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* libbpf: Allow passing user log setting through bpf_object_open_optsAndrii Nakryiko2021-12-113-3/+65
| | | | | | | | | | | | | | | | | | | | Allow users to provide their own custom log_buf, log_size, and log_level at bpf_object level through bpf_object_open_opts. This log_buf will be used during BTF loading. Subsequent patch will use same log_buf during BPF program loading, unless overriden at per-bpf_program level. When such custom log_buf is provided, libbpf won't be attempting retrying loading of BTF to try to provide its own log buffer to capture kernel's error log output. User is responsible to provide big enough buffer, otherwise they run a risk of getting -ENOSPC error from the bpf() syscall. See also comments in bpf_object_open_opts regarding log_level and log_buf interactions. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-5-andrii@kernel.org
* libbpf: Allow passing preallocated log_buf when loading BTF into kernelAndrii Nakryiko2021-12-112-23/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add libbpf-internal btf_load_into_kernel() that allows to pass preallocated log_buf and custom log_level to be passed into kernel during BPF_BTF_LOAD call. When custom log_buf is provided, btf_load_into_kernel() won't attempt an retry with automatically allocated internal temporary buffer to capture BTF validation log. It's important to note the relation between log_buf and log_level, which slightly deviates from stricter kernel logic. From kernel's POV, if log_buf is specified, log_level has to be > 0, and vice versa. While kernel has good reasons to request such "sanity, this, in practice, is a bit unconvenient and restrictive for libbpf's high-level bpf_object APIs. So libbpf will allow to set non-NULL log_buf and log_level == 0. This is fine and means to attempt to load BTF without logging requested, but if it failes, retry the load with custom log_buf and log_level 1. Similar logic will be implemented for program loading. In practice this means that users can provide custom log buffer just in case error happens, but not really request slower verbose logging all the time. This is also consistent with libbpf behavior when custom log_buf is not set: libbpf first tries to load everything with log_level=0, and only if error happens allocates internal log buffer and retries with log_level=1. Also, while at it, make BTF validation log more obvious and follow the log pattern libbpf is using for dumping BPF verifier log during BPF_PROG_LOAD. BTF loading resulting in an error will look like this: libbpf: BTF loading error: -22 libbpf: -- BEGIN BTF LOAD LOG --- magic: 0xeb9f version: 1 flags: 0x0 hdr_len: 24 type_off: 0 type_len: 1040 str_off: 1040 str_len: 2063598257 btf_total_size: 1753 Total section length too long -- END BTF LOAD LOG -- libbpf: Error loading .BTF into kernel: -22. BTF is optional, ignoring. This makes it much easier to find relevant parts in libbpf log output. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-4-andrii@kernel.org
* libbpf: Add OPTS-based bpf_btf_load() APIAndrii Nakryiko2021-12-114-12/+69
| | | | | | | | | | | | | | | | | | | | | | | Similar to previous bpf_prog_load() and bpf_map_create() APIs, add bpf_btf_load() API which is taking optional OPTS struct. Schedule bpf_load_btf() for deprecation in v0.8 ([0]). This makes naming consistent with BPF_BTF_LOAD command, sets up an API for extensibility in the future, moves options parameters (log-related fields) into optional options, and also allows to pass log_level directly. It also removes log buffer auto-allocation logic from low-level API (consistent with bpf_prog_load() behavior), but preserves a special treatment of log_level == 0 with non-NULL log_buf, which matches low-level bpf_prog_load() and high-level libbpf APIs for BTF and program loading behaviors. [0] Closes: https://github.com/libbpf/libbpf/issues/419 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-3-andrii@kernel.org
* libbpf: Fix bpf_prog_load() log_buf logic for log_level 0Andrii Nakryiko2021-12-111-13/+16
| | | | | | | | | | | | | | | | | | | | | To unify libbpf APIs behavior w.r.t. log_buf and log_level, fix bpf_prog_load() to follow the same logic as bpf_btf_load() and high-level bpf_object__load() API will follow in the subsequent patches: - if log_level is 0 and non-NULL log_buf is provided by a user, attempt load operation initially with no log_buf and log_level set; - if successful, we are done, return new FD; - on error, retry the load operation with log_level bumped to 1 and log_buf set; this way verbose logging will be requested only when we are sure that there is a failure, but will be fast in the common/expected success case. Of course, user can still specify log_level > 0 from the very beginning to force log collection. Suggested-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211209193840.1248570-2-andrii@kernel.org
* samples/bpf: Remove unneeded variableMinghao Chi2021-12-091-3/+1
| | | | | | | | | Return value directly instead of taking this in another redundant variable. Reported-by: Zeal Robot <zealci@zte.com.cm> Signed-off-by: Minghao Chi <chi.minghao@zte.com.cn> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211209080051.421844-1-chi.minghao@zte.com.cn
* bpf: Remove redundant assignment to pointer tColin Ian King2021-12-091-1/+1
| | | | | | | | | | The pointer t is being initialized with a value that is never read. The pointer is re-assigned a value a littler later on, hence the initialization is redundant and can be removed. Signed-off-by: Colin Ian King <colin.i.king@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211207224718.59593-1-colin.i.king@gmail.com
* selftests/bpf: Fix a compilation warningYonghong Song2021-12-091-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | The following warning is triggered when I used clang compiler to build the selftest. /.../prog_tests/btf_dedup_split.c:368:6: warning: variable 'btf2' is used uninitialized whenever 'if' condition is true [-Wsometimes-uninitialized] if (!ASSERT_OK(err, "btf_dedup")) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~ /.../prog_tests/btf_dedup_split.c:424:12: note: uninitialized use occurs here btf__free(btf2); ^~~~ /.../prog_tests/btf_dedup_split.c:368:2: note: remove the 'if' if its condition is always false if (!ASSERT_OK(err, "btf_dedup")) ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /.../prog_tests/btf_dedup_split.c:343:25: note: initialize the variable 'btf2' to silence this warning struct btf *btf1, *btf2; ^ = NULL Initialize local variable btf2 = NULL and the warning is gone. Fixes: 9a49afe6f5a5 ("selftests/bpf: Add btf_dedup case with duplicated structs within CU") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211209050403.1770836-1-yhs@fb.com
* perf/bpf_counter: Use bpf_map_create instead of bpf_create_mapSong Liu2021-12-081-2/+16
| | | | | | | | | | | bpf_create_map is deprecated. Replace it with bpf_map_create. Also add a __weak bpf_map_create() so that when older version of libbpf is linked as a shared library, it falls back to bpf_create_map(). Fixes: 992c4225419a ("libbpf: Unify low-level map creation APIs w/ new bpf_map_create()") Signed-off-by: Song Liu <song@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211207232340.2561471-1-song@kernel.org
* Merge branch 'samples: bpf: fix build issues with Clang/LLVM'Andrii Nakryiko2021-12-072-1/+8
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexander Lobakin says: ==================== Samples, at least XDP ones, can be built only with the compiler used to build the kernel itself. However, XDP sample infra introduced in Aug'21 was probably tested with GCC/Binutils only as it's not really compilable for now with Clang/LLVM. These two are trivial fixes addressing this. ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
| * samples: bpf: Fix 'unknown warning group' build warning on ClangAlexander Lobakin2021-12-071-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clang doesn't have 'stringop-truncation' group like GCC does, and complains about it when building samples which use xdp_sample_user infra: samples/bpf/xdp_sample_user.h:48:32: warning: unknown warning group '-Wstringop-truncation', ignored [-Wunknown-warning-option] #pragma GCC diagnostic ignored "-Wstringop-truncation" ^ [ repeat ] Those are harmless, but avoidable when guarding it with ifdef. I could guard push/pop as well, but this would require one more ifdef cruft around a single line which I don't think is reasonable. Fixes: 156f886cf697 ("samples: bpf: Add basic infrastructure for XDP samples") Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20211203195004.5803-3-alexandr.lobakin@intel.com
| * samples: bpf: Fix xdp_sample_user.o linking with ClangAlexander Lobakin2021-12-071-1/+6
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clang (13) doesn't get the jokes about specifying libraries to link in cclags of individual .o objects: clang-13: warning: -lm: 'linker' input unused [-Wunused-command-line-argument] [ ... ] LD samples/bpf/xdp_redirect_cpu LD samples/bpf/xdp_redirect_map_multi LD samples/bpf/xdp_redirect_map LD samples/bpf/xdp_redirect LD samples/bpf/xdp_monitor /usr/bin/ld: samples/bpf/xdp_sample_user.o: in function `sample_summary_print': xdp_sample_user.c:(.text+0x84c): undefined reference to `floor' /usr/bin/ld: xdp_sample_user.c:(.text+0x870): undefined reference to `ceil' /usr/bin/ld: xdp_sample_user.c:(.text+0x8cf): undefined reference to `floor' /usr/bin/ld: xdp_sample_user.c:(.text+0x8f3): undefined reference to `ceil' [ more ] Specify '-lm' as ldflags for all xdp_sample_user.o users in the main Makefile and remove it from ccflags of ^ in Makefile.target -- just like it's done for all other samples. This works with all compilers. Fixes: 6e1051a54e31 ("samples: bpf: Convert xdp_monitor to XDP samples helper") Fixes: b926c55d856c ("samples: bpf: Convert xdp_redirect to XDP samples helper") Fixes: e531a220cc59 ("samples: bpf: Convert xdp_redirect_cpu to XDP samples helper") Fixes: bbe65865aa05 ("samples: bpf: Convert xdp_redirect_map to XDP samples helper") Fixes: 594a116b2aa1 ("samples: bpf: Convert xdp_redirect_map_multi to XDP samples helper") Signed-off-by: Alexander Lobakin <alexandr.lobakin@intel.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Kumar Kartikeya Dwivedi <memxor@gmail.com> Link: https://lore.kernel.org/bpf/20211203195004.5803-2-alexandr.lobakin@intel.com
* bpf: Silence purge_cand_cache build warning.Alexei Starovoitov2021-12-071-0/+2
| | | | | | | | | | | | When CONFIG_DEBUG_INFO_BTF_MODULES is not set the following warning can be seen: kernel/bpf/btf.c:6588:13: warning: 'purge_cand_cache' defined but not used [-Wunused-function] Fix it. Fixes: 1e89106da253 ("bpf: Add bpf_core_add_cands() and wire it into bpf_core_apply_relo_insn().") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211207014839.6976-1-alexei.starovoitov@gmail.com
* libbpf: Add doc comments in libbpf.hGrant Seltzer2021-12-061-0/+53
| | | | | | | | | | | | | | | | | This adds comments above functions in libbpf.h which document their uses. These comments are of a format that doxygen and sphinx can pick up and render. These are rendered by libbpf.readthedocs.org These doc comments are for: - bpf_object__open_file() - bpf_object__open_mem() - bpf_program__attach_uprobe() - bpf_program__attach_uprobe_opts() Signed-off-by: Grant Seltzer <grantseltzer@gmail.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211206203709.332530-1-grantseltzer@gmail.com
* libbpf: Fix trivial typohuangxuesen2021-12-061-2/+2
| | | | | | | | | Fix typo in comment from 'bpf_skeleton_map' to 'bpf_map_skeleton' and from 'bpf_skeleton_prog' to 'bpf_prog_skeleton'. Signed-off-by: huangxuesen <huangxuesen@kuaishou.com> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/1638755236-3851199-1-git-send-email-hxseverything@gmail.com
* bpf: Remove config check to enable bpf support for branch recordsKajol Jain2021-12-061-5/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Branch data available to BPF programs can be very useful to get stack traces out of userspace application. Commit fff7b64355ea ("bpf: Add bpf_read_branch_records() helper") added BPF support to capture branch records in x86. Enable this feature also for other architectures as well by removing checks specific to x86. If an architecture doesn't support branch records, bpf_read_branch_records() still has appropriate checks and it will return an -EINVAL in that scenario. Based on UAPI helper doc in include/uapi/linux/bpf.h, unsupported architectures should return -ENOENT in such case. Hence, update the appropriate check to return -ENOENT instead. Selftest 'perf_branches' result on power9 machine which has the branch stacks support: - Before this patch: [command]# ./test_progs -t perf_branches #88/1 perf_branches/perf_branches_hw:FAIL #88/2 perf_branches/perf_branches_no_hw:OK #88 perf_branches:FAIL Summary: 0/1 PASSED, 0 SKIPPED, 1 FAILED - After this patch: [command]# ./test_progs -t perf_branches #88/1 perf_branches/perf_branches_hw:OK #88/2 perf_branches/perf_branches_no_hw:OK #88 perf_branches:OK Summary: 1/2 PASSED, 0 SKIPPED, 0 FAILED Selftest 'perf_branches' result on power9 machine which doesn't have branch stack report: - After this patch: [command]# ./test_progs -t perf_branches #88/1 perf_branches/perf_branches_hw:SKIP #88/2 perf_branches/perf_branches_no_hw:OK #88 perf_branches:OK Summary: 1/1 PASSED, 1 SKIPPED, 0 FAILED Fixes: fff7b64355eac ("bpf: Add bpf_read_branch_records() helper") Suggested-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Kajol Jain <kjain@linux.ibm.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211206073315.77432-1-kjain@linux.ibm.com
* bpftool: Add debug mode for gen_loader.Alexei Starovoitov2021-12-051-9/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make -d flag functional for gen_loader style program loading. For example: $ bpftool prog load -L -d test_d_path.o ... // will print: libbpf: loading ./test_d_path.o libbpf: elf: section(3) fentry/security_inode_getattr, size 280, link 0, flags 6, type=1 ... libbpf: prog 'prog_close': found data map 0 (test_d_p.bss, sec 7, off 0) for insn 30 libbpf: gen: load_btf: size 5376 libbpf: gen: map_create: test_d_p.bss idx 0 type 2 value_type_id 118 libbpf: map 'test_d_p.bss': created successfully, fd=0 libbpf: gen: map_update_elem: idx 0 libbpf: sec 'fentry/filp_close': found 1 CO-RE relocations libbpf: record_relo_core: prog 1 insn[15] struct file 0:1 final insn_idx 15 libbpf: gen: prog_load: type 26 insns_cnt 35 progi_idx 0 libbpf: gen: find_attach_tgt security_inode_getattr 12 libbpf: gen: prog_load: type 26 insns_cnt 37 progi_idx 1 libbpf: gen: find_attach_tgt filp_close 12 libbpf: gen: finish 0 ... // at this point libbpf finished generating loader program 0: (bf) r6 = r1 1: (bf) r1 = r10 2: (07) r1 += -136 3: (b7) r2 = 136 4: (b7) r3 = 0 5: (85) call bpf_probe_read_kernel#113 6: (05) goto pc+104 ... // this is the assembly dump of the loader program 390: (63) *(u32 *)(r6 +44) = r0 391: (18) r1 = map[idx:0]+5584 393: (61) r0 = *(u32 *)(r1 +0) 394: (63) *(u32 *)(r6 +24) = r0 395: (b7) r0 = 0 396: (95) exit err 0 // the loader program was loaded and executed successfully (null) func#0 @0 ... // CO-RE in the kernel logs: CO-RE relocating STRUCT file: found target candidate [500] prog '': relo #0: kind <byte_off> (0), spec is [8] STRUCT file.f_path (0:1 @ offset 16) prog '': relo #0: matching candidate #0 [500] STRUCT file.f_path (0:1 @ offset 16) prog '': relo #0: patched insn #15 (ALU/ALU64) imm 16 -> 16 vmlinux_cand_cache:[11]file(500), module_cand_cache: ... // verifier logs when it was checking test_d_path.o program: R1 type=ctx expected=fp 0: R1=ctx(id=0,off=0,imm=0) R10=fp0 ; int BPF_PROG(prog_close, struct file *file, void *id) 0: (79) r6 = *(u64 *)(r1 +0) func 'filp_close' arg0 has btf_id 500 type STRUCT 'file' 1: R1=ctx(id=0,off=0,imm=0) R6_w=ptr_file(id=0,off=0,imm=0) R10=fp0 ; pid_t pid = bpf_get_current_pid_tgid() >> 32; 1: (85) call bpf_get_current_pid_tgid#14 ... // if there are multiple programs being loaded by the loader program ... // only the last program in the elf file will be printed, since ... // the same verifier log_buf is used for all PROG_LOAD commands. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211204194623.27779-1-alexei.starovoitov@gmail.com
* bpf: Disallow BPF_LOG_KERNEL log level for bpf(BPF_BTF_LOAD)Hou Tao2021-12-043-5/+11
| | | | | | | | | | | | | | BPF_LOG_KERNEL is only used internally, so disallow bpf_btf_load() to set log level as BPF_LOG_KERNEL. The same checking has already been done in bpf_check(), so factor out a helper to check the validity of log attributes and use it in both places. Fixes: 8580ac9404f6 ("bpf: Process in-kernel BTF") Signed-off-by: Hou Tao <houtao1@huawei.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20211203053001.740945-1-houtao1@huawei.com
* bpf: Fix the test_task_vma selftest to support output shorter than 1 kBMaxim Mikityanskiy2021-12-031-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The test for bpf_iter_task_vma assumes that the output will be longer than 1 kB, as the comment above the loop says. Due to this assumption, the loop becomes infinite if the output turns to be shorter than 1 kB. The return value of read_fd_into_buffer is 0 when the end of file was reached, and len isn't being increased any more. This commit adds a break on EOF to handle short output correctly. For the reference, this is the contents that I get when running test_progs under vmtest.sh, and it's shorter than 1 kB: 00400000-00401000 r--p 00000000 fe:00 25867 /root/bpf/test_progs 00401000-00674000 r-xp 00001000 fe:00 25867 /root/bpf/test_progs 00674000-0095f000 r--p 00274000 fe:00 25867 /root/bpf/test_progs 0095f000-00983000 r--p 0055e000 fe:00 25867 /root/bpf/test_progs 00983000-00a8a000 rw-p 00582000 fe:00 25867 /root/bpf/test_progs 00a8a000-0484e000 rw-p 00000000 00:00 0 7f6c64000000-7f6c64021000 rw-p 00000000 00:00 0 7f6c64021000-7f6c68000000 ---p 00000000 00:00 0 7f6c6ac8f000-7f6c6ac90000 r--s 00000000 00:0d 8032 anon_inode:bpf-map 7f6c6ac90000-7f6c6ac91000 ---p 00000000 00:00 0 7f6c6ac91000-7f6c6b491000 rw-p 00000000 00:00 0 7f6c6b491000-7f6c6b492000 r--s 00000000 00:0d 8032 anon_inode:bpf-map 7f6c6b492000-7f6c6b493000 rw-s 00000000 00:0d 8032 anon_inode:bpf-map 7ffc1e23d000-7ffc1e25e000 rw-p 00000000 00:00 0 7ffc1e3b8000-7ffc1e3bc000 r--p 00000000 00:00 0 7ffc1e3bc000-7ffc1e3bd000 r-xp 00000000 00:00 0 7fffffffe000-7ffffffff000 --xp 00000000 00:00 0 Fixes: e8168840e16c ("selftests/bpf: Add test for bpf_iter_task_vma") Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20211130181811.594220-1-maximmi@nvidia.com
* libbpf: Reduce bpf_core_apply_relo_insn() stack usage.Alexei Starovoitov2021-12-034-46/+61
| | | | | | | | | | Reduce bpf_core_apply_relo_insn() stack usage and bump BPF_CORE_SPEC_MAX_LEN limit back to 64. Fixes: 29db4bea1d10 ("bpf: Prepare relo_core.c for kernel duty.") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211203182836.16646-1-alexei.starovoitov@gmail.com
* perf: Mute libbpf API deprecations temporarilyAndrii Nakryiko2021-12-032-0/+7
| | | | | | | | | | | | | | | | | | | | Libbpf development version was bumped to 0.7 in c93faaaf2f67 ("libbpf: Deprecate bpf_prog_load_xattr() API"), activating a bunch of previously scheduled deprecations. Most APIs are pretty straightforward to replace with newer APIs, but perf has a complicated mixed setup with libbpf used both as static and shared configurations, which makes it non-trivial to migrate the APIs. Further, bpf_program__set_prep() needs more involved refactoring, which will require help from Arnaldo and/or Jiri. So for now, mute deprecation warnings and work on migrating perf off of deprecated APIs separately with the input from owners of the perf tool. Fixes: c93faaaf2f67 ("libbpf: Deprecate bpf_prog_load_xattr() API") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211203004640.2455717-1-andrii@kernel.org
* Merge branch 'Deprecate bpf_prog_load_xattr() API'Alexei Starovoitov2021-12-0337-202/+293
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Andrii Nakryiko says: ==================== Few lines in the last patch to mark bpf_prog_load_xattr() deprecated required a decent amount of clean ups in all the other patches. samples/bpf is big part of the clean up. This patch set also bumps libbpf version to 0.7, as libbpf v0.6 release will be cut shortly. ==================== Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * libbpf: Deprecate bpf_prog_load_xattr() APIAndrii Nakryiko2021-12-032-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | bpf_prog_load_xattr() is high-level API that's named as a low-level BPF_PROG_LOAD wrapper APIs, but it actually operates on struct bpf_object. It's badly and confusingly misnamed as it will load all the progs insige bpf_object, returning prog_fd of the very first BPF program. It also has a bunch of ad-hoc things like log_level override, map_ifindex auto-setting, etc. All this can be expressed more explicitly and cleanly through existing libbpf APIs. This patch marks bpf_prog_load_xattr() for deprecation in libbpf v0.8 ([0]). [0] Closes: https://github.com/libbpf/libbpf/issues/308 Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-10-andrii@kernel.org
| * samples/bpf: Get rid of deprecated libbpf API usesAndrii Nakryiko2021-12-0315-57/+108
| | | | | | | | | | | | | | | | | | | | | | Replace deprecated APIs with new ones. Also mute source code using deprecated AF_XDP (xsk.h). Figuring out what to do with all the AF_XDP stuff is a separate problem that should be solved with its own set of changes. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-9-andrii@kernel.org
| * samples/bpf: Clean up samples/bpf build failesAndrii Nakryiko2021-12-034-21/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Remove xdp_samples_user.o rule redefinition which generates Makefile warning and instead override TPROGS_CFLAGS. This seems to work fine when building inside selftests/bpf. That was one big head-scratcher before I found that generic Makefile.target hid this surprising specialization for for xdp_samples_user.o. Main change is to use actual locally installed libbpf headers. Also drop printk macro re-definition (not even used!). Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-8-andrii@kernel.org
| * selftests/bpf: Remove all the uses of deprecated bpf_prog_load_xattr()Andrii Nakryiko2021-12-039-107/+119
| | | | | | | | | | | | | | | | | | | | Migrate all the selftests that were still using bpf_prog_load_xattr(). Few are converted to skeleton, others will use bpf_object__open_file() API. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-7-andrii@kernel.org
| * selftests/bpf: Mute xdpxceiver.c's deprecation warningsAndrii Nakryiko2021-12-031-0/+6
| | | | | | | | | | | | | | | | | | | | xdpxceiver.c is using AF_XDP APIs that are deprecated starting from libbpf 0.7. Until we migrate the test to libxdp or solve this issue in some other way, mute deprecation warnings within xdpxceiver.c. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-6-andrii@kernel.org
| * selftests/bpf: Remove recently reintroduced legacy btf__dedup() useAndrii Nakryiko2021-12-031-2/+2
| | | | | | | | | | | | | | | | | | We've added one extra patch that added back the use of legacy btf__dedup() variant. Clean that up. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-5-andrii@kernel.org
| * bpftool: Migrate off of deprecated bpf_create_map_xattr() APIAndrii Nakryiko2021-12-031-10/+13
| | | | | | | | | | | | | | | | Switch to bpf_map_create() API instead. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-4-andrii@kernel.org
| * libbpf: Add API to get/set log_level at per-program levelAndrii Nakryiko2021-12-034-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | Add bpf_program__set_log_level() and bpf_program__log_level() to fetch and adjust log_level sent during BPF_PROG_LOAD command. This allows to selectively request more or less verbose output in BPF verifier log. Also bump libbpf version to 0.7 and make these APIs the first in v0.7. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-3-andrii@kernel.org
| * libbpf: Use __u32 fields in bpf_map_create_optsAndrii Nakryiko2021-12-031-4/+4
|/ | | | | | | | | | Corresponding Linux UAPI struct uses __u32, not int, so keep it consistent. Fixes: 992c4225419a ("libbpf: Unify low-level map creation APIs w/ new bpf_map_create()") Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211201232824.3166325-2-andrii@kernel.org
* selftests/bpf: Update test names for xchg and cmpxchgPaul E. McKenney2021-12-021-2/+2
| | | | | | | | | | The test_cmpxchg() and test_xchg() functions say "test_run add". Therefore, make them say "test_run cmpxchg" and "test_run xchg", respectively. Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201005030.GA3071525@paulmck-ThinkPad-P17-Gen-1
* selftests/bpf: Build testing_helpers.o out of treeJean-Philippe Brucker2021-12-021-18/+22
| | | | | | | | | | | | | | | | Add $(OUTPUT) prefix to testing_helpers.o, so it can be built out of tree when necessary. At the moment, in addition to being built in-tree even when out-of-tree is required, testing_helpers.o is not built with the right recipe when cross-building. For consistency the other helpers, cgroup_helpers and trace_helpers, can also be passed as objects instead of source. Use *_HELPERS variable to keep the Makefile readable. Fixes: f87c1930ac29 ("selftests/bpf: Merge test_stub.c into testing_helpers.c") Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201145101.823159-1-jean-philippe@linaro.org
* Merge branch 'bpf: CO-RE support in the kernel'Andrii Nakryiko2021-12-0225-228/+1179
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Alexei Starovoitov says: ==================== From: Alexei Starovoitov <ast@kernel.org> v4->v5: . Reduce number of memory allocations in candidate cache logic . Fix couple UAF issues . Add Andrii's patch to cleanup struct bpf_core_cand . More thorough tests . Planned followups: - support -v in lskel - move struct bpf_core_spec out of bpf_core_apply_relo_insn to reduce stack usage - implement bpf_core_types_are_compat v3->v4: . complete refactor of find candidates logic. Now it has small permanent cache. . Fix a bug in gen_loader related to attach_kind. . Fix BTF log size limit. . More tests. v2->v3: . addressed Andrii's feedback in every patch. New field in union bpf_attr changed from "core_relo" to "core_relos". . added one more test and checkpatch.pl-ed the set. v1->v2: . Refactor uapi to pass 'struct bpf_core_relo' from LLVM into libbpf and further into the kernel instead of bpf_core_apply_relo() bpf helper. Because of this change the CO-RE algorithm has an ability to log error and debug events through the standard bpf verifer log mechanism which was not possible with helper approach. . #define RELO_CORE macro was removed and replaced with btf_member_bit_offset() patch. This set introduces CO-RE support in the kernel. There are several reasons to add such support: 1. It's a step toward signed BPF programs. 2. It allows golang like languages that struggle to adopt libbpf to take advantage of CO-RE powers. 3. Currently the field accessed by 'ldx [R1 + 10]' insn is recognized by the verifier purely based on +10 offset. If R1 points to a union the verifier picks one of the fields at this offset. With CO-RE the kernel can disambiguate the field access. Alexei Starovoitov (16): libbpf: Replace btf__type_by_id() with btf_type_by_id(). bpf: Rename btf_member accessors. bpf: Prepare relo_core.c for kernel duty. bpf: Define enum bpf_core_relo_kind as uapi. bpf: Pass a set of bpf_core_relo-s to prog_load command. bpf: Adjust BTF log size limit. bpf: Add bpf_core_add_cands() and wire it into bpf_core_apply_relo_insn(). libbpf: Use CO-RE in the kernel in light skeleton. libbpf: Support init of inner maps in light skeleton. libbpf: Clean gen_loader's attach kind. selftests/bpf: Add lskel version of kfunc test. selftests/bpf: Improve inner_map test coverage. selftests/bpf: Convert map_ptr_kern test to use light skeleton. selftests/bpf: Additional test for CO-RE in the kernel. selftests/bpf: Revert CO-RE removal in test_ksyms_weak. selftests/bpf: Add CO-RE relocations to verifier scale test. ==================== Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
| * selftests/bpf: Add CO-RE relocations to verifier scale test.Alexei Starovoitov2021-12-021-2/+2
| | | | | | | | | | | | | | | | Add 182 CO-RE relocations to verifier scale test. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-18-alexei.starovoitov@gmail.com
| * selftests/bpf: Revert CO-RE removal in test_ksyms_weak.Alexei Starovoitov2021-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | | | The commit 087cba799ced ("selftests/bpf: Add weak/typeless ksym test for light skeleton") added test_ksyms_weak to light skeleton testing, but remove CO-RE access. Revert that part of commit, since light skeleton can use CO-RE in the kernel. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-17-alexei.starovoitov@gmail.com
| * selftests/bpf: Additional test for CO-RE in the kernel.Alexei Starovoitov2021-12-023-1/+119
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a test where randmap() function is appended to three different bpf programs. That action checks struct bpf_core_relo replication logic and offset adjustment in gen loader part of libbpf. Fourth bpf program has 360 CO-RE relocations from vmlinux, bpf_testmod, and non-existing type. It tests candidate cache logic. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-16-alexei.starovoitov@gmail.com
| * selftests/bpf: Convert map_ptr_kern test to use light skeleton.Alexei Starovoitov2021-12-022-10/+9
| | | | | | | | | | | | | | | | | | | | To exercise CO-RE in the kernel further convert map_ptr_kern test to light skeleton. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-15-alexei.starovoitov@gmail.com
| * selftests/bpf: Improve inner_map test coverage.Alexei Starovoitov2021-12-021-2/+14
| | | | | | | | | | | | | | | | | | Check that hash and array inner maps are properly initialized. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-14-alexei.starovoitov@gmail.com
| * selftests/bpf: Add lskel version of kfunc test.Alexei Starovoitov2021-12-022-1/+25
| | | | | | | | | | | | | | | | | | Add light skeleton version of kfunc_call_test_subprog test. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-13-alexei.starovoitov@gmail.com
| * libbpf: Clean gen_loader's attach kind.Alexei Starovoitov2021-12-021-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | The gen_loader has to clear attach_kind otherwise the programs without attach_btf_id will fail load if they follow programs with attach_btf_id. Fixes: 67234743736a ("libbpf: Generate loader program out of BPF ELF file.") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-12-alexei.starovoitov@gmail.com
| * libbpf: Support init of inner maps in light skeleton.Alexei Starovoitov2021-12-023-3/+31
| | | | | | | | | | | | | | | | | | Add ability to initialize inner maps in light skeleton. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-11-alexei.starovoitov@gmail.com
| * libbpf: Use CO-RE in the kernel in light skeleton.Alexei Starovoitov2021-12-023-33/+120
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without lskel the CO-RE relocations are processed by libbpf before any other work is done. Instead, when lskel is needed, remember relocation as RELO_CORE kind. Then when loader prog is generated for a given bpf program pass CO-RE relos of that program to gen loader via bpf_gen__record_relo_core(). The gen loader will remember them as-is and pass it later as-is into the kernel. The normal libbpf flow is to process CO-RE early before call relos happen. In case of gen_loader the core relos have to be added to other relos to be copied together when bpf static function is appended in different places to other main bpf progs. During the copy the append_subprog_relos() will adjust insn_idx for normal relos and for RELO_CORE kind too. When that is done each struct reloc_desc has good relos for specific main prog. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-10-alexei.starovoitov@gmail.com
| * bpf: Add bpf_core_add_cands() and wire it into bpf_core_apply_relo_insn().Alexei Starovoitov2021-12-021-1/+345
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Given BPF program's BTF root type name perform the following steps: . search in vmlinux candidate cache. . if (present in cache and candidate list >= 1) return candidate list. . do a linear search through kernel BTFs for possible candidates. . regardless of number of candidates found populate vmlinux cache. . if (candidate list >= 1) return candidate list. . search in module candidate cache. . if (present in cache) return candidate list (even if list is empty). . do a linear search through BTFs of all kernel modules collecting candidates from all of them. . regardless of number of candidates found populate module cache. . return candidate list. Then wire the result into bpf_core_apply_relo_insn(). When BPF program is trying to CO-RE relocate a type that doesn't exist in either vmlinux BTF or in modules BTFs these steps will perform 2 cache lookups when cache is hit. Note the cache doesn't prevent the abuse by the program that might have lots of relocations that cannot be resolved. Hence cond_resched(). CO-RE in the kernel requires CAP_BPF, since BTF loading requires it. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-9-alexei.starovoitov@gmail.com
| * libbpf: Cleanup struct bpf_core_cand.Andrii Nakryiko2021-12-022-15/+17
| | | | | | | | | | | | | | | | | | Remove two redundant fields from struct bpf_core_cand. Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-8-alexei.starovoitov@gmail.com
| * bpf: Adjust BTF log size limit.Alexei Starovoitov2021-12-021-1/+1
| | | | | | | | | | | | | | | | | | | | Make BTF log size limit to be the same as the verifier log size limit. Otherwise tools that progressively increase log size and use the same log for BTF loading and program loading will be hitting hard to debug EINVAL. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-7-alexei.starovoitov@gmail.com
| * bpf: Pass a set of bpf_core_relo-s to prog_load command.Alexei Starovoitov2021-12-027-56/+207
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | struct bpf_core_relo is generated by llvm and processed by libbpf. It's a de-facto uapi. With CO-RE in the kernel the struct bpf_core_relo becomes uapi de-jure. Add an ability to pass a set of 'struct bpf_core_relo' to prog_load command and let the kernel perform CO-RE relocations. Note the struct bpf_line_info and struct bpf_func_info have the same layout when passed from LLVM to libbpf and from libbpf to the kernel except "insn_off" fields means "byte offset" when LLVM generates it. Then libbpf converts it to "insn index" to pass to the kernel. The struct bpf_core_relo's "insn_off" field is always "byte offset". Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-6-alexei.starovoitov@gmail.com
| * bpf: Define enum bpf_core_relo_kind as uapi.Alexei Starovoitov2021-12-025-60/+82
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | enum bpf_core_relo_kind is generated by llvm and processed by libbpf. It's a de-facto uapi. With CO-RE in the kernel the bpf_core_relo_kind values become uapi de-jure. Also rename them with BPF_CORE_ prefix to distinguish from conflicting names in bpf_core_read.h. The enums bpf_field_info_kind, bpf_type_id_kind, bpf_type_info_kind, bpf_enum_value_kind are passing different values from bpf program into llvm. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-5-alexei.starovoitov@gmail.com
| * bpf: Prepare relo_core.c for kernel duty.Alexei Starovoitov2021-12-024-11/+176
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make relo_core.c to be compiled for the kernel and for user space libbpf. Note the patch is reducing BPF_CORE_SPEC_MAX_LEN from 64 to 32. This is the maximum number of nested structs and arrays. For example: struct sample { int a; struct { int b[10]; }; }; struct sample *s = ...; int *y = &s->b[5]; This field access is encoded as "0:1:0:5" and spec len is 4. The follow up patch might bump it back to 64. Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-4-alexei.starovoitov@gmail.com
| * bpf: Rename btf_member accessors.Alexei Starovoitov2021-12-024-19/+19
| | | | | | | | | | | | | | | | | | | | | | | | Rename btf_member_bit_offset() and btf_member_bitfield_size() to avoid conflicts with similarly named helpers in libbpf's btf.h. Rename the kernel helpers, since libbpf helpers are part of uapi. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-3-alexei.starovoitov@gmail.com
| * libbpf: Replace btf__type_by_id() with btf_type_by_id().Alexei Starovoitov2021-12-023-13/+10
|/ | | | | | | | | | | | | | | | | | To prepare relo_core.c to be compiled in the kernel and the user space replace btf__type_by_id with btf_type_by_id. In libbpf btf__type_by_id and btf_type_by_id have different behavior. bpf_core_apply_relo_insn() needs behavior of uapi btf__type_by_id vs internal btf_type_by_id, but type_id range check is already done in bpf_core_apply_relo(), so it's safe to replace it everywhere. The kernel btf_type_by_id() does the check anyway. It doesn't hurt. Suggested-by: Andrii Nakryiko <andrii@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andrii@kernel.org> Acked-by: Andrii Nakryiko <andrii@kernel.org> Link: https://lore.kernel.org/bpf/20211201181040.23337-2-alexei.starovoitov@gmail.com
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