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* Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller2019-12-2762-1881/+5131
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Daniel Borkmann says: ==================== pull-request: bpf-next 2019-12-27 The following pull-request contains BPF updates for your *net-next* tree. We've added 127 non-merge commits during the last 17 day(s) which contain a total of 110 files changed, 6901 insertions(+), 2721 deletions(-). There are three merge conflicts. Conflicts and resolution looks as follows: 1) Merge conflict in net/bpf/test_run.c: There was a tree-wide cleanup c593642c8be0 ("treewide: Use sizeof_field() macro") which gets in the way with b590cb5f802d ("bpf: Switch to offsetofend in BPF_PROG_TEST_RUN"): <<<<<<< HEAD if (!range_is_zero(__skb, offsetof(struct __sk_buff, priority) + sizeof_field(struct __sk_buff, priority), ======= if (!range_is_zero(__skb, offsetofend(struct __sk_buff, priority), >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c There are a few occasions that look similar to this. Always take the chunk with offsetofend(). Note that there is one where the fields differ in here: <<<<<<< HEAD if (!range_is_zero(__skb, offsetof(struct __sk_buff, tstamp) + sizeof_field(struct __sk_buff, tstamp), ======= if (!range_is_zero(__skb, offsetofend(struct __sk_buff, gso_segs), >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Just take the one with offsetofend() /and/ gso_segs. Latter is correct due to 850a88cc4096 ("bpf: Expose __sk_buff wire_len/gso_segs to BPF_PROG_TEST_RUN"). 2) Merge conflict in arch/riscv/net/bpf_jit_comp.c: (I'm keeping Bjorn in Cc here for a double-check in case I got it wrong.) <<<<<<< HEAD if (is_13b_check(off, insn)) return -1; emit(rv_blt(tcc, RV_REG_ZERO, off >> 1), ctx); ======= emit_branch(BPF_JSLT, RV_REG_T1, RV_REG_ZERO, off, ctx); >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Result should look like: emit_branch(BPF_JSLT, tcc, RV_REG_ZERO, off, ctx); 3) Merge conflict in arch/riscv/include/asm/pgtable.h: <<<<<<< HEAD ======= #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) #define BPF_JIT_REGION_END (VMALLOC_END) /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ #define VMEMMAP_SHIFT \ (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) #define VMEMMAP_END (VMALLOC_START - 1) #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) #define vmemmap ((struct page *)VMEMMAP_START) >>>>>>> 7c8dce4b166113743adad131b5a24c4acc12f92c Only take the BPF_* defines from there and move them higher up in the same file. Remove the rest from the chunk. The VMALLOC_* etc defines got moved via 01f52e16b868 ("riscv: define vmemmap before pfn_to_page calls"). Result: [...] #define __S101 PAGE_READ_EXEC #define __S110 PAGE_SHARED_EXEC #define __S111 PAGE_SHARED_EXEC #define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1) #define VMALLOC_END (PAGE_OFFSET - 1) #define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE) #define BPF_JIT_REGION_SIZE (SZ_128M) #define BPF_JIT_REGION_START (PAGE_OFFSET - BPF_JIT_REGION_SIZE) #define BPF_JIT_REGION_END (VMALLOC_END) /* * Roughly size the vmemmap space to be large enough to fit enough * struct pages to map half the virtual address space. Then * position vmemmap directly below the VMALLOC region. */ #define VMEMMAP_SHIFT \ (CONFIG_VA_BITS - PAGE_SHIFT - 1 + STRUCT_PAGE_MAX_SHIFT) #define VMEMMAP_SIZE BIT(VMEMMAP_SHIFT) #define VMEMMAP_END (VMALLOC_START - 1) #define VMEMMAP_START (VMALLOC_START - VMEMMAP_SIZE) [...] Let me know if there are any other issues. Anyway, the main changes are: 1) Extend bpftool to produce a struct (aka "skeleton") tailored and specific to a provided BPF object file. This provides an alternative, simplified API compared to standard libbpf interaction. Also, add libbpf extern variable resolution for .kconfig section to import Kconfig data, from Andrii Nakryiko. 2) Add BPF dispatcher for XDP which is a mechanism to avoid indirect calls by generating a branch funnel as discussed back in bpfconf'19 at LSF/MM. Also, add various BPF riscv JIT improvements, from Björn Töpel. 3) Extend bpftool to allow matching BPF programs and maps by name, from Paul Chaignon. 4) Support for replacing cgroup BPF programs attached with BPF_F_ALLOW_MULTI flag for allowing updates without service interruption, from Andrey Ignatov. 5) Cleanup and simplification of ring access functions for AF_XDP with a bonus of 0-5% performance improvement, from Magnus Karlsson. 6) Enable BPF JITs for x86-64 and arm64 by default. Also, final version of audit support for BPF, from Daniel Borkmann and latter with Jiri Olsa. 7) Move and extend test_select_reuseport into BPF program tests under BPF selftests, from Jakub Sitnicki. 8) Various BPF sample improvements for xdpsock for customizing parameters to set up and benchmark AF_XDP, from Jay Jayatheerthan. 9) Improve libbpf to provide a ulimit hint on permission denied errors. Also change XDP sample programs to attach in driver mode by default, from Toke Høiland-Jørgensen. 10) Extend BPF test infrastructure to allow changing skb mark from tc BPF programs, from Nikita V. Shirokov. 11) Optimize prologue code sequence in BPF arm32 JIT, from Russell King. 12) Fix xdp_redirect_cpu BPF sample to manually attach to tracepoints after libbpf conversion, from Jesper Dangaard Brouer. 13) Minor misc improvements from various others. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
| * bpftool: Make skeleton C code compilable with C++ compilerAndrii Nakryiko2019-12-273-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When auto-generated BPF skeleton C code is included from C++ application, it triggers compilation error due to void * being implicitly casted to whatever target pointer type. This is supported by C, but not C++. To solve this problem, add explicit casts, where necessary. To ensure issues like this are captured going forward, add skeleton usage in test_cpp test. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191226210253.3132060-1-andriin@fb.com
| * bpf: Print error message for bpftool cgroup showHechao Li2019-12-261-17/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, when bpftool cgroup show <path> has an error, no error message is printed. This is confusing because the user may think the result is empty. Before the change: $ bpftool cgroup show /sys/fs/cgroup ID AttachType AttachFlags Name $ echo $? 255 After the change: $ ./bpftool cgroup show /sys/fs/cgroup Error: can't query bpf programs attached to /sys/fs/cgroup: Operation not permitted v2: Rename check_query_cgroup_progs to cgroup_has_attached_progs Signed-off-by: Hechao Li <hechaol@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191224011742.3714301-1-hechaol@fb.com
| * libbpf: Support CO-RE relocations for LDX/ST/STX instructionsAndrii Nakryiko2019-12-261-3/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Clang patch [0] enables emitting relocatable generic ALU/ALU64 instructions (i.e, shifts and arithmetic operations), as well as generic load/store instructions. The former ones are already supported by libbpf as is. This patch adds further support for load/store instructions. Relocatable field offset is encoded in BPF instruction's 16-bit offset section and are adjusted by libbpf based on target kernel BTF. These Clang changes and corresponding libbpf changes allow for more succinct generated BPF code by encoding relocatable field reads as a single ST/LDX/STX instruction. It also enables relocatable access to BPF context. Previously, if context struct (e.g., __sk_buff) was accessed with CO-RE relocations (e.g., due to preserve_access_index attribute), it would be rejected by BPF verifier due to modified context pointer dereference. With Clang patch, such context accesses are both relocatable and have a fixed offset from the point of view of BPF verifier. [0] https://reviews.llvm.org/D71790 Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191223180305.86417-1-andriin@fb.com
| * selftests/bpf: Preserve errno in test_progs CHECK macrosAndrey Ignatov2019-12-211-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's follow-up for discussion [1] CHECK and CHECK_FAIL macros in test_progs.h can affect errno in some circumstances, e.g. if some code accidentally closes stdout. It makes checking errno in patterns like this unreliable: if (CHECK(!bpf_prog_attach_xattr(...), "tag", "msg")) goto err; CHECK_FAIL(errno != ENOENT); , since by CHECK_FAIL time errno could be affected not only by bpf_prog_attach_xattr but by CHECK as well. Fix it by saving and restoring errno in the macros. There is no "Fixes" tag since no problems were discovered yet and it's rather precaution. test_progs was run with this change and no difference was identified. [1] https://lore.kernel.org/bpf/20191219210907.GD16266@rdna-mbp.dhcp.thefacebook.com/ Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191220000511.1684853-1-rdna@fb.com
| * selftests/bpf: Test BPF_F_REPLACE in cgroup_attach_multiAndrey Ignatov2019-12-201-3/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Test replacing a cgroup-bpf program attached with BPF_F_ALLOW_MULTI and possible failure modes: invalid combination of flags, invalid replace_bpf_fd, replacing a non-attachd to specified cgroup program. Example of program replacing: # gdb -q --args ./test_progs --name=cgroup_attach_multi ... Breakpoint 1, test_cgroup_attach_multi () at cgroup_attach_multi.c:227 (gdb) [1]+ Stopped gdb -q --args ./test_progs --name=cgroup_attach_multi # bpftool c s /mnt/cgroup2/cgroup-test-work-dir/cg1 ID AttachType AttachFlags Name 2133 egress multi 2134 egress multi # fg gdb -q --args ./test_progs --name=cgroup_attach_multi (gdb) c Continuing. Breakpoint 2, test_cgroup_attach_multi () at cgroup_attach_multi.c:233 (gdb) [1]+ Stopped gdb -q --args ./test_progs --name=cgroup_attach_multi # bpftool c s /mnt/cgroup2/cgroup-test-work-dir/cg1 ID AttachType AttachFlags Name 2139 egress multi 2134 egress multi Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/7b9b83e8d5fb82e15b034341bd40b6fb2431eeba.1576741281.git.rdna@fb.com
| * selftests/bpf: Convert test_cgroup_attach to prog_testsAndrey Ignatov2019-12-206-574/+498
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Convert test_cgroup_attach to prog_tests. This change does a lot of things but in many cases it's pretty expensive to separate them, so they go in one commit. Nevertheless the logic is ketp as is and changes made are just moving things around, simplifying them (w/o changing the meaning of the tests) and making prog_tests compatible: * split the 3 tests in the file into 3 separate files in prog_tests/; * rename the test functions to test_<file_base_name>; * remove unused includes, constants, variables and functions from every test; * replace `if`-s with or `if (CHECK())` where additional context should be logged and with `if (CHECK_FAIL())` where line number is enough; * switch from `log_err()` to logging via `CHECK()`; * replace `assert`-s with `CHECK_FAIL()` to avoid crashing the whole test_progs if one assertion fails; * replace cgroup_helpers with test__join_cgroup() in cgroup_attach_override only, other tests need more fine-grained control for cgroup creation/deletion so cgroup_helpers are still used there; * simplify cgroup_attach_autodetach by switching to easiest possible program since this test doesn't really need such a complicated program as cgroup_attach_multi does; * remove test_cgroup_attach.c itself. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/0ff19cc64d2dc5cf404349f07131119480e10e32.1576741281.git.rdna@fb.com
| * libbpf: Introduce bpf_prog_attach_xattrAndrey Ignatov2019-12-203-1/+28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a new bpf_prog_attach_xattr function that, in addition to program fd, target fd and attach type, accepts an extendable struct bpf_prog_attach_opts. bpf_prog_attach_opts relies on DECLARE_LIBBPF_OPTS macro to maintain backward and forward compatibility and has the following "optional" attach attributes: * existing attach_flags, since it's not required when attaching in NONE mode. Even though it's quite often used in MULTI and OVERRIDE mode it seems to be a good idea to reduce number of arguments to bpf_prog_attach_xattr; * newly introduced attribute of BPF_PROG_ATTACH command: replace_prog_fd that is fd of previously attached cgroup-bpf program to replace if BPF_F_REPLACE flag is used. The new function is named to be consistent with other xattr-functions (bpf_prog_test_run_xattr, bpf_create_map_xattr, bpf_load_program_xattr). The struct bpf_prog_attach_opts is supposed to be used with DECLARE_LIBBPF_OPTS macro. Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/bd6e0732303eb14e4b79cb128268d9e9ad6db208.1576741281.git.rdna@fb.com
| * bpf: Support replacing cgroup-bpf program in MULTI modeAndrey Ignatov2019-12-201-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The common use-case in production is to have multiple cgroup-bpf programs per attach type that cover multiple use-cases. Such programs are attached with BPF_F_ALLOW_MULTI and can be maintained by different people. Order of programs usually matters, for example imagine two egress programs: the first one drops packets and the second one counts packets. If they're swapped the result of counting program will be different. It brings operational challenges with updating cgroup-bpf program(s) attached with BPF_F_ALLOW_MULTI since there is no way to replace a program: * One way to update is to detach all programs first and then attach the new version(s) again in the right order. This introduces an interruption in the work a program is doing and may not be acceptable (e.g. if it's egress firewall); * Another way is attach the new version of a program first and only then detach the old version. This introduces the time interval when two versions of same program are working, what may not be acceptable if a program is not idempotent. It also imposes additional burden on program developers to make sure that two versions of their program can co-exist. Solve the problem by introducing a "replace" mode in BPF_PROG_ATTACH command for cgroup-bpf programs being attached with BPF_F_ALLOW_MULTI flag. This mode is enabled by newly introduced BPF_F_REPLACE attach flag and bpf_attr.replace_bpf_fd attribute to pass fd of the old program to replace That way user can replace any program among those attached with BPF_F_ALLOW_MULTI flag without the problems described above. Details of the new API: * If BPF_F_REPLACE is set but replace_bpf_fd doesn't have valid descriptor of BPF program, BPF_PROG_ATTACH will return corresponding error (EINVAL or EBADF). * If replace_bpf_fd has valid descriptor of BPF program but such a program is not attached to specified cgroup, BPF_PROG_ATTACH will return ENOENT. BPF_F_REPLACE is introduced to make the user intent clear, since replace_bpf_fd alone can't be used for this (its default value, 0, is a valid fd). BPF_F_REPLACE also makes it possible to extend the API in the future (e.g. add BPF_F_BEFORE and BPF_F_AFTER if needed). Signed-off-by: Andrey Ignatov <rdna@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Andrii Narkyiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/30cd850044a0057bdfcaaf154b7d2f39850ba813.1576741281.git.rdna@fb.com
| * libbpf: Fix another __u64 printf warningAndrii Nakryiko2019-12-191-2/+2
| | | | | | | | | | | | | | | | | | | | Fix yet another printf warning for %llu specifier on ppc64le. This time size_t casting won't work, so cast to verbose `unsigned long long`. Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191219052103.3515-1-andriin@fb.com
| * libbpf: Fix printing of ulimit valueToke Høiland-Jørgensen2019-12-191-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Naresh pointed out that libbpf builds fail on 32-bit architectures because rlimit.rlim_cur is defined as 'unsigned long long' on those architectures. Fix this by using %zu in printf and casting to size_t. Fixes: dc3a2d254782 ("libbpf: Print hint about ulimit when getting permission denied error") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191219090236.905059-1-toke@redhat.com
| * selftests/bpf: Fix test_attach_probeAlexei Starovoitov2019-12-191-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Fix two issues in test_attach_probe: 1. it was not able to parse /proc/self/maps beyond the first line, since %s means parse string until white space. 2. offset has to be accounted for otherwise uprobed address is incorrect. Fixes: 1e8611bbdfc9 ("selftests/bpf: add kprobe/uprobe selftests") Signed-off-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191219020442.1922617-1-ast@kernel.org
| * libbpf: Add missing newline in opts validation macroToke Høiland-Jørgensen2019-12-191-1/+1
| | | | | | | | | | | | | | | | | | The error log output in the opts validation macro was missing a newline. Fixes: 2ce8450ef5a3 ("libbpf: add bpf_object__open_{file, mem} w/ extensible opts") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191219120714.928380-1-toke@redhat.com
| * riscv, bpf: Add missing uapi header for BPF_PROG_TYPE_PERF_EVENT programsBjörn Töpel2019-12-191-0/+2
| | | | | | | | | | | | | | | | | | | | Add missing uapi header the BPF_PROG_TYPE_PERF_EVENT programs by exporting struct user_regs_struct instead of struct pt_regs which is in-kernel only. Signed-off-by: Björn Töpel <bjorn.topel@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216091343.23260-9-bjorn.topel@gmail.com
| * libbpf: BTF is required when externs are presentAndrii Nakryiko2019-12-191-1/+2
| | | | | | | | | | | | | | | | BTF is required to get type information about extern variables. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191219002837.3074619-4-andriin@fb.com
| * libbpf: Allow to augment system Kconfig through extra optional configAndrii Nakryiko2019-12-193-112/+132
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Instead of all or nothing approach of overriding Kconfig file location, allow to extend it with extra values and override chosen subset of values though optional user-provided extra config, passed as a string through open options' .kconfig option. If same config key is present in both user-supplied config and Kconfig, user-supplied one wins. This allows applications to more easily test various conditions despite host kernel's real configuration. If all of BPF object's __kconfig externs are satisfied from user-supplied config, system Kconfig won't be read at all. Simplify selftests by not needing to create temporary Kconfig files. Suggested-by: Alexei Starovoitov <ast@fb.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191219002837.3074619-3-andriin@fb.com
| * libbpf: Put Kconfig externs into .kconfig sectionAndrii Nakryiko2019-12-196-48/+60
| | | | | | | | | | | | | | | | | | | | Move Kconfig-provided externs into custom .kconfig section. Add __kconfig into bpf_helpers.h for user convenience. Update selftests accordingly. Suggested-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191219002837.3074619-2-andriin@fb.com
| * libbpf: Add bpf_link__disconnect() API to preserve underlying BPF resourceAndrii Nakryiko2019-12-193-10/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are cases in which BPF resource (program, map, etc) has to outlive userspace program that "installed" it in the system in the first place. When BPF program is attached, libbpf returns bpf_link object, which is supposed to be destroyed after no longer necessary through bpf_link__destroy() API. Currently, bpf_link destruction causes both automatic detachment and frees up any resources allocated to for bpf_link in-memory representation. This is inconvenient for the case described above because of coupling of detachment and resource freeing. This patch introduces bpf_link__disconnect() API call, which marks bpf_link as disconnected from its underlying BPF resouces. This means that when bpf_link is destroyed later, all its memory resources will be freed, but BPF resource itself won't be detached. This design allows to follow strict and resource-leak-free design by default, while giving easy and straightforward way for user code to opt for keeping BPF resource attached beyond lifetime of a bpf_link. For some BPF programs (i.e., FS-based tracepoints, kprobes, raw tracepoint, etc), user has to make sure to pin BPF program to prevent kernel to automatically detach it on process exit. This should typically be achived by pinning BPF program (or map in some cases) in BPF FS. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191218225039.2668205-1-andriin@fb.com
| * bpf: Allow to change skb mark in test_runNikita V. Shirokov2019-12-192-0/+6
| | | | | | | | | | | | | | | | | | | | allow to pass skb's mark field into bpf_prog_test_run ctx for BPF_PROG_TYPE_SCHED_CLS prog type. that would allow to test bpf programs which are doing decision based on this field Signed-off-by: Nikita V. Shirokov <tehnerd@tehnerd.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
| * bpftool: Work-around rst2man conversion bugAndrii Nakryiko2019-12-191-7/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Work-around what appears to be a bug in rst2man convertion tool, used to create man pages out of reStructureText-formatted documents. If text line starts with dot, rst2man will put it in resulting man file verbatim. This seems to cause man tool to interpret it as a directive/command (e.g., `.bs`), and subsequently not render entire line because it's unrecognized one. Enclose '.xxx' words in extra formatting to work around. Fixes: cb21ac588546 ("bpftool: Add gen subcommand manpage") Reported-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com Link: https://lore.kernel.org/bpf/20191218221707.2552199-1-andriin@fb.com
| * bpftool: Simplify format string to not use positional argsAndrii Nakryiko2019-12-191-2/+2
| | | | | | | | | | | | | | | | | | | | | | Change format string referring to just single argument out of two available. Some versions of libc can reject such format string. Reported-by: Nikita Shirokov <tehnerd@tehnerd.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191218214314.2403729-1-andriin@fb.com
| * bpftool: Add gen subcommand manpageAndrii Nakryiko2019-12-182-1/+306
| | | | | | | | | | | | | | | | | | | | | | Add bpftool-gen.rst describing skeleton on the high level. Also include a small, but complete, example BPF app (BPF side, userspace side, generated skeleton) in example section to demonstrate skeleton API and its usage. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191218052552.2915188-4-andriin@fb.com
| * libbpf: Remove BPF_EMBED_OBJ macro from libbpf.hAndrii Nakryiko2019-12-181-35/+0
| | | | | | | | | | | | | | | | | | | | | | | | Drop BPF_EMBED_OBJ and struct bpf_embed_data now that skeleton automatically embeds contents of its source object file. While BPF_EMBED_OBJ is useful independently of skeleton, we are currently don't have any use cases utilizing it, so let's remove them until/if we need it. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191218052552.2915188-3-andriin@fb.com
| * bpftool, selftests/bpf: Embed object file inside skeletonAndrii Nakryiko2019-12-189-119/+154
| | | | | | | | | | | | | | | | | | | | | | | | | | Embed contents of BPF object file used for BPF skeleton generation inside skeleton itself. This allows to keep BPF object file and its skeleton in sync at all times, and simpifies skeleton instantiation. Also switch existing selftests to not require BPF_EMBED_OBJ anymore. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191218052552.2915188-2-andriin@fb.com
| * libbpf: Reduce log level for custom section namesAndrii Nakryiko2019-12-181-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Libbpf is trying to recognize BPF program type based on its section name during bpf_object__open() phase. This is not strictly enforced and user code has ability to specify/override correct BPF program type after open. But if BPF program is using custom section name, libbpf will still emit warnings, which can be quite annoying to users. This patch reduces log level of information messages emitted by libbpf if section name is not canonical. User can still get a list of all supported section names as debug-level message. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191217234228.1739308-1-andriin@fb.com
| * libbpf: Fix libbpf_common.h when installing libbpf through 'make install'Toke Høiland-Jørgensen2019-12-182-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes two issues with the newly introduced libbpf_common.h file: - The header failed to include <string.h> for the definition of memset() - The new file was not included in the install_headers rule in the Makefile Both of these issues cause breakage when installing libbpf with 'make install' and trying to use it in applications. Fixes: 544402d4b493 ("libbpf: Extract common user-facing helpers") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191217112810.768078-1-toke@redhat.com
| * selftests/bpf: More succinct Makefile outputAndrii Nakryiko2019-12-181-0/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Similarly to bpftool/libbpf output, make selftests/bpf output succinct per-item output line. Output is roughly as follows: $ make ... CLANG-LLC [test_maps] pyperf600.o CLANG-LLC [test_maps] strobemeta.o CLANG-LLC [test_maps] pyperf100.o EXTRA-OBJ [test_progs] cgroup_helpers.o EXTRA-OBJ [test_progs] trace_helpers.o BINARY test_align BINARY test_verifier_log GEN-SKEL [test_progs] fexit_bpf2bpf.skel.h GEN-SKEL [test_progs] test_global_data.skel.h GEN-SKEL [test_progs] sendmsg6_prog.skel.h ... To see the actual command invocation, verbose mode can be turned on with V=1 argument: $ make V=1 ... very verbose output ... Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191217061425.2346359-1-andriin@fb.com
| * libbpf: Add zlib as a dependency in pkg-config templateAndrii Nakryiko2019-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | List zlib as another dependency of libbpf in pkg-config template. Verified it is correctly resolved to proper -lz flag: $ make DESTDIR=/tmp/libbpf-install install $ pkg-config --libs /tmp/libbpf-install/usr/local/lib64/pkgconfig/libbpf.pc -L/usr/local/lib64 -lbpf $ pkg-config --libs --static /tmp/libbpf-install/usr/local/lib64/pkgconfig/libbpf.pc -L/usr/local/lib64 -lbpf -lelf -lz Fixes: 166750bc1dd2 ("libbpf: Support libbpf-provided extern variables") Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Yonghong Song <yhs@fb.com> Cc: Luca Boccassi <bluca@debian.org> Link: https://lore.kernel.org/bpf/20191216183830.3972964-1-andriin@fb.com
| * libbpf: Print hint about ulimit when getting permission denied errorToke Høiland-Jørgensen2019-12-161-0/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Probably the single most common error newcomers to XDP are stumped by is the 'permission denied' error they get when trying to load their program and 'ulimit -l' is set too low. For examples, see [0], [1]. Since the error code is UAPI, we can't change that. Instead, this patch adds a few heuristics in libbpf and outputs an additional hint if they are met: If an EPERM is returned on map create or program load, and geteuid() shows we are root, and the current RLIMIT_MEMLOCK is not infinity, we output a hint about raising 'ulimit -l' as an additional log line. [0] https://marc.info/?l=xdp-newbies&m=157043612505624&w=2 [1] https://github.com/xdp-project/xdp-tutorial/issues/86 Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Jesper Dangaard Brouer <brouer@redhat.com> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20191216181204.724953-1-toke@redhat.com
| * bpftool: Fix compilation warning on shadowed variablePaul Chaignon2019-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | The ident variable has already been declared at the top of the function and doesn't need to be re-declared. Fixes: 985ead416df39 ("bpftool: Add skeleton codegen command") Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://lore.kernel.org/bpf/20191216112733.GA28366@Omicron
| * libbpf: Fix build by renaming variablesPrashant Bhole2019-12-161-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In btf__align_of() variable name 't' is shadowed by inner block declaration of another variable with same name. Patch renames variables in order to fix it. CC sharedobjs/btf.o btf.c: In function ‘btf__align_of’: btf.c:303:21: error: declaration of ‘t’ shadows a previous local [-Werror=shadow] 303 | int i, align = 1, t; | ^ btf.c:283:25: note: shadowed declaration is here 283 | const struct btf_type *t = btf__type_by_id(btf, id); | Fixes: 3d208f4ca111 ("libbpf: Expose btf__align_of() API") Signed-off-by: Prashant Bhole <prashantbhole.linux@gmail.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Tested-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20191216082738.28421-1-prashantbhole.linux@gmail.com
| * selftests/bpf: Add flexible array relocation testsAndrii Nakryiko2019-12-166-4/+56
| | | | | | | | | | | | | | | | Add few tests validation CO-RE relocation handling of flexible array accesses. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191215070844.1014385-3-andriin@fb.com
| * libbpf: Support flexible arrays in CO-REAndrii Nakryiko2019-12-161-5/+29
| | | | | | | | | | | | | | | | | | | | | | | | Some data stuctures in kernel are defined with either zero-sized array or flexible (dimensionless) array at the end of a struct. Actual data of such array follows in memory immediately after the end of that struct, forming its variable-sized "body" of elements. Support such access pattern in CO-RE relocation handling. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191215070844.1014385-2-andriin@fb.com
| * selftests/bpf: Add tests for libbpf-provided externsAndrii Nakryiko2019-12-164-1/+283
| | | | | | | | | | | | | | | | | | | | | | | | Add a set of tests validating libbpf-provided extern variables. One crucial feature that's tested is dead code elimination together with using invalid BPF helper. CONFIG_MISSING is not supposed to exist and should always be specified by libbpf as zero, which allows BPF verifier to correctly do branch pruning and not fail validation, when invalid BPF helper is called from dead if branch. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-5-andriin@fb.com
| * bpftool: Generate externs datasec in BPF skeletonAndrii Nakryiko2019-12-162-5/+9
| | | | | | | | | | | | | | | | | | | | | | Add support for generation of mmap()-ed read-only view of libbpf-provided extern variables. As externs are not supposed to be provided by user code (that's what .data, .bss, and .rodata is for), don't mmap() it initially. Only after skeleton load is performed, map .extern contents as read-only memory. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-4-andriin@fb.com
| * libbpf: Support libbpf-provided extern variablesAndrii Nakryiko2019-12-167-65/+727
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for extern variables, provided to BPF program by libbpf. Currently the following extern variables are supported: - LINUX_KERNEL_VERSION; version of a kernel in which BPF program is executing, follows KERNEL_VERSION() macro convention, can be 4- and 8-byte long; - CONFIG_xxx values; a set of values of actual kernel config. Tristate, boolean, strings, and integer values are supported. Set of possible values is determined by declared type of extern variable. Supported types of variables are: - Tristate values. Are represented as `enum libbpf_tristate`. Accepted values are **strictly** 'y', 'n', or 'm', which are represented as TRI_YES, TRI_NO, or TRI_MODULE, respectively. - Boolean values. Are represented as bool (_Bool) types. Accepted values are 'y' and 'n' only, turning into true/false values, respectively. - Single-character values. Can be used both as a substritute for bool/tristate, or as a small-range integer: - 'y'/'n'/'m' are represented as is, as characters 'y', 'n', or 'm'; - integers in a range [-128, 127] or [0, 255] (depending on signedness of char in target architecture) are recognized and represented with respective values of char type. - Strings. String values are declared as fixed-length char arrays. String of up to that length will be accepted and put in first N bytes of char array, with the rest of bytes zeroed out. If config string value is longer than space alloted, it will be truncated and warning message emitted. Char array is always zero terminated. String literals in config have to be enclosed in double quotes, just like C-style string literals. - Integers. 8-, 16-, 32-, and 64-bit integers are supported, both signed and unsigned variants. Libbpf enforces parsed config value to be in the supported range of corresponding integer type. Integers values in config can be: - decimal integers, with optional + and - signs; - hexadecimal integers, prefixed with 0x or 0X; - octal integers, starting with 0. Config file itself is searched in /boot/config-$(uname -r) location with fallback to /proc/config.gz, unless config path is specified explicitly through bpf_object_open_opts' kernel_config_path option. Both gzipped and plain text formats are supported. Libbpf adds explicit dependency on zlib because of this, but this shouldn't be a problem, given libelf already depends on zlib. All detected extern variables, are put into a separate .extern internal map. It, similarly to .rodata map, is marked as read-only from BPF program side, as well as is frozen on load. This allows BPF verifier to track extern values as constants and perform enhanced branch prediction and dead code elimination. This can be relied upon for doing kernel version/feature detection and using potentially unsupported field relocations or BPF helpers in a CO-RE-based BPF program, while still having a single version of BPF program running on old and new kernels. Selftests are validating this explicitly for unexisting BPF helper. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-3-andriin@fb.com
| * libbpf: Extract internal map names into constantsAndrii Nakryiko2019-12-161-9/+14
| | | | | | | | | | | | | | | | Instead of duplicating string literals, keep them in one place and consistent. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014710.3449601-2-andriin@fb.com
| * bpftool: Add `gen skeleton` BASH completionsAndrii Nakryiko2019-12-161-0/+11
| | | | | | | | | | | | | | | | | | | | Add BASH completions for gen sub-command. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Cc: Quentin Monnet <quentin.monnet@netronome.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-18-andriin@fb.com
| * selftests/bpf: Add test validating data section to struct convertion layoutAndrii Nakryiko2019-12-162-0/+88
| | | | | | | | | | | | | | | | | | | | | | Add a simple selftests validating datasection-to-struct layour dumping. Global variables are constructed in such a way as to cause both natural and artificial padding (through custom alignment requirement). Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-17-andriin@fb.com
| * selftests/bpf: Convert few more selftest to skeletonsAndrii Nakryiko2019-12-165-249/+149
| | | | | | | | | | | | | | | | | | | | Convert few more selftests to use generated BPF skeletons as a demonstration on how to use it. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-16-andriin@fb.com
| * selftests/bpf: Add BPF skeletons selftests and convert attach_probe.cAndrii Nakryiko2019-12-164-133/+74
| | | | | | | | | | | | | | | | | | | | Add BPF skeleton generation to selftest/bpf's Makefile. Convert attach_probe.c to use skeleton. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-15-andriin@fb.com
| * bpftool: Add skeleton codegen commandAndrii Nakryiko2019-12-163-1/+554
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add `bpftool gen skeleton` command, which takes in compiled BPF .o object file and dumps a BPF skeleton struct and related code to work with that skeleton. Skeleton itself is tailored to a specific structure of provided BPF object file, containing accessors (just plain struct fields) for every map and program, as well as dedicated space for bpf_links. If BPF program is using global variables, corresponding structure definitions of compatible memory layout are emitted as well, making it possible to initialize and subsequently read/update global variables values using simple and clear C syntax for accessing fields. This skeleton majorly improves usability of opening/loading/attaching of BPF object, as well as interacting with it throughout the lifetime of loaded BPF object. Generated skeleton struct has the following structure: struct <object-name> { /* used by libbpf's skeleton API */ struct bpf_object_skeleton *skeleton; /* bpf_object for libbpf APIs */ struct bpf_object *obj; struct { /* for every defined map in BPF object: */ struct bpf_map *<map-name>; } maps; struct { /* for every program in BPF object: */ struct bpf_program *<program-name>; } progs; struct { /* for every program in BPF object: */ struct bpf_link *<program-name>; } links; /* for every present global data section: */ struct <object-name>__<one of bss, data, or rodata> { /* memory layout of corresponding data section, * with every defined variable represented as a struct field * with exactly the same type, but without const/volatile * modifiers, e.g.: */ int *my_var_1; ... } *<one of bss, data, or rodata>; }; This provides great usability improvements: - no need to look up maps and programs by name, instead just my_obj->maps.my_map or my_obj->progs.my_prog would give necessary bpf_map/bpf_program pointers, which user can pass to existing libbpf APIs; - pre-defined places for bpf_links, which will be automatically populated for program types that libbpf knows how to attach automatically (currently tracepoints, kprobe/kretprobe, raw tracepoint and tracing programs). On tearing down skeleton, all active bpf_links will be destroyed (meaning BPF programs will be detached, if they are attached). For cases in which libbpf doesn't know how to auto-attach BPF program, user can manually create link after loading skeleton and they will be auto-detached on skeleton destruction: my_obj->links.my_fancy_prog = bpf_program__attach_cgroup_whatever( my_obj->progs.my_fancy_prog, <whatever extra param); - it's extremely easy and convenient to work with global data from userspace now. Both for read-only and read/write variables, it's possible to pre-initialize them before skeleton is loaded: skel = my_obj__open(raw_embed_data); my_obj->rodata->my_var = 123; my_obj__load(skel); /* 123 will be initialization value for my_var */ After load, if kernel supports mmap() for BPF arrays, user can still read (and write for .bss and .data) variables values, but at that point it will be directly mmap()-ed to BPF array, backing global variables. This allows to seamlessly exchange data with BPF side. From userspace program's POV, all the pointers and memory contents stay the same, but mapped kernel memory changes to point to created map. If kernel doesn't yet support mmap() for BPF arrays, it's still possible to use those data section structs to pre-initialize .bss, .data, and .rodata, but after load their pointers will be reset to NULL, allowing user code to gracefully handle this condition, if necessary. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-14-andriin@fb.com
| * libbpf: Add BPF object skeleton supportAndrii Nakryiko2019-12-163-0/+205
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add new set of APIs, allowing to open/load/attach BPF object through BPF object skeleton, generated by bpftool for a specific BPF object file. All the xxx_skeleton() APIs wrap up corresponding bpf_object_xxx() APIs, but additionally also automate map/program lookups by name, global data initialization and mmap()-ing, etc. All this greatly improves and simplifies userspace usability of working with BPF programs. See follow up patches for examples. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-13-andriin@fb.com
| * libbpf: Reduce log level of supported section names dumpAndrii Nakryiko2019-12-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | It's quite spammy. And now that bpf_object__open() is trying to determine program type from its section name, we are getting these verbose messages all the time. Reduce their log level to DEBUG. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-12-andriin@fb.com
| * libbpf: Postpone BTF ID finding for TRACING programs to load phaseAndrii Nakryiko2019-12-161-19/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move BTF ID determination for BPF_PROG_TYPE_TRACING programs to a load phase. Performing it at open step is inconvenient, because it prevents BPF skeleton generation on older host kernel, which doesn't contain BTF_KIND_FUNCs information in vmlinux BTF. This is a common set up, though, when, e.g., selftests are compiled on older host kernel, but the test program itself is executed in qemu VM with bleeding edge kernel. Having this BTF searching performed at load time allows to successfully use bpf_object__open() for codegen and inspection of BPF object file. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-11-andriin@fb.com
| * libbpf: Refactor global data map initializationAndrii Nakryiko2019-12-161-38/+59
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Refactor global data map initialization to use anonymous mmap()-ed memory instead of malloc()-ed one. This allows to do a transparent re-mmap()-ing of already existing memory address to point to BPF map's memory after bpf_object__load() step (done in follow up patch). This choreographed setup allows to have a nice and unsurprising way to pre-initialize read-only (and r/w as well) maps by user and after BPF map creation keep working with mmap()-ed contents of this map. All in a way that doesn't require user code to update any pointers: the illusion of working with memory contents is preserved before and after actual BPF map instantiation. Selftests and runqslower example demonstrate this feature in follow up patches. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-10-andriin@fb.com
| * libbpf: Expose BPF program's function nameAndrii Nakryiko2019-12-164-14/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add APIs to get BPF program function name, as opposed to bpf_program__title(), which returns BPF program function's section name. Function name has a benefit of being a valid C identifier and uniquely identifies a specific BPF program, while section name can be duplicated across multiple independent BPF programs. Add also bpf_object__find_program_by_name(), similar to bpf_object__find_program_by_title(), to facilitate looking up BPF programs by their C function names. Convert one of selftests to new API for look up. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-9-andriin@fb.com
| * libbpf: Expose BTF-to-C type declaration emitting APIAndrii Nakryiko2019-12-163-26/+65
| | | | | | | | | | | | | | | | | | | | | | | | | | Expose API that allows to emit type declaration and field/variable definition (if optional field name is specified) in valid C syntax for any provided BTF type. This is going to be used by bpftool when emitting data section layout as a struct. As part of making this API useful in a stand-alone fashion, move initialization of some of the internal btf_dump state to earlier phase. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191214014341.3442258-8-andriin@fb.com
| * libbpf: Expose btf__align_of() APIAndrii Nakryiko2019-12-164-41/+47
| | | | | | | | | | | | | | | | Expose BTF API that calculates type alignment requirements. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014341.3442258-7-andriin@fb.com
| * libbpf: Extract common user-facing helpersAndrii Nakryiko2019-12-164-34/+44
| | | | | | | | | | | | | | | | | | | | LIBBPF_API and DECLARE_LIBBPF_OPTS are needed in many public libbpf API headers. Extract them into libbpf_common.h to avoid unnecessary interdependency between btf.h, libbpf.h, and bpf.h or code duplication. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20191214014341.3442258-6-andriin@fb.com