[ Upstream commit b16904fd9f01b580db357ef2b1cc9e86d89576c2 ]
With latest upstream llvm18, the following test cases failed:
$ ./test_progs -j
#13/2 bpf_cookie/multi_kprobe_link_api:FAIL
#13/3 bpf_cookie/multi_kprobe_attach_api:FAIL
#13 bpf_cookie:FAIL
#77 fentry_fexit:FAIL
#78/1 fentry_test/fentry:FAIL
#78 fentry_test:FAIL
#82/1 fexit_test/fexit:FAIL
#82 fexit_test:FAIL
#112/1 kprobe_multi_test/skel_api:FAIL
#112/2 kprobe_multi_test/link_api_addrs:FAIL
[...]
#112 kprobe_multi_test:FAIL
#356/17 test_global_funcs/global_func17:FAIL
#356 test_global_funcs:FAIL
Further analysis shows llvm upstream patch [1] is responsible for the above
failures. For example, for function bpf_fentry_test7() in net/bpf/test_run.c,
without [1], the asm code is:
0000000000000400 <bpf_fentry_test7>:
400: f3 0f 1e fa endbr64
404: e8 00 00 00 00 callq 0x409 <bpf_fentry_test7+0x9>
409: 48 89 f8 movq %rdi, %rax
40c: c3 retq
40d: 0f 1f 00 nopl (%rax)
... and with [1], the asm code is:
0000000000005d20 <bpf_fentry_test7.specialized.1>:
5d20: e8 00 00 00 00 callq 0x5d25 <bpf_fentry_test7.specialized.1+0x5>
5d25: c3 retq
... and <bpf_fentry_test7.specialized.1> is called instead of <bpf_fentry_test7>
and this caused test failures for #13/#77 etc. except #356.
For test case #356/17, with [1] (progs/test_global_func17.c)), the main prog
looks like:
0000000000000000 <global_func17>:
0: b4 00 00 00 2a 00 00 00 w0 = 0x2a
1: 95 00 00 00 00 00 00 00 exit
... which passed verification while the test itself expects a verification
failure.
Let us add 'barrier_var' style asm code in both places to prevent function
specialization which caused selftests failure.
[1] https://github.com/llvm/llvm-project/pull/72903
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20231127050342.1945270-1-yonghong.song@linux.dev
Signed-off-by: Sasha Levin <sashal@kernel.org>
With latest clang18, I hit test_progs failures for the following test:
#13/2 bpf_cookie/multi_kprobe_link_api:FAIL
#13/3 bpf_cookie/multi_kprobe_attach_api:FAIL
#13 bpf_cookie:FAIL
#75 fentry_fexit:FAIL
#76/1 fentry_test/fentry:FAIL
#76 fentry_test:FAIL
#80/1 fexit_test/fexit:FAIL
#80 fexit_test:FAIL
#110/1 kprobe_multi_test/skel_api:FAIL
#110/2 kprobe_multi_test/link_api_addrs:FAIL
#110/3 kprobe_multi_test/link_api_syms:FAIL
#110/4 kprobe_multi_test/attach_api_pattern:FAIL
#110/5 kprobe_multi_test/attach_api_addrs:FAIL
#110/6 kprobe_multi_test/attach_api_syms:FAIL
#110 kprobe_multi_test:FAIL
For example, for #13/2, the error messages are:
[...]
kprobe_multi_test_run:FAIL:kprobe_test7_result unexpected kprobe_test7_result: actual 0 != expected 1
[...]
kprobe_multi_test_run:FAIL:kretprobe_test7_result unexpected kretprobe_test7_result: actual 0 != expected 1
clang17 does not have this issue.
Further investigation shows that kernel func bpf_fentry_test7(), used in
the above tests, is inlined by the compiler although it is marked as
noinline.
int noinline bpf_fentry_test7(struct bpf_fentry_test_t *arg)
{
return (long)arg;
}
It is known that for simple functions like the above (e.g. just returning
a constant or an input argument), the clang compiler may still do inlining
for a noinline function. Adding 'asm volatile ("")' in the beginning of the
bpf_fentry_test7() can prevent inlining.
Signed-off-by: Yonghong Song <yonghong.song@linux.dev>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/bpf/20230826200843.2210074-1-yonghong.song@linux.dev
Split types and pure function declarations from page_pool.h
and add them in page_page/types.h, so that C sources can
include page_pool.h and headers should generally only include
page_pool/types.h as suggested by jakub.
Rename page_pool.h to page_pool/helpers.h to have both in
one place.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Link: https://lore.kernel.org/r/20230804180529.2483231-2-aleksander.lobakin@intel.com
[Jakub: change microsoft/mana, fix kdoc paths in Documentation]
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
struct netdev_rx_queue is touched in only a few places
and having it defined in netdevice.h brings in the dependency
on xdp.h, because struct xdp_rxq_info gets embedded in
struct netdev_rx_queue.
In prep for removal of xdp.h from netdevice.h move all
the netdev_rx_queue stuff to a new header.
We could technically break the new header up to avoid
the sysfs.h include but it's so rarely included it
doesn't seem to be worth it at this point.
Reviewed-by: Amritha Nambiar <amritha.nambiar@intel.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Jesper Dangaard Brouer <hawk@kernel.org>
Link: https://lore.kernel.org/r/20230803010230.1755386-3-kuba@kernel.org
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Add fentry_many_args.c and fexit_many_args.c to test the fentry/fexit
with 7/11 arguments. As this feature is not supported by arm64 yet, we
disable these testcases for arm64 in DENYLIST.aarch64. We can combine
them with fentry_test.c/fexit_test.c when arm64 is supported too.
Correspondingly, add bpf_testmod_fentry_test7() and
bpf_testmod_fentry_test11() to bpf_testmod.c
Meanwhile, add bpf_modify_return_test2() to test_run.c to test the
MODIFY_RETURN with 7 arguments.
Add bpf_testmod_test_struct_arg_7/bpf_testmod_test_struct_arg_7 in
bpf_testmod.c to test the struct in the arguments.
And the testcases passed on x86_64:
./test_progs -t fexit
Summary: 5/14 PASSED, 0 SKIPPED, 0 FAILED
./test_progs -t fentry
Summary: 3/2 PASSED, 0 SKIPPED, 0 FAILED
./test_progs -t modify_return
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
./test_progs -t tracing_struct
Summary: 1/0 PASSED, 0 SKIPPED, 0 FAILED
Signed-off-by: Menglong Dong <imagedong@tencent.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230713040738.1789742-4-imagedong@tencent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Add new bpf_fentry_test_sinfo with skb_shared_info argument and try to
access frags.
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/bpf/20230626212522.2414485-2-sdf@google.com
Moving kernel test kfuncs into bpf_testmod kernel module, and adding
necessary init calls and BTF IDs records.
We need to keep following structs in kernel:
struct prog_test_ref_kfunc
struct prog_test_member (embedded in prog_test_ref_kfunc)
The reason is because they need to be marked as rcu safe (check test
prog mark_ref_as_untrusted_or_null) and such objects are being required
to be defined only in kernel at the moment (see rcu_safe_kptr check
in kernel).
We need to keep also dtor functions for both objects in kernel:
bpf_kfunc_call_test_release
bpf_kfunc_call_memb_release
We also keep the copy of these struct in bpf_testmod_kfunc.h, because
other test functions use them. This is unfortunate, but this is just
temporary solution until we are able to these structs them to bpf_testmod
completely.
As suggested by David adding bpf_testmod.ko make dependency for
bpf programs, so they are rebuilt if we change the bpf_testmod.ko
module.
Also adding missing __bpf_kfunc to bpf_kfunc_call_test4 functions.
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230515133756.1658301-11-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Most users use __skb_frag_set_page()/skb_frag_off_set()/
skb_frag_size_set() to fill the page desc for a skb frag.
Introduce skb_frag_fill_page_desc() to do that.
net/bpf/test_run.c does not call skb_frag_off_set() to
set the offset, "copy_from_user(page_address(page), ...)"
and 'shinfo' being part of the 'data' kzalloced in
bpf_test_init() suggest that it is assuming offset to be
initialized as zero, so call skb_frag_fill_page_desc()
with offset being zero for this case.
Also, skb_frag_set_page() is not used anymore, so remove
it.
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
add glue code so a bpf program can be run using userspace-provided
netfilter state and packet/skb.
Default is to use ipv4:output hook point, but this can be overridden by
userspace. Userspace provided netfilter state is restricted, only hook and
protocol families can be overridden and only to ipv4/ipv6.
Signed-off-by: Florian Westphal <fw@strlen.de>
Link: https://lore.kernel.org/r/20230421170300.24115-7-fw@strlen.de
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We've managed to improve the UX for kptrs significantly over the last 9
months. All of the prior main use cases, struct bpf_cpumask *, struct
task_struct *, and struct cgroup *, have all been updated to be
synchronized mainly using RCU. In other words, their KF_ACQUIRE kfunc
calls are all KF_RCU, and the pointers themselves are MEM_RCU and can be
accessed in an RCU read region in BPF.
In a follow-on change, we'll be removing the KF_KPTR_GET kfunc flag.
This patch prepares for that by removing the
bpf_kfunc_call_test_kptr_get() kfunc, and all associated selftests.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230416084928.326135-2-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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Daniel Borkmann says:
====================
pull-request: bpf-next 2023-04-13
We've added 260 non-merge commits during the last 36 day(s) which contain
a total of 356 files changed, 21786 insertions(+), 11275 deletions(-).
The main changes are:
1) Rework BPF verifier log behavior and implement it as a rotating log
by default with the option to retain old-style fixed log behavior,
from Andrii Nakryiko.
2) Adds support for using {FOU,GUE} encap with an ipip device operating
in collect_md mode and add a set of BPF kfuncs for controlling encap
params, from Christian Ehrig.
3) Allow BPF programs to detect at load time whether a particular kfunc
exists or not, and also add support for this in light skeleton,
from Alexei Starovoitov.
4) Optimize hashmap lookups when key size is multiple of 4,
from Anton Protopopov.
5) Enable RCU semantics for task BPF kptrs and allow referenced kptr
tasks to be stored in BPF maps, from David Vernet.
6) Add support for stashing local BPF kptr into a map value via
bpf_kptr_xchg(). This is useful e.g. for rbtree node creation
for new cgroups, from Dave Marchevsky.
7) Fix BTF handling of is_int_ptr to skip modifiers to work around
tracing issues where a program cannot be attached, from Feng Zhou.
8) Migrate a big portion of test_verifier unit tests over to
test_progs -a verifier_* via inline asm to ease {read,debug}ability,
from Eduard Zingerman.
9) Several updates to the instruction-set.rst documentation
which is subject to future IETF standardization
(https://lwn.net/Articles/926882/), from Dave Thaler.
10) Fix BPF verifier in the __reg_bound_offset's 64->32 tnum sub-register
known bits information propagation, from Daniel Borkmann.
11) Add skb bitfield compaction work related to BPF with the overall goal
to make more of the sk_buff bits optional, from Jakub Kicinski.
12) BPF selftest cleanups for build id extraction which stand on its own
from the upcoming integration work of build id into struct file object,
from Jiri Olsa.
13) Add fixes and optimizations for xsk descriptor validation and several
selftest improvements for xsk sockets, from Kal Conley.
14) Add BPF links for struct_ops and enable switching implementations
of BPF TCP cong-ctls under a given name by replacing backing
struct_ops map, from Kui-Feng Lee.
15) Remove a misleading BPF verifier env->bypass_spec_v1 check on variable
offset stack read as earlier Spectre checks cover this,
from Luis Gerhorst.
16) Fix issues in copy_from_user_nofault() for BPF and other tracers
to resemble copy_from_user_nmi() from safety PoV, from Florian Lehner
and Alexei Starovoitov.
17) Add --json-summary option to test_progs in order for CI tooling to
ease parsing of test results, from Manu Bretelle.
18) Batch of improvements and refactoring to prep for upcoming
bpf_local_storage conversion to bpf_mem_cache_{alloc,free} allocator,
from Martin KaFai Lau.
19) Improve bpftool's visual program dump which produces the control
flow graph in a DOT format by adding C source inline annotations,
from Quentin Monnet.
20) Fix attaching fentry/fexit/fmod_ret/lsm to modules by extracting
the module name from BTF of the target and searching kallsyms of
the correct module, from Viktor Malik.
21) Improve BPF verifier handling of '<const> <cond> <non_const>'
to better detect whether in particular jmp32 branches are taken,
from Yonghong Song.
22) Allow BPF TCP cong-ctls to write app_limited of struct tcp_sock.
A built-in cc or one from a kernel module is already able to write
to app_limited, from Yixin Shen.
Conflicts:
Documentation/bpf/bpf_devel_QA.rst
b7abcd9c65 ("bpf, doc: Link to submitting-patches.rst for general patch submission info")
0f10f647f4 ("bpf, docs: Use internal linking for link to netdev subsystem doc")
https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/
include/net/ip_tunnels.h
bc9d003dc4 ("ip_tunnel: Preserve pointer const in ip_tunnel_info_opts")
ac931d4cde ("ipip,ip_tunnel,sit: Add FOU support for externally controlled ipip devices")
https://lore.kernel.org/all/20230413161235.4093777-1-broonie@kernel.org/
net/bpf/test_run.c
e5995bc7e2 ("bpf, test_run: fix crashes due to XDP frame overwriting/corruption")
294635a816 ("bpf, test_run: fix &xdp_frame misplacement for LIVE_FRAMES")
https://lore.kernel.org/all/20230320102619.05b80a98@canb.auug.org.au/
====================
Link: https://lore.kernel.org/r/20230413191525.7295-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Adding verifier test for accessing u32 pointer argument in
tracing programs.
The test program loads 1nd argument of bpf_fentry_test9 function
which is u32 pointer and checks that verifier allows that.
Co-developed-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/bpf/20230410085908.98493-3-zhoufeng.zf@bytedance.com
Remove duplicated if (atype == BPF_READ) btf_struct_access() from
btf_struct_access() callback and invoke it only for writes. This is
possible to do because currently btf_struct_access() custom callback
always delegates to generic btf_struct_access() helper for BPF_READ
accesses.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/bpf/20230404045029.82870-2-alexei.starovoitov@gmail.com
KF_RELEASE kfuncs are not currently treated as having KF_TRUSTED_ARGS,
even though they have a superset of the requirements of KF_TRUSTED_ARGS.
Like KF_TRUSTED_ARGS, KF_RELEASE kfuncs require a 0-offset argument, and
don't allow NULL-able arguments. Unlike KF_TRUSTED_ARGS which require
_either_ an argument with ref_obj_id > 0, _or_ (ref->type &
BPF_REG_TRUSTED_MODIFIERS) (and no unsafe modifiers allowed), KF_RELEASE
only allows for ref_obj_id > 0. Because KF_RELEASE today doesn't
automatically imply KF_TRUSTED_ARGS, some of these requirements are
enforced in different ways that can make the behavior of the verifier
feel unpredictable. For example, a KF_RELEASE kfunc with a NULL-able
argument will currently fail in the verifier with a message like, "arg#0
is ptr_or_null_ expected ptr_ or socket" rather than "Possibly NULL
pointer passed to trusted arg0". Our intention is the same, but the
semantics are different due to implemenetation details that kfunc authors
and BPF program writers should not need to care about.
Let's make the behavior of the verifier more consistent and intuitive by
having KF_RELEASE kfuncs imply the presence of KF_TRUSTED_ARGS. Our
eventual goal is to have all kfuncs assume KF_TRUSTED_ARGS by default
anyways, so this takes us a step in that direction.
Note that it does not make sense to assume KF_TRUSTED_ARGS for all
KF_ACQUIRE kfuncs. KF_ACQUIRE kfuncs can have looser semantics than
KF_RELEASE, with e.g. KF_RCU | KF_RET_NULL. We may want to have
KF_ACQUIRE imply KF_TRUSTED_ARGS _unless_ KF_RCU is specified, but that
can be left to another patch set, and there are no such subtleties to
address for KF_RELEASE.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230325213144.486885-4-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Now that we're not invoking kfunc destructors when the kptr in a map was
NULL, we no longer require NULL checks in many of our KF_RELEASE kfuncs.
This patch removes those NULL checks.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230325213144.486885-3-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
syzbot and Ilya faced the splats when %XDP_PASS happens for bpf_test_run
after skb PP recycling was enabled for {__,}xdp_build_skb_from_frame():
BUG: kernel NULL pointer dereference, address: 0000000000000d28
RIP: 0010:memset_erms+0xd/0x20 arch/x86/lib/memset_64.S:66
[...]
Call Trace:
<TASK>
__finalize_skb_around net/core/skbuff.c:321 [inline]
__build_skb_around+0x232/0x3a0 net/core/skbuff.c:379
build_skb_around+0x32/0x290 net/core/skbuff.c:444
__xdp_build_skb_from_frame+0x121/0x760 net/core/xdp.c:622
xdp_recv_frames net/bpf/test_run.c:248 [inline]
xdp_test_run_batch net/bpf/test_run.c:334 [inline]
bpf_test_run_xdp_live+0x1289/0x1930 net/bpf/test_run.c:362
bpf_prog_test_run_xdp+0xa05/0x14e0 net/bpf/test_run.c:1418
[...]
This happens due to that it calls xdp_scrub_frame(), which nullifies
xdpf->data. bpf_test_run code doesn't reinit the frame when the XDP
program doesn't adjust head or tail. Previously, %XDP_PASS meant the
page will be released from the pool and returned to the MM layer, but
now it does return to the Pool with the nullified xdpf->data, which
doesn't get reinitialized then.
So, in addition to checking whether the head and/or tail have been
adjusted, check also for a potential XDP frame corruption. xdpf->data
is 100% affected and also xdpf->flags is the field closest to the
metadata / frame start. Checking for these two should be enough for
non-extreme cases.
Fixes: 9c94bbf9a8 ("xdp: recycle Page Pool backed skbs built from XDP frames")
Reported-by: syzbot+e1d1b65f7c32f2a86a9f@syzkaller.appspotmail.com
Link: https://lore.kernel.org/bpf/000000000000f1985705f6ef2243@google.com
Reported-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/bpf/e07dd94022ad5731705891b9487cc9ed66328b94.camel@linux.ibm.com
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230316175051.922550-2-aleksander.lobakin@intel.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Adds a new test that tries to attach a program to fentry of two
functions of the same name, one located in vmlinux and the other in
bpf_testmod.
To avoid conflicts with existing tests, a new function
"bpf_fentry_shadow_test" was created both in vmlinux and in bpf_testmod.
The previous commit fixed a bug which caused this test to fail. The
verifier would always use the vmlinux function's address as the target
trampoline address, hence trying to create two trampolines for a single
address, which is forbidden.
The test (similarly to other fentry/fexit tests) is not working on arm64
at the moment.
Signed-off-by: Viktor Malik <vmalik@redhat.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/5fe2f364190b6f79b085066ed7c5989c5bc475fa.1678432753.git.vmalik@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
&xdp_buff and &xdp_frame are bound in a way that
xdp_buff->data_hard_start == xdp_frame
It's always the case and e.g. xdp_convert_buff_to_frame() relies on
this.
IOW, the following:
for (u32 i = 0; i < 0xdead; i++) {
xdpf = xdp_convert_buff_to_frame(&xdp);
xdp_convert_frame_to_buff(xdpf, &xdp);
}
shouldn't ever modify @xdpf's contents or the pointer itself.
However, "live packet" code wrongly treats &xdp_frame as part of its
context placed *before* the data_hard_start. With such flow,
data_hard_start is sizeof(*xdpf) off to the right and no longer points
to the XDP frame.
Instead of replacing `sizeof(ctx)` with `offsetof(ctx, xdpf)` in several
places and praying that there are no more miscalcs left somewhere in the
code, unionize ::frm with ::data in a flex array, so that both starts
pointing to the actual data_hard_start and the XDP frame actually starts
being a part of it, i.e. a part of the headroom, not the context.
A nice side effect is that the maximum frame size for this mode gets
increased by 40 bytes, as xdp_buff::frame_sz includes everything from
data_hard_start (-> includes xdpf already) to the end of XDP/skb shared
info.
Also update %MAX_PKT_SIZE accordingly in the selftests code. Leave it
hardcoded for 64 bit && 4k pages, it can be made more flexible later on.
Minor: align `&head->data` with how `head->frm` is assigned for
consistency.
Minor #2: rename 'frm' to 'frame' in &xdp_page_head while at it for
clarity.
(was found while testing XDP traffic generator on ice, which calls
xdp_convert_frame_to_buff() for each XDP frame)
Fixes: b530e9e106 ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20230224163607.2994755-1-aleksander.lobakin@intel.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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
Some of the bpf helpers require bh disabled. eg. The bpf_fib_lookup
helper that will be used in a latter selftest. In particular, it
calls ___neigh_lookup_noref that expects the bh disabled.
This patch disables bh before calling bpf_prog_run[_xdp], so
the testing prog can also use those helpers.
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230217004150.2980689-2-martin.lau@linux.dev
&xdp_buff and &xdp_frame are bound in a way that
xdp_buff->data_hard_start == xdp_frame
It's always the case and e.g. xdp_convert_buff_to_frame() relies on
this.
IOW, the following:
for (u32 i = 0; i < 0xdead; i++) {
xdpf = xdp_convert_buff_to_frame(&xdp);
xdp_convert_frame_to_buff(xdpf, &xdp);
}
shouldn't ever modify @xdpf's contents or the pointer itself.
However, "live packet" code wrongly treats &xdp_frame as part of its
context placed *before* the data_hard_start. With such flow,
data_hard_start is sizeof(*xdpf) off to the right and no longer points
to the XDP frame.
Instead of replacing `sizeof(ctx)` with `offsetof(ctx, xdpf)` in several
places and praying that there are no more miscalcs left somewhere in the
code, unionize ::frm with ::data in a flex array, so that both starts
pointing to the actual data_hard_start and the XDP frame actually starts
being a part of it, i.e. a part of the headroom, not the context.
A nice side effect is that the maximum frame size for this mode gets
increased by 40 bytes, as xdp_buff::frame_sz includes everything from
data_hard_start (-> includes xdpf already) to the end of XDP/skb shared
info.
Also update %MAX_PKT_SIZE accordingly in the selftests code. Leave it
hardcoded for 64 bit && 4k pages, it can be made more flexible later on.
Minor: align `&head->data` with how `head->frm` is assigned for
consistency.
Minor #2: rename 'frm' to 'frame' in &xdp_page_head while at it for
clarity.
(was found while testing XDP traffic generator on ice, which calls
xdp_convert_frame_to_buff() for each XDP frame)
Fixes: b530e9e106 ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Acked-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexander Lobakin <aleksander.lobakin@intel.com>
Link: https://lore.kernel.org/r/20230215185440.4126672-1-aleksander.lobakin@intel.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
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Daniel Borkmann says:
====================
pull-request: bpf-next 2023-02-11
We've added 96 non-merge commits during the last 14 day(s) which contain
a total of 152 files changed, 4884 insertions(+), 962 deletions(-).
There is a minor conflict in drivers/net/ethernet/intel/ice/ice_main.c
between commit 5b246e533d ("ice: split probe into smaller functions")
from the net-next tree and commit 66c0e13ad2 ("drivers: net: turn on
XDP features") from the bpf-next tree. Remove the hunk given ice_cfg_netdev()
is otherwise there a 2nd time, and add XDP features to the existing
ice_cfg_netdev() one:
[...]
ice_set_netdev_features(netdev);
netdev->xdp_features = NETDEV_XDP_ACT_BASIC | NETDEV_XDP_ACT_REDIRECT |
NETDEV_XDP_ACT_XSK_ZEROCOPY;
ice_set_ops(netdev);
[...]
Stephen's merge conflict mail:
https://lore.kernel.org/bpf/20230207101951.21a114fa@canb.auug.org.au/
The main changes are:
1) Add support for BPF trampoline on s390x which finally allows to remove many
test cases from the BPF CI's DENYLIST.s390x, from Ilya Leoshkevich.
2) Add multi-buffer XDP support to ice driver, from Maciej Fijalkowski.
3) Add capability to export the XDP features supported by the NIC.
Along with that, add a XDP compliance test tool,
from Lorenzo Bianconi & Marek Majtyka.
4) Add __bpf_kfunc tag for marking kernel functions as kfuncs,
from David Vernet.
5) Add a deep dive documentation about the verifier's register
liveness tracking algorithm, from Eduard Zingerman.
6) Fix and follow-up cleanups for resolve_btfids to be compiled
as a host program to avoid cross compile issues,
from Jiri Olsa & Ian Rogers.
7) Batch of fixes to the BPF selftest for xdp_hw_metadata which resulted
when testing on different NICs, from Jesper Dangaard Brouer.
8) Fix libbpf to better detect kernel version code on Debian, from Hao Xiang.
9) Extend libbpf to add an option for when the perf buffer should
wake up, from Jon Doron.
10) Follow-up fix on xdp_metadata selftest to just consume on TX
completion, from Stanislav Fomichev.
11) Extend the kfuncs.rst document with description on kfunc
lifecycle & stability expectations, from David Vernet.
12) Fix bpftool prog profile to skip attaching to offline CPUs,
from Tonghao Zhang.
====================
Link: https://lore.kernel.org/r/20230211002037.8489-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
skbuff_head_cache is misnamed (perhaps for historical reasons?)
because it does not hold heads. Head is the buffer which skb->data
points to, and also where shinfo lives. struct sk_buff is a metadata
structure, not the head.
Eric recently added skb_small_head_cache (which allocates actual
head buffers), let that serve as an excuse to finally clean this up :)
Leave the user-space visible name intact, it could possibly be uAPI.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
kfuncs are allowed to be static, or not use one or more of their
arguments. For example, bpf_xdp_metadata_rx_hash() in net/core/xdp.c is
meant to be implemented by drivers, with the default implementation just
returning -EOPNOTSUPP. As described in [0], such kfuncs can have their
arguments elided, which can cause BTF encoding to be skipped. The new
__bpf_kfunc macro should address this, and this patch adds a selftest
which verifies that a static kfunc with at least one unused argument can
still be encoded and invoked by a BPF program.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230201173016.342758-5-void@manifault.com
Now that we have the __bpf_kfunc tag, we should use add it to all
existing kfuncs to ensure that they'll never be elided in LTO builds.
Signed-off-by: David Vernet <void@manifault.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230201173016.342758-4-void@manifault.com
s390x ABI requires the caller to zero- or sign-extend the arguments.
eBPF already deals with zero-extension (by definition of its ABI), but
not with sign-extension.
Add a test to cover that potentially problematic area.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
Link: https://lore.kernel.org/r/20230128000650.1516334-15-iii@linux.ibm.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In a set of prior changes, we added the ability for struct_ops programs
to be sleepable. This patch enhances the dummy_st_ops selftest suite to
validate this behavior by adding a new sleepable struct_ops entry to
dummy_st_ops.
Signed-off-by: David Vernet <void@manifault.com>
Link: https://lore.kernel.org/r/20230125164735.785732-5-void@manifault.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Define a new kfunc set (xdp_metadata_kfunc_ids) which implements all possible
XDP metatada kfuncs. Not all devices have to implement them. If kfunc is not
supported by the target device, the default implementation is called instead.
The verifier, at load time, replaces a call to the generic kfunc with a call
to the per-device one. Per-device kfunc pointers are stored in separate
struct xdp_metadata_ops.
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Martin KaFai Lau <martin.lau@linux.dev>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Anatoly Burakov <anatoly.burakov@intel.com>
Cc: Alexander Lobakin <alexandr.lobakin@intel.com>
Cc: Magnus Karlsson <magnus.karlsson@gmail.com>
Cc: Maryam Tahhan <mtahhan@redhat.com>
Cc: xdp-hints@xdp-project.net
Cc: netdev@vger.kernel.org
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230119221536.3349901-8-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
* Randomize the per-cpu entry areas
Cleanups:
* Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open
coding it
* Move to "native" set_memory_rox() helper
* Clean up pmd_get_atomic() and i386-PAE
* Remove some unused page table size macros
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Merge tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 mm updates from Dave Hansen:
"New Feature:
- Randomize the per-cpu entry areas
Cleanups:
- Have CR3_ADDR_MASK use PHYSICAL_PAGE_MASK instead of open coding it
- Move to "native" set_memory_rox() helper
- Clean up pmd_get_atomic() and i386-PAE
- Remove some unused page table size macros"
* tag 'x86_mm_for_6.2_v2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (35 commits)
x86/mm: Ensure forced page table splitting
x86/kasan: Populate shadow for shared chunk of the CPU entry area
x86/kasan: Add helpers to align shadow addresses up and down
x86/kasan: Rename local CPU_ENTRY_AREA variables to shorten names
x86/mm: Populate KASAN shadow for entire per-CPU range of CPU entry area
x86/mm: Recompute physical address for every page of per-CPU CEA mapping
x86/mm: Rename __change_page_attr_set_clr(.checkalias)
x86/mm: Inhibit _PAGE_NX changes from cpa_process_alias()
x86/mm: Untangle __change_page_attr_set_clr(.checkalias)
x86/mm: Add a few comments
x86/mm: Fix CR3_ADDR_MASK
x86/mm: Remove P*D_PAGE_MASK and P*D_PAGE_SIZE macros
mm: Convert __HAVE_ARCH_P..P_GET to the new style
mm: Remove pointless barrier() after pmdp_get_lockless()
x86/mm/pae: Get rid of set_64bit()
x86_64: Remove pointless set_64bit() usage
x86/mm/pae: Be consistent with pXXp_get_and_clear()
x86/mm/pae: Use WRITE_ONCE()
x86/mm/pae: Don't (ab)use atomic64
mm/gup: Fix the lockless PMD access
...
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Alexei Starovoitov says:
====================
pull-request: bpf-next 2022-12-11
We've added 74 non-merge commits during the last 11 day(s) which contain
a total of 88 files changed, 3362 insertions(+), 789 deletions(-).
The main changes are:
1) Decouple prune and jump points handling in the verifier, from Andrii.
2) Do not rely on ALLOW_ERROR_INJECTION for fmod_ret, from Benjamin.
Merged from hid tree.
3) Do not zero-extend kfunc return values. Necessary fix for 32-bit archs,
from Björn.
4) Don't use rcu_users to refcount in task kfuncs, from David.
5) Three reg_state->id fixes in the verifier, from Eduard.
6) Optimize bpf_mem_alloc by reusing elements from free_by_rcu, from Hou.
7) Refactor dynptr handling in the verifier, from Kumar.
8) Remove the "/sys" mount and umount dance in {open,close}_netns
in bpf selftests, from Martin.
9) Enable sleepable support for cgrp local storage, from Yonghong.
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (74 commits)
selftests/bpf: test case for relaxed prunning of active_lock.id
selftests/bpf: Add pruning test case for bpf_spin_lock
bpf: use check_ids() for active_lock comparison
selftests/bpf: verify states_equal() maintains idmap across all frames
bpf: states_equal() must build idmap for all function frames
selftests/bpf: test cases for regsafe() bug skipping check_id()
bpf: regsafe() must not skip check_ids()
docs/bpf: Add documentation for BPF_MAP_TYPE_SK_STORAGE
selftests/bpf: Add test for dynptr reinit in user_ringbuf callback
bpf: Use memmove for bpf_dynptr_{read,write}
bpf: Move PTR_TO_STACK alignment check to process_dynptr_func
bpf: Rework check_func_arg_reg_off
bpf: Rework process_dynptr_func
bpf: Propagate errors from process_* checks in check_func_arg
bpf: Refactor ARG_PTR_TO_DYNPTR checks into process_dynptr_func
bpf: Skip rcu_barrier() if rcu_trace_implies_rcu_gp() is true
bpf: Reuse freed element in free_by_rcu during allocation
selftests/bpf: Bring test_offload.py back to life
bpf: Fix comment error in fixup_kfunc_call function
bpf: Do not zero-extend kfunc return values
...
====================
Link: https://lore.kernel.org/r/20221212024701.73809-1-alexei.starovoitov@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
syzkaller reported:
BUG: KASAN: slab-out-of-bounds in __build_skb_around+0x235/0x340 net/core/skbuff.c:294
Write of size 32 at addr ffff88802aa172c0 by task syz-executor413/5295
For bpf_prog_test_run_skb(), which uses a kmalloc()ed buffer passed to
build_skb().
When build_skb() is passed a frag_size of 0, it means the buffer came
from kmalloc. In these cases, ksize() is used to find its actual size,
but since the allocation may not have been made to that size, actually
perform the krealloc() call so that all the associated buffer size
checking will be correctly notified (and use the "new" pointer so that
compiler hinting works correctly). Split this logic out into a new
interface, slab_build_skb(), but leave the original 0 checking for now
to catch any stragglers.
Reported-by: syzbot+fda18eaa8c12534ccb3b@syzkaller.appspotmail.com
Link: https://groups.google.com/g/syzkaller-bugs/c/UnIKxTtU5-0/m/-wbXinkgAQAJ
Fixes: 38931d8989 ("mm: Make ksize() a reporting-only function")
Cc: Pavel Begunkov <asml.silence@gmail.com>
Cc: pepsipu <soopthegoop@gmail.com>
Cc: syzbot+fda18eaa8c12534ccb3b@syzkaller.appspotmail.com
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: kasan-dev <kasan-dev@googlegroups.com>
Cc: Andrii Nakryiko <andrii@kernel.org>
Cc: ast@kernel.org
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Hao Luo <haoluo@google.com>
Cc: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: John Fastabend <john.fastabend@gmail.com>
Cc: jolsa@kernel.org
Cc: KP Singh <kpsingh@kernel.org>
Cc: martin.lau@linux.dev
Cc: Stanislav Fomichev <sdf@google.com>
Cc: song@kernel.org
Cc: Yonghong Song <yhs@fb.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20221208060256.give.994-kees@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Merge "do not rely on ALLOW_ERROR_INJECTION for fmod_ret" into bpf-next
Merge commit 5b481acab4 ("bpf: do not rely on ALLOW_ERROR_INJECTION for fmod_ret")
from hid tree into bpf-next.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
The current way of expressing that a non-bpf kernel component is willing
to accept that bpf programs can be attached to it and that they can change
the return value is to abuse ALLOW_ERROR_INJECTION.
This is debated in the link below, and the result is that it is not a
reasonable thing to do.
Reuse the kfunc declaration structure to also tag the kernel functions
we want to be fmodret. This way we can control from any subsystem which
functions are being modified by bpf without touching the verifier.
Link: https://lore.kernel.org/all/20221121104403.1545f9b5@gandalf.local.home/
Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20221206145936.922196-2-benjamin.tissoires@redhat.com
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Daniel Borkmann says:
====================
bpf-next 2022-11-25
We've added 101 non-merge commits during the last 11 day(s) which contain
a total of 109 files changed, 8827 insertions(+), 1129 deletions(-).
The main changes are:
1) Support for user defined BPF objects: the use case is to allocate own
objects, build own object hierarchies and use the building blocks to
build own data structures flexibly, for example, linked lists in BPF,
from Kumar Kartikeya Dwivedi.
2) Add bpf_rcu_read_{,un}lock() support for sleepable programs,
from Yonghong Song.
3) Add support storing struct task_struct objects as kptrs in maps,
from David Vernet.
4) Batch of BPF map documentation improvements, from Maryam Tahhan
and Donald Hunter.
5) Improve BPF verifier to propagate nullness information for branches
of register to register comparisons, from Eduard Zingerman.
6) Fix cgroup BPF iter infra to hold reference on the start cgroup,
from Hou Tao.
7) Fix BPF verifier to not mark fentry/fexit program arguments as trusted
given it is not the case for them, from Alexei Starovoitov.
8) Improve BPF verifier's realloc handling to better play along with dynamic
runtime analysis tools like KASAN and friends, from Kees Cook.
9) Remove legacy libbpf mode support from bpftool,
from Sahid Orentino Ferdjaoui.
10) Rework zero-len skb redirection checks to avoid potentially breaking
existing BPF test infra users, from Stanislav Fomichev.
11) Two small refactorings which are independent and have been split out
of the XDP queueing RFC series, from Toke Høiland-Jørgensen.
12) Fix a memory leak in LSM cgroup BPF selftest, from Wang Yufen.
13) Documentation on how to run BPF CI without patch submission,
from Daniel Müller.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
====================
Link: https://lore.kernel.org/r/20221125012450.441-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
To avoid potentially breaking existing users.
Both mac/no-mac cases have to be amended; mac_header >= network_header
is not enough (verified with a new test, see next patch).
Fixes: fd18942244 ("bpf: Don't redirect packets with invalid pkt_len")
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20221121180340.1983627-1-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Instead of having to pass multiple arguments that describe the register,
pass the bpf_reg_state into the btf_struct_access callback. Currently,
all call sites simply reuse the btf and btf_id of the reg they want to
check the access of. The only exception to this pattern is the callsite
in check_ptr_to_map_access, hence for that case create a dummy reg to
simulate PTR_TO_BTF_ID access.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20221114191547.1694267-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We got a syzkaller problem because of aarch64 alignment fault
if KFENCE enabled. When the size from user bpf program is an odd
number, like 399, 407, etc, it will cause the struct skb_shared_info's
unaligned access. As seen below:
BUG: KFENCE: use-after-free read in __skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032
Use-after-free read at 0xffff6254fffac077 (in kfence-#213):
__lse_atomic_add arch/arm64/include/asm/atomic_lse.h:26 [inline]
arch_atomic_add arch/arm64/include/asm/atomic.h:28 [inline]
arch_atomic_inc include/linux/atomic-arch-fallback.h:270 [inline]
atomic_inc include/asm-generic/atomic-instrumented.h:241 [inline]
__skb_clone+0x23c/0x2a0 net/core/skbuff.c:1032
skb_clone+0xf4/0x214 net/core/skbuff.c:1481
____bpf_clone_redirect net/core/filter.c:2433 [inline]
bpf_clone_redirect+0x78/0x1c0 net/core/filter.c:2420
bpf_prog_d3839dd9068ceb51+0x80/0x330
bpf_dispatcher_nop_func include/linux/bpf.h:728 [inline]
bpf_test_run+0x3c0/0x6c0 net/bpf/test_run.c:53
bpf_prog_test_run_skb+0x638/0xa7c net/bpf/test_run.c:594
bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline]
__do_sys_bpf kernel/bpf/syscall.c:4441 [inline]
__se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381
kfence-#213: 0xffff6254fffac000-0xffff6254fffac196, size=407, cache=kmalloc-512
allocated by task 15074 on cpu 0 at 1342.585390s:
kmalloc include/linux/slab.h:568 [inline]
kzalloc include/linux/slab.h:675 [inline]
bpf_test_init.isra.0+0xac/0x290 net/bpf/test_run.c:191
bpf_prog_test_run_skb+0x11c/0xa7c net/bpf/test_run.c:512
bpf_prog_test_run kernel/bpf/syscall.c:3148 [inline]
__do_sys_bpf kernel/bpf/syscall.c:4441 [inline]
__se_sys_bpf+0xad0/0x1634 kernel/bpf/syscall.c:4381
__arm64_sys_bpf+0x50/0x60 kernel/bpf/syscall.c:4381
To fix the problem, we adjust @size so that (@size + @hearoom) is a
multiple of SMP_CACHE_BYTES. So we make sure the struct skb_shared_info
is aligned to a cache line.
Fixes: 1cf1cae963 ("bpf: introduce BPF_PROG_TEST_RUN command")
Signed-off-by: Baisong Zhong <zhongbaisong@huawei.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/bpf/20221102081620.1465154-1-zhongbaisong@huawei.com
We add 2 new kfuncs that are following the RET_PTR_TO_MEM
capability from the previous commit.
Then we test them in selftests:
the first tests are testing valid case, and are not failing,
and the later ones are actually preventing the program to be loaded
because they are wrong.
To work around that, we mark the failing ones as not autoloaded
(with SEC("?tc")), and we manually enable them one by one, ensuring
the verifier rejects them.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220906151303.2780789-8-benjamin.tissoires@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
We need to also export the kfunc set to the syscall program type,
and then add a couple of eBPF programs that are testing those calls.
The first one checks for valid access, and the second one is OK
from a static analysis point of view but fails at run time because
we are trying to access outside of the allocated memory.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220906151303.2780789-5-benjamin.tissoires@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Andrii Nakryiko says:
====================
bpf-next 2022-08-17
We've added 45 non-merge commits during the last 14 day(s) which contain
a total of 61 files changed, 986 insertions(+), 372 deletions(-).
The main changes are:
1) New bpf_ktime_get_tai_ns() BPF helper to access CLOCK_TAI, from Kurt
Kanzenbach and Jesper Dangaard Brouer.
2) Few clean ups and improvements for libbpf 1.0, from Andrii Nakryiko.
3) Expose crash_kexec() as kfunc for BPF programs, from Artem Savkov.
4) Add ability to define sleepable-only kfuncs, from Benjamin Tissoires.
5) Teach libbpf's bpf_prog_load() and bpf_map_create() to gracefully handle
unsupported names on old kernels, from Hangbin Liu.
6) Allow opting out from auto-attaching BPF programs by libbpf's BPF skeleton,
from Hao Luo.
7) Relax libbpf's requirement for shared libs to be marked executable, from
Henqgi Chen.
8) Improve bpf_iter internals handling of error returns, from Hao Luo.
9) Few accommodations in libbpf to support GCC-BPF quirks, from James Hilliard.
10) Fix BPF verifier logic around tracking dynptr ref_obj_id, from Joanne Koong.
11) bpftool improvements to handle full BPF program names better, from Manu
Bretelle.
12) bpftool fixes around libcap use, from Quentin Monnet.
13) BPF map internals clean ups and improvements around memory allocations,
from Yafang Shao.
14) Allow to use cgroup_get_from_file() on cgroupv1, allowing BPF cgroup
iterator to work on cgroupv1, from Yosry Ahmed.
15) BPF verifier internal clean ups, from Dave Marchevsky and Joanne Koong.
16) Various fixes and clean ups for selftests/bpf and vmtest.sh, from Daniel
Xu, Artem Savkov, Joanne Koong, Andrii Nakryiko, Shibin Koikkara Reeny.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (45 commits)
selftests/bpf: Few fixes for selftests/bpf built in release mode
libbpf: Clean up deprecated and legacy aliases
libbpf: Streamline bpf_attr and perf_event_attr initialization
libbpf: Fix potential NULL dereference when parsing ELF
selftests/bpf: Tests libbpf autoattach APIs
libbpf: Allows disabling auto attach
selftests/bpf: Fix attach point for non-x86 arches in test_progs/lsm
libbpf: Making bpf_prog_load() ignore name if kernel doesn't support
selftests/bpf: Update CI kconfig
selftests/bpf: Add connmark read test
selftests/bpf: Add existing connection bpf_*_ct_lookup() test
bpftool: Clear errno after libcap's checks
bpf: Clear up confusion in bpf_skb_adjust_room()'s documentation
bpftool: Fix a typo in a comment
libbpf: Add names for auxiliary maps
bpf: Use bpf_map_area_alloc consistently on bpf map creation
bpf: Make __GFP_NOWARN consistent in bpf map creation
bpf: Use bpf_map_area_free instread of kvfree
bpf: Remove unneeded memset in queue_stack_map creation
libbpf: preserve errno across pr_warn/pr_info/pr_debug
...
====================
Link: https://lore.kernel.org/r/20220817215656.1180215-1-andrii@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a test checking that programs calling destructive kfuncs can only do
so if they have CAP_SYS_BOOT capabilities.
Signed-off-by: Artem Savkov <asavkov@redhat.com>
Link: https://lore.kernel.org/r/20220810065905.475418-4-asavkov@redhat.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
In addition to TC hook, enable these in tracing programs so that they
can be used in selftests.
Acked-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220809213033.24147-2-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Teach the verifier to detect a new KF_TRUSTED_ARGS kfunc flag, which
means each pointer argument must be trusted, which we define as a
pointer that is referenced (has non-zero ref_obj_id) and also needs to
have its offset unchanged, similar to how release functions expect their
argument. This allows a kfunc to receive pointer arguments unchanged
from the result of the acquire kfunc.
This is required to ensure that kfunc that operate on some object only
work on acquired pointers and not normal PTR_TO_BTF_ID with same type
which can be obtained by pointer walking. The restrictions applied to
release arguments also apply to trusted arguments. This implies that
strict type matching (not deducing type by recursively following members
at offset) and OBJ_RELEASE offset checks (ensuring they are zero) are
used for trusted pointer arguments.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-5-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Instead of populating multiple sets to indicate some attribute and then
researching the same BTF ID in them, prepare a single unified BTF set
which indicates whether a kfunc is allowed to be called, and also its
attributes if any at the same time. Now, only one call is needed to
perform the lookup for both kfunc availability and its attributes.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-4-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
These checks were effectively noops b/c there's only one way these
functions get called: through prog_ops dispatching. And since there's no
other callers, we can be sure that `prog` is always the correct type.
Signed-off-by: Daniel Xu <dxu@dxuuu.xyz>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/0a9aaac329f76ddb17df1786b001117823ffefa5.1653855302.git.dxu@dxuuu.xyz
Yonghong Song