1 ================== 1 ==================
2 BPF Selftest Notes 2 BPF Selftest Notes
3 ================== 3 ==================
4 General instructions on running selftests can 4 General instructions on running selftests can be found in
5 `Documentation/bpf/bpf_devel_QA.rst`__. 5 `Documentation/bpf/bpf_devel_QA.rst`__.
6 6
7 __ /Documentation/bpf/bpf_devel_QA.rst#q-how-t 7 __ /Documentation/bpf/bpf_devel_QA.rst#q-how-to-run-bpf-selftests
8 8
9 ============= 9 =============
10 BPF CI System 10 BPF CI System
11 ============= 11 =============
12 12
13 BPF employs a continuous integration (CI) syst 13 BPF employs a continuous integration (CI) system to check patch submission in an
14 automated fashion. The system runs selftests f 14 automated fashion. The system runs selftests for each patch in a series. Results
15 are propagated to patchwork, where failures ar 15 are propagated to patchwork, where failures are highlighted similar to
16 violations of other checks (such as additional 16 violations of other checks (such as additional warnings being emitted or a
17 ``scripts/checkpatch.pl`` reported deficiency) 17 ``scripts/checkpatch.pl`` reported deficiency):
18 18
19 https://patchwork.kernel.org/project/netdevb 19 https://patchwork.kernel.org/project/netdevbpf/list/?delegate=121173
20 20
21 The CI system executes tests on multiple archi 21 The CI system executes tests on multiple architectures. It uses a kernel
22 configuration derived from both the generic an 22 configuration derived from both the generic and architecture specific config
23 file fragments below ``tools/testing/selftests 23 file fragments below ``tools/testing/selftests/bpf/`` (e.g., ``config`` and
24 ``config.x86_64``). 24 ``config.x86_64``).
25 25
26 Denylisting Tests 26 Denylisting Tests
27 ================= 27 =================
28 28
29 It is possible for some architectures to not h 29 It is possible for some architectures to not have support for all BPF features.
30 In such a case tests in CI may fail. An exampl 30 In such a case tests in CI may fail. An example of such a shortcoming is BPF
31 trampoline support on IBM's s390x architecture 31 trampoline support on IBM's s390x architecture. For cases like this, an in-tree
32 deny list file, located at ``tools/testing/sel 32 deny list file, located at ``tools/testing/selftests/bpf/DENYLIST.<arch>``, can
33 be used to prevent the test from running on su 33 be used to prevent the test from running on such an architecture.
34 34
35 In addition to that, the generic ``tools/testi 35 In addition to that, the generic ``tools/testing/selftests/bpf/DENYLIST`` is
36 honored on every architecture running tests. 36 honored on every architecture running tests.
37 37
38 These files are organized in three columns. Th 38 These files are organized in three columns. The first column lists the test in
39 question. This can be the name of a test suite 39 question. This can be the name of a test suite or of an individual test. The
40 remaining two columns provide additional meta 40 remaining two columns provide additional meta data that helps identify and
41 classify the entry: column two is a copy and p 41 classify the entry: column two is a copy and paste of the error being reported
42 when running the test in the setting in questi 42 when running the test in the setting in question. The third column, if
43 available, summarizes the underlying problem. 43 available, summarizes the underlying problem. A value of ``trampoline``, for
44 example, indicates that lack of trampoline sup 44 example, indicates that lack of trampoline support is causing the test to fail.
45 This last entry helps identify tests that can 45 This last entry helps identify tests that can be re-enabled once such support is
46 added. 46 added.
47 47
48 ========================= 48 =========================
49 Running Selftests in a VM 49 Running Selftests in a VM
50 ========================= 50 =========================
51 51
52 It's now possible to run the selftests using ` 52 It's now possible to run the selftests using ``tools/testing/selftests/bpf/vmtest.sh``.
53 The script tries to ensure that the tests are 53 The script tries to ensure that the tests are run with the same environment as they
54 would be run post-submit in the CI used by the 54 would be run post-submit in the CI used by the Maintainers, with the exception
55 that deny lists are not automatically honored. 55 that deny lists are not automatically honored.
56 56
57 This script uses the in-tree kernel configurat 57 This script uses the in-tree kernel configuration and downloads a VM userspace
58 image from the system used by the CI. It build 58 image from the system used by the CI. It builds the kernel (without overwriting
59 your existing Kconfig), recompiles the bpf sel 59 your existing Kconfig), recompiles the bpf selftests, runs them (by default
60 ``tools/testing/selftests/bpf/test_progs``) an 60 ``tools/testing/selftests/bpf/test_progs``) and saves the resulting output (by
61 default in ``~/.bpf_selftests``). 61 default in ``~/.bpf_selftests``).
62 62
63 Script dependencies: 63 Script dependencies:
64 - clang (preferably built from sources, https: 64 - clang (preferably built from sources, https://github.com/llvm/llvm-project);
65 - pahole (preferably built from sources, https 65 - pahole (preferably built from sources, https://git.kernel.org/pub/scm/devel/pahole/pahole.git/);
66 - qemu; 66 - qemu;
67 - docutils (for ``rst2man``); 67 - docutils (for ``rst2man``);
68 - libcap-devel. 68 - libcap-devel.
69 69
70 For more information about using the script, r 70 For more information about using the script, run:
71 71
72 .. code-block:: console 72 .. code-block:: console
73 73
74 $ tools/testing/selftests/bpf/vmtest.sh -h 74 $ tools/testing/selftests/bpf/vmtest.sh -h
75 75
76 In case of linker errors when running selftest 76 In case of linker errors when running selftests, try using static linking:
77 77
78 .. code-block:: console 78 .. code-block:: console
79 79
80 $ LDLIBS=-static PKG_CONFIG='pkg-config --st 80 $ LDLIBS=-static PKG_CONFIG='pkg-config --static' vmtest.sh
81 81
82 .. note:: Some distros may not support static 82 .. note:: Some distros may not support static linking.
83 83
84 .. note:: The script uses pahole and clang bas 84 .. note:: The script uses pahole and clang based on host environment setting.
85 If you want to change pahole and llv 85 If you want to change pahole and llvm, you can change `PATH` environment
86 variable in the beginning of script. 86 variable in the beginning of script.
87 87
88 Running vmtest on RV64 88 Running vmtest on RV64
89 ====================== 89 ======================
90 To speed up testing and avoid various dependen 90 To speed up testing and avoid various dependency issues, it is recommended to
91 run vmtest in a Docker container. Before runni 91 run vmtest in a Docker container. Before running vmtest, we need to prepare
92 Docker container and local rootfs image. The o 92 Docker container and local rootfs image. The overall steps are as follows:
93 93
94 1. Create Docker container as shown in link [0 94 1. Create Docker container as shown in link [0].
95 95
96 2. Use mkrootfs_debian.sh script [1] to build 96 2. Use mkrootfs_debian.sh script [1] to build local rootfs image:
97 97
98 .. code-block:: console 98 .. code-block:: console
99 99
100 $ sudo ./mkrootfs_debian.sh --arch riscv64 - 100 $ sudo ./mkrootfs_debian.sh --arch riscv64 --distro noble
101 101
102 3. Start Docker container [0] and run vmtest i 102 3. Start Docker container [0] and run vmtest in the container:
103 103
104 .. code-block:: console 104 .. code-block:: console
105 105
106 $ PLATFORM=riscv64 CROSS_COMPILE=riscv64-lin 106 $ PLATFORM=riscv64 CROSS_COMPILE=riscv64-linux-gnu- \
107 tools/testing/selftests/bpf/vmtest.sh \ 107 tools/testing/selftests/bpf/vmtest.sh \
108 -l <path of local rootfs image> -- \ 108 -l <path of local rootfs image> -- \
109 ./test_progs -d \ 109 ./test_progs -d \
110 \"$(cat tools/testing/selftests/bpf/DE 110 \"$(cat tools/testing/selftests/bpf/DENYLIST.riscv64 \
111 | cut -d'#' -f1 \ 111 | cut -d'#' -f1 \
112 | sed -e 's/^[[:space:]]*//' \ 112 | sed -e 's/^[[:space:]]*//' \
113 -e 's/[[:space:]]*$//' \ 113 -e 's/[[:space:]]*$//' \
114 | tr -s '\n' ',' \ 114 | tr -s '\n' ',' \
115 )\" 115 )\"
116 116
117 Link: https://github.com/pulehui/riscv-bpf-vmt 117 Link: https://github.com/pulehui/riscv-bpf-vmtest.git [0]
118 Link: https://github.com/libbpf/ci/blob/main/r 118 Link: https://github.com/libbpf/ci/blob/main/rootfs/mkrootfs_debian.sh [1]
119 119
120 Additional information about selftest failures 120 Additional information about selftest failures are
121 documented here. 121 documented here.
122 122
123 profiler[23] test failures with clang/llvm <12 123 profiler[23] test failures with clang/llvm <12.0.0
124 ============================================== 124 ==================================================
125 125
126 With clang/llvm <12.0.0, the profiler[23] test 126 With clang/llvm <12.0.0, the profiler[23] test may fail.
127 The symptom looks like 127 The symptom looks like
128 128
129 .. code-block:: c 129 .. code-block:: c
130 130
131 // r9 is a pointer to map_value 131 // r9 is a pointer to map_value
132 // r7 is a scalar 132 // r7 is a scalar
133 17: bf 96 00 00 00 00 00 00 r6 = r9 133 17: bf 96 00 00 00 00 00 00 r6 = r9
134 18: 0f 76 00 00 00 00 00 00 r6 += r7 134 18: 0f 76 00 00 00 00 00 00 r6 += r7
135 math between map_value pointer and register 135 math between map_value pointer and register with unbounded min value is not allowed
136 136
137 // the instructions below will not be seen i 137 // the instructions below will not be seen in the verifier log
138 19: a5 07 01 00 01 01 00 00 if r7 < 25 138 19: a5 07 01 00 01 01 00 00 if r7 < 257 goto +1
139 20: bf 96 00 00 00 00 00 00 r6 = r9 139 20: bf 96 00 00 00 00 00 00 r6 = r9
140 // r6 is used here 140 // r6 is used here
141 141
142 The verifier will reject such code with above 142 The verifier will reject such code with above error.
143 At insn 18 the r7 is indeed unbounded. The lat 143 At insn 18 the r7 is indeed unbounded. The later insn 19 checks the bounds and
144 the insn 20 undoes map_value addition. It is c 144 the insn 20 undoes map_value addition. It is currently impossible for the
145 verifier to understand such speculative pointe 145 verifier to understand such speculative pointer arithmetic.
146 Hence `this patch`__ addresses it on the compi 146 Hence `this patch`__ addresses it on the compiler side. It was committed on llvm 12.
147 147
148 __ https://github.com/llvm/llvm-project/commit 148 __ https://github.com/llvm/llvm-project/commit/ddf1864ace484035e3cde5e83b3a31ac81e059c6
149 149
150 The corresponding C code 150 The corresponding C code
151 151
152 .. code-block:: c 152 .. code-block:: c
153 153
154 for (int i = 0; i < MAX_CGROUPS_PATH_DEPTH; 154 for (int i = 0; i < MAX_CGROUPS_PATH_DEPTH; i++) {
155 filepart_length = bpf_probe_read_str 155 filepart_length = bpf_probe_read_str(payload, ...);
156 if (filepart_length <= MAX_PATH) { 156 if (filepart_length <= MAX_PATH) {
157 barrier_var(filepart_length) 157 barrier_var(filepart_length); // workaround
158 payload += filepart_length; 158 payload += filepart_length;
159 } 159 }
160 } 160 }
161 161
162 bpf_iter test failures with clang/llvm 10.0.0 162 bpf_iter test failures with clang/llvm 10.0.0
163 ============================================= 163 =============================================
164 164
165 With clang/llvm 10.0.0, the following two bpf_ 165 With clang/llvm 10.0.0, the following two bpf_iter tests failed:
166 * ``bpf_iter/ipv6_route`` 166 * ``bpf_iter/ipv6_route``
167 * ``bpf_iter/netlink`` 167 * ``bpf_iter/netlink``
168 168
169 The symptom for ``bpf_iter/ipv6_route`` looks 169 The symptom for ``bpf_iter/ipv6_route`` looks like
170 170
171 .. code-block:: c 171 .. code-block:: c
172 172
173 2: (79) r8 = *(u64 *)(r1 +8) 173 2: (79) r8 = *(u64 *)(r1 +8)
174 ... 174 ...
175 14: (bf) r2 = r8 175 14: (bf) r2 = r8
176 15: (0f) r2 += r1 176 15: (0f) r2 += r1
177 ; BPF_SEQ_PRINTF(seq, "%pi6 %02x ", &rt->fib 177 ; BPF_SEQ_PRINTF(seq, "%pi6 %02x ", &rt->fib6_dst.addr, rt->fib6_dst.plen);
178 16: (7b) *(u64 *)(r8 +64) = r2 178 16: (7b) *(u64 *)(r8 +64) = r2
179 only read is supported 179 only read is supported
180 180
181 The symptom for ``bpf_iter/netlink`` looks lik 181 The symptom for ``bpf_iter/netlink`` looks like
182 182
183 .. code-block:: c 183 .. code-block:: c
184 184
185 ; struct netlink_sock *nlk = ctx->sk; 185 ; struct netlink_sock *nlk = ctx->sk;
186 2: (79) r7 = *(u64 *)(r1 +8) 186 2: (79) r7 = *(u64 *)(r1 +8)
187 ... 187 ...
188 15: (bf) r2 = r7 188 15: (bf) r2 = r7
189 16: (0f) r2 += r1 189 16: (0f) r2 += r1
190 ; BPF_SEQ_PRINTF(seq, "%pK %-3d ", s, s->sk_ 190 ; BPF_SEQ_PRINTF(seq, "%pK %-3d ", s, s->sk_protocol);
191 17: (7b) *(u64 *)(r7 +0) = r2 191 17: (7b) *(u64 *)(r7 +0) = r2
192 only read is supported 192 only read is supported
193 193
194 This is due to a llvm BPF backend bug. `The fi 194 This is due to a llvm BPF backend bug. `The fix`__
195 has been pushed to llvm 10.x release branch an 195 has been pushed to llvm 10.x release branch and will be
196 available in 10.0.1. The patch is available in 196 available in 10.0.1. The patch is available in llvm 11.0.0 trunk.
197 197
198 __ https://github.com/llvm/llvm-project/commi 198 __ https://github.com/llvm/llvm-project/commit/3cb7e7bf959dcd3b8080986c62e10a75c7af43f0
199 199
200 bpf_verif_scale/loop6.bpf.o test failure with 200 bpf_verif_scale/loop6.bpf.o test failure with Clang 12
201 ============================================== 201 ======================================================
202 202
203 With Clang 12, the following bpf_verif_scale t 203 With Clang 12, the following bpf_verif_scale test failed:
204 * ``bpf_verif_scale/loop6.bpf.o`` 204 * ``bpf_verif_scale/loop6.bpf.o``
205 205
206 The verifier output looks like 206 The verifier output looks like
207 207
208 .. code-block:: c 208 .. code-block:: c
209 209
210 R1 type=ctx expected=fp 210 R1 type=ctx expected=fp
211 The sequence of 8193 jumps is too complex. 211 The sequence of 8193 jumps is too complex.
212 212
213 The reason is compiler generating the followin 213 The reason is compiler generating the following code
214 214
215 .. code-block:: c 215 .. code-block:: c
216 216
217 ; for (i = 0; (i < VIRTIO_MAX_SGS) && 217 ; for (i = 0; (i < VIRTIO_MAX_SGS) && (i < num); i++) {
218 14: 16 05 40 00 00 00 00 00 if w5 218 14: 16 05 40 00 00 00 00 00 if w5 == 0 goto +64 <LBB0_6>
219 15: bc 51 00 00 00 00 00 00 w1 = w 219 15: bc 51 00 00 00 00 00 00 w1 = w5
220 16: 04 01 00 00 ff ff ff ff w1 += 220 16: 04 01 00 00 ff ff ff ff w1 += -1
221 17: 67 05 00 00 20 00 00 00 r5 <<= 221 17: 67 05 00 00 20 00 00 00 r5 <<= 32
222 18: 77 05 00 00 20 00 00 00 r5 >>= 222 18: 77 05 00 00 20 00 00 00 r5 >>= 32
223 19: a6 01 01 00 05 00 00 00 if w1 223 19: a6 01 01 00 05 00 00 00 if w1 < 5 goto +1 <LBB0_4>
224 20: b7 05 00 00 06 00 00 00 r5 = 6 224 20: b7 05 00 00 06 00 00 00 r5 = 6
225 00000000000000a8 <LBB0_4>: 225 00000000000000a8 <LBB0_4>:
226 21: b7 02 00 00 00 00 00 00 r2 = 0 226 21: b7 02 00 00 00 00 00 00 r2 = 0
227 22: b7 01 00 00 00 00 00 00 r1 = 0 227 22: b7 01 00 00 00 00 00 00 r1 = 0
228 ; for (i = 0; (i < VIRTIO_MAX_SGS) && 228 ; for (i = 0; (i < VIRTIO_MAX_SGS) && (i < num); i++) {
229 23: 7b 1a e0 ff 00 00 00 00 *(u64 229 23: 7b 1a e0 ff 00 00 00 00 *(u64 *)(r10 - 32) = r1
230 24: 7b 5a c0 ff 00 00 00 00 *(u64 230 24: 7b 5a c0 ff 00 00 00 00 *(u64 *)(r10 - 64) = r5
231 231
232 Note that insn #15 has w1 = w5 and w1 is refin 232 Note that insn #15 has w1 = w5 and w1 is refined later but
233 r5(w5) is eventually saved on stack at insn #2 233 r5(w5) is eventually saved on stack at insn #24 for later use.
234 This cause later verifier failure. The bug has 234 This cause later verifier failure. The bug has been `fixed`__ in
235 Clang 13. 235 Clang 13.
236 236
237 __ https://github.com/llvm/llvm-project/commi 237 __ https://github.com/llvm/llvm-project/commit/1959ead525b8830cc8a345f45e1c3ef9902d3229
238 238
239 BPF CO-RE-based tests and Clang version 239 BPF CO-RE-based tests and Clang version
240 ======================================= 240 =======================================
241 241
242 A set of selftests use BPF target-specific bui 242 A set of selftests use BPF target-specific built-ins, which might require
243 bleeding-edge Clang versions (Clang 12 nightly 243 bleeding-edge Clang versions (Clang 12 nightly at this time).
244 244
245 Few sub-tests of core_reloc test suit (part of 245 Few sub-tests of core_reloc test suit (part of test_progs test runner) require
246 the following built-ins, listed with correspon 246 the following built-ins, listed with corresponding Clang diffs introducing
247 them to Clang/LLVM. These sub-tests are going 247 them to Clang/LLVM. These sub-tests are going to be skipped if Clang is too
248 old to support them, they shouldn't cause buil 248 old to support them, they shouldn't cause build failures or runtime test
249 failures: 249 failures:
250 250
251 - __builtin_btf_type_id() [0_, 1_, 2_]; 251 - __builtin_btf_type_id() [0_, 1_, 2_];
252 - __builtin_preserve_type_info(), __builtin_pr 252 - __builtin_preserve_type_info(), __builtin_preserve_enum_value() [3_, 4_].
253 253
254 .. _0: https://github.com/llvm/llvm-project/co 254 .. _0: https://github.com/llvm/llvm-project/commit/6b01b465388b204d543da3cf49efd6080db094a9
255 .. _1: https://github.com/llvm/llvm-project/co 255 .. _1: https://github.com/llvm/llvm-project/commit/072cde03aaa13a2c57acf62d79876bf79aa1919f
256 .. _2: https://github.com/llvm/llvm-project/co 256 .. _2: https://github.com/llvm/llvm-project/commit/00602ee7ef0bf6c68d690a2bd729c12b95c95c99
257 .. _3: https://github.com/llvm/llvm-project/co 257 .. _3: https://github.com/llvm/llvm-project/commit/6d218b4adb093ff2e9764febbbc89f429412006c
258 .. _4: https://github.com/llvm/llvm-project/co 258 .. _4: https://github.com/llvm/llvm-project/commit/6d6750696400e7ce988d66a1a00e1d0cb32815f8
259 259
260 Floating-point tests and Clang version 260 Floating-point tests and Clang version
261 ====================================== 261 ======================================
262 262
263 Certain selftests, e.g. core_reloc, require su 263 Certain selftests, e.g. core_reloc, require support for the floating-point
264 types, which was introduced in `Clang 13`__. T 264 types, which was introduced in `Clang 13`__. The older Clang versions will
265 either crash when compiling these tests, or ge 265 either crash when compiling these tests, or generate an incorrect BTF.
266 266
267 __ https://github.com/llvm/llvm-project/commi 267 __ https://github.com/llvm/llvm-project/commit/a7137b238a07d9399d3ae96c0b461571bd5aa8b2
268 268
269 Kernel function call test and Clang version 269 Kernel function call test and Clang version
270 =========================================== 270 ===========================================
271 271
272 Some selftests (e.g. kfunc_call and bpf_tcp_ca 272 Some selftests (e.g. kfunc_call and bpf_tcp_ca) require a LLVM support
273 to generate extern function in BTF. It was in 273 to generate extern function in BTF. It was introduced in `Clang 13`__.
274 274
275 Without it, the error from compiling bpf selft 275 Without it, the error from compiling bpf selftests looks like:
276 276
277 .. code-block:: console 277 .. code-block:: console
278 278
279 libbpf: failed to find BTF for extern 'tcp_s 279 libbpf: failed to find BTF for extern 'tcp_slow_start' [25] section: -2
280 280
281 __ https://github.com/llvm/llvm-project/commit 281 __ https://github.com/llvm/llvm-project/commit/886f9ff53155075bd5f1e994f17b85d1e1b7470c
282 282
283 btf_tag test and Clang version 283 btf_tag test and Clang version
284 ============================== 284 ==============================
285 285
286 The btf_tag selftest requires LLVM support to 286 The btf_tag selftest requires LLVM support to recognize the btf_decl_tag and
287 btf_type_tag attributes. They are introduced i 287 btf_type_tag attributes. They are introduced in `Clang 14` [0_, 1_].
288 The subtests ``btf_type_tag_user_{mod1, mod2, 288 The subtests ``btf_type_tag_user_{mod1, mod2, vmlinux}`` also requires
289 pahole version ``1.23``. 289 pahole version ``1.23``.
290 290
291 Without them, the btf_tag selftest will be ski 291 Without them, the btf_tag selftest will be skipped and you will observe:
292 292
293 .. code-block:: console 293 .. code-block:: console
294 294
295 #<test_num> btf_tag:SKIP 295 #<test_num> btf_tag:SKIP
296 296
297 .. _0: https://github.com/llvm/llvm-project/co 297 .. _0: https://github.com/llvm/llvm-project/commit/a162b67c98066218d0d00aa13b99afb95d9bb5e6
298 .. _1: https://github.com/llvm/llvm-project/co 298 .. _1: https://github.com/llvm/llvm-project/commit/3466e00716e12e32fdb100e3fcfca5c2b3e8d784
299 299
300 Clang dependencies for static linking tests 300 Clang dependencies for static linking tests
301 =========================================== 301 ===========================================
302 302
303 linked_vars, linked_maps, and linked_funcs tes 303 linked_vars, linked_maps, and linked_funcs tests depend on `Clang fix`__ to
304 generate valid BTF information for weak variab 304 generate valid BTF information for weak variables. Please make sure you use
305 Clang that contains the fix. 305 Clang that contains the fix.
306 306
307 __ https://github.com/llvm/llvm-project/commit 307 __ https://github.com/llvm/llvm-project/commit/968292cb93198442138128d850fd54dc7edc0035
308 308
309 Clang relocation changes 309 Clang relocation changes
310 ======================== 310 ========================
311 311
312 Clang 13 patch `clang reloc patch`_ made some 312 Clang 13 patch `clang reloc patch`_ made some changes on relocations such
313 that existing relocation types are broken into 313 that existing relocation types are broken into more types and
314 each new type corresponds to only one way to r 314 each new type corresponds to only one way to resolve relocation.
315 See `kernel llvm reloc`_ for more explanation 315 See `kernel llvm reloc`_ for more explanation and some examples.
316 Using clang 13 to compile old libbpf which has 316 Using clang 13 to compile old libbpf which has static linker support,
317 there will be a compilation failure:: 317 there will be a compilation failure::
318 318
319 libbpf: ELF relo #0 in section #6 has unexpe 319 libbpf: ELF relo #0 in section #6 has unexpected type 2 in .../bpf_tcp_nogpl.bpf.o
320 320
321 Here, ``type 2`` refers to new relocation type 321 Here, ``type 2`` refers to new relocation type ``R_BPF_64_ABS64``.
322 To fix this issue, user newer libbpf. 322 To fix this issue, user newer libbpf.
323 323
324 .. Links 324 .. Links
325 .. _clang reloc patch: https://github.com/llvm 325 .. _clang reloc patch: https://github.com/llvm/llvm-project/commit/6a2ea84600ba4bd3b2733bd8f08f5115eb32164b
326 .. _kernel llvm reloc: /Documentation/bpf/llvm 326 .. _kernel llvm reloc: /Documentation/bpf/llvm_reloc.rst
327 327
328 Clang dependencies for the u32 spill test (xdp 328 Clang dependencies for the u32 spill test (xdpwall)
329 ============================================== 329 ===================================================
330 The xdpwall selftest requires a change in `Cla 330 The xdpwall selftest requires a change in `Clang 14`__.
331 331
332 Without it, the xdpwall selftest will fail and 332 Without it, the xdpwall selftest will fail and the error message
333 from running test_progs will look like: 333 from running test_progs will look like:
334 334
335 .. code-block:: console 335 .. code-block:: console
336 336
337 test_xdpwall:FAIL:Does LLVM have https://git 337 test_xdpwall:FAIL:Does LLVM have https://github.com/llvm/llvm-project/commit/ea72b0319d7b0f0c2fcf41d121afa5d031b319d5? unexpected error: -4007
338 338
339 __ https://github.com/llvm/llvm-project/commit 339 __ https://github.com/llvm/llvm-project/commit/ea72b0319d7b0f0c2fcf41d121afa5d031b319d5
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.