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It turns out that udev under certain circumstances will concurrently try
to load the same modules over-and-over excessively. This isn't a kernel
bug, but it ends up affecting the kernel, to the point that under
certain circumstances we can fail to boot, because the kernel uses a lot
of memory to read all the module data all at once.
Note that it isn't a memory leak, it's just basically a thundering herd
problem happening at bootup with a lot of CPUs, with the worst cases
then being pretty bad.
Admittedly the worst situations are somewhat contrived: lots and lots of
CPUs, not a lot of memory, and KASAN enabled to make it all slower and
as such (unintentionally) exacerbate the problem.
Luis explains: [1]
"My best assessment of the situation is that each CPU in udev ends up
triggering a load of duplicate set of modules, not just one, but *a
lot*. Not sure what heuristics udev uses to load a set of modules per
CPU."
Petr Pavlu chimes in: [2]
"My understanding is that udev workers are forked. An initial kmod
context is created by the main udevd process but no sharing happens
after the fork. It means that the mentioned memory pool logic doesn't
really kick in.
Multiple parallel load requests come from multiple udev workers, for
instance, each handling an udev event for one CPU device and making
the exactly same requests as all others are doing at the same time.
The optimization idea would be to recognize these duplicate requests
at the udevd/kmod level and converge them"
Note that module loading has tried to mitigate this issue before, see
for example commit 064f4536d139 ("module: avoid allocation if module is
already present and ready"), which has a few ASCII graphs on memory use
due to this same issue.
However, while that noticed that the module was already loaded, and
exited with an error early before spending any more time on setting up
the module, it didn't handle the case of multiple concurrent module
loads all being active - but not complete - at the same time.
Yes, one of them will eventually win the race and finalize its copy, and
the others will then notice that the module already exists and error
out, but while this all happens, we have tons of unnecessary concurrent
work being done.
Again, the real fix is for udev to not do that (maybe it should use
threads instead of fork, and have actual shared data structures and not
cause duplicate work). That real fix is apparently not trivial.
But it turns out that the kernel already has a pretty good model for
dealing with concurrent access to the same file: the i_writecount of the
inode.
In fact, the module loading already indirectly uses 'i_writecount' ,
because 'kernel_file_read()' will in fact do
ret = deny_write_access(file);
if (ret)
return ret;
...
allow_write_access(file);
around the read of the file data. We do not allow concurrent writes to
the file, and return -ETXTBUSY if the file was open for writing at the
same time as the module data is loaded from it.
And the solution to the reader concurrency problem is to simply extend
this "no concurrent writers" logic to simply be "exclusive access".
Note that "exclusive" in this context isn't really some absolute thing:
it's only exclusion from writers and from other "special readers" that
do this writer denial. So we simply introduce a variation of that
"deny_write_access()" logic that not only denies write access, but also
requires that this is the _only_ such access that denies write access.
Which means that you can't start loading a module that is already being
loaded as a module by somebody else, or you will get the same -ETXTBSY
error that you would get if there were writers around.
[ It also means that you can't try to load a currently executing
executable as a module, for the same reason: executables do that same
"deny_write_access()" thing, and that's obviously where the whole
ETXTBSY logic traditionally came from.
This is not a problem for kernel modules, since the set of normal
executable files and kernel module files is entirely disjoint. ]
This new function is called "exclusive_deny_write_access()", and the
implementation is trivial, in that it's just an atomic decrement of
i_writecount if it was 0 before.
To use that new exclusivity check, all we then do is wrap the module
loading with that exclusive_deny_write_access()() / allow_write_access()
pair. The actual patch is a bit bigger than that, because we want to
surround not just the "load file data" part, but the whole module setup,
to get maximum exclusion.
So this ends up splitting up "finit_module()" into a few helper
functions to make it all very clear and legible.
In Luis' test-case (bringing up 255 vcpu's in a virtual machine [3]),
the "wasted vmalloc" space (ie module data read into a vmalloc'ed area
in order to be loaded as a module, but then discarded because somebody
else loaded the same module instead) dropped from 1.8GiB to 474kB. Yes,
that's gigabytes to kilobytes.
It doesn't drop completely to zero, because even with this change, you
can still end up having completely serial pointless module loads, where
one udev process has loaded a module fully (and thus the kernel has
released that exclusive lock on the module file), and then another udev
process tries to load the same module again.
So while we cannot fully get rid of the fundamental bug in user space,
we _can_ get rid of the excessive concurrent thundering herd effect.
A couple of final side notes on this all:
- This tweak only affects the "finit_module()" system call, which gives
the kernel a file descriptor with the module data.
You can also just feed the module data as raw data from user space
with "init_module()" (note the lack of 'f' at the beginning), and
obviously for that case we do _not_ have any "exclusive read" logic.
So if you absolutely want to do things wrong in user space, and try
to load the same module multiple times, and error out only later when
the kernel ends up saying "you can't load the same module name
twice", you can still do that.
And in fact, some distros will do exactly that, because they will
uncompress the kernel module data in user space before feeding it to
the kernel (mainly because they haven't started using the new kernel
side decompression yet).
So this is not some absolute "you can't do concurrent loads of the
same module". It's literally just a very simple heuristic that will
catch it early in case you try to load the exact same module file at
the same time, and in that case avoid a potentially nasty situation.
- There is another user of "deny_write_access()": the verity code that
enables fs-verity on a file (the FS_IOC_ENABLE_VERITY ioctl).
If you use fs-verity and you care about verifying the kernel modules
(which does make sense), you should do it *before* loading said
kernel module. That may sound obvious, but now the implementation
basically requires it. Because if you try to do it concurrently, the
kernel may refuse to load the module file that is being set up by the
fs-verity code.
- This all will obviously mean that if you insist on loading the same
module in parallel, only one module load will succeed, and the others
will return with an error.
That was true before too, but what is different is that the -ETXTBSY
error can be returned *before* the success case of another process
fully loading and instantiating the module.
Again, that might sound obvious, and it is indeed the whole point of
the whole change: we are much quicker to notice the whole "you're
already in the process of loading this module".
So it's very much intentional, but it does mean that if you just
spray the kernel with "finit_module()", and expect that the module is
immediately loaded afterwards without checking the return value, you
are doing something horribly horribly wrong.
I'd like to say that that would never happen, but the whole _reason_
for this commit is that udev is currently doing something horribly
horribly wrong, so ...
Link: https://lore.kernel.org/all/[email protected]/ [1]
Link: https://lore.kernel.org/all/[email protected]/ [2]
Link: https://lore.kernel.org/lkml/ZG%2Fa+nrt4%[email protected]/ [3]
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Lucas De Marchi <[email protected]>
Cc: Petr Pavlu <[email protected]>
Tested-by: Luis Chamberlain <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Pull networking fixes from Paolo Abeni:
"Including fixes from bluetooth and bpf.
Current release - regressions:
- net: fix skb leak in __skb_tstamp_tx()
- eth: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs
Current release - new code bugs:
- handshake:
- fix sock->file allocation
- fix handshake_dup() ref counting
- bluetooth:
- fix potential double free caused by hci_conn_unlink
- fix UAF in hci_conn_hash_flush
Previous releases - regressions:
- core: fix stack overflow when LRO is disabled for virtual
interfaces
- tls: fix strparser rx issues
- bpf:
- fix many sockmap/TCP related issues
- fix a memory leak in the LRU and LRU_PERCPU hash maps
- init the offload table earlier
- eth: mlx5e:
- do as little as possible in napi poll when budget is 0
- fix using eswitch mapping in nic mode
- fix deadlock in tc route query code
Previous releases - always broken:
- udplite: fix NULL pointer dereference in __sk_mem_raise_allocated()
- raw: fix output xfrm lookup wrt protocol
- smc: reset connection when trying to use SMCRv2 fails
- phy: mscc: enable VSC8501/2 RGMII RX clock
- eth: octeontx2-pf: fix TSOv6 offload
- eth: cdc_ncm: deal with too low values of dwNtbOutMaxSize"
* tag 'net-6.4-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (79 commits)
udplite: Fix NULL pointer dereference in __sk_mem_raise_allocated().
net: phy: mscc: enable VSC8501/2 RGMII RX clock
net: phy: mscc: remove unnecessary phydev locking
net: phy: mscc: add support for VSC8501
net: phy: mscc: add VSC8502 to MODULE_DEVICE_TABLE
net/handshake: Enable the SNI extension to work properly
net/handshake: Unpin sock->file if a handshake is cancelled
net/handshake: handshake_genl_notify() shouldn't ignore @flags
net/handshake: Fix uninitialized local variable
net/handshake: Fix handshake_dup() ref counting
net/handshake: Remove unneeded check from handshake_dup()
ipv6: Fix out-of-bounds access in ipv6_find_tlv()
net: ethernet: mtk_eth_soc: fix QoS on DSA MAC on non MTK_NETSYS_V2 SoCs
docs: netdev: document the existence of the mail bot
net: fix skb leak in __skb_tstamp_tx()
r8169: Use a raw_spinlock_t for the register locks.
page_pool: fix inconsistency for page_pool_ring_[un]lock()
bpf, sockmap: Test progs verifier error with latest clang
bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops
bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer
...
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https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf
Daniel Borkmann says:
====================
pull-request: bpf 2023-05-24
We've added 19 non-merge commits during the last 10 day(s) which contain
a total of 20 files changed, 738 insertions(+), 448 deletions(-).
The main changes are:
1) Batch of BPF sockmap fixes found when running against NGINX TCP tests,
from John Fastabend.
2) Fix a memleak in the LRU{,_PERCPU} hash map when bucket locking fails,
from Anton Protopopov.
3) Init the BPF offload table earlier than just late_initcall,
from Jakub Kicinski.
4) Fix ctx access mask generation for 32-bit narrow loads of 64-bit fields,
from Will Deacon.
5) Remove a now unsupported __fallthrough in BPF samples,
from Andrii Nakryiko.
6) Fix a typo in pkg-config call for building sign-file,
from Jeremy Sowden.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf, sockmap: Test progs verifier error with latest clang
bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops
bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer
bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0
bpf, sockmap: Build helper to create connected socket pair
bpf, sockmap: Pull socket helpers out of listen test for general use
bpf, sockmap: Incorrectly handling copied_seq
bpf, sockmap: Wake up polling after data copy
bpf, sockmap: TCP data stall on recv before accept
bpf, sockmap: Handle fin correctly
bpf, sockmap: Improved check for empty queue
bpf, sockmap: Reschedule is now done through backlog
bpf, sockmap: Convert schedule_work into delayed_work
bpf, sockmap: Pass skb ownership through read_skb
bpf: fix a memory leak in the LRU and LRU_PERCPU hash maps
bpf: Fix mask generation for 32-bit narrow loads of 64-bit fields
samples/bpf: Drop unnecessary fallthrough
bpf: netdev: init the offload table earlier
selftests/bpf: Fix pkg-config call building sign-file
====================
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
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Smatch warns:
kernel/module/stats.c:394 read_file_mod_stats()
warn: passing freed memory 'buf'
We are passing 'buf' to simple_read_from_buffer() after freeing it.
Fix this by changing the order of 'simple_read_from_buffer' and 'kfree'.
Fixes: df3e764d8e5c ("module: add debug stats to help identify memory pressure")
Signed-off-by: Harshit Mogalapalli <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
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The LRU and LRU_PERCPU maps allocate a new element on update before locking the
target hash table bucket. Right after that the maps try to lock the bucket.
If this fails, then maps return -EBUSY to the caller without releasing the
allocated element. This makes the element untracked: it doesn't belong to
either of free lists, and it doesn't belong to the hash table, so can't be
re-used; this eventually leads to the permanent -ENOMEM on LRU map updates,
which is unexpected. Fix this by returning the element to the local free list
if bucket locking fails.
Fixes: 20b6cc34ea74 ("bpf: Avoid hashtab deadlock with map_locked")
Signed-off-by: Anton Protopopov <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin KaFai Lau <[email protected]>
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A narrow load from a 64-bit context field results in a 64-bit load
followed potentially by a 64-bit right-shift and then a bitwise AND
operation to extract the relevant data.
In the case of a 32-bit access, an immediate mask of 0xffffffff is used
to construct a 64-bit BPP_AND operation which then sign-extends the mask
value and effectively acts as a glorified no-op. For example:
0: 61 10 00 00 00 00 00 00 r0 = *(u32 *)(r1 + 0)
results in the following code generation for a 64-bit field:
ldr x7, [x7] // 64-bit load
mov x10, #0xffffffffffffffff
and x7, x7, x10
Fix the mask generation so that narrow loads always perform a 32-bit AND
operation:
ldr x7, [x7] // 64-bit load
mov w10, #0xffffffff
and w7, w7, w10
Cc: Alexei Starovoitov <[email protected]>
Cc: Daniel Borkmann <[email protected]>
Cc: John Fastabend <[email protected]>
Cc: Krzesimir Nowak <[email protected]>
Cc: Andrey Ignatov <[email protected]>
Acked-by: Yonghong Song <[email protected]>
Fixes: 31fd85816dbe ("bpf: permits narrower load from bpf program context fields")
Signed-off-by: Will Deacon <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull probes fixes from Masami Hiramatsu:
- Initialize 'ret' local variables on fprobe_handler() to fix the
smatch warning. With this, fprobe function exit handler is not
working randomly.
- Fix to use preempt_enable/disable_notrace for rethook handler to
prevent recursive call of fprobe exit handler (which is based on
rethook)
- Fix recursive call issue on fprobe_kprobe_handler()
- Fix to detect recursive call on fprobe_exit_handler()
- Fix to make all arch-dependent rethook code notrace (the
arch-independent code is already notrace)"
* tag 'probes-fixes-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rethook, fprobe: do not trace rethook related functions
fprobe: add recursion detection in fprobe_exit_handler
fprobe: make fprobe_kprobe_handler recursion free
rethook: use preempt_{disable, enable}_notrace in rethook_trampoline_handler
tracing: fprobe: Initialize ret valiable to fix smatch error
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fprobe_hander and fprobe_kprobe_handler has guarded ftrace recursion
detection but fprobe_exit_handler has not, which possibly introduce
recursive calls if the fprobe exit callback calls any traceable
functions. Checking in fprobe_hander or fprobe_kprobe_handler
is not enough and misses this case.
So add recursion free guard the same way as fprobe_hander. Since
ftrace recursion check does not employ ip(s), so here use entry_ip and
entry_parent_ip the same as fprobe_handler.
Link: https://lore.kernel.org/all/[email protected]/
Fixes: 5b0ab78998e3 ("fprobe: Add exit_handler support")
Signed-off-by: Ze Gao <[email protected]>
Cc: [email protected]
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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Current implementation calls kprobe related functions before doing
ftrace recursion check in fprobe_kprobe_handler, which opens door
to kernel crash due to stack recursion if preempt_count_{add, sub}
is traceable in kprobe_busy_{begin, end}.
Things goes like this without this patch quoted from Steven:
"
fprobe_kprobe_handler() {
kprobe_busy_begin() {
preempt_disable() {
preempt_count_add() { <-- trace
fprobe_kprobe_handler() {
[ wash, rinse, repeat, CRASH!!! ]
"
By refactoring the common part out of fprobe_kprobe_handler and
fprobe_handler and call ftrace recursion detection at the very beginning,
the whole fprobe_kprobe_handler is free from recursion.
[ Fix the indentation of __fprobe_handler() parameters. ]
Link: https://lore.kernel.org/all/[email protected]/
Fixes: ab51e15d535e ("fprobe: Introduce FPROBE_FL_KPROBE_SHARED flag for fprobe")
Signed-off-by: Ze Gao <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Cc: [email protected]
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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This patch replaces preempt_{disable, enable} with its corresponding
notrace version in rethook_trampoline_handler so no worries about stack
recursion or overflow introduced by preempt_count_{add, sub} under
fprobe + rethook context.
Link: https://lore.kernel.org/all/[email protected]/
Fixes: 54ecbe6f1ed5 ("rethook: Add a generic return hook")
Signed-off-by: Ze Gao <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Cc: <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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The commit 39d954200bf6 ("fprobe: Skip exit_handler if entry_handler returns
!0") introduced a hidden dependency of 'ret' local variable in the
fprobe_handler(), Smatch warns the `ret` can be accessed without
initialization.
kernel/trace/fprobe.c:59 fprobe_handler()
error: uninitialized symbol 'ret'.
kernel/trace/fprobe.c
49 fpr->entry_ip = ip;
50 if (fp->entry_data_size)
51 entry_data = fpr->data;
52 }
53
54 if (fp->entry_handler)
55 ret = fp->entry_handler(fp, ip, ftrace_get_regs(fregs), entry_data);
ret is only initialized if there is an ->entry_handler
56
57 /* If entry_handler returns !0, nmissed is not counted. */
58 if (rh) {
rh is only true if there is an ->exit_handler. Presumably if you have
and ->exit_handler that means you also have a ->entry_handler but Smatch
is not smart enough to figure it out.
--> 59 if (ret)
^^^
Warning here.
60 rethook_recycle(rh);
61 else
62 rethook_hook(rh, ftrace_get_regs(fregs), true);
63 }
64 out:
65 ftrace_test_recursion_unlock(bit);
66 }
Link: https://lore.kernel.org/all/168100731160.79534.374827110083836722.stgit@devnote2/
Reported-by: Dan Carpenter <[email protected]>
Link: https://lore.kernel.org/all/[email protected]
Fixes: 39d954200bf6 ("fprobe: Skip exit_handler if entry_handler returns !0")
Acked-by: Dan Carpenter <[email protected]>
Signed-off-by: Masami Hiramatsu (Google) <[email protected]>
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Some netdevices may get unregistered before late_initcall(),
we have to move the hashtable init earlier.
Fixes: f1fc43d03946 ("bpf: Move offload initialization into late_initcall")
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=217399
Signed-off-by: Jakub Kicinski <[email protected]>
Acked-by: Stanislav Fomichev <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Alexei Starovoitov <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking fix from Borislav Petkov:
- Make sure __down_read_common() is always inlined so that the callers'
names land in traceevents output and thus the blocked function can be
identified
* tag 'locking_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/rwsem: Add __always_inline annotation to __down_read_common() and inlined callers
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf fixes from Borislav Petkov:
- Make sure the PEBS buffer is flushed before reprogramming the
hardware so that the correct record sizes are used
- Update the sample size for AMD BRS events
- Fix a confusion with using the same on-stack struct with different
events in the event processing path
* tag 'perf_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/ds: Flush PEBS DS when changing PEBS_DATA_CFG
perf/x86: Fix missing sample size update on AMD BRS
perf/core: Fix perf_sample_data not properly initialized for different swevents in perf_tp_event()
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fix from Borislav Petkov:
- Fix a couple of kernel-doc warnings
* tag 'sched_urgent_for_v6.4_rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched: fix cid_lock kernel-doc warnings
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When a tick broadcast clockevent device is initialized for one shot mode
then tick_broadcast_setup_oneshot() OR's the periodic broadcast mode
cpumask into the oneshot broadcast cpumask.
This is required when switching from periodic broadcast mode to oneshot
broadcast mode to ensure that CPUs which are waiting for periodic
broadcast are woken up on the next tick.
But it is subtly broken, when an active broadcast device is replaced and
the system is already in oneshot (NOHZ/HIGHRES) mode. Victor observed
this and debugged the issue.
Then the OR of the periodic broadcast CPU mask is wrong as the periodic
cpumask bits are sticky after tick_broadcast_enable() set it for a CPU
unless explicitly cleared via tick_broadcast_disable().
That means that this sets all other CPUs which have tick broadcasting
enabled at that point unconditionally in the oneshot broadcast mask.
If the affected CPUs were already idle and had their bits set in the
oneshot broadcast mask then this does no harm. But for non idle CPUs
which were not set this corrupts their state.
On their next invocation of tick_broadcast_enable() they observe the bit
set, which indicates that the broadcast for the CPU is already set up.
As a consequence they fail to update the broadcast event even if their
earliest expiring timer is before the actually programmed broadcast
event.
If the programmed broadcast event is far in the future, then this can
cause stalls or trigger the hung task detector.
Avoid this by telling tick_broadcast_setup_oneshot() explicitly whether
this is the initial switch over from periodic to oneshot broadcast which
must take the periodic broadcast mask into account. In the case of
initialization of a replacement device this prevents that the broadcast
oneshot mask is modified.
There is a second problem with broadcast device replacement in this
function. The broadcast device is only armed when the previous state of
the device was periodic.
That is correct for the switch from periodic broadcast mode to oneshot
broadcast mode as the underlying broadcast device could operate in
oneshot state already due to lack of periodic state in hardware. In that
case it is already armed to expire at the next tick.
For the replacement case this is wrong as the device is in shutdown
state. That means that any already pending broadcast event will not be
armed.
This went unnoticed because any CPU which goes idle will observe that
the broadcast device has an expiry time of KTIME_MAX and therefore any
CPUs next timer event will be earlier and cause a reprogramming of the
broadcast device. But that does not guarantee that the events of the
CPUs which were already in idle are delivered on time.
Fix this by arming the newly installed device for an immediate event
which will reevaluate the per CPU expiry times and reprogram the
broadcast device accordingly. This is simpler than caching the last
expiry time in yet another place or saving it before the device exchange
and handing it down to the setup function. Replacement of broadcast
devices is not a frequent operation and usually happens once somewhere
late in the boot process.
Fixes: 9c336c9935cf ("tick/broadcast: Allow late registered device to enter oneshot mode")
Reported-by: Victor Hassan <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Reviewed-by: Frederic Weisbecker <[email protected]>
Link: https://lore.kernel.org/r/87pm7d2z1i.ffs@tglx
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Fix kernel-doc warnings for cid_lock and use_cid_lock.
These comments are not in kernel-doc format.
kernel/sched/core.c:11496: warning: Cannot understand * @cid_lock: Guarantee forward-progress of cid allocation.
on line 11496 - I thought it was a doc line
kernel/sched/core.c:11505: warning: Cannot understand * @use_cid_lock: Select cid allocation behavior: lock-free vs spinlock.
on line 11505 - I thought it was a doc line
Fixes: 223baf9d17f2 ("sched: Fix performance regression introduced by mm_cid")
Signed-off-by: Randy Dunlap <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
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swevents in perf_tp_event()
data->sample_flags may be modified in perf_prepare_sample(),
in perf_tp_event(), different swevents use the same on-stack
perf_sample_data, the previous swevent may change sample_flags in
perf_prepare_sample(), as a result, some members of perf_sample_data are
not correctly initialized when next swevent_event preparing sample
(for example data->id, the value varies according to swevent).
A simple scenario triggers this problem is as follows:
# perf record -e sched:sched_switch --switch-output-event sched:sched_switch -a sleep 1
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209014396 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209014662 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209014910 ]
[ perf record: Woken up 0 times to write data ]
[ perf record: Dump perf.data.2023041209015164 ]
[ perf record: Captured and wrote 0.069 MB perf.data.<timestamp> ]
# ls -l
total 860
-rw------- 1 root root 95694 Apr 12 09:01 perf.data.2023041209014396
-rw------- 1 root root 606430 Apr 12 09:01 perf.data.2023041209014662
-rw------- 1 root root 82246 Apr 12 09:01 perf.data.2023041209014910
-rw------- 1 root root 82342 Apr 12 09:01 perf.data.2023041209015164
# perf script -i perf.data.2023041209014396
0x11d58 [0x80]: failed to process type: 9 [Bad address]
Solution: Re-initialize perf_sample_data after each event is processed.
Note that data->raw->frag.data may be accessed in perf_tp_event_match().
Therefore, need to init sample_data and then go through swevent hlist to prevent
reference of NULL pointer, reported by [1].
After fix:
# perf record -e sched:sched_switch --switch-output-event sched:sched_switch -a sleep 1
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209442259 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209442514 ]
[ perf record: dump data: Woken up 0 times ]
[ perf record: Dump perf.data.2023041209442760 ]
[ perf record: Woken up 0 times to write data ]
[ perf record: Dump perf.data.2023041209443003 ]
[ perf record: Captured and wrote 0.069 MB perf.data.<timestamp> ]
# ls -l
total 864
-rw------- 1 root root 100166 Apr 12 09:44 perf.data.2023041209442259
-rw------- 1 root root 606438 Apr 12 09:44 perf.data.2023041209442514
-rw------- 1 root root 82246 Apr 12 09:44 perf.data.2023041209442760
-rw------- 1 root root 82342 Apr 12 09:44 perf.data.2023041209443003
# perf script -i perf.data.2023041209442259 | head -n 5
perf 232 [000] 66.846217: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=D ==> next_comm=perf next_pid=234 next_prio=120
perf 234 [000] 66.846449: sched:sched_switch: prev_comm=perf prev_pid=234 prev_prio=120 prev_state=S ==> next_comm=perf next_pid=232 next_prio=120
perf 232 [000] 66.846546: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=R ==> next_comm=perf next_pid=234 next_prio=120
perf 234 [000] 66.846606: sched:sched_switch: prev_comm=perf prev_pid=234 prev_prio=120 prev_state=S ==> next_comm=perf next_pid=232 next_prio=120
perf 232 [000] 66.846646: sched:sched_switch: prev_comm=perf prev_pid=232 prev_prio=120 prev_state=R ==> next_comm=perf next_pid=234 next_prio=120
[1] Link: https://lore.kernel.org/oe-lkp/[email protected]
Fixes: bb447c27a467 ("perf/core: Set data->sample_flags in perf_prepare_sample()")
Signed-off-by: Yang Jihong <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Link: https://lkml.kernel.org/r/[email protected]
|
|
inlined callers
Apparently despite it being marked inline, the compiler
may not inline __down_read_common() which makes it difficult
to identify the cause of lock contention, as the blocked
function in traceevents will always be listed as
__down_read_common().
So this patch adds __always_inline annotation to the common
function (as well as the inlined helper callers) to force it to
be inlined so the blocking function will be listed (via Wchan)
in traceevents.
Fixes: c995e638ccbb ("locking/rwsem: Fold __down_{read,write}*()")
Reported-by: Tim Murray <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Peter Zijlstra (Intel) <[email protected]>
Reviewed-by: Waiman Long <[email protected]>
Cc: [email protected]
Link: https://lkml.kernel.org/r/[email protected]
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull more tracing updates from Steven Rostedt:
- Make buffer_percent read/write.
The buffer_percent file is how users can state how long to block on
the tracing buffer depending on how much is in the buffer. When it
hits the "buffer_percent" it will wake the task waiting on the
buffer. For some reason it was set to read-only.
This was not noticed because testing was done as root without
SELinux, but with SELinux it will prevent even root to write to it
without having CAP_DAC_OVERRIDE.
- The "touched_functions" was added this merge window, but one of the
reasons for adding it was not implemented.
That was to show what functions were not only touched, but had either
a direct trampoline attached to it, or a kprobe or live kernel
patching that can "hijack" the function to run a different function.
The point is to know if there's functions in the kernel that may not
be behaving as the kernel code shows. This can be used for debugging.
TODO: Add this information to kernel oops too.
* tag 'trace-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
ftrace: Add MODIFIED flag to show if IPMODIFY or direct was attached
tracing: Fix permissions for the buffer_percent file
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- Introduce local{,64}_try_cmpxchg() - a slightly more optimal
primitive, which will be used in perf events ring-buffer code
- Simplify/modify rwsems on PREEMPT_RT, to address writer starvation
- Misc cleanups/fixes
* tag 'locking-core-2023-05-05' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
locking/atomic: Correct (cmp)xchg() instrumentation
locking/x86: Define arch_try_cmpxchg_local()
locking/arch: Wire up local_try_cmpxchg()
locking/generic: Wire up local{,64}_try_cmpxchg()
locking/atomic: Add generic try_cmpxchg{,64}_local() support
locking/rwbase: Mitigate indefinite writer starvation
locking/arch: Rename all internal __xchg() names to __arch_xchg()
|
|
If a function had ever had IPMODIFY or DIRECT attached to it, where this
is how live kernel patching and BPF overrides work, mark them and display
an "M" in the enabled_functions and touched_functions files. This can be
used for debugging. If a function had been modified and later there's a bug
in the code related to that function, this can be used to know if the cause
is possibly from a live kernel patch or a BPF program that changed the
behavior of the code.
Also update the documentation on the enabled_functions and
touched_functions output, as it was missing direct callers and CALL_OPS.
And include this new modify attribute.
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Cc: Mark Rutland <[email protected]>
Acked-by: Masami Hiramatsu (Google) <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull hitfixes from Andrew Morton:
"Five hotfixes. Three are cc:stable, two for this -rc cycle"
* tag 'mm-hotfixes-stable-2023-05-03-16-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm: change per-VMA lock statistics to be disabled by default
MAINTAINERS: update Michal Simek's email
mm/mempolicy: correctly update prev when policy is equal on mbind
relayfs: fix out-of-bounds access in relay_file_read
kasan: hw_tags: avoid invalid virt_to_page()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- Some DAMON cleanups from Kefeng Wang
- Some KSM work from David Hildenbrand, to make the PR_SET_MEMORY_MERGE
ioctl's behavior more similar to KSM's behavior.
[ Andrew called these "final", but I suspect we'll have a series fixing
up the fact that the last commit in the dmapools series in the
previous pull seems to have unintentionally just reverted all the
other commits in the same series.. - Linus ]
* tag 'mm-stable-2023-05-03-16-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm: hwpoison: coredump: support recovery from dump_user_range()
mm/page_alloc: add some comments to explain the possible hole in __pageblock_pfn_to_page()
mm/ksm: move disabling KSM from s390/gmap code to KSM code
selftests/ksm: ksm_functional_tests: add prctl unmerge test
mm/ksm: unmerge and clear VM_MERGEABLE when setting PR_SET_MEMORY_MERGE=0
mm/damon/paddr: fix missing folio_sz update in damon_pa_young()
mm/damon/paddr: minor refactor of damon_pa_mark_accessed_or_deactivate()
mm/damon/paddr: minor refactor of damon_pa_pageout()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull modules fix from Luis Chamberlain:
"One fix by Arnd far for modules which came in after the first pull
request.
The issue was found as part of some late compile tests with 0-day. I
take it 0-day does some secondary late builds with after some initial
ones"
* tag 'modules-6.4-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
module: include internal.h in module/dups.c
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull more sysctl updates from Luis Chamberlain:
"As mentioned on my first pull request for sysctl-next, for v6.4-rc1
we're very close to being able to deprecating register_sysctl_paths().
I was going to assess the situation after the first week of the merge
window.
That time is now and things are looking good. We only have one which
had already an ACK for so I'm picking this up here now and the last
patch is the one that uses an axe.
I have boot tested the last patch and 0-day build completed
successfully"
* tag 'sysctl-6.4-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux:
sysctl: remove register_sysctl_paths()
kernel: pid_namespace: simplify sysctls with register_sysctl()
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull more power management updates from Rafael Wysocki:
"These fix a hibernation test mode regression and clean up the
intel_idle driver.
Specifics:
- Make test_resume work again after the changes that made hibernation
open the snapshot device in exclusive mode (Chen Yu)
- Clean up code in several places in intel_idle (Artem Bityutskiy)"
* tag 'pm-6.4-rc1-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
intel_idle: mark few variables as __read_mostly
intel_idle: do not sprinkle module parameter definitions around
intel_idle: fix confusing message
intel_idle: improve C-state flags handling robustness
intel_idle: further intel_idle_init_cstates_icpu() cleanup
intel_idle: clean up intel_idle_init_cstates_icpu()
intel_idle: use pr_info() instead of printk()
PM: hibernate: Do not get block device exclusively in test_resume mode
PM: hibernate: Turn snapshot_test into global variable
|
|
This file defines both read and write operations, yet it is being
created as read-only. This means that it can't be written to without the
CAP_DAC_OVERRIDE capability. Fix the permissions to allow root to write
to it without the need to override DAC perms.
Link: https://lore.kernel.org/linux-trace-kernel/[email protected]
Cc: [email protected]
Cc: Masami Hiramatsu <[email protected]>
Fixes: 03329f993978 ("tracing: Add tracefs file buffer_percentage")
Signed-off-by: Ondrej Mosnacek <[email protected]>
Signed-off-by: Steven Rostedt (Google) <[email protected]>
|
|
Two newly introduced functions are declared in a header that is not
included before the definition, causing a warning with sparse or
'make W=1':
kernel/module/dups.c:118:6: error: no previous prototype for 'kmod_dup_request_exists_wait' [-Werror=missing-prototypes]
118 | bool kmod_dup_request_exists_wait(char *module_name, bool wait, int *dup_ret)
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
kernel/module/dups.c:220:6: error: no previous prototype for 'kmod_dup_request_announce' [-Werror=missing-prototypes]
220 | void kmod_dup_request_announce(char *module_name, int ret)
| ^~~~~~~~~~~~~~~~~~~~~~~~~
Add an explicit include to ensure the prototypes match.
Fixes: 8660484ed1cf ("module: add debugging auto-load duplicate module support")
Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Luis Chamberlain <[email protected]>
|
|
register_sysctl_paths() is only required if your child (directories)
have entries and pid_namespace does not. So use register_sysctl_init()
instead where we don't care about the return value and use
register_sysctl() where we do.
Signed-off-by: Luis Chamberlain <[email protected]>
Acked-by: Jeff Xu <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
|
|
There is a crash in relay_file_read, as the var from
point to the end of last subbuf.
The oops looks something like:
pc : __arch_copy_to_user+0x180/0x310
lr : relay_file_read+0x20c/0x2c8
Call trace:
__arch_copy_to_user+0x180/0x310
full_proxy_read+0x68/0x98
vfs_read+0xb0/0x1d0
ksys_read+0x6c/0xf0
__arm64_sys_read+0x20/0x28
el0_svc_common.constprop.3+0x84/0x108
do_el0_svc+0x74/0x90
el0_svc+0x1c/0x28
el0_sync_handler+0x88/0xb0
el0_sync+0x148/0x180
We get the condition by analyzing the vmcore:
1). The last produced byte and last consumed byte
both at the end of the last subbuf
2). A softirq calls function(e.g __blk_add_trace)
to write relay buffer occurs when an program is calling
relay_file_read_avail().
relay_file_read
relay_file_read_avail
relay_file_read_consume(buf, 0, 0);
//interrupted by softirq who will write subbuf
....
return 1;
//read_start point to the end of the last subbuf
read_start = relay_file_read_start_pos
//avail is equal to subsize
avail = relay_file_read_subbuf_avail
//from points to an invalid memory address
from = buf->start + read_start
//system is crashed
copy_to_user(buffer, from, avail)
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 8d62fdebdaf9 ("relay file read: start-pos fix")
Signed-off-by: Zhang Zhengming <[email protected]>
Reviewed-by: Zhao Lei <[email protected]>
Reviewed-by: Zhou Kete <[email protected]>
Reviewed-by: Pengcheng Yang <[email protected]>
Cc: Jens Axboe <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
Patch series "mm/ksm: improve PR_SET_MEMORY_MERGE=0 handling and cleanup
disabling KSM", v2.
(1) Make PR_SET_MEMORY_MERGE=0 unmerge pages like setting MADV_UNMERGEABLE
does, (2) add a selftest for it and (3) factor out disabling of KSM from
s390/gmap code.
This patch (of 3):
Let's unmerge any KSM pages when setting PR_SET_MEMORY_MERGE=0, and clear
the VM_MERGEABLE flag from all VMAs -- just like KSM would. Of course,
only do that if we previously set PR_SET_MEMORY_MERGE=1.
Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: David Hildenbrand <[email protected]>
Acked-by: Stefan Roesch <[email protected]>
Cc: Christian Borntraeger <[email protected]>
Cc: Claudio Imbrenda <[email protected]>
Cc: Heiko Carstens <[email protected]>
Cc: Janosch Frank <[email protected]>
Cc: Johannes Weiner <[email protected]>
Cc: Michal Hocko <[email protected]>
Cc: Rik van Riel <[email protected]>
Cc: Shuah Khan <[email protected]>
Cc: Sven Schnelle <[email protected]>
Cc: Vasily Gorbik <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu
Pull iommu updates from Joerg Roedel:
- Convert to platform remove callback returning void
- Extend changing default domain to normal group
- Intel VT-d updates:
- Remove VT-d virtual command interface and IOASID
- Allow the VT-d driver to support non-PRI IOPF
- Remove PASID supervisor request support
- Various small and misc cleanups
- ARM SMMU updates:
- Device-tree binding updates:
* Allow Qualcomm GPU SMMUs to accept relevant clock properties
* Document Qualcomm 8550 SoC as implementing an MMU-500
* Favour new "qcom,smmu-500" binding for Adreno SMMUs
- Fix S2CR quirk detection on non-architectural Qualcomm SMMU
implementations
- Acknowledge SMMUv3 PRI queue overflow when consuming events
- Document (in a comment) why ATS is disabled for bypass streams
- AMD IOMMU updates:
- 5-level page-table support
- NUMA awareness for memory allocations
- Unisoc driver: Support for reattaching an existing domain
- Rockchip driver: Add missing set_platform_dma_ops callback
- Mediatek driver: Adjust the dma-ranges
- Various other small fixes and cleanups
* tag 'iommu-updates-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu: (82 commits)
iommu: Remove iommu_group_get_by_id()
iommu: Make iommu_release_device() static
iommu/vt-d: Remove BUG_ON in dmar_insert_dev_scope()
iommu/vt-d: Remove a useless BUG_ON(dev->is_virtfn)
iommu/vt-d: Remove BUG_ON in map/unmap()
iommu/vt-d: Remove BUG_ON when domain->pgd is NULL
iommu/vt-d: Remove BUG_ON in handling iotlb cache invalidation
iommu/vt-d: Remove BUG_ON on checking valid pfn range
iommu/vt-d: Make size of operands same in bitwise operations
iommu/vt-d: Remove PASID supervisor request support
iommu/vt-d: Use non-privileged mode for all PASIDs
iommu/vt-d: Remove extern from function prototypes
iommu/vt-d: Do not use GFP_ATOMIC when not needed
iommu/vt-d: Remove unnecessary checks in iopf disabling path
iommu/vt-d: Move PRI handling to IOPF feature path
iommu/vt-d: Move pfsid and ats_qdep calculation to device probe path
iommu/vt-d: Move iopf code from SVA to IOPF enabling path
iommu/vt-d: Allow SVA with device-specific IOPF
dmaengine: idxd: Add enable/disable device IOPF feature
arm64: dts: mt8186: Add dma-ranges for the parent "soc" node
...
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Vasily Gorbik:
- Add support for stackleak feature. Also allow specifying
architecture-specific stackleak poison function to enable faster
implementation. On s390, the mvc-based implementation helps decrease
typical overhead from a factor of 3 to just 25%
- Convert all assembler files to use SYM* style macros, deprecating the
ENTRY() macro and other annotations. Select ARCH_USE_SYM_ANNOTATIONS
- Improve KASLR to also randomize module and special amode31 code base
load addresses
- Rework decompressor memory tracking to support memory holes and
improve error handling
- Add support for protected virtualization AP binding
- Add support for set_direct_map() calls
- Implement set_memory_rox() and noexec module_alloc()
- Remove obsolete overriding of mem*() functions for KASAN
- Rework kexec/kdump to avoid using nodat_stack to call purgatory
- Convert the rest of the s390 code to use flexible-array member
instead of a zero-length array
- Clean up uaccess inline asm
- Enable ARCH_HAS_MEMBARRIER_SYNC_CORE
- Convert to using CONFIG_FUNCTION_ALIGNMENT and enable
DEBUG_FORCE_FUNCTION_ALIGN_64B
- Resolve last_break in userspace fault reports
- Simplify one-level sysctl registration
- Clean up branch prediction handling
- Rework CPU counter facility to retrieve available counter sets just
once
- Other various small fixes and improvements all over the code
* tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (118 commits)
s390/stackleak: provide fast __stackleak_poison() implementation
stackleak: allow to specify arch specific stackleak poison function
s390: select ARCH_USE_SYM_ANNOTATIONS
s390/mm: use VM_FLUSH_RESET_PERMS in module_alloc()
s390: wire up memfd_secret system call
s390/mm: enable ARCH_HAS_SET_DIRECT_MAP
s390/mm: use BIT macro to generate SET_MEMORY bit masks
s390/relocate_kernel: adjust indentation
s390/relocate_kernel: use SYM* macros instead of ENTRY(), etc.
s390/entry: use SYM* macros instead of ENTRY(), etc.
s390/purgatory: use SYM* macros instead of ENTRY(), etc.
s390/kprobes: use SYM* macros instead of ENTRY(), etc.
s390/reipl: use SYM* macros instead of ENTRY(), etc.
s390/head64: use SYM* macros instead of ENTRY(), etc.
s390/earlypgm: use SYM* macros instead of ENTRY(), etc.
s390/mcount: use SYM* macros instead of ENTRY(), etc.
s390/crc32le: use SYM* macros instead of ENTRY(), etc.
s390/crc32be: use SYM* macros instead of ENTRY(), etc.
s390/crypto,chacha: use SYM* macros instead of ENTRY(), etc.
s390/amode31: use SYM* macros instead of ENTRY(), etc.
...
|
|
git://git.infradead.org/users/hch/dma-mapping
Pull dma-mapping updates from Christoph Hellwig:
- fix a PageHighMem check in dma-coherent initialization (Doug Berger)
- clean up the coherency defaul initialiation (Jiaxun Yang)
- add cacheline to user/kernel dma-debug space dump messages (Desnes
Nunes, Geert Uytterhoeve)
- swiotlb statistics improvements (Michael Kelley)
- misc cleanups (Petr Tesarik)
* tag 'dma-mapping-6.4-2023-04-28' of git://git.infradead.org/users/hch/dma-mapping:
swiotlb: Omit total_used and used_hiwater if !CONFIG_DEBUG_FS
swiotlb: track and report io_tlb_used high water marks in debugfs
swiotlb: fix debugfs reporting of reserved memory pools
swiotlb: relocate PageHighMem test away from rmem_swiotlb_setup
of: address: always use dma_default_coherent for default coherency
dma-mapping: provide CONFIG_ARCH_DMA_DEFAULT_COHERENT
dma-mapping: provide a fallback dma_default_coherent
dma-debug: Use %pa to format phys_addr_t
dma-debug: add cacheline to user/kernel space dump messages
dma-debug: small dma_debug_entry's comment and variable name updates
dma-direct: cleanup parameters to dma_direct_optimal_gfp_mask
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull more timer updates from Thomas Gleixner:
"Timekeeping and clocksource/event driver updates the second batch:
- A trivial documentation fix in the timekeeping core
- A really boring set of small fixes, enhancements and cleanups in
the drivers code. No new clocksource/clockevent drivers for a
change"
* tag 'timers-core-2023-04-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
timekeeping: Fix references to nonexistent ktime_get_fast_ns()
dt-bindings: timer: rockchip: Add rk3588 compatible
dt-bindings: timer: rockchip: Drop superfluous rk3288 compatible
clocksource/drivers/ti: Use of_property_read_bool() for boolean properties
clocksource/drivers/timer-ti-dm: Fix finding alwon timer
clocksource/drivers/davinci: Fix memory leak in davinci_timer_register when init fails
clocksource/drivers/stm32-lp: Drop of_match_ptr for ID table
clocksource/drivers/timer-ti-dm: Convert to platform remove callback returning void
clocksource/drivers/timer-tegra186: Convert to platform remove callback returning void
clocksource/drivers/timer-ti-dm: Improve error message in .remove
clocksource/drivers/timer-stm32-lp: Mark driver as non-removable
clocksource/drivers/sh_mtu2: Mark driver as non-removable
clocksource/drivers/timer-ti-dm: Use of_address_to_resource()
clocksource/drivers/timer-imx-gpt: Remove non-DT function
clocksource/drivers/timer-mediatek: Split out CPUXGPT timers
clocksource/drivers/exynos_mct: Explicitly return 0 for shared timer
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup
Pull cgroup updates from Tejun Heo:
- cpuset changes including the fix for an incorrect interaction with
CPU hotplug and an optimization
- Other doc and cosmetic changes
* tag 'cgroup-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup:
docs: cgroup-v1/cpusets: update libcgroup project link
cgroup/cpuset: Minor updates to test_cpuset_prs.sh
cgroup/cpuset: Include offline CPUs when tasks' cpumasks in top_cpuset are updated
cgroup/cpuset: Skip task update if hotplug doesn't affect current cpuset
cpuset: Clean up cpuset_node_allowed
cgroup: bpf: use cgroup_lock()/cgroup_unlock() wrappers
|
|
Pull workqueue updates from Tejun Heo:
"Mostly changes from Petr to improve warning and error reporting.
Workqueue now reports more of the relevant failures with better
context which should help debugging"
* tag 'wq-for-6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Introduce show_freezable_workqueues
workqueue: Print backtraces from CPUs with hung CPU bound workqueues
workqueue: Warn when a rescuer could not be created
workqueue: Interrupted create_worker() is not a repeated event
workqueue: Warn when a new worker could not be created
workqueue: Fix hung time report of worker pools
workqueue: Simplify a pr_warn() call in wq_select_unbound_cpu()
MAINTAINERS: Add workqueue_internal.h to the WORKQUEUE entry
|
|
On PREEMPT_RT, rw_semaphore and rwlock_t locks are unfair to writers.
Readers can indefinitely acquire the lock unless the writer fully acquired
the lock, which might never happen if there is always a reader in the
critical section owning the lock.
Mel Gorman reported that since LTP-20220121 the dio_truncate test case
went from having 1 reader to having 16 readers and that number of readers
is sufficient to prevent the down_write ever succeeding while readers
exist. Eventually the test is killed after 30 minutes as a failure.
Mel proposed a timeout to limit how long a writer can be blocked until
the reader is forced into the slowpath.
Thomas argued that there is no added value by providing this timeout. From
a PREEMPT_RT point of view, there are no critical rw_semaphore or rwlock_t
locks left where the reader must be preferred.
Mitigate indefinite writer starvation by forcing the READER into the
slowpath once the WRITER attempts to acquire the lock.
Reported-by: Mel Gorman <[email protected]>
Signed-off-by: Sebastian Andrzej Siewior <[email protected]>
Signed-off-by: Thomas Gleixner <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Acked-by: Mel Gorman <[email protected]>
Link: https://lore.kernel.org/877cwbq4cq.ffs@tglx
Link: https://lore.kernel.org/r/[email protected]
Cc: Linus Torvalds <[email protected]>
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing tools updates from Steven Rostedt:
- Add auto-analysis only option to rtla/timerlat
Add an --aa-only option to the tooling to perform only the auto
analysis and not to parse and format the data.
- Other minor fixes and clean ups
* tag 'trace-tools-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
rtla/timerlat: Fix "Previous IRQ" auto analysis' line
rtla/timerlat: Add auto-analysis only option
rv: Remove redundant assignment to variable retval
rv: Fix addition on an uninitialized variable 'run'
rtla: Add .gitignore file
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git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace
Pull tracing updates from Steven Rostedt:
- User events are finally ready!
After lots of collaboration between various parties, we finally
locked down on a stable interface for user events that can also work
with user space only tracing.
This is implemented by telling the kernel (or user space library, but
that part is user space only and not part of this patch set), where
the variable is that the application uses to know if something is
listening to the trace.
There's also an interface to tell the kernel about these events,
which will show up in the /sys/kernel/tracing/events/user_events/
directory, where it can be enabled.
When it's enabled, the kernel will update the variable, to tell the
application to start writing to the kernel.
See https://lwn.net/Articles/927595/
- Cleaned up the direct trampolines code to simplify arm64 addition of
direct trampolines.
Direct trampolines use the ftrace interface but instead of jumping to
the ftrace trampoline, applications (mostly BPF) can register their
own trampoline for performance reasons.
- Some updates to the fprobe infrastructure. fprobes are more efficient
than kprobes, as it does not need to save all the registers that
kprobes on ftrace do. More work needs to be done before the fprobes
will be exposed as dynamic events.
- More updates to references to the obsolete path of
/sys/kernel/debug/tracing for the new /sys/kernel/tracing path.
- Add a seq_buf_do_printk() helper to seq_bufs, to print a large buffer
line by line instead of all at once.
There are users in production kernels that have a large data dump
that originally used printk() directly, but the data dump was larger
than what printk() allowed as a single print.
Using seq_buf() to do the printing fixes that.
- Add /sys/kernel/tracing/touched_functions that shows all functions
that was every traced by ftrace or a direct trampoline. This is used
for debugging issues where a traced function could have caused a
crash by a bpf program or live patching.
- Add a "fields" option that is similar to "raw" but outputs the fields
of the events. It's easier to read by humans.
- Some minor fixes and clean ups.
* tag 'trace-v6.4' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: (41 commits)
ring-buffer: Sync IRQ works before buffer destruction
tracing: Add missing spaces in trace_print_hex_seq()
ring-buffer: Ensure proper resetting of atomic variables in ring_buffer_reset_online_cpus
recordmcount: Fix memory leaks in the uwrite function
tracing/user_events: Limit max fault-in attempts
tracing/user_events: Prevent same address and bit per process
tracing/user_events: Ensure bit is cleared on unregister
tracing/user_events: Ensure write index cannot be negative
seq_buf: Add seq_buf_do_printk() helper
tracing: Fix print_fields() for __dyn_loc/__rel_loc
tracing/user_events: Set event filter_type from type
ring-buffer: Clearly check null ptr returned by rb_set_head_page()
tracing: Unbreak user events
tracing/user_events: Use print_format_fields() for trace output
tracing/user_events: Align structs with tabs for readability
tracing/user_events: Limit global user_event count
tracing/user_events: Charge event allocs to cgroups
tracing/user_events: Update documentation for ABI
tracing/user_events: Use write ABI in example
tracing/user_events: Add ABI self-test
...
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull SMP cross-CPU function-call updates from Ingo Molnar:
- Remove diagnostics and adjust config for CSD lock diagnostics
- Add a generic IPI-sending tracepoint, as currently there's no easy
way to instrument IPI origins: it's arch dependent and for some major
architectures it's not even consistently available.
* tag 'smp-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
trace,smp: Trace all smp_function_call*() invocations
trace: Add trace_ipi_send_cpu()
sched, smp: Trace smp callback causing an IPI
smp: reword smp call IPI comment
treewide: Trace IPIs sent via smp_send_reschedule()
irq_work: Trace self-IPIs sent via arch_irq_work_raise()
smp: Trace IPIs sent via arch_send_call_function_ipi_mask()
sched, smp: Trace IPIs sent via send_call_function_single_ipi()
trace: Add trace_ipi_send_cpumask()
kernel/smp: Make csdlock_debug= resettable
locking/csd_lock: Remove per-CPU data indirection from CSD lock debugging
locking/csd_lock: Remove added data from CSD lock debugging
locking/csd_lock: Add Kconfig option for csd_debug default
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler updates from Ingo Molnar:
- Allow unprivileged PSI poll()ing
- Fix performance regression introduced by mm_cid
- Improve livepatch stalls by adding livepatch task switching to
cond_resched(). This resolves livepatching busy-loop stalls with
certain CPU-bound kthreads
- Improve sched_move_task() performance on autogroup configs
- On core-scheduling CPUs, avoid selecting throttled tasks to run
- Misc cleanups, fixes and improvements
* tag 'sched-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
sched/clock: Fix local_clock() before sched_clock_init()
sched/rt: Fix bad task migration for rt tasks
sched: Fix performance regression introduced by mm_cid
sched/core: Make sched_dynamic_mutex static
sched/psi: Allow unprivileged polling of N*2s period
sched/psi: Extract update_triggers side effect
sched/psi: Rename existing poll members in preparation
sched/psi: Rearrange polling code in preparation
sched/fair: Fix inaccurate tally of ttwu_move_affine
vhost: Fix livepatch timeouts in vhost_worker()
livepatch,sched: Add livepatch task switching to cond_resched()
livepatch: Skip task_call_func() for current task
livepatch: Convert stack entries array to percpu
sched: Interleave cfs bandwidth timers for improved single thread performance at low utilization
sched/core: Reduce cost of sched_move_task when config autogroup
sched/core: Avoid selecting the task that is throttled to run when core-sched enable
sched/topology: Make sched_energy_mutex,update static
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull perf updates from Ingo Molnar:
- Add Intel Granite Rapids support
- Add uncore events for Intel SPR IMC PMU
- Fix perf IRQ throttling bug
* tag 'perf-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
perf/x86/intel/uncore: Add events for Intel SPR IMC PMU
perf/core: Fix hardlockup failure caused by perf throttle
perf/x86/cstate: Add Granite Rapids support
perf/x86/msr: Add Granite Rapids
perf/x86/intel: Add Granite Rapids
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool updates from Ingo Molnar:
- Mark arch_cpu_idle_dead() __noreturn, make all architectures &
drivers that did this inconsistently follow this new, common
convention, and fix all the fallout that objtool can now detect
statically
- Fix/improve the ORC unwinder becoming unreliable due to
UNWIND_HINT_EMPTY ambiguity, split it into UNWIND_HINT_END_OF_STACK
and UNWIND_HINT_UNDEFINED to resolve it
- Fix noinstr violations in the KCSAN code and the lkdtm/stackleak code
- Generate ORC data for __pfx code
- Add more __noreturn annotations to various kernel startup/shutdown
and panic functions
- Misc improvements & fixes
* tag 'objtool-core-2023-04-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
x86/hyperv: Mark hv_ghcb_terminate() as noreturn
scsi: message: fusion: Mark mpt_halt_firmware() __noreturn
x86/cpu: Mark {hlt,resume}_play_dead() __noreturn
btrfs: Mark btrfs_assertfail() __noreturn
objtool: Include weak functions in global_noreturns check
cpu: Mark nmi_panic_self_stop() __noreturn
cpu: Mark panic_smp_self_stop() __noreturn
arm64/cpu: Mark cpu_park_loop() and friends __noreturn
x86/head: Mark *_start_kernel() __noreturn
init: Mark start_kernel() __noreturn
init: Mark [arch_call_]rest_init() __noreturn
objtool: Generate ORC data for __pfx code
x86/linkage: Fix padding for typed functions
objtool: Separate prefix code from stack validation code
objtool: Remove superfluous dead_end_function() check
objtool: Add symbol iteration helpers
objtool: Add WARN_INSN()
scripts/objdump-func: Support multiple functions
context_tracking: Fix KCSAN noinstr violation
objtool: Add stackleak instrumentation to uaccess safe list
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull non-MM updates from Andrew Morton:
"Mainly singleton patches all over the place.
Series of note are:
- updates to scripts/gdb from Glenn Washburn
- kexec cleanups from Bjorn Helgaas"
* tag 'mm-nonmm-stable-2023-04-27-16-01' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (50 commits)
mailmap: add entries for Paul Mackerras
libgcc: add forward declarations for generic library routines
mailmap: add entry for Oleksandr
ocfs2: reduce ioctl stack usage
fs/proc: add Kthread flag to /proc/$pid/status
ia64: fix an addr to taddr in huge_pte_offset()
checkpatch: introduce proper bindings license check
epoll: rename global epmutex
scripts/gdb: add GDB convenience functions $lx_dentry_name() and $lx_i_dentry()
scripts/gdb: create linux/vfs.py for VFS related GDB helpers
uapi/linux/const.h: prefer ISO-friendly __typeof__
delayacct: track delays from IRQ/SOFTIRQ
scripts/gdb: timerlist: convert int chunks to str
scripts/gdb: print interrupts
scripts/gdb: raise error with reduced debugging information
scripts/gdb: add a Radix Tree Parser
lib/rbtree: use '+' instead of '|' for setting color.
proc/stat: remove arch_idle_time()
checkpatch: check for misuse of the link tags
checkpatch: allow Closes tags with links
...
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- Nick Piggin's "shoot lazy tlbs" series, to improve the peformance of
switching from a user process to a kernel thread.
- More folio conversions from Kefeng Wang, Zhang Peng and Pankaj
Raghav.
- zsmalloc performance improvements from Sergey Senozhatsky.
- Yue Zhao has found and fixed some data race issues around the
alteration of memcg userspace tunables.
- VFS rationalizations from Christoph Hellwig:
- removal of most of the callers of write_one_page()
- make __filemap_get_folio()'s return value more useful
- Luis Chamberlain has changed tmpfs so it no longer requires swap
backing. Use `mount -o noswap'.
- Qi Zheng has made the slab shrinkers operate locklessly, providing
some scalability benefits.
- Keith Busch has improved dmapool's performance, making part of its
operations O(1) rather than O(n).
- Peter Xu adds the UFFD_FEATURE_WP_UNPOPULATED feature to userfaultd,
permitting userspace to wr-protect anon memory unpopulated ptes.
- Kirill Shutemov has changed MAX_ORDER's meaning to be inclusive
rather than exclusive, and has fixed a bunch of errors which were
caused by its unintuitive meaning.
- Axel Rasmussen give userfaultfd the UFFDIO_CONTINUE_MODE_WP feature,
which causes minor faults to install a write-protected pte.
- Vlastimil Babka has done some maintenance work on vma_merge():
cleanups to the kernel code and improvements to our userspace test
harness.
- Cleanups to do_fault_around() by Lorenzo Stoakes.
- Mike Rapoport has moved a lot of initialization code out of various
mm/ files and into mm/mm_init.c.
- Lorenzo Stoakes removd vmf_insert_mixed_prot(), which was added for
DRM, but DRM doesn't use it any more.
- Lorenzo has also coverted read_kcore() and vread() to use iterators
and has thereby removed the use of bounce buffers in some cases.
- Lorenzo has also contributed further cleanups of vma_merge().
- Chaitanya Prakash provides some fixes to the mmap selftesting code.
- Matthew Wilcox changes xfs and afs so they no longer take sleeping
locks in ->map_page(), a step towards RCUification of pagefaults.
- Suren Baghdasaryan has improved mmap_lock scalability by switching to
per-VMA locking.
- Frederic Weisbecker has reworked the percpu cache draining so that it
no longer causes latency glitches on cpu isolated workloads.
- Mike Rapoport cleans up and corrects the ARCH_FORCE_MAX_ORDER Kconfig
logic.
- Liu Shixin has changed zswap's initialization so we no longer waste a
chunk of memory if zswap is not being used.
- Yosry Ahmed has improved the performance of memcg statistics
flushing.
- David Stevens has fixed several issues involving khugepaged,
userfaultfd and shmem.
- Christoph Hellwig has provided some cleanup work to zram's IO-related
code paths.
- David Hildenbrand has fixed up some issues in the selftest code's
testing of our pte state changing.
- Pankaj Raghav has made page_endio() unneeded and has removed it.
- Peter Xu contributed some rationalizations of the userfaultfd
selftests.
- Yosry Ahmed has fixed an issue around memcg's page recalim
accounting.
- Chaitanya Prakash has fixed some arm-related issues in the
selftests/mm code.
- Longlong Xia has improved the way in which KSM handles hwpoisoned
pages.
- Peter Xu fixes a few issues with uffd-wp at fork() time.
- Stefan Roesch has changed KSM so that it may now be used on a
per-process and per-cgroup basis.
* tag 'mm-stable-2023-04-27-15-30' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits)
mm,unmap: avoid flushing TLB in batch if PTE is inaccessible
shmem: restrict noswap option to initial user namespace
mm/khugepaged: fix conflicting mods to collapse_file()
sparse: remove unnecessary 0 values from rc
mm: move 'mmap_min_addr' logic from callers into vm_unmapped_area()
hugetlb: pte_alloc_huge() to replace huge pte_alloc_map()
maple_tree: fix allocation in mas_sparse_area()
mm: do not increment pgfault stats when page fault handler retries
zsmalloc: allow only one active pool compaction context
selftests/mm: add new selftests for KSM
mm: add new KSM process and sysfs knobs
mm: add new api to enable ksm per process
mm: shrinkers: fix debugfs file permissions
mm: don't check VMA write permissions if the PTE/PMD indicates write permissions
migrate_pages_batch: fix statistics for longterm pin retry
userfaultfd: use helper function range_in_vma()
lib/show_mem.c: use for_each_populated_zone() simplify code
mm: correct arg in reclaim_pages()/reclaim_clean_pages_from_list()
fs/buffer: convert create_page_buffers to folio_create_buffers
fs/buffer: add folio_create_empty_buffers helper
...
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git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux
Pull hyperv updates from Wei Liu:
- PCI passthrough for Hyper-V confidential VMs (Michael Kelley)
- Hyper-V VTL mode support (Saurabh Sengar)
- Move panic report initialization code earlier (Long Li)
- Various improvements and bug fixes (Dexuan Cui and Michael Kelley)
* tag 'hyperv-next-signed-20230424' of git://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux: (22 commits)
PCI: hv: Replace retarget_msi_interrupt_params with hyperv_pcpu_input_arg
Drivers: hv: move panic report code from vmbus to hv early init code
x86/hyperv: VTL support for Hyper-V
Drivers: hv: Kconfig: Add HYPERV_VTL_MODE
x86/hyperv: Make hv_get_nmi_reason public
x86/hyperv: Add VTL specific structs and hypercalls
x86/init: Make get/set_rtc_noop() public
x86/hyperv: Exclude lazy TLB mode CPUs from enlightened TLB flushes
x86/hyperv: Add callback filter to cpumask_to_vpset()
Drivers: hv: vmbus: Remove the per-CPU post_msg_page
clocksource: hyper-v: make sure Invariant-TSC is used if it is available
PCI: hv: Enable PCI pass-thru devices in Confidential VMs
Drivers: hv: Don't remap addresses that are above shared_gpa_boundary
hv_netvsc: Remove second mapping of send and recv buffers
Drivers: hv: vmbus: Remove second way of mapping ring buffers
Drivers: hv: vmbus: Remove second mapping of VMBus monitor pages
swiotlb: Remove bounce buffer remapping for Hyper-V
Driver: VMBus: Add Devicetree support
dt-bindings: bus: Add Hyper-V VMBus
Drivers: hv: vmbus: Convert acpi_device to more generic platform_device
...
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git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux
Pull hardening update from Kees Cook:
- Fix kheaders array declaration to avoid tripping FORTIFY_SOURCE
* tag 'hardening-v6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
kheaders: Use array declaration instead of char
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git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux
Pull sysctl updates from Luis Chamberlain:
"This only does a few sysctl moves from the kernel/sysctl.c file, the
rest of the work has been put towards deprecating two API calls which
incur recursion and prevent us from simplifying the registration
process / saving memory per move. Most of the changes have been
soaking on linux-next since v6.3-rc3.
I've slowed down the kernel/sysctl.c moves due to Matthew Wilcox's
feedback that we should see if we could *save* memory with these moves
instead of incurring more memory. We currently incur more memory since
when we move a syctl from kernel/sysclt.c out to its own file we end
up having to add a new empty sysctl used to register it. To achieve
saving memory we want to allow syctls to be passed without requiring
the end element being empty, and just have our registration process
rely on ARRAY_SIZE(). Without this, supporting both styles of sysctls
would make the sysctl registration pretty brittle, hard to read and
maintain as can be seen from Meng Tang's efforts to do just this [0].
Fortunately, in order to use ARRAY_SIZE() for all sysctl registrations
also implies doing the work to deprecate two API calls which use
recursion in order to support sysctl declarations with subdirectories.
And so during this development cycle quite a bit of effort went into
this deprecation effort. I've annotated the following two APIs are
deprecated and in few kernel releases we should be good to remove
them:
- register_sysctl_table()
- register_sysctl_paths()
During this merge window we should be able to deprecate and unexport
register_sysctl_paths(), we can probably do that towards the end of
this merge window.
Deprecating register_sysctl_table() will take a bit more time but this
pull request goes with a few example of how to do this.
As it turns out each of the conversions to move away from either of
these two API calls *also* saves memory. And so long term, all these
changes *will* prove to have saved a bit of memory on boot.
The way I see it then is if remove a user of one deprecated call, it
gives us enough savings to move one kernel/sysctl.c out from the
generic arrays as we end up with about the same amount of bytes.
Since deprecating register_sysctl_table() and register_sysctl_paths()
does not require maintainer coordination except the final unexport
you'll see quite a bit of these changes from other pull requests, I've
just kept the stragglers after rc3"
Link: https://lkml.kernel.org/r/[email protected] [0]
* tag 'sysctl-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mcgrof/linux: (29 commits)
fs: fix sysctls.c built
mm: compaction: remove incorrect #ifdef checks
mm: compaction: move compaction sysctl to its own file
mm: memory-failure: Move memory failure sysctls to its own file
arm: simplify two-level sysctl registration for ctl_isa_vars
ia64: simplify one-level sysctl registration for kdump_ctl_table
utsname: simplify one-level sysctl registration for uts_kern_table
ntfs: simplfy one-level sysctl registration for ntfs_sysctls
coda: simplify one-level sysctl registration for coda_table
fs/cachefiles: simplify one-level sysctl registration for cachefiles_sysctls
xfs: simplify two-level sysctl registration for xfs_table
nfs: simplify two-level sysctl registration for nfs_cb_sysctls
nfs: simplify two-level sysctl registration for nfs4_cb_sysctls
lockd: simplify two-level sysctl registration for nlm_sysctls
proc_sysctl: enhance documentation
xen: simplify sysctl registration for balloon
md: simplify sysctl registration
hv: simplify sysctl registration
scsi: simplify sysctl registration with register_sysctl()
csky: simplify alignment sysctl registration
...
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