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Author SHA1 Message Date
Jakub Kicinski
75455b906d bpf-next-for-netdev
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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Daniel Borkmann says:

====================
pull-request: bpf-next 2023-05-26

We've added 54 non-merge commits during the last 10 day(s) which contain
a total of 76 files changed, 2729 insertions(+), 1003 deletions(-).

The main changes are:

1) Add the capability to destroy sockets in BPF through a new kfunc,
   from Aditi Ghag.

2) Support O_PATH fds in BPF_OBJ_PIN and BPF_OBJ_GET commands,
   from Andrii Nakryiko.

3) Add capability for libbpf to resize datasec maps when backed via mmap,
   from JP Kobryn.

4) Move all the test kfuncs for CI out of the kernel and into bpf_testmod,
   from Jiri Olsa.

5) Big batch of xsk selftest improvements to prep for multi-buffer testing,
   from Magnus Karlsson.

6) Show the target_{obj,btf}_id in tracing link's fdinfo and dump it
   via bpftool, from Yafang Shao.

7) Various misc BPF selftest improvements to work with upcoming LLVM 17,
   from Yonghong Song.

8) Extend bpftool to specify netdevice for resolving XDP hints,
   from Larysa Zaremba.

9) Document masking in shift operations for the insn set document,
   from Dave Thaler.

10) Extend BPF selftests to check xdp_feature support for bond driver,
    from Lorenzo Bianconi.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (54 commits)
  bpf: Fix bad unlock balance on freeze_mutex
  libbpf: Ensure FD >= 3 during bpf_map__reuse_fd()
  libbpf: Ensure libbpf always opens files with O_CLOEXEC
  selftests/bpf: Check whether to run selftest
  libbpf: Change var type in datasec resize func
  bpf: drop unnecessary bpf_capable() check in BPF_MAP_FREEZE command
  libbpf: Selftests for resizing datasec maps
  libbpf: Add capability for resizing datasec maps
  selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests
  libbpf: Add opts-based bpf_obj_pin() API and add support for path_fd
  bpf: Support O_PATH FDs in BPF_OBJ_PIN and BPF_OBJ_GET commands
  libbpf: Start v1.3 development cycle
  bpf: Validate BPF object in BPF_OBJ_PIN before calling LSM
  bpftool: Specify XDP Hints ifname when loading program
  selftests/bpf: Add xdp_feature selftest for bond device
  selftests/bpf: Test bpf_sock_destroy
  selftests/bpf: Add helper to get port using getsockname
  bpf: Add bpf_sock_destroy kfunc
  bpf: Add kfunc filter function to 'struct btf_kfunc_id_set'
  bpf: udp: Implement batching for sockets iterator
  ...
====================

Link: https://lore.kernel.org/r/20230526222747.17775-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-26 17:26:01 -07:00
Jakub Kicinski
d4031ec844 Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net
Cross-merge networking fixes after downstream PR.

Conflicts:

net/ipv4/raw.c
  3632679d9e ("ipv{4,6}/raw: fix output xfrm lookup wrt protocol")
  c85be08fc4 ("raw: Stop using RTO_ONLINK.")
https://lore.kernel.org/all/20230525110037.2b532b83@canb.auug.org.au/

Adjacent changes:

drivers/net/ethernet/freescale/fec_main.c
  9025944fdd ("net: fec: add dma_wmb to ensure correct descriptor values")
  144470c88c ("net: fec: using the standard return codes when xdp xmit errors")

Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2023-05-25 19:57:39 -07:00
Daniel Müller
321a64b328 selftests/bpf: Check whether to run selftest
The sockopt test invokes test__start_subtest and then unconditionally
asserts the success. That means that even if deny-listed, any test will
still run and potentially fail.
Evaluate the return value of test__start_subtest() to achieve the
desired behavior, as other tests do.

Signed-off-by: Daniel Müller <deso@posteo.net>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20230525232248.640465-1-deso@posteo.net
2023-05-25 16:51:05 -07:00
JP Kobryn
08b0895675 libbpf: Selftests for resizing datasec maps
This patch adds test coverage for resizing datasec maps. The first two
subtests resize the bss and custom data sections. In both cases, an
initial array (of length one) has its element set to one. After resizing
the rest of the array is filled with ones as well. A BPF program is then
run to sum the respective arrays and back on the userspace side the sum
is checked to be equal to the number of elements.
The third subtest attempts to perform resizing under conditions that
will result in either the resize failing or the BTF info being cleared.

Signed-off-by: JP Kobryn <inwardvessel@gmail.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/20230524004537.18614-3-inwardvessel@gmail.com
2023-05-24 11:44:17 -07:00
Andrii Nakryiko
3b22f98e5a selftests/bpf: Add path_fd-based BPF_OBJ_PIN and BPF_OBJ_GET tests
Add a selftest demonstrating using detach-mounted BPF FS using new mount
APIs, and pinning and getting BPF map using such mount. This
demonstrates how something like container manager could setup BPF FS,
pin and adjust all the necessary objects in it, all before exposing BPF
FS to a particular mount namespace.

Also add a few subtests validating all meaningful combinations of
path_fd and pathname. We use mounted /sys/fs/bpf location for these.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230523170013.728457-5-andrii@kernel.org
2023-05-23 23:41:07 +02:00
Lorenzo Bianconi
6cc385d2cd selftests/bpf: Add xdp_feature selftest for bond device
Introduce selftests to check xdp_feature support for bond driver.

Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jussi Maki <joamaki@gmail.com>
Link: https://lore.kernel.org/bpf/64cb8f20e6491f5b971f8d3129335093c359aad7.1684329998.git.lorenzo@kernel.org
2023-05-23 16:22:25 +02:00
John Fastabend
f726e03564 bpf, sockmap: Test progs verifier error with latest clang
With a relatively recent clang (7090c10273119) and with this commit
to fix warnings in selftests (c8ed668593) that uses __sink(err)
to resolve unused variables. We get the following verifier error.

root@6e731a24b33a:/host/tools/testing/selftests/bpf# ./test_sockmap
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0)          ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5        ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15       ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68)         ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --
libbpf: prog 'bpf_sockmap': failed to load: -13
libbpf: failed to load object 'test_sockmap_kern.bpf.o'
load_bpf_file: (-1) No such file or directory
ERROR: (-1) load bpf failed
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0)          ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5        ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15       ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68)         ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --
libbpf: prog 'bpf_sockmap': failed to load: -13
libbpf: failed to load object 'test_sockhash_kern.bpf.o'
load_bpf_file: (-1) No such file or directory
ERROR: (-1) load bpf failed
libbpf: prog 'bpf_sockmap': BPF program load failed: Permission denied
libbpf: prog 'bpf_sockmap': -- BEGIN PROG LOAD LOG --
0: R1=ctx(off=0,imm=0) R10=fp0
; op = (int) skops->op;
0: (61) r2 = *(u32 *)(r1 +0)          ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; switch (op) {
1: (16) if w2 == 0x4 goto pc+5        ; R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
2: (56) if w2 != 0x5 goto pc+15       ; R2_w=5
; lport = skops->local_port;
3: (61) r2 = *(u32 *)(r1 +68)         ; R1=ctx(off=0,imm=0) R2_w=scalar(umax=4294967295,var_off=(0x0; 0xffffffff))
; if (lport == 10000) {
4: (56) if w2 != 0x2710 goto pc+13 18: R1=ctx(off=0,imm=0) R2=scalar(umax=4294967295,var_off=(0x0; 0xffffffff)) R10=fp0
; __sink(err);
18: (bc) w1 = w0
R0 !read_ok
processed 18 insns (limit 1000000) max_states_per_insn 0 total_states 2 peak_states 2 mark_read 1
-- END PROG LOAD LOG --

To fix simply remove the err value because its not actually used anywhere
in the testing. We can investigate the root cause later. Future patch should
probably actually test the err value as well. Although if the map updates
fail they will get caught eventually by userspace.

Fixes: c8ed668593 ("selftests/bpf: fix lots of silly mistakes pointed out by compiler")
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-15-john.fastabend@gmail.com
2023-05-23 16:11:27 +02:00
John Fastabend
80e24d2226 bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer with drops
When BPF program drops pkts the sockmap logic 'eats' the packet and
updates copied_seq. In the PASS case where the sk_buff is accepted
we update copied_seq from recvmsg path so we need a new test to
handle the drop case.

Original patch series broke this resulting in

test_sockmap_skb_verdict_fionread:PASS:ioctl(FIONREAD) error 0 nsec
test_sockmap_skb_verdict_fionread:FAIL:ioctl(FIONREAD) unexpected ioctl(FIONREAD): actual 1503041772 != expected 256

After updated patch with fix.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-14-john.fastabend@gmail.com
2023-05-23 16:11:20 +02:00
John Fastabend
bb516f98c7 bpf, sockmap: Test FIONREAD returns correct bytes in rx buffer
A bug was reported where ioctl(FIONREAD) returned zero even though the
socket with a SK_SKB verdict program attached had bytes in the msg
queue. The result is programs may hang or more likely try to recover,
but use suboptimal buffer sizes.

Add a test to check that ioctl(FIONREAD) returns the correct number of
bytes.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-13-john.fastabend@gmail.com
2023-05-23 16:11:13 +02:00
John Fastabend
1fa1fe8ff1 bpf, sockmap: Test shutdown() correctly exits epoll and recv()=0
When session gracefully shutdowns epoll needs to wake up and any recv()
readers should return 0 not the -EAGAIN they previously returned.

Note we use epoll instead of select to test the epoll wake on shutdown
event as well.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-12-john.fastabend@gmail.com
2023-05-23 16:11:05 +02:00
John Fastabend
298970c8af bpf, sockmap: Build helper to create connected socket pair
A common operation for testing is to spin up a pair of sockets that are
connected. Then we can use these to run specific tests that need to
send data, check BPF programs and so on.

The sockmap_listen programs already have this logic lets move it into
the new sockmap_helpers header file for general use.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-11-john.fastabend@gmail.com
2023-05-23 16:10:58 +02:00
John Fastabend
4e02588d9a bpf, sockmap: Pull socket helpers out of listen test for general use
No functional change here we merely pull the helpers in sockmap_listen.c
into a header file so we can use these in other programs. The tests we
are about to add aren't really _listen tests so doesn't make sense
to add them here.

Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Link: https://lore.kernel.org/bpf/20230523025618.113937-10-john.fastabend@gmail.com
2023-05-23 16:10:50 +02:00
Aditi Ghag
1a8bc2299f selftests/bpf: Test bpf_sock_destroy
The test cases for destroying sockets mirror the intended usages of the
bpf_sock_destroy kfunc using iterators.

The destroy helpers set `ECONNABORTED` error code that we can validate
in the test code with client sockets. But UDP sockets have an overriding
error code from `disconnect()` called during abort, so the error code
validation is only done for TCP sockets.

The failure test cases validate that the `bpf_sock_destroy` kfunc is not
allowed from program attach types other than BPF trace iterator, and
such programs fail to load.

Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com>
Link: https://lore.kernel.org/r/20230519225157.760788-10-aditi.ghag@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-19 22:44:28 -07:00
Aditi Ghag
176ba657e6 selftests/bpf: Add helper to get port using getsockname
The helper will be used to programmatically retrieve
and pass ports in userspace and kernel selftest programs.

Suggested-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Aditi Ghag <aditi.ghag@isovalent.com>
Link: https://lore.kernel.org/r/20230519225157.760788-9-aditi.ghag@isovalent.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-19 22:44:28 -07:00
Yonghong Song
effcf62416 selftests/bpf: Make bpf_dynptr_is_rdonly() prototyype consistent with kernel
Currently kernel kfunc bpf_dynptr_is_rdonly() has prototype ...

  __bpf_kfunc bool bpf_dynptr_is_rdonly(struct bpf_dynptr_kern *ptr)

... while selftests bpf_kfuncs.h has:

  extern int bpf_dynptr_is_rdonly(const struct bpf_dynptr *ptr) __ksym;

Such a mismatch might cause problems although currently it is okay in
selftests. Fix it to prevent future potential surprise.

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230517040409.4024618-1-yhs@fb.com
2023-05-17 16:54:50 +02:00
Yonghong Song
12852f8e0f selftests/bpf: Fix dynptr/test_dynptr_is_null
With latest llvm17, dynptr/test_dynptr_is_null subtest failed in my testing
VM. The failure log looks like below:

  All error logs:
  tester_init:PASS:tester_log_buf 0 nsec
  process_subtest:PASS:obj_open_mem 0 nsec
  process_subtest:PASS:Can't alloc specs array 0 nsec
  verify_success:PASS:dynptr_success__open 0 nsec
  verify_success:PASS:bpf_object__find_program_by_name 0 nsec
  verify_success:PASS:dynptr_success__load 0 nsec
  verify_success:PASS:bpf_program__attach 0 nsec
  verify_success:FAIL:err unexpected err: actual 4 != expected 0
  #65/9    dynptr/test_dynptr_is_null:FAIL

The error happens for bpf prog test_dynptr_is_null in dynptr_success.c:

        if (bpf_dynptr_is_null(&ptr2)) {
                err = 4;
                goto exit;
        }

The bpf_dynptr_is_null(&ptr) unexpectedly returned a non-zero value and
the control went to the error path. Digging further, I found the root cause
is due to function signature difference between kernel and user space.

In kernel, we have ...

  __bpf_kfunc bool bpf_dynptr_is_null(struct bpf_dynptr_kern *ptr)

... while in bpf_kfuncs.h we have:

  extern int bpf_dynptr_is_null(const struct bpf_dynptr *ptr) __ksym;

The kernel bpf_dynptr_is_null disasm code:

  ffffffff812f1a90 <bpf_dynptr_is_null>:
  ffffffff812f1a90: f3 0f 1e fa           endbr64
  ffffffff812f1a94: 0f 1f 44 00 00        nopl    (%rax,%rax)
  ffffffff812f1a99: 53                    pushq   %rbx
  ffffffff812f1a9a: 48 89 fb              movq    %rdi, %rbx
  ffffffff812f1a9d: e8 ae 29 17 00        callq   0xffffffff81464450 <__asan_load8_noabort>
  ffffffff812f1aa2: 48 83 3b 00           cmpq    $0x0, (%rbx)
  ffffffff812f1aa6: 0f 94 c0              sete    %al
  ffffffff812f1aa9: 5b                    popq    %rbx
  ffffffff812f1aaa: c3                    retq

Note that only 1-byte register %al is set and the other 7-bytes are not
touched. In bpf program, the asm code for the above bpf_dynptr_is_null(&ptr2):

       266:       85 10 00 00 ff ff ff ff call -0x1
       267:       b4 01 00 00 04 00 00 00 w1 = 0x4
       268:       16 00 03 00 00 00 00 00 if w0 == 0x0 goto +0x3 <LBB9_8>

Basically, 4-byte subregister is tested. This might cause error as the value
other than the lowest byte might not be 0.

This patch fixed the issue by using the identical func prototype across kernel
and selftest user space. The fixed bpf asm code:

       267:       85 10 00 00 ff ff ff ff call -0x1
       268:       54 00 00 00 01 00 00 00 w0 &= 0x1
       269:       b4 01 00 00 04 00 00 00 w1 = 0x4
       270:       16 00 03 00 00 00 00 00 if w0 == 0x0 goto +0x3 <LBB9_8>

Signed-off-by: Yonghong Song <yhs@fb.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://lore.kernel.org/bpf/20230517040404.4023912-1-yhs@fb.com
2023-05-17 16:52:26 +02:00
Alexey Gladkov
f04a32b2c5 selftests/bpf: Do not use sign-file as testcase
The sign-file utility (from scripts/) is used in prog_tests/verify_pkcs7_sig.c,
but the utility should not be called as a test. Executing this utility produces
the following error:

  selftests: /linux/tools/testing/selftests/bpf: urandom_read
  ok 16 selftests: /linux/tools/testing/selftests/bpf: urandom_read

  selftests: /linux/tools/testing/selftests/bpf: sign-file
  not ok 17 selftests: /linux/tools/testing/selftests/bpf: sign-file # exit=2

Also, urandom_read is mistakenly used as a test. It does not lead to an error,
but should be moved over to TEST_GEN_FILES as well. The empty TEST_CUSTOM_PROGS
can then be removed.

Fixes: fc97590668 ("selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc")
Signed-off-by: Alexey Gladkov <legion@kernel.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/bpf/ZEuWFk3QyML9y5QQ@example.org
Link: https://lore.kernel.org/bpf/88e3ab23029d726a2703adcf6af8356f7a2d3483.1684316821.git.legion@kernel.org
2023-05-17 15:43:32 +02:00
Magnus Karlsson
7cd6df4f5e selftests/xsk: adjust packet pacing for multi-buffer support
Modify the packet pacing algorithm so that it works with multi-buffer
packets. This algorithm makes sure we do not send too many buffers to
the receiving thread so that packets have to be dropped. The previous
algorithm made the assumption that each packet only consumes one
buffer, but that is not true anymore when multi-buffer support gets
added. Instead, we find out what the largest packet size is in the
packet stream and assume that each packet will consume this many
buffers. This is conservative and overly cautious as there might be
smaller packets in the stream that need fewer buffers per packet. But
it keeps the algorithm simple.

Also simplify it by removing the pthread conditional and just test if
there is enough space in the Rx thread before trying to send one more
batch. Also makes the tests run faster.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-11-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:52 -07:00
Magnus Karlsson
2f6eae0df1 selftests/xsk: generate data for multi-buffer packets
Add the ability to generate data in the packets that are correct for
multi-buffer packets. The ethernet header should only go into the
first fragment followed by data and the others should only have
data. We also need to modify the pkt_dump function so that it knows
what fragment has an ethernet header so it can print this.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-10-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
86e41755b4 selftests/xsk: populate fill ring based on frags needed
Populate the fill ring based on the number of frags a packet
needs. With multi-buffer support, a packet might require more than a
single fragment/buffer, so the function xsk_populate_fill_ring() needs
to consider how many buffers a packet will consume, and put that many
buffers on the fill ring for each packet it should receive. As we are
still not sending any multi-buffer packets, the function will only
produce one buffer per packet at the moment.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-9-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
041b68f688 selftests/xsx: test for huge pages only once
Test for hugepages only once at the beginning of the execution of the
whole test suite, instead of before each test that needs huge
pages. These are the tests that use unaligned mode. As more unaligned
tests will be added, so the current system just does not scale.

With this change, there are now three possible outcomes of a test run:
fail, pass, or skip. To simplify the handling of this, the function
testapp_validate_traffic() now returns this value to the main loop. As
this function is used by nearly all tests, it meant a small change to
most of them.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-8-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
d9f6d9709f selftests/xsk: store offset in pkt instead of addr
Store the offset in struct pkt instead of the address. This is
important since address is only meaningful in the context of a packet
that is stored in a single umem buffer and thus a single Tx
descriptor. If the packet, in contrast need to be represented by
multiple buffers in the umem, storing the address makes no sense since
the packet will consist of multiple buffers in the umem at various
addresses. This change is in preparation for the upcoming
multi-buffer support in AF_XDP and the corresponding tests.

So instead of indicating the address, we instead indicate the offset
of the packet in the first buffer. The actual address of the buffer is
allocated from the umem with a new function called
umem_alloc_buffer(). This also means we can get rid of the
use_fill_for_addr flag as the addresses fed into the fill ring will
always be the offset from the pkt specification in the packet stream
plus the address of the allocated buffer from the umem. No special
casing needed.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-7-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
69fc03d220 selftests/xsk: add packet iterator for tx to packet stream
Convert the current variable rx_pkt_nb to an iterator that can be used
for both Rx and Tx. This to simplify the code and making Tx more like
Rx that already has this feature.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-6-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
7a8a676282 selftests/xsk: dump packet at error
Dump the content of the packet when a test finds that packets are
received out of order, the length is wrong, or some other packet
error. Use the already existing pkt_dump function for this and call it
when the above errors are detected. Get rid of the command line option
for dumping packets as it is not useful to print out thousands of
good packets followed by the faulty one you would like to see.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-5-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
feb973a909 selftests/xsk: add varying payload pattern within packet
Add a varying payload pattern within the packet. Instead of having
just a packet number that is the same for all words in a packet, make
each word different in the packet. The upper 16-bits are set to the
packet number and the lower 16-bits are the sequence number of the
words in this packet. So the 3rd packet's 5th 32-bit word of data will
contain the number (2<<32) | 4 as they are numbered from 0.

This will make it easier to detect fragments that are out of order
when starting to test multi-buffer support.

The member payload in the packet is renamed pkt_nb to reflect that it
is now only a pkt_nb, not the real payload as seen above.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-4-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
df82d2e89c selftests/xsk: generate simpler packets with variable length
Implement support for generating pkts with variable length. Before
this patch, they were all 64 bytes, exception for some packets of zero
length and some that were too large. This feature will be used to test
multi-buffer support for which large packets are needed.

The packets are also made simpler, just a valid Ethernet header
followed by a sequence number. This so that it will become easier to
implement packet generation when each packet consists of multiple
fragments. There is also a maintenance burden associated with carrying
all this code for generating proper UDP/IP packets, especially since
they are not needed.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-3-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Magnus Karlsson
d2e5414949 selftests/xsk: do not change XDP program when not necessary
Do not change the XDP program for the Tx thread when not needed. It
was erroneously compared to the XDP program for the Rx thread, which
is always going to be different, which meant that the code made
unnecessary switches to the same program it had before. This did not
affect functionality, just performance.

Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230516103109.3066-2-magnus.karlsson@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:31:51 -07:00
Jiri Olsa
65eb006d85 bpf: Move kernel test kfuncs to bpf_testmod
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>
2023-05-16 22:09:24 -07:00
Jiri Olsa
6e2b50fa81 selftests/bpf: Remove extern from kfuncs declarations
There's no need to keep the extern in kfuncs declarations.

Suggested-by: David Vernet <void@manifault.com>
Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-10-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
f26ebdd3e4 selftests/bpf: Allow to use kfunc from testmod.ko in test_verifier
Currently the test_verifier allows test to specify kfunc symbol
and search for it in the kernel BTF.

Adding the possibility to search for kfunc also in bpf_testmod
module when it's not found in kernel BTF.

To find bpf_testmod btf we need to get back SYS_ADMIN cap.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-9-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
b23b385fa1 selftests/bpf: Load bpf_testmod for verifier test
Loading bpf_testmod kernel module for verifier test. We will
move all the tests kfuncs into bpf_testmod in following change.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-8-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
11642eb92b selftests/bpf: Use un/load_bpf_testmod functions in tests
Now that we have un/load_bpf_testmod helpers in testing_helpers.h,
we can use it in other tests and save some lines.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-7-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
b58f3f0e6f selftests/bpf: Do not unload bpf_testmod in load_bpf_testmod
Do not unload bpf_testmod in load_bpf_testmod, instead call
unload_bpf_testmod separatelly.

This way we will be able use un/load_bpf_testmod functions
in other tests that un/load bpf_testmod module.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-6-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
d18decca69 selftests/bpf: Use only stdout in un/load_bpf_testmod functions
We are about to use un/load_bpf_testmod functions in couple tests
and it's better  to print output to stdout,  so it's aligned with
tests ASSERT macros output, which use stdout as well.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-5-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
45db310984 selftests/bpf: Move test_progs helpers to testing_helpers object
Moving test_progs helpers to testing_helpers object so they can be
used from test_verifier in following changes.

Also adding missing ifndef header guard to testing_helpers.h header.

Using stderr instead of env.stderr because un/load_bpf_testmod helpers
will be used outside test_progs. Also at the point of calling them
in test_progs the std files are not hijacked yet and stderr is the
same as env.stderr.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-4-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Jiri Olsa
8e9af82171 selftests/bpf: Move kfunc exports to bpf_testmod/bpf_testmod_kfunc.h
Move all kfunc exports into separate bpf_testmod_kfunc.h header file
and include it in tests that need it.

We will move all test kfuncs into bpf_testmod in following change,
so it's convenient to have declarations in single place.

The bpf_testmod_kfunc.h is included by both bpf_testmod and bpf
programs that use test kfuncs.

As suggested by David, the bpf_testmod_kfunc.h includes vmlinux.h
and bpf/bpf_helpers.h for bpf programs build, so the declarations
have proper __ksym attribute and we can resolve all the structs.

Note in kfunc_call_test_subprog.c we can no longer use the sk_state
define from bpf_tcp_helpers.h (because it clashed with vmlinux.h)
and we need to address __sk_common.skc_state field directly.

Acked-by: David Vernet <void@manifault.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Link: https://lore.kernel.org/r/20230515133756.1658301-3-jolsa@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 22:09:23 -07:00
Yonghong Song
de58ef414d selftests/bpf: Fix s390 sock_field test failure
llvm patch [1] enabled cross-function optimization for func arguments
(ArgumentPromotion) at -O2 level. And this caused s390 sock_fields
test failure ([2]). The failure is gone right now as patch [1] was
reverted in [3]. But it is possible that patch [3] will be reverted
again and then the test failure in [2] will show up again. So it is
desirable to fix the failure regardless.

The following is an analysis why sock_field test fails with
llvm patch [1].

The main problem is in
  static __noinline bool sk_dst_port__load_word(struct bpf_sock *sk)
  {
        __u32 *word = (__u32 *)&sk->dst_port;
        return word[0] == bpf_htons(0xcafe);
  }
  static __noinline bool sk_dst_port__load_half(struct bpf_sock *sk)
  {
        __u16 *half = (__u16 *)&sk->dst_port;
        return half[0] == bpf_htons(0xcafe);
  }
  ...
  int read_sk_dst_port(struct __sk_buff *skb)
  {
	...
        sk = skb->sk;
	...
        if (!sk_dst_port__load_word(sk))
                RET_LOG();
        if (!sk_dst_port__load_half(sk))
                RET_LOG();
	...
  }

Through some cross-function optimization by ArgumentPromotion
optimization, the compiler does:
  static __noinline bool sk_dst_port__load_word(__u32 word_val)
  {
        return word_val == bpf_htons(0xcafe);
  }
  static __noinline bool sk_dst_port__load_half(__u16 half_val)
  {
        return half_val == bpf_htons(0xcafe);
  }
  ...
  int read_sk_dst_port(struct __sk_buff *skb)
  {
        ...
        sk = skb->sk;
        ...
        __u32 *word = (__u32 *)&sk->dst_port;
        __u32 word_val = word[0];
        ...
        if (!sk_dst_port__load_word(word_val))
                RET_LOG();

        __u16 half_val = word_val >> 16;
        if (!sk_dst_port__load_half(half_val))
                RET_LOG();
        ...
  }

In current uapi bpf.h, we have
  struct bpf_sock {
	...
        __be16 dst_port;        /* network byte order */
        __u16 :16;              /* zero padding */
	...
  };
But the old kernel (e.g., 5.6) we have
  struct bpf_sock {
	...
	__u32 dst_port;         /* network byte order */
	...
  };

So for backward compatability reason, 4-byte load of
dst_port is converted to 2-byte load internally.
Specifically, 'word_val = word[0]' is replaced by 2-byte load
by the verifier and this caused the trouble for later
sk_dst_port__load_half() where half_val becomes 0.

Typical usr program won't have such a code pattern tiggering
the above bug, so let us fix the test failure with source
code change. Adding an empty asm volatile statement seems
enough to prevent undesired transformation.

  [1] https://reviews.llvm.org/D148269
  [2] https://lore.kernel.org/bpf/e7f2c5e8-a50c-198d-8f95-388165f1e4fd@meta.com/
  [3] https://reviews.llvm.org/rG141be5c062ecf22bd287afffd310e8ac4711444a

Tested-by: Ilya Leoshkevich <iii@linux.ibm.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230516214945.1013578-1-yhs@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 20:57:16 -07:00
Andrii Nakryiko
24a86d833b selftests/bpf: improve netcnt test robustness
Change netcnt to demand at least 10K packets, as we frequently see some
stray packet arriving during the test in BPF CI. It seems more important
to make sure we haven't lost any packet than enforcing exact number of
packets.

Cc: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230515204833.2832000-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-16 20:57:16 -07:00
Florent Revest
90564f1e3d bpf, arm64: Support struct arguments in the BPF trampoline
This extends the BPF trampoline JIT to support attachment to functions
that take small structures (up to 128bit) as argument. This is trivially
achieved by saving/restoring a number of "argument registers" rather
than a number of arguments.

The AAPCS64 section 6.8.2 describes the parameter passing ABI.
"Composite types" (like C structs) below 16 bytes (as enforced by the
BPF verifier) are provided as part of the 8 argument registers as
explained in the section C.12.

Signed-off-by: Florent Revest <revest@chromium.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Yonghong Song <yhs@fb.com>
Acked-by: Xu Kuohai <xukuohai@huawei.com>
Link: https://lore.kernel.org/bpf/20230511140507.514888-1-revest@chromium.org
2023-05-15 21:17:22 +02:00
Jeremy Sowden
5f5486b620 selftests/bpf: Fix pkg-config call building sign-file
When building sign-file, the call to get the CFLAGS for libcrypto is
missing white-space between `pkg-config` and `--cflags`:

  $(shell $(HOSTPKG_CONFIG)--cflags libcrypto 2> /dev/null)

Removing the redirection of stderr, we see:

  $ make -C tools/testing/selftests/bpf sign-file
  make: Entering directory '[...]/tools/testing/selftests/bpf'
  make: pkg-config--cflags: No such file or directory
    SIGN-FILE sign-file
  make: Leaving directory '[...]/tools/testing/selftests/bpf'

Add the missing space.

Fixes: fc97590668 ("selftests/bpf: Add test for bpf_verify_pkcs7_signature() kfunc")
Signed-off-by: Jeremy Sowden <jeremy@azazel.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Link: https://lore.kernel.org/bpf/20230426215032.415792-1-jeremy@azazel.net
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-14 14:59:44 -07:00
Stanislav Fomichev
e01b4a72f1 selftests/bpf: Correctly handle optlen > 4096
Even though it's not relevant in selftests, the people
might still copy-paste from them. So let's take care
of optlen > 4096 cases explicitly.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230511170456.1759459-4-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-13 16:55:46 -07:00
Stanislav Fomichev
989a4a7dbf selftests/bpf: Update EFAULT {g,s}etsockopt selftests
Instead of assuming EFAULT, let's assume the BPF program's
output is ignored.

Remove "getsockopt: deny arbitrary ctx->retval" because it
was actually testing optlen. We have separate set of tests
for retval.

Signed-off-by: Stanislav Fomichev <sdf@google.com>
Link: https://lore.kernel.org/r/20230511170456.1759459-3-sdf@google.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
2023-05-13 16:55:44 -07:00
Daniel Rosenberg
798e48fc28 selftests/bpf: Accept mem from dynptr in helper funcs
This ensures that buffers retrieved from dynptr_data are allowed to be
passed in to helpers that take mem, like bpf_strncmp

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-6-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 16:42:58 -07:00
Daniel Rosenberg
3881fdfed2 selftests/bpf: Check overflow in optional buffer
This ensures we still reject invalid memory accesses in buffers that are
marked optional.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-4-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 16:42:57 -07:00
Daniel Rosenberg
1ce33b6c84 selftests/bpf: Test allowing NULL buffer in dynptr slice
bpf_dynptr_slice(_rw) no longer requires a buffer for verification. If the
buffer is needed, but not present, the function will return NULL.

Signed-off-by: Daniel Rosenberg <drosen@google.com>
Link: https://lore.kernel.org/r/20230506013134.2492210-3-drosen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 16:42:57 -07:00
Feng Zhou
49e0263ab4 selftests/bpf: Add testcase for bpf_task_under_cgroup
test_progs:
Tests new kfunc bpf_task_under_cgroup().

The bpf program saves the new task's pid within a given cgroup to
the remote_pid, which is convenient for the user-mode program to
verify the test correctness.

The user-mode program creates its own mount namespace, and mounts the
cgroupsv2 hierarchy in there, call the fork syscall, then check if
remote_pid and local_pid are unequal.

Signed-off-by: Feng Zhou <zhoufeng.zf@bytedance.com>
Acked-by: Yonghong Song <yhs@fb.com>
Link: https://lore.kernel.org/r/20230506031545.35991-3-zhoufeng.zf@bytedance.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-06 13:56:38 -07:00
Andrii Nakryiko
c91ab90cea selftests/bpf: revert iter test subprog precision workaround
Now that precision propagation is supported fully in the presence of
subprogs, there is no need to work around iter test. Revert original
workaround.

This reverts be7dbd275d ("selftests/bpf: avoid mark_all_scalars_precise() trigger in one of iter tests").

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-11-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
3ef3d2177b selftests/bpf: add precision propagation tests in the presence of subprogs
Add a bunch of tests validating verifier's precision backpropagation
logic in the presence of subprog calls and/or callback-calling
helpers/kfuncs.

We validate the following conditions:
  - subprog_result_precise: static subprog r0 result precision handling;
  - global_subprog_result_precise: global subprog r0 precision
    shortcutting, similar to BPF helper handling;
  - callback_result_precise: similarly r0 marking precise for
    callback-calling helpers;
  - parent_callee_saved_reg_precise, parent_callee_saved_reg_precise_global:
    propagation of precision for callee-saved registers bypassing
    static/global subprogs;
  - parent_callee_saved_reg_precise_with_callback: same as above, but in
    the presence of callback-calling helper;
  - parent_stack_slot_precise, parent_stack_slot_precise_global:
    similar to above, but instead propagating precision of stack slot
    (spilled SCALAR reg);
  - parent_stack_slot_precise_with_callback: same as above, but in the
    presence of callback-calling helper;
  - subprog_arg_precise: propagation of precision of static subprog's
    input argument back to caller;
  - subprog_spill_into_parent_stack_slot_precise: negative test
    validating that verifier currently can't support backtracking of stack
    access with non-r10 register, we validate that we fallback to
    forcing precision for all SCALARs.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-10-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
c50c0b57a5 bpf: fix mark_all_scalars_precise use in mark_chain_precision
When precision backtracking bails out due to some unsupported sequence
of instructions (e.g., stack access through register other than r10), we
need to mark all SCALAR registers as precise to be safe. Currently,
though, we mark SCALARs precise only starting from the state we detected
unsupported condition, which could be one of the parent states of the
actual current state. This will leave some registers potentially not
marked as precise, even though they should. So make sure we start
marking scalars as precise from current state (env->cur_state).

Further, we don't currently detect a situation when we end up with some
stack slots marked as needing precision, but we ran out of available
states to find the instructions that populate those stack slots. This is
akin the `i >= func->allocated_stack / BPF_REG_SIZE` check and should be
handled similarly by falling back to marking all SCALARs precise. Add
this check when we run out of states.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-8-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00
Andrii Nakryiko
1ef22b6865 bpf: maintain bitmasks across all active frames in __mark_chain_precision
Teach __mark_chain_precision logic to maintain register/stack masks
across all active frames when going from child state to parent state.
Currently this should be mostly no-op, as precision backtracking usually
bails out when encountering subprog entry/exit.

It's not very apparent from the diff due to increased indentation, but
the logic remains the same, except everything is done on specific `fr`
frame index. Calls to bt_clear_reg() and bt_clear_slot() are replaced
with frame-specific bt_clear_frame_reg() and bt_clear_frame_slot(),
where frame index is passed explicitly, instead of using current frame
number.

We also adjust logging to emit affected frame number. And we also add
better logging of human-readable register and stack slot masks, similar
to previous patch.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/r/20230505043317.3629845-6-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2023-05-04 22:35:35 -07:00