kernel/linux.git/tools/lib/bpf/btf_dump.c, branch v6.2.6

libbpf: Fix single-line struct definition output in btf_dump

2023-03-10T08:28:02+00:00

[ Upstream commit 872aec4b5f635d94111d48ec3c57fbe078d64e7d ] btf_dump APIs emit unnecessary tabs when emitting struct/union definition that fits on the single line. Before this patch we'd get: struct blah {}; This patch fixes this and makes sure that we get more natural: struct blah {}; Fixes: 44a726c3f23c ("bpftool: Print newline before '}' for struct with padding only fields") Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20221212211505.558851-2-andrii@kernel.org Signed-off-by: Sasha Levin

libbpf: Ignore hashmap__find() result explicitly in btf_dump

2022-11-18T22:13:38+00:00

Coverity is reporting that btf_dump_name_dups() doesn't check return result of hashmap__find() call. This is intentional, so make it explicit with (void) cast. Signed-off-by: Andrii Nakryiko Signed-off-by: Daniel Borkmann Link: https://lore.kernel.org/bpf/20221117192824.4093553-1-andrii@kernel.org

libbpf: Fix uninitialized warning in btf_dump_dump_type_data

2022-11-14T18:02:32+00:00

GCC 11.3.0 fails to compile btf_dump.c due to the following error, which seems to originate in btf_dump_struct_data where the returned value would be uninitialized if btf_vlen returns zero. btf_dump.c: In function ‘btf_dump_dump_type_data’: btf_dump.c:2363:12: error: ‘err’ may be used uninitialized in this function [-Werror=maybe-uninitialized] 2363 | if (err < 0) | ^ Fixes: 920d16af9b42 ("libbpf: BTF dumper support for typed data") Signed-off-by: David Michael Signed-off-by: Daniel Borkmann Acked-by: Stanislav Fomichev Acked-by: Alan Maguire Link: https://lore.kernel.org/bpf/87zgcu60hq.fsf@gmail.com

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

libbpf: Fix use-after-free in btf_dump_name_dups

2022-10-13T17:53:03+00:00

ASAN reports an use-after-free in btf_dump_name_dups: ERROR: AddressSanitizer: heap-use-after-free on address 0xffff927006db at pc 0xaaaab5dfb618 bp 0xffffdd89b890 sp 0xffffdd89b928 READ of size 2 at 0xffff927006db thread T0 #0 0xaaaab5dfb614 in __interceptor_strcmp.part.0 (test_progs+0x21b614) #1 0xaaaab635f144 in str_equal_fn tools/lib/bpf/btf_dump.c:127 #2 0xaaaab635e3e0 in hashmap_find_entry tools/lib/bpf/hashmap.c:143 #3 0xaaaab635e72c in hashmap__find tools/lib/bpf/hashmap.c:212 #4 0xaaaab6362258 in btf_dump_name_dups tools/lib/bpf/btf_dump.c:1525 #5 0xaaaab636240c in btf_dump_resolve_name tools/lib/bpf/btf_dump.c:1552 #6 0xaaaab6362598 in btf_dump_type_name tools/lib/bpf/btf_dump.c:1567 #7 0xaaaab6360b48 in btf_dump_emit_struct_def tools/lib/bpf/btf_dump.c:912 #8 0xaaaab6360630 in btf_dump_emit_type tools/lib/bpf/btf_dump.c:798 #9 0xaaaab635f720 in btf_dump__dump_type tools/lib/bpf/btf_dump.c:282 #10 0xaaaab608523c in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:236 #11 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875 #12 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062 #13 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697 #14 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308 #15 0xaaaab5d65990 (test_progs+0x185990) 0xffff927006db is located 11 bytes inside of 16-byte region [0xffff927006d0,0xffff927006e0) freed by thread T0 here: #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4) #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191 #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163 #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106 #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157 #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519 #6 0xaaaab6353e10 in btf__add_field tools/lib/bpf/btf.c:2032 #7 0xaaaab6084fcc in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:232 #8 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875 #9 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062 #10 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697 #11 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308 #12 0xaaaab5d65990 (test_progs+0x185990) previously allocated by thread T0 here: #0 0xaaaab5e2c7c4 in realloc (test_progs+0x24c7c4) #1 0xaaaab634f4a0 in libbpf_reallocarray tools/lib/bpf/libbpf_internal.h:191 #2 0xaaaab634f840 in libbpf_add_mem tools/lib/bpf/btf.c:163 #3 0xaaaab636643c in strset_add_str_mem tools/lib/bpf/strset.c:106 #4 0xaaaab6366560 in strset__add_str tools/lib/bpf/strset.c:157 #5 0xaaaab6352d70 in btf__add_str tools/lib/bpf/btf.c:1519 #6 0xaaaab6353ff0 in btf_add_enum_common tools/lib/bpf/btf.c:2070 #7 0xaaaab6354080 in btf__add_enum tools/lib/bpf/btf.c:2102 #8 0xaaaab6082f50 in test_btf_dump_incremental tools/testing/selftests/bpf/prog_tests/btf_dump.c:162 #9 0xaaaab6097530 in test_btf_dump tools/testing/selftests/bpf/prog_tests/btf_dump.c:875 #10 0xaaaab6314ed0 in run_one_test tools/testing/selftests/bpf/test_progs.c:1062 #11 0xaaaab631a0a8 in main tools/testing/selftests/bpf/test_progs.c:1697 #12 0xffff9676d214 in __libc_start_main ../csu/libc-start.c:308 #13 0xaaaab5d65990 (test_progs+0x185990) The reason is that the key stored in hash table name_map is a string address, and the string memory is allocated by realloc() function, when the memory is resized by realloc() later, the old memory may be freed, so the address stored in name_map references to a freed memory, causing use-after-free. Fix it by storing duplicated string address in name_map. Fixes: 919d2b1dbb07 ("libbpf: Allow modification of BTF and add btf__add_str API") Signed-off-by: Xu Kuohai Signed-off-by: Andrii Nakryiko Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/20221011120108.782373-2-xukuohai@huaweicloud.com

bpftool: Print newline before '}' for struct with padding only fields

2022-10-05T22:27:08+00:00

btf_dump_emit_struct_def attempts to print empty structures at a single line, e.g. `struct empty {}`. However, it has to account for a case when there are no regular but some padding fields in the struct. In such case `vlen` would be zero, but size would be non-zero. E.g. here is struct bpf_timer from vmlinux.h before this patch: struct bpf_timer { long: 64; long: 64;}; And after this patch: struct bpf_dynptr { long: 64; long: 64; }; Signed-off-by: Eduard Zingerman Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20221001104425.415768-1-eddyz87@gmail.com

libbpf: Fix NULL pointer exception in API btf_dump__dump_type_data

2022-09-21T00:34:09+00:00

We found that function btf_dump__dump_type_data can be called by the user as an API, but in this function, the `opts` parameter may be used as a null pointer.This causes `opts->indent_str` to trigger a NULL pointer exception. Fixes: 2ce8450ef5a3 ("libbpf: add bpf_object__open_{file, mem} w/ extensible opts") Signed-off-by: Xin Liu Signed-off-by: Weibin Kong Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220917084809.30770-1-liuxin350@huawei.com

libbpf: Fix sign expansion bug in btf_dump_get_enum_value()

2022-07-21T12:24:18+00:00

The code here is supposed to take a signed int and store it in a signed long long. Unfortunately, the way that the type promotion works with this conditional statement is that it takes a signed int, type promotes it to a __u32, and then stores that as a signed long long. The result is never negative. This is from static analysis, but I made a little test program just to test it before I sent the patch: #include int main(void) { unsigned long long src = -1ULL; signed long long dst1, dst2; int is_signed = 1; dst1 = is_signed ? *(int *)&src : *(unsigned int *)0; dst2 = is_signed ? (signed long long)*(int *)&src : *(unsigned int *)0; printf("%lld\n", dst1); printf("%lld\n", dst2); return 0; } Fixes: d90ec262b35b ("libbpf: Add enum64 support for btf_dump") Signed-off-by: Dan Carpenter Signed-off-by: Daniel Borkmann Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/YtZ+LpgPADm7BeEd@kili

libbpf: remove deprecated BTF APIs

2022-06-28T20:13:32+00:00

Get rid of deprecated BTF-related APIs. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20220627211527.2245459-6-andrii@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Add enum64 support for btf_dump

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

Add enum64 btf dumping support. For long long and unsigned long long dump, suffixes 'LL' and 'ULL' are added to avoid compilation errors in some cases. Acked-by: Andrii Nakryiko Signed-off-by: Yonghong Song Link: https://lore.kernel.org/r/20220607062631.3720526-1-yhs@fb.com Signed-off-by: Alexei Starovoitov