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2020-02-07bpftool: Don't crash on missing xlated program instructionsToke Høiland-Jørgensen
Turns out the xlated program instructions can also be missing if kptr_restrict sysctl is set. This means that the previous fix to check the jited_prog_insns pointer was insufficient; add another check of the xlated_prog_insns pointer as well. Fixes: 5b79bcdf0362 ("bpftool: Don't crash on missing jited insns or ksyms") Fixes: cae73f233923 ("bpftool: use bpf_program__get_prog_info_linear() in prog.c:do_dump()") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin@isovalent.com> Link: https://lore.kernel.org/bpf/20200206102906.112551-1-toke@redhat.com
2020-02-04bpftool: Remove redundant "HAVE" prefix from the large INSN limit checkMichal Rostecki
"HAVE" prefix is already applied by default to feature macros and before this change, the large INSN limit macro had the incorrect name with double "HAVE". Fixes: 2faef64aa6b3 ("bpftool: Add misc section and probe for large INSN limit") Signed-off-by: Michal Rostecki <mrostecki@opensuse.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Link: https://lore.kernel.org/bpf/20200202110200.31024-1-mrostecki@opensuse.org
2020-01-24bpftool: Print function linkage in BTF dumpAndrii Nakryiko
Add printing out BTF_KIND_FUNC's linkage. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20200124054317.2459436-1-andriin@fb.com
2020-01-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Alexei Starovoitov says: ==================== pull-request: bpf-next 2020-01-22 The following pull-request contains BPF updates for your *net-next* tree. We've added 92 non-merge commits during the last 16 day(s) which contain a total of 320 files changed, 7532 insertions(+), 1448 deletions(-). The main changes are: 1) function by function verification and program extensions from Alexei. 2) massive cleanup of selftests/bpf from Toke and Andrii. 3) batched bpf map operations from Brian and Yonghong. 4) tcp congestion control in bpf from Martin. 5) bulking for non-map xdp_redirect form Toke. 6) bpf_send_signal_thread helper from Yonghong. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-01-20bpftool: Use consistent include paths for libbpfToke Høiland-Jørgensen
Fix bpftool to include libbpf header files with the bpf/ prefix, to be consistent with external users of the library. Also ensure that all includes of exported libbpf header files (those that are exported on 'make install' of the library) use bracketed includes instead of quoted. To make sure no new files are introduced that doesn't include the bpf/ prefix in its include, remove tools/lib/bpf from the include path entirely, and use tools/lib instead. Fixes: 6910d7d3867a ("selftests/bpf: Ensure bpf_helper_defs.h are taken from selftests dir") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/157952560684.1683545.4765181397974997027.stgit@toke.dk
2020-01-19Merge ra.kernel.org:/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
2020-01-15bpftool: Support dumping a map with btf_vmlinux_value_type_idMartin KaFai Lau
This patch makes bpftool support dumping a map's value properly when the map's value type is a type of the running kernel's btf. (i.e. map_info.btf_vmlinux_value_type_id is set instead of map_info.btf_value_type_id). The first usecase is for the BPF_MAP_TYPE_STRUCT_OPS. Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200115230044.1103008-1-kafai@fb.com
2020-01-15bpftool: Add struct_ops map nameMartin KaFai Lau
This patch adds BPF_MAP_TYPE_STRUCT_OPS to "struct_ops" name mapping so that "bpftool map show" can print the "struct_ops" map type properly. [root@arch-fb-vm1 bpf]# ~/devshare/fb-kernel/linux/tools/bpf/bpftool/bpftool map show id 8 8: struct_ops name dctcp flags 0x0 key 4B value 256B max_entries 1 memlock 4096B btf_id 7 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200115230037.1102674-1-kafai@fb.com
2020-01-15bpftool: Fix missing BTF output for json during map dumpMartin KaFai Lau
The btf availability check is only done for plain text output. It causes the whole BTF output went missing when json_output is used. This patch simplifies the logic a little by avoiding passing "int btf" to map_dump(). For plain text output, the btf_wtr is only created when the map has BTF (i.e. info->btf_id != 0). The nullness of "json_writer_t *wtr" in map_dump() alone can decide if dumping BTF output is needed. As long as wtr is not NULL, map_dump() will print out the BTF-described data whenever a map has BTF available (i.e. info->btf_id != 0) regardless of json or plain-text output. In do_dump(), the "int btf" is also renamed to "int do_plain_btf". Fixes: 99f9863a0c45 ("bpftool: Match maps by name") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Cc: Paul Chaignon <paul.chaignon@orange.com> Link: https://lore.kernel.org/bpf/20200115230025.1101828-1-kafai@fb.com
2020-01-15bpftool: Fix a leak of btf objectMartin KaFai Lau
When testing a map has btf or not, maps_have_btf() tests it by actually getting a btf_fd from sys_bpf(BPF_BTF_GET_FD_BY_ID). However, it forgot to btf__free() it. In maps_have_btf() stage, there is no need to test it by really calling sys_bpf(BPF_BTF_GET_FD_BY_ID). Testing non zero info.btf_id is good enough. Also, the err_close case is unnecessary, and also causes double close() because the calling func do_dump() will close() all fds again. Fixes: 99f9863a0c45 ("bpftool: Match maps by name") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Cc: Paul Chaignon <paul.chaignon@orange.com> Link: https://lore.kernel.org/bpf/20200115230019.1101352-1-kafai@fb.com
2020-01-13bpftool: Apply preserve_access_index attribute to all types in BTF dumpAndrii Nakryiko
This patch makes structs and unions, emitted through BTF dump, automatically CO-RE-relocatable (unless disabled with `#define BPF_NO_PRESERVE_ACCESS_INDEX`, specified before including generated header file). This effectivaly turns usual bpf_probe_read() call into equivalent of bpf_core_read(), by automatically applying builtin_preserve_access_index to any field accesses of types in generated C types header. This is especially useful for tp_btf/fentry/fexit BPF program types. They allow direct memory access, so BPF C code just uses straightfoward a->b->c access pattern to read data from kernel. But without kernel structs marked as CO-RE relocatable through preserve_access_index attribute, one has to enclose all the data reads into a special __builtin_preserve_access_index code block, like so: __builtin_preserve_access_index(({ x = p->pid; /* where p is struct task_struct *, for example */ })); This is very inconvenient and obscures the logic quite a bit. By marking all auto-generated types with preserve_access_index attribute the above code is reduced to just a clean and natural `x = p->pid;`. Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200113073143.1779940-5-andriin@fb.com
2020-01-11bpftool: Fix printing incorrect pointer in btf_dump_ptrMartin KaFai Lau
For plain text output, it incorrectly prints the pointer value "void *data". The "void *data" is actually pointing to memory that contains a bpf-map's value. The intention is to print the content of the bpf-map's value instead of printing the pointer pointing to the bpf-map's value. In this case, a member of the bpf-map's value is a pointer type. Thus, it should print the "*(void **)data". Fixes: 22c349e8db89 ("tools: bpftool: fix format strings and arguments for jsonw_printf()") Signed-off-by: Martin KaFai Lau <kafai@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Link: https://lore.kernel.org/bpf/20200110231644.3484151-1-kafai@fb.com
2020-01-08bpftool: Add misc section and probe for large INSN limitMichal Rostecki
Introduce a new probe section (misc) for probes not related to concrete map types, program types, functions or kernel configuration. Introduce a probe for large INSN limit as the first one in that section. Example outputs: # bpftool feature probe [...] Scanning miscellaneous eBPF features... Large program size limit is available # bpftool feature probe macros [...] /*** eBPF misc features ***/ #define HAVE_HAVE_LARGE_INSN_LIMIT # bpftool feature probe -j | jq '.["misc"]' { "have_large_insn_limit": true } Signed-off-by: Michal Rostecki <mrostecki@opensuse.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Link: https://lore.kernel.org/bpf/20200108162428.25014-3-mrostecki@opensuse.org
2019-12-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
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>
2019-12-27bpftool: Make skeleton C code compilable with C++ compilerAndrii Nakryiko
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
2019-12-26bpf: Print error message for bpftool cgroup showHechao Li
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
2019-12-18libbpf: Put Kconfig externs into .kconfig sectionAndrii Nakryiko
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
2019-12-18bpftool: Work-around rst2man conversion bugAndrii Nakryiko
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
2019-12-18bpftool: Simplify format string to not use positional argsAndrii Nakryiko
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
2019-12-17bpftool: Add gen subcommand manpageAndrii Nakryiko
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
2019-12-17bpftool, selftests/bpf: Embed object file inside skeletonAndrii Nakryiko
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
2019-12-16bpftool: Fix compilation warning on shadowed variablePaul Chaignon
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
2019-12-15bpftool: Generate externs datasec in BPF skeletonAndrii Nakryiko
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
2019-12-15bpftool: Add `gen skeleton` BASH completionsAndrii Nakryiko
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
2019-12-15bpftool: Add skeleton codegen commandAndrii Nakryiko
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
2019-12-15libbpf: Move non-public APIs from libbpf.h to libbpf_internal.hAndrii Nakryiko
Few libbpf APIs are not public but currently exposed through libbpf.h to be used by bpftool. Move them to libbpf_internal.h, where intent of being non-stable and non-public is much more obvious. 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/20191214014341.3442258-4-andriin@fb.com
2019-12-15bpftool: Match maps by namePaul Chaignon
This patch implements lookup by name for maps and changes the behavior of lookups by tag to be consistent with prog subcommands. Similarly to program subcommands, the show and dump commands will return all maps with the given name (or tag), whereas other commands will error out if several maps have the same name (resp. tag). When a map has BTF info, it is dumped in JSON with available BTF info. This patch requires that all matched maps have BTF info before switching the output format to JSON. Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/8de1c9f273860b3ea1680502928f4da2336b853e.1576263640.git.paul.chaignon@gmail.com
2019-12-15bpftool: Match programs by namePaul Chaignon
When working with frequently modified BPF programs, both the ID and the tag may change. bpftool currently doesn't provide a "stable" way to match such programs. This patch implements lookup by name for programs. The show and dump commands will return all programs with the given name, whereas other commands will error out if several programs have the same name. Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Quentin Monnet <quentin.monnet@netronome.com> Link: https://lore.kernel.org/bpf/b5fc1a5dcfaeb5f16fc80295cdaa606dd2d91534.1576263640.git.paul.chaignon@gmail.com
2019-12-15bpftool: Match several programs with same tagPaul Chaignon
When several BPF programs have the same tag, bpftool matches only the first (in ID order). This patch changes that behavior such that dump and show commands return all matched programs. Commands that require a single program (e.g., pin and attach) will error out if given a tag that matches several. bpftool prog dump will also error out if file or visual are given and several programs have the given tag. In the case of the dump command, a program header is added before each dump only if the tag matches several programs; this patch doesn't change the output if a single program matches. The output when several programs match thus looks as follows. $ ./bpftool prog dump xlated tag 6deef7357e7b4530 3: cgroup_skb tag 6deef7357e7b4530 gpl 0: (bf) r6 = r1 [...] 7: (95) exit 4: cgroup_skb tag 6deef7357e7b4530 gpl 0: (bf) r6 = r1 [...] 7: (95) exit Signed-off-by: Paul Chaignon <paul.chaignon@orange.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/fb1fe943202659a69cd21dd5b907c205af1e1e22.1576263640.git.paul.chaignon@gmail.com
2019-12-11bpftool: Don't crash on missing jited insns or ksymsToke Høiland-Jørgensen
When the kptr_restrict sysctl is set, the kernel can fail to return jited_ksyms or jited_prog_insns, but still have positive values in nr_jited_ksyms and jited_prog_len. This causes bpftool to crash when trying to dump the program because it only checks the len fields not the actual pointers to the instructions and ksyms. Fix this by adding the missing checks. Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Fixes: f84192ee00b7 ("tools: bpftool: resolve calls without using imm field") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Martin KaFai Lau <kafai@fb.com> Link: https://lore.kernel.org/bpf/20191210181412.151226-1-toke@redhat.com
2019-11-24tools, bpftool: Fix warning on ignored return value for 'read'Quentin Monnet
When building bpftool, a warning was introduced by commit a94364603610 ("bpftool: Allow to read btf as raw data"), because the return value from a call to 'read()' is ignored. Let's address it. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20191119111706.22440-1-quentin.monnet@netronome.com
2019-10-25bpftool: Allow to read btf as raw dataJiri Olsa
The bpftool interface stays the same, but now it's possible to run it over BTF raw data, like: $ bpftool btf dump file /sys/kernel/btf/vmlinux [1] INT '(anon)' size=4 bits_offset=0 nr_bits=32 encoding=(none) [2] INT 'long unsigned int' size=8 bits_offset=0 nr_bits=64 encoding=(none) [3] CONST '(anon)' type_id=2 Signed-off-by: Jiri Olsa <jolsa@kernel.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Andrii Nakryiko <andriin@fb.com> Acked-by: Jakub Kicinski <jakub.kicinski@netronome.com> Link: https://lore.kernel.org/bpf/20191024133025.10691-1-jolsa@kernel.org
2019-10-22libbpf: Make DECLARE_LIBBPF_OPTS macro strictly a variable declarationAndrii Nakryiko
LIBBPF_OPTS is implemented as a mix of field declaration and memset + assignment. This makes it neither variable declaration nor purely statements, which is a problem, because you can't mix it with either other variable declarations nor other function statements, because C90 compiler mode emits warning on mixing all that together. This patch changes LIBBPF_OPTS into a strictly declaration of variable and solves this problem, as can be seen in case of bpftool, which previously would emit compiler warning, if done this way (LIBBPF_OPTS as part of function variables declaration block). This patch also renames LIBBPF_OPTS into DECLARE_LIBBPF_OPTS to follow kernel convention for similar macros more closely. v1->v2: - rename LIBBPF_OPTS into DECLARE_LIBBPF_OPTS (Jakub Sitnicki). Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/bpf/20191022172100.3281465-1-andriin@fb.com
2019-10-07bpftool: Fix bpftool build by switching to bpf_object__open_file()Andrii Nakryiko
As part of libbpf in 5e61f2707029 ("libbpf: stop enforcing kern_version, populate it for users") non-LIBBPF_API __bpf_object__open_xattr() API was removed from libbpf.h header. This broke bpftool, which relied on that function. This patch fixes the build by switching to newly added bpf_object__open_file() which provides the same capabilities, but is official and future-proof API. v1->v2: - fix prog_type shadowing (Stanislav). Fixes: 5e61f2707029 ("libbpf: stop enforcing kern_version, populate it for users") Reported-by: Stanislav Fomichev <sdf@google.com> Signed-off-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Reviewed-by: Stanislav Fomichev <sdf@google.com> Link: https://lore.kernel.org/bpf/20191007225604.2006146-1-andriin@fb.com
2019-09-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-nextDavid S. Miller
Daniel Borkmann says: ==================== The following pull-request contains BPF updates for your *net-next* tree. The main changes are: 1) Add the ability to use unaligned chunks in the AF_XDP umem. By relaxing where the chunks can be placed, it allows to use an arbitrary buffer size and place whenever there is a free address in the umem. Helps more seamless DPDK AF_XDP driver integration. Support for i40e, ixgbe and mlx5e, from Kevin and Maxim. 2) Addition of a wakeup flag for AF_XDP tx and fill rings so the application can wake up the kernel for rx/tx processing which avoids busy-spinning of the latter, useful when app and driver is located on the same core. Support for i40e, ixgbe and mlx5e, from Magnus and Maxim. 3) bpftool fixes for printf()-like functions so compiler can actually enforce checks, bpftool build system improvements for custom output directories, and addition of 'bpftool map freeze' command, from Quentin. 4) Support attaching/detaching XDP programs from 'bpftool net' command, from Daniel. 5) Automatic xskmap cleanup when AF_XDP socket is released, and several barrier/{read,write}_once fixes in AF_XDP code, from Björn. 6) Relicense of bpf_helpers.h/bpf_endian.h for future libbpf inclusion as well as libbpf versioning improvements, from Andrii. 7) Several new BPF kselftests for verifier precision tracking, from Alexei. 8) Several BPF kselftest fixes wrt endianess to run on s390x, from Ilya. 9) And more BPF kselftest improvements all over the place, from Stanislav. 10) Add simple BPF map op cache for nfp driver to batch dumps, from Jakub. 11) AF_XDP socket umem mapping improvements for 32bit archs, from Ivan. 12) Add BPF-to-BPF call and BTF line info support for s390x JIT, from Yauheni. 13) Small optimization in arm64 JIT to spare 1 insns for BPF_MOD, from Jerin. 14) Fix an error check in bpf_tcp_gen_syncookie() helper, from Petar. 15) Various minor fixes and cleanups, from Nathan, Masahiro, Masanari, Peter, Wei, Yue. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-31tools: bpftool: do not link twice against libbpf.a in MakefileQuentin Monnet
In bpftool's Makefile, $(LIBS) includes $(LIBBPF), therefore the library is used twice in the linking command. No need to have $(LIBBPF) (from $^) on that command, let's do with "$(OBJS) $(LIBS)" (but move $(LIBBPF) _before_ the -l flags in $(LIBS)). Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31tools: bpf: account for generated feature/ and libbpf/ directoriesQuentin Monnet
When building "tools/bpf" from the top of the Linux repository, the build system passes a value for the $(OUTPUT) Makefile variable to tools/bpf/Makefile and tools/bpf/bpftool/Makefile, which results in generating "libbpf/" (for bpftool) and "feature/" (bpf and bpftool) directories inside the tree. This commit adds such directories to the relevant .gitignore files, and edits the Makefiles to ensure they are removed on "make clean". The use of "rm" is also made consistent throughout those Makefiles (relies on the $(RM) variable, use "--" to prevent interpreting $(OUTPUT)/$(DESTDIR) as options. v2: - New patch. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31tools: bpftool: improve and check builds for different make invocationsQuentin Monnet
There are a number of alternative "make" invocations that can be used to compile bpftool. The following invocations are expected to work: - through the kbuild system, from the top of the repository (make tools/bpf) - by telling make to change to the bpftool directory (make -C tools/bpf/bpftool) - by building the BPF tools from tools/ (cd tools && make bpf) - by running make from bpftool directory (cd tools/bpf/bpftool && make) Additionally, setting the O or OUTPUT variables should tell the build system to use a custom output path, for each of these alternatives. The following patch fixes the following invocations: $ make tools/bpf $ make tools/bpf O=<dir> $ make -C tools/bpf/bpftool OUTPUT=<dir> $ make -C tools/bpf/bpftool O=<dir> $ cd tools/ && make bpf O=<dir> $ cd tools/bpf/bpftool && make OUTPUT=<dir> $ cd tools/bpf/bpftool && make O=<dir> After this commit, the build still fails for two variants when passing the OUTPUT variable: $ make tools/bpf OUTPUT=<dir> $ cd tools/ && make bpf OUTPUT=<dir> In order to remember and check what make invocations are supposed to work, and to document the ones which do not, a new script is added to the BPF selftests. Note that some invocations require the kernel to be configured, so the script skips them if no .config file is found. v2: - In make_and_clean(), set $ERROR to 1 when "make" returns non-zero, even if the binary was produced. - Run "make clean" from the correct directory (bpf/ instead of bpftool/, when relevant). Reported-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-31tools: bpftool: ignore make built-in rules for getting kernel versionQuentin Monnet
Bpftool calls the toplevel Makefile to get the kernel version for the sources it is built from. But when the utility is built from the top of the kernel repository, it may dump the following error message for certain architectures (including x86): $ make tools/bpf [...] make[3]: *** [checkbin] Error 1 [...] This does not prevent bpftool compilation, but may feel disconcerting. The "checkbin" arch-dependent target is not supposed to be called for target "kernelversion", which is a simple "echo" of the version number. It turns out this is caused by the make invocation in tools/bpf/bpftool, which attempts to find implicit rules to apply. Extract from debug output: Reading makefiles... Reading makefile 'Makefile'... Reading makefile 'scripts/Kbuild.include' (search path) (no ~ expansion)... Reading makefile 'scripts/subarch.include' (search path) (no ~ expansion)... Reading makefile 'arch/x86/Makefile' (search path) (no ~ expansion)... Reading makefile 'scripts/Makefile.kcov' (search path) (no ~ expansion)... Reading makefile 'scripts/Makefile.gcc-plugins' (search path) (no ~ expansion)... Reading makefile 'scripts/Makefile.kasan' (search path) (no ~ expansion)... Reading makefile 'scripts/Makefile.extrawarn' (search path) (no ~ expansion)... Reading makefile 'scripts/Makefile.ubsan' (search path) (no ~ expansion)... Updating makefiles.... Considering target file 'scripts/Makefile.ubsan'. Looking for an implicit rule for 'scripts/Makefile.ubsan'. Trying pattern rule with stem 'Makefile.ubsan'. [...] Trying pattern rule with stem 'Makefile.ubsan'. Trying implicit prerequisite 'scripts/Makefile.ubsan.o'. Looking for a rule with intermediate file 'scripts/Makefile.ubsan.o'. Avoiding implicit rule recursion. Trying pattern rule with stem 'Makefile.ubsan'. Trying rule prerequisite 'prepare'. Trying rule prerequisite 'FORCE'. Found an implicit rule for 'scripts/Makefile.ubsan'. Considering target file 'prepare'. File 'prepare' does not exist. Considering target file 'prepare0'. File 'prepare0' does not exist. Considering target file 'archprepare'. File 'archprepare' does not exist. Considering target file 'archheaders'. File 'archheaders' does not exist. Finished prerequisites of target file 'archheaders'. Must remake target 'archheaders'. Putting child 0x55976f4f6980 (archheaders) PID 31743 on the chain. To avoid that, pass the -r and -R flags to eliminate the use of make built-in rules (and while at it, built-in variables) when running command "make kernelversion" from bpftool's Makefile. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Minor conflict in r8169, bug fix had two versions in net and net-next, take the net-next hunks. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-21tools: bpftool: add "bpftool map freeze" subcommandQuentin Monnet
Add a new subcommand to freeze maps from user space. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-21tools: bpftool: show frozen status for mapsQuentin Monnet
When listing maps, read their "frozen" status from procfs, and tell if maps are frozen. As commit log for map freezing command mentions that the feature might be extended with flags (e.g. for write-only instead of read-only) in the future, use an integer and not a boolean for JSON output. Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
2019-08-20tools: bpftool: implement "bpftool btf show|list"Quentin Monnet
Add a "btf list" (alias: "btf show") subcommand to bpftool in order to dump all BTF objects loaded on a system. When running the command, hash tables are built in bpftool to retrieve all the associations between BTF objects and BPF maps and programs. This allows for printing all such associations when listing the BTF objects. The command is added at the top of the subcommands for "bpftool btf", so that typing only "bpftool btf" also comes down to listing the programs. We could not have this with the previous command ("dump"), which required a BTF object id, so it should not break any previous behaviour. This also makes the "btf" command behaviour consistent with "prog" or "map". Bash completion is updated to use "bpftool btf" instead of "bpftool prog" to list the BTF ids, as it looks more consistent. Example output (plain): # bpftool btf show 9: size 2989B prog_ids 21 map_ids 15 17: size 2847B prog_ids 36 map_ids 30,29,28 26: size 2847B Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-19Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
Merge conflict of mlx5 resolved using instructions in merge commit 9566e650bf7fdf58384bb06df634f7531ca3a97e. Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-15tools: bpftool: close prog FD before exit on showing a single programQuentin Monnet
When showing metadata about a single program by invoking "bpftool prog show PROG", the file descriptor referring to the program is not closed before returning from the function. Let's close it. Fixes: 71bb428fe2c1 ("tools: bpf: add bpftool") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Andrii Nakryiko <andriin@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15tools: bpftool: move "__printf()" attributes to header fileQuentin Monnet
Some functions in bpftool have a "__printf()" format attributes to tell the compiler they should expect printf()-like arguments. But because these attributes are not used for the function prototypes in the header files, the compiler does not run the checks everywhere the functions are used, and some mistakes on format string and corresponding arguments slipped in over time. Let's move the __printf() attributes to the correct places. Note: We add guards around the definition of GCC_VERSION in tools/include/linux/compiler-gcc.h to prevent a conflict in jit_disasm.c on GCC_VERSION from headers pulled via libbfd. Fixes: c101189bc968 ("tools: bpftool: fix -Wmissing declaration warnings") Reported-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15tools: bpftool: fix format string for p_err() in detect_common_prefix()Quentin Monnet
There is one call to the p_err() function in detect_common_prefix() where the message to print is passed directly as the first argument, without using a format string. This is harmless, but may trigger warnings if the "__printf()" attribute is used correctly for the p_err() function. Let's fix it by using a "%s" format string. Fixes: ba95c7452439 ("tools: bpftool: add "prog run" subcommand to test-run programs") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15tools: bpftool: fix format string for p_err() in query_flow_dissector()Quentin Monnet
The format string passed to one call to the p_err() function in query_flow_dissector() does not match the value that should be printed, resulting in some garbage integer being printed instead of strerror(errno) if /proc/self/ns/net cannot be open. Let's fix the format string. Fixes: 7f0c57fec80f ("bpftool: show flow_dissector attachment status") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15tools: bpftool: fix argument for p_err() in BTF do_dump()Quentin Monnet
The last argument passed to one call to the p_err() function is not correct, it should be "*argv" instead of "**argv". This may lead to a segmentation fault error if BTF id cannot be parsed correctly. Let's fix this. Fixes: c93cc69004dt ("bpftool: add ability to dump BTF types") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2019-08-15tools: bpftool: fix format strings and arguments for jsonw_printf()Quentin Monnet
There are some mismatches between format strings and arguments passed to jsonw_printf() in the BTF dumper for bpftool, which seems harmless but may result in warnings if the "__printf()" attribute is used correctly for jsonw_printf(). Let's fix relevant format strings and type cast. Fixes: b12d6ec09730 ("bpf: btf: add btf print functionality") Signed-off-by: Quentin Monnet <quentin.monnet@netronome.com> Reviewed-by: Jakub Kicinski <jakub.kicinski@netronome.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org>