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Lorenzo Bianconi [Thu, 9 Mar 2023 17:32:40 +0000 (18:32 +0100)]
selftests/bpf: Use ifname instead of ifindex in XDP compliance test tool
Rely on interface name instead of interface index in error messages or
logs from XDP compliance test tool.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/7dc5a8ff56c252b1a7ae29b059d0b2b1543c8b5d.1678382940.git.lorenzo@kernel.org
Michael Weiß [Thu, 9 Mar 2023 13:38:23 +0000 (14:38 +0100)]
bpf: Fix a typo for BPF_F_ANY_ALIGNMENT in bpf.h
Fix s/BPF_PROF_LOAD/BPF_PROG_LOAD/ typo in the documentation comment
for BPF_F_ANY_ALIGNMENT in bpf.h.
Signed-off-by: Michael Weiß <michael.weiss@aisec.fraunhofer.de>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230309133823.944097-1-michael.weiss@aisec.fraunhofer.de
Martin KaFai Lau [Thu, 9 Mar 2023 06:02:44 +0000 (22:02 -0800)]
selftests/bpf: Fix flaky fib_lookup test
There is a report that fib_lookup test is flaky when running in parallel.
A symptom of slowness or delay. An example:
Testing IPv6 stale neigh
set_lookup_params:PASS:inet_pton(IPV6_IFACE_ADDR) 0 nsec
test_fib_lookup:PASS:bpf_prog_test_run_opts 0 nsec
test_fib_lookup:FAIL:fib_lookup_ret unexpected fib_lookup_ret: actual 0 != expected 7
test_fib_lookup:FAIL:dmac not match unexpected dmac not match: actual 1 != expected 0
dmac expected 11:11:11:11:11:11 actual 00:00:00:00:00:00
[ Note that the "fib_lookup_ret unexpected fib_lookup_ret actual 0 ..."
is reversed in terms of expected and actual value. Fixing in this
patch also. ]
One possibility is the testing stale neigh entry was marked dead by the
gc (in neigh_periodic_work). The default gc_stale_time sysctl is 60s.
This patch increases it to 15 mins.
It also:
- fixes the reversed arg (actual vs expected) in one of the
ASSERT_EQ test
- removes the nodad command arg when adding v4 neigh entry which
currently has a warning.
Fixes:
168de0233586 ("selftests/bpf: Add bpf_fib_lookup test")
Reported-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230309060244.3242491-1-martin.lau@linux.dev
Alexei Starovoitov [Thu, 9 Mar 2023 00:19:51 +0000 (16:19 -0800)]
Merge branch 'BPF open-coded iterators'
Andrii Nakryiko says:
====================
Add support for open-coded (aka inline) iterators in BPF world. This is a next
evolution of gradually allowing more powerful and less restrictive looping and
iteration capabilities to BPF programs.
We set up a framework for implementing all kinds of iterators (e.g., cgroup,
task, file, etc, iterators), but this patch set only implements numbers
iterator, which is used to implement ergonomic bpf_for() for-like construct
(see patches #4-#5). We also add bpf_for_each(), which is a generic
foreach-like construct that will work with any kind of open-coded iterator
implementation, as long as we stick with bpf_iter_<type>_{new,next,destroy}()
naming pattern (which we now enforce on the kernel side).
Patch #1 is preparatory refactoring for easier way to check for special kfunc
calls. Patch #2 is adding iterator kfunc registration and validation logic,
which is mostly independent from the rest of open-coded iterator logic, so is
separated out for easier reviewing.
The meat of verifier-side logic is in patch #3. Patch #4 implements numbers
iterator. I kept them separate to have clean reference for how to integrate
new iterator types (now even simpler to do than in v1 of this patch set).
Patch #5 adds bpf_for(), bpf_for_each(), and bpf_repeat() macros to
bpf_misc.h, and also adds yet another pyperf test variant, now with bpf_for()
loop. Patch #6 is verification tests, based on numbers iterator (as the only
available right now). Patch #7 actually tests runtime behavior of numbers
iterator.
Finally, with changes in v2, it's possible and trivial to implement custom
iterators completely in kernel modules, which we showcase and test by adding
a simple iterator returning same number a given number of times to
bpf_testmod. Patch #8 is where all this happens and is tested.
Most of the relevant details are in corresponding commit messages or code
comments.
v4->v5:
- fixing missed inner for() in is_iter_reg_valid_uninit, and fixed return
false (kernel test robot);
- typo fixes and comment/commit description improvements throughout the
patch set;
v3->v4:
- remove unused variable from is_iter_reg_valid_init (kernel test robot);
v2->v3:
- remove special kfunc leftovers for bpf_iter_num_{new,next,destroy};
- add iters/testmod_seq* to DENYLIST.s390x, it doesn't support kfuncs in
modules yet (CI);
v1->v2:
- rebased on latest, dropping previously landed preparatory patches;
- each iterator type now have its own `struct bpf_iter_<type>` which allows
each iterator implementation to use exactly as much stack space as
necessary, allowing to avoid runtime allocations (Alexei);
- reworked how iterator kfuncs are defined, no verifier changes are required
when adding new iterator type;
- added bpf_testmod-based iterator implementation;
- address the rest of feedback, comments, commit message adjustment, etc.
Cc: Tejun Heo <tj@kernel.org>
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:21 +0000 (10:41 -0800)]
selftests/bpf: implement and test custom testmod_seq iterator
Implement a trivial iterator returning same specified integer value
N times as part of bpf_testmod kernel module. Add selftests to validate
everything works end to end.
We also reuse these tests as "verification-only" tests to validate that
kernel prints the state of custom kernel module-defined iterator correctly:
fp-16=iter_testmod_seq(ref_id=1,state=drained,depth=0)
"testmod_seq" part is an iterator type, and is coming from module's BTF
data dynamically at runtime.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:20 +0000 (10:41 -0800)]
selftests/bpf: add number iterator tests
Add number iterator (bpf_iter_num_{new,next,destroy}()) tests,
validating the correct handling of various corner and common cases
*at runtime*.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:19 +0000 (10:41 -0800)]
selftests/bpf: add iterators tests
Add various tests for open-coded iterators. Some of them excercise
various possible coding patterns in C, some go down to low-level
assembly for more control over various conditions, especially invalid
ones.
We also make use of bpf_for(), bpf_for_each(), bpf_repeat() macros in
some of these tests.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:18 +0000 (10:41 -0800)]
selftests/bpf: add bpf_for_each(), bpf_for(), and bpf_repeat() macros
Add bpf_for_each(), bpf_for(), and bpf_repeat() macros that make writing
open-coded iterator-based loops much more convenient and natural. These
macros utilize cleanup attribute to ensure proper destruction of the
iterator and thanks to that manage to provide the ergonomics that is
very close to C language's for() construct. Typical loop would look like:
int i;
int arr[N];
bpf_for(i, 0, N) {
/* verifier will know that i >= 0 && i < N, so could be used to
* directly access array elements with no extra checks
*/
arr[i] = i;
}
bpf_repeat() is very similar, but it doesn't expose iteration number and
is meant as a simple "repeat action N times" loop:
bpf_repeat(N) { /* whatever, N times */ }
Note that `break` and `continue` statements inside the {} block work as
expected.
bpf_for_each() is a generalization over any kind of BPF open-coded
iterator allowing to use for-each-like approach instead of calling
low-level bpf_iter_<type>_{new,next,destroy}() APIs explicitly. E.g.:
struct cgroup *cg;
bpf_for_each(cgroup, cg, some, input, args) {
/* do something with each cg */
}
would call (not-yet-implemented) bpf_iter_cgroup_{new,next,destroy}()
functions to form a loop over cgroups, where `some, input, args` are
passed verbatim into constructor as
bpf_iter_cgroup_new(&it, some, input, args).
As a first demonstration, add pyperf variant based on the bpf_for() loop.
Also clean up a few tests that either included bpf_misc.h header
unnecessarily from the user-space, which is unsupported, or included it
before any common types are defined (and thus leading to unnecessary
compilation warnings, potentially).
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:17 +0000 (10:41 -0800)]
bpf: implement numbers iterator
Implement the first open-coded iterator type over a range of integers.
It's public API consists of:
- bpf_iter_num_new() constructor, which accepts [start, end) range
(that is, start is inclusive, end is exclusive).
- bpf_iter_num_next() which will keep returning read-only pointer to int
until the range is exhausted, at which point NULL will be returned.
If bpf_iter_num_next() is kept calling after this, NULL will be
persistently returned.
- bpf_iter_num_destroy() destructor, which needs to be called at some
point to clean up iterator state. BPF verifier enforces that iterator
destructor is called at some point before BPF program exits.
Note that `start = end = X` is a valid combination to setup an empty
iterator. bpf_iter_num_new() will return 0 (success) for any such
combination.
If bpf_iter_num_new() detects invalid combination of input arguments, it
returns error, resets iterator state to, effectively, empty iterator, so
any subsequent call to bpf_iter_num_next() will keep returning NULL.
BPF verifier has no knowledge that returned integers are in the
[start, end) value range, as both `start` and `end` are not statically
known and enforced: they are runtime values.
While the implementation is pretty trivial, some care needs to be taken
to avoid overflows and underflows. Subsequent selftests will validate
correctness of [start, end) semantics, especially around extremes
(INT_MIN and INT_MAX).
Similarly to bpf_loop(), we enforce that no more than BPF_MAX_LOOPS can
be specified.
bpf_iter_num_{new,next,destroy}() is a logical evolution from bounded
BPF loops and bpf_loop() helper and is the basis for implementing
ergonomic BPF loops with no statically known or verified bounds.
Subsequent patches implement bpf_for() macro, demonstrating how this can
be wrapped into something that works and feels like a normal for() loop
in C language.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:16 +0000 (10:41 -0800)]
bpf: add support for open-coded iterator loops
Teach verifier about the concept of the open-coded (or inline) iterators.
This patch adds generic iterator loop verification logic, new STACK_ITER
stack slot type to contain iterator state, and necessary kfunc plumbing
for iterator's constructor, destructor and next methods. Next patch
implements first specific iterator (numbers iterator for implementing
for() loop logic). Such split allows to have more focused commits for
verifier logic and separate commit that we could point later to
demonstrating what does it take to add a new kind of iterator.
Each kind of iterator has its own associated struct bpf_iter_<type>,
where <type> denotes a specific type of iterator. struct bpf_iter_<type>
state is supposed to live on BPF program stack, so there will be no way
to change its size later on without breaking backwards compatibility, so
choose wisely! But given this struct is specific to a given <type> of
iterator, this allows a lot of flexibility: simple iterators could be
fine with just one stack slot (8 bytes), like numbers iterator in the
next patch, while some other more complicated iterators might need way
more to keep their iterator state. Either way, such design allows to
avoid runtime memory allocations, which otherwise would be necessary if
we fixed on-the-stack size and it turned out to be too small for a given
iterator implementation.
The way BPF verifier logic is implemented, there are no artificial
restrictions on a number of active iterators, it should work correctly
using multiple active iterators at the same time. This also means you
can have multiple nested iteration loops. struct bpf_iter_<type>
reference can be safely passed to subprograms as well.
General flow is easiest to demonstrate with a simple example using
number iterator implemented in next patch. Here's the simplest possible
loop:
struct bpf_iter_num it;
int *v;
bpf_iter_num_new(&it, 2, 5);
while ((v = bpf_iter_num_next(&it))) {
bpf_printk("X = %d", *v);
}
bpf_iter_num_destroy(&it);
Above snippet should output "X = 2", "X = 3", "X = 4". Note that 5 is
exclusive and is not returned. This matches similar APIs (e.g., slices
in Go or Rust) that implement a range of elements, where end index is
non-inclusive.
In the above example, we see a trio of function:
- constructor, bpf_iter_num_new(), which initializes iterator state
(struct bpf_iter_num it) on the stack. If any of the input arguments
are invalid, constructor should make sure to still initialize it such
that subsequent bpf_iter_num_next() calls will return NULL. I.e., on
error, return error and construct empty iterator.
- next method, bpf_iter_num_next(), which accepts pointer to iterator
state and produces an element. Next method should always return
a pointer. The contract between BPF verifier is that next method will
always eventually return NULL when elements are exhausted. Once NULL is
returned, subsequent next calls should keep returning NULL. In the
case of numbers iterator, bpf_iter_num_next() returns a pointer to an int
(storage for this integer is inside the iterator state itself),
which can be dereferenced after corresponding NULL check.
- once done with the iterator, it's mandated that user cleans up its
state with the call to destructor, bpf_iter_num_destroy() in this
case. Destructor frees up any resources and marks stack space used by
struct bpf_iter_num as usable for something else.
Any other iterator implementation will have to implement at least these
three methods. It is enforced that for any given type of iterator only
applicable constructor/destructor/next are callable. I.e., verifier
ensures you can't pass number iterator state into, say, cgroup
iterator's next method.
It is important to keep the naming pattern consistent to be able to
create generic macros to help with BPF iter usability. E.g., one
of the follow up patches adds generic bpf_for_each() macro to bpf_misc.h
in selftests, which allows to utilize iterator "trio" nicely without
having to code the above somewhat tedious loop explicitly every time.
This is enforced at kfunc registration point by one of the previous
patches in this series.
At the implementation level, iterator state tracking for verification
purposes is very similar to dynptr. We add STACK_ITER stack slot type,
reserve necessary number of slots, depending on
sizeof(struct bpf_iter_<type>), and keep track of necessary extra state
in the "main" slot, which is marked with non-zero ref_obj_id. Other
slots are also marked as STACK_ITER, but have zero ref_obj_id. This is
simpler than having a separate "is_first_slot" flag.
Another big distinction is that STACK_ITER is *always refcounted*, which
simplifies implementation without sacrificing usability. So no need for
extra "iter_id", no need to anticipate reuse of STACK_ITER slots for new
constructors, etc. Keeping it simple here.
As far as the verification logic goes, there are two extensive comments:
in process_iter_next_call() and iter_active_depths_differ() explaining
some important and sometimes subtle aspects. Please refer to them for
details.
But from 10,000-foot point of view, next methods are the points of
forking a verification state, which are conceptually similar to what
verifier is doing when validating conditional jump. We branch out at
a `call bpf_iter_<type>_next` instruction and simulate two outcomes:
NULL (iteration is done) and non-NULL (new element is returned). NULL is
simulated first and is supposed to reach exit without looping. After
that non-NULL case is validated and it either reaches exit (for trivial
examples with no real loop), or reaches another `call bpf_iter_<type>_next`
instruction with the state equivalent to already (partially) validated
one. State equivalency at that point means we technically are going to
be looping forever without "breaking out" out of established "state
envelope" (i.e., subsequent iterations don't add any new knowledge or
constraints to the verifier state, so running 1, 2, 10, or a million of
them doesn't matter). But taking into account the contract stating that
iterator next method *has to* return NULL eventually, we can conclude
that loop body is safe and will eventually terminate. Given we validated
logic outside of the loop (NULL case), and concluded that loop body is
safe (though potentially looping many times), verifier can claim safety
of the overall program logic.
The rest of the patch is necessary plumbing for state tracking, marking,
validation, and necessary further kfunc plumbing to allow implementing
iterator constructor, destructor, and next methods.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:15 +0000 (10:41 -0800)]
bpf: add iterator kfuncs registration and validation logic
Add ability to register kfuncs that implement BPF open-coded iterator
contract and enforce naming and function proto convention. Enforcement
happens at the time of kfunc registration and significantly simplifies
the rest of iterators logic in the verifier.
More details follow in subsequent patches, but we enforce the following
conditions.
All kfuncs (constructor, next, destructor) have to be named consistenly
as bpf_iter_<type>_{new,next,destroy}(), respectively. <type> represents
iterator type, and iterator state should be represented as a matching
`struct bpf_iter_<type>` state type. Also, all iter kfuncs should have
a pointer to this `struct bpf_iter_<type>` as the very first argument.
Additionally:
- Constructor, i.e., bpf_iter_<type>_new(), can have arbitrary extra
number of arguments. Return type is not enforced either.
- Next method, i.e., bpf_iter_<type>_next(), has to return a pointer
type and should have exactly one argument: `struct bpf_iter_<type> *`
(const/volatile/restrict and typedefs are ignored).
- Destructor, i.e., bpf_iter_<type>_destroy(), should return void and
should have exactly one argument, similar to the next method.
- struct bpf_iter_<type> size is enforced to be positive and
a multiple of 8 bytes (to fit stack slots correctly).
Such strictness and consistency allows to build generic helpers
abstracting important, but boilerplate, details to be able to use
open-coded iterators effectively and ergonomically (see bpf_for_each()
in subsequent patches). It also simplifies the verifier logic in some
places. At the same time, this doesn't hurt generality of possible
iterator implementations. Win-win.
Constructor kfunc is marked with a new KF_ITER_NEW flags, next method is
marked with KF_ITER_NEXT (and should also have KF_RET_NULL, of course),
while destructor kfunc is marked as KF_ITER_DESTROY.
Additionally, we add a trivial kfunc name validation: it should be
a valid non-NULL and non-empty string.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Wed, 8 Mar 2023 18:41:14 +0000 (10:41 -0800)]
bpf: factor out fetching basic kfunc metadata
Factor out logic to fetch basic kfunc metadata based on struct bpf_insn.
This is not exactly short or trivial code to just copy/paste and this
information is sometimes necessary in other parts of the verifier logic.
Subsequent patches will rely on this to determine if an instruction is
a kfunc call to iterator next method.
No functional changes intended, including that verbose() warning
behavior when kfunc is not allowed for a particular program type.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230308184121.1165081-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Jakub Kicinski [Wed, 8 Mar 2023 22:34:22 +0000 (14:34 -0800)]
Merge https://git./linux/kernel/git/bpf/bpf-next
Andrii Nakryiko says:
====================
pull-request: bpf-next 2023-03-08
We've added 23 non-merge commits during the last 2 day(s) which contain
a total of 28 files changed, 414 insertions(+), 104 deletions(-).
The main changes are:
1) Add more precise memory usage reporting for all BPF map types,
from Yafang Shao.
2) Add ARM32 USDT support to libbpf, from Puranjay Mohan.
3) Fix BTF_ID_LIST size causing problems in !CONFIG_DEBUG_INFO_BTF,
from Nathan Chancellor.
4) IMA selftests fix, from Roberto Sassu.
5) libbpf fix in APK support code, from Daniel Müller.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (23 commits)
selftests/bpf: Fix IMA test
libbpf: USDT arm arg parsing support
libbpf: Refactor parse_usdt_arg() to re-use code
libbpf: Fix theoretical u32 underflow in find_cd() function
bpf: enforce all maps having memory usage callback
bpf: offload map memory usage
bpf, net: xskmap memory usage
bpf, net: sock_map memory usage
bpf, net: bpf_local_storage memory usage
bpf: local_storage memory usage
bpf: bpf_struct_ops memory usage
bpf: queue_stack_maps memory usage
bpf: devmap memory usage
bpf: cpumap memory usage
bpf: bloom_filter memory usage
bpf: ringbuf memory usage
bpf: reuseport_array memory usage
bpf: stackmap memory usage
bpf: arraymap memory usage
bpf: hashtab memory usage
...
====================
Link: https://lore.kernel.org/r/20230308193533.1671597-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Roberto Sassu [Wed, 8 Mar 2023 10:37:13 +0000 (11:37 +0100)]
selftests/bpf: Fix IMA test
Commit
62622dab0a28 ("ima: return IMA digest value only when IMA_COLLECTED
flag is set") caused bpf_ima_inode_hash() to refuse to give non-fresh
digests. IMA test #3 assumed the old behavior, that bpf_ima_inode_hash()
still returned also non-fresh digests.
Correct the test by accepting both cases. If the samples returned are 1,
assume that the commit above is applied and that the returned digest is
fresh. If the samples returned are 2, assume that the commit above is not
applied, and check both the non-fresh and fresh digest.
Fixes:
62622dab0a28 ("ima: return IMA digest value only when IMA_COLLECTED flag is set")
Reported-by: David Vernet <void@manifault.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Matt Bobrowski <mattbobrowski@google.com>
Link: https://lore.kernel.org/bpf/20230308103713.1681200-1-roberto.sassu@huaweicloud.com
Eric Dumazet [Tue, 7 Mar 2023 14:59:59 +0000 (14:59 +0000)]
net: reclaim skb->scm_io_uring bit
Commit
0091bfc81741 ("io_uring/af_unix: defer registered
files gc to io_uring release") added one bit to struct sk_buff.
This structure is critical for networking, and we try very hard
to not add bloat on it, unless absolutely required.
For instance, we can use a specific destructor as a wrapper
around unix_destruct_scm(), to identify skbs that unix_gc()
has to special case.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Wed, 8 Mar 2023 13:19:44 +0000 (13:19 +0000)]
Merge branch 'sparx5-tc-flower-templates'
Steen Hegelund says:
====================
Add support for TC flower templates in Sparx5
This adds support for the TC template mechanism in the Sparx5 flower filter
implementation.
Templates are as such handled by the TC framework, but when a template is
created (using a chain id) there are by definition no filters on this
chain (an error will be returned if there are any).
If the templates chain id is one that is represented by a VCAP lookup, then
when the template is created, we know that it is safe to use the keys
provided in the template to change the keyset configuration for the (port,
lookup) combination, if this is needed to improve the match on the
template.
The original port keyset configuration is captured in the template state
information which is kept per port, so that when the template is deleted
the port keyset configuration can be restored to its previous setting.
The template also provides the protocol parameter which is the basic
information that is used to find out which port keyset configuration needs
to be changed.
The VCAPs and lookups are slightly different when it comes to which keys,
keysets and protocol are supported and used for selection, so in some
cases a bit of tweaking is needed to find a useful match. This is done by
e.g. removing a key that prevents the best matching keyset from being
selected.
The debugfs output that is provided for a port allows inspection of the
currently used keyset in each of the VCAPs lookups. So when a template has
been created the debugfs output allows you to verify if the keyset
configuration has been changed successfully.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Steen Hegelund [Tue, 7 Mar 2023 13:41:03 +0000 (14:41 +0100)]
net: microchip: sparx5: Add TC template support
This adds support for using the "template add" and "template destroy"
functionality to change the port keyset configuration.
If the VCAP lookup already contains rules, the port keyset is left
unchanged, as a change would make these rules unusable.
When the template is destroyed the port keyset configuration is restored.
The filters using the template chain will automatically be deleted by the
TC framework.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steen Hegelund [Tue, 7 Mar 2023 13:41:02 +0000 (14:41 +0100)]
net: microchip: sparx5: Add port keyset changing functionality
With this its is now possible for clients (like TC) to change the port
keyset configuration in the Sparx5 VCAPs.
This is typically done per traffic class which is guided with the L3
protocol information.
Before the change the current keyset configuration is collected in a list
that is handed back to the client.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steen Hegelund [Tue, 7 Mar 2023 13:41:01 +0000 (14:41 +0100)]
net: microchip: sparx5: Add TC template list to a port
This adds a list that is used to collect the templates that are active on a
port.
This allows the template creation to change the port configuration
and the template destruction to change it back.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steen Hegelund [Tue, 7 Mar 2023 13:41:00 +0000 (14:41 +0100)]
net: microchip: sparx5: Provide rule count, key removal and keyset select
This provides these 3 functions in the VCAP API:
- Count the number of rules in a VCAP lookup (chain)
- Remove a key from a VCAP rule
- Find the keyset that gives the smallest rule list from a list of keysets
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Steen Hegelund [Tue, 7 Mar 2023 13:40:59 +0000 (14:40 +0100)]
net: microchip: sparx5: Correct the spelling of the keysets in debugfs
Correct the name used in the debugfs output.
Signed-off-by: Steen Hegelund <steen.hegelund@microchip.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Arınç ÜNAL [Tue, 7 Mar 2023 09:56:19 +0000 (12:56 +0300)]
dt-bindings: net: dsa: mediatek,mt7530: change some descriptions to literal
The line endings must be preserved on gpio-controller, io-supply, and
reset-gpios properties to look proper when the YAML file is parsed.
Currently it's interpreted as a single line when parsed. Change the style
of the description of these properties to literal style to preserve the
line endings.
Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jiapeng Chong [Tue, 7 Mar 2023 05:41:38 +0000 (13:41 +0800)]
emulex/benet: clean up some inconsistent indenting
No functional modification involved.
drivers/net/ethernet/emulex/benet/be_cmds.c:1120 be_cmd_pmac_add() warn: inconsistent indenting.
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4396
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gustavo A. R. Silva [Mon, 6 Mar 2023 23:51:52 +0000 (17:51 -0600)]
net/mlx4_en: Replace fake flex-array with flexible-array member
Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.
Transform zero-length array into flexible-array member in struct
mlx4_en_rx_desc.
Address the following warnings found with GCC-13 and
-fstrict-flex-arrays=3 enabled:
drivers/net/ethernet/mellanox/mlx4/en_rx.c:88:30: warning: array subscript i is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
drivers/net/ethernet/mellanox/mlx4/en_rx.c:149:30: warning: array subscript 0 is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
drivers/net/ethernet/mellanox/mlx4/en_rx.c:127:30: warning: array subscript i is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
drivers/net/ethernet/mellanox/mlx4/en_rx.c:128:30: warning: array subscript i is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
drivers/net/ethernet/mellanox/mlx4/en_rx.c:129:30: warning: array subscript i is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
drivers/net/ethernet/mellanox/mlx4/en_rx.c:117:30: warning: array subscript i is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
drivers/net/ethernet/mellanox/mlx4/en_rx.c:119:30: warning: array subscript i is outside array bounds of ‘struct mlx4_wqe_data_seg[0]’ [-Warray-bounds=]
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/264
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Tariq Toukan <tariqt@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David S. Miller [Wed, 8 Mar 2023 09:31:31 +0000 (09:31 +0000)]
Merge branch 'r8169-disable-ASPM-during-NAPI-poll'
Heiner Kallweit says:
====================
r8169: disable ASPM during NAPI poll
This is a rework of ideas from Kai-Heng on how to avoid the known
ASPM issues whilst still allowing for a maximum of ASPM-related power
savings. As a prerequisite some locking is added first.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiner Kallweit [Mon, 6 Mar 2023 21:28:06 +0000 (22:28 +0100)]
r8169: remove ASPM restrictions now that ASPM is disabled during NAPI poll
Now that ASPM is disabled during NAPI poll, we can remove all ASPM
restrictions. This allows for higher power savings if the network
isn't fully loaded.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiner Kallweit [Mon, 6 Mar 2023 21:26:47 +0000 (22:26 +0100)]
r8169: disable ASPM during NAPI poll
Several chip versions have problems with ASPM, what may result in
rx_missed errors or tx timeouts. The root cause isn't known but
experience shows that disabling ASPM during NAPI poll can avoid
these problems.
Suggested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiner Kallweit [Mon, 6 Mar 2023 21:25:49 +0000 (22:25 +0100)]
r8169: prepare rtl_hw_aspm_clkreq_enable for usage in atomic context
Bail out if the function is used with chip versions that don't support
ASPM configuration. In addition remove the delay, it tuned out that
it's not needed, also vendor driver r8125 doesn't have it.
Suggested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiner Kallweit [Mon, 6 Mar 2023 21:24:49 +0000 (22:24 +0100)]
r8169: enable cfg9346 config register access in atomic context
For disabling ASPM during NAPI poll we'll have to unlock access
to the config registers in atomic context. Other code parts
running with config register access unlocked are partially
longer and can sleep. Add a usage counter to enable parallel
execution of code parts requiring unlocked config registers.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiner Kallweit [Mon, 6 Mar 2023 21:24:00 +0000 (22:24 +0100)]
r8169: use spinlock to protect access to registers Config2 and Config5
For disabling ASPM during NAPI poll we'll have to access both registers
in atomic context. Use a spinlock to protect access.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Heiner Kallweit [Mon, 6 Mar 2023 21:23:15 +0000 (22:23 +0100)]
r8169: use spinlock to protect mac ocp register access
For disabling ASPM during NAPI poll we'll have to access mac ocp
registers in atomic context. This could result in races because
a mac ocp read consists of a write to register OCPDR, followed
by a read from the same register. Therefore add a spinlock to
protect access to mac ocp registers.
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Vadim Fedorenko [Mon, 6 Mar 2023 16:07:38 +0000 (08:07 -0800)]
net-timestamp: extend SOF_TIMESTAMPING_OPT_ID to HW timestamps
When the feature was added it was enabled for SW timestamps only but
with current hardware the same out-of-order timestamps can be seen.
Let's expand the area for the feature to all types of timestamps.
Signed-off-by: Vadim Fedorenko <vadfed@meta.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Gustavo A. R. Silva [Mon, 6 Mar 2023 23:40:28 +0000 (17:40 -0600)]
netxen_nic: Replace fake flex-array with flexible-array member
Zero-length arrays as fake flexible arrays are deprecated and we are
moving towards adopting C99 flexible-array members instead.
Transform zero-length array into flexible-array member in struct
nx_cardrsp_rx_ctx_t.
Address the following warnings found with GCC-13 and
-fstrict-flex-arrays=3 enabled:
drivers/net/ethernet/qlogic/netxen/netxen_nic_ctx.c:361:26: warning: array subscript <unknown> is outside array bounds of ‘char[0]’ [-Warray-bounds=]
drivers/net/ethernet/qlogic/netxen/netxen_nic_ctx.c:372:25: warning: array subscript <unknown> is outside array bounds of ‘char[0]’ [-Warray-bounds=]
This helps with the ongoing efforts to tighten the FORTIFY_SOURCE
routines on memcpy() and help us make progress towards globally
enabling -fstrict-flex-arrays=3 [1].
Link: https://github.com/KSPP/linux/issues/21
Link: https://github.com/KSPP/linux/issues/265
Link: https://gcc.gnu.org/pipermail/gcc-patches/2022-October/602902.html
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/ZAZ57I6WdQEwWh7v@work
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Heiner Kallweit [Mon, 6 Mar 2023 22:10:57 +0000 (23:10 +0100)]
net: phy: smsc: simplify lan95xx_config_aneg_ext
lan95xx_config_aneg_ext() can be simplified by using phy_set_bits().
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Link: https://lore.kernel.org/r/3da785c7-3ef8-b5d3-89a0-340f550be3c2@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Eric Dumazet [Mon, 6 Mar 2023 20:43:13 +0000 (20:43 +0000)]
net: remove enum skb_free_reason
enum skb_drop_reason is more generic, we can adopt it instead.
Provide dev_kfree_skb_irq_reason() and dev_kfree_skb_any_reason().
This means drivers can use more precise drop reasons if they want to.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Yunsheng Lin <linyunsheng@huawei.com>
Link: https://lore.kernel.org/r/20230306204313.10492-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Heiner Kallweit [Mon, 6 Mar 2023 21:51:35 +0000 (22:51 +0100)]
net: phy: improve phy_read_poll_timeout
cond sometimes is (val & MASK) what may result in a false positive
if val is a negative errno. We shouldn't evaluate cond if val < 0.
This has no functional impact here, but it's not nice.
Therefore switch order of the checks.
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/6d8274ac-4344-23b4-d9a3-cad4c39517d4@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Andrii Nakryiko [Tue, 7 Mar 2023 23:31:13 +0000 (15:31 -0800)]
Merge branch 'libbpf: usdt arm arg parsing support'
Puranjay Mohan says:
====================
This series add the support of the ARM architecture to libbpf USDT. This
involves implementing the parse_usdt_arg() function for ARM.
It was seen that the last part of parse_usdt_arg() is repeated for all architectures,
so, the first patch in this series refactors these functions and moved the post
processing to parse_usdt_spec()
Changes in V2[1] to V3:
- Use a tabular approach to find register offsets.
- Add the patch for refactoring parse_usdt_arg()
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Puranjay Mohan [Tue, 7 Mar 2023 12:04:40 +0000 (12:04 +0000)]
libbpf: USDT arm arg parsing support
Parsing of USDT arguments is architecture-specific; on arm it is
relatively easy since registers used are r[0-10], fp, ip, sp, lr,
pc. Format is slightly different compared to aarch64; forms are
- "size @ [ reg, #offset ]" for dereferences, for example
"-8 @ [ sp, #76 ]" ; " -4 @ [ sp ]"
- "size @ reg" for register values; for example
"-4@r0"
- "size @ #value" for raw values; for example
"-8@#1"
Add support for parsing USDT arguments for ARM architecture.
To test the above changes QEMU's virt[1] board with cortex-a15
CPU was used. libbpf-bootstrap's usdt example[2] was modified to attach
to a test program with DTRACE_PROBE1/2/3/4... probes to test different
combinations.
[1] https://www.qemu.org/docs/master/system/arm/virt.html
[2] https://github.com/libbpf/libbpf-bootstrap/blob/master/examples/c/usdt.bpf.c
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230307120440.25941-3-puranjay12@gmail.com
Puranjay Mohan [Tue, 7 Mar 2023 12:04:39 +0000 (12:04 +0000)]
libbpf: Refactor parse_usdt_arg() to re-use code
The parse_usdt_arg() function is defined differently for each
architecture but the last part of the function is repeated
verbatim for each architecture.
Refactor parse_usdt_arg() to fill the arg_sz and then do the repeated
post-processing in parse_usdt_spec().
Signed-off-by: Puranjay Mohan <puranjay12@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230307120440.25941-2-puranjay12@gmail.com
Daniel Müller [Tue, 7 Mar 2023 21:55:04 +0000 (21:55 +0000)]
libbpf: Fix theoretical u32 underflow in find_cd() function
Coverity reported a potential underflow of the offset variable used in
the find_cd() function. Switch to using a signed 64 bit integer for the
representation of offset to make sure we can never underflow.
Fixes:
1eebcb60633f ("libbpf: Implement basic zip archive parsing support")
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230307215504.837321-1-deso@posteo.net
Alexei Starovoitov [Tue, 7 Mar 2023 17:33:43 +0000 (09:33 -0800)]
Merge branch 'bpf: bpf memory usage'
Yafang Shao says:
====================
Currently we can't get bpf memory usage reliably either from memcg or
from bpftool.
In memcg, there's not a 'bpf' item in memory.stat, but only 'kernel',
'sock', 'vmalloc' and 'percpu' which may related to bpf memory. With
these items we still can't get the bpf memory usage, because bpf memory
usage may far less than the kmem in a memcg, for example, the dentry may
consume lots of kmem.
bpftool now shows the bpf memory footprint, which is difference with bpf
memory usage. The difference can be quite great in some cases, for example,
- non-preallocated bpf map
The non-preallocated bpf map memory usage is dynamically changed. The
allocated elements count can be from 0 to the max entries. But the
memory footprint in bpftool only shows a fixed number.
- bpf metadata consumes more memory than bpf element
In some corner cases, the bpf metadata can consumes a lot more memory
than bpf element consumes. For example, it can happen when the element
size is quite small.
- some maps don't have key, value or max_entries
For example the key_size and value_size of ringbuf is 0, so its
memlock is always 0.
We need a way to show the bpf memory usage especially there will be more
and more bpf programs running on the production environment and thus the
bpf memory usage is not trivial.
This patchset introduces a new map ops ->map_mem_usage to calculate the
memory usage. Note that we don't intend to make the memory usage 100%
accurate, while our goal is to make sure there is only a small difference
between what bpftool reports and the real memory. That small difference
can be ignored compared to the total usage. That is enough to monitor
the bpf memory usage. For example, the user can rely on this value to
monitor the trend of bpf memory usage, compare the difference in bpf
memory usage between different bpf program versions, figure out which
maps consume large memory, and etc.
This patchset implements the bpf memory usage for all maps, and yet there's
still work to do. We don't want to introduce runtime overhead in the
element update and delete path, but we have to do it for some
non-preallocated maps,
- devmap, xskmap
When we update or delete an element, it will allocate or free memory.
In order to track this dynamic memory, we have to track the count in
element update and delete path.
- cpumap
The element size of each cpumap element is not determinated. If we
want to track the usage, we have to count the size of all elements in
the element update and delete path. So I just put it aside currently.
- local_storage, bpf_local_storage
When we attach or detach a cgroup, it will allocate or free memory. If
we want to track the dynamic memory, we also need to do something in
the update and delete path. So I just put it aside currently.
- offload map
The element update and delete of offload map is via the netdev dev_ops,
in which it may dynamically allocate or free memory, but this dynamic
memory isn't counted in offload map memory usage currently.
The result of each map can be found in the individual patch.
We may also need to track per-container bpf memory usage, that will be
addressed by a different patchset.
Changes:
v3->v4: code improvement on ringbuf (Andrii)
use READ_ONCE() to read lpm_trie (Tao)
explain why we can't get bpf memory usage from memcg.
v2->v3: check callback at map creation time and avoid warning (Alexei)
fix build error under CONFIG_BPF=n (lkp@intel.com)
v1->v2: calculate the memory usage within bpf (Alexei)
- [v1] bpf, mm: bpf memory usage
https://lwn.net/Articles/921991/
- [RFC PATCH v2] mm, bpf: Add BPF into /proc/meminfo
https://lwn.net/Articles/919848/
- [RFC PATCH v1] mm, bpf: Add BPF into /proc/meminfo
https://lwn.net/Articles/917647/
- [RFC PATCH] bpf, mm: Add a new item bpf into memory.stat
https://lore.kernel.org/bpf/
20220921170002.29557-1-laoar.shao@gmail].com/
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:15 +0000 (12:46 +0000)]
bpf: enforce all maps having memory usage callback
We have implemented memory usage callback for all maps, and we enforce
any newly added map having a callback as well. We check this callback at
map creation time. If it doesn't have the callback, we will return
EINVAL.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-19-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:14 +0000 (12:46 +0000)]
bpf: offload map memory usage
A new helper is introduced to calculate offload map memory usage. But
currently the memory dynamically allocated in netdev dev_ops, like
nsim_map_update_elem, is not counted. Let's just put it aside now.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-18-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:13 +0000 (12:46 +0000)]
bpf, net: xskmap memory usage
A new helper is introduced to calculate xskmap memory usage.
The xfsmap memory usage can be dynamically changed when we add or remove
a xsk_map_node. Hence we need to track the count of xsk_map_node to get
its memory usage.
The result as follows,
- before
10: xskmap name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
- after
10: xskmap name count_map flags 0x0 <<< no elements case
key 4B value 4B max_entries 65536 memlock
524608B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-17-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:12 +0000 (12:46 +0000)]
bpf, net: sock_map memory usage
sockmap and sockhash don't have something in common in allocation, so let's
introduce different helpers to calculate their memory usage.
The reuslt as follows,
- before
28: sockmap name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
29: sockhash name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
- after
28: sockmap name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524608B
29: sockhash name count_map flags 0x0 <<<< no updated elements
key 4B value 4B max_entries 65536 memlock
1048896B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-16-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:11 +0000 (12:46 +0000)]
bpf, net: bpf_local_storage memory usage
A new helper is introduced into bpf_local_storage map to calculate the
memory usage. This helper is also used by other maps like
bpf_cgrp_storage, bpf_inode_storage, bpf_task_storage and etc.
Note that currently the dynamically allocated storage elements are not
counted in the usage, since it will take extra runtime overhead in the
elements update or delete path. So let's put it aside now, and implement
it in the future when someone really need it.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-15-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:10 +0000 (12:46 +0000)]
bpf: local_storage memory usage
A new helper is introduced to calculate local_storage map memory usage.
Currently the dynamically allocated elements are not counted, since it
will take runtime overhead in the element update or delete path. So
let's put it aside currently, and implement it in the future if the user
really needs it.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-14-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:09 +0000 (12:46 +0000)]
bpf: bpf_struct_ops memory usage
A new helper is introduced to calculate bpf_struct_ops memory usage.
The result as follows,
- before
1: struct_ops name count_map flags 0x0
key 4B value 256B max_entries 1 memlock 4096B
btf_id 73
- after
1: struct_ops name count_map flags 0x0
key 4B value 256B max_entries 1 memlock 5016B
btf_id 73
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-13-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:08 +0000 (12:46 +0000)]
bpf: queue_stack_maps memory usage
A new helper is introduced to calculate queue_stack_maps memory usage.
The result as follows,
- before
20: queue name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock
266240B
21: stack name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock
266240B
- after
20: queue name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock
524288B
21: stack name count_map flags 0x0
key 0B value 4B max_entries 65536 memlock
524288B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-12-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:07 +0000 (12:46 +0000)]
bpf: devmap memory usage
A new helper is introduced to calculate the memory usage of devmap and
devmap_hash. The number of dynamically allocated elements are recored
for devmap_hash already, but not for devmap. To track the memory size of
dynamically allocated elements, this patch also count the numbers for
devmap.
The result as follows,
- before
40: devmap name count_map flags 0x80
key 4B value 4B max_entries 65536 memlock
524288B
41: devmap_hash name count_map flags 0x80
key 4B value 4B max_entries 65536 memlock
524288B
- after
40: devmap name count_map flags 0x80 <<<< no elements
key 4B value 4B max_entries 65536 memlock
524608B
41: devmap_hash name count_map flags 0x80 <<<< no elements
key 4B value 4B max_entries 65536 memlock
524608B
Note that the number of buckets is same with max_entries for devmap_hash
in this case.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-11-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:06 +0000 (12:46 +0000)]
bpf: cpumap memory usage
A new helper is introduced to calculate cpumap memory usage. The size of
cpu_entries can be dynamically changed when we update or delete a cpumap
element, but this patch doesn't include the memory size of cpu_entry
yet. We can dynamically calculate the memory usage when we alloc or free
a cpu_entry, but it will take extra runtime overhead, so let just put it
aside currently. Note that the size of different cpu_entry may be
different as well.
The result as follows,
- before
48: cpumap name count_map flags 0x4
key 4B value 4B max_entries 64 memlock 4096B
- after
48: cpumap name count_map flags 0x4
key 4B value 4B max_entries 64 memlock 832B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-10-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:05 +0000 (12:46 +0000)]
bpf: bloom_filter memory usage
Introduce a new helper to calculate the bloom_filter memory usage.
The result as follows,
- before
16: bloom_filter flags 0x0
key 0B value 8B max_entries 65536 memlock
524288B
- after
16: bloom_filter flags 0x0
key 0B value 8B max_entries 65536 memlock 65856B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-9-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:04 +0000 (12:46 +0000)]
bpf: ringbuf memory usage
A new helper ringbuf_map_mem_usage() is introduced to calculate ringbuf
memory usage.
The result as follows,
- before
15: ringbuf name count_map flags 0x0
key 0B value 0B max_entries 65536 memlock 0B
- after
15: ringbuf name count_map flags 0x0
key 0B value 0B max_entries 65536 memlock 78424B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230305124615.12358-8-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:03 +0000 (12:46 +0000)]
bpf: reuseport_array memory usage
A new helper is introduced to calculate reuseport_array memory usage.
The result as follows,
- before
14: reuseport_sockarray name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock
1048576B
- after
14: reuseport_sockarray name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock
524544B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-7-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:02 +0000 (12:46 +0000)]
bpf: stackmap memory usage
A new helper is introduced to get stackmap memory usage. Some small
memory allocations are ignored as their memory size is quite small
compared to the totol usage.
The result as follows,
- before
16: stack_trace name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock
1048576B
- after
16: stack_trace name count_map flags 0x0
key 4B value 8B max_entries 65536 memlock
2097472B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-6-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:01 +0000 (12:46 +0000)]
bpf: arraymap memory usage
Introduce array_map_mem_usage() to calculate arraymap memory usage. In
this helper, some small memory allocations are ignored, like the
allocation of struct bpf_array_aux in prog_array. The inner_map_meta in
array_of_map is also ignored.
The result as follows,
- before
11: array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
12: percpu_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
8912896B
13: perf_event_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
14: prog_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
15: cgroup_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524288B
- after
11: array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524608B
12: percpu_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
17301824B
13: perf_event_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524608B
14: prog_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524608B
15: cgroup_array name count_map flags 0x0
key 4B value 4B max_entries 65536 memlock
524608B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-5-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:46:00 +0000 (12:46 +0000)]
bpf: hashtab memory usage
htab_map_mem_usage() is introduced to calculate hashmap memory usage. In
this helper, some small memory allocations are ignore, as their size is
quite small compared with the total size. The inner_map_meta in
hash_of_map is also ignored.
The result for hashtab as follows,
- before this change
1: hash name count_map flags 0x1 <<<< no prealloc, fully set
key 16B value 24B max_entries
1048576 memlock
41943040B
2: hash name count_map flags 0x1 <<<< no prealloc, none set
key 16B value 24B max_entries
1048576 memlock
41943040B
3: hash name count_map flags 0x0 <<<< prealloc
key 16B value 24B max_entries
1048576 memlock
41943040B
The memlock is always a fixed size whatever it is preallocated or
not, and whatever the count of allocated elements is.
- after this change
1: hash name count_map flags 0x1 <<<< non prealloc, fully set
key 16B value 24B max_entries
1048576 memlock
117441536B
2: hash name count_map flags 0x1 <<<< non prealloc, non set
key 16B value 24B max_entries
1048576 memlock
16778240B
3: hash name count_map flags 0x0 <<<< prealloc
key 16B value 24B max_entries
1048576 memlock
109056000B
The memlock now is hashtab actually allocated.
The result for percpu hash map as follows,
- before this change
4: percpu_hash name count_map flags 0x0 <<<< prealloc
key 16B value 24B max_entries
1048576 memlock
822083584B
5: percpu_hash name count_map flags 0x1 <<<< no prealloc
key 16B value 24B max_entries
1048576 memlock
822083584B
- after this change
4: percpu_hash name count_map flags 0x0
key 16B value 24B max_entries
1048576 memlock
897582080B
5: percpu_hash name count_map flags 0x1
key 16B value 24B max_entries
1048576 memlock
922748736B
At worst, the difference can be 10x, for example,
- before this change
6: hash name count_map flags 0x0
key 4B value 4B max_entries
1048576 memlock
8388608B
- after this change
6: hash name count_map flags 0x0
key 4B value 4B max_entries
1048576 memlock
83889408B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230305124615.12358-4-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:45:59 +0000 (12:45 +0000)]
bpf: lpm_trie memory usage
trie_mem_usage() is introduced to calculate the lpm_trie memory usage.
Some small memory allocations are ignored. The inner node is also
ignored.
The result as follows,
- before
10: lpm_trie flags 0x1
key 8B value 8B max_entries 65536 memlock
1048576B
- after
10: lpm_trie flags 0x1
key 8B value 8B max_entries 65536 memlock
2291536B
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-3-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Yafang Shao [Sun, 5 Mar 2023 12:45:58 +0000 (12:45 +0000)]
bpf: add new map ops ->map_mem_usage
Add a new map ops ->map_mem_usage to print the memory usage of a
bpf map.
This is a preparation for the followup change.
Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
Link: https://lore.kernel.org/r/20230305124615.12358-2-laoar.shao@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Nathan Chancellor [Tue, 7 Mar 2023 15:14:06 +0000 (08:14 -0700)]
bpf: Increase size of BTF_ID_LIST without CONFIG_DEBUG_INFO_BTF again
After commit
66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr"),
clang builds without CONFIG_DEBUG_INFO_BTF warn:
kernel/bpf/verifier.c:10298:24: warning: array index 16 is past the end of the array (that has type 'u32[16]' (aka 'unsigned int[16]')) [-Warray-bounds]
meta.func_id == special_kfunc_list[KF_bpf_dynptr_slice_rdwr]) {
^ ~~~~~~~~~~~~~~~~~~~~~~~~
kernel/bpf/verifier.c:9150:1: note: array 'special_kfunc_list' declared here
BTF_ID_LIST(special_kfunc_list)
^
include/linux/btf_ids.h:207:27: note: expanded from macro 'BTF_ID_LIST'
#define BTF_ID_LIST(name) static u32 __maybe_unused name[16];
^
1 warning generated.
A warning of this nature was previously addressed by
commit
beb3d47d1d3d ("bpf: Fix a BTF_ID_LIST bug with CONFIG_DEBUG_INFO_BTF not set")
but there have been new kfuncs added since then.
Quadruple the size of the CONFIG_DEBUG_INFO_BTF=n definition so that
this problem is unlikely to show up for some time.
Link: https://github.com/ClangBuiltLinux/linux/issues/1810
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Tom Rix <trix@redhat.com>
Link: https://lore.kernel.org/r/20230307-bpf-kfuncs-warray-bounds-v1-1-00ad3191f3a6@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Jakub Kicinski [Tue, 7 Mar 2023 04:36:39 +0000 (20:36 -0800)]
Merge tag 'for-netdev' of https://git./linux/kernel/git/bpf/bpf-next
Daniel Borkmann says:
====================
pull-request: bpf-next 2023-03-06
We've added 85 non-merge commits during the last 13 day(s) which contain
a total of 131 files changed, 7102 insertions(+), 1792 deletions(-).
The main changes are:
1) Add skb and XDP typed dynptrs which allow BPF programs for more
ergonomic and less brittle iteration through data and variable-sized
accesses, from Joanne Koong.
2) Bigger batch of BPF verifier improvements to prepare for upcoming BPF
open-coded iterators allowing for less restrictive looping capabilities,
from Andrii Nakryiko.
3) Rework RCU enforcement in the verifier, add kptr_rcu and enforce BPF
programs to NULL-check before passing such pointers into kfunc,
from Alexei Starovoitov.
4) Add support for kptrs in percpu hashmaps, percpu LRU hashmaps and in
local storage maps, from Kumar Kartikeya Dwivedi.
5) Add BPF verifier support for ST instructions in convert_ctx_access()
which will help new -mcpu=v4 clang flag to start emitting them,
from Eduard Zingerman.
6) Make uprobe attachment Android APK aware by supporting attachment
to functions inside ELF objects contained in APKs via function names,
from Daniel Müller.
7) Add a new flag BPF_F_TIMER_ABS flag for bpf_timer_start() helper
to start the timer with absolute expiration value instead of relative
one, from Tero Kristo.
8) Add a new kfunc bpf_cgroup_from_id() to look up cgroups via id,
from Tejun Heo.
9) Extend libbpf to support users manually attaching kprobes/uprobes
in the legacy/perf/link mode, from Menglong Dong.
10) Implement workarounds in the mips BPF JIT for DADDI/R4000,
from Jiaxun Yang.
11) Enable mixing bpf2bpf and tailcalls for the loongarch BPF JIT,
from Hengqi Chen.
12) Extend BPF instruction set doc with describing the encoding of BPF
instructions in terms of how bytes are stored under big/little endian,
from Jose E. Marchesi.
13) Follow-up to enable kfunc support for riscv BPF JIT, from Pu Lehui.
14) Fix bpf_xdp_query() backwards compatibility on old kernels,
from Yonghong Song.
15) Fix BPF selftest cross compilation with CLANG_CROSS_FLAGS,
from Florent Revest.
16) Improve bpf_cpumask_ma to only allocate one bpf_mem_cache,
from Hou Tao.
17) Fix BPF verifier's check_subprogs to not unnecessarily mark
a subprogram with has_tail_call, from Ilya Leoshkevich.
18) Fix arm syscall regs spec in libbpf's bpf_tracing.h, from Puranjay Mohan.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (85 commits)
selftests/bpf: Add test for legacy/perf kprobe/uprobe attach mode
selftests/bpf: Split test_attach_probe into multi subtests
libbpf: Add support to set kprobe/uprobe attach mode
tools/resolve_btfids: Add /libsubcmd to .gitignore
bpf: add support for fixed-size memory pointer returns for kfuncs
bpf: generalize dynptr_get_spi to be usable for iters
bpf: mark PTR_TO_MEM as non-null register type
bpf: move kfunc_call_arg_meta higher in the file
bpf: ensure that r0 is marked scratched after any function call
bpf: fix visit_insn()'s detection of BPF_FUNC_timer_set_callback helper
bpf: clean up visit_insn()'s instruction processing
selftests/bpf: adjust log_fixup's buffer size for proper truncation
bpf: honor env->test_state_freq flag in is_state_visited()
selftests/bpf: enhance align selftest's expected log matching
bpf: improve regsafe() checks for PTR_TO_{MEM,BUF,TP_BUFFER}
bpf: improve stack slot state printing
selftests/bpf: Disassembler tests for verifier.c:convert_ctx_access()
selftests/bpf: test if pointer type is tracked for BPF_ST_MEM
bpf: allow ctx writes using BPF_ST_MEM instruction
bpf: Use separate RCU callbacks for freeing selem
...
====================
Link: https://lore.kernel.org/r/20230307004346.27578-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Andrii Nakryiko [Mon, 6 Mar 2023 17:30:21 +0000 (09:30 -0800)]
Merge branch 'libbpf: allow users to set kprobe/uprobe attach mode'
Menglong Dong says:
====================
From: Menglong Dong <imagedong@tencent.com>
By default, libbpf will attach the kprobe/uprobe BPF program in the
latest mode that supported by kernel. In this series, we add the support
to let users manually attach kprobe/uprobe in legacy/perf/link mode in
the 1th patch.
And in the 2th patch, we split the testing 'attach_probe' into multi
subtests, as Andrii suggested.
In the 3th patch, we add the testings for loading kprobe/uprobe in
different mode.
Changes since v3:
- rename eBPF to BPF in the doc
- use OPTS_GET() to get the value of 'force_ioctl_attach'
- error out on attach mode is not supported
- use test_attach_probe_manual__open_and_load() directly
Changes since v2:
- fix the typo in the 2th patch
Changes since v1:
- some small changes in the 1th patch, as Andrii suggested
- split 'attach_probe' into multi subtests
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Menglong Dong [Mon, 6 Mar 2023 06:48:33 +0000 (14:48 +0800)]
selftests/bpf: Add test for legacy/perf kprobe/uprobe attach mode
Add the testing for kprobe/uprobe attaching in default, legacy, perf and
link mode. And the testing passed:
./test_progs -t attach_probe
$5/1 attach_probe/manual-default:OK
$5/2 attach_probe/manual-legacy:OK
$5/3 attach_probe/manual-perf:OK
$5/4 attach_probe/manual-link:OK
$5/5 attach_probe/auto:OK
$5/6 attach_probe/kprobe-sleepable:OK
$5/7 attach_probe/uprobe-lib:OK
$5/8 attach_probe/uprobe-sleepable:OK
$5/9 attach_probe/uprobe-ref_ctr:OK
$5 attach_probe:OK
Summary: 1/9 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Biao Jiang <benbjiang@tencent.com>
Link: https://lore.kernel.org/bpf/20230306064833.7932-4-imagedong@tencent.com
Menglong Dong [Mon, 6 Mar 2023 06:48:32 +0000 (14:48 +0800)]
selftests/bpf: Split test_attach_probe into multi subtests
In order to adapt to the older kernel, now we split the "attach_probe"
testing into multi subtests:
manual // manual attach tests for kprobe/uprobe
auto // auto-attach tests for kprobe and uprobe
kprobe-sleepable // kprobe sleepable test
uprobe-lib // uprobe tests for library function by name
uprobe-sleepable // uprobe sleepable test
uprobe-ref_ctr // uprobe ref_ctr test
As sleepable kprobe needs to set BPF_F_SLEEPABLE flag before loading,
we need to move it to a stand alone skel file, in case of it is not
supported by kernel and make the whole loading fail.
Therefore, we can only enable part of the subtests for older kernel.
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Biao Jiang <benbjiang@tencent.com>
Link: https://lore.kernel.org/bpf/20230306064833.7932-3-imagedong@tencent.com
Menglong Dong [Mon, 6 Mar 2023 06:48:31 +0000 (14:48 +0800)]
libbpf: Add support to set kprobe/uprobe attach mode
By default, libbpf will attach the kprobe/uprobe BPF program in the
latest mode that supported by kernel. In this patch, we add the support
to let users manually attach kprobe/uprobe in legacy or perf mode.
There are 3 mode that supported by the kernel to attach kprobe/uprobe:
LEGACY: create perf event in legacy way and don't use bpf_link
PERF: create perf event with perf_event_open() and don't use bpf_link
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Biao Jiang <benbjiang@tencent.com>
Link: create perf event with perf_event_open() and use bpf_link
Link: https://lore.kernel.org/bpf/20230113093427.1666466-1-imagedong@tencent.com/
Link: https://lore.kernel.org/bpf/20230306064833.7932-2-imagedong@tencent.com
Users now can manually choose the mode with
bpf_program__attach_uprobe_opts()/bpf_program__attach_kprobe_opts().
Rong Tao [Sat, 4 Mar 2023 15:17:04 +0000 (23:17 +0800)]
tools/resolve_btfids: Add /libsubcmd to .gitignore
Add libsubcmd to .gitignore, otherwise after compiling the kernel it
would result in the following:
# bpf-next...bpf-next/master
?? tools/bpf/resolve_btfids/libsubcmd/
Signed-off-by: Rong Tao <rongtao@cestc.cn>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/tencent_F13D670D5D7AA9C4BD868D3220921AAC090A@qq.com
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:10 +0000 (15:50 -0800)]
bpf: add support for fixed-size memory pointer returns for kfuncs
Support direct fixed-size (and for now, read-only) memory access when
kfunc's return type is a pointer to non-struct type. Calculate type size
and let BPF program access that many bytes directly. This is crucial for
numbers iterator.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-13-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:09 +0000 (15:50 -0800)]
bpf: generalize dynptr_get_spi to be usable for iters
Generalize the logic of fetching special stack slot object state using
spi (stack slot index). This will be used by STACK_ITER logic next.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-12-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:08 +0000 (15:50 -0800)]
bpf: mark PTR_TO_MEM as non-null register type
PTR_TO_MEM register without PTR_MAYBE_NULL is indeed non-null. This is
important for BPF verifier to be able to prune guaranteed not to be
taken branches. This is always the case with open-coded iterators.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-11-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:07 +0000 (15:50 -0800)]
bpf: move kfunc_call_arg_meta higher in the file
Move struct bpf_kfunc_call_arg_meta higher in the file and put it next
to struct bpf_call_arg_meta, so it can be used from more functions.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:06 +0000 (15:50 -0800)]
bpf: ensure that r0 is marked scratched after any function call
r0 is important (unless called function is void-returning, but that's
taken care of by print_verifier_state() anyways) in verifier logs.
Currently for helpers we seem to print it in verifier log, but for
kfuncs we don't.
Instead of figuring out where in the maze of code we accidentally set r0
as scratched for helpers and why we don't do that for kfuncs, just
enforce that after any function call r0 is marked as scratched.
Also, perhaps, we should reconsider "scratched" terminology, as it's
mightily confusing. "Touched" would seem more appropriate. But I left
that for follow ups for now.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-9-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:05 +0000 (15:50 -0800)]
bpf: fix visit_insn()'s detection of BPF_FUNC_timer_set_callback helper
It's not correct to assume that any BPF_CALL instruction is a helper
call. Fix visit_insn()'s detection of bpf_timer_set_callback() helper by
also checking insn->code == 0. For kfuncs insn->code would be set to
BPF_PSEUDO_KFUNC_CALL, and for subprog calls it will be BPF_PSEUDO_CALL.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:04 +0000 (15:50 -0800)]
bpf: clean up visit_insn()'s instruction processing
Instead of referencing processed instruction repeatedly as insns[t]
throughout entire visit_insn() function, take a local insn pointer and
work with it in a cleaner way.
It makes enhancing this function further a bit easier as well.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-7-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:03 +0000 (15:50 -0800)]
selftests/bpf: adjust log_fixup's buffer size for proper truncation
Adjust log_fixup's expected buffer length to fix the test. It's pretty
finicky in its length expectation, but it doesn't break often. So just
adjust the length to work on current kernel and with follow up iterator
changes as well.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:02 +0000 (15:50 -0800)]
bpf: honor env->test_state_freq flag in is_state_visited()
env->test_state_freq flag can be set by user by passing
BPF_F_TEST_STATE_FREQ program flag. This is used in a bunch of selftests
to have predictable state checkpoints at every jump and so on.
Currently, bounded loop handling heuristic ignores this flag if number
of processed jumps and/or number of processed instructions is below some
thresholds, which throws off that reliable state checkpointing.
Honor this flag in all circumstances by disabling heuristic if
env->test_state_freq is set.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-5-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:01 +0000 (15:50 -0800)]
selftests/bpf: enhance align selftest's expected log matching
Allow to search for expected register state in all the verifier log
output that's related to specified instruction number.
See added comment for an example of possible situation that is happening
due to a simple enhancement done in the next patch, which fixes handling
of env->test_state_freq flag in state checkpointing logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-4-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:50:00 +0000 (15:50 -0800)]
bpf: improve regsafe() checks for PTR_TO_{MEM,BUF,TP_BUFFER}
Teach regsafe() logic to handle PTR_TO_MEM, PTR_TO_BUF, and
PTR_TO_TP_BUFFER similarly to PTR_TO_MAP_{KEY,VALUE}. That is, instead of
exact match for var_off and range, use tnum_in() and range_within()
checks, allowing more general verified state to subsume more specific
current state. This allows to match wider range of valid and safe
states, speeding up verification and detecting wider range of equivalent
states for upcoming open-coded iteration looping logic.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-3-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko [Thu, 2 Mar 2023 23:49:59 +0000 (15:49 -0800)]
bpf: improve stack slot state printing
Improve stack slot state printing to provide more useful and relevant
information, especially for dynptrs. While previously we'd see something
like:
8: (85) call bpf_ringbuf_reserve_dynptr#198 ; R0_w=scalar() fp-8_w=
dddddddd fp-16_w=
dddddddd refs=2
Now we'll see way more useful:
8: (85) call bpf_ringbuf_reserve_dynptr#198 ; R0_w=scalar() fp-16_w=dynptr_ringbuf(ref_id=2) refs=2
I experimented with printing the range of slots taken by dynptr,
something like:
fp-16..8_w=dynptr_ringbuf(ref_id=2)
But it felt very awkward and pretty useless. So we print the lowest
address (most negative offset) only.
The general structure of this code is now also set up for easier
extension and will accommodate ITER slots naturally.
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230302235015.2044271-2-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Alexei Starovoitov [Sat, 4 Mar 2023 05:41:46 +0000 (21:41 -0800)]
Merge branch 'bpf: allow ctx writes using BPF_ST_MEM instruction'
Eduard Zingerman says:
====================
Changes v1 -> v2, suggested by Alexei:
- Resolved conflict with recent commit:
6fcd486b3a0a ("bpf: Refactor RCU enforcement in the verifier");
- Variable `ctx_access` removed in function `convert_ctx_accesses()`;
- Macro `BPF_COPY_STORE` renamed to `BPF_EMIT_STORE` and fixed to
correctly extract original store instruction class from code.
Original message follows:
The function verifier.c:convert_ctx_access() applies some rewrites to BPF
instructions that read from or write to the BPF program context.
For example, the write instruction for the `struct bpf_sockopt::retval`
field:
*(u32 *)(r1 + offsetof(struct bpf_sockopt, retval)) = r2
Is transformed to:
*(u64 *)(r1 + offsetof(struct bpf_sockopt_kern, tmp_reg)) = r9
r9 = *(u64 *)(r1 + offsetof(struct bpf_sockopt_kern, current_task))
r9 = *(u64 *)(r9 + offsetof(struct task_struct, bpf_ctx))
*(u32 *)(r9 + offsetof(struct bpf_cg_run_ctx, retval)) = r2
r9 = *(u64 *)(r1 + offsetof(struct bpf_sockopt_kern, tmp_reg))
Currently, the verifier only supports such transformations for LDX
(memory-to-register read) and STX (register-to-memory write) instructions.
Error is reported for ST instructions (immediate-to-memory write).
This is fine because clang does not currently emit ST instructions.
However, new `-mcpu=v4` clang flag is planned, which would allow to emit
ST instructions (discussed in [1]).
This patch-set adjusts the verifier to support ST instructions in
`verifier.c:convert_ctx_access()`.
The patches #1 and #2 were previously shared as part of RFC [2]. The
changes compared to that RFC are:
- In patch #1, a bug in the handling of the
`struct __sk_buff::queue_mapping` field was fixed.
- Patch #3 is added, which is a set of disassembler-based test cases for
context access rewrites. The test cases cover all fields for which the
handling code is modified in patch #1.
[1] Propose some new instructions for -mcpu=v4
https://lore.kernel.org/bpf/
4bfe98be-5333-1c7e-2f6d-
42486c8ec039@meta.com/
[2] RFC Support for BPF_ST instruction in LLVM C compiler
https://lore.kernel.org/bpf/
20221231163122.
1360813-1-eddyz87@gmail.com/
[3] v1
https://lore.kernel.org/bpf/
20230302225507.
3413720-1-eddyz87@gmail.com/
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Eduard Zingerman [Sat, 4 Mar 2023 01:12:47 +0000 (03:12 +0200)]
selftests/bpf: Disassembler tests for verifier.c:convert_ctx_access()
Function verifier.c:convert_ctx_access() applies some rewrites to BPF
instructions that read or write BPF program context. This commit adds
machinery to allow test cases that inspect BPF program after these
rewrites are applied.
An example of a test case:
{
// Shorthand for field offset and size specification
N(CGROUP_SOCKOPT, struct bpf_sockopt, retval),
// Pattern generated for field read
.read = "$dst = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"$dst = *(u64 *)($dst + task_struct::bpf_ctx);"
"$dst = *(u32 *)($dst + bpf_cg_run_ctx::retval);",
// Pattern generated for field write
.write = "*(u64 *)($ctx + bpf_sockopt_kern::tmp_reg) = r9;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::current_task);"
"r9 = *(u64 *)(r9 + task_struct::bpf_ctx);"
"*(u32 *)(r9 + bpf_cg_run_ctx::retval) = $src;"
"r9 = *(u64 *)($ctx + bpf_sockopt_kern::tmp_reg);" ,
},
For each test case, up to three programs are created:
- One that uses BPF_LDX_MEM to read the context field.
- One that uses BPF_STX_MEM to write to the context field.
- One that uses BPF_ST_MEM to write to the context field.
The disassembly of each program is compared with the pattern specified
in the test case.
Kernel code for disassembly is reused (as is in the bpftool).
To keep Makefile changes to the minimum, symbolic links to
`kernel/bpf/disasm.c` and `kernel/bpf/disasm.h ` are added.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-4-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Eduard Zingerman [Sat, 4 Mar 2023 01:12:46 +0000 (03:12 +0200)]
selftests/bpf: test if pointer type is tracked for BPF_ST_MEM
Check that verifier tracks pointer types for BPF_ST_MEM instructions
and reports error if pointer types do not match for different
execution branches.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-3-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Eduard Zingerman [Sat, 4 Mar 2023 01:12:45 +0000 (03:12 +0200)]
bpf: allow ctx writes using BPF_ST_MEM instruction
Lift verifier restriction to use BPF_ST_MEM instructions to write to
context data structures. This requires the following changes:
- verifier.c:do_check() for BPF_ST updated to:
- no longer forbid writes to registers of type PTR_TO_CTX;
- track dst_reg type in the env->insn_aux_data[...].ptr_type field
(same way it is done for BPF_STX and BPF_LDX instructions).
- verifier.c:convert_ctx_access() and various callbacks invoked by
it are updated to handled BPF_ST instruction alongside BPF_STX.
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20230304011247.566040-2-eddyz87@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Kumar Kartikeya Dwivedi [Fri, 3 Mar 2023 14:15:42 +0000 (15:15 +0100)]
bpf: Use separate RCU callbacks for freeing selem
Martin suggested that instead of using a byte in the hole (which he has
a use for in his future patch) in bpf_local_storage_elem, we can
dispatch a different call_rcu callback based on whether we need to free
special fields in bpf_local_storage_elem data. The free path, described
in commit
9db44fdd8105 ("bpf: Support kptrs in local storage maps"),
only waits for call_rcu callbacks when there are special (kptrs, etc.)
fields in the map value, hence it is necessary that we only access
smap in this case.
Therefore, dispatch different RCU callbacks based on the BPF map has a
valid btf_record, which dereference and use smap's btf_record only when
it is valid.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20230303141542.300068-1-memxor@gmail.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Daniel Borkmann [Fri, 3 Mar 2023 16:42:20 +0000 (17:42 +0100)]
Merge branch 'bpf-kptr-rcu'
Alexei Starovoitov says:
====================
v4->v5:
fix typos, add acks.
v3->v4:
- patch 3 got much cleaner after BPF_KPTR_RCU was removed as suggested by David.
- make KF_RCU stronger and require that bpf program checks for NULL
before passing such pointers into kfunc. The prog has to do that anyway
to access fields and it aligns with BTF_TYPE_SAFE_RCU allowlist.
- New patch 6: refactor RCU enforcement in the verifier.
The patches 2,3,6 are part of one feature.
The 2 and 3 alone are incomplete, since RCU pointers are barely useful
without bpf_rcu_read_lock/unlock in GCC compiled kernel.
Even if GCC lands support for btf_type_tag today it will take time
to mandate that version for kernel builds. Hence go with allow list
approach. See patch 6 for details.
This allows to start strict enforcement of TRUSTED | UNTRUSTED
in one part of PTR_TO_BTF_ID accesses.
One step closer to KF_TRUSTED_ARGS by default.
v2->v3:
- Instead of requiring bpf progs to tag fields with __kptr_rcu
teach the verifier to infer RCU properties based on the type.
BPF_KPTR_RCU becomes kernel internal type of struct btf_field.
- Add patch 2 to tag cgroups and dfl_cgrp as trusted.
That bug was spotted by BPF CI on clang compiler kernels,
since patch 3 is doing:
static bool in_rcu_cs(struct bpf_verifier_env *env)
{
return env->cur_state->active_rcu_lock || !env->prog->aux->sleepable;
}
which makes all non-sleepable programs behave like they have implicit
rcu_read_lock around them. Which is the case in practice.
It was fine on gcc compiled kernels where task->cgroup deference was producing
PTR_TO_BTF_ID, but on clang compiled kernels task->cgroup deference was
producing PTR_TO_BTF_ID | MEM_RCU | MAYBE_NULL, which is more correct,
but selftests were failing. Patch 2 fixes this discrepancy.
With few more patches like patch 2 we can make KF_TRUSTED_ARGS default
for kfuncs and helpers.
- Add comment in selftest patch 5 that it's verifier only check.
v1->v2:
Instead of agressively allow dereferenced kptr_rcu pointers into KF_TRUSTED_ARGS
kfuncs only allow them into KF_RCU funcs.
The KF_RCU flag is a weaker version of KF_TRUSTED_ARGS. The kfuncs marked with
KF_RCU expect either PTR_TRUSTED or MEM_RCU arguments. The verifier guarantees
that the objects are valid and there is no use-after-free, but the pointers
maybe NULL and pointee object's reference count could have reached zero, hence
kfuncs must do != NULL check and consider refcnt==0 case when accessing such
arguments.
No changes in patch 1.
Patches 2,3,4 adjusted with above behavior.
v1:
The __kptr_ref turned out to be too limited, since any "trusted" pointer access
requires bpf_kptr_xchg() which is impractical when the same pointer needs
to be dereferenced by multiple cpus.
The __kptr "untrusted" only access isn't very useful in practice.
Rename __kptr to __kptr_untrusted with eventual goal to deprecate it,
and rename __kptr_ref to __kptr, since that looks to be more common use of kptrs.
Introduce __kptr_rcu that can be directly dereferenced and used similar
to native kernel C code.
Once bpf_cpumask and task_struct kfuncs are converted to observe RCU GP
when refcnt goes to zero, both __kptr and __kptr_untrusted can be deprecated
and __kptr_rcu can become the only __kptr tag.
====================
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Alexei Starovoitov [Fri, 3 Mar 2023 04:14:46 +0000 (20:14 -0800)]
bpf: Refactor RCU enforcement in the verifier.
bpf_rcu_read_lock/unlock() are only available in clang compiled kernels. Lack
of such key mechanism makes it impossible for sleepable bpf programs to use RCU
pointers.
Allow bpf_rcu_read_lock/unlock() in GCC compiled kernels (though GCC doesn't
support btf_type_tag yet) and allowlist certain field dereferences in important
data structures like tast_struct, cgroup, socket that are used by sleepable
programs either as RCU pointer or full trusted pointer (which is valid outside
of RCU CS). Use BTF_TYPE_SAFE_RCU and BTF_TYPE_SAFE_TRUSTED macros for such
tagging. They will be removed once GCC supports btf_type_tag.
With that refactor check_ptr_to_btf_access(). Make it strict in enforcing
PTR_TRUSTED and PTR_UNTRUSTED while deprecating old PTR_TO_BTF_ID without
modifier flags. There is a chance that this strict enforcement might break
existing programs (especially on GCC compiled kernels), but this cleanup has to
start sooner than later. Note PTR_TO_CTX access still yields old deprecated
PTR_TO_BTF_ID. Once it's converted to strict PTR_TRUSTED or PTR_UNTRUSTED the
kfuncs and helpers will be able to default to KF_TRUSTED_ARGS. KF_RCU will
remain as a weaker version of KF_TRUSTED_ARGS where obj refcnt could be 0.
Adjust rcu_read_lock selftest to run on gcc and clang compiled kernels.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-7-alexei.starovoitov@gmail.com
Alexei Starovoitov [Fri, 3 Mar 2023 04:14:45 +0000 (20:14 -0800)]
selftests/bpf: Tweak cgroup kfunc test.
Adjust cgroup kfunc test to dereference RCU protected cgroup pointer
as PTR_TRUSTED and pass into KF_TRUSTED_ARGS kfunc.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-6-alexei.starovoitov@gmail.com
Alexei Starovoitov [Fri, 3 Mar 2023 04:14:44 +0000 (20:14 -0800)]
selftests/bpf: Add a test case for kptr_rcu.
Tweak existing map_kptr test to check kptr_rcu.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-5-alexei.starovoitov@gmail.com
Alexei Starovoitov [Fri, 3 Mar 2023 04:14:43 +0000 (20:14 -0800)]
bpf: Introduce kptr_rcu.
The life time of certain kernel structures like 'struct cgroup' is protected by RCU.
Hence it's safe to dereference them directly from __kptr tagged pointers in bpf maps.
The resulting pointer is MEM_RCU and can be passed to kfuncs that expect KF_RCU.
Derefrence of other kptr-s returns PTR_UNTRUSTED.
For example:
struct map_value {
struct cgroup __kptr *cgrp;
};
SEC("tp_btf/cgroup_mkdir")
int BPF_PROG(test_cgrp_get_ancestors, struct cgroup *cgrp_arg, const char *path)
{
struct cgroup *cg, *cg2;
cg = bpf_cgroup_acquire(cgrp_arg); // cg is PTR_TRUSTED and ref_obj_id > 0
bpf_kptr_xchg(&v->cgrp, cg);
cg2 = v->cgrp; // This is new feature introduced by this patch.
// cg2 is PTR_MAYBE_NULL | MEM_RCU.
// When cg2 != NULL, it's a valid cgroup, but its percpu_ref could be zero
if (cg2)
bpf_cgroup_ancestor(cg2, level); // safe to do.
}
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-4-alexei.starovoitov@gmail.com
Alexei Starovoitov [Fri, 3 Mar 2023 04:14:42 +0000 (20:14 -0800)]
bpf: Mark cgroups and dfl_cgrp fields as trusted.
bpf programs sometimes do:
bpf_cgrp_storage_get(&map, task->cgroups->dfl_cgrp, ...);
It is safe to do, because cgroups->dfl_cgrp pointer is set diring init and
never changes. The task->cgroups is also never NULL. It is also set during init
and will change when task switches cgroups. For any trusted task pointer
dereference of cgroups and dfl_cgrp should yield trusted pointers. The verifier
wasn't aware of this. Hence in gcc compiled kernels task->cgroups dereference
was producing PTR_TO_BTF_ID without modifiers while in clang compiled kernels
the verifier recognizes __rcu tag in cgroups field and produces
PTR_TO_BTF_ID | MEM_RCU | MAYBE_NULL.
Tag cgroups and dfl_cgrp as trusted to equalize clang and gcc behavior.
When GCC supports btf_type_tag such tagging will done directly in the type.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Acked-by: Tejun Heo <tj@kernel.org>
Link: https://lore.kernel.org/bpf/20230303041446.3630-3-alexei.starovoitov@gmail.com
Alexei Starovoitov [Fri, 3 Mar 2023 04:14:41 +0000 (20:14 -0800)]
bpf: Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted.
__kptr meant to store PTR_UNTRUSTED kernel pointers inside bpf maps.
The concept felt useful, but didn't get much traction,
since bpf_rdonly_cast() was added soon after and bpf programs received
a simpler way to access PTR_UNTRUSTED kernel pointers
without going through restrictive __kptr usage.
Rename __kptr_ref -> __kptr and __kptr -> __kptr_untrusted to indicate
its intended usage.
The main goal of __kptr_untrusted was to read/write such pointers
directly while bpf_kptr_xchg was a mechanism to access refcnted
kernel pointers. The next patch will allow RCU protected __kptr access
with direct read. At that point __kptr_untrusted will be deprecated.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230303041446.3630-2-alexei.starovoitov@gmail.com
Tero Kristo [Thu, 2 Mar 2023 11:46:14 +0000 (13:46 +0200)]
selftests/bpf: Add absolute timer test
Add test for the absolute BPF timer under the existing timer tests. This
will run the timer two times with 1us expiration time, and then re-arm
the timer at ~35s in the future. At the end, it is verified that the
absolute timer expired exactly two times.
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Link: https://lore.kernel.org/r/20230302114614.2985072-3-tero.kristo@linux.intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tero Kristo [Thu, 2 Mar 2023 11:46:13 +0000 (13:46 +0200)]
bpf: Add support for absolute value BPF timers
Add a new flag BPF_F_TIMER_ABS that can be passed to bpf_timer_start()
to start an absolute value timer instead of the default relative value.
This makes the timer expire at an exact point in time, instead of a time
with latencies induced by both the BPF and timer subsystems.
Suggested-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>
Signed-off-by: Tero Kristo <tero.kristo@linux.intel.com>
Link: https://lore.kernel.org/r/20230302114614.2985072-2-tero.kristo@linux.intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Dave Marchevsky [Fri, 3 Mar 2023 00:55:00 +0000 (16:55 -0800)]
selftests/bpf: Add -Wuninitialized flag to bpf prog flags
Per C99 standard [0], Section 6.7.8, Paragraph 10:
If an object that has automatic storage duration is not initialized
explicitly, its value is indeterminate.
And in the same document, in appendix "J.2 Undefined behavior":
The behavior is undefined in the following circumstances:
[...]
The value of an object with automatic storage duration is used while
it is indeterminate (6.2.4, 6.7.8, 6.8).
This means that use of an uninitialized stack variable is undefined
behavior, and therefore that clang can choose to do a variety of scary
things, such as not generating bytecode for "bunch of useful code" in
the below example:
void some_func()
{
int i;
if (!i)
return;
// bunch of useful code
}
To add insult to injury, if some_func above is a helper function for
some BPF program, clang can choose to not generate an "exit" insn,
causing verifier to fail with "last insn is not an exit or jmp". Going
from that verification failure to the root cause of uninitialized use
is certain to be frustrating.
This patch adds -Wuninitialized to the cflags for selftest BPF progs and
fixes up existing instances of uninitialized use.
[0]: https://www.open-std.org/jtc1/sc22/WG14/www/docs/n1256.pdf
Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com>
Cc: David Vernet <void@manifault.com>
Cc: Tejun Heo <tj@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230303005500.1614874-1-davemarchevsky@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Tejun Heo [Thu, 2 Mar 2023 19:42:59 +0000 (09:42 -1000)]
bpf: Make bpf_get_current_[ancestor_]cgroup_id() available for all program types
These helpers are safe to call from any context and there's no reason to
restrict access to them. Remove them from bpf_trace and filter lists and add
to bpf_base_func_proto() under perfmon_capable().
v2: After consulting with Andrii, relocated in bpf_base_func_proto() so that
they require bpf_capable() but not perfomon_capable() as it doesn't read
from or affect others on the system.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/ZAD8QyoszMZiTzBY@slm.duckdns.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
David Vernet [Thu, 2 Mar 2023 18:39:18 +0000 (12:39 -0600)]
bpf, docs: Fix final bpf docs build failure
maps.rst in the BPF documentation links to the
/userspace-api/ebpf/syscall document
(Documentation/userspace-api/ebpf/syscall.rst). For some reason, if you
try to reference the document with :doc:, the docs build emits the
following warning:
./Documentation/bpf/maps.rst:13: WARNING: \
unknown document: '/userspace-api/ebpf/syscall'
It appears that other places in the docs tree also don't support using
:doc:. Elsewhere in the BPF documentation, we just reference the kernel
docs page directly. Let's do that here to clean up the last remaining
noise in the docs build.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230302183918.54190-2-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
David Vernet [Thu, 2 Mar 2023 18:39:17 +0000 (12:39 -0600)]
bpf, docs: Fix link to netdev-FAQ target
The BPF devel Q&A documentation page makes frequent reference to the
netdev-QA page via the netdev-FAQ rst link. This link is currently
broken, as is evidenced by the build output when making BPF docs:
./Documentation/bpf/bpf_devel_QA.rst:150: WARNING: undefined label: 'netdev-faq'
./Documentation/bpf/bpf_devel_QA.rst:206: WARNING: undefined label: 'netdev-faq'
./Documentation/bpf/bpf_devel_QA.rst:231: WARNING: undefined label: 'netdev-faq'
./Documentation/bpf/bpf_devel_QA.rst:396: WARNING: undefined label: 'netdev-faq'
./Documentation/bpf/bpf_devel_QA.rst:412: WARNING: undefined label: 'netdev-faq'
Fix the links to point to the actual netdev-faq page.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230302183918.54190-1-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Joanne Koong [Thu, 2 Mar 2023 05:30:14 +0000 (21:30 -0800)]
bpf: Fix bpf_dynptr_slice{_rdwr} to return NULL instead of 0
Change bpf_dynptr_slice and bpf_dynptr_slice_rdwr to return NULL instead
of 0, in accordance with the codebase guidelines.
Fixes:
66e3a13e7c2c ("bpf: Add bpf_dynptr_slice and bpf_dynptr_slice_rdwr")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Joanne Koong <joannelkoong@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230302053014.1726219-1-joannelkoong@gmail.com
Andrii Nakryiko [Thu, 2 Mar 2023 00:05:35 +0000 (16:05 -0800)]
Merge branch 'Make uprobe attachment APK aware'
Daniel Müller says:
====================
On Android, APKs (android packages; zip packages with somewhat
prescriptive contents) are first class citizens in the system: the
shared objects contained in them don't exist in unpacked form on the
file system. Rather, they are mmaped directly from within the archive
and the archive is also what the kernel is aware of.
For users that complicates the process of attaching a uprobe to a
function contained in a shared object in one such APK: they'd have to
find the byte offset of said function from the beginning of the archive.
That is cumbersome to do manually and can be fragile, because various
changes could invalidate said offset.
That is why for uprobes inside ELF files (not inside an APK), commit
d112c9ce249b ("libbpf: Support function name-based attach uprobes") added
support for attaching to symbols by name. On Android, that mechanism
currently does not work, because this logic is not APK aware.
This patch set introduces first class support for attaching uprobes to
functions inside ELF objects contained in APKs via function names. We
add support for recognizing the following syntax for a binary path:
<archive>!/<binary-in-archive>
(e.g., /system/app/test-app.apk!/lib/arm64-v8a/libc++.so)
This syntax is common in the Android eco system and used by tools such
as simpleperf. It is also what is being proposed for bcc [0].
If the user provides such a binary path, we find <binary-in-archive>
(lib/arm64-v8a/libc++.so in the example) inside of <archive>
(/system/app/test-app.apk). We perform the regular ELF offset search
inside the binary and add that to the offset within the archive itself,
to retrieve the offset at which to attach the uprobe.
[0] https://github.com/iovisor/bcc/pull/4440
Changelog
---------
v3->v4:
- use ERR_PTR instead of libbpf_err_ptr() in zip_archive_open()
- eliminated err variable from elf_find_func_offset_from_archive()
v2->v3:
- adjusted zip_archive_open() to report errno
- fixed provided libbpf_strlcpy() buffer size argument
- adjusted find_cd() to handle errors better
- use fewer local variables in get_entry_at_offset()
v1->v2:
- removed unaligned_* types
- switched to using __u32 and __u16
- switched to using errno constants instead of hard-coded negative values
- added another pr_debug() message
- shortened central_directory_* to cd_*
- inlined cd_file_header_at_offset() function
- bunch of syntactical changes
====================
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Daniel Müller [Wed, 1 Mar 2023 21:23:08 +0000 (21:23 +0000)]
libbpf: Add support for attaching uprobes to shared objects in APKs
This change adds support for attaching uprobes to shared objects located
in APKs, which is relevant for Android systems where various libraries
may reside in APKs. To make that happen, we extend the syntax for the
"binary path" argument to attach to with that supported by various
Android tools:
<archive>!/<binary-in-archive>
For example:
/system/app/test-app/test-app.apk!/lib/arm64-v8a/libc++_shared.so
APKs need to be specified via full path, i.e., we do not attempt to
resolve mere file names by searching system directories.
We cannot currently test this functionality end-to-end in an automated
fashion, because it relies on an Android system being present, but there
is no support for that in CI. I have tested the functionality manually,
by creating a libbpf program containing a uretprobe, attaching it to a
function inside a shared object inside an APK, and verifying the sanity
of the returned values.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230301212308.1839139-4-deso@posteo.net
Daniel Müller [Wed, 1 Mar 2023 21:23:07 +0000 (21:23 +0000)]
libbpf: Introduce elf_find_func_offset_from_file() function
This change splits the elf_find_func_offset() function in two:
elf_find_func_offset(), which now accepts an already opened Elf object
instead of a path to a file that is to be opened, as well as
elf_find_func_offset_from_file(), which opens a binary based on a
path and then invokes elf_find_func_offset() on the Elf object. Having
this split in responsibilities will allow us to call
elf_find_func_offset() from other code paths on Elf objects that did not
necessarily come from a file on disk.
Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230301212308.1839139-3-deso@posteo.net