3131f4c60a9bf976681e0fe4d1e55c7a821 upstream.
The sockmap code currently ignores the value of attach_bpf_fd when
detaching a program. This is contrary to the usual behaviour of
checking that attach_bpf_fd represents the currently attached
program.
Ensure that attach_bpf_fd is indeed the currently attached
program. It turns out that all sockmap selftests already do this,
which indicates that this is unlikely to cause breakage.
Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Lorenz Bauer <lmb@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200629095630.7933-5-lmb@cloudflare.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit f227e3ec3b5cad859ad15666874405e8c1bbc1d4 upstream.
This modifies the first 32 bits out of the 128 bits of a random CPU's
net_rand_state on interrupt or CPU activity to complicate remote
observations that could lead to guessing the network RNG's internal
state.
Note that depending on some network devices' interrupt rate moderation
or binding, this re-seeding might happen on every packet or even almost
never.
In addition, with NOHZ some CPUs might not even get timer interrupts,
leaving their local state rarely updated, while they are running
networked processes making use of the random state. For this reason, we
also perform this update in update_process_times() in order to at least
update the state when there is user or system activity, since it's the
only case we care about.
Reported-by: Amit Klein <aksecurity@gmail.com>
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "Jason A. Donenfeld" <Jason@zx2c4.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 1d4e1eab456e1ee92a94987499b211db05f900ea ]
Fix HASH_OF_MAPS bug of not putting inner map pointer on bpf_map_elem_update()
operation. This is due to per-cpu extra_elems optimization, which bypassed
free_htab_elem() logic doing proper clean ups. Make sure that inner map is put
properly in optimized case as well.
Fixes: 8c290e60fa2a ("bpf: fix hashmap extra_elems logic")
Signed-off-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20200729040913.2815687-1-andriin@fb.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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GDB regression
commit fe5ed7ab99c656bd2f5b79b49df0e9ebf2cead8a upstream.
If a tracee is uprobed and it hits int3 inserted by debugger, handle_swbp()
does send_sig(SIGTRAP, current, 0) which means si_code == SI_USER. This used
to work when this code was written, but then GDB started to validate si_code
and now it simply can't use breakpoints if the tracee has an active uprobe:
# cat test.c
void unused_func(void)
{
}
int main(void)
{
return 0;
}
# gcc -g test.c -o test
# perf probe -x ./test -a unused_func
# perf record -e probe_test:unused_func gdb ./test -ex run
GNU gdb (GDB) 10.0.50.20200714-git
...
Program received signal SIGTRAP, Trace/breakpoint trap.
0x00007ffff7ddf909 in dl_main () from /lib64/ld-linux-x86-64.so.2
(gdb)
The tracee hits the internal breakpoint inserted by GDB to monitor shared
library events but GDB misinterprets this SIGTRAP and reports a signal.
Change handle_swbp() to use force_sig(SIGTRAP), this matches do_int3_user()
and fixes the problem.
This is the minimal fix for -stable, arch/x86/kernel/uprobes.c is equally
wrong; it should use send_sigtrap(TRAP_TRACE) instead of send_sig(SIGTRAP),
but this doesn't confuse GDB and needs another x86-specific patch.
Reported-by: Aaron Merey <amerey@redhat.com>
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200723154420.GA32043@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit baedb87d1b53532f81b4bd0387f83b05d4f7eb9a upstream.
Setting interrupt affinity on inactive interrupts is inconsistent when
hierarchical irq domains are enabled. The core code should just store the
affinity and not call into the irq chip driver for inactive interrupts
because the chip drivers may not be in a state to handle such requests.
X86 has a hacky workaround for that but all other irq chips have not which
causes problems e.g. on GIC V3 ITS.
Instead of adding more ugly hacks all over the place, solve the problem in
the core code. If the affinity is set on an inactive interrupt then:
- Store it in the irq descriptors affinity mask
- Update the effective affinity to reflect that so user space has
a consistent view
- Don't call into the irq chip driver
This is the core equivalent of the X86 workaround and works correctly
because the affinity setting is established in the irq chip when the
interrupt is activated later on.
Note, that this is only effective when hierarchical irq domains are enabled
by the architecture. Doing it unconditionally would break legacy irq chip
implementations.
For hierarchial irq domains this works correctly as none of the drivers can
have a dependency on affinity setting in inactive state by design.
Remove the X86 workaround as it is not longer required.
Fixes: 02edee152d6e ("x86/apic/vector: Ignore set_affinity call for inactive interrupts")
Reported-by: Ali Saidi <alisaidi@amazon.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Ali Saidi <alisaidi@amazon.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20200529015501.15771-1-alisaidi@amazon.com
Link: https://lkml.kernel.org/r/877dv2rv25.fsf@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 01cfcde9c26d8555f0e6e9aea9d6049f87683998 upstream.
task_h_load() can return 0 in some situations like running stress-ng
mmapfork, which forks thousands of threads, in a sched group on a 224 cores
system. The load balance doesn't handle this correctly because
env->imbalance never decreases and it will stop pulling tasks only after
reaching loop_max, which can be equal to the number of running tasks of
the cfs. Make sure that imbalance will be decreased by at least 1.
misfit task is the other feature that doesn't handle correctly such
situation although it's probably more difficult to face the problem
because of the smaller number of CPUs and running tasks on heterogenous
system.
We can't simply ensure that task_h_load() returns at least one because it
would imply to handle underflow in other places.
Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <valentin.schneider@arm.com>
Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Tested-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: <stable@vger.kernel.org> # v4.4+
Link: https://lkml.kernel.org/r/20200710152426.16981-1-vincent.guittot@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ce3614daabea8a2d01c1dd17ae41d1ec5e5ae7db upstream.
While integrating rseq into glibc and replacing glibc's sched_getcpu
implementation with rseq, glibc's tests discovered an issue with
incorrect __rseq_abi.cpu_id field value right after the first time
a newly created process issues sched_setaffinity.
For the records, it triggers after building glibc and running tests, and
then issuing:
for x in {1..2000} ; do posix/tst-affinity-static & done
and shows up as:
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 2, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
error: Unexpected CPU 138, expected 0
This is caused by the scheduler invoking __set_task_cpu() directly from
sched_fork() and wake_up_new_task(), thus bypassing rseq_migrate() which
is done by set_task_cpu().
Add the missing rseq_migrate() to both functions. The only other direct
use of __set_task_cpu() is done by init_idle(), which does not involve a
user-space task.
Based on my testing with the glibc test-case, just adding rseq_migrate()
to wake_up_new_task() is sufficient to fix the observed issue. Also add
it to sched_fork() to keep things consistent.
The reason why this never triggered so far with the rseq/basic_test
selftest is unclear.
The current use of sched_getcpu(3) does not typically require it to be
always accurate. However, use of the __rseq_abi.cpu_id field within rseq
critical sections requires it to be accurate. If it is not accurate, it
can cause corruption in the per-cpu data targeted by rseq critical
sections in user-space.
Reported-By: Florian Weimer <fweimer@redhat.com>
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-By: Florian Weimer <fweimer@redhat.com>
Cc: stable@vger.kernel.org # v4.18+
Link: https://lkml.kernel.org/r/20200707201505.2632-1-mathieu.desnoyers@efficios.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit e2a71bdea81690b6ef11f4368261ec6f5b6891aa upstream.
When an expiration delta falls into the last level of the wheel, that delta
has be compared against the maximum possible delay and reduced to fit in if
necessary.
However instead of comparing the delta against the maximum, the code
compares the actual expiry against the maximum. Then instead of fixing the
delta to fit in, it sets the maximum delta as the expiry value.
This can result in various undesired outcomes, the worst possible one
being a timer expiring 15 days ahead to fire immediately.
Fixes: 500462a9de65 ("timers: Switch to a non-cascading wheel")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200717140551.29076-2-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 30c66fc30ee7a98c4f3adf5fb7e213b61884474f upstream.
When a timer is enqueued with a negative delta (ie: expiry is below
base->clk), it gets added to the wheel as expiring now (base->clk).
Yet the value that gets stored in base->next_expiry, while calling
trigger_dyntick_cpu(), is the initial timer->expires value. The
resulting state becomes:
base->next_expiry < base->clk
On the next timer enqueue, forward_timer_base() may accidentally
rewind base->clk. As a possible outcome, timers may expire way too
early, the worst case being that the highest wheel levels get spuriously
processed again.
To prevent from that, make sure that base->next_expiry doesn't get below
base->clk.
Fixes: a683f390b93f ("timers: Forward the wheel clock whenever possible")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/20200703010657.2302-1-frederic@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit ad0f75e5f57ccbceec13274e1e242f2b5a6397ed ]
When we clone a socket in sk_clone_lock(), its sk_cgrp_data is
copied, so the cgroup refcnt must be taken too. And, unlike the
sk_alloc() path, sock_update_netprioidx() is not called here.
Therefore, it is safe and necessary to grab the cgroup refcnt
even when cgroup_sk_alloc is disabled.
sk_clone_lock() is in BH context anyway, the in_interrupt()
would terminate this function if called there. And for sk_alloc()
skcd->val is always zero. So it's safe to factor out the code
to make it more readable.
The global variable 'cgroup_sk_alloc_disabled' is used to determine
whether to take these reference counts. It is impossible to make
the reference counting correct unless we save this bit of information
in skcd->val. So, add a new bit there to record whether the socket
has already taken the reference counts. This obviously relies on
kmalloc() to align cgroup pointers to at least 4 bytes,
ARCH_KMALLOC_MINALIGN is certainly larger than that.
This bug seems to be introduced since the beginning, commit
d979a39d7242 ("cgroup: duplicate cgroup reference when cloning sockets")
tried to fix it but not compeletely. It seems not easy to trigger until
the recent commit 090e28b229af
("netprio_cgroup: Fix unlimited memory leak of v2 cgroups") was merged.
Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup")
Reported-by: Cameron Berkenpas <cam@neo-zeon.de>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reported-by: Daniël Sonck <dsonck92@gmail.com>
Reported-by: Zhang Qiang <qiang.zhang@windriver.com>
Tested-by: Cameron Berkenpas <cam@neo-zeon.de>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Zefan Li <lizefan@huawei.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Roman Gushchin <guro@fb.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 63960260457a02af2a6cb35d75e6bdb17299c882 upstream.
When evaluating access control over kallsyms visibility, credentials at
open() time need to be used, not the "current" creds (though in BPF's
case, this has likely always been the same). Plumb access to associated
file->f_cred down through bpf_dump_raw_ok() and its callers now that
kallsysm_show_value() has been refactored to take struct cred.
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: bpf@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: 7105e828c087 ("bpf: allow for correlation of maps and helpers in dump")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 60f7bb66b88b649433bf700acfc60c3f24953871 upstream.
The kprobe show() functions were using "current"'s creds instead
of the file opener's creds for kallsyms visibility. Fix to use
seq_file->file->f_cred.
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 81365a947de4 ("kprobes: Show address of kprobes if kallsyms does")
Fixes: ffb9bd68ebdb ("kprobes: Show blacklist addresses as same as kallsyms does")
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit b25a7c5af9051850d4f3d93ca500056ab6ec724b upstream.
The printing of section addresses in /sys/module/*/sections/* was not
using the correct credentials to evaluate visibility.
Before:
# cat /sys/module/*/sections/.*text
0xffffffffc0458000
...
# capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text"
0xffffffffc0458000
...
After:
# cat /sys/module/*/sections/*.text
0xffffffffc0458000
...
# capsh --drop=CAP_SYSLOG -- -c "cat /sys/module/*/sections/.*text"
0x0000000000000000
...
Additionally replaces the existing (safe) /proc/modules check with
file->f_cred for consistency.
Reported-by: Dominik Czarnota <dominik.czarnota@trailofbits.com>
Fixes: be71eda5383f ("module: Fix display of wrong module .text address")
Cc: stable@vger.kernel.org
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit ed66f991bb19d94cae5d38f77de81f96aac7813f upstream.
In order to gain access to the open file's f_cred for kallsym visibility
permission checks, refactor the module section attributes to use the
bin_attribute instead of attribute interface. Additionally removes the
redundant "name" struct member.
Cc: stable@vger.kernel.org
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 160251842cd35a75edfb0a1d76afa3eb674ff40a upstream.
In order to perform future tests against the cred saved during open(),
switch kallsyms_show_value() to operate on a cred, and have all current
callers pass current_cred(). This makes it very obvious where callers
are checking the wrong credential in their "read" contexts. These will
be fixed in the coming patches.
Additionally switch return value to bool, since it is always used as a
direct permission check, not a 0-on-success, negative-on-error style
function return.
Cc: stable@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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fix mask corruption
[ Upstream commit fd844ba9ae59b51e34e77105d79f8eca780b3bd6 ]
This function is concerned with the long-term CPU mask, not the
transitory mask the task might have while migrate disabled. Before
this patch, if a task was migrate-disabled at the time
__set_cpus_allowed_ptr() was called, and the new mask happened to be
equal to the CPU that the task was running on, then the mask update
would be lost.
Signed-off-by: Scott Wood <swood@redhat.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lkml.kernel.org/r/20200617121742.cpxppyi7twxmpin7@linutronix.de
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 440ab9e10e2e6e5fd677473ee6f9e3af0f6904d6 ]
At times when I'm using kgdb I see a splat on my console about
suspicious RCU usage. I managed to come up with a case that could
reproduce this that looked like this:
WARNING: suspicious RCU usage
5.7.0-rc4+ #609 Not tainted
-----------------------------
kernel/pid.c:395 find_task_by_pid_ns() needs rcu_read_lock() protection!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
3 locks held by swapper/0/1:
#0: ffffff81b6b8e988 (&dev->mutex){....}-{3:3}, at: __device_attach+0x40/0x13c
#1: ffffffd01109e9e8 (dbg_master_lock){....}-{2:2}, at: kgdb_cpu_enter+0x20c/0x7ac
#2: ffffffd01109ea90 (dbg_slave_lock){....}-{2:2}, at: kgdb_cpu_enter+0x3ec/0x7ac
stack backtrace:
CPU: 7 PID: 1 Comm: swapper/0 Not tainted 5.7.0-rc4+ #609
Hardware name: Google Cheza (rev3+) (DT)
Call trace:
dump_backtrace+0x0/0x1b8
show_stack+0x1c/0x24
dump_stack+0xd4/0x134
lockdep_rcu_suspicious+0xf0/0x100
find_task_by_pid_ns+0x5c/0x80
getthread+0x8c/0xb0
gdb_serial_stub+0x9d4/0xd04
kgdb_cpu_enter+0x284/0x7ac
kgdb_handle_exception+0x174/0x20c
kgdb_brk_fn+0x24/0x30
call_break_hook+0x6c/0x7c
brk_handler+0x20/0x5c
do_debug_exception+0x1c8/0x22c
el1_sync_handler+0x3c/0xe4
el1_sync+0x7c/0x100
rpmh_rsc_probe+0x38/0x420
platform_drv_probe+0x94/0xb4
really_probe+0x134/0x300
driver_probe_device+0x68/0x100
__device_attach_driver+0x90/0xa8
bus_for_each_drv+0x84/0xcc
__device_attach+0xb4/0x13c
device_initial_probe+0x18/0x20
bus_probe_device+0x38/0x98
device_add+0x38c/0x420
If I understand properly we should just be able to blanket kgdb under
one big RCU read lock and the problem should go away. We'll add it to
the beast-of-a-function known as kgdb_cpu_enter().
With this I no longer get any splats and things seem to work fine.
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200602154729.v2.1.I70e0d4fd46d5ed2aaf0c98a355e8e1b7a5bb7e4e@changeid
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 9818427c6270a9ce8c52c8621026fe9cebae0f92 ]
Writing to the sysctl of a sched_domain->flags directly updates the value of
the field, and goes nowhere near update_top_cache_domain(). This means that
the cached domain pointers can end up containing stale data (e.g. the
domain pointed to doesn't have the relevant flag set anymore).
Explicit domain walks that check for flags will be affected by
the write, but this won't be in sync with the cached pointers which will
still point to the domains that were cached at the last sched_domain
build.
In other words, writing to this interface is playing a dangerous game. It
could be made to trigger an update of the cached sched_domain pointers when
written to, but this does not seem to be worth the trouble. Make it
read-only.
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200415210512.805-3-valentin.schneider@arm.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 097350d1c6e1f5808cae142006f18a0bbc57018d upstream.
Currently the ring buffer makes events that happen in interrupts that preempt
another event have a delta of zero. (Hopefully we can change this soon). But
this is to deal with the races of updating a global counter with lockless
and nesting functions updating deltas.
With the addition of absolute time stamps, the time extend didn't follow
this rule. A time extend can happen if two events happen longer than 2^27
nanoseconds appart, as the delta time field in each event is only 27 bits.
If that happens, then a time extend is injected with 2^59 bits of
nanoseconds to use (18 years). But if the 2^27 nanoseconds happen between
two events, and as it is writing the event, an interrupt triggers, it will
see the 2^27 difference as well and inject a time extend of its own. But a
recent change made the time extend logic not take into account the nesting,
and this can cause two time extend deltas to happen moving the time stamp
much further ahead than the current time. This gets all reset when the ring
buffer moves to the next page, but that can cause time to appear to go
backwards.
This was observed in a trace-cmd recording, and since the data is saved in a
file, with trace-cmd report --debug, it was possible to see that this indeed
did happen!
bash-52501 110d... 81778.908247: sched_switch: bash:52501 [120] S ==> swapper/110:0 [120] [12770284:0x2e8:64]
<idle>-0 110d... 81778.908757: sched_switch: swapper/110:0 [120] R ==> bash:52501 [120] [509947:0x32c:64]
TIME EXTEND: delta:306454770 length:0
bash-52501 110.... 81779.215212: sched_swap_numa: src_pid=52501 src_tgid=52388 src_ngid=52501 src_cpu=110 src_nid=2 dst_pid=52509 dst_tgid=52388 dst_ngid=52501 dst_cpu=49 dst_nid=1 [0:0x378:48]
TIME EXTEND: delta:306458165 length:0
bash-52501 110dNh. 81779.521670: sched_wakeup: migration/110:565 [0] success=1 CPU:110 [0:0x3b4:40]
and at the next page, caused the time to go backwards:
bash-52504 110d... 81779.685411: sched_switch: bash:52504 [120] S ==> swapper/110:0 [120] [8347057:0xfb4:64]
CPU:110 [SUBBUFFER START] [81779379165886:0x1320000]
<idle>-0 110dN.. 81779.379166: sched_wakeup: bash:52504 [120] success=1 CPU:110 [0:0x10:40]
<idle>-0 110d... 81779.379167: sched_switch: swapper/110:0 [120] R ==> bash:52504 [120] [1168:0x3c:64]
Link: https://lkml.kernel.org/r/20200622151815.345d1bf5@oasis.local.home
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: dc4e2801d400b ("ring-buffer: Redefine the unimplemented RINGBUF_TYPE_TIME_STAMP")
Reported-by: Julia Lawall <julia.lawall@inria.fr>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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commit 6784beada631800f2c5afd567e5628c843362cee upstream.
Fix the event trigger to accept redundant spaces in
the trigger input.
For example, these return -EINVAL
echo " traceon" > events/ftrace/print/trigger
echo "traceon if common_pid == 0" > events/ftrace/print/trigger
echo "disable_event:kmem:kmalloc " > events/ftrace/print/trigger
But these are hard to find what is wrong.
To fix this issue, use skip_spaces() to remove spaces
in front of actual tokens, and set NULL if there is no
token.
Link: http://lkml.kernel.org/r/159262476352.185015.5261566783045364186.stgit@devnote2
Cc: Tom Zanussi <zanussi@kernel.org>
Cc: stable@vger.kernel.org
Fixes: 85f2b08268c0 ("tracing: Add basic event trigger framework")
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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[ Upstream commit 1b0b283648163dae2a214ca28ed5a99f62a77319 ]
We use one blktrace per request_queue, that means one per the entire
disk. So we cannot run one blktrace on say /dev/vda and then /dev/vda1,
or just two calls on /dev/vda.
We check for concurrent setup only at the very end of the blktrace setup though.
If we try to run two concurrent blktraces on the same block device the
second one will fail, and the first one seems to go on. However when
one tries to kill the first one one will see things like this:
The kernel will show these:
```
debugfs: File 'dropped' in directory 'nvme1n1' already present!
debugfs: File 'msg' in directory 'nvme1n1' already present!
debugfs: File 'trace0' in directory 'nvme1n1' already present!
``
And userspace just sees this error message for the second call:
```
blktrace /dev/nvme1n1
BLKTRACESETUP(2) /dev/nvme1n1 failed: 5/Input/output error
```
The first userspace process #1 will also claim that the files
were taken underneath their nose as well. The files are taken
away form the first process given that when the second blktrace
fails, it will follow up with a BLKTRACESTOP and BLKTRACETEARDOWN.
This means that even if go-happy process #1 is waiting for blktrace
data, we *have* been asked to take teardown the blktrace.
This can easily be reproduced with break-blktrace [0] run_0005.sh test.
Just break out early if we know we're already going to fail, this will
prevent trying to create the files all over again, which we know still
exist.
[0] https://github.com/mcgrof/break-blktrace
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 6743ad432ec92e680cd0d9db86cb17b949cf5a43 ]
Anders reported that the lockdep warns that suspicious
RCU list usage in register_kprobe() (detected by
CONFIG_PROVE_RCU_LIST.) This is because get_kprobe()
access kprobe_table[] by hlist_for_each_entry_rcu()
without rcu_read_lock.
If we call get_kprobe() from the breakpoint handler context,
it is run with preempt disabled, so this is not a problem.
But in other cases, instead of rcu_read_lock(), we locks
kprobe_mutex so that the kprobe_table[] is not updated.
So, current code is safe, but still not good from the view
point of RCU.
Joel suggested that we can silent that warning by passing
lockdep_is_held() to the last argument of
hlist_for_each_entry_rcu().
Add lockdep_is_held(&kprobe_mutex) at the end of the
hlist_for_each_entry_rcu() to suppress the warning.
Link: http://lkml.kernel.org/r/158927055350.27680.10261450713467997503.stgit@devnote2
Reported-by: Anders Roxell <anders.roxell@linaro.org>
Suggested-by: Joel Fernandes <joel@joelfernandes.org>
Reviewed-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 740797ce3a124b7dd22b7fb832d87bc8fba1cf6f ]
syzbot reported the following warning:
WARNING: CPU: 1 PID: 6351 at kernel/sched/deadline.c:628
enqueue_task_dl+0x22da/0x38a0 kernel/sched/deadline.c:1504
At deadline.c:628 we have:
623 static inline void setup_new_dl_entity(struct sched_dl_entity *dl_se)
624 {
625 struct dl_rq *dl_rq = dl_rq_of_se(dl_se);
626 struct rq *rq = rq_of_dl_rq(dl_rq);
627
628 WARN_ON(dl_se->dl_boosted);
629 WARN_ON(dl_time_before(rq_clock(rq), dl_se->deadline));
[...]
}
Which means that setup_new_dl_entity() has been called on a task
currently boosted. This shouldn't happen though, as setup_new_dl_entity()
is only called when the 'dynamic' deadline of the new entity
is in the past w.r.t. rq_clock and boosted tasks shouldn't verify this
condition.
Digging through the PI code I noticed that what above might in fact happen
if an RT tasks blocks on an rt_mutex hold by a DEADLINE task. In the
first branch of boosting conditions we check only if a pi_task 'dynamic'
deadline is earlier than mutex holder's and in this case we set mutex
holder to be dl_boosted. However, since RT 'dynamic' deadlines are only
initialized if such tasks get boosted at some point (or if they become
DEADLINE of course), in general RT 'dynamic' deadlines are usually equal
to 0 and this verifies the aforementioned condition.
Fix it by checking that the potential donor task is actually (even if
temporary because in turn boosted) running at DEADLINE priority before
using its 'dynamic' deadline value.
Fixes: 2d3d891d3344 ("sched/deadline: Add SCHED_DEADLINE inheritance logic")
Reported-by: syzbot+119ba87189432ead09b4@syzkaller.appspotmail.com
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Daniel Bristot de Oliveira <bristot@redhat.com>
Tested-by: Daniel Wagner <dwagner@suse.de>
Link: https://lkml.kernel.org/r/20181119153201.GB2119@localhost.localdomain
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit ce9bc3b27f2a21a7969b41ffb04df8cf61bd1592 ]
syzbot reported the following warning triggered via SYSC_sched_setattr():
WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 setup_new_dl_entity /kernel/sched/deadline.c:594 [inline]
WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_dl_entity /kernel/sched/deadline.c:1370 [inline]
WARNING: CPU: 0 PID: 6973 at kernel/sched/deadline.c:593 enqueue_task_dl+0x1c17/0x2ba0 /kernel/sched/deadline.c:1441
This happens because the ->dl_boosted flag is currently not initialized by
__dl_clear_params() (unlike the other flags) and setup_new_dl_entity()
rightfully complains about it.
Initialize dl_boosted to 0.
Fixes: 2d3d891d3344 ("sched/deadline: Add SCHED_DEADLINE inheritance logic")
Reported-by: syzbot+5ac8bac25f95e8b221e7@syzkaller.appspotmail.com
Signed-off-by: Juri Lelli <juri.lelli@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Daniel Wagner <dwagner@suse.de>
Link: https://lkml.kernel.org/r/20200617072919.818409-1-juri.lelli@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit d8fe449a9c51a37d844ab607e14e2f5c657d3cf2 ]
Attaching to these hooks can break iptables because its optval is
usually quite big, or at least bigger than the current PAGE_SIZE limit.
David also mentioned some SCTP options can be big (around 256k).
For such optvals we expose only the first PAGE_SIZE bytes to
the BPF program. BPF program has two options:
1. Set ctx->optlen to 0 to indicate that the BPF's optval
should be ignored and the kernel should use original userspace
value.
2. Set ctx->optlen to something that's smaller than the PAGE_SIZE.
v5:
* use ctx->optlen == 0 with trimmed buffer (Alexei Starovoitov)
* update the docs accordingly
v4:
* use temporary buffer to avoid optval == optval_end == NULL;
this removes the corner case in the verifier that might assume
non-zero PTR_TO_PACKET/PTR_TO_PACKET_END.
v3:
* don't increase the limit, bypass the argument
v2:
* proper comments formatting (Jakub Kicinski)
Fixes: 0d01da6afc54 ("bpf: implement getsockopt and setsockopt hooks")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Cc: David Laight <David.Laight@ACULAB.COM>
Link: https://lore.kernel.org/bpf/20200617010416.93086-1-sdf@google.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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[ Upstream commit 99c51064fb06146b3d494b745c947e438a10aaa7 ]
Syzkaller discovered that creating a hash of type devmap_hash with a large
number of entries can hit the memory allocator limit for allocating
contiguous memory regions. There's really no reason to use kmalloc_array()
directly in the devmap code, so just switch it to the existing
bpf_map_area_alloc() function that is used elsewhere.
Fixes: 6f9d451ab1a3 ("xdp: Add devmap_hash map type for looking up devices by hashed index")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://lore.kernel.org/bpf/20200616142829.114173-1-toke@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
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commit 9b38cc704e844e41d9cf74e647bff1d249512cb3 upstream.
Ziqian reported lockup when adding retprobe on _raw_spin_lock_irqsave.
My test was also able to trigger lockdep output:
============================================
WARNING: possible recursive locking detected
5.6.0-rc6+ #6 Not tainted
--------------------------------------------
sched-messaging/2767 is trying to acquire lock:
ffffffff9a492798 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_hash_lock+0x52/0xa0
but task is already holding lock:
ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&(kretprobe_table_locks[i].lock));
lock(&(kretprobe_table_locks[i].lock));
*** DEADLOCK ***
May be due to missing lock nesting notation
1 lock held by sched-messaging/2767:
#0: ffffffff9a491a18 (&(kretprobe_table_locks[i].lock)){-.-.}, at: kretprobe_trampoline+0x0/0x50
stack backtrace:
CPU: 3 PID: 2767 Comm: sched-messaging Not tainted 5.6.0-rc6+ #6
Call Trace:
dump_stack+0x96/0xe0
__lock_acquire.cold.57+0x173/0x2b7
? native_queued_spin_lock_slowpath+0x42b/0x9e0
? lockdep_hardirqs_on+0x590/0x590
? __lock_acquire+0xf63/0x4030
lock_acquire+0x15a/0x3d0
? kretprobe_hash_lock+0x52/0xa0
_raw_spin_lock_irqsave+0x36/0x70
? kretprobe_hash_lock+0x52/0xa0
kretprobe_hash_lock+0x52/0xa0
trampoline_handler+0xf8/0x940
? kprobe_fault_handler+0x380/0x380
? find_held_lock+0x3a/0x1c0
kretprobe_trampoline+0x25/0x50
? lock_acquired+0x392/0xbc0
? _raw_spin_lock_irqsave+0x50/0x70
? __get_valid_kprobe+0x1f0/0x1f0
? _raw_spin_unlock_irqrestore+0x3b/0x40
? finish_task_switch+0x4b9/0x6d0
? __switch_to_asm+0x34/0x70
? __switch_to_asm+0x40/0x70
The code within the kretprobe handler checks for probe reentrancy,
so we won't trigger any _raw_spin_lock_irqsave probe in there.
The problem is in outside kprobe_flush_task, where we call:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave
where _raw_spin_lock_irqsave triggers the kretprobe and installs
kretprobe_trampoline handler on _raw_spin_lock_irqsave return.
The kretprobe_trampoline handler is then executed with already
locked kretprobe_table_locks, and first thing it does is to
lock kretprobe_table_locks ;-) the whole lockup path like:
kprobe_flush_task
kretprobe_table_lock
raw_spin_lock_irqsave
_raw_spin_lock_irqsave ---> probe triggered, kretprobe_trampoline installed
---> kretprobe_table_locks locked
kretprobe_trampoline
trampoline_handler
kretprobe_hash_lock(current, &head, &flags); <--- deadlock
Adding kprobe_busy_begin/end helpers that mark code with fake
probe installed to prevent triggering of another kprobe within
this code.
Using these helpers in kprobe_flush_task, so the probe recursion
protection check is hit and the probe is never set to prevent
above lockup.
Link: http://lkml.kernel.org/r/158927059835.27680.7011202830041561604.stgit@devnote2
Fixes: ef53d9c5e4da ("kprobes: improve kretprobe scalability with hashed locking")
Cc: Ingo Molnar <mingo@kernel.org>
Cc: "Gustavo A . R . Silva" <gustavoars@kernel.org>
Cc: Anders Roxell <anders.roxell@linaro.org>
Cc: "Naveen N . Rao" <naveen.n.rao@linux.ibm.com>
Cc: Anil S Keshavamurthy <anil.s.keshavamurthy@intel.com>
Cc: David Miller <davem@davemloft.net>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org
Reported-by: "Ziqian SUN (Zamir)" <zsun@redhat.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Masahiro Yamada
Thomas Gleixner
Qais Yousef
Chris Wilson
Luis Chamberlain
Liang Chen
Hugh Dickins
Wei Yongjun
Kees Cook
Steven Rostedt (VMware)
Kevin Hao
Muchun Song
Chengming Zhou
Guenter Roeck
Peng Liu
Vincent Guittot
Peter Zijlstra
Lorenz Bauer
Willy Tarreau
Andrii Nakryiko
Oleg Nesterov
Mathieu Desnoyers
Frederic Weisbecker
Cong Wang
Scott Wood
Douglas Anderson
Valentin Schneider
Masami Hiramatsu
Juri Lelli
Stanislav Fomichev
Toke Høiland-Jørgensen
Jiri Olsa