| Age | Commit message (Collapse) | Author |
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The wakeup in preemptive (wip) monitor verifies if the
wakeup events always take place with preemption disabled:
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v
#==================#
H preemptive H <+
#==================# |
| |
| preempt_disable | preempt_enable
v |
sched_waking +------------------+ |
+--------------- | | |
| | non_preemptive | |
+--------------> | | -+
+------------------+
The wakeup event always takes place with preemption disabled because
of the scheduler synchronization. However, because the preempt_count
and its trace event are not atomic with regard to interrupts, some
inconsistencies might happen.
The documentation illustrates one of these cases.
Link: https://lkml.kernel.org/r/c98ca678df81115fddc04921b3c79720c836b18f.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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THIS CODE IS NOT LINKED TO THE MAKEFILE.
This model does not compile because it lacks the instrumentation
part, which will be added next. In the typical case, there will be
only one patch, but it was split into two patches for educational
purposes.
This is the direct output this command line:
$ dot2k -d tools/verification/models/wip.dot -t per_cpu
Link: https://lkml.kernel.org/r/5eb7a9118917e8a814c5e49853a72fc62be0a101.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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Add the runtime-verification.rst document, explaining the basics of RV
and how to use the interface.
Link: https://lkml.kernel.org/r/4be7d1a88ab1e2eb0767521e1ab52a149a154bc4.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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In Linux terms, the runtime verification monitors are encapsulated
inside the "RV monitor" abstraction. The "RV monitor" includes a set
of instances of the monitor (per-cpu monitor, per-task monitor, and
so on), the helper functions that glue the monitor to the system
reference model, and the trace output as a reaction for event parsing
and exceptions, as depicted below:
Linux +----- RV Monitor ----------------------------------+ Formal
Realm | | Realm
+-------------------+ +----------------+ +-----------------+
| Linux kernel | | Monitor | | Reference |
| Tracing | -> | Instance(s) | <- | Model |
| (instrumentation) | | (verification) | | (specification) |
+-------------------+ +----------------+ +-----------------+
| | |
| V |
| +----------+ |
| | Reaction | |
| +--+--+--+-+ |
| | | | |
| | | +-> trace output ? |
+------------------------|--|----------------------+
| +----> panic ?
+-------> <user-specified>
Add the rv/da_monitor.h, enabling automatic code generation for the
*Monitor Instance(s)* using C macros, and code to support it.
The benefits of the usage of macro for monitor synthesis are 3-fold as it:
- Reduces the code duplication;
- Facilitates the bug fix/improvement;
- Avoids the case of developers changing the core of the monitor code
to manipulate the model in a (let's say) non-standard way.
This initial implementation presents three different types of monitor
instances:
- DECLARE_DA_MON_GLOBAL(name, type)
- DECLARE_DA_MON_PER_CPU(name, type)
- DECLARE_DA_MON_PER_TASK(name, type)
The first declares the functions for a global deterministic automata monitor,
the second for monitors with per-cpu instances, and the third with per-task
instances.
Link: https://lkml.kernel.org/r/51b0bf425a281e226dfeba7401d2115d6091f84e.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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A runtime monitor can cause a reaction to the detection of an
exception on the model's execution. By default, the monitors have
tracing reactions, printing the monitor output via tracepoints.
But other reactions can be added (on-demand) via this interface.
The user interface resembles the kernel tracing interface and
presents these files:
"available_reactors"
- Reading shows the available reactors, one per line.
For example:
# cat available_reactors
nop
panic
printk
"reacting_on"
- It is an on/off general switch for reactors, disabling
all reactions.
"monitors/MONITOR/reactors"
- List available reactors, with the select reaction for the given
MONITOR inside []. The default one is the nop (no operation)
reactor.
- Writing the name of a reactor enables it to the given
MONITOR.
For example:
# cat monitors/wip/reactors
[nop]
panic
printk
# echo panic > monitors/wip/reactors
# cat monitors/wip/reactors
nop
[panic]
printk
Link: https://lkml.kernel.org/r/1794eb994637457bdeaa6bad0b8263d2f7eece0c.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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RV is a lightweight (yet rigorous) method that complements classical
exhaustive verification techniques (such as model checking and
theorem proving) with a more practical approach to complex systems.
RV works by analyzing the trace of the system's actual execution,
comparing it against a formal specification of the system behavior.
RV can give precise information on the runtime behavior of the
monitored system while enabling the reaction for unexpected
events, avoiding, for example, the propagation of a failure on
safety-critical systems.
The development of this interface roots in the development of the
paper:
De Oliveira, Daniel Bristot; Cucinotta, Tommaso; De Oliveira, Romulo
Silva. Efficient formal verification for the Linux kernel. In:
International Conference on Software Engineering and Formal Methods.
Springer, Cham, 2019. p. 315-332.
And:
De Oliveira, Daniel Bristot. Automata-based formal analysis
and verification of the real-time Linux kernel. PhD Thesis, 2020.
The RV interface resembles the tracing/ interface on purpose. The current
path for the RV interface is /sys/kernel/tracing/rv/.
It presents these files:
"available_monitors"
- List the available monitors, one per line.
For example:
# cat available_monitors
wip
wwnr
"enabled_monitors"
- Lists the enabled monitors, one per line;
- Writing to it enables a given monitor;
- Writing a monitor name with a '!' prefix disables it;
- Truncating the file disables all enabled monitors.
For example:
# cat enabled_monitors
# echo wip > enabled_monitors
# echo wwnr >> enabled_monitors
# cat enabled_monitors
wip
wwnr
# echo '!wip' >> enabled_monitors
# cat enabled_monitors
wwnr
# echo > enabled_monitors
# cat enabled_monitors
#
Note that more than one monitor can be enabled concurrently.
"monitoring_on"
- It is an on/off general switcher for monitoring. Note
that it does not disable enabled monitors or detach events,
but stop the per-entity monitors of monitoring the events
received from the system. It resembles the "tracing_on" switcher.
"monitors/"
Each monitor will have its one directory inside "monitors/". There
the monitor specific files will be presented.
The "monitors/" directory resembles the "events" directory on
tracefs.
For example:
# cd monitors/wip/
# ls
desc enable
# cat desc
wakeup in preemptive per-cpu testing monitor.
# cat enable
0
For further information, see the comments in the header of
kernel/trace/rv/rv.c from this patch.
Link: https://lkml.kernel.org/r/a4bfe038f50cb047bfb343ad0e12b0e646ab308b.1659052063.git.bristot@kernel.org
Cc: Wim Van Sebroeck <wim@linux-watchdog.org>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marco Elver <elver@google.com>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Gabriele Paoloni <gpaoloni@redhat.com>
Cc: Juri Lelli <juri.lelli@redhat.com>
Cc: Clark Williams <williams@redhat.com>
Cc: Tao Zhou <tao.zhou@linux.dev>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: linux-trace-devel@vger.kernel.org
Signed-off-by: Daniel Bristot de Oliveira <bristot@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
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first waiter
With commit d257cc8cb8d5 ("locking/rwsem: Make handoff bit handling more
consistent"), the writer that sets the handoff bit can be interrupted
out without clearing the bit if the wait queue isn't empty. This disables
reader and writer optimistic lock spinning and stealing.
Now if a non-first writer in the queue is somehow woken up or a new
waiter enters the slowpath, it can't acquire the lock. This is not the
case before commit d257cc8cb8d5 as the writer that set the handoff bit
will clear it when exiting out via the out_nolock path. This is less
efficient as the busy rwsem stays in an unlock state for a longer time.
In some cases, this new behavior may cause lockups as shown in [1] and
[2].
This patch allows a non-first writer to ignore the handoff bit if it
is not originally set or initiated by the first waiter. This patch is
shown to be effective in fixing the lockup problem reported in [1].
[1] https://lore.kernel.org/lkml/20220617134325.GC30825@techsingularity.net/
[2] https://lore.kernel.org/lkml/3f02975c-1a9d-be20-32cf-f1d8e3dfafcc@oracle.com/
Fixes: d257cc8cb8d5 ("locking/rwsem: Make handoff bit handling more consistent")
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: John Donnelly <john.p.donnelly@oracle.com>
Tested-by: Mel Gorman <mgorman@techsingularity.net>
Link: https://lore.kernel.org/r/20220622200419.778799-1-longman@redhat.com
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Andrii Nakryiko says:
====================
bpf-next 2022-07-29
We've added 22 non-merge commits during the last 4 day(s) which contain
a total of 27 files changed, 763 insertions(+), 120 deletions(-).
The main changes are:
1) Fixes to allow setting any source IP with bpf_skb_set_tunnel_key() helper,
from Paul Chaignon.
2) Fix for bpf_xdp_pointer() helper when doing sanity checking, from Joanne Koong.
3) Fix for XDP frame length calculation, from Lorenzo Bianconi.
4) Libbpf BPF_KSYSCALL docs improvements and fixes to selftests to accommodate
s390x quirks with socketcall(), from Ilya Leoshkevich.
5) Allow/denylist and CI configs additions to selftests/bpf to improve BPF CI,
from Daniel Müller.
6) BPF trampoline + ftrace follow up fixes, from Song Liu and Xu Kuohai.
7) Fix allocation warnings in netdevsim, from Jakub Kicinski.
8) bpf_obj_get_opts() libbpf API allowing to provide file flags, from Joe Burton.
9) vsnprintf usage fix in bpf_snprintf_btf(), from Fedor Tokarev.
10) Various small fixes and clean ups, from Daniel Müller, Rongguang Wei,
Jörn-Thorben Hinz, Yang Li.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (22 commits)
bpf: Remove unneeded semicolon
libbpf: Add bpf_obj_get_opts()
netdevsim: Avoid allocation warnings triggered from user space
bpf: Fix NULL pointer dereference when registering bpf trampoline
bpf: Fix test_progs -j error with fentry/fexit tests
selftests/bpf: Bump internal send_signal/send_signal_tracepoint timeout
bpftool: Don't try to return value from void function in skeleton
bpftool: Replace sizeof(arr)/sizeof(arr[0]) with ARRAY_SIZE macro
bpf: btf: Fix vsnprintf return value check
libbpf: Support PPC in arch_specific_syscall_pfx
selftests/bpf: Adjust vmtest.sh to use local kernel configuration
selftests/bpf: Copy over libbpf configs
selftests/bpf: Sort configuration
selftests/bpf: Attach to socketcall() in test_probe_user
libbpf: Extend BPF_KSYSCALL documentation
bpf, devmap: Compute proper xdp_frame len redirecting frames
bpf: Fix bpf_xdp_pointer return pointer
selftests/bpf: Don't assign outer source IP to host
bpf: Set flow flag to allow any source IP in bpf_tunnel_key
geneve: Use ip_tunnel_key flow flags in route lookups
...
====================
Link: https://lore.kernel.org/r/20220729230948.1313527-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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The setup_profiling_timer() is mostly un-implemented by many
architectures. In many places it isn't guarded by CONFIG_PROFILE which is
needed for it to be used. Make it a weak symbol in kernel/profile.c and
remove the 'return -EINVAL' implementations from the kenrel.
There are a couple of architectures which do return 0 from the
setup_profiling_timer() function but they don't seem to do anything else
with it. To keep the /proc compatibility for now, leave these for a
future update or removal.
On ARM, this fixes the following sparse warning:
arch/arm/kernel/smp.c:793:5: warning: symbol 'setup_profiling_timer' was not declared. Should it be static?
Link: https://lkml.kernel.org/r/20220721195509.418205-1-ben-linux@fluff.org
Signed-off-by: Ben Dooks <ben-linux@fluff.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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The proc_dohung_task_timeout_secs() function is incorrectly marked
as having a __user buffer as argument 3. However this is not the
case and it is casing multiple sparse warnings. Fix the following
warnings by removing __user from the argument:
kernel/hung_task.c:237:52: warning: incorrect type in argument 3 (different address spaces)
kernel/hung_task.c:237:52: expected void *
kernel/hung_task.c:237:52: got void [noderef] __user *buffer
kernel/hung_task.c:287:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
kernel/hung_task.c:287:35: expected int ( [usertype] *proc_handler )( ... )
kernel/hung_task.c:287:35: got int ( * )( ... )
kernel/hung_task.c:295:35: warning: incorrect type in initializer (incompatible argument 3 (different address spaces))
kernel/hung_task.c:295:35: expected int ( [usertype] *proc_handler )( ... )
kernel/hung_task.c:295:35: got int ( * )( ... )
Link: https://lkml.kernel.org/r/20220714074744.189017-1-ben.dooks@sifive.com
Signed-off-by: Ben Dooks <ben.dooks@sifive.com>
Cc: <Conor.Dooley@microchip.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Eliminate the following coccicheck warning:
/kernel/bpf/trampoline.c:101:2-3: Unneeded semicolon
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220725222733.55613-1-yang.lee@linux.alibaba.com
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A panic was reported on arm64:
[ 44.517109] audit: type=1334 audit(1658859870.268:59): prog-id=19 op=LOAD
[ 44.622031] Unable to handle kernel NULL pointer dereference at
virtual address 0000000000000010
[ 44.624321] Mem abort info:
[ 44.625049] ESR = 0x0000000096000004
[ 44.625935] EC = 0x25: DABT (current EL), IL = 32 bits
[ 44.627182] SET = 0, FnV = 0
[ 44.627930] EA = 0, S1PTW = 0
[ 44.628684] FSC = 0x04: level 0 translation fault
[ 44.629788] Data abort info:
[ 44.630474] ISV = 0, ISS = 0x00000004
[ 44.631362] CM = 0, WnR = 0
[ 44.632041] user pgtable: 4k pages, 48-bit VAs, pgdp=0000000100ab5000
[ 44.633494] [0000000000000010] pgd=0000000000000000, p4d=0000000000000000
[ 44.635202] Internal error: Oops: 96000004 [#1] SMP
[ 44.636452] Modules linked in: xfs crct10dif_ce ghash_ce virtio_blk
virtio_console virtio_mmio qemu_fw_cfg
[ 44.638713] CPU: 2 PID: 1 Comm: systemd Not tainted 5.19.0-rc7 #1
[ 44.640164] Hardware name: QEMU KVM Virtual Machine, BIOS 0.0.0 02/06/2015
[ 44.641799] pstate: 00400005 (nzcv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 44.643404] pc : ftrace_set_filter_ip+0x24/0xa0
[ 44.644659] lr : bpf_trampoline_update.constprop.0+0x428/0x4a0
[ 44.646118] sp : ffff80000803b9f0
[ 44.646950] x29: ffff80000803b9f0 x28: ffff0b5d80364400 x27: ffff80000803bb48
[ 44.648721] x26: ffff8000085ad000 x25: ffff0b5d809d2400 x24: 0000000000000000
[ 44.650493] x23: 00000000ffffffed x22: ffff0b5dd7ea0900 x21: 0000000000000000
[ 44.652279] x20: 0000000000000000 x19: 0000000000000000 x18: ffffffffffffffff
[ 44.654067] x17: 0000000000000000 x16: 0000000000000000 x15: ffffffffffffffff
[ 44.655787] x14: ffff0b5d809d2498 x13: ffff0b5d809d2432 x12: 0000000005f5e100
[ 44.657535] x11: abcc77118461cefd x10: 000000000000005f x9 : ffffa7219cb5b190
[ 44.659254] x8 : ffffa7219c8e0000 x7 : 0000000000000000 x6 : ffffa7219db075e0
[ 44.661066] x5 : ffffa7219d3130e0 x4 : ffffa7219cab9da0 x3 : 0000000000000000
[ 44.662837] x2 : 0000000000000000 x1 : ffffa7219cb7a5c0 x0 : 0000000000000000
[ 44.664675] Call trace:
[ 44.665274] ftrace_set_filter_ip+0x24/0xa0
[ 44.666327] bpf_trampoline_update.constprop.0+0x428/0x4a0
[ 44.667696] __bpf_trampoline_link_prog+0xcc/0x1c0
[ 44.668834] bpf_trampoline_link_prog+0x40/0x64
[ 44.669919] bpf_tracing_prog_attach+0x120/0x490
[ 44.671011] link_create+0xe0/0x2b0
[ 44.671869] __sys_bpf+0x484/0xd30
[ 44.672706] __arm64_sys_bpf+0x30/0x40
[ 44.673678] invoke_syscall+0x78/0x100
[ 44.674623] el0_svc_common.constprop.0+0x4c/0xf4
[ 44.675783] do_el0_svc+0x38/0x4c
[ 44.676624] el0_svc+0x34/0x100
[ 44.677429] el0t_64_sync_handler+0x11c/0x150
[ 44.678532] el0t_64_sync+0x190/0x194
[ 44.679439] Code: 2a0203f4 f90013f5 2a0303f5 f9001fe1 (f9400800)
[ 44.680959] ---[ end trace 0000000000000000 ]---
[ 44.682111] Kernel panic - not syncing: Oops: Fatal exception
[ 44.683488] SMP: stopping secondary CPUs
[ 44.684551] Kernel Offset: 0x2721948e0000 from 0xffff800008000000
[ 44.686095] PHYS_OFFSET: 0xfffff4a380000000
[ 44.687144] CPU features: 0x010,00022811,19001080
[ 44.688308] Memory Limit: none
[ 44.689082] ---[ end Kernel panic - not syncing: Oops: Fatal exception ]---
It's caused by a NULL tr->fops passed to ftrace_set_filter_ip(). tr->fops
is initialized to NULL and is assigned to an allocated memory address if
CONFIG_DYNAMIC_FTRACE_WITH_DIRECT_CALLS is enabled. Since there is no
direct call on arm64 yet, the config can't be enabled.
To fix it, call ftrace_set_filter_ip() only if tr->fops is not NULL.
Fixes: 00963a2e75a8 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Reported-by: Bruno Goncalves <bgoncalv@redhat.com>
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Tested-by: Bruno Goncalves <bgoncalv@redhat.com>
Acked-by: Song Liu <songliubraving@fb.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20220728114048.3540461-1-xukuohai@huaweicloud.com
|
|
When multiple threads are attaching/detaching fentry/fexit programs to
the same trampoline, we may call register_fentry on the same trampoline
twice: register_fentry(), unregister_fentry(), then register_fentry again.
This causes ftrace_set_filter_ip() for the same ip on tr->fops twice,
which leaves duplicated ip in tr->fops. The extra ip is not cleaned up
properly on unregister and thus causes failures with further register in
register_ftrace_direct_multi():
register_ftrace_direct_multi()
{
...
for (i = 0; i < size; i++) {
hlist_for_each_entry(entry, &hash->buckets[i], hlist) {
if (ftrace_find_rec_direct(entry->ip))
goto out_unlock;
}
}
...
}
This can be triggered with parallel fentry/fexit tests with test_progs:
./test_progs -t fentry,fexit -j
Fix this by resetting tr->fops in ftrace_set_filter_ip(), so that there
will never be duplicated entries in tr->fops.
Fixes: 00963a2e75a8 ("bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)")
Reported-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220729194106.1207472-1-song@kernel.org
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|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq
Pull workqueue fix from Tejun Heo:
"Just one commit to suppress a spurious warning added during the 5.19
cycle"
* tag 'wq-for-5.19-rc8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Avoid a false warning in unbind_workers()
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|
Doing set_cpus_allowed_ptr() with wq_unbound_cpumask can be possible
fails and trigger the false warning.
Use cpu_possible_mask instead when wq_unbound_cpumask has no active CPUs.
It is very easy to trigger the warning:
Set wq_unbound_cpumask to a small set of CPUs.
Offline all the CPUs of wq_unbound_cpumask.
Offline an extra CPU and trigger the warning.
Fixes: 10a5a651e3af ("workqueue: Restrict kworker in the offline CPU pool running on housekeeping CPUs")
Signed-off-by: Lai Jiangshan <jiangshan.ljs@antgroup.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
Merge devfreq changes, PM QoS change, and power management tools and
documentation changes for v5.20-rc1:
- Add new devfreq driver for Mediatek CCI (Cache Coherent
Interconnect) (Johnson Wang).
- Convert the Samsung Exynos SoC Bus bindings to DT schema of
exynos-bus.c (Krzysztof Kozlowski).
- Address kernel-doc warnings by adding the description for unused
fucntion parameters in devfreq core (Mauro Carvalho Chehab).
- Use NULL to pass a null pointer rather than zero according to the
function propotype in imx-bus.c (Colin Ian King).
- Print error message instead of error interger value in
tegra30-devfreq.c (Dmitry Osipenko).
- Add checks to prevent setting negative frequency QoS limits for
CPUs (Shivnandan Kumar).
- Update the pm-graph suite of utilities to the latest revision 5.9
including multiple improvements (Todd Brandt).
- Drop pme_interrupt reference from the PCI power management
documentation (Mario Limonciello).
* pm-devfreq:
PM / devfreq: tegra30: Add error message for devm_devfreq_add_device()
PM / devfreq: imx-bus: use NULL to pass a null pointer rather than zero
PM / devfreq: shut up kernel-doc warnings
dt-bindings: interconnect: samsung,exynos-bus: convert to dtschema
PM / devfreq: mediatek: Introduce MediaTek CCI devfreq driver
dt-bindings: interconnect: Add MediaTek CCI dt-bindings
* pm-qos:
PM: QoS: Add check to make sure CPU freq is non-negative
* pm-tools:
pm-graph v5.9
* pm-docs:
Documentation: PM: Drop pme_interrupt reference
|
|
Merge core device power management changes for v5.20-rc1:
- Extend support for wakeirq to callback wrappers used during system
suspend and resume (Ulf Hansson).
- Defer waiting for device probe before loading a hibernation image
till the first actual device access to avoid possible deadlocks
reported by syzbot (Tetsuo Handa).
- Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP (Bjorn
Helgaas).
- Add Raptor Lake-P to the list of processors supported by the Intel
RAPL driver (George D Sworo).
- Add Alder Lake-N and Raptor Lake-P to the list of processors for
which Power Limit4 is supported in the Intel RAPL driver (Sumeet
Pawnikar).
- Make pm_genpd_remove() check genpd_debugfs_dir against NULL before
attempting to remove it (Hsin-Yi Wang).
- Change the Energy Model code to represent power in micro-Watts and
adjust its users accordingly (Lukasz Luba).
* pm-core:
PM: runtime: Extend support for wakeirq for force_suspend|resume
* pm-sleep:
PM: hibernate: defer device probing when resuming from hibernation
PM: wakeup: Unify device_init_wakeup() for PM_SLEEP and !PM_SLEEP
* powercap:
powercap: RAPL: Add Power Limit4 support for Alder Lake-N and Raptor Lake-P
powercap: intel_rapl: Add support for RAPTORLAKE_P
* pm-domains:
PM: domains: Ensure genpd_debugfs_dir exists before remove
* pm-em:
cpufreq: scmi: Support the power scale in micro-Watts in SCMI v3.1
firmware: arm_scmi: Get detailed power scale from perf
Documentation: EM: Switch to micro-Watts scale
PM: EM: convert power field to micro-Watts precision and align drivers
|
|
vsnprintf returns the number of characters which would have been written if
enough space had been available, excluding the terminating null byte. Thus,
the return value of 'len_left' means that the last character has been
dropped.
Signed-off-by: Fedor Tokarev <ftokarev@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Alan Maguire <alan.maguire@oracle.com>
Link: https://lore.kernel.org/bpf/20220711211317.GA1143610@laptop
|
|
No conflicts.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
|
|
The cgroup_update_dfl_csses() function updates css associations when a
cgroup's subtree_control file is modified. Any changes made to a cgroup's
subtree_control file, however, will only affect its descendants but not
the cgroup itself. So there is no point in migrating csses associated
with that cgroup. We can skip them instead.
Signed-off-by: Waiman Long <longman@redhat.com>
Reviewed-by: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
If a watch is being added to a queue, it needs to guard against
interference from addition of a new watch, manual removal of a watch and
removal of a watch due to some other queue being destroyed.
KEYCTL_WATCH_KEY guards against this for the same {key,queue} pair by
holding the key->sem writelocked and by holding refs on both the key and
the queue - but that doesn't prevent interaction from other {key,queue}
pairs.
While add_watch_to_object() does take the spinlock on the event queue,
it doesn't take the lock on the source's watch list. The assumption was
that the caller would prevent that (say by taking key->sem) - but that
doesn't prevent interference from the destruction of another queue.
Fix this by locking the watcher list in add_watch_to_object().
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Reported-by: syzbot+03d7b43290037d1f87ca@syzkaller.appspotmail.com
Signed-off-by: David Howells <dhowells@redhat.com>
cc: keyrings@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Since __post_watch_notification() walks wlist->watchers with only the
RCU read lock held, we need to use RCU methods to add to the list (we
already use RCU methods to remove from the list).
Fix add_watch_to_object() to use hlist_add_head_rcu() instead of
hlist_add_head() for that list.
Fixes: c73be61cede5 ("pipe: Add general notification queue support")
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
|
|
Debugfs node will be run-timely checked and so local variable
should be not passed to debugfs_create_ulong(). Fix it via
debugfs_create_file() to create io_tlb_used node and calculate
used io tlb number with fops_io_tlb_used attribute.
Fixes: 20347fca71a3 ("swiotlb: split up the global swiotlb lock")
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
make html doc reports a cryptic warning with the commit named below:
kernel/dma/mapping.c:258: WARNING: Option list ends without a blank
line; unexpected unindent.
Seems the parser is a bit fussy about the tabbing and having a single
space tab causes the warning. To suppress the warning add another
tab to the list and reindent everything.
Fixes: 7c2645a2a30a ("dma-mapping: allow EREMOTEIO return code for P2PDMA transfers")
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms into irq/core
Pull irqchip/genirq updates from Marc Zyngier:
* Core code update:
- Non-SMP IRQ affinity fixes, allowing UP kernel to behave similarly
to SMP ones for the purpose of interrupt affinity
- Let irq_set_chip_handler_name_locked() take a const struct irq_chip *
- Tidy-up the NOMAP irqdomain API variant
- Teach action_show() to use for_each_action_of_desc()
- Make irq_chip_request_resources_parent() allow the parent callback
to be optional
- Remove dynamic allocations from populate_parent_alloc_arg()
* New drivers:
- Merge the long awaited IRQ support for the LoongArch architecture,
with the provisional ACPICA update (to be reverted once the official
support lands)
- New Renesas RZ/G2L IRQC driver, equipped with its companion GPIO
driver
* Driver updates
- Optimise the hot path operations for the SiFive PLIC, trading the
locking for per-CPU priority masking masking operations which are
apparently faster
- Work around broken PLIC implementations that deal pretty badly with
edge-triggered interrupts. Flag two implementations as affected.
- Simplify the irq-stm32-exti driver, particularly the table that
remaps the interrupts from exti to the GIC, reducing the memory usage
- Convert the ocelot irq_chip to being immutable
- Check ioremap() return value in the MIPS GIC driver
- Move MMP driver init function declarations into the common .h
- The obligatory typo fixes
Link: https://lore.kernel.org/all/20220727192356.1860546-1-maz@kernel.org
|
|
30312730bd02 ("cgroup: Add "no" prefixed mount options") added "no" prefixed
mount options to allow turning them off and 6a010a49b63a ("cgroup: Make
!percpu threadgroup_rwsem operations optional") added one more "no" prefixed
mount option. However, Michal pointed out that the "no" prefixed options
aren't necessary in allowing mount options to be turned off:
# grep group /proc/mounts
cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,relatime,nsdelegate,memory_recursiveprot 0 0
# mount -o remount,nsdelegate,memory_recursiveprot none /sys/fs/cgroup
# grep cgroup /proc/mounts
cgroup2 /sys/fs/cgroup cgroup2 rw,relatime,nsdelegate,memory_recursiveprot 0 0
Note that this is different from the remount behavior when the mount(1) is
invoked without the device argument - "none":
# grep cgroup /proc/mounts
cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0
# mount -o remount,nsdelegate,memory_recursiveprot /sys/fs/cgroup
# grep cgroup /proc/mounts
cgroup2 /sys/fs/cgroup cgroup2 rw,nosuid,nodev,noexec,relatime,nsdelegate,memory_recursiveprot 0 0
While a bit confusing, given that there is a way to turn off the options,
there's no reason to have the explicit "no" prefixed options. Let's remove
them.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
|
|
Commit
4675ff05de2d ("kmemcheck: rip it out")
removed kmemcheck and its corresponding build config KMEMCHECK.
Commit
0f620cefd775 ("objtool: Rename "VMLINUX_VALIDATION" -> "NOINSTR_VALIDATION"")
renamed the debug config option.
Adjust x86_debug.config to those changes in debug configs.
Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220722121815.27535-1-lukas.bulwahn@gmail.com
|
|
In some circumstances it may be interesting to reconfigure the watchdog
from inside the kernel.
On PowerPC, this may helpful before and after a LPAR migration (LPM) is
initiated, because it implies some latencies, watchdog, and especially NMI
watchdog is expected to be triggered during this operation. Reconfiguring
the watchdog with a factor, would prevent it to happen too frequently
during LPM.
Rename lockup_detector_reconfigure() as __lockup_detector_reconfigure() and
create a new function lockup_detector_reconfigure() calling
__lockup_detector_reconfigure() under the protection of watchdog_mutex.
Signed-off-by: Laurent Dufour <ldufour@linux.ibm.com>
[mpe: Squash in build fix from Laurent, reported by Sachin]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20220713154729.80789-3-ldufour@linux.ibm.com
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|
CPU frequency should never be negative.
If some client driver calls freq_qos_update_request with a
negative value which will be very high in absolute terms,
then frequency QoS sets max CPU freq at fmax as it considers
it's absolute value but it will add plist node with negative
priority.
plist node has priority from INT_MIN (highest) to INT_MAX(lowest).
Once priority is set as negative, another client will not be able
to reduce CPU frequency.
Adding check to make sure CPU freq is non-negative will fix
this problem.
Signed-off-by: Shivnandan Kumar <quic_kshivnan@quicinc.com>
[ rjw: Changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
syzbot is reporting hung task at misc_open() [1], for there is a race
window of AB-BA deadlock which involves probe_count variable. Currently
wait_for_device_probe() from snapshot_open() from misc_open() can sleep
forever with misc_mtx held if probe_count cannot become 0.
When a device is probed by hub_event() work function, probe_count is
incremented before the probe function starts, and probe_count is
decremented after the probe function completed.
There are three cases that can prevent probe_count from dropping to 0.
(a) A device being probed stopped responding (i.e. broken/malicious
hardware).
(b) A process emulating a USB device using /dev/raw-gadget interface
stopped responding for some reason.
(c) New device probe requests keeps coming in before existing device
probe requests complete.
The phenomenon syzbot is reporting is (b). A process which is holding
system_transition_mutex and misc_mtx is waiting for probe_count to become
0 inside wait_for_device_probe(), but the probe function which is called
from hub_event() work function is waiting for the processes which are
blocked at mutex_lock(&misc_mtx) to respond via /dev/raw-gadget interface.
This patch mitigates (b) by deferring wait_for_device_probe() from
snapshot_open() to snapshot_write() and snapshot_ioctl(). Please note that
the possibility of (b) remains as long as any thread which is emulating a
USB device via /dev/raw-gadget interface can be blocked by uninterruptible
blocking operations (e.g. mutex_lock()).
Please also note that (a) and (c) are not addressed. Regarding (c), we
should change the code to wait for only one device which contains the
image for resuming from hibernation. I don't know how to address (a), for
use of timeout for wait_for_device_probe() might result in loss of user
data in the image. Maybe we should require the userland to wait for the
image device before opening /dev/snapshot interface.
Link: https://syzkaller.appspot.com/bug?extid=358c9ab4c93da7b7238c [1]
Reported-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot <syzbot+358c9ab4c93da7b7238c@syzkaller.appspotmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
|
|
Even if it is currently forbidden to XDP_REDIRECT a multi-frag xdp_frame into
a devmap, compute proper xdp_frame length in __xdp_enqueue and is_valid_dst
routines running xdp_get_frame_len().
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/894d99c01139e921bdb6868158ff8e67f661c072.1658596075.git.lorenzo@kernel.org
|
|
Add a flags member to the dma_map_ops structure with one flag to
indicate support for PCI P2PDMA.
Also, add a helper to check if a device supports PCI P2PDMA.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
Add PCI P2PDMA support for dma_direct_map_sg() so that it can map
PCI P2PDMA pages directly without a hack in the callers. This allows
for heterogeneous SGLs that contain both P2PDMA and regular pages.
A P2PDMA page may have three possible outcomes when being mapped:
1) If the data path between the two devices doesn't go through the
root port, then it should be mapped with a PCI bus address
2) If the data path goes through the host bridge, it should be mapped
normally, as though it were a CPU physical address
3) It is not possible for the two devices to communicate and thus
the mapping operation should fail (and it will return -EREMOTEIO).
SGL segments that contain PCI bus addresses are marked with
sg_dma_mark_pci_p2pdma() and are ignored when unmapped.
P2PDMA mappings are also failed if swiotlb needs to be used on the
mapping.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
Add EREMOTEIO error return to dma_map_sgtable() which will be used
by .map_sg() implementations that detect P2PDMA pages that the
underlying DMA device cannot access.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
|
|
* irq/misc-5.20:
: .
: Misc IRQ changes for 5.20:
:
: - Let irq_set_chip_handler_name_locked() take a const struct irq_chip *
:
: - Convert the ocelot irq_chip to being immutable (depends on the above)
:
: - Tidy-up the NOMAP irqdomain API variant
:
: - Teach action_show() to use for_each_action_of_desc()
:
: - Check ioremap() return value in the MIPS GIC driver
:
: - Move MMP driver init function declarations into the common .h
:
: - The obligatory typo fixes
: .
irqchip/mmp: Declare init functions in common header file
irqchip/mips-gic: Check the return value of ioremap() in gic_of_init()
genirq: Use for_each_action_of_desc in actions_show()
irqdomain: Use hwirq_max instead of revmap_size for NOMAP domains
irqdomain: Report irq number for NOMAP domains
irqchip/gic-v3: Fix comment typo
pinctrl: ocelot: Make irq_chip immutable
genirq: Allow irq_set_chip_handler_name_locked() to take a const irq_chip
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
In preparation for splitting io_uring up a bit, move it into its own
top level directory. It didn't really belong in fs/ anyway, as it's
not a file system only API.
This adds io_uring/ and moves the core files in there, and updates the
MAINTAINERS file for the new location.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
|
|
Currently when creating a specific group of trace events,
take kprobe event as example, the user must use the following format:
p:GRP/EVENT [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS],
which means user must enter EVENT name, one example is:
echo 'p:usb_gadget/config_usb_cfg_link config_usb_cfg_link $arg1' >> kprobe_events
It is not simple if there are too many entries because the event name is
the same as symbol name.
This change allows user to specify no EVENT name, format changed as:
p:GRP/ [MOD:]KSYM[+OFFS]|KADDR [FETCHARGS]
It will generate event name automatically and one example is:
echo 'p:usb_gadget/ config_usb_cfg_link $arg1' >> kprobe_events.
Link: https://lore.kernel.org/all/1656296348-16111-4-git-send-email-quic_linyyuan@quicinc.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
traceprobe_parse_event_name() already validate SYSTEM and EVENT name,
there is no need to call is_good_name() after it.
Link: https://lore.kernel.org/all/1656296348-16111-3-git-send-email-quic_linyyuan@quicinc.com/
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
Add trace_probe_log_set_index(1) to allow report correct error
if user input wrong SYSTEM.EVENT format.
Link: https://lore.kernel.org/all/1656296348-16111-2-git-send-email-quic_linyyuan@quicinc.com/
Reviewed-by: Tom Zanussi <zanussi@kernel.org>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Borislav Petkov:
"A single fix to correct a wrong BUG_ON() condition for deboosted
tasks"
* tag 'sched_urgent_for_v5.19_rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/deadline: Fix BUG_ON condition for deboosted tasks
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|
3942a9bd7b58 ("locking, rcu, cgroup: Avoid synchronize_sched() in
__cgroup_procs_write()") disabled percpu operations on threadgroup_rwsem
because the impiled synchronize_rcu() on write locking was pushing up the
latencies too much for android which constantly moves processes between
cgroups.
This makes the hotter paths - fork and exit - slower as they're always
forced into the slow path. There is no reason to force this on everyone
especially given that more common static usage pattern can now completely
avoid write-locking the rwsem. Write-locking is elided when turning on and
off controllers on empty sub-trees and CLONE_INTO_CGROUP enables seeding a
cgroup without grabbing the rwsem.
Restore the default percpu operations and introduce the mount option
"favordynmods" and config option CGROUP_FAVOR_DYNMODS for users who need
lower latencies for the dynamic operations.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutn� <mkoutny@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Dmitry Shmidt <dimitrysh@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
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We allow modifying these mount options via remount. Let's add "no" prefixed
variants so that they can be turned off too.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
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empty subtree
cgroup_update_dfl_csses() write-lock the threadgroup_rwsem as updating the
csses can trigger process migrations. However, if the subtree doesn't
contain any tasks, there aren't gonna be any cgroup migrations. This
condition can be trivially detected by testing whether
mgctx.preloaded_src_csets is empty. Elide write-locking threadgroup_rwsem if
the subtree is empty.
After this optimization, the usage pattern of creating a cgroup, enabling
the necessary controllers, and then seeding it with CLONE_INTO_CGROUP and
then removing the cgroup after it becomes empty doesn't need to write-lock
threadgroup_rwsem at all.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Michal Koutný <mkoutny@suse.com>
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Daniel Borkmann says:
====================
bpf-next 2022-07-22
We've added 73 non-merge commits during the last 12 day(s) which contain
a total of 88 files changed, 3458 insertions(+), 860 deletions(-).
The main changes are:
1) Implement BPF trampoline for arm64 JIT, from Xu Kuohai.
2) Add ksyscall/kretsyscall section support to libbpf to simplify tracing kernel
syscalls through kprobe mechanism, from Andrii Nakryiko.
3) Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel
function, from Song Liu & Jiri Olsa.
4) Add new kfunc infrastructure for netfilter's CT e.g. to insert and change
entries, from Kumar Kartikeya Dwivedi & Lorenzo Bianconi.
5) Add a ksym BPF iterator to allow for more flexible and efficient interactions
with kernel symbols, from Alan Maguire.
6) Bug fixes in libbpf e.g. for uprobe binary path resolution, from Dan Carpenter.
7) Fix BPF subprog function names in stack traces, from Alexei Starovoitov.
8) libbpf support for writing custom perf event readers, from Jon Doron.
9) Switch to use SPDX tag for BPF helper man page, from Alejandro Colomar.
10) Fix xsk send-only sockets when in busy poll mode, from Maciej Fijalkowski.
11) Reparent BPF maps and their charging on memcg offlining, from Roman Gushchin.
12) Multiple follow-up fixes around BPF lsm cgroup infra, from Stanislav Fomichev.
13) Use bootstrap version of bpftool where possible to speed up builds, from Pu Lehui.
14) Cleanup BPF verifier's check_func_arg() handling, from Joanne Koong.
15) Make non-prealloced BPF map allocations low priority to play better with
memcg limits, from Yafang Shao.
16) Fix BPF test runner to reject zero-length data for skbs, from Zhengchao Shao.
17) Various smaller cleanups and improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (73 commits)
bpf: Simplify bpf_prog_pack_[size|mask]
bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
bpf, x64: Allow to use caller address from stack
ftrace: Allow IPMODIFY and DIRECT ops on the same function
ftrace: Add modify_ftrace_direct_multi_nolock
bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test
bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF
selftests/bpf: Fix test_verifier failed test in unprivileged mode
selftests/bpf: Add negative tests for new nf_conntrack kfuncs
selftests/bpf: Add tests for new nf_conntrack kfuncs
selftests/bpf: Add verifier tests for trusted kfunc args
net: netfilter: Add kfuncs to set and change CT status
net: netfilter: Add kfuncs to set and change CT timeout
net: netfilter: Add kfuncs to allocate and insert CT
net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
bpf: Add documentation for kfuncs
bpf: Add support for forcing kfunc args to be trusted
bpf: Switch to new kfunc flags infrastructure
tools/resolve_btfids: Add support for 8-byte BTF sets
bpf: Introduce 8-byte BTF set
...
====================
Link: https://lore.kernel.org/r/20220722221218.29943-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Simplify the logic that selects bpf_prog_pack_size, and always use
(PMD_SIZE * num_possible_nodes()). This is a good tradeoff, as most of
the performance benefit observed is from less direct map fragmentation [0].
Also, module_alloc(4MB) may not allocate 4MB aligned memory. Therefore,
we cannot use (ptr & bpf_prog_pack_mask) to find the correct address of
bpf_prog_pack. Fix this by checking the header address falls in the range
of pack->ptr and (pack->ptr + bpf_prog_pack_size).
[0] https://lore.kernel.org/bpf/20220707223546.4124919-1-song@kernel.org/
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20220713204950.3015201-1-song@kernel.org
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When tracing a function with IPMODIFY ftrace_ops (livepatch), the bpf
trampoline must follow the instruction pointer saved on stack. This needs
extra handling for bpf trampolines with BPF_TRAMP_F_CALL_ORIG flag.
Implement bpf_tramp_ftrace_ops_func and use it for the ftrace_ops used
by BPF trampoline. This enables tracing functions with livepatch.
This also requires moving bpf trampoline to *_ftrace_direct_mult APIs.
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/all/20220602193706.2607681-2-song@kernel.org/
Link: https://lore.kernel.org/bpf/20220720002126.803253-5-song@kernel.org
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IPMODIFY (livepatch) and DIRECT (bpf trampoline) ops are both important
users of ftrace. It is necessary to allow them work on the same function
at the same time.
First, DIRECT ops no longer specify IPMODIFY flag. Instead, DIRECT flag is
handled together with IPMODIFY flag in __ftrace_hash_update_ipmodify().
Then, a callback function, ops_func, is added to ftrace_ops. This is used
by ftrace core code to understand whether the DIRECT ops can share with an
IPMODIFY ops. To share with IPMODIFY ops, the DIRECT ops need to implement
the callback function and adjust the direct trampoline accordingly.
If DIRECT ops is attached before the IPMODIFY ops, ftrace core code calls
ENABLE_SHARE_IPMODIFY_PEER on the DIRECT ops before registering the
IPMODIFY ops.
If IPMODIFY ops is attached before the DIRECT ops, ftrace core code calls
ENABLE_SHARE_IPMODIFY_SELF in __ftrace_hash_update_ipmodify. Owner of the
DIRECT ops may return 0 if the DIRECT trampoline can share with IPMODIFY,
so error code otherwise. The error code is propagated to
register_ftrace_direct_multi so that onwer of the DIRECT trampoline can
handle it properly.
For more details, please refer to comment before enum ftrace_ops_cmd.
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/all/20220602193706.2607681-2-song@kernel.org/
Link: https://lore.kernel.org/all/20220718055449.3960512-1-song@kernel.org/
Link: https://lore.kernel.org/bpf/20220720002126.803253-3-song@kernel.org
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This is similar to modify_ftrace_direct_multi, but does not acquire
direct_mutex. This is useful when direct_mutex is already locked by the
user.
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/bpf/20220720002126.803253-2-song@kernel.org
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git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu
Pull RCU fix from Paul McKenney:
"This contains a pair of commits that fix 282d8998e997 ("srcu: Prevent
expedited GPs and blocking readers from consuming CPU"), which was
itself a fix to an SRCU expedited grace-period problem that could
prevent kernel live patching (KLP) from completing.
That SRCU fix for KLP introduced large (as in minutes) boot-time
delays to embedded Linux kernels running on qemu/KVM. These delays
were due to the emulation of certain MMIO operations controlling
memory layout, which were emulated with one expedited grace period per
access. Common configurations required thousands of boot-time MMIO
accesses, and thus thousands of boot-time expedited SRCU grace
periods.
In these configurations, the occasional sleeps that allowed KLP to
proceed caused excessive boot delays. These commits preserve enough
sleeps to permit KLP to proceed, but few enough that the virtual
embedded kernels still boot reasonably quickly.
This represents a regression introduced in the v5.19 merge window, and
the bug is causing significant inconvenience"
* tag 'rcu-urgent.2022.07.21a' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu:
srcu: Make expedited RCU grace periods block even less frequently
srcu: Block less aggressively for expedited grace periods
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Add a .kunitconfig file, which provides a default, working config for
running the KCSAN tests. Note that it needs to run on an SMP machine, so
to run under kunit_tool, the --qemu_args option should be used (on a
supported architecture, like x86_64). For example:
./tools/testing/kunit/kunit.py run --arch=x86_64 --qemu_args='-smp 8'
--kunitconfig=kernel/kcsan
Signed-off-by: David Gow <davidgow@google.com>
Reviewed-by: Marco Elver <elver@google.com>
Acked-by: Brendan Higgins <brendanhiggins@google.com>
Tested-by: Daniel Latypov <dlatypov@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
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