kernel/linux.git/tools/bpf/bpftool/btf.c, branch v6.2.2

bpftool: clean-up usage of libbpf_get_error()

2022-11-21T00:17:46+00:00

bpftool is now totally compliant with libbpf 1.0 mode and is not expected to be compiled with pre-1.0, let's clean-up the usage of libbpf_get_error(). The changes stay aligned with returned errors always negative. - In tools/bpf/bpftool/btf.c This fixes an uninitialized local variable `err` in function do_dump() because it may now be returned without having been set. - This also removes the checks on NULL pointers before calling btf__free() because that function already does the check. Signed-off-by: Sahid Orentino Ferdjaoui Link: https://lore.kernel.org/r/20221120112515.38165-5-sahid.ferdjaoui@industrialdiscipline.com Signed-off-by: Alexei Starovoitov

libbpf: Hashmap interface update to allow both long and void* keys/values

2022-11-10T04:45:14+00:00

An update for libbpf's hashmap interface from void* -> void* to a polymorphic one, allowing both long and void* keys and values. This simplifies many use cases in libbpf as hashmaps there are mostly integer to integer. Perf copies hashmap implementation from libbpf and has to be updated as well. Changes to libbpf, selftests/bpf and perf are packed as a single commit to avoid compilation issues with any future bisect. Polymorphic interface is acheived by hiding hashmap interface functions behind auxiliary macros that take care of necessary type casts, for example: #define hashmap_cast_ptr(p) \ ({ \ _Static_assert((p) == NULL || sizeof(*(p)) == sizeof(long),\ #p " pointee should be a long-sized integer or a pointer"); \ (long *)(p); \ }) bool hashmap_find(const struct hashmap *map, long key, long *value); #define hashmap__find(map, key, value) \ hashmap_find((map), (long)(key), hashmap_cast_ptr(value)) - hashmap__find macro casts key and value parameters to long and long* respectively - hashmap_cast_ptr ensures that value pointer points to a memory of appropriate size. This hack was suggested by Andrii Nakryiko in [1]. This is a follow up for [2]. [1] https://lore.kernel.org/bpf/CAEf4BzZ8KFneEJxFAaNCCFPGqp20hSpS2aCj76uRk3-qZUH5xg@mail.gmail.com/ [2] https://lore.kernel.org/bpf/af1facf9-7bc8-8a3d-0db4-7b3f333589a2@meta.com/T/#m65b28f1d6d969fcd318b556db6a3ad499a42607d Signed-off-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221109142611.879983-2-eddyz87@gmail.com

bpftool: Fix error message of strerror

2022-09-30T22:40:46+00:00

strerror() expects a positive errno, however variable err will never be positive when an error occurs. This causes bpftool to output too many "unknown error", even a simple "file not exist" error can not get an accurate message. This patch fixed all "strerror(err)" patterns in bpftool. Specially in btf.c#L823, hashmap__append() is an internal function of libbpf and will not change errno, so there's a little difference. Some libbpf_get_error() calls are kept for return values. Changes since v1: https://lore.kernel.org/bpf/SY4P282MB1084B61CD8671DFA395AA8579D539@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM/ Check directly for NULL values instead of calling libbpf_get_error(). Signed-off-by: Tianyi Liu Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Link: https://lore.kernel.org/bpf/SY4P282MB1084AD9CD84A920F08DF83E29D549@SY4P282MB1084.AUSP282.PROD.OUTLOOK.COM

bpftool: Remove unused struct btf_attach_point

2022-09-30T21:08:40+00:00

After commit 2828d0d75b73 ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing"), struct btf_attach_point is not used anymore and can be removed as well. Signed-off-by: Yuan Can Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220928090440.79637-2-yuancan@huawei.com

bpftool: Add btf enum64 support

2022-06-07T17:20:43+00:00

Add BTF_KIND_ENUM64 support. For example, the following enum is defined in uapi bpf.h. $ cat core.c enum A { BPF_F_INDEX_MASK = 0xffffffffULL, BPF_F_CURRENT_CPU = BPF_F_INDEX_MASK, BPF_F_CTXLEN_MASK = (0xfffffULL << 32), } g; Compiled with clang -target bpf -O2 -g -c core.c Using bpftool to dump types and generate format C file: $ bpftool btf dump file core.o ... [1] ENUM64 'A' encoding=UNSIGNED size=8 vlen=3 'BPF_F_INDEX_MASK' val=4294967295ULL 'BPF_F_CURRENT_CPU' val=4294967295ULL 'BPF_F_CTXLEN_MASK' val=4503595332403200ULL $ bpftool btf dump file core.o format c ... enum A { BPF_F_INDEX_MASK = 4294967295ULL, BPF_F_CURRENT_CPU = 4294967295ULL, BPF_F_CTXLEN_MASK = 4503595332403200ULL, }; ... Note that for raw btf output, the encoding (UNSIGNED or SIGNED) is printed out as well. The 64bit value is also represented properly in BTF and C dump. Acked-by: Andrii Nakryiko Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20220607062652.3722649-1-yhs@fb.com Signed-off-by: Alexei Starovoitov

bpftool: Use sysfs vmlinux when dumping BTF by ID

2022-05-13T23:07:53+00:00

Currently, dumping almost all BTFs specified by id requires using the -B option to pass the base BTF. For kernel module BTFs the vmlinux BTF sysfs path should work. This patch simplifies dumping by ID usage by loading vmlinux BTF from sysfs as base, if base BTF was not specified and the ID corresponds to a kernel module BTF. Signed-off-by: Larysa Zaremba Signed-off-by: Andrii Nakryiko Reviewed-by: Alexander Lobakin Link: https://lore.kernel.org/bpf/20220513121743.12411-1-larysa.zaremba@intel.com

bpftool: Fix error check when calling hashmap__new()

2022-01-13T01:01:36+00:00

hashmap__new() encodes errors with ERR_PTR(), hence it's not valid to check the returned pointer against NULL and IS_ERR() has to be used instead. libbpf_get_error() can't be used in this case as hashmap__new() is not part of the public libbpf API and it'll continue using ERR_PTR() after libbpf 1.0. Fixes: 8f184732b60b ("bpftool: Switch to libbpf's hashmap for pinned paths of BPF objects") Fixes: 2828d0d75b73 ("bpftool: Switch to libbpf's hashmap for programs/maps in BTF listing") Fixes: d6699f8e0f83 ("bpftool: Switch to libbpf's hashmap for PIDs/names references") Signed-off-by: Mauricio Vásquez Signed-off-by: Andrii Nakryiko Reviewed-by: Quentin Monnet Acked-by: Song Liu Link: https://lore.kernel.org/bpf/20220107152620.192327-2-mauricio@kinvolk.io

bpftool: Use libbpf_get_error() to check error

2021-11-15T02:38:13+00:00

Currently, LIBBPF_STRICT_ALL mode is enabled by default for bpftool which means on error cases, some libbpf APIs would return NULL pointers. This makes IS_ERR check failed to detect such cases and result in segfault error. Use libbpf_get_error() instead like we do in libbpf itself. Signed-off-by: Hengqi Chen Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211115012436.3143318-1-hengqi.chen@gmail.com

bpftool: Support BTF_KIND_TYPE_TAG

2021-11-12T01:41:11+00:00

Add bpftool support for BTF_KIND_TYPE_TAG. Signed-off-by: Yonghong Song Signed-off-by: Alexei Starovoitov Acked-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20211112012620.1505506-1-yhs@fb.com

bpftool: Update btf_dump__new() and perf_buffer__new_raw() calls

2021-11-12T00:54:06+00:00

Use v1.0-compatible variants of btf_dump and perf_buffer "constructors". This is also a demonstration of reusing struct perf_buffer_raw_opts as OPTS-style option struct for new perf_buffer__new_raw() API. Signed-off-by: Andrii Nakryiko Signed-off-by: Alexei Starovoitov Link: https://lore.kernel.org/bpf/20211111053624.190580-10-andrii@kernel.org