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* selftests/bpf: Implement sample tcp/tcp6 bpf_iter programsYonghong Song2020-06-243-0/+499
| | | | | | | | | | | | | | | | | | | | | | | | | | In my VM, I got identical result compared to /proc/net/{tcp,tcp6}. For tcp6: $ cat /proc/net/tcp6 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000000000000000000000000000:0016 00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000001 00000000 0 0 17955 1 000000003eb3102e 100 0 0 10 0 $ cat /sys/fs/bpf/p1 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000000000000000000000000000:0016 00000000000000000000000000000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 17955 1 000000003eb3102e 100 0 0 10 0 For tcp: $ cat /proc/net/tcp sl local_address rem_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 0: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 2666 1 000000007152e43f 100 0 0 10 0 $ cat /sys/fs/bpf/p2 sl local_address remote_address st tx_queue rx_queue tr tm->when retrnsmt uid timeout inode 1: 00000000:0016 00000000:0000 0A 00000000:00000000 00:00000000 00000000 0 0 2666 1 000000007152e43f 100 0 0 10 0 Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230820.3989165-1-yhs@fb.com
* selftests/bpf: Add more common macros to bpf_tracing_net.hYonghong Song2020-06-241-0/+35
| | | | | | | | | | | These newly added macros will be used in subsequent bpf iterator tcp{4,6} and udp{4,6} programs. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230819.3989050-1-yhs@fb.com
* selftests/bpf: Refactor some net macros to bpf_tracing_net.hYonghong Song2020-06-243-9/+18
| | | | | | | | | | | | | | | Refactor bpf_iter_ipv6_route.c and bpf_iter_netlink.c so net macros, originally from various include/linux header files, are moved to a new header file bpf_tracing_net.h. The goal is to improve reuse so networking tracing programs do not need to copy these macros every time they use them. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230817.3988962-1-yhs@fb.com
* selftests/bpf: Move newer bpf_iter_* type redefining to a new header fileYonghong Song2020-06-249-136/+57
| | | | | | | | | | | | | | | | | | | | Commit b9f4c01f3e0b ("selftest/bpf: Make bpf_iter selftest compilable against old vmlinux.h") and Commit dda18a5c0b75 ("selftests/bpf: Convert bpf_iter_test_kern{3, 4}.c to define own bpf_iter_meta") redefined newly introduced types in bpf programs so the bpf program can still compile properly with old kernels although loading may fail. Since this patch set introduced new types and the same workaround is needed, so let us move the workaround to a separate header file so they do not clutter bpf programs. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230816.3988656-1-yhs@fb.com
* bpf: Add bpf_skc_to_udp6_sock() helperYonghong Song2020-06-241-1/+8
| | | | | | | | | | | | The helper is used in tracing programs to cast a socket pointer to a udp6_sock pointer. The return value could be NULL if the casting is illegal. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: Eric Dumazet <edumazet@google.com> Link: https://lore.kernel.org/bpf/20200623230815.3988481-1-yhs@fb.com
* bpf: Add bpf_skc_to_{tcp, tcp_timewait, tcp_request}_sock() helpersYonghong Song2020-06-241-1/+22
| | | | | | | | | | | Three more helpers are added to cast a sock_common pointer to an tcp_sock, tcp_timewait_sock or a tcp_request_sock for tracing programs. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230811.3988277-1-yhs@fb.com
* bpf: Add bpf_skc_to_tcp6_sock() helperYonghong Song2020-06-241-1/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | The helper is used in tracing programs to cast a socket pointer to a tcp6_sock pointer. The return value could be NULL if the casting is illegal. A new helper return type RET_PTR_TO_BTF_ID_OR_NULL is added so the verifier is able to deduce proper return types for the helper. Different from the previous BTF_ID based helpers, the bpf_skc_to_tcp6_sock() argument can be several possible btf_ids. More specifically, all possible socket data structures with sock_common appearing in the first in the memory layout. This patch only added socket types related to tcp and udp. All possible argument btf_id and return value btf_id for helper bpf_skc_to_tcp6_sock() are pre-calculcated and cached. In the future, it is even possible to precompute these btf_id's at kernel build time. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200623230809.3988195-1-yhs@fb.com
* bpf: Add SO_KEEPALIVE and related options to bpf_setsockoptDmitry Yakunin2020-06-242-2/+32
| | | | | | | | | | | | | | | | | | This patch adds support of SO_KEEPALIVE flag and TCP related options to bpf_setsockopt() routine. This is helpful if we want to enable or tune TCP keepalive for applications which don't do it in the userspace code. v3: - update kernel-doc in uapi (Nikita Vetoshkin <nekto0n@yandex-team.ru>) v4: - update kernel-doc in tools too (Alexei Starovoitov) - add test to selftests (Alexei Starovoitov) Signed-off-by: Dmitry Yakunin <zeil@yandex-team.ru> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20200620153052.9439-3-zeil@yandex-team.ru
* selftests/bpf: Workaround for get_stack_rawtp test.Alexei Starovoitov2020-06-241-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ./test_progs-no_alu32 -t get_stack_raw_tp fails due to: 52: (85) call bpf_get_stack#67 53: (bf) r8 = r0 54: (bf) r1 = r8 55: (67) r1 <<= 32 56: (c7) r1 s>>= 32 ; if (usize < 0) 57: (c5) if r1 s< 0x0 goto pc+26 R0=inv(id=0,smax_value=800) R1_w=inv(id=0,umax_value=800,var_off=(0x0; 0x3ff)) R6=ctx(id=0,off=0,imm=0) R7=map_value(id=0,off=0,ks=4,vs=1600,imm=0) R8_w=inv(id=0,smax_value=800) R9=inv800 ; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); 58: (1f) r9 -= r8 ; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); 59: (bf) r2 = r7 60: (0f) r2 += r1 regs=1 stack=0 before 52: (85) call bpf_get_stack#67 ; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); 61: (bf) r1 = r6 62: (bf) r3 = r9 63: (b7) r4 = 0 64: (85) call bpf_get_stack#67 R0=inv(id=0,smax_value=800) R1_w=ctx(id=0,off=0,imm=0) R2_w=map_value(id=0,off=0,ks=4,vs=1600,umax_value=800,var_off=(0x0; 0x3ff),s32_max_value=1023,u32_max_value=1023) R3_w=inv(id=0,umax_value=9223372036854776608) R3 unbounded memory access, use 'var &= const' or 'if (var < const)' In the C code: usize = bpf_get_stack(ctx, raw_data, max_len, BPF_F_USER_STACK); if (usize < 0) return 0; ksize = bpf_get_stack(ctx, raw_data + usize, max_len - usize, 0); if (ksize < 0) return 0; We used to have problem with pointer arith in R2. Now it's a problem with two integers in R3. 'if (usize < 0)' is comparing R1 and makes it [0,800], but R8 stays [-inf,800]. Both registers represent the same 'usize' variable. Then R9 -= R8 is doing 800 - [-inf, 800] so the result of "max_len - usize" looks unbounded to the verifier while it's obvious in C code that "max_len - usize" should be [0, 800]. To workaround the problem convert ksize and usize variables from int to long. Signed-off-by: Alexei Starovoitov <ast@kernel.org>
* libbpf: Prevent loading vmlinux BTF twiceAndrii Nakryiko2020-06-241-11/+22
| | | | | | | | | | Prevent loading/parsing vmlinux BTF twice in some cases: for CO-RE relocations and for BTF-aware hooks (tp_btf, fentry/fexit, etc). Fixes: a6ed02cac690 ("libbpf: Load btf_vmlinux only once per object.") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200624043805.1794620-1-andriin@fb.com
* libbpf: Fix spelling mistake "kallasyms" -> "kallsyms"Colin Ian King2020-06-241-1/+1
| | | | | | | | | There is a spelling mistake in a pr_warn message. Fix it. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200623084207.149253-1-colin.king@canonical.com
* tools, bpftool: Fix variable shadowing in emit_obj_refs_json()Quentin Monnet2020-06-241-8/+9
| | | | | | | | | | | | | | | | | | | | | | | Building bpftool yields the following complaint: pids.c: In function 'emit_obj_refs_json': pids.c:175:80: warning: declaration of 'json_wtr' shadows a global declaration [-Wshadow] 175 | void emit_obj_refs_json(struct obj_refs_table *table, __u32 id, json_writer_t *json_wtr) | ~~~~~~~~~~~~~~~^~~~~~~~ In file included from pids.c:11: main.h:141:23: note: shadowed declaration is here 141 | extern json_writer_t *json_wtr; | ^~~~~~~~ Let's rename the variable. v2: - Rename the variable instead of calling the global json_wtr directly. Signed-off-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200623213600.16643-1-quentin@isovalent.com
* Merge up to bpf_probe_read_kernel_str() fix into bpf-nextAlexei Starovoitov2020-06-232-1/+2
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| * tools/bpftool: Add ringbuf map to a list of known map typesAndrii Nakryiko2020-06-161-0/+1
| | | | | | | | | | | | | | | | | | Add symbolic name "ringbuf" to map to BPF_MAP_TYPE_RINGBUF. Without this, users will see "type 27" instead of "ringbuf" in `map show` output. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200615225355.366256-1-andriin@fb.com
| * bpf: Fix definition of bpf_ringbuf_output() helper in UAPI commentsAndrii Nakryiko2020-06-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | Fix definition of bpf_ringbuf_output() in UAPI header comments, which is used to generate libbpf's bpf_helper_defs.h header. Return value is a number (error code), not a pointer. Fixes: 457f44363a88 ("bpf: Implement BPF ring buffer and verifier support for it") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200615214926.3638836-1-andriin@fb.com
* | tools, bpftool: Correctly evaluate $(BUILD_BPF_SKELS) in MakefileTobias Klauser2020-06-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, if the clang-bpf-co-re feature is not available, the build fails with e.g. CC prog.o prog.c:1462:10: fatal error: profiler.skel.h: No such file or directory 1462 | #include "profiler.skel.h" | ^~~~~~~~~~~~~~~~~ This is due to the fact that the BPFTOOL_WITHOUT_SKELETONS macro is not defined, despite BUILD_BPF_SKELS not being set. Fix this by correctly evaluating $(BUILD_BPF_SKELS) when deciding on whether to add -DBPFTOOL_WITHOUT_SKELETONS to CFLAGS. Fixes: 05aca6da3b5a ("tools/bpftool: Generalize BPF skeleton support and generate vmlinux.h") Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200623103710.10370-1-tklauser@distanz.ch
* | selftests/bpf: Add variable-length data concat pattern less than testJohn Fastabend2020-06-242-4/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend original variable-length tests with a case to catch a common existing pattern of testing for < 0 for errors. Note because verifier also tracks upper bounds and we know it can not be greater than MAX_LEN here we can skip upper bound check. In ALU64 enabled compilation converting from long->int return types in probe helpers results in extra instruction pattern, <<= 32, s >>= 32. The trade-off is the non-ALU64 case works. If you really care about every extra insn (XDP case?) then you probably should be using original int type. In addition adding a sext insn to bpf might help the verifier in the general case to avoid these types of tricks. Signed-off-by: John Fastabend <john.fastabend@gmail.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200623032224.4020118-3-andriin@fb.com
* | selftests/bpf: Add variable-length data concatenation pattern testAndrii Nakryiko2020-06-242-0/+152
| | | | | | | | | | | | | | | | | | | | | | | | Add selftest that validates variable-length data reading and concatentation with one big shared data array. This is a common pattern in production use for monitoring and tracing applications, that potentially can read a lot of data, but overall read much less. Such pattern allows to determine precisely what amount of data needs to be sent over perfbuf/ringbuf and maximize efficiency. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200623032224.4020118-2-andriin@fb.com
* | bpf: Switch most helper return values from 32-bit int to 64-bit longAndrii Nakryiko2020-06-241-96/+96
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Switch most of BPF helper definitions from returning int to long. These definitions are coming from comments in BPF UAPI header and are used to generate bpf_helper_defs.h (under libbpf) to be later included and used from BPF programs. In actual in-kernel implementation, all the helpers are defined as returning u64, but due to some historical reasons, most of them are actually defined as returning int in UAPI (usually, to return 0 on success, and negative value on error). This actually causes Clang to quite often generate sub-optimal code, because compiler believes that return value is 32-bit, and in a lot of cases has to be up-converted (usually with a pair of 32-bit bit shifts) to 64-bit values, before they can be used further in BPF code. Besides just "polluting" the code, these 32-bit shifts quite often cause problems for cases in which return value matters. This is especially the case for the family of bpf_probe_read_str() functions. There are few other similar helpers (e.g., bpf_read_branch_records()), in which return value is used by BPF program logic to record variable-length data and process it. For such cases, BPF program logic carefully manages offsets within some array or map to read variable-length data. For such uses, it's crucial for BPF verifier to track possible range of register values to prove that all the accesses happen within given memory bounds. Those extraneous zero-extending bit shifts, inserted by Clang (and quite often interleaved with other code, which makes the issues even more challenging and sometimes requires employing extra per-variable compiler barriers), throws off verifier logic and makes it mark registers as having unknown variable offset. We'll study this pattern a bit later below. Another common pattern is to check return of BPF helper for non-zero state to detect error conditions and attempt alternative actions in such case. Even in this simple and straightforward case, this 32-bit vs BPF's native 64-bit mode quite often leads to sub-optimal and unnecessary extra code. We'll look at this pattern as well. Clang's BPF target supports two modes of code generation: ALU32, in which it is capable of using lower 32-bit parts of registers, and no-ALU32, in which only full 64-bit registers are being used. ALU32 mode somewhat mitigates the above described problems, but not in all cases. This patch switches all the cases in which BPF helpers return 0 or negative error from returning int to returning long. It is shown below that such change in definition leads to equivalent or better code. No-ALU32 mode benefits more, but ALU32 mode doesn't degrade or still gets improved code generation. Another class of cases switched from int to long are bpf_probe_read_str()-like helpers, which encode successful case as non-negative values, while still returning negative value for errors. In all of such cases, correctness is preserved due to two's complement encoding of negative values and the fact that all helpers return values with 32-bit absolute value. Two's complement ensures that for negative values higher 32 bits are all ones and when truncated, leave valid negative 32-bit value with the same value. Non-negative values have upper 32 bits set to zero and similarly preserve value when high 32 bits are truncated. This means that just casting to int/u32 is correct and efficient (and in ALU32 mode doesn't require any extra shifts). To minimize the chances of regressions, two code patterns were investigated, as mentioned above. For both patterns, BPF assembly was analyzed in ALU32/NO-ALU32 compiler modes, both with current 32-bit int return type and new 64-bit long return type. Case 1. Variable-length data reading and concatenation. This is quite ubiquitous pattern in tracing/monitoring applications, reading data like process's environment variables, file path, etc. In such case, many pieces of string-like variable-length data are read into a single big buffer, and at the end of the process, only a part of array containing actual data is sent to user-space for further processing. This case is tested in test_varlen.c selftest (in the next patch). Code flow is roughly as follows: void *payload = &sample->payload; u64 len; len = bpf_probe_read_kernel_str(payload, MAX_SZ1, &source_data1); if (len <= MAX_SZ1) { payload += len; sample->len1 = len; } len = bpf_probe_read_kernel_str(payload, MAX_SZ2, &source_data2); if (len <= MAX_SZ2) { payload += len; sample->len2 = len; } /* and so on */ sample->total_len = payload - &sample->payload; /* send over, e.g., perf buffer */ There could be two variations with slightly different code generated: when len is 64-bit integer and when it is 32-bit integer. Both variations were analysed. BPF assembly instructions between two successive invocations of bpf_probe_read_kernel_str() were used to check code regressions. Results are below, followed by short analysis. Left side is using helpers with int return type, the right one is after the switch to long. ALU32 + INT ALU32 + LONG =========== ============ 64-BIT (13 insns): 64-BIT (10 insns): ------------------------------------ ------------------------------------ 17: call 115 17: call 115 18: if w0 > 256 goto +9 <LBB0_4> 18: if r0 > 256 goto +6 <LBB0_4> 19: w1 = w0 19: r1 = 0 ll 20: r1 <<= 32 21: *(u64 *)(r1 + 0) = r0 21: r1 s>>= 32 22: r6 = 0 ll 22: r2 = 0 ll 24: r6 += r0 24: *(u64 *)(r2 + 0) = r1 00000000000000c8 <LBB0_4>: 25: r6 = 0 ll 25: r1 = r6 27: r6 += r1 26: w2 = 256 00000000000000e0 <LBB0_4>: 27: r3 = 0 ll 28: r1 = r6 29: call 115 29: w2 = 256 30: r3 = 0 ll 32: call 115 32-BIT (11 insns): 32-BIT (12 insns): ------------------------------------ ------------------------------------ 17: call 115 17: call 115 18: if w0 > 256 goto +7 <LBB1_4> 18: if w0 > 256 goto +8 <LBB1_4> 19: r1 = 0 ll 19: r1 = 0 ll 21: *(u32 *)(r1 + 0) = r0 21: *(u32 *)(r1 + 0) = r0 22: w1 = w0 22: r0 <<= 32 23: r6 = 0 ll 23: r0 >>= 32 25: r6 += r1 24: r6 = 0 ll 00000000000000d0 <LBB1_4>: 26: r6 += r0 26: r1 = r6 00000000000000d8 <LBB1_4>: 27: w2 = 256 27: r1 = r6 28: r3 = 0 ll 28: w2 = 256 30: call 115 29: r3 = 0 ll 31: call 115 In ALU32 mode, the variant using 64-bit length variable clearly wins and avoids unnecessary zero-extension bit shifts. In practice, this is even more important and good, because BPF code won't need to do extra checks to "prove" that payload/len are within good bounds. 32-bit len is one instruction longer. Clang decided to do 64-to-32 casting with two bit shifts, instead of equivalent `w1 = w0` assignment. The former uses extra register. The latter might potentially lose some range information, but not for 32-bit value. So in this case, verifier infers that r0 is [0, 256] after check at 18:, and shifting 32 bits left/right keeps that range intact. We should probably look into Clang's logic and see why it chooses bitshifts over sub-register assignments for this. NO-ALU32 + INT NO-ALU32 + LONG ============== =============== 64-BIT (14 insns): 64-BIT (10 insns): ------------------------------------ ------------------------------------ 17: call 115 17: call 115 18: r0 <<= 32 18: if r0 > 256 goto +6 <LBB0_4> 19: r1 = r0 19: r1 = 0 ll 20: r1 >>= 32 21: *(u64 *)(r1 + 0) = r0 21: if r1 > 256 goto +7 <LBB0_4> 22: r6 = 0 ll 22: r0 s>>= 32 24: r6 += r0 23: r1 = 0 ll 00000000000000c8 <LBB0_4>: 25: *(u64 *)(r1 + 0) = r0 25: r1 = r6 26: r6 = 0 ll 26: r2 = 256 28: r6 += r0 27: r3 = 0 ll 00000000000000e8 <LBB0_4>: 29: call 115 29: r1 = r6 30: r2 = 256 31: r3 = 0 ll 33: call 115 32-BIT (13 insns): 32-BIT (13 insns): ------------------------------------ ------------------------------------ 17: call 115 17: call 115 18: r1 = r0 18: r1 = r0 19: r1 <<= 32 19: r1 <<= 32 20: r1 >>= 32 20: r1 >>= 32 21: if r1 > 256 goto +6 <LBB1_4> 21: if r1 > 256 goto +6 <LBB1_4> 22: r2 = 0 ll 22: r2 = 0 ll 24: *(u32 *)(r2 + 0) = r0 24: *(u32 *)(r2 + 0) = r0 25: r6 = 0 ll 25: r6 = 0 ll 27: r6 += r1 27: r6 += r1 00000000000000e0 <LBB1_4>: 00000000000000e0 <LBB1_4>: 28: r1 = r6 28: r1 = r6 29: r2 = 256 29: r2 = 256 30: r3 = 0 ll 30: r3 = 0 ll 32: call 115 32: call 115 In NO-ALU32 mode, for the case of 64-bit len variable, Clang generates much superior code, as expected, eliminating unnecessary bit shifts. For 32-bit len, code is identical. So overall, only ALU-32 32-bit len case is more-or-less equivalent and the difference stems from internal Clang decision, rather than compiler lacking enough information about types. Case 2. Let's look at the simpler case of checking return result of BPF helper for errors. The code is very simple: long bla; if (bpf_probe_read_kenerl(&bla, sizeof(bla), 0)) return 1; else return 0; ALU32 + CHECK (9 insns) ALU32 + CHECK (9 insns) ==================================== ==================================== 0: r1 = r10 0: r1 = r10 1: r1 += -8 1: r1 += -8 2: w2 = 8 2: w2 = 8 3: r3 = 0 3: r3 = 0 4: call 113 4: call 113 5: w1 = w0 5: r1 = r0 6: w0 = 1 6: w0 = 1 7: if w1 != 0 goto +1 <LBB2_2> 7: if r1 != 0 goto +1 <LBB2_2> 8: w0 = 0 8: w0 = 0 0000000000000048 <LBB2_2>: 0000000000000048 <LBB2_2>: 9: exit 9: exit Almost identical code, the only difference is the use of full register assignment (r1 = r0) vs half-registers (w1 = w0) in instruction #5. On 32-bit architectures, new BPF assembly might be slightly less optimal, in theory. But one can argue that's not a big issue, given that use of full registers is still prevalent (e.g., for parameter passing). NO-ALU32 + CHECK (11 insns) NO-ALU32 + CHECK (9 insns) ==================================== ==================================== 0: r1 = r10 0: r1 = r10 1: r1 += -8 1: r1 += -8 2: r2 = 8 2: r2 = 8 3: r3 = 0 3: r3 = 0 4: call 113 4: call 113 5: r1 = r0 5: r1 = r0 6: r1 <<= 32 6: r0 = 1 7: r1 >>= 32 7: if r1 != 0 goto +1 <LBB2_2> 8: r0 = 1 8: r0 = 0 9: if r1 != 0 goto +1 <LBB2_2> 0000000000000048 <LBB2_2>: 10: r0 = 0 9: exit 0000000000000058 <LBB2_2>: 11: exit NO-ALU32 is a clear improvement, getting rid of unnecessary zero-extension bit shifts. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200623032224.4020118-1-andriin@fb.com
* | tools/bpftool: Add documentation and sample output for process infoAndrii Nakryiko2020-06-224-2/+35
| | | | | | | | | | | | | | | | | | | | Add statements about bpftool being able to discover process info, holding reference to BPF map, prog, link, or BTF. Show example output as well. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-10-andriin@fb.com
* | tools/bpftool: Show info for processes holding BPF map/prog/link/btf FDsAndrii Nakryiko2020-06-2210-0/+378
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add bpf_iter-based way to find all the processes that hold open FDs against BPF object (map, prog, link, btf). bpftool always attempts to discover this, but will silently give up if kernel doesn't yet support bpf_iter BPF programs. Process name and PID are emitted for each process (task group). Sample output for each of 4 BPF objects: $ sudo ./bpftool prog show 2694: cgroup_device tag 8c42dee26e8cd4c2 gpl loaded_at 2020-06-16T15:34:32-0700 uid 0 xlated 648B jited 409B memlock 4096B pids systemd(1) 2907: cgroup_skb name egress tag 9ad187367cf2b9e8 gpl loaded_at 2020-06-16T18:06:54-0700 uid 0 xlated 48B jited 59B memlock 4096B map_ids 2436 btf_id 1202 pids test_progs(2238417), test_progs(2238445) $ sudo ./bpftool map show 2436: array name test_cgr.bss flags 0x400 key 4B value 8B max_entries 1 memlock 8192B btf_id 1202 pids test_progs(2238417), test_progs(2238445) 2445: array name pid_iter.rodata flags 0x480 key 4B value 4B max_entries 1 memlock 8192B btf_id 1214 frozen pids bpftool(2239612) $ sudo ./bpftool link show 61: cgroup prog 2908 cgroup_id 375301 attach_type egress pids test_progs(2238417), test_progs(2238445) 62: cgroup prog 2908 cgroup_id 375344 attach_type egress pids test_progs(2238417), test_progs(2238445) $ sudo ./bpftool btf show 1202: size 1527B prog_ids 2908,2907 map_ids 2436 pids test_progs(2238417), test_progs(2238445) 1242: size 34684B pids bpftool(2258892) Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-9-andriin@fb.com
* | libbpf: Wrap source argument of BPF_CORE_READ macro in parenthesesAndrii Nakryiko2020-06-221-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | Wrap source argument of BPF_CORE_READ family of macros into parentheses to allow uses like this: BPF_CORE_READ((struct cast_struct *)src, a, b, c); Fixes: 7db3822ab991 ("libbpf: Add BPF_CORE_READ/BPF_CORE_READ_INTO helpers") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200619231703.738941-8-andriin@fb.com
* | tools/bpftool: Generalize BPF skeleton support and generate vmlinux.hAndrii Nakryiko2020-06-227-66/+45
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Adapt Makefile to support BPF skeleton generation beyond single profiler.bpf.c case. Also add vmlinux.h generation and switch profiler.bpf.c to use it. clang-bpf-global-var feature is extended and renamed to clang-bpf-co-re to check for support of preserve_access_index attribute, which, together with BTF for global variables, is the minimum requirement for modern BPF programs. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-7-andriin@fb.com
* | tools/bpftool: Minimize bootstrap bpftoolAndrii Nakryiko2020-06-224-32/+38
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Build minimal "bootstrap mode" bpftool to enable skeleton (and, later, vmlinux.h generation), instead of building almost complete, but slightly different (w/o skeletons, etc) bpftool to bootstrap complete bpftool build. Current approach doesn't scale well (engineering-wise) when adding more BPF programs to bpftool and other complicated functionality, as it requires constant adjusting of the code to work in both bootstrapped mode and normal mode. So it's better to build only minimal bpftool version that supports only BPF skeleton code generation and BTF-to-C conversion. Thankfully, this is quite easy to accomplish due to internal modularity of bpftool commands. This will also allow to keep adding new functionality to bpftool in general, without the need to care about bootstrap mode for those new parts of bpftool. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-6-andriin@fb.com
* | tools/bpftool: Move map/prog parsing logic into commonAndrii Nakryiko2020-06-224-308/+310
| | | | | | | | | | | | | | | | | | | | | | | | | | Move functions that parse map and prog by id/tag/name/etc outside of map.c/prog.c, respectively. These functions are used outside of those files and are generic enough to be in common. This also makes heavy-weight map.c and prog.c more decoupled from the rest of bpftool files and facilitates more lightweight bootstrap bpftool variant. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-5-andriin@fb.com
* | selftests/bpf: Add __ksym extern selftestAndrii Nakryiko2020-06-222-0/+103
| | | | | | | | | | | | | | | | | | | | Validate libbpf is able to handle weak and strong kernel symbol externs in BPF code correctly. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Hao Luo <haoluo@google.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-4-andriin@fb.com
* | libbpf: Add support for extracting kernel symbol addressesAndrii Nakryiko2020-06-223-6/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for another (in addition to existing Kconfig) special kind of externs in BPF code, kernel symbol externs. Such externs allow BPF code to "know" kernel symbol address and either use it for comparisons with kernel data structures (e.g., struct file's f_op pointer, to distinguish different kinds of file), or, with the help of bpf_probe_user_kernel(), to follow pointers and read data from global variables. Kernel symbol addresses are found through /proc/kallsyms, which should be present in the system. Currently, such kernel symbol variables are typeless: they have to be defined as `extern const void <symbol>` and the only operation you can do (in C code) with them is to take its address. Such extern should reside in a special section '.ksyms'. bpf_helpers.h header provides __ksym macro for this. Strong vs weak semantics stays the same as with Kconfig externs. If symbol is not found in /proc/kallsyms, this will be a failure for strong (non-weak) extern, but will be defaulted to 0 for weak externs. If the same symbol is defined multiple times in /proc/kallsyms, then it will be error if any of the associated addresses differs. In that case, address is ambiguous, so libbpf falls on the side of caution, rather than confusing user with randomly chosen address. In the future, once kernel is extended with variables BTF information, such ksym externs will be supported in a typed version, which will allow BPF program to read variable's contents directly, similarly to how it's done for fentry/fexit input arguments. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Hao Luo <haoluo@google.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-3-andriin@fb.com
* | libbpf: Generalize libbpf externs supportAndrii Nakryiko2020-06-221-140/+206
| | | | | | | | | | | | | | | | | | | | | | | | Switch existing Kconfig externs to be just one of few possible kinds of more generic externs. This refactoring is in preparation for ksymbol extern support, added in the follow up patch. There are no functional changes intended. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Hao Luo <haoluo@google.com> Link: https://lore.kernel.org/bpf/20200619231703.738941-2-andriin@fb.com
* | libbpf: Add a bunch of attribute getters/setters for map definitionsAndrii Nakryiko2020-06-233-10/+134
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a bunch of getter for various aspects of BPF map. Some of these attribute (e.g., key_size, value_size, type, etc) are available right now in struct bpf_map_def, but this patch adds getter allowing to fetch them individually. bpf_map_def approach isn't very scalable, when ABI stability requirements are taken into account. It's much easier to extend libbpf and add support for new features, when each aspect of BPF map has separate getter/setter. Getters follow the common naming convention of not explicitly having "get" in its name: bpf_map__type() returns map type, bpf_map__key_size() returns key_size. Setters, though, explicitly have set in their name: bpf_map__set_type(), bpf_map__set_key_size(). This patch ensures we now have a getter and a setter for the following map attributes: - type; - max_entries; - map_flags; - numa_node; - key_size; - value_size; - ifindex. bpf_map__resize() enforces unnecessary restriction of max_entries > 0. It is unnecessary, because libbpf actually supports zero max_entries for some cases (e.g., for PERF_EVENT_ARRAY map) and treats it specially during map creation time. To allow setting max_entries=0, new bpf_map__set_max_entries() setter is added. bpf_map__resize()'s behavior is preserved for backwards compatibility reasons. Map ifindex getter is added as well. There is a setter already, but no corresponding getter. Fix this assymetry as well. bpf_map__set_ifindex() itself is converted from void function into error-returning one, similar to other setters. The only error returned right now is -EBUSY, if BPF map is already loaded and has corresponding FD. One lacking attribute with no ability to get/set or even specify it declaratively is numa_node. This patch fixes this gap and both adds programmatic getter/setter, as well as adds support for numa_node field in BTF-defined map. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200621062112.3006313-1-andriin@fb.com
* | selftests/bpf: Test access to bpf map pointerAndrey Ignatov2020-06-223-0/+780
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add selftests to test access to map pointers from bpf program for all map types except struct_ops (that one would need additional work). verifier test focuses mostly on scenarios that must be rejected. prog_tests test focuses on accessing multiple fields both scalar and a nested struct from bpf program and verifies that those fields have expected values. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/139a6a17f8016491e39347849b951525335c6eb4.1592600985.git.rdna@fb.com
* | bpf: Support access to bpf map fieldsAndrey Ignatov2020-06-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are multiple use-cases when it's convenient to have access to bpf map fields, both `struct bpf_map` and map type specific struct-s such as `struct bpf_array`, `struct bpf_htab`, etc. For example while working with sock arrays it can be necessary to calculate the key based on map->max_entries (some_hash % max_entries). Currently this is solved by communicating max_entries via "out-of-band" channel, e.g. via additional map with known key to get info about target map. That works, but is not very convenient and error-prone while working with many maps. In other cases necessary data is dynamic (i.e. unknown at loading time) and it's impossible to get it at all. For example while working with a hash table it can be convenient to know how much capacity is already used (bpf_htab.count.counter for BPF_F_NO_PREALLOC case). At the same time kernel knows this info and can provide it to bpf program. Fill this gap by adding support to access bpf map fields from bpf program for both `struct bpf_map` and map type specific fields. Support is implemented via btf_struct_access() so that a user can define their own `struct bpf_map` or map type specific struct in their program with only necessary fields and preserve_access_index attribute, cast a map to this struct and use a field. For example: struct bpf_map { __u32 max_entries; } __attribute__((preserve_access_index)); struct bpf_array { struct bpf_map map; __u32 elem_size; } __attribute__((preserve_access_index)); struct { __uint(type, BPF_MAP_TYPE_ARRAY); __uint(max_entries, 4); __type(key, __u32); __type(value, __u32); } m_array SEC(".maps"); SEC("cgroup_skb/egress") int cg_skb(void *ctx) { struct bpf_array *array = (struct bpf_array *)&m_array; struct bpf_map *map = (struct bpf_map *)&m_array; /* .. use map->max_entries or array->map.max_entries .. */ } Similarly to other btf_struct_access() use-cases (e.g. struct tcp_sock in net/ipv4/bpf_tcp_ca.c) the patch allows access to any fields of corresponding struct. Only reading from map fields is supported. For btf_struct_access() to work there should be a way to know btf id of a struct that corresponds to a map type. To get btf id there should be a way to get a stringified name of map-specific struct, such as "bpf_array", "bpf_htab", etc for a map type. Two new fields are added to `struct bpf_map_ops` to handle it: * .map_btf_name keeps a btf name of a struct returned by map_alloc(); * .map_btf_id is used to cache btf id of that struct. To make btf ids calculation cheaper they're calculated once while preparing btf_vmlinux and cached same way as it's done for btf_id field of `struct bpf_func_proto` While calculating btf ids, struct names are NOT checked for collision. Collisions will be checked as a part of the work to prepare btf ids used in verifier in compile time that should land soon. The only known collision for `struct bpf_htab` (kernel/bpf/hashtab.c vs net/core/sock_map.c) was fixed earlier. Both new fields .map_btf_name and .map_btf_id must be set for a map type for the feature to work. If neither is set for a map type, verifier will return ENOTSUPP on a try to access map_ptr of corresponding type. If just one of them set, it's verifier misconfiguration. Only `struct bpf_array` for BPF_MAP_TYPE_ARRAY and `struct bpf_htab` for BPF_MAP_TYPE_HASH are supported by this patch. Other map types will be supported separately. The feature is available only for CONFIG_DEBUG_INFO_BTF=y and gated by perfmon_capable() so that unpriv programs won't have access to bpf map fields. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/6479686a0cd1e9067993df57b4c3eef0e276fec9.1592600985.git.rdna@fb.com
* | tools/bpftool: Relicense bpftool's BPF profiler prog as dual-license GPL/BSDAndrii Nakryiko2020-06-201-2/+2
| | | | | | | | | | | | | | | | | | Relicense it to be compatible with the rest of bpftool files. Suggested-by: Quentin Monnet <quentin@isovalent.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200619222024.519774-1-andriin@fb.com
* | tools/bpf: Add verifier tests for 32bit pointer/scalar arithmeticYonghong Song2020-06-191-0/+38
| | | | | | | | | | | | | | | | | | Added two test_verifier subtests for 32bit pointer/scalar arithmetic with BPF_SUB operator. They are passing verifier now. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200618234632.3321367-1-yhs@fb.com
* | libbpf: Bump version to 0.1.0Andrii Nakryiko2020-06-171-0/+3
| | | | | | | | | | | | | | | | Bump libbpf version to 0.1.0, as new development cycle starts. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200617183132.1970836-1-andriin@fb.com
* | tools/testing/nvdimm: Replace zero-length array with flexible-arrayGustavo A. R. Silva2020-06-151-3/+3
|/ | | | | | | | | | | | There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://github.com/KSPP/linux/issues/21 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds2020-06-1318-52/+331
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull networking fixes from David Miller: 1) Fix cfg80211 deadlock, from Johannes Berg. 2) RXRPC fails to send norigications, from David Howells. 3) MPTCP RM_ADDR parsing has an off by one pointer error, fix from Geliang Tang. 4) Fix crash when using MSG_PEEK with sockmap, from Anny Hu. 5) The ucc_geth driver needs __netdev_watchdog_up exported, from Valentin Longchamp. 6) Fix hashtable memory leak in dccp, from Wang Hai. 7) Fix how nexthops are marked as FDB nexthops, from David Ahern. 8) Fix mptcp races between shutdown and recvmsg, from Paolo Abeni. 9) Fix crashes in tipc_disc_rcv(), from Tuong Lien. 10) Fix link speed reporting in iavf driver, from Brett Creeley. 11) When a channel is used for XSK and then reused again later for XSK, we forget to clear out the relevant data structures in mlx5 which causes all kinds of problems. Fix from Maxim Mikityanskiy. 12) Fix memory leak in genetlink, from Cong Wang. 13) Disallow sockmap attachments to UDP sockets, it simply won't work. From Lorenz Bauer. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (83 commits) net: ethernet: ti: ale: fix allmulti for nu type ale net: ethernet: ti: am65-cpsw-nuss: fix ale parameters init net: atm: Remove the error message according to the atomic context bpf: Undo internal BPF_PROBE_MEM in BPF insns dump libbpf: Support pre-initializing .bss global variables tools/bpftool: Fix skeleton codegen bpf: Fix memlock accounting for sock_hash bpf: sockmap: Don't attach programs to UDP sockets bpf: tcp: Recv() should return 0 when the peer socket is closed ibmvnic: Flush existing work items before device removal genetlink: clean up family attributes allocations net: ipa: header pad field only valid for AP->modem endpoint net: ipa: program upper nibbles of sequencer type net: ipa: fix modem LAN RX endpoint id net: ipa: program metadata mask differently ionic: add pcie_print_link_status rxrpc: Fix race between incoming ACK parser and retransmitter net/mlx5: E-Switch, Fix some error pointer dereferences net/mlx5: Don't fail driver on failure to create debugfs net/mlx5e: CT: Fix ipv6 nat header rewrite actions ...
| * Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpfDavid S. Miller2020-06-1315-50/+264
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== pull-request: bpf 2020-06-12 The following pull-request contains BPF updates for your *net* tree. We've added 26 non-merge commits during the last 10 day(s) which contain a total of 27 files changed, 348 insertions(+), 93 deletions(-). The main changes are: 1) sock_hash accounting fix, from Andrey. 2) libbpf fix and probe_mem sanitizing, from Andrii. 3) sock_hash fixes, from Jakub. 4) devmap_val fix, from Jesper. 5) load_bytes_relative fix, from YiFei. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| | * libbpf: Support pre-initializing .bss global variablesAndrii Nakryiko2020-06-123-13/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove invalid assumption in libbpf that .bss map doesn't have to be updated in kernel. With addition of skeleton and memory-mapped initialization image, .bss doesn't have to be all zeroes when BPF map is created, because user-code might have initialized those variables from user-space. Fixes: eba9c5f498a1 ("libbpf: Refactor global data map initialization") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200612194504.557844-1-andriin@fb.com
| | * tools/bpftool: Fix skeleton codegenAndrii Nakryiko2020-06-121-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove unnecessary check at the end of codegen() routine which makes codegen() to always fail and exit bpftool with error code. Positive value of variable n is not an indicator of a failure. Fixes: 2c4779eff837 ("tools, bpftool: Exit on error in function codegen") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Tobias Klauser <tklauser@distanz.ch> Link: https://lore.kernel.org/bpf/20200612201603.680852-1-andriin@fb.com
| | * tools, bpftool: Exit on error in function codegenTobias Klauser2020-06-111-5/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, the codegen function might fail and return an error. But its callers continue without checking its return value. Since codegen can fail only in the unlikely case of the system running out of memory or the static template being malformed, just exit(-1) directly from codegen and make it void-returning. Suggested-by: Andrii Nakryiko <andrii.nakryiko@gmail.com> Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200611103341.21532-1-tklauser@distanz.ch
| | * tools, bpftool: Fix memory leak in codegen error casesTobias Klauser2020-06-111-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Free the memory allocated for the template on error paths in function codegen. Signed-off-by: Tobias Klauser <tklauser@distanz.ch> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200610130804.21423-1-tklauser@distanz.ch
| | * selftests/bpf: Add cgroup_skb/egress test for load_bytes_relativeYiFei Zhu2020-06-112-0/+119
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When cgroup_skb/egress triggers the MAC header is not set. Added a test that asserts reading MAC header is a -EFAULT but NET header succeeds. The test result from within the eBPF program is stored in an 1-element array map that the userspace then reads and asserts on. Another assertion is added that reading from a large offset, past the end of packet, returns -EFAULT. Signed-off-by: YiFei Zhu <zhuyifei@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/9028ccbea4385a620e69c0a104f469ffd655c01e.1591812755.git.zhuyifei@google.com
| | * tools, bpf: Do not force gcc as CCBrett Mastbergen2020-06-101-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows transparent cross-compilation with CROSS_COMPILE by relying on 7ed1c1901fe5 ("tools: fix cross-compile var clobbering"). Same change was applied to tools/bpf/bpftool/Makefile in 9e88b9312acb ("tools: bpftool: do not force gcc as CC"). Signed-off-by: Brett Mastbergen <brett.mastbergen@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200609213506.3299-1-brett.mastbergen@gmail.com
| | * libbpf: Handle GCC noreturn-turned-volatile quirkAndrii Nakryiko2020-06-101-9/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Handle a GCC quirk of emitting extra volatile modifier in DWARF (and subsequently preserved in BTF by pahole) for function pointers marked as __attribute__((noreturn)). This was the way to mark such functions before GCC 2.5 added noreturn attribute. Drop such func_proto modifiers, similarly to how it's done for array (also to handle GCC quirk/bug). Such volatile attribute is emitted by GCC only, so existing selftests can't express such test. Simple repro is like this (compiled with GCC + BTF generated by pahole): struct my_struct { void __attribute__((noreturn)) (*fn)(int); }; struct my_struct a; Without this fix, output will be: struct my_struct { voidvolatile (*fn)(int); }; With the fix: struct my_struct { void (*fn)(int); }; Fixes: 351131b51c7a ("libbpf: add btf_dump API for BTF-to-C conversion") Reported-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Link: https://lore.kernel.org/bpf/20200610052335.2862559-1-andriin@fb.com
| | * libbpf: Define __WORDSIZE if not availableArnaldo Carvalho de Melo2020-06-101-4/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some systems, such as Android, don't have a define for __WORDSIZE, do it in terms of __SIZEOF_LONG__, as done in perf since 2012: http://git.kernel.org/torvalds/c/3f34f6c0233ae055b5 For reference: https://gcc.gnu.org/onlinedocs/cpp/Common-Predefined-Macros.html I build tested it here and Andrii did some Travis CI build tests too. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200608161150.GA3073@kernel.org
| | * bpf: Selftests and tools use struct bpf_devmap_val from uapiJesper Dangaard Brouer2020-06-094-11/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | Sync tools uapi bpf.h header file and update selftests that use struct bpf_devmap_val. Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/159170951195.2102545.1833108712124273987.stgit@firesoul
| | * bpf: cgroup: Allow multi-attach program to replace itselfLorenz Bauer2020-06-091-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When using BPF_PROG_ATTACH to attach a program to a cgroup in BPF_F_ALLOW_MULTI mode, it is not possible to replace a program with itself. This is because the check for duplicate programs doesn't take the replacement program into account. Replacing a program with itself might seem weird, but it has some uses: first, it allows resetting the associated cgroup storage. Second, it makes the API consistent with the non-ALLOW_MULTI usage, where it is possible to replace a program with itself. Third, it aligns BPF_PROG_ATTACH with bpf_link, where replacing itself is also supported. Sice this code has been refactored a few times this change will only apply to v5.7 and later. Adjustments could be made to commit 1020c1f24a94 ("bpf: Simplify __cgroup_bpf_attach") and commit d7bf2c10af05 ("bpf: allocate cgroup storage entries on attaching bpf programs") as well as commit 324bda9e6c5a ("bpf: multi program support for cgroup+bpf") Fixes: af6eea57437a ("bpf: Implement bpf_link-based cgroup BPF program attachment") Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200608162202.94002-1-lmb@cloudflare.com
| | * selftests/bpf: Fix ringbuf selftest sample counting undeterminismAndrii Nakryiko2020-06-081-7/+35
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix test race, in which background poll can get either 5 or 6 samples, depending on timing of notification. Prevent this by open-coding sample triggering and forcing notification for the very last sample only. Also switch to using atomic increments and exchanges for more obviously reliable counting and checking. Additionally, check expected processed sample counters for single-threaded use cases as well. Fixes: 9a5f25ad30e5 ("selftests/bpf: Fix sample_cnt shared between two threads") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20200608003615.3549991-1-andriin@fb.com
| * | selftests/net: in rxtimestamp getopt_long needs terminating null entrytannerlove2020-06-091-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | getopt_long requires the last element to be filled with zeros. Otherwise, passing an unrecognized option can cause a segfault. Fixes: 16e781224198 ("selftests/net: Add a test to validate behavior of rx timestamps") Signed-off-by: Tanner Love <tannerlove@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | selftests/net: in timestamping, strncpy needs to preserve null bytetannerlove2020-06-081-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If user passed an interface option longer than 15 characters, then device.ifr_name and hwtstamp.ifr_name became non-null-terminated strings. The compiler warned about this: timestamping.c:353:2: warning: ‘strncpy’ specified bound 16 equals \ destination size [-Wstringop-truncation] 353 | strncpy(device.ifr_name, interface, sizeof(device.ifr_name)); Fixes: cb9eff097831 ("net: new user space API for time stamping of incoming and outgoing packets") Signed-off-by: Tanner Love <tannerlove@google.com> Acked-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>