When offlining and onlining CPUs the overall reported idle and iowait
times as reported by /proc/stat jump backward and forward:
cpu 132 0 176 225249 47 6 6 21 0 0
cpu0 80 0 115 112575 33 3 4 18 0 0
cpu1 52 0 60 112673 13 3 1 2 0 0
cpu 133 0 177 226681 47 6 6 21 0 0
cpu0 80 0 116 113387 33 3 4 18 0 0
cpu 133 0 178 114431 33 6 6 21 0 0 <---- jump backward
cpu0 80 0 116 114247 33 3 4 18 0 0
cpu1 52 0 61 183 0 3 1 2 0 0 <---- idle + iowait start with 0
cpu 133 0 178 228956 47 6 6 21 0 0 <---- jump forward
cpu0 81 0 117 114929 33 3 4 18 0 0
Reason for this is that get_idle_time() in fs/proc/stat.c has different
sources for both values depending on if a CPU is online or offline:
- if a CPU is online the values may be taken from its per cpu
tick_cpu_sched structure
- if a CPU is offline the values are taken from its per cpu cpustat
structure
The problem is that the per cpu tick_cpu_sched structure is set to zero on
CPU offline. See tick_cancel_sched_timer() in kernel/time/tick-sched.c.
Therefore when a CPU is brought offline and online afterwards both its idle
and iowait sleeptime will be zero, causing a jump backward in total system
idle and iowait sleeptime. In a similar way if a CPU is then brought
offline again the total idle and iowait sleeptimes will jump forward.
It looks like this behavior was introduced with commit 4b0c0f294f
("tick: Cleanup NOHZ per cpu data on cpu down").
This was only noticed now on s390, since we switched to generic idle time
reporting with commit be76ea6144 ("s390/idle: remove arch_cpu_idle_time()
and corresponding code").
Fix this by preserving the values of idle_sleeptime and iowait_sleeptime
members of the per-cpu tick_sched structure on CPU hotplug.
Fixes: 4b0c0f294f ("tick: Cleanup NOHZ per cpu data on cpu down")
Reported-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20240115163555.1004144-1-hca@linux.ibm.com
When no timer is queued into an empty timer base, the next_expiry will not
be updated. It was originally calculated as
base->clk + NEXT_TIMER_MAX_DELTA
When the timer base stays empty long enough (> NEXT_TIMER_MAX_DELTA), the
next_expiry value of the empty base suggests that there is a timer pending
soon. This might be more a kind of a theoretical problem, but the fix
doesn't hurt.
Use only base->next_expiry value as nextevt when timers are
pending. Otherwise nextevt will be jiffies + NEXT_TIMER_MAX_DELTA. As all
information is in place, update base->next_expiry value of the empty timer
base as well.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-13-anna-maria@linutronix.de
To improve readability of the code, split base->idle calculation and
expires calculation into separate parts. While at it, update the comment
about timer base idle marking.
Thereby the following subtle change happens if the next event is just one
jiffy ahead and the tick was already stopped: Originally base->is_idle
remains true in this situation. Now base->is_idle turns to false. This may
spare an IPI if a timer is enqueued remotely to an idle CPU that is going
to tick on the next jiffy.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-12-anna-maria@linutronix.de
Forwarding timer base is done when the next expiry value is calculated and
when a new timer is enqueued. When the next expiry value is calculated the
jiffies value is already available and does not need to be reread a second
time.
Splitting out the forward timer base functionality to make it executable
via both contextes - those where jiffies are already known and those, where
jiffies need to be read.
No functional change.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-10-anna-maria@linutronix.de
The current check whether a forward of the timer base is required can be
simplified by using an already existing comparison function which is easier
to read. The related comment is outdated and was not updated when the check
changed in commit 36cd28a4cd ("timers: Lower base clock forwarding
threshold").
Use time_before_eq() for the check and replace the comment by copying the
comment from the same check inside get_next_timer_interrupt(). Move the
precious information of the outdated comment to the proper place in
__run_timers().
No functional change.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-9-anna-maria@linutronix.de
Deferrable timers do not prevent CPU from going idle and are not taken into
account on idle path. Sending an IPI to a remote CPU when a new first
deferrable timer was enqueued will wake up the remote CPU but nothing will
be done regarding the deferrable timers.
Drop IPI completely when a new first deferrable timer was enqueued.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-7-anna-maria@linutronix.de
For starting a timer, the timer is enqueued into a bucket of the timer
wheel. The bucket expiry is the defacto expiry of the timer but it is not
equal the timer expiry because of increasing granularity when bucket is in
a higher level of the wheel. To be able to figure out in a trace whether a
timer expired in time or not, the bucket expiry time is required as well.
Add bucket expiry time to the timer_start tracepoint and thereby simplify
the arguments.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-5-anna-maria@linutronix.de
When the next tick is in the past, the delta between basemono and the next
tick gets negativ. But the next tick should never be in the past. The
negative effect of a wrong next tick might be a stop of the tick and timers
might expire late.
To prevent expensive debugging when changing underlying code, add a
WARN_ON_ONCE into this code path. To prevent complete misbehaviour, also
reset next_tick to basemono in this case.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-4-anna-maria@linutronix.de
tick_nohz_stop_tick() contains the expires (u64 variable) and tick
(ktime_t) variable. In the beginning the value of expires is written to
tick. Afterwards none of the variables is changed. They are only used for
checks.
Drop the not required variable tick and use always expires instead.
Signed-off-by: Anna-Maria Behnsen <anna-maria@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Frederic Weisbecker <frederic@kernel.org>
Link: https://lore.kernel.org/r/20231201092654.34614-3-anna-maria@linutronix.de
This function is defined globally in clocksource.c and used conditionally
in clockevent.c, which the declaration hidden when clockevent support
is disabled. This causes a harmless warning in the definition:
kernel/time/clocksource.c:1324:9: warning: no previous prototype for 'sysfs_get_uname' [-Wmissing-prototypes]
1324 | ssize_t sysfs_get_uname(const char *buf, char *dst, size_t cnt)
Move the declaration out of the #ifdef so it is always visible.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20231108125843.3806765-5-arnd@kernel.org
Pull timer fix from Borislav Petkov:
- Do the push of pending hrtimers away from a CPU which is being
offlined earlier in the offlining process in order to prevent a
deadlock
* tag 'timers_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
hrtimers: Push pending hrtimers away from outgoing CPU earlier
Pull scheduler fixes from Borislav Petkov:
- Fix virtual runtime calculation when recomputing a sched entity's
weights
- Fix wrongly rejected unprivileged poll requests to the cgroup psi
pressure files
- Make sure the load balancing is done by only one CPU
* tag 'sched_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/fair: Fix the decision for load balance
sched: psi: fix unprivileged polling against cgroups
sched/eevdf: Fix vruntime adjustment on reweight
Pull locking fix from Borislav Petkov:
- Fix a hardcoded futex flags case which lead to one robust futex test
failure
* tag 'locking_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
futex: Fix hardcoded flags
Pull perf fix from Borislav Petkov:
- Make sure the context refcount is transferred too when migrating perf
events
* tag 'perf_urgent_for_v6.7_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/core: Fix cpuctx refcounting
Pull parisc fixes from Helge Deller:
"On parisc we still sometimes need writeable stacks, e.g. if programs
aren't compiled with gcc-14. To avoid issues with the upcoming
systemd-254 we therefore have to disable prctl(PR_SET_MDWE) for now
(for parisc only).
The other two patches are minor: a bugfix for the soft power-off on
qemu with 64-bit kernel and prefer strscpy() over strlcpy():
- Fix power soft-off on qemu
- Disable prctl(PR_SET_MDWE) since parisc sometimes still needs
writeable stacks
- Use strscpy instead of strlcpy in show_cpuinfo()"
* tag 'parisc-for-6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux:
prctl: Disable prctl(PR_SET_MDWE) on parisc
parisc/power: Fix power soft-off when running on qemu
parisc: Replace strlcpy() with strscpy()
Pull audit fix from Paul Moore:
"One small audit patch to convert a WARN_ON_ONCE() into a normal
conditional to avoid scary looking console warnings when eBPF code
generates audit records from unexpected places"
* tag 'audit-pr-20231116' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit:
audit: don't WARN_ON_ONCE(!current->mm) in audit_exe_compare()
Pull networking fixes from Paolo Abeni:
"Including fixes from BPF and netfilter.
Current release - regressions:
- core: fix undefined behavior in netdev name allocation
- bpf: do not allocate percpu memory at init stage
- netfilter: nf_tables: split async and sync catchall in two
functions
- mptcp: fix possible NULL pointer dereference on close
Current release - new code bugs:
- eth: ice: dpll: fix initial lock status of dpll
Previous releases - regressions:
- bpf: fix precision backtracking instruction iteration
- af_unix: fix use-after-free in unix_stream_read_actor()
- tipc: fix kernel-infoleak due to uninitialized TLV value
- eth: bonding: stop the device in bond_setup_by_slave()
- eth: mlx5:
- fix double free of encap_header
- avoid referencing skb after free-ing in drop path
- eth: hns3: fix VF reset
- eth: mvneta: fix calls to page_pool_get_stats
Previous releases - always broken:
- core: set SOCK_RCU_FREE before inserting socket into hashtable
- bpf: fix control-flow graph checking in privileged mode
- eth: ppp: limit MRU to 64K
- eth: stmmac: avoid rx queue overrun
- eth: icssg-prueth: fix error cleanup on failing initialization
- eth: hns3: fix out-of-bounds access may occur when coalesce info is
read via debugfs
- eth: cortina: handle large frames
Misc:
- selftests: gso: support CONFIG_MAX_SKB_FRAGS up to 45"
* tag 'net-6.7-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (78 commits)
macvlan: Don't propagate promisc change to lower dev in passthru
net: sched: do not offload flows with a helper in act_ct
net/mlx5e: Check return value of snprintf writing to fw_version buffer for representors
net/mlx5e: Check return value of snprintf writing to fw_version buffer
net/mlx5e: Reduce the size of icosq_str
net/mlx5: Increase size of irq name buffer
net/mlx5e: Update doorbell for port timestamping CQ before the software counter
net/mlx5e: Track xmit submission to PTP WQ after populating metadata map
net/mlx5e: Avoid referencing skb after free-ing in drop path of mlx5e_sq_xmit_wqe
net/mlx5e: Don't modify the peer sent-to-vport rules for IPSec offload
net/mlx5e: Fix pedit endianness
net/mlx5e: fix double free of encap_header in update funcs
net/mlx5e: fix double free of encap_header
net/mlx5: Decouple PHC .adjtime and .adjphase implementations
net/mlx5: DR, Allow old devices to use multi destination FTE
net/mlx5: Free used cpus mask when an IRQ is released
Revert "net/mlx5: DR, Supporting inline WQE when possible"
bpf: Do not allocate percpu memory at init stage
net: Fix undefined behavior in netdev name allocation
dt-bindings: net: ethernet-controller: Fix formatting error
...
Kirill Shutemov reported significant percpu memory consumption increase after
booting in 288-cpu VM ([1]) due to commit 41a5db8d81 ("bpf: Add support for
non-fix-size percpu mem allocation"). The percpu memory consumption is
increased from 111MB to 969MB. The number is from /proc/meminfo.
I tried to reproduce the issue with my local VM which at most supports upto
255 cpus. With 252 cpus, without the above commit, the percpu memory
consumption immediately after boot is 57MB while with the above commit the
percpu memory consumption is 231MB.
This is not good since so far percpu memory from bpf memory allocator is not
widely used yet. Let us change pre-allocation in init stage to on-demand
allocation when verifier detects there is a need of percpu memory for bpf
program. With this change, percpu memory consumption after boot can be reduced
signicantly.
[1] https://lore.kernel.org/lkml/20231109154934.4saimljtqx625l3v@box.shutemov.name/
Fixes: 41a5db8d81 ("bpf: Add support for non-fix-size percpu mem allocation")
Reported-and-tested-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20231111013928.948838-1-yonghong.song@linux.dev
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
eBPF can end up calling into the audit code from some odd places, and
some of these places don't have @current set properly so we end up
tripping the `WARN_ON_ONCE(!current->mm)` near the top of
`audit_exe_compare()`. While the basic `!current->mm` check is good,
the `WARN_ON_ONCE()` results in some scary console messages so let's
drop that and just do the regular `!current->mm` check to avoid
problems.
Cc: <stable@vger.kernel.org>
Fixes: 47846d5134 ("audit: don't take task_lock() in audit_exe_compare() code path")
Reported-by: Artem Savkov <asavkov@redhat.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
should_we_balance is called for the decision to do load-balancing.
When sched ticks invoke this function, only one CPU should return
true. However, in the current code, two CPUs can return true. The
following situation, where b means busy and i means idle, is an
example, because CPU 0 and CPU 2 return true.
[0, 1] [2, 3]
b b i b
This fix checks if there exists an idle CPU with busy sibling(s)
after looking for a CPU on an idle core. If some idle CPUs with busy
siblings are found, just the first one should do load-balancing.
Fixes: b1bfeab9b0 ("sched/fair: Consider the idle state of the whole core for load balance")
Signed-off-by: Keisuke Nishimura <keisuke.nishimura@inria.fr>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Reviewed-by: Shrikanth Hegde <sshegde@linux.vnet.ibm.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://lkml.kernel.org/r/20231031133821.1570861-1-keisuke.nishimura@inria.fr
519fabc7aa ("psi: remove 500ms min window size limitation for
triggers") breaks unprivileged psi polling on cgroups.
Historically, we had a privilege check for polling in the open() of a
pressure file in /proc, but were erroneously missing it for the open()
of cgroup pressure files.
When unprivileged polling was introduced in d82caa2735 ("sched/psi:
Allow unprivileged polling of N*2s period"), it needed to filter
privileges depending on the exact polling parameters, and as such
moved the CAP_SYS_RESOURCE check from the proc open() callback to
psi_trigger_create(). Both the proc files as well as cgroup files go
through this during write(). This implicitly added the missing check
for privileges required for HT polling for cgroups.
When 519fabc7aa ("psi: remove 500ms min window size limitation for
triggers") followed right after to remove further restrictions on the
RT polling window, it incorrectly assumed the cgroup privilege check
was still missing and added it to the cgroup open(), mirroring what we
used to do for proc files in the past.
As a result, unprivileged poll requests that would be supported now
get rejected when opening the cgroup pressure file for writing.
Remove the cgroup open() check. psi_trigger_create() handles it.
Fixes: 519fabc7aa ("psi: remove 500ms min window size limitation for triggers")
Reported-by: Luca Boccassi <bluca@debian.org>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Luca Boccassi <bluca@debian.org>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: stable@vger.kernel.org # 6.5+
Link: https://lore.kernel.org/r/20231026164114.2488682-1-hannes@cmpxchg.org
vruntime of the (on_rq && !0-lag) entity needs to be adjusted when
it gets re-weighted, and the calculations can be simplified based
on the fact that re-weight won't change the w-average of all the
entities. Please check the proofs in comments.
But adjusting vruntime can also cause position change in RB-tree
hence require re-queue to fix up which might be costly. This might
be avoided by deferring adjustment to the time the entity actually
leaves tree (dequeue/pick), but that will negatively affect task
selection and probably not good enough either.
Fixes: 147f3efaa2 ("sched/fair: Implement an EEVDF-like scheduling policy")
Signed-off-by: Abel Wu <wuyun.abel@bytedance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20231107090510.71322-2-wuyun.abel@bytedance.com
2b8272ff4a ("cpu/hotplug: Prevent self deadlock on CPU hot-unplug")
solved the straight forward CPU hotplug deadlock vs. the scheduler
bandwidth timer. Yu discovered a more involved variant where a task which
has a bandwidth timer started on the outgoing CPU holds a lock and then
gets throttled. If the lock required by one of the CPU hotplug callbacks
the hotplug operation deadlocks because the unthrottling timer event is not
handled on the dying CPU and can only be recovered once the control CPU
reaches the hotplug state which pulls the pending hrtimers from the dead
CPU.
Solve this by pushing the hrtimers away from the dying CPU in the dying
callbacks. Nothing can queue a hrtimer on the dying CPU at that point because
all other CPUs spin in stop_machine() with interrupts disabled and once the
operation is finished the CPU is marked offline.
Reported-by: Yu Liao <liaoyu15@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Liu Tie <liutie4@huawei.com>
Link: https://lore.kernel.org/r/87a5rphara.ffs@tglx
Pull probes fixes from Masami Hiramatsu:
- Documentation update: Add a note about argument and return value
fetching is the best effort because it depends on the type.
- objpool: Fix to make internal global variables static in
test_objpool.c.
- kprobes: Unify kprobes_exceptions_nofify() prototypes. There are the
same prototypes in asm/kprobes.h for some architectures, but some of
them are missing the prototype and it causes a warning. So move the
prototype into linux/kprobes.h.
- tracing: Fix to check the tracepoint event and return event at
parsing stage. The tracepoint event doesn't support %return but if
$retval exists, it will be converted to %return silently. This finds
that case and rejects it.
- tracing: Fix the order of the descriptions about the parameters of
__kprobe_event_gen_cmd_start() to be consistent with the argument
list of the function.
* tag 'probes-fixes-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
tracing/kprobes: Fix the order of argument descriptions
tracing: fprobe-event: Fix to check tracepoint event and return
kprobes: unify kprobes_exceptions_nofify() prototypes
lib: test_objpool: make global variables static
Documentation: tracing: Add a note about argument and retval access
Pull dma-mapping fixes from Christoph Hellwig:
- don't leave pages decrypted for DMA in encrypted memory setups linger
around on failure (Petr Tesarik)
- fix an out of bounds access in the new dynamic swiotlb code (Petr
Tesarik)
- fix dma_addressing_limited for systems with weird physical memory
layouts (Jia He)
* tag 'dma-mapping-6.7-2023-11-10' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: fix out-of-bounds TLB allocations with CONFIG_SWIOTLB_DYNAMIC
dma-mapping: fix dma_addressing_limited() if dma_range_map can't cover all system RAM
dma-mapping: move dma_addressing_limited() out of line
swiotlb: do not free decrypted pages if dynamic
Fix to check the tracepoint event is not valid with $retval.
The commit 08c9306fc2 ("tracing/fprobe-event: Assume fprobe is
a return event by $retval") introduced automatic return probe
conversion with $retval. But since tracepoint event does not
support return probe, $retval is not acceptable.
Without this fix, ftracetest, tprobe_syntax_errors.tc fails;
[22] Tracepoint probe event parser error log check [FAIL]
----
# tail 22-tprobe_syntax_errors.tc-log.mRKroL
+ ftrace_errlog_check trace_fprobe t kfree ^$retval dynamic_events
+ printf %s t kfree
+ wc -c
+ pos=8
+ printf %s t kfree ^$retval
+ tr -d ^
+ command=t kfree $retval
+ echo Test command: t kfree $retval
Test command: t kfree $retval
+ echo
----
So 't kfree $retval' should fail (tracepoint doesn't support
return probe) but passed it.
Link: https://lore.kernel.org/all/169944555933.45057.12831706585287704173.stgit@devnote2/
Fixes: 08c9306fc2 ("tracing/fprobe-event: Assume fprobe is a return event by $retval")
Cc: stable@vger.kernel.org
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
When BPF program is verified in privileged mode, BPF verifier allows
bounded loops. This means that from CFG point of view there are
definitely some back-edges. Original commit adjusted check_cfg() logic
to not detect back-edges in control flow graph if they are resulting
from conditional jumps, which the idea that subsequent full BPF
verification process will determine whether such loops are bounded or
not, and either accept or reject the BPF program. At least that's my
reading of the intent.
Unfortunately, the implementation of this idea doesn't work correctly in
all possible situations. Conditional jump might not result in immediate
back-edge, but just a few unconditional instructions later we can arrive
at back-edge. In such situations check_cfg() would reject BPF program
even in privileged mode, despite it might be bounded loop. Next patch
adds one simple program demonstrating such scenario.
To keep things simple, instead of trying to detect back edges in
privileged mode, just assume every back edge is valid and let subsequent
BPF verification prove or reject bounded loops.
Note a few test changes. For unknown reason, we have a few tests that
are specified to detect a back-edge in a privileged mode, but looking at
their code it seems like the right outcome is passing check_cfg() and
letting subsequent verification to make a decision about bounded or not
bounded looping.
Bounded recursion case is also interesting. The example should pass, as
recursion is limited to just a few levels and so we never reach maximum
number of nested frames and never exhaust maximum stack depth. But the
way that max stack depth logic works today it falsely detects this as
exceeding max nested frame count. This patch series doesn't attempt to
fix this orthogonal problem, so we just adjust expected verifier failure.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Fixes: 2589726d12 ("bpf: introduce bounded loops")
Reported-by: Hao Sun <sunhao.th@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231110061412.2995786-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Fix an edge case in __mark_chain_precision() which prematurely stops
backtracking instructions in a state if it happens that state's first
and last instruction indexes are the same. This situations doesn't
necessarily mean that there were no instructions simulated in a state,
but rather that we starting from the instruction, jumped around a bit,
and then ended up at the same instruction before checkpointing or
marking precision.
To distinguish between these two possible situations, we need to consult
jump history. If it's empty or contain a single record "bridging" parent
state and first instruction of processed state, then we indeed
backtracked all instructions in this state. But if history is not empty,
we are definitely not done yet.
Move this logic inside get_prev_insn_idx() to contain it more nicely.
Use -ENOENT return code to denote "we are out of instructions"
situation.
This bug was exposed by verifier_loop1.c's bounded_recursion subtest, once
the next fix in this patch set is applied.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Fixes: b5dc0163d8 ("bpf: precise scalar_value tracking")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231110002638.4168352-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
ldimm64 instructions are 16-byte long, and so have to be handled
appropriately in check_cfg(), just like the rest of BPF verifier does.
This has implications in three places:
- when determining next instruction for non-jump instructions;
- when determining next instruction for callback address ldimm64
instructions (in visit_func_call_insn());
- when checking for unreachable instructions, where second half of
ldimm64 is expected to be unreachable;
We take this also as an opportunity to report jump into the middle of
ldimm64. And adjust few test_verifier tests accordingly.
Acked-by: Eduard Zingerman <eddyz87@gmail.com>
Reported-by: Hao Sun <sunhao.th@gmail.com>
Fixes: 475fb78fbf ("bpf: verifier (add branch/goto checks)")
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20231110002638.4168352-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Pull networking fixes from Jakub Kicinski:
"Including fixes from netfilter and bpf.
Current release - regressions:
- sched: fix SKB_NOT_DROPPED_YET splat under debug config
Current release - new code bugs:
- tcp:
- fix usec timestamps with TCP fastopen
- fix possible out-of-bounds reads in tcp_hash_fail()
- fix SYN option room calculation for TCP-AO
- tcp_sigpool: fix some off by one bugs
- bpf: fix compilation error without CGROUPS
- ptp:
- ptp_read() should not release queue
- fix tsevqs corruption
Previous releases - regressions:
- llc: verify mac len before reading mac header
Previous releases - always broken:
- bpf:
- fix check_stack_write_fixed_off() to correctly spill imm
- fix precision tracking for BPF_ALU | BPF_TO_BE | BPF_END
- check map->usercnt after timer->timer is assigned
- dsa: lan9303: consequently nested-lock physical MDIO
- dccp/tcp: call security_inet_conn_request() after setting IP addr
- tg3: fix the TX ring stall due to incorrect full ring handling
- phylink: initialize carrier state at creation
- ice: fix direction of VF rules in switchdev mode
Misc:
- fill in a bunch of missing MODULE_DESCRIPTION()s, more to come"
* tag 'net-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (84 commits)
net: ti: icss-iep: fix setting counter value
ptp: fix corrupted list in ptp_open
ptp: ptp_read should not release queue
net_sched: sch_fq: better validate TCA_FQ_WEIGHTS and TCA_FQ_PRIOMAP
net: kcm: fill in MODULE_DESCRIPTION()
net/sched: act_ct: Always fill offloading tuple iifidx
netfilter: nat: fix ipv6 nat redirect with mapped and scoped addresses
netfilter: xt_recent: fix (increase) ipv6 literal buffer length
ipvs: add missing module descriptions
netfilter: nf_tables: remove catchall element in GC sync path
netfilter: add missing module descriptions
drivers/net/ppp: use standard array-copy-function
net: enetc: shorten enetc_setup_xdp_prog() error message to fit NETLINK_MAX_FMTMSG_LEN
virtio/vsock: Fix uninit-value in virtio_transport_recv_pkt()
r8169: respect userspace disabling IFF_MULTICAST
selftests/bpf: get trusted cgrp from bpf_iter__cgroup directly
bpf: Let verifier consider {task,cgroup} is trusted in bpf_iter_reg
net: phylink: initialize carrier state at creation
test/vsock: add dobule bind connect test
test/vsock: refactor vsock_accept
...
Pull RCU fixes from Frederic Weisbecker:
- Fix a lock inversion between scheduler and RCU introduced in
v6.2-rc4. The scenario could trigger on any user of RCU_NOCB
(mostly Android but also nohz_full)
- Fix PF_IDLE semantic changes introduced in v6.6-rc3 breaking
some RCU-Tasks and RCU-Tasks-Trace expectations as to what
exactly is an idle task. This resulted in potential spurious
stalls and warnings.
* tag 'rcu-fixes-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks:
rcu/tasks-trace: Handle new PF_IDLE semantics
rcu/tasks: Handle new PF_IDLE semantics
rcu: Introduce rcu_cpu_online()
rcu: Break rcu_node_0 --> &rq->__lock order
Pull kgdb updates from Daniel Thompson:
"Just two patches for you this time!
- During a panic, flush the console before entering kgdb.
This makes things a little easier to comprehend, especially if an
NMI backtrace was triggered on all CPUs just before we enter the
panic routines
- Correcting a couple of misleading (a.k.a. plain wrong) comments"
* tag 'kgdb-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/danielt/linux:
kdb: Corrects comment for kdballocenv
kgdb: Flush console before entering kgdb on panic
BTF_TYPE_SAFE_TRUSTED(struct bpf_iter__task) in verifier.c wanted to
teach BPF verifier that bpf_iter__task -> task is a trusted ptr. But it
doesn't work well.
The reason is, bpf_iter__task -> task would go through btf_ctx_access()
which enforces the reg_type of 'task' is ctx_arg_info->reg_type, and in
task_iter.c, we actually explicitly declare that the
ctx_arg_info->reg_type is PTR_TO_BTF_ID_OR_NULL.
Actually we have a previous case like this[1] where PTR_TRUSTED is added to
the arg flag for map_iter.
This patch sets ctx_arg_info->reg_type is PTR_TO_BTF_ID_OR_NULL |
PTR_TRUSTED in task_reg_info.
Similarly, bpf_cgroup_reg_info -> cgroup is also PTR_TRUSTED since we are
under the protection of cgroup_mutex and we would check cgroup_is_dead()
in __cgroup_iter_seq_show().
This patch is to improve the user experience of the newly introduced
bpf_iter_css_task kfunc before hitting the mainline. The Fixes tag is
pointing to the commit introduced the bpf_iter_css_task kfunc.
Link[1]:https://lore.kernel.org/all/20230706133932.45883-3-aspsk@isovalent.com/
Fixes: 9c66dc94b6 ("bpf: Introduce css_task open-coded iterator kfuncs")
Signed-off-by: Chuyi Zhou <zhouchuyi@bytedance.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231107132204.912120-2-zhouchuyi@bytedance.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
There is an unusual case that the range map covers right up to the top
of system RAM, but leaves a hole somewhere lower down. Then it prevents
the nvme device dma mapping in the checking path of phys_to_dma() and
causes the hangs at boot.
E.g. On an Armv8 Ampere server, the dsdt ACPI table is:
Method (_DMA, 0, Serialized) // _DMA: Direct Memory Access
{
Name (RBUF, ResourceTemplate ()
{
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x0000000000000000, // Range Minimum
0x00000000FFFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x0000000100000000, // Length
,, , AddressRangeMemory, TypeStatic)
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x0000006010200000, // Range Minimum
0x000000602FFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x000000001FE00000, // Length
,, , AddressRangeMemory, TypeStatic)
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x00000060F0000000, // Range Minimum
0x00000060FFFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x0000000010000000, // Length
,, , AddressRangeMemory, TypeStatic)
QWordMemory (ResourceConsumer, PosDecode, MinFixed,
MaxFixed, Cacheable, ReadWrite,
0x0000000000000000, // Granularity
0x0000007000000000, // Range Minimum
0x000003FFFFFFFFFF, // Range Maximum
0x0000000000000000, // Translation Offset
0x0000039000000000, // Length
,, , AddressRangeMemory, TypeStatic)
})
But the System RAM ranges are:
cat /proc/iomem |grep -i ram
90000000-91ffffff : System RAM
92900000-fffbffff : System RAM
880000000-fffffffff : System RAM
8800000000-bff5990fff : System RAM
bff59d0000-bff5a4ffff : System RAM
bff8000000-bfffffffff : System RAM
So some RAM ranges are out of dma_range_map.
Fix it by checking whether each of the system RAM resources can be
properly encompassed within the dma_range_map.
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This patch moves dma_addressing_limited() out of line, serving as a
preliminary step to prevent the introduction of a new publicly accessible
low-level helper when validating whether all system RAM is mapped within
the DMA mapping range.
Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jia He <justin.he@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Pull tty and serial updates from Greg KH:
"Here is the big set of tty/serial driver changes for 6.7-rc1. Included
in here are:
- console/vgacon cleanups and removals from Arnd
- tty core and n_tty cleanups from Jiri
- lots of 8250 driver updates and cleanups
- sc16is7xx serial driver updates
- dt binding updates
- first set of port lock wrapers from Thomas for the printk fixes
coming in future releases
- other small serial and tty core cleanups and updates
All of these have been in linux-next for a while with no reported
issues"
* tag 'tty-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (193 commits)
serdev: Replace custom code with device_match_acpi_handle()
serdev: Simplify devm_serdev_device_open() function
serdev: Make use of device_set_node()
tty: n_gsm: add copyright Siemens Mobility GmbH
tty: n_gsm: fix race condition in status line change on dead connections
serial: core: Fix runtime PM handling for pending tx
vgacon: fix mips/sibyte build regression
dt-bindings: serial: drop unsupported samsung bindings
tty: serial: samsung: drop earlycon support for unsupported platforms
tty: 8250: Add note for PX-835
tty: 8250: Fix IS-200 PCI ID comment
tty: 8250: Add Brainboxes Oxford Semiconductor-based quirks
tty: 8250: Add support for Intashield IX cards
tty: 8250: Add support for additional Brainboxes PX cards
tty: 8250: Fix up PX-803/PX-857
tty: 8250: Fix port count of PX-257
tty: 8250: Add support for Intashield IS-100
tty: 8250: Add support for Brainboxes UP cards
tty: 8250: Add support for additional Brainboxes UC cards
tty: 8250: Remove UC-257 and UC-431
...
Pull driver core updates from Greg KH:
"Here is the set of driver core updates for 6.7-rc1. Nothing major in
here at all, just a small number of changes including:
- minor cleanups and updates from Andy Shevchenko
- __counted_by addition
- firmware_loader update for aborting loads cleaner
- other minor changes, details in the shortlog
- documentation update
All of these have been in linux-next for a while with no reported
issues"
* tag 'driver-core-6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (21 commits)
firmware_loader: Abort all upcoming firmware load request once reboot triggered
firmware_loader: Refactor kill_pending_fw_fallback_reqs()
Documentation: security-bugs.rst: linux-distros relaxed their rules
driver core: Release all resources during unbind before updating device links
driver core: class: remove boilerplate code
driver core: platform: Annotate struct irq_affinity_devres with __counted_by
resource: Constify resource crosscheck APIs
resource: Unify next_resource() and next_resource_skip_children()
resource: Reuse for_each_resource() macro
PCI: Implement custom llseek for sysfs resource entries
kernfs: sysfs: support custom llseek method for sysfs entries
debugfs: Fix __rcu type comparison warning
device property: Replace custom implementation of COUNT_ARGS()
drivers: base: test: Make property entry API test modular
driver core: Add missing parameter description to __fwnode_link_add()
device property: Clarify usage scope of some struct fwnode_handle members
devres: rename the first parameter of devm_add_action(_or_reset)
driver core: platform: Unify the firmware node type check
driver core: platform: Use temporary variable in platform_device_add()
driver core: platform: Refactor error path in a couple places
...
Pull tracing updates from Steven Rostedt:
- Remove eventfs_file descriptor
This is the biggest change, and the second part of making eventfs
create its files dynamically.
In 6.6 the first part was added, and that maintained a one to one
mapping between eventfs meta descriptors and the directories and file
inodes and dentries that were dynamically created. The directories
were represented by a eventfs_inode and the files were represented by
a eventfs_file.
In v6.7 the eventfs_file is removed. As all events have the same
directory make up (sched_switch has an "enable", "id", "format", etc
files), the handing of what files are underneath each leaf eventfs
directory is moved back to the tracing subsystem via a callback.
When an event is added to the eventfs, it registers an array of
evenfs_entry's. These hold the names of the files and the callbacks
to call when the file is referenced. The callback gets the name so
that the same callback may be used by multiple files. The callback
then supplies the filesystem_operations structure needed to create
this file.
This has brought the memory footprint of creating multiple eventfs
instances down by 2 megs each!
- User events now has persistent events that are not associated to a
single processes. These are privileged events that hang around even
if no process is attached to them
- Clean up of seq_buf
There's talk about using seq_buf more to replace strscpy() and
friends. But this also requires some minor modifications of seq_buf
to be able to do this
- Expand instance ring buffers individually
Currently if boot up creates an instance, and a trace event is
enabled on that instance, the ring buffer for that instance and the
top level ring buffer are expanded (1.4 MB per CPU). This wastes
memory as this happens when nothing is using the top level instance
- Other minor clean ups and fixes
* tag 'trace-v6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (34 commits)
seq_buf: Export seq_buf_puts()
seq_buf: Export seq_buf_putc()
eventfs: Use simple_recursive_removal() to clean up dentries
eventfs: Remove special processing of dput() of events directory
eventfs: Delete eventfs_inode when the last dentry is freed
eventfs: Hold eventfs_mutex when calling callback functions
eventfs: Save ownership and mode
eventfs: Test for ei->is_freed when accessing ei->dentry
eventfs: Have a free_ei() that just frees the eventfs_inode
eventfs: Remove "is_freed" union with rcu head
eventfs: Fix kerneldoc of eventfs_remove_rec()
tracing: Have the user copy of synthetic event address use correct context
eventfs: Remove extra dget() in eventfs_create_events_dir()
tracing: Have trace_event_file have ref counters
seq_buf: Introduce DECLARE_SEQ_BUF and seq_buf_str()
eventfs: Fix typo in eventfs_inode union comment
eventfs: Fix WARN_ON() in create_file_dentry()
powerpc: Remove initialisation of readpos
tracing/histograms: Simplify last_cmd_set()
seq_buf: fix a misleading comment
...
Pull printk updates from Petr Mladek:
- Another preparation step for introducing printk kthreads. The main
piece is a per-console lock with several features:
- Support three priorities: normal, emergency, and panic. They will
be defined by a context where the lock is taken. A context with a
higher priority is allowed to take over the lock from a context
with a lower one.
The plan is to use the emergency context for Oops and WARN()
messages, and also by watchdogs.
The panic() context will be used on panic CPU.
- The owner might enter/exit regions where it is not safe to take
over the lock. It allows the take over the lock a safe way in the
middle of a message.
For example, serial drivers emit characters one by one. And the
serial port is in a safe state in between.
Only the final console_flush_in_panic() will be allowed to take
over the lock even in the unsafe state (last chance, pray, and
hope).
- A higher priority context might busy wait with a timeout. The
current owner is informed about the waiter and releases the lock
on exit from the unsafe state.
- The new lock is safe even in atomic contexts, including NMI.
Another change is a safe manipulation of per-console sequence number
counter under the new lock.
- simple_strntoull() micro-optimization
- Reduce pr_flush() pooling time.
- Calm down false warning about possible buffer invalid access to
console buffers when CONFIG_PRINTK is disabled.
[ .. and Thomas Gleixner wants to point out that while several of the
commits are attributed to him, he only authored the early versions of
said commits, and that John Ogness and Petr Mladek have been the ones
who sorted out the details and really should be those who get the
credit - Linus ]
* tag 'printk-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux:
vsprintf: uninline simple_strntoull(), reorder arguments
printk: printk: Remove unnecessary statements＇len = 0;＇
printk: Reduce pr_flush() pooling time
printk: fix illegal pbufs access for !CONFIG_PRINTK
printk: nbcon: Allow drivers to mark unsafe regions and check state
printk: nbcon: Add emit function and callback function for atomic printing
printk: nbcon: Add sequence handling
printk: nbcon: Add ownership state functions
printk: nbcon: Add buffer management
printk: Make static printk buffers available to nbcon
printk: nbcon: Add acquire/release logic
printk: Add non-BKL (nbcon) console basic infrastructure
Pull livepatching update from Petr Mladek:
- Add missing newline character to avoid waiting for a continuous
message
* tag 'livepatching-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/livepatching/livepatching:
livepatch: Fix missing newline character in klp_resolve_symbols()
