kernel/linux.git/tools/lib/bpf/libbpf_internal.h, branch v6.19.11

libbpf: support llvm-generated indirect jumps

2025-11-06T01:53:23+00:00

For v4 instruction set LLVM is allowed to generate indirect jumps for switch statements and for 'goto *rX' assembly. Every such a jump will be accompanied by necessary metadata, e.g. (`llvm-objdump -Sr ...`): 0: r2 = 0x0 ll 0000000000000030: R_BPF_64_64 BPF.JT.0.0 Here BPF.JT.1.0 is a symbol residing in the .jumptables section: Symbol table: 4: 0000000000000000 240 OBJECT GLOBAL DEFAULT 4 BPF.JT.0.0 The -bpf-min-jump-table-entries llvm option may be used to control the minimal size of a switch which will be converted to an indirect jumps. Signed-off-by: Anton Protopopov Acked-by: Eduard Zingerman Link: https://lore.kernel.org/r/20251105090410.1250500-11-a.s.protopopov@gmail.com Signed-off-by: Alexei Starovoitov

libbpf: move libbpf_sha256() implementation into libbpf_utils.c

2025-10-01T22:27:25+00:00

Move sha256 implementation out of already large and unwieldy libbpf.c into libbpf_utils.c where we'll keep reusable helpers. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20251001171326.3883055-5-andrii@kernel.org Signed-off-by: Alexei Starovoitov Acked-by: Eduard Zingerman

libbpf: move libbpf_errstr() into libbpf_utils.c

2025-10-01T22:27:25+00:00

Get rid of str_err.{c,h} by moving implementation of libbpf_errstr() into libbpf_utils.c and declarations into libbpf_internal.h. Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/r/20251001171326.3883055-4-andrii@kernel.org Signed-off-by: Alexei Starovoitov Acked-by: Eduard Zingerman

libbpf: Replace AF_ALG with open coded SHA-256

2025-09-28T11:25:31+00:00

Reimplement libbpf_sha256() using some basic SHA-256 C code. This eliminates the newly-added dependency on AF_ALG, which is a problematic UAPI that is not supported by all kernels. Make libbpf_sha256() return void, since it can no longer fail. This simplifies some callers. Also drop the unnecessary 'sha_out_sz' parameter. Finally, also fix the typo in "compute_sha_udpate_offsets". Fixes: c297fe3e9f99 ("libbpf: Implement SHA256 internal helper") Signed-off-by: Eric Biggers Link: https://lore.kernel.org/r/20250928003833.138407-1-ebiggers@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Implement SHA256 internal helper

2025-09-19T02:11:42+00:00

Use AF_ALG sockets to not have libbpf depend on OpenSSL. The helper is used for the loader generation code to embed the metadata hash in the loader program and also by the bpf_map__make_exclusive API to calculate the hash of the program the map is exclusive to. Acked-by: Andrii Nakryiko Signed-off-by: KP Singh Link: https://lore.kernel.org/r/20250914215141.15144-4-kpsingh@kernel.org Signed-off-by: Alexei Starovoitov

libbpf: Fix implicit memfd_create() for bionic

2025-04-04T15:52:37+00:00

Since memfd_create() is not consistently available across different bionic libc implementations, using memfd_create() directly can break some Android builds: tools/lib/bpf/linker.c:576:7: error: implicit declaration of function 'memfd_create' [-Werror,-Wimplicit-function-declaration] 576 | fd = memfd_create(filename, 0); | ^ To fix this, relocate and inline the sys_memfd_create() helper so that it can be used in "linker.c". Similar issues were previously fixed by commit 9fa5e1a180aa ("libbpf: Call memfd_create() syscall directly"). Fixes: 6d5e5e5d7ce1 ("libbpf: Extend linker API to support in-memory ELF files") Signed-off-by: Carlos Llamas Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20250330211325.530677-1-cmllamas@google.com

libbpf: Pass BPF token from find_prog_btf_id to BPF_BTF_GET_FD_BY_ID

2025-03-17T20:45:12+00:00

Pass BPF token from bpf_program__set_attach_target to BPF_BTF_GET_FD_BY_ID bpf command. When freplace program attaches to target program, it needs to look up for BTF of the target, this may require BPF token, if, for example, running from user namespace. Signed-off-by: Mykyta Yatsenko Signed-off-by: Andrii Nakryiko Acked-by: Yonghong Song Link: https://lore.kernel.org/bpf/20250317174039.161275-4-mykyta.yatsenko5@gmail.com

libbpf: Support opening bpf objects of either endianness

2024-10-04T00:47:36+00:00

Allow bpf_object__open() to access files of either endianness, and convert included BPF programs to native byte-order in-memory for introspection. Loading BPF objects of non-native byte-order is still disallowed however. Signed-off-by: Tony Ambardar Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/26353c1a1887a54400e1acd6c138fa90c99cdd40.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov

libbpf: Support BTF.ext loading and output in either endianness

2024-10-04T00:47:36+00:00

Support for handling BTF data of either endianness was added in [1], but did not include BTF.ext data for lack of use cases. Later, support for static linking [2] provided a use case, but this feature and later ones were restricted to native-endian usage. Add support for BTF.ext handling in either endianness. Convert BTF.ext data to native endianness when read into memory for further processing, and support raw data access that restores the original byte-order for output. Add internal header functions for byte-swapping func, line, and core info records. Add new API functions btf_ext__endianness() and btf_ext__set_endianness() for query and setting byte-order, as already exist for BTF data. [1] 3289959b97ca ("libbpf: Support BTF loading and raw data output in both endianness") [2] 8fd27bf69b86 ("libbpf: Add BPF static linker BTF and BTF.ext support") Signed-off-by: Tony Ambardar Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/133407ab20e0dd5c07cab2a6fa7879dee1ffa4bc.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov

libbpf: Fix header comment typos for BTF.ext

2024-10-04T00:47:36+00:00

Mention struct btf_ext_info_sec rather than non-existent btf_sec_func_info in BTF.ext struct documentation. Signed-off-by: Tony Ambardar Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/cde65e01a5f2945c578485fab265ef711e2daeb6.1726475448.git.tony.ambardar@gmail.com Signed-off-by: Alexei Starovoitov