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* bpf, selftests: Add ringbuf memory type confusion testDaniel Borkmann2022-01-192-2/+33
| | | | | | | | | | Add two tests, one which asserts that ring buffer memory can be passed to other helpers for populating its entry area, and another one where verifier rejects different type of memory passed to bpf_ringbuf_submit(). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* bpf, selftests: Add various ringbuf tests with invalid offsetDaniel Borkmann2022-01-191-0/+64
| | | | | | | | | | | | | | Assert that the verifier is rejecting invalid offsets on the ringbuf entries: # ./test_verifier | grep ring #947/u ringbuf: invalid reservation offset 1 OK #947/p ringbuf: invalid reservation offset 1 OK #948/u ringbuf: invalid reservation offset 2 OK #948/p ringbuf: invalid reservation offset 2 OK Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2022-01-071-0/+28
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2022-01-06 We've added 41 non-merge commits during the last 2 day(s) which contain a total of 36 files changed, 1214 insertions(+), 368 deletions(-). The main changes are: 1) Various fixes in the verifier, from Kris and Daniel. 2) Fixes in sockmap, from John. 3) bpf_getsockopt fix, from Kuniyuki. 4) INET_POST_BIND fix, from Menglong. 5) arm64 JIT fix for bpf pseudo funcs, from Hou. 6) BPF ISA doc improvements, from Christoph. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (41 commits) bpf: selftests: Add bind retry for post_bind{4, 6} bpf: selftests: Use C99 initializers in test_sock.c net: bpf: Handle return value of BPF_CGROUP_RUN_PROG_INET{4,6}_POST_BIND() bpf/selftests: Test bpf_d_path on rdonly_mem. libbpf: Add documentation for bpf_map batch operations selftests/bpf: Don't rely on preserving volatile in PT_REGS macros in loop3 xdp: Add xdp_do_redirect_frame() for pre-computed xdp_frames xdp: Move conversion to xdp_frame out of map functions page_pool: Store the XDP mem id page_pool: Add callback to init pages when they are allocated xdp: Allow registering memory model without rxq reference samples/bpf: xdpsock: Add timestamp for Tx-only operation samples/bpf: xdpsock: Add time-out for cleaning Tx samples/bpf: xdpsock: Add sched policy and priority support samples/bpf: xdpsock: Add cyclic TX operation capability samples/bpf: xdpsock: Add clockid selection support samples/bpf: xdpsock: Add Dest and Src MAC setting for Tx-only operation samples/bpf: xdpsock: Add VLAN support for Tx-only operation libbpf 1.0: Deprecate bpf_object__find_map_by_offset() API libbpf 1.0: Deprecate bpf_map__is_offload_neutral() ... ==================== Link: https://lore.kernel.org/r/20220107013626.53943-1-alexei.starovoitov@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf, selftests: Add verifier test for mem_or_null register with offset.Daniel Borkmann2022-01-051-0/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | Add a new test case with mem_or_null typed register with off > 0 to ensure it gets rejected by the verifier: # ./test_verifier 1011 #1009/u check with invalid reg offset 0 OK #1009/p check with invalid reg offset 0 OK Summary: 2 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2022-01-051-1/+1
|\ \ | |/ |/| | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf, selftests: Fix spelling mistake "tained" -> "tainted"Colin Ian King2021-12-171-1/+1
| | | | | | | | | | | | | | | | There appears to be a spelling mistake in a bpf test message. Fix it. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211217182400.39296-1-colin.i.king@gmail.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2021-12-311-0/+12
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-12-30 The following pull-request contains BPF updates for your *net-next* tree. We've added 72 non-merge commits during the last 20 day(s) which contain a total of 223 files changed, 3510 insertions(+), 1591 deletions(-). The main changes are: 1) Automatic setrlimit in libbpf when bpf is memcg's in the kernel, from Andrii. 2) Beautify and de-verbose verifier logs, from Christy. 3) Composable verifier types, from Hao. 4) bpf_strncmp helper, from Hou. 5) bpf.h header dependency cleanup, from Jakub. 6) get_func_[arg|ret|arg_cnt] helpers, from Jiri. 7) Sleepable local storage, from KP. 8) Extend kfunc with PTR_TO_CTX, PTR_TO_MEM argument support, from Kumar. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * | selftests/bpf: Add test to access int ptr argument in tracing programJiri Olsa2021-12-131-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adding verifier test for accessing int pointer argument in tracing programs. The test program loads 2nd argument of bpf_modify_return_test function which is int pointer and checks that verifier allows that. Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211208193245.172141-3-jolsa@kernel.org
* | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-12-175-0/+306
|\ \ \ | |/ / |/| / | |/ | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf, selftests: Add test case trying to taint map value pointerDaniel Borkmann2021-12-161-0/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a test case which tries to taint map value pointer arithmetic into a unknown scalar with subsequent export through the map. Before fix: # ./test_verifier 1186 #1186/u map access: trying to leak tained dst reg FAIL Unexpected success to load! verification time 24 usec stack depth 8 processed 15 insns (limit 1000000) max_states_per_insn 0 total_states 1 peak_states 1 mark_read 1 #1186/p map access: trying to leak tained dst reg FAIL Unexpected success to load! verification time 8 usec stack depth 8 processed 15 insns (limit 1000000) max_states_per_insn 0 total_states 1 peak_states 1 mark_read 1 Summary: 0 PASSED, 0 SKIPPED, 2 FAILED After fix: # ./test_verifier 1186 #1186/u map access: trying to leak tained dst reg OK #1186/p map access: trying to leak tained dst reg OK Summary: 2 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, selftests: Update test case for atomic cmpxchg on r0 with pointerDaniel Borkmann2021-12-151-2/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix up unprivileged test case results for 'Dest pointer in r0' verifier tests given they now need to reject R0 containing a pointer value, and add a couple of new related ones with 32bit cmpxchg as well. root@foo:~/bpf/tools/testing/selftests/bpf# ./test_verifier #0/u invalid and of negative number OK #0/p invalid and of negative number OK [...] #1268/p XDP pkt read, pkt_meta' <= pkt_data, bad access 1 OK #1269/p XDP pkt read, pkt_meta' <= pkt_data, bad access 2 OK #1270/p XDP pkt read, pkt_data <= pkt_meta', good access OK #1271/p XDP pkt read, pkt_data <= pkt_meta', bad access 1 OK #1272/p XDP pkt read, pkt_data <= pkt_meta', bad access 2 OK Summary: 1900 PASSED, 0 SKIPPED, 0 FAILED Acked-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpf, selftests: Add test case for atomic fetch on spilled pointerDaniel Borkmann2021-12-152-0/+117
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test whether unprivileged would be able to leak the spilled pointer either by exporting the returned value from the atomic{32,64} operation or by reading and exporting the value from the stack after the atomic operation took place. Note that for unprivileged, the below atomic cmpxchg test case named "Dest pointer in r0 - succeed" is failing. The reason is that in the dst memory location (r10 -8) there is the spilled register r10: 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 0: (bf) r0 = r10 1: R0_w=fp0 R1=ctx(id=0,off=0,imm=0) R10=fp0 1: (7b) *(u64 *)(r10 -8) = r0 2: R0_w=fp0 R1=ctx(id=0,off=0,imm=0) R10=fp0 fp-8_w=fp 2: (b7) r1 = 0 3: R0_w=fp0 R1_w=invP0 R10=fp0 fp-8_w=fp 3: (db) r0 = atomic64_cmpxchg((u64 *)(r10 -8), r0, r1) 4: R0_w=fp0 R1_w=invP0 R10=fp0 fp-8_w=mmmmmmmm 4: (79) r1 = *(u64 *)(r0 -8) 5: R0_w=fp0 R1_w=invP(id=0) R10=fp0 fp-8_w=mmmmmmmm 5: (b7) r0 = 0 6: R0_w=invP0 R1_w=invP(id=0) R10=fp0 fp-8_w=mmmmmmmm 6: (95) exit However, allowing this case for unprivileged is a bit useless given an update with a new pointer will fail anyway: 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 0: (bf) r0 = r10 1: R0_w=fp0 R1=ctx(id=0,off=0,imm=0) R10=fp0 1: (7b) *(u64 *)(r10 -8) = r0 2: R0_w=fp0 R1=ctx(id=0,off=0,imm=0) R10=fp0 fp-8_w=fp 2: (db) r0 = atomic64_cmpxchg((u64 *)(r10 -8), r0, r10) R10 leaks addr into mem Acked-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * selftests/bpf: Tests for state pruning with u32 spill/fillPaul Chaignon2021-12-102-0/+103
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds tests for the verifier's tracking for spilled, <8B registers. The first two test cases ensure the verifier doesn't incorrectly prune states in case of <8B spill/fills. The last one simply checks that a filled u64 register is marked unknown if the register spilled in the same slack slot was less than 8B. The map value access at the end of the first program is only incorrect for the path R6=32. If the precision bit for register R8 isn't backtracked through the u32 spill/fill, the R6=32 path is pruned at instruction 9 and the program is incorrectly accepted. The second program is a variation of the same with u32 spills and a u64 fill. The additional instructions to introduce the first pruning point may be a bit fragile as they depend on the heuristics for pruning points in the verifier (currently at least 8 instructions and 2 jumps). If the heuristics are changed, the pruning point may move (e.g., to the subsequent jump) or disappear, which would cause the test to always pass. Signed-off-by: Paul Chaignon <paul@isovalent.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-12-091-32/+600
|\| | | | | | | | | | | No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf: Add selftests to cover packet access corner casesMaxim Mikityanskiy2021-12-081-16/+584
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This commit adds BPF verifier selftests that cover all corner cases by packet boundary checks. Specifically, 8-byte packet reads are tested at the beginning of data and at the beginning of data_meta, using all kinds of boundary checks (all comparison operators: <, >, <=, >=; both permutations of operands: data + length compared to end, end compared to data + length). For each case there are three tests: 1. Length is just enough for an 8-byte read. Length is either 7 or 8, depending on the comparison. 2. Length is increased by 1 - should still pass the verifier. These cases are useful, because they failed before commit 2fa7d94afc1a ("bpf: Fix the off-by-two error in range markings"). 3. Length is decreased by 1 - should be rejected by the verifier. Some existing tests are just renamed to avoid duplication. Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211207081521.41923-1-maximmi@nvidia.com
| * bpf: Fix the off-by-two error in range markingsMaxim Mikityanskiy2021-12-031-16/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The first commit cited below attempts to fix the off-by-one error that appeared in some comparisons with an open range. Due to this error, arithmetically equivalent pieces of code could get different verdicts from the verifier, for example (pseudocode): // 1. Passes the verifier: if (data + 8 > data_end) return early read *(u64 *)data, i.e. [data; data+7] // 2. Rejected by the verifier (should still pass): if (data + 7 >= data_end) return early read *(u64 *)data, i.e. [data; data+7] The attempted fix, however, shifts the range by one in a wrong direction, so the bug not only remains, but also such piece of code starts failing in the verifier: // 3. Rejected by the verifier, but the check is stricter than in #1. if (data + 8 >= data_end) return early read *(u64 *)data, i.e. [data; data+7] The change performed by that fix converted an off-by-one bug into off-by-two. The second commit cited below added the BPF selftests written to ensure than code chunks like #3 are rejected, however, they should be accepted. This commit fixes the off-by-two error by adjusting new_range in the right direction and fixes the tests by changing the range into the one that should actually fail. Fixes: fb2a311a31d3 ("bpf: fix off by one for range markings with L{T, E} patterns") Fixes: b37242c773b2 ("bpf: add test cases to bpf selftests to cover all access tests") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211130181607.593149-1-maximmi@nvidia.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-11-182-0/+230
|\| | | | | | | Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * selftests/bpf: Add tests for restricted helpersDmitrii Banshchikov2021-11-161-0/+196
| | | | | | | | | | | | | | | | | | | | This patch adds tests that bpf_ktime_get_coarse_ns(), bpf_timer_* and bpf_spin_lock()/bpf_spin_unlock() helpers are forbidden in tracing progs as their use there may result in various locking issues. Signed-off-by: Dmitrii Banshchikov <me@ubique.spb.ru> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211113142227.566439-3-me@ubique.spb.ru
| * selftests/bpf: Check map in map pruningLorenz Bauer2021-11-131-0/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ensure that two registers with a map_value loaded from a nested map are considered equivalent for the purpose of state pruning and don't cause the verifier to revisit a pruning point. This uses a rather crude match on the number of insns visited by the verifier, which might change in the future. I've therefore tried to keep the code as "unpruneable" as possible by having the code paths only converge on the second to last instruction. Should you require to adjust the test in the future, reducing the number of processed instructions should always be safe. Increasing them could cause another regression, so proceed with caution. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/CACAyw99hVEJFoiBH_ZGyy=+oO-jyydoz6v1DeKPKs2HVsUH28w@mail.gmail.com Link: https://lore.kernel.org/bpf/20211111161452.86864-1-lmb@cloudflare.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | Merge https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextJakub Kicinski2021-11-151-0/+32
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2021-11-15 We've added 72 non-merge commits during the last 13 day(s) which contain a total of 171 files changed, 2728 insertions(+), 1143 deletions(-). The main changes are: 1) Add btf_type_tag attributes to bring kernel annotations like __user/__rcu to BTF such that BPF verifier will be able to detect misuse, from Yonghong Song. 2) Big batch of libbpf improvements including various fixes, future proofing APIs, and adding a unified, OPTS-based bpf_prog_load() low-level API, from Andrii Nakryiko. 3) Add ingress_ifindex to BPF_SK_LOOKUP program type for selectively applying the programmable socket lookup logic to packets from a given netdev, from Mark Pashmfouroush. 4) Remove the 128M upper JIT limit for BPF programs on arm64 and add selftest to ensure exception handling still works, from Russell King and Alan Maguire. 5) Add a new bpf_find_vma() helper for tracing to map an address to the backing file such as shared library, from Song Liu. 6) Batch of various misc fixes to bpftool, fixing a memory leak in BPF program dump, updating documentation and bash-completion among others, from Quentin Monnet. 7) Deprecate libbpf bpf_program__get_prog_info_linear() API and migrate its users as the API is heavily tailored around perf and is non-generic, from Dave Marchevsky. 8) Enable libbpf's strict mode by default in bpftool and add a --legacy option as an opt-out for more relaxed BPF program requirements, from Stanislav Fomichev. 9) Fix bpftool to use libbpf_get_error() to check for errors, from Hengqi Chen. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (72 commits) bpftool: Use libbpf_get_error() to check error bpftool: Fix mixed indentation in documentation bpftool: Update the lists of names for maps and prog-attach types bpftool: Fix indent in option lists in the documentation bpftool: Remove inclusion of utilities.mak from Makefiles bpftool: Fix memory leak in prog_dump() selftests/bpf: Fix a tautological-constant-out-of-range-compare compiler warning selftests/bpf: Fix an unused-but-set-variable compiler warning bpf: Introduce btf_tracing_ids bpf: Extend BTF_ID_LIST_GLOBAL with parameter for number of IDs bpftool: Enable libbpf's strict mode by default docs/bpf: Update documentation for BTF_KIND_TYPE_TAG support selftests/bpf: Clarify llvm dependency with btf_tag selftest selftests/bpf: Add a C test for btf_type_tag selftests/bpf: Rename progs/tag.c to progs/btf_decl_tag.c selftests/bpf: Test BTF_KIND_DECL_TAG for deduplication selftests/bpf: Add BTF_KIND_TYPE_TAG unit tests selftests/bpf: Test libbpf API function btf__add_type_tag() bpftool: Support BTF_KIND_TYPE_TAG libbpf: Support BTF_KIND_TYPE_TAG ... ==================== Link: https://lore.kernel.org/r/20211115162008.25916-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * selftests/bpf: Add tests for accessing ingress_ifindex in bpf_sk_lookupMark Pashmfouroush2021-11-111-0/+32
| | | | | | | | | | | | | | | | | | | | A new field was added to the bpf_sk_lookup data that users can access. Add tests that validate that the new ingress_ifindex field contains the right data. Signed-off-by: Mark Pashmfouroush <markpash@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211110111016.5670-3-markpash@cloudflare.com
* | selftests/bpf: Verifier test on refill from a smaller spillMartin KaFai Lau2021-11-031-0/+17
|/ | | | | | | | | | | | | This patch adds a verifier test to ensure the verifier can read 8 bytes from the stack after two 32bit write at fp-4 and fp-8. The test is similar to the reported case from bcc [0]. [0] https://github.com/iovisor/bcc/pull/3683 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211102064541.316414-1-kafai@fb.com
* bpf: Fix propagation of bounds from 64-bit min/max into 32-bit and var_off.Alexei Starovoitov2021-11-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Before this fix: 166: (b5) if r2 <= 0x1 goto pc+22 from 166 to 189: R2=invP(id=1,umax_value=1,var_off=(0x0; 0xffffffff)) After this fix: 166: (b5) if r2 <= 0x1 goto pc+22 from 166 to 189: R2=invP(id=1,umax_value=1,var_off=(0x0; 0x1)) While processing BPF_JLE the reg_set_min_max() would set true_reg->umax_value = 1 and call __reg_combine_64_into_32(true_reg). Without the fix it would not pass the condition: if (__reg64_bound_u32(reg->umin_value) && __reg64_bound_u32(reg->umax_value)) since umin_value == 0 at this point. Before commit 10bf4e83167c the umin was incorrectly ingored. The commit 10bf4e83167c fixed the correctness issue, but pessimized propagation of 64-bit min max into 32-bit min max and corresponding var_off. Fixes: 10bf4e83167c ("bpf: Fix propagation of 32 bit unsigned bounds from 64 bit bounds") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20211101222153.78759-1-alexei.starovoitov@gmail.com
* selftests/bpf: Use __BYTE_ORDER__Ilya Leoshkevich2021-10-263-11/+11
| | | | | | | | | Use the compiler-defined __BYTE_ORDER__ instead of the libc-defined __BYTE_ORDER for consistency. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211026010831.748682-4-iii@linux.ibm.com
* selftests/bpf: Some more atomic testsBrendan Jackman2021-10-213-0/+120
| | | | | | | | | | | | Some new verifier tests that hit some important gaps in the parameter space for atomic ops. There are already exhaustive tests for the JIT part in lib/test_bpf.c, but these exercise the verifier too. Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211015093318.1273686-1-jackmanb@google.com
* bpf, x64: Save bytes for DIV by reducing reg copiesJie Meng2021-10-061-0/+47
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of unconditionally performing push/pop on %rax/%rdx in case of division/modulo, we can save a few bytes in case of destination register being either BPF r0 (%rax) or r3 (%rdx) since the result is written in there anyway. Also, we do not need to copy the source to %r11 unless the source is either %rax, %rdx or an immediate. For example, before the patch: 22: push %rax 23: push %rdx 24: mov %rsi,%r11 27: xor %edx,%edx 29: div %r11 2c: mov %rax,%r11 2f: pop %rdx 30: pop %rax 31: mov %r11,%rax After: 22: push %rdx 23: xor %edx,%edx 25: div %rsi 28: pop %rdx Signed-off-by: Jie Meng <jmeng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211002035626.2041910-1-jmeng@fb.com
* bpf: selftests: Add selftests for module kfunc supportKumar Kartikeya Dwivedi2021-10-061-0/+23
| | | | | | | | | | | | | | | This adds selftests that tests the success and failure path for modules kfuncs (in presence of invalid kfunc calls) for both libbpf and gen_loader. It also adds a prog_test kfunc_btf_id_list so that we can add module BTF ID set from bpf_testmod. This also introduces a couple of test cases to verifier selftests for validating whether we get an error or not depending on if invalid kfunc call remains after elimination of unreachable instructions. Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211002011757.311265-10-memxor@gmail.com
* bpf: selftest: Add verifier tests for <8-byte scalar spill and refillMartin KaFai Lau2021-09-261-0/+161
| | | | | | | | This patch adds a few verifier tests for <8-byte spill and refill. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210922004953.627183-1-kafai@fb.com
* bpf,x64 Emit IMUL instead of MUL for x86-64Jie Meng2021-09-151-3/+19
| | | | | | | | | | | IMUL allows for multiple operands and saving and storing rax/rdx is no longer needed. Signedness of the operands doesn't matter here because the we only keep the lower 32/64 bit of the product for 32/64 bit multiplications. Signed-off-by: Jie Meng <jmeng@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210913211337.1564014-1-jmeng@fb.com
* selftests/bpf: Test new __sk_buff field hwtstampVadim Fedorenko2021-09-101-0/+60
| | | | | | | | | | Analogous to the gso_segs selftests introduced in commit d9ff286a0f59 ("bpf: allow BPF programs access skb_shared_info->gso_segs field"). Signed-off-by: Vadim Fedorenko <vfedorenko@novek.ru> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20210909220409.8804-3-vfedorenko@novek.ru
* selftests, bpf: Test that dead ldx_w insns are acceptedIlya Leoshkevich2021-08-131-0/+12
| | | | | | | | | Prevent regressions related to zero-extension metadata handling during dead code sanitization. Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210812151811.184086-3-iii@linux.ibm.com
* bpf, selftests: Add test cases for pointer alu from multiple pathsDaniel Borkmann2021-07-161-0/+229
| | | | | | | | | | | | | | | | | | | | | | | | | | | Add several test cases for checking update_alu_sanitation_state() under multiple paths: # ./test_verifier [...] #1061/u map access: known scalar += value_ptr unknown vs const OK #1061/p map access: known scalar += value_ptr unknown vs const OK #1062/u map access: known scalar += value_ptr const vs unknown OK #1062/p map access: known scalar += value_ptr const vs unknown OK #1063/u map access: known scalar += value_ptr const vs const (ne) OK #1063/p map access: known scalar += value_ptr const vs const (ne) OK #1064/u map access: known scalar += value_ptr const vs const (eq) OK #1064/p map access: known scalar += value_ptr const vs const (eq) OK #1065/u map access: known scalar += value_ptr unknown vs unknown (eq) OK #1065/p map access: known scalar += value_ptr unknown vs unknown (eq) OK #1066/u map access: known scalar += value_ptr unknown vs unknown (lt) OK #1066/p map access: known scalar += value_ptr unknown vs unknown (lt) OK #1067/u map access: known scalar += value_ptr unknown vs unknown (gt) OK #1067/p map access: known scalar += value_ptr unknown vs unknown (gt) OK [...] Summary: 1762 PASSED, 0 SKIPPED, 0 FAILED Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org>
* bpf, selftests: Adjust few selftest outcomes wrt unreachable codeDaniel Borkmann2021-06-147-7/+52
| | | | | | | | | | | | | | | | | | | | | In almost all cases from test_verifier that have been changed in here, we've had an unreachable path with a load from a register which has an invalid address on purpose. This was basically to make sure that we never walk this path and to have the verifier complain if it would otherwise. Change it to match on the right error for unprivileged given we now test these paths under speculative execution. There's one case where we match on exact # of insns_processed. Due to the extra path, this will of course mismatch on unprivileged. Thus, restrict the test->insn_processed check to privileged-only. In one other case, we result in a 'pointer comparison prohibited' error. This is similarly due to verifying an 'invalid' branch where we end up with a value pointer on one side of the comparison. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* bpf, selftests: Adjust few selftest result_unpriv outcomesDaniel Borkmann2021-05-252-10/+0
| | | | | | | | | Given we don't need to simulate the speculative domain for registers with immediates anymore since the verifier uses direct imm-based rewrites instead of having to mask, we can also lift a few cases that were previously rejected. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org>
* bpf: Fix propagation of 32 bit unsigned bounds from 64 bit boundsDaniel Borkmann2021-04-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similarly as b02709587ea3 ("bpf: Fix propagation of 32-bit signed bounds from 64-bit bounds."), we also need to fix the propagation of 32 bit unsigned bounds from 64 bit counterparts. That is, really only set the u32_{min,max}_value when /both/ {umin,umax}_value safely fit in 32 bit space. For example, the register with a umin_value == 1 does /not/ imply that u32_min_value is also equal to 1, since umax_value could be much larger than 32 bit subregister can hold, and thus u32_min_value is in the interval [0,1] instead. Before fix, invalid tracking result of R2_w=inv1: [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smin_value=-9223372036854775807,smax_value=9223372032559808513,umin_value=1,umax_value=18446744069414584321,var_off=(0x1; 0xffffffff00000000),s32_min_value=1,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv1 R10=fp0 [...] After fix, correct tracking result of R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)): [...] 5: R0_w=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0) R10=fp0 5: (35) if r2 >= 0x1 goto pc+1 [...] // goto path 7: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,umin_value=1) R10=fp0 7: (b6) if w2 <= 0x1 goto pc+1 [...] // goto path 9: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2=inv(id=0,smax_value=9223372032559808513,umax_value=18446744069414584321,var_off=(0x0; 0xffffffff00000001),s32_min_value=0,s32_max_value=1,u32_max_value=1) R10=fp0 9: (bc) w2 = w2 10: R0=inv1337 R1=ctx(id=0,off=0,imm=0) R2_w=inv(id=0,umax_value=1,var_off=(0x0; 0x1)) R10=fp0 [...] Thus, same issue as in b02709587ea3 holds for unsigned subregister tracking. Also, align __reg64_bound_u32() similarly to __reg64_bound_s32() as done in b02709587ea3 to make them uniform again. Fixes: 3f50f132d840 ("bpf: Verifier, do explicit ALU32 bounds tracking") Reported-by: Manfred Paul (@_manfp) Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2021-04-261-0/+43
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-04-23 The following pull-request contains BPF updates for your *net-next* tree. We've added 69 non-merge commits during the last 22 day(s) which contain a total of 69 files changed, 3141 insertions(+), 866 deletions(-). The main changes are: 1) Add BPF static linker support for extern resolution of global, from Andrii. 2) Refine retval for bpf_get_task_stack helper, from Dave. 3) Add a bpf_snprintf helper, from Florent. 4) A bunch of miscellaneous improvements from many developers. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf/selftests: Add bpf_get_task_stack retval bounds verifier testDave Marchevsky2021-04-201-0/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a bpf_iter test which feeds bpf_get_task_stack's return value into seq_write after confirming it's positive. No attempt to bound the value from above is made. Load will fail if verifier does not refine retval range based on buf sz input to bpf_get_task_stack. Signed-off-by: Dave Marchevsky <davemarchevsky@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Song Liu <songliubraving@fb.com> Link: https://lore.kernel.org/bpf/20210416204704.2816874-3-davemarchevsky@fb.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski2021-04-176-35/+16
|\ \ | |/ |/| | | | | | | | | | | | | drivers/net/ethernet/stmicro/stmmac/stmmac_main.c - keep the ZC code, drop the code related to reinit net/bridge/netfilter/ebtables.c - fix build after move to net_generic Signed-off-by: Jakub Kicinski <kuba@kernel.org>
| * bpf: Update selftests to reflect new error statesDaniel Borkmann2021-04-166-35/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Update various selftest error messages: * The 'Rx tried to sub from different maps, paths, or prohibited types' is reworked into more specific/differentiated error messages for better guidance. * The change into 'value -4294967168 makes map_value pointer be out of bounds' is due to moving the mixed bounds check into the speculation handling and thus occuring slightly later than above mentioned sanity check. * The change into 'math between map_value pointer and register with unbounded min value' is similarly due to register sanity check coming before the mixed bounds check. * The case of 'map access: known scalar += value_ptr from different maps' now loads fine given masks are the same from the different paths (despite max map value size being different). Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Alexei Starovoitov <ast@kernel.org>
* | bpf: Support bpf program calling kernel functionMartin KaFai Lau2021-03-272-11/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds support to BPF verifier to allow bpf program calling kernel function directly. The use case included in this set is to allow bpf-tcp-cc to directly call some tcp-cc helper functions (e.g. "tcp_cong_avoid_ai()"). Those functions have already been used by some kernel tcp-cc implementations. This set will also allow the bpf-tcp-cc program to directly call the kernel tcp-cc implementation, For example, a bpf_dctcp may only want to implement its own dctcp_cwnd_event() and reuse other dctcp_*() directly from the kernel tcp_dctcp.c instead of reimplementing (or copy-and-pasting) them. The tcp-cc kernel functions mentioned above will be white listed for the struct_ops bpf-tcp-cc programs to use in a later patch. The white listed functions are not bounded to a fixed ABI contract. Those functions have already been used by the existing kernel tcp-cc. If any of them has changed, both in-tree and out-of-tree kernel tcp-cc implementations have to be changed. The same goes for the struct_ops bpf-tcp-cc programs which have to be adjusted accordingly. This patch is to make the required changes in the bpf verifier. First change is in btf.c, it adds a case in "btf_check_func_arg_match()". When the passed in "btf->kernel_btf == true", it means matching the verifier regs' states with a kernel function. This will handle the PTR_TO_BTF_ID reg. It also maps PTR_TO_SOCK_COMMON, PTR_TO_SOCKET, and PTR_TO_TCP_SOCK to its kernel's btf_id. In the later libbpf patch, the insn calling a kernel function will look like: insn->code == (BPF_JMP | BPF_CALL) insn->src_reg == BPF_PSEUDO_KFUNC_CALL /* <- new in this patch */ insn->imm == func_btf_id /* btf_id of the running kernel */ [ For the future calling function-in-kernel-module support, an array of module btf_fds can be passed at the load time and insn->off can be used to index into this array. ] At the early stage of verifier, the verifier will collect all kernel function calls into "struct bpf_kfunc_desc". Those descriptors are stored in "prog->aux->kfunc_tab" and will be available to the JIT. Since this "add" operation is similar to the current "add_subprog()" and looking for the same insn->code, they are done together in the new "add_subprog_and_kfunc()". In the "do_check()" stage, the new "check_kfunc_call()" is added to verify the kernel function call instruction: 1. Ensure the kernel function can be used by a particular BPF_PROG_TYPE. A new bpf_verifier_ops "check_kfunc_call" is added to do that. The bpf-tcp-cc struct_ops program will implement this function in a later patch. 2. Call "btf_check_kfunc_args_match()" to ensure the regs can be used as the args of a kernel function. 3. Mark the regs' type, subreg_def, and zext_dst. At the later do_misc_fixups() stage, the new fixup_kfunc_call() will replace the insn->imm with the function address (relative to __bpf_call_base). If needed, the jit can find the btf_func_model by calling the new bpf_jit_find_kfunc_model(prog, insn). With the imm set to the function address, "bpftool prog dump xlated" will be able to display the kernel function calls the same way as it displays other bpf helper calls. gpl_compatible program is required to call kernel function. This feature currently requires JIT. The verifier selftests are adjusted because of the changes in the verbose log in add_subprog_and_kfunc(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210325015142.1544736-1-kafai@fb.com
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller2021-03-254-10/+59
|\| | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpf, selftests: Fix up some test_verifier cases for unprivilegedPiotr Krysiuk2021-03-174-10/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix up test_verifier error messages for the case where the original error message changed, or for the case where pointer alu errors differ between privileged and unprivileged tests. Also, add alternative tests for keeping coverage of the original verifier rejection error message (fp alu), and newly reject map_ptr += rX where rX == 0 given we now forbid alu on these types for unprivileged. All test_verifier cases pass after the change. The test case fixups were kept separate to ease backporting of core changes. Signed-off-by: Piotr Krysiuk <piotras@gmail.com> Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org>
* | Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2021-03-101-0/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf-next 2021-03-09 The following pull-request contains BPF updates for your *net-next* tree. We've added 90 non-merge commits during the last 17 day(s) which contain a total of 114 files changed, 5158 insertions(+), 1288 deletions(-). The main changes are: 1) Faster bpf_redirect_map(), from Björn. 2) skmsg cleanup, from Cong. 3) Support for floating point types in BTF, from Ilya. 4) Documentation for sys_bpf commands, from Joe. 5) Support for sk_lookup in bpf_prog_test_run, form Lorenz. 6) Enable task local storage for tracing programs, from Song. 7) bpf_for_each_map_elem() helper, from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * selftests: bpf: Don't run sk_lookup in verifier testsLorenz Bauer2021-03-051-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | sk_lookup doesn't allow setting data_in for bpf_prog_run. This doesn't play well with the verifier tests, since they always set a 64 byte input buffer. Allow not running verifier tests by setting bpf_test.runs to a negative value and don't run the ctx access case for sk_lookup. We have dedicated ctx access tests so skipping here doesn't reduce coverage. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210303101816.36774-6-lmb@cloudflare.com
* | bpf: Explicitly zero-extend R0 after 32-bit cmpxchgBrendan Jackman2021-03-052-0/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As pointed out by Ilya and explained in the new comment, there's a discrepancy between x86 and BPF CMPXCHG semantics: BPF always loads the value from memory into r0, while x86 only does so when r0 and the value in memory are different. The same issue affects s390. At first this might sound like pure semantics, but it makes a real difference when the comparison is 32-bit, since the load will zero-extend r0/rax. The fix is to explicitly zero-extend rax after doing such a CMPXCHG. Since this problem affects multiple archs, this is done in the verifier by patching in a BPF_ZEXT_REG instruction after every 32-bit cmpxchg. Any archs that don't need such manual zero-extension can do a look-ahead with insn_is_zext to skip the unnecessary mov. Note this still goes on top of Ilya's patch: https://lore.kernel.org/bpf/20210301154019.129110-1-iii@linux.ibm.com/T/#u Differences v5->v6[1]: - Moved is_cmpxchg_insn and ensured it can be safely re-used. Also renamed it and removed 'inline' to match the style of the is_*_function helpers. - Fixed up comments in verifier test (thanks for the careful review, Martin!) Differences v4->v5[1]: - Moved the logic entirely into opt_subreg_zext_lo32_rnd_hi32, thanks to Martin for suggesting this. Differences v3->v4[1]: - Moved the optimization against pointless zext into the correct place: opt_subreg_zext_lo32_rnd_hi32 is called _after_ fixup_bpf_calls. Differences v2->v3[1]: - Moved patching into fixup_bpf_calls (patch incoming to rename this function) - Added extra commentary on bpf_jit_needs_zext - Added check to avoid adding a pointless zext(r0) if there's already one there. Difference v1->v2[1]: Now solved centrally in the verifier instead of specifically for the x86 JIT. Thanks to Ilya and Daniel for the suggestions! [1] v5: https://lore.kernel.org/bpf/CA+i-1C3ytZz6FjcPmUg5s4L51pMQDxWcZNvM86w4RHZ_o2khwg@mail.gmail.com/T/#t v4: https://lore.kernel.org/bpf/CA+i-1C3ytZz6FjcPmUg5s4L51pMQDxWcZNvM86w4RHZ_o2khwg@mail.gmail.com/T/#t v3: https://lore.kernel.org/bpf/08669818-c99d-0d30-e1db-53160c063611@iogearbox.net/T/#t v2: https://lore.kernel.org/bpf/08669818-c99d-0d30-e1db-53160c063611@iogearbox.net/T/#t v1: https://lore.kernel.org/bpf/d7ebaefb-bfd6-a441-3ff2-2fdfe699b1d2@iogearbox.net/T/#t Reported-by: Ilya Leoshkevich <iii@linux.ibm.com> Fixes: 5ffa25502b5a ("bpf: Add instructions for atomic_[cmp]xchg") Signed-off-by: Brendan Jackman <jackmanb@google.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Ilya Leoshkevich <iii@linux.ibm.com> Tested-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* | selftests/bpf: Mask bpf_csum_diff() return value to 16 bits in test_verifierYauheni Kaliuta2021-03-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The verifier test labelled "valid read map access into a read-only array 2" calls the bpf_csum_diff() helper and checks its return value. However, architecture implementations of csum_partial() (which is what the helper uses) differ in whether they fold the return value to 16 bit or not. For example, x86 version has ... if (unlikely(odd)) { result = from32to16(result); result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); } ... while generic lib/checksum.c does: result = from32to16(result); if (odd) result = ((result >> 8) & 0xff) | ((result & 0xff) << 8); This makes the helper return different values on different architectures, breaking the test on non-x86. To fix this, add an additional instruction to always mask the return value to 16 bits, and update the expected return value accordingly. Fixes: fb2abb73e575 ("bpf, selftest: test {rd, wr}only flags and direct value access") Signed-off-by: Yauheni Kaliuta <yauheni.kaliuta@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20210228103017.320240-1-yauheni.kaliuta@redhat.com
* | bpf, x86: Fix BPF_FETCH atomic and/or/xor with r0 as srcBrendan Jackman2021-02-221-0/+23
|/ | | | | | | | | | | | | | | | | | | | | This code generates a CMPXCHG loop in order to implement atomic_fetch bitwise operations. Because CMPXCHG is hard-coded to use rax (which holds the BPF r0 value), it saves the _real_ r0 value into the internal "ax" temporary register and restores it once the loop is complete. In the middle of the loop, the actual bitwise operation is performed using src_reg. The bug occurs when src_reg is r0: as described above, r0 has been clobbered and the real r0 value is in the ax register. Therefore, perform this operation on the ax register instead, when src_reg is r0. Fixes: 981f94c3e921 ("bpf: Add bitwise atomic instructions") Signed-off-by: Brendan Jackman <jackmanb@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: KP Singh <kpsingh@kernel.org> Link: https://lore.kernel.org/bpf/20210216125307.1406237-1-jackmanb@google.com
* selftests/bpf: Fix endianness issues in atomic testsIlya Leoshkevich2021-02-103-3/+3
| | | | | | | | | | | | Atomic tests store a DW, but then load it back as a W from the same address. This doesn't work on big-endian systems, and since the point of those tests is not testing narrow loads, fix simply by loading a DW. Fixes: 98d666d05a1d ("bpf: Add tests for new BPF atomic operations") Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20210210020713.77911-1-iii@linux.ibm.com
* selftest/bpf: Verifier tests for var-off accessAndrei Matei2021-02-101-2/+97
| | | | | | | | | Add tests for the new functionality - reading and writing to the stack through a variable-offset pointer. Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-4-andreimatei1@gmail.com
* selftest/bpf: Adjust expected verifier errorsAndrei Matei2021-02-109-37/+41
| | | | | | | | | The verifier errors around stack accesses have changed slightly in the previous commit (generally for the better). Signed-off-by: Andrei Matei <andreimatei1@gmail.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20210207011027.676572-3-andreimatei1@gmail.com
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