We currently push everyone to use padding to align 64b values
in netlink. Un-padded nla_put_u64() doesn't even exist any more.
The story behind this possibly start with this thread:
https://lore.kernel.org/netdev/20121204.130914.1457976839967676240.davem@davemloft.net/
where DaveM was concerned about the alignment of a structure
containing 64b stats. If user space tries to access such struct
directly:
struct some_stats *stats = nla_data(attr);
printf("A: %llu", stats->a);
lack of alignment may become problematic for some architectures.
These days we most often put every single member in a separate
attribute, meaning that the code above would use a helper like
nla_get_u64(), which can deal with alignment internally.
Even for arches which don't have good unaligned access - access
aligned to 4B should be pretty efficient.
Kernel and well known libraries deal with unaligned input already.
Padded 64b is quite space-inefficient (64b + pad means at worst 16B
per attr vs 32b which takes 8B). It is also more typing:
if (nla_put_u64_pad(rsp, NETDEV_A_SOMETHING_SOMETHING,
value, NETDEV_A_SOMETHING_PAD))
Create a new attribute type which will use 32 bits at netlink
level if value is small enough (probably most of the time?),
and (4B-aligned) 64 bits otherwise. Kernel API is just:
if (nla_put_uint(rsp, NETDEV_A_SOMETHING_SOMETHING, value))
Calling this new type "just" sint / uint with no specific size
will hopefully also make people more comfortable with using it.
Currently telling people "don't use u8, you may need the bits,
and netlink will round up to 4B, anyway" is the #1 comment
we give to newcomers.
In terms of netlink layout it looks like this:
0 4 8 12 16
32b: [nlattr][ u32 ]
64b: [ pad ][nlattr][ u64 ]
uint(32) [nlattr][ u32 ]
uint(64) [nlattr][ u64 ]
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch adds genradix_peek_prev(), genradix_iter_rewind(), and
genradix_for_each_reverse(), for iterating backwards over a generic
radix tree.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
When we started spreading new inode numbers throughout most of the 64
bit inode space, that triggered some corner case bugs, in particular
some integer overflows related to the radix tree code. Oops.
Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com>
__read_mostly predates __ro_after_init. Many variables which are marked
__read_mostly should have been __ro_after_init from day 1.
Also, mark some stuff as "const" and "__init" while I'm at it.
[akpm@linux-foundation.org: revert sysctl_nr_open_min, sysctl_nr_open_max changes due to arm warning]
[akpm@linux-foundation.org: coding-style cleanups]
Link: https://lkml.kernel.org/r/4f6bb9c0-abba-4ee4-a7aa-89265e886817@p183
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Percpu counter's compare and add are separate functions: without locking
around them (which would defeat their purpose), it has been possible to
overflow the intended limit. Imagine all the other CPUs fallocating tmpfs
huge pages to the limit, in between this CPU's compare and its add.
I have not seen reports of that happening; but tmpfs's recent addition of
dquot_alloc_block_nodirty() in between the compare and the add makes it
even more likely, and I'd be uncomfortable to leave it unfixed.
Introduce percpu_counter_limited_add(fbc, limit, amount) to prevent it.
I believe this implementation is correct, and slightly more efficient than
the combination of compare and add (taking the lock once rather than twice
when nearing full - the last 128MiB of a tmpfs volume on a machine with
128 CPUs and 4KiB pages); but it does beg for a better design - when
nearing full, there is no new batching, but the costly percpu counter sum
across CPUs still has to be done, while locked.
Follow __percpu_counter_sum()'s example, including cpu_dying_mask as well
as cpu_online_mask: but shouldn't __percpu_counter_compare() and
__percpu_counter_limited_add() then be adding a num_dying_cpus() to
num_online_cpus(), when they calculate the maximum which could be held
across CPUs? But the times when it matters would be vanishingly rare.
Link: https://lkml.kernel.org/r/bb817848-2d19-bcc8-39ca-ea179af0f0b4@google.com
Signed-off-by: Hugh Dickins <hughd@google.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: Tim Chen <tim.c.chen@intel.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Carlos Maiolino <cem@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Users complained about OOM errors during fork without triggering
compaction. This can be fixed by modifying the flags used in
mas_expected_entries() so that the compaction will be triggered in low
memory situations. Since mas_expected_entries() is only used during fork,
the extra argument does not need to be passed through.
Additionally, the two test_maple_tree test cases and one benchmark test
were altered to use the correct locking type so that allocations would not
trigger sleeping and thus fail. Testing was completed with lockdep atomic
sleep detection.
The additional locking change requires rwsem support additions to the
tools/ directory through the use of pthreads pthread_rwlock_t. With this
change test_maple_tree works in userspace, as a module, and in-kernel.
Users may notice that the system gave up early on attempting to start new
processes instead of attempting to reclaim memory.
Link: https://lkml.kernel.org/r/20230915093243epcms1p46fa00bbac1ab7b7dca94acb66c44c456@epcms1p4
Link: https://lkml.kernel.org/r/20231012155233.2272446-1-Liam.Howlett@oracle.com
Fixes: 54a611b605 ("Maple Tree: add new data structure")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: <jason.sim@samsung.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Qualcomm driver updates for v6.7
This introduces partial support for the Qualcomm Secure Execution
Environment SCM interface, and uses this to implement EFI variable
access on the Windows On Snapdragon devices (for now).
The 32/64-bit calling convention detector of the SCM interface is
updated to not choose 64-bit convention when Linux is 32-bit. The
"extern" specifier is dropped from the interface include file.
The LLCC driver gains support for carrying configuration for multiple
different system/DDR configurations for a given platform, and selecting
between them. Support for Q[DR]U1000 is added to the driver.
All exported symbols are transitioned to EXPORT_SYMBOL_GPL().
The platform_drivers in the Qualcomm SoC are transitioned to the
void-returning remove_new implementation.
The rmtfs memory driver gains support for leaving guard pages around the
used area, to avoid issues if the allocation happens to be placed
adjacent to another protected memory region.
The socinfo driver gains knowledge about IPQ8174, QCM6490, SM7150P and
various PMICs used together with SM8550.
* tag 'qcom-drivers-for-6.7' of https://git.kernel.org/pub/scm/linux/kernel/git/qcom/linux: (44 commits)
soc: qcom: socinfo: Convert to platform remove callback returning void
soc: qcom: smsm: Convert to platform remove callback returning void
soc: qcom: smp2p: Convert to platform remove callback returning void
soc: qcom: smem: Convert to platform remove callback returning void
soc: qcom: rmtfs_mem: Convert to platform remove callback returning void
soc: qcom: qcom_stats: Convert to platform remove callback returning void
soc: qcom: qcom_gsbi: Convert to platform remove callback returning void
soc: qcom: qcom_aoss: Convert to platform remove callback returning void
soc: qcom: pmic_glink: Convert to platform remove callback returning void
soc: qcom: ocmem: Convert to platform remove callback returning void
soc: qcom: llcc-qcom: Convert to platform remove callback returning void
soc: qcom: icc-bwmon: Convert to platform remove callback returning void
firmware: qcom_scm: use 64-bit calling convention only when client is 64-bit
soc: qcom: llcc: Handle a second device without data corruption
soc: qcom: Switch to EXPORT_SYMBOL_GPL()
soc: qcom: smem: Annotate struct qcom_smem with __counted_by
soc: qcom: rmtfs: Support discarding guard pages
dt-bindings: reserved-memory: rmtfs: Allow guard pages
dt-bindings: firmware: qcom,scm: document IPQ5018 compatible
firmware: qcom_scm: disable SDI if required
...
Link: https://lore.kernel.org/r/20231015204014.855672-1-andersson@kernel.org
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The test_objpool module (test_objpool) will run several testcases
for objpool stress and performance evaluation. Each testcase will
have all available cpu cores involved to create a situation of high
parallel and high contention.
As of now there are 5 groups and 5 * 2 testcases in total:
1) group 1: synchronous mode
objpool is managed synchronously, that is, all objects are to be
reclaimed before objpool finalization and the objpool owner makes
sure of it. All threads on different cores run in the same pace
2) group 2: synchronous mode + hrtimer
this case have 2 customers: normal threads and hrtimer softirqs
3) group 3: synchronous + overrun mode
This test group is mainly for performance evaluation of missing
cases when pre-allocated objects are less than the requested
4) group 4: asynchronous mode
This case is just an emulation of kretprobe, with refcount used
to control the objpool lifecycle
5) group 5: asynchronous mode with hrtimer
hrtimer softirq is introduced to stress async objpool operations
Link: https://lore.kernel.org/all/20231017135654.82270-3-wuqiang.matt@bytedance.com/
Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
objpool is a scalable implementation of high performance queue for
object allocation and reclamation, such as kretprobe instances.
With leveraging percpu ring-array to mitigate hot spots of memory
contention, it delivers near-linear scalability for high parallel
scenarios. The objpool is best suited for the following cases:
1) Memory allocation or reclamation are prohibited or too expensive
2) Consumers are of different priorities, such as irqs and threads
Limitations:
1) Maximum objects (capacity) is fixed after objpool creation
2) All pre-allocated objects are managed in percpu ring array,
which consumes more memory than linked lists
Link: https://lore.kernel.org/all/20231017135654.82270-2-wuqiang.matt@bytedance.com/
Signed-off-by: wuqiang.matt <wuqiang.matt@bytedance.com>
Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
lwq is a FIFO single-linked queue that only requires a spinlock
for dequeueing, which happens in process context. Enqueueing is atomic
with no spinlock and can happen in any context.
This is particularly useful when work items are queued from BH or IRQ
context, and when they are handled one at a time by dedicated threads.
Avoiding any locking when enqueueing means there is no need to disable
BH or interrupts, which is generally best avoided (particularly when
there are any RT tasks on the machine).
This solution is superior to using "list_head" links because we need
half as many pointers in the data structures, and because list_head
lists would need locking to add items to the queue.
This solution is superior to a bespoke solution as all locking and
container_of casting is integrated, so the interface is simple.
Despite the similar name, this solution meets a distinctly different
need to kfifo. kfifo provides a fixed sized circular buffer to which
data can be added at one end and removed at the other, and does not
provide any locking. lwq does not have any size limit and works with
data structures (objects?) rather than data (bytes).
A unit test for basic functionality, which runs at boot time, is included.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: David Gow <davidgow@google.com>
Cc: linux-kernel@vger.kernel.org
Message-Id: <20230911111333.4d1a872330e924a00acb905b@linux-foundation.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
llist_del_first_this() deletes a specific entry from an llist, providing
it is at the head of the list. Multiple threads can call this
concurrently providing they each offer a different entry.
This can be uses for a set of worker threads which are on the llist when
they are idle. The head can always be woken, and when it is woken it
can remove itself, and possibly wake the next if there is an excess of
work to do.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
lib/bitmap.c and corresponding include/linux/bitmap.h are intended to
hold functions related to operations on bitmaps, like bitmap_shift or
bitmap_set. Historically, some string-related operations like
bitmap_parse are also reside in lib/bitmap.c.
Now that the subsystem evolves, string-related bitmap operations became a
significant part of the file. Because they are quite different from the
other bitmap functions by nature, it's worth to split them to a separate
source/header files.
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
CC: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Besides the fact it's not used anywhere it should be implemented
differently, i.e. via helpers from linux/byteorder/generic.h.
Yet the helpers themselves need to be introduced first.
Also note, the function lacks of the test cases, they must be provided.
Hence, drop the current dead code for good.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Clean up some punctutation and abbreviations.
Add kernel-doc notation for one function and function return value
for 39 functions.
cpumask.h:
Fix some punctuation (plural vs. possessive).
Fix some abbreviations (ie. -> i.e., id -> ID).
Fix 35 warnings like this:
include/linux/cpumask.h:161: warning: No description found for return value of 'cpumask_first'
cpumask.c:
Add Return: value for 4 functions.
Add kernel-doc for cpumask_any_distribute().
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Use atomic_try_cmpxchg() instead of atomic_cmpxchg(*ptr, old, new) == old
in rcuref_put_slowpath(). On x86 the CMPXCHG instruction returns success in the
ZF flag, so this change saves a compare after CMPXCHG. Additionaly,
the compiler reorders some code blocks to follow likely/unlikely
annotations in the atomic_try_cmpxchg() macro, improving the code from:
9a: f0 0f b1 0b lock cmpxchg %ecx,(%rbx)
9e: 83 f8 ff cmp $0xffffffff,%eax
a1: 74 04 je a7 <rcuref_put_slowpath+0x27>
a3: 31 c0 xor %eax,%eax
to:
9a: f0 0f b1 0b lock cmpxchg %ecx,(%rbx)
9e: 75 4c jne ec <rcuref_put_slowpath+0x6c>
a0: b0 01 mov $0x1,%al
No functional change intended.
Signed-off-by: Uros Bizjak <ubizjak@gmail.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Paul E. McKenney <paulmck@kernel.org>
Link: https://lore.kernel.org/r/20230509150255.3691-1-ubizjak@gmail.com
PowerPC has a 'btext' font used for the console which is almost identical
to the shared font_sun8x16, so use it rather than duplicating the data.
They were actually identical until about a decade ago when
commit bcfbeecea1 ("drivers: console: font_: Change a glyph from
"broken bar" to "vertical line"")
which changed the | in the shared font to be a solid
bar rather than a broken bar. That's the only difference.
This was originally spotted by the PMF source code analyser, which
noticed that sparc does the same thing with the same data, and they
also share a bunch of functions to manipulate the data. I've previously
posted a near identical patch for sparc.
Tested very lightly with a boot without FS in qemu.
Signed-off-by: "Dr. David Alan Gilbert" <linux@treblig.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20230825142754.1487900-1-linux@treblig.org
When updating the maple tree iterator to avoid rewalks, an issue was
introduced when shifting beyond the limits. This can be seen by trying to
go to the previous address of 0, which would set the maple node to
MAS_NONE and keep the range as the last entry.
Subsequent calls to mas_find() would then search upwards from mas->last
and skip the value at mas->index/mas->last. This showed up as a bug in
mprotect which skips the actual VMA at the current range after attempting
to go to the previous VMA from 0.
Since MAS_NONE may already be set when searching for a value that isn't
contained within a node, changing the handling of MAS_NONE in mas_find()
would make the code more complicated and error prone. Furthermore, there
was no way to tell which limit was hit, and thus which action to take
(next or the entry at the current range).
This solution is to add two states to track what happened with the
previous iterator action. This allows for the expected behaviour of the
next command to return the correct item (either the item at the range
requested, or the next/previous).
Tests are also added and updated accordingly.
Link: https://lkml.kernel.org/r/20230921181236.509072-3-Liam.Howlett@oracle.com
Link: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b
Link: https://lore.kernel.org/linux-mm/20230921181236.509072-1-Liam.Howlett@oracle.com/
Fixes: 39193685d5 ("maple_tree: try harder to keep active node with mas_prev()")
Signed-off-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reported-by: Pedro Falcato <pedro.falcato@gmail.com>
Closes: https://gist.github.com/heatd/85d2971fae1501b55b6ea401fbbe485b
Closes: https://bugs.archlinux.org/task/79656
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If the outer layer for loop is iterated more than once and it fails not
in the first iteration, the filtered_suite and filtered_suite->test_cases
allocated in the last kunit_filter_attr_tests() in last inner for loop
is leaked.
So add a new free_filtered_suite err label and free the filtered_suite
and filtered_suite->test_cases so far. And change kmalloc_array of copy
to kcalloc to Clear the copy to make the kfree safe.
Fixes: 529534e8cb ("kunit: Add ability to filter attributes")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
If the outer layer for loop is iterated more than once and it fails not
in the first iteration, the copy pointer has been moved. So it should free
the original copy's backup copy_start.
Fixes: abbf73816b ("kunit: fix possible memory leak in kunit_filter_suites()")
Signed-off-by: Jinjie Ruan <ruanjinjie@huawei.com>
Reviewed-by: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Describe missing function parameters to prevent kernel-doc warnings:
lib/scatterlist.c:288: warning: Function parameter or member 'first_chunk' not described in '__sg_alloc_table'
lib/scatterlist.c:800: warning: Function parameter or member 'flags' not described in 'sg_miter_start'
Link: https://lkml.kernel.org/r/20230912060848.4673-1-rdunlap@infradead.org
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
If we skip one parametrized test case then test status remains
SKIP for all subsequent test params leading to wrong reports:
$ ./tools/testing/kunit/kunit.py run \
--kunitconfig ./lib/kunit/.kunitconfig *.example_params*
--raw_output \
[ ] Starting KUnit Kernel (1/1)...
KTAP version 1
1..1
# example: initializing suite
KTAP version 1
# Subtest: example
# module: kunit_example_test
1..1
KTAP version 1
# Subtest: example_params_test
# example_params_test: initializing
# example_params_test: cleaning up
ok 1 example value 3 # SKIP unsupported param value 3
# example_params_test: initializing
# example_params_test: cleaning up
ok 2 example value 2 # SKIP unsupported param value 3
# example_params_test: initializing
# example_params_test: cleaning up
ok 3 example value 1 # SKIP unsupported param value 3
# example_params_test: initializing
# example_params_test: cleaning up
ok 4 example value 0 # SKIP unsupported param value 0
# example_params_test: pass:0 fail:0 skip:4 total:4
ok 1 example_params_test # SKIP unsupported param value 0
# example: exiting suite
ok 1 example # SKIP
Reset test status and status comment after each param iteration
to avoid using stale results.
Signed-off-by: Michal Wajdeczko <michal.wajdeczko@intel.com>
Cc: David Gow <davidgow@google.com>
Cc: Rae Moar <rmoar@google.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Add a test of the speed and memory use of string_stream.
string_stream_performance_test() doesn't actually "test" anything (it
cannot fail unless the system has run out of allocatable memory) but it
measures the speed and memory consumption of the string_stream and reports
the result.
This allows changes in the string_stream implementation to be compared.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Replace the fixed-size log buffer with a string_stream so that the
log can grow as lines are added.
The existing kunit log tests have been updated for using a
string_stream as the log. No new test have been added because there
are already tests for the underlying string_stream.
As the log tests now depend on string_stream functions they cannot
build when kunit-test is a module. They have been surrounded by
a #if to replace them with skipping version when the test is
build as a module. Though this isn't pretty, it avoids moving
code to another file while that code is also being changed.
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
string_stream_managed_free_test() allocates a resource-managed
string_stream and tests that kunit_free_string_stream() calls
string_stream_destroy().
string_stream_resource_free_test() allocates a resource-managed
string_stream and tests that string_stream_destroy() is called
when the test resources are cleaned up.
The old string_stream_init_test() has been split into two tests,
one for kunit_alloc_string_stream() and the other for
alloc_string_stream().
Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com>
Reviewed-by: David Gow <davidgow@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
