The main intent here is to get rid of the iio_buffer_set_attrs() helper, or
at least rework it's usage a bit.
The problem with that helper is that it needs a pointer to the buffer,
which makes supporting multiple buffers per IIO device a bit more
cumbersome.
The hid_sensor_setup_trigger() is pretty much used in the same way:
- iio_triggered_buffer_setup() gets called before
- then hid_sensor_setup_trigger() and hid_sensor_setup_batch_mode() gets
called which may attach some fifo attributes
This change merges the 2 together under the hid_sensor_setup_trigger()
function. Only the &iio_pollfunc_store_time is passed to all devices, so
it's not even required to pass it explicitly outside of the common
hid_sensor_setup_trigger() function.
Moving the devm_iio_triggered_buffer_setup/cleanup() calls into the common
place code can help the rework of the buffer code, since it is in one
place.
One detail of the change is that there are 2 drivers that use
devm_iio_triggered_buffer_setup(). That function gets implicitly
replaced with iio_triggered_buffer_setup()/cleanup(), but since all drivers
call both hid_sensor_setup_trigger9) & hid_sensor_remove_trigger() trigger,
the iio_triggered_buffer_cleanup() piggy backs on the
hid_sensor_remove_trigger() call, which should cover the cleanup.
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@analog.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This adds a new driver for the Cypress CY8CTMA140 touchscreen.
This driver is inspired by out-of-tree code for the Samsung
GT-S7710 mobile phone.
I have tried to compare the structure and behaviour of this
touchscreen to the existing CYTTSP and CYTTSP4 generics and
it seems pretty different. It is also different in character
from the cy8ctmg110_ts.c. It appears to rather be vaguely
related to the Melfas MMS114 driver, yet distinctly
different.
Dmitry Torokhov rewrote the key scanning code during the
submission process so the driver is a joint work.
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20200506123435.187432-2-linus.walleij@linaro.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20200507185347.GA14499@embeddedor
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
In the current codes, the octeontx2 uses its own method to allocate
the pool buffers, but there are some issues in this implementation.
1. We have to run the otx2_get_page() for each allocation cycle and
this is pretty error prone. As I can see there is no invocation
of the otx2_get_page() in otx2_pool_refill_task(), this will leave
the allocated pages have the wrong refcount and may be freed wrongly.
2. It wastes memory. For example, if we only receive one packet in a
NAPI RX cycle, and then allocate a 2K buffer with otx2_alloc_rbuf()
to refill the pool buffers and leave the remain area of the allocated
page wasted. On a kernel with 64K page, 62K area is wasted.
IMHO it is really unnecessary to implement our own method for the
buffers allocate, we can reuse the napi_alloc_frag() to simplify
our code.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If systemd is configured to use hybrid mode which enables the use of
both cgroup v1 and v2, systemd will create new cgroup on both the default
root (v2) and netprio_cgroup hierarchy (v1) for a new session and attach
task to the two cgroups. If the task does some network thing then the v2
cgroup can never be freed after the session exited.
One of our machines ran into OOM due to this memory leak.
In the scenario described above when sk_alloc() is called
cgroup_sk_alloc() thought it's in v2 mode, so it stores
the cgroup pointer in sk->sk_cgrp_data and increments
the cgroup refcnt, but then sock_update_netprioidx()
thought it's in v1 mode, so it stores netprioidx value
in sk->sk_cgrp_data, so the cgroup refcnt will never be freed.
Currently we do the mode switch when someone writes to the ifpriomap
cgroup control file. The easiest fix is to also do the switch when
a task is attached to a new cgroup.
Fixes: bd1060a1d6 ("sock, cgroup: add sock->sk_cgroup")
Reported-by: Yang Yingliang <yangyingliang@huawei.com>
Tested-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Zefan Li <lizefan@huawei.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The current codebase makes use of the zero-length array language
extension to the C90 standard, but the preferred mechanism to declare
variable-length types such as these ones is a flexible array member[1][2],
introduced in C99:
struct foo {
int stuff;
struct boo array[];
};
By making use of the mechanism above, we will get a compiler warning
in case the flexible array does not occur last in the structure, which
will help us prevent some kind of undefined behavior bugs from being
inadvertently introduced[3] to the codebase from now on.
Also, notice that, dynamic memory allocations won't be affected by
this change:
"Flexible array members have incomplete type, and so the sizeof operator
may not be applied. As a quirk of the original implementation of
zero-length arrays, sizeof evaluates to zero."[1]
sizeof(flexible-array-member) triggers a warning because flexible array
members have incomplete type[1]. There are some instances of code in
which the sizeof operator is being incorrectly/erroneously applied to
zero-length arrays and the result is zero. Such instances may be hiding
some bugs. So, this work (flexible-array member conversions) will also
help to get completely rid of those sorts of issues.
This issue was found with the help of Coccinelle.
[1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html
[2] https://github.com/KSPP/linux/issues/21
[3] commit 7649773293 ("cxgb3/l2t: Fix undefined behaviour")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
runqslower doesn't specify include path for uapi/bpf.h. This causes the
following warning:
In file included from runqslower.c:10:
.../tools/testing/selftests/bpf/tools/include/bpf/bpf.h:234:38:
warning: 'enum bpf_stats_type' declared inside parameter list will not
be visible outside of this definition or declaration
234 | LIBBPF_API int bpf_enable_stats(enum bpf_stats_type type);
Fix this by adding -I tools/includ/uapi to the Makefile.
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Song Liu <songliubraving@fb.com>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
It seems that for whatever reason, gcc-10 ends up not inlining a couple
of functions that used to be inlined before. Even if they only have one
single callsite - it looks like gcc may have decided that the code was
unlikely, and not worth inlining.
The code generation difference is harmless, but caused a few new section
mismatch errors, since the (now no longer inlined) function wasn't in
the __init section, but called other init functions:
Section mismatch in reference from the function kexec_free_initrd() to the function .init.text:free_initrd_mem()
Section mismatch in reference from the function tpm2_calc_event_log_size() to the function .init.text:early_memremap()
Section mismatch in reference from the function tpm2_calc_event_log_size() to the function .init.text:early_memunmap()
So add the appropriate __init annotation to make modpost not complain.
In both cases there were trivially just a single callsite from another
__init function.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ROHM BD99954 is a Battery Management LSI for 1-4 cell Lithium-Ion
secondary battery intended to be used in space-constraint equipment such
as Low profile Notebook PC, Tablets and other applications. BD99954
provides a Dual-source Battery Charger, two port BC1.2 detection and a
Battery Monitor.
Support ROHM BD99954 Charger IC.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
The ROHM BD99954 is a Battery Management LSI for 1-4 cell Lithium-Ion
secondary battery. Intended to be used in space-constraint equipment such
as Low profile Notebook PC, Tablets and other applications. BD99954
provides a Dual-source Battery Charger, two port BC1.2 detection and a
Battery Monitor.
Document the DT bindings for BD99954
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Add:
- trickle-charge-current-microamp:
Some chargers have 3 charging stages. First one when battery is almost
empty is often called as trickle-charge. Last state when battery has been
"woken up" is usually called as fast-charge. In addition to this some
chargers have a 'middle state' which ROHM BD99954 data-sheet describes as
pre-charge. Some batteries can benefit from this 3-phase charging
[citation needed].
Introduce trickle-charge-current-microamp so that batteries can give
charging current limit for all three states.
- precharge-upper-limit-microvolt:
When battery voltage has reached certain limit we change from
trickle-charge to next charging state (pre-charge for BD99954). Allow
battery to specify this limit.
- re-charge-voltage-microvolt:
Allow giving a battery specific voltage limit for chargers which can
automatically re-start charging when battery has discharghed down to
this limit.
- over-voltage-threshold-microvolt
Allow specifying voltage threshold after which the battery is assumed to
be faulty.
Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Yonghong Song says:
====================
Motivation:
The current way to dump kernel data structures mostly:
1. /proc system
2. various specific tools like "ss" which requires kernel support.
3. drgn
The dropback for the first two is that whenever you want to dump more, you
need change the kernel. For example, Martin wants to dump socket local
storage with "ss". Kernel change is needed for it to work ([1]).
This is also the direct motivation for this work.
drgn ([2]) solves this proble nicely and no kernel change is not needed.
But since drgn is not able to verify the validity of a particular pointer value,
it might present the wrong results in rare cases.
In this patch set, we introduce bpf iterator. Initial kernel changes are
still needed for interested kernel data, but a later data structure change
will not require kernel changes any more. bpf program itself can adapt
to new data structure changes. This will give certain flexibility with
guaranteed correctness.
In this patch set, kernel seq_ops is used to facilitate iterating through
kernel data, similar to current /proc and many other lossless kernel
dumping facilities. In the future, different iterators can be
implemented to trade off losslessness for other criteria e.g. no
repeated object visits, etc.
User Interface:
1. Similar to prog/map/link, the iterator can be pinned into a
path within a bpffs mount point.
2. The bpftool command can pin an iterator to a file
bpftool iter pin <bpf_prog.o> <path>
3. Use `cat <path>` to dump the contents.
Use `rm -f <path>` to remove the pinned iterator.
4. The anonymous iterator can be created as well.
Please see patch #19 andd #20 for bpf programs and bpf iterator
output examples.
Note that certain iterators are namespace aware. For example,
task and task_file targets only iterate through current pid namespace.
ipv6_route and netlink will iterate through current net namespace.
Please see individual patches for implementation details.
Performance:
The bpf iterator provides in-kernel aggregation abilities
for kernel data. This can greatly improve performance
compared to e.g., iterating all process directories under /proc.
For example, I did an experiment on my VM with an application forking
different number of tasks and each forked process opening various number
of files. The following is the result with the latency with unit of microseconds:
# of forked tasks # of open files # of bpf_prog calls # latency (us)
100 100 11503 7586
1000 1000 1013203 709513
10000 100 1130203 764519
The number of bpf_prog calls may be more than forked tasks multipled by
open files since there are other tasks running on the system.
The bpf program is a do-nothing program. One millions of bpf calls takes
less than one second.
Although the initial motivation is from Martin's sk_local_storage,
this patch didn't implement tcp6 sockets and sk_local_storage.
The /proc/net/tcp6 involves three types of sockets, timewait,
request and tcp6 sockets. Some kind of type casting or other
mechanism is needed to handle all these socket types in one
bpf program. This will be addressed in future work.
Currently, we do not support kernel data generated under module.
This requires some BTF work.
More work for more iterators, e.g., tcp, udp, bpf_map elements, etc.
Changelog:
v3 -> v4:
- in bpf_seq_read(), if start() failed with an error, return that
error to user space (Andrii)
- in bpf_seq_printf(), if reading kernel memory failed for
%s and %p{i,I}{4,6}, set buffer to empty string or address 0.
Documented this behavior in uapi header (Andrii)
- fix a few error handling issues for bpftool (Andrii)
- A few other minor fixes and cosmetic changes.
v2 -> v3:
- add bpf_iter_unreg_target() to unregister a target, used in the
error path of the __init functions.
- handle err != 0 before handling overflow (Andrii)
- reference count "task" for task_file target (Andrii)
- remove some redundancy for bpf_map/task/task_file targets
- add bpf_iter_unreg_target() in ip6_route_cleanup()
- Handling "%%" format in bpf_seq_printf() (Andrii)
- implement auto-attach for bpf_iter in libbpf (Andrii)
- add macros offsetof and container_of in bpf_helpers.h (Andrii)
- add tests for auto-attach and program-return-1 cases
- some other minor fixes
v1 -> v2:
- removed target_feature, using callback functions instead
- checking target to ensure program specified btf_id supported (Martin)
- link_create change with new changes from Andrii
- better handling of btf_iter vs. seq_file private data (Martin, Andrii)
- implemented bpf_seq_read() (Andrii, Alexei)
- percpu buffer for bpf_seq_printf() (Andrii)
- better syntax for BPF_SEQ_PRINTF macro (Andrii)
- bpftool fixes (Quentin)
- a lot of other fixes
RFC v2 -> v1:
- rename bpfdump to bpf_iter
- use bpffs instead of a new file system
- use bpf_link to streamline and simplify iterator creation.
References:
[1]: https://lore.kernel.org/bpf/20200225230427.1976129-1-kafai@fb.com
[2]: https://github.com/osandov/drgn
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The added test includes the following subtests:
- test verifier change for btf_id_or_null
- test load/create_iter/read for
ipv6_route/netlink/bpf_map/task/task_file
- test anon bpf iterator
- test anon bpf iterator reading one char at a time
- test file bpf iterator
- test overflow (single bpf program output not overflow)
- test overflow (single bpf program output overflows)
- test bpf prog returning 1
The ipv6_route tests the following verifier change
- access fields in the variable length array of the structure.
The netlink load tests the following verifier change
- put a btf_id ptr value in a stack and accessible to
tracing/iter programs.
The anon bpf iterator also tests link auto attach through skeleton.
$ test_progs -n 2
#2/1 btf_id_or_null:OK
#2/2 ipv6_route:OK
#2/3 netlink:OK
#2/4 bpf_map:OK
#2/5 task:OK
#2/6 task_file:OK
#2/7 anon:OK
#2/8 anon-read-one-char:OK
#2/9 file:OK
#2/10 overflow:OK
#2/11 overflow-e2big:OK
#2/12 prog-ret-1:OK
#2 bpf_iter:OK
Summary: 1/12 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175923.2477637-1-yhs@fb.com
The implementation is arbitrary, just to show how the bpf programs
can be written for bpf_map/task/task_file. They can be costomized
for specific needs.
For example, for bpf_map, the iterator prints out:
$ cat /sys/fs/bpf/my_bpf_map
id refcnt usercnt locked_vm
3 2 0 20
6 2 0 20
9 2 0 20
12 2 0 20
13 2 0 20
16 2 0 20
19 2 0 20
%%% END %%%
For task, the iterator prints out:
$ cat /sys/fs/bpf/my_task
tgid gid
1 1
2 2
....
1944 1944
1948 1948
1949 1949
1953 1953
=== END ===
For task/file, the iterator prints out:
$ cat /sys/fs/bpf/my_task_file
tgid gid fd file
1 1 0 ffffffff95c97600
1 1 1 ffffffff95c97600
1 1 2 ffffffff95c97600
....
1895 1895 255 ffffffff95c8fe00
1932 1932 0 ffffffff95c8fe00
1932 1932 1 ffffffff95c8fe00
1932 1932 2 ffffffff95c8fe00
1932 1932 3 ffffffff95c185c0
This is able to print out all open files (fd and file->f_op), so user can compare
f_op against a particular kernel file operations to find what it is.
For example, from /proc/kallsyms, we can find
ffffffff95c185c0 r eventfd_fops
so we will know tgid 1932 fd 3 is an eventfd file descriptor.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175922.2477576-1-yhs@fb.com
Currently, only one command is supported
bpftool iter pin <bpf_prog.o> <path>
It will pin the trace/iter bpf program in
the object file <bpf_prog.o> to the <path>
where <path> should be on a bpffs mount.
For example,
$ bpftool iter pin ./bpf_iter_ipv6_route.o \
/sys/fs/bpf/my_route
User can then do a `cat` to print out the results:
$ cat /sys/fs/bpf/my_route
fe800000000000000000000000000000 40 00000000000000000000000000000000 ...
00000000000000000000000000000000 00 00000000000000000000000000000000 ...
00000000000000000000000000000001 80 00000000000000000000000000000000 ...
fe800000000000008c0162fffebdfd57 80 00000000000000000000000000000000 ...
ff000000000000000000000000000000 08 00000000000000000000000000000000 ...
00000000000000000000000000000000 00 00000000000000000000000000000000 ...
The implementation for ipv6_route iterator is in one of subsequent
patches.
This patch also added BPF_LINK_TYPE_ITER to link query.
In the future, we may add additional parameters to pin command
by parameterizing the bpf iterator. For example, a map_id or pid
may be added to let bpf program only traverses a single map or task,
similar to kernel seq_file single_open().
We may also add introspection command for targets/iterators by
leveraging the bpf_iter itself.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20200509175920.2477247-1-yhs@fb.com
Two new libbpf APIs are added to support bpf_iter:
- bpf_program__attach_iter
Given a bpf program and additional parameters, which is
none now, returns a bpf_link.
- bpf_iter_create
syscall level API to create a bpf iterator.
The macro BPF_SEQ_PRINTF are also introduced. The format
looks like:
BPF_SEQ_PRINTF(seq, "task id %d\n", pid);
This macro can help bpf program writers with
nicer bpf_seq_printf syntax similar to the kernel one.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175917.2476936-1-yhs@fb.com
Two helpers bpf_seq_printf and bpf_seq_write, are added for
writing data to the seq_file buffer.
bpf_seq_printf supports common format string flag/width/type
fields so at least I can get identical results for
netlink and ipv6_route targets.
For bpf_seq_printf and bpf_seq_write, return value -EOVERFLOW
specifically indicates a write failure due to overflow, which
means the object will be repeated in the next bpf invocation
if object collection stays the same. Note that if the object
collection is changed, depending how collection traversal is
done, even if the object still in the collection, it may not
be visited.
For bpf_seq_printf, format %s, %p{i,I}{4,6} needs to
read kernel memory. Reading kernel memory may fail in
the following two cases:
- invalid kernel address, or
- valid kernel address but requiring a major fault
If reading kernel memory failed, the %s string will be
an empty string and %p{i,I}{4,6} will be all 0.
Not returning error to bpf program is consistent with
what bpf_trace_printk() does for now.
bpf_seq_printf may return -EBUSY meaning that internal percpu
buffer for memory copy of strings or other pointees is
not available. Bpf program can return 1 to indicate it
wants the same object to be repeated. Right now, this should not
happen on no-RT kernels since migrate_disable(), which guards
bpf prog call, calls preempt_disable().
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175914.2476661-1-yhs@fb.com
Add bpf_reg_type PTR_TO_BTF_ID_OR_NULL support.
For tracing/iter program, the bpf program context
definition, e.g., for previous bpf_map target, looks like
struct bpf_iter__bpf_map {
struct bpf_iter_meta *meta;
struct bpf_map *map;
};
The kernel guarantees that meta is not NULL, but
map pointer maybe NULL. The NULL map indicates that all
objects have been traversed, so bpf program can take
proper action, e.g., do final aggregation and/or send
final report to user space.
Add btf_id_or_null_non0_off to prog->aux structure, to
indicate that if the context access offset is not 0,
set to PTR_TO_BTF_ID_OR_NULL instead of PTR_TO_BTF_ID.
This bit is set for tracing/iter program.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175912.2476576-1-yhs@fb.com
Only the tasks belonging to "current" pid namespace
are enumerated.
For task/file target, the bpf program will have access to
struct task_struct *task
u32 fd
struct file *file
where fd/file is an open file for the task.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175911.2476407-1-yhs@fb.com
This patch added netlink and ipv6_route targets, using
the same seq_ops (except show() and minor changes for stop())
for /proc/net/{netlink,ipv6_route}.
The net namespace for these targets are the current net
namespace at file open stage, similar to
/proc/net/{netlink,ipv6_route} reference counting
the net namespace at seq_file open stage.
Since module is not supported for now, ipv6_route is
supported only if the IPV6 is built-in, i.e., not compiled
as a module. The restriction can be lifted once module
is properly supported for bpf_iter.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175910.2476329-1-yhs@fb.com
Macro DEFINE_BPF_ITER_FUNC is implemented so target
can define an init function to capture the BTF type
which represents the target.
The bpf_iter_meta is a structure holding meta data, common
to all targets in the bpf program.
Additional marker functions are called before or after
bpf_seq_read() show()/next()/stop() callback functions
to help calculate precise seq_num and whether call bpf_prog
inside stop().
Two functions, bpf_iter_get_info() and bpf_iter_run_prog(),
are implemented so target can get needed information from
bpf_iter infrastructure and can run the program.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175907.2475956-1-yhs@fb.com
A new bpf command BPF_ITER_CREATE is added.
The anonymous bpf iterator is seq_file based.
The seq_file private data are referenced by targets.
The bpf_iter infrastructure allocated additional space
at seq_file->private before the space used by targets
to store some meta data, e.g.,
prog: prog to run
session_id: an unique id for each opened seq_file
seq_num: how many times bpf programs are queried in this session
done_stop: an internal state to decide whether bpf program
should be called in seq_ops->stop() or not
The seq_num will start from 0 for valid objects.
The bpf program may see the same seq_num more than once if
- seq_file buffer overflow happens and the same object
is retried by bpf_seq_read(), or
- the bpf program explicitly requests a retry of the
same object
Since module is not supported for bpf_iter, all target
registeration happens at __init time, so there is no
need to change bpf_iter_unreg_target() as it is used
mostly in error path of the init function at which time
no bpf iterators have been created yet.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175905.2475770-1-yhs@fb.com
bpf iterator uses seq_file to provide a lossless
way to transfer data to user space. But we want to call
bpf program after all objects have been traversed, and
bpf program may write additional data to the
seq_file buffer. The current seq_read() does not work
for this use case.
Besides allowing stop() function to write to the buffer,
the bpf_seq_read() also fixed the buffer size to one page.
If any single call of show() or stop() will emit data
more than one page to cause overflow, -E2BIG error code
will be returned to user space.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175904.2475468-1-yhs@fb.com
Given a bpf program, the step to create an anonymous bpf iterator is:
- create a bpf_iter_link, which combines bpf program and the target.
In the future, there could be more information recorded in the link.
A link_fd will be returned to the user space.
- create an anonymous bpf iterator with the given link_fd.
The bpf_iter_link can be pinned to bpffs mount file system to
create a file based bpf iterator as well.
The benefit to use of bpf_iter_link:
- using bpf link simplifies design and implementation as bpf link
is used for other tracing bpf programs.
- for file based bpf iterator, bpf_iter_link provides a standard
way to replace underlying bpf programs.
- for both anonymous and free based iterators, bpf link query
capability can be leveraged.
The patch added support of tracing/iter programs for BPF_LINK_CREATE.
A new link type BPF_LINK_TYPE_ITER is added to facilitate link
querying. Currently, only prog_id is needed, so there is no
additional in-kernel show_fdinfo() and fill_link_info() hook
is needed for BPF_LINK_TYPE_ITER link.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175901.2475084-1-yhs@fb.com
A bpf_iter program is a tracing program with attach type
BPF_TRACE_ITER. The load attribute
attach_btf_id
is used by the verifier against a particular kernel function,
which represents a target, e.g., __bpf_iter__bpf_map
for target bpf_map which is implemented later.
The program return value must be 0 or 1 for now.
0 : successful, except potential seq_file buffer overflow
which is handled by seq_file reader.
1 : request to restart the same object
In the future, other return values may be used for filtering or
teminating the iterator.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175900.2474947-1-yhs@fb.com
The target can call bpf_iter_reg_target() to register itself.
The needed information:
target: target name
seq_ops: the seq_file operations for the target
init_seq_private target callback to initialize seq_priv during file open
fini_seq_private target callback to clean up seq_priv during file release
seq_priv_size: the private_data size needed by the seq_file
operations
The target name represents a target which provides a seq_ops
for iterating objects.
The target can provide two callback functions, init_seq_private
and fini_seq_private, called during file open/release time.
For example, /proc/net/{tcp6, ipv6_route, netlink, ...}, net
name space needs to be setup properly during file open and
released properly during file release.
Function bpf_iter_unreg_target() is also implemented to unregister
a particular target.
Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200509175859.2474669-1-yhs@fb.com
lib: Add linear ranges helper library and start using it
Series extracts a "linear ranges" helper out of the regulator
framework. Linear ranges helper is intended to help converting
real-world values to register values when conversion is linear. I
suspect this is useful also for power subsystem and possibly for clk.
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Pull RISC-V fixes from Palmer Dabbelt:
"A smattering of fixes and cleanups:
- Dead code removal.
- Exporting riscv_cpuid_to_hartid_mask for modules.
- Per-CPU tracking of ISA features.
- Setting max_pfn correctly when probing memory.
- Adding a note to the VDSO so glibc can check the kernel's version
without a uname().
- A fix to force the bootloader to initialize the boot spin tables,
which still get used as a fallback when SBI-0.1 is enabled"
* tag 'riscv-for-linus-5.7-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
RISC-V: Remove unused code from STRICT_KERNEL_RWX
riscv: force __cpu_up_ variables to put in data section
riscv: add Linux note to vdso
riscv: set max_pfn to the PFN of the last page
RISC-V: Remove N-extension related defines
RISC-V: Add bitmap reprensenting ISA features common across CPUs
RISC-V: Export riscv_cpuid_to_hartid_mask() API
Fix gcc '-Wunused-but-set-variable' warning:
drivers/power/reset/ltc2952-poweroff.c:97:16: warning: variable
‘overruns’ set but not used [-Wunused-but-set-variable]
unsigned long overruns;
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Hongbo Yao <yaohongbo@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
In the probe function, in case of error, resources allocated in
'lp8788_setup_adc_channel()' must be released.
This can be achieved easily by using the devm_ variant of
'iio_channel_get()'.
This has the extra benefit to simplify the remove function and to axe the
'lp8788_release_adc_channel()' function which is now useless.
Fixes: 98a2766493 ("power_supply: Add new lp8788 charger driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Ido Schimmel says:
====================
mlxsw: spectrum: Enforce some HW limitations for matchall TC offload
Jiri says:
There are some limitations for TC matchall classifier offload that are
given by the mlxsw HW dataplane. It is not possible to do sampling on
egress and also the mirror/sample vs. ACL (flower) ordering is fixed. So
check this and forbid to offload incorrect setup.
====================
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Make sure that the drive restricts incorrect order of inserted matchall
vs. flower rules.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Check that matchall rules with sample actions are not possible to be
inserted to egress.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The file is about to contain matchall restrictions too, so change the
name to make it more generic.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On ingress, the matchall rules doing mirroring and sampling are offloaded
into hardware blocks that are processed before any flower rules.
On egress, the matchall mirroring rules are offloaded into hardware
block that is processed after all flower rules.
Therefore check the priorities of inserted flower rules against
existing matchall rules and ensure the correct ordering.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
On ingress, the matchall rules doing mirroring and sampling are offloaded
into hardware blocks that are processed before any flower rules.
On egress, the matchall mirroring rules are offloaded into hardware
block that is processed after all flower rules.
Therefore check the priorities of inserted matchall rules against
existing flower rules and ensure the correct ordering.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce an infrastructure that allows to get minimum and maximum
rule priority for specified chain. This is going to be used by
a subsequent patch to enforce ordering between flower and
matchall filters.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As there are going to be other matchall specific fields in flow
structure, put the existing list field into matchall substruct.
Signed-off-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: Ido Schimmel <idosch@mellanox.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
