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>
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>
Daniel Borkmann says:
====================
pull-request: bpf-next 2022-05-23
We've added 113 non-merge commits during the last 26 day(s) which contain
a total of 121 files changed, 7425 insertions(+), 1586 deletions(-).
The main changes are:
1) Speed up symbol resolution for kprobes multi-link attachments, from Jiri Olsa.
2) Add BPF dynamic pointer infrastructure e.g. to allow for dynamically sized ringbuf
reservations without extra memory copies, from Joanne Koong.
3) Big batch of libbpf improvements towards libbpf 1.0 release, from Andrii Nakryiko.
4) Add BPF link iterator to traverse links via seq_file ops, from Dmitrii Dolgov.
5) Add source IP address to BPF tunnel key infrastructure, from Kaixi Fan.
6) Refine unprivileged BPF to disable only object-creating commands, from Alan Maguire.
7) Fix JIT blinding of ld_imm64 when they point to subprogs, from Alexei Starovoitov.
8) Add BPF access to mptcp_sock structures and their meta data, from Geliang Tang.
9) Add new BPF helper for access to remote CPU's BPF map elements, from Feng Zhou.
10) Allow attaching 64-bit cookie to BPF link of fentry/fexit/fmod_ret, from Kui-Feng Lee.
11) Follow-ups to typed pointer support in BPF maps, from Kumar Kartikeya Dwivedi.
12) Add busy-poll test cases to the XSK selftest suite, from Magnus Karlsson.
13) Improvements in BPF selftest test_progs subtest output, from Mykola Lysenko.
14) Fill bpf_prog_pack allocator areas with illegal instructions, from Song Liu.
15) Add generic batch operations for BPF map-in-map cases, from Takshak Chahande.
16) Make bpf_jit_enable more user friendly when permanently on 1, from Tiezhu Yang.
17) Fix an array overflow in bpf_trampoline_get_progs(), from Yuntao Wang.
====================
Link: https://lore.kernel.org/r/20220523223805.27931-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The code for gso_max_size was added originally to allow for debugging and
workaround of buggy devices that couldn't support TSO with blocks 64K in
size. The original reason for limiting it to 64K was because that was the
existing limits of IPv4 and non-jumbogram IPv6 length fields.
With the addition of Big TCP we can remove this limit and allow the value
to potentially go up to UINT_MAX and instead be limited by the tso_max_size
value.
So in order to support this we need to go through and clean up the
remaining users of the gso_max_size value so that the values will cap at
64K for non-TCPv6 flows. In addition we can clean up the GSO_MAX_SIZE value
so that 64K becomes GSO_LEGACY_MAX_SIZE and UINT_MAX will now be the upper
limit for GSO_MAX_SIZE.
v6: (edumazet) fixed a compile error if CONFIG_IPV6=n,
in a new sk_trim_gso_size() helper.
netif_set_tso_max_size() caps the requested TSO size
with GSO_MAX_SIZE.
Signed-off-by: Alexander Duyck <alexanderduyck@fb.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In an effort to actually test the refcounting logic at runtime, add a
refcount_t member to prog_test_ref_kfunc and use it in selftests to
verify and test the whole logic more exhaustively.
The kfunc calls for prog_test_member do not require runtime refcounting,
as they are only used for verifier selftests, not during runtime
execution. Hence, their implementation now has a WARN_ON_ONCE as it is
not meant to be reachable code at runtime. It is strictly used in tests
triggering failure cases in the verifier. bpf_kfunc_call_memb_release is
called from map free path, since prog_test_member is embedded in map
value for some verifier tests, so we skip WARN_ON_ONCE for it.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220511194654.765705-3-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Replace struct bpf_tramp_progs with struct bpf_tramp_links to collect
struct bpf_tramp_link(s) for a trampoline. struct bpf_tramp_link
extends bpf_link to act as a linked list node.
arch_prepare_bpf_trampoline() accepts a struct bpf_tramp_links to
collects all bpf_tramp_link(s) that a trampoline should call.
Change BPF trampoline and bpf_struct_ops to pass bpf_tramp_links
instead of bpf_tramp_progs.
Signed-off-by: Kui-Feng Lee <kuifeng@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20220510205923.3206889-2-kuifeng@fb.com
The live packet mode in BPF_PROG_RUN allocates a page_pool instance for
each test run instance and uses it for the packet data. On setup it creates
the page_pool, and calls xdp_reg_mem_model() to allow pages to be returned
properly from the XDP data path. However, xdp_reg_mem_model() also raises
the reference count of the page_pool itself, so the single
page_pool_destroy() count on teardown was not enough to actually release
the pool. To fix this, add an additional xdp_unreg_mem_model() call on
teardown.
Fixes: b530e9e106 ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Reported-by: Freysteinn Alfredsson <freysteinn.alfredsson@kau.se>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Song Liu <songliubraving@fb.com>
Link: https://lore.kernel.org/bpf/20220409213053.3117305-1-toke@redhat.com
The live packet mode uses some extra space at the start of each page to
cache data structures so they don't have to be rebuilt at every repetition.
This space wasn't correctly accounted for in the size checking of the
arguments supplied to userspace. In addition, the definition of the frame
size should include the size of the skb_shared_info (as there is other
logic that subtracts the size of this).
Together, these mistakes resulted in userspace being able to trip the
XDP_WARN() in xdp_update_frame_from_buff(), which syzbot discovered in
short order. Fix this by changing the frame size define and adding the
extra headroom to the bpf_prog_test_run_xdp() function. Also drop the
max_len parameter to the page_pool init, since this is related to DMA which
is not used for the page pool instance in PROG_TEST_RUN.
Fixes: b530e9e106 ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Reported-by: syzbot+0e91362d99386dc5de99@syzkaller.appspotmail.com
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220310225621.53374-1-toke@redhat.com
The kernel test robot pointed out that the newly added
bpf_test_run_xdp_live() runner doesn't set the retval in the caller (by
design), which means that the variable can be passed unitialised to
bpf_test_finish(). Fix this by initialising the variable properly.
Fixes: b530e9e106 ("bpf: Add "live packet" mode for XDP in BPF_PROG_RUN")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20220310110228.161869-1-toke@redhat.com
This adds support for running XDP programs through BPF_PROG_RUN in a mode
that enables live packet processing of the resulting frames. Previous uses
of BPF_PROG_RUN for XDP returned the XDP program return code and the
modified packet data to userspace, which is useful for unit testing of XDP
programs.
The existing BPF_PROG_RUN for XDP allows userspace to set the ingress
ifindex and RXQ number as part of the context object being passed to the
kernel. This patch reuses that code, but adds a new mode with different
semantics, which can be selected with the new BPF_F_TEST_XDP_LIVE_FRAMES
flag.
When running BPF_PROG_RUN in this mode, the XDP program return codes will
be honoured: returning XDP_PASS will result in the frame being injected
into the networking stack as if it came from the selected networking
interface, while returning XDP_TX and XDP_REDIRECT will result in the frame
being transmitted out that interface. XDP_TX is translated into an
XDP_REDIRECT operation to the same interface, since the real XDP_TX action
is only possible from within the network drivers themselves, not from the
process context where BPF_PROG_RUN is executed.
Internally, this new mode of operation creates a page pool instance while
setting up the test run, and feeds pages from that into the XDP program.
The setup cost of this is amortised over the number of repetitions
specified by userspace.
To support the performance testing use case, we further optimise the setup
step so that all pages in the pool are pre-initialised with the packet
data, and pre-computed context and xdp_frame objects stored at the start of
each page. This makes it possible to entirely avoid touching the page
content on each XDP program invocation, and enables sending up to 9
Mpps/core on my test box.
Because the data pages are recycled by the page pool, and the test runner
doesn't re-initialise them for each run, subsequent invocations of the XDP
program will see the packet data in the state it was after the last time it
ran on that particular page. This means that an XDP program that modifies
the packet before redirecting it has to be careful about which assumptions
it makes about the packet content, but that is only an issue for the most
naively written programs.
Enabling the new flag is only allowed when not setting ctx_out and data_out
in the test specification, since using it means frames will be redirected
somewhere else, so they can't be returned.
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/bpf/20220309105346.100053-2-toke@redhat.com
Include a few verifier selftests that test against the problems being
fixed by previous commits, i.e. release kfunc always require
PTR_TO_BTF_ID fixed and var_off to be 0, and negative offset is not
permitted and returns a helpful error message.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220304224645.3677453-9-memxor@gmail.com
Currently, -Wmissing-prototypes warning is ignored for GCC, but not
clang. This leads to clang build warning in W=1 mode. Since the flag
used by both compilers is same, we can use the unified __diag_ignore_all
macro that works for all supported versions and compilers which have
__diag macro support (currently GCC >= 8.0, and Clang >= 11.0).
Also add nf_conntrack_bpf.h include to prevent missing prototype warning
for register_nf_conntrack_bpf.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220304224645.3677453-8-memxor@gmail.com
Syzkaller reports another issue:
WARNING: CPU: 0 PID: 10775 at include/linux/thread_info.h:230
check_copy_size include/linux/thread_info.h:230 [inline]
WARNING: CPU: 0 PID: 10775 at include/linux/thread_info.h:230
copy_to_user include/linux/uaccess.h:199 [inline]
WARNING: CPU: 0 PID: 10775 at include/linux/thread_info.h:230
bpf_test_finish.isra.0+0x4b2/0x680 net/bpf/test_run.c:171
This can happen when the userspace buffer is smaller than head + frags.
Return ENOSPC in this case.
Fixes: 7855e0db15 ("bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature")
Reported-by: syzbot+5f81df6205ecbbc56ab5@syzkaller.appspotmail.com
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Lorenzo Bianconi <lorenzo@kernel.org>
Link: https://lore.kernel.org/bpf/20220228232332.458871-1-sdf@google.com
remote_port is another case of a BPF context field documented as a 32-bit
value in network byte order for which the BPF context access converter
generates a load of a zero-padded 16-bit integer in network byte order.
First such case was dst_port in bpf_sock which got addressed in commit
4421a58271 ("bpf: Make dst_port field in struct bpf_sock 16-bit wide").
Loading 4-bytes from the remote_port offset and converting the value with
bpf_ntohl() leads to surprising results, as the expected value is shifted
by 16 bits.
Reduce the confusion by splitting the field in two - a 16-bit field holding
a big-endian integer, and a 16-bit zero-padding anonymous field that
follows it.
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220209184333.654927-2-jakub@cloudflare.com
