kernel/tools/lib/bpf/bpf_tracing.h, branch linux-rolling-stable

libbpf: Fix powerpc's stack register definition in bpf_tracing.h

2025-11-13T20:36:40Z

[ Upstream commit 7221b9caf84b3294688228a19273d74ea19a2ee4 ] retsnoop's build on powerpc (ppc64le) architecture ([0]) failed due to wrong definition of PT_REGS_SP() macro. Looking at powerpc's implementation of stack unwinding in perf_callchain_user_64() clearly shows that stack pointer register is gpr[1]. Fix libbpf's definition of __PT_SP_REG for powerpc to fix all this. [0] https://kojipkgs.fedoraproject.org/work/tasks/1544/137921544/build.log Fixes: 138d6153a139 ("samples/bpf: Enable powerpc support") Signed-off-by: Andrii Nakryiko Reviewed-by: Naveen N Rao (AMD) Link: https://lore.kernel.org/r/20251020203643.989467-1-andrii@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin

libbpf: Fix some typos in comments

2024-09-09T23:05:40Z

Fix some spelling errors in the code comments of libbpf: betwen -> between paremeters -> parameters knowning -> knowing definiton -> definition compatiblity -> compatibility overriden -> overridden occured -> occurred proccess -> process managment -> management nessary -> necessary Signed-off-by: Yusheng Zheng Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240909225952.30324-1-yunwei356@gmail.com

libbpf: Fixed getting wrong return address on arm64 architecture

2024-09-09T22:56:22Z

ARM64 has a separate lr register to store the return address, so here you only need to read the lr register to get the return address, no need to dereference it again. Signed-off-by: Shuyi Cheng Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/1725787433-77262-1-git-send-email-chengshuyi@linux.alibaba.com

libbpf: fix some typos in libbpf

2024-09-05T20:07:47Z

Hi, fix some spelling errors in libbpf, the details are as follows: -in the code comments: termintaing->terminating architecutre->architecture requring->requiring recored->recoded sanitise->sanities allowd->allowed abover->above see bpf_udst_arg()->see bpf_usdt_arg() Signed-off-by: Lin Yikai Link: https://lore.kernel.org/r/20240905110354.3274546-3-yikai.lin@vivo.com Signed-off-by: Alexei Starovoitov

libbpf: Fix accessing first syscall argument on RV64

2024-09-05T00:06:39Z

On RV64, as Ilya mentioned before [0], the first syscall parameter should be accessed through orig_a0 (see arch/riscv64/include/asm/syscall.h), otherwise it will cause selftests like bpf_syscall_macro, vmlinux, test_lsm, etc. to fail on RV64. Let's fix it by using the struct pt_regs style CO-RE direct access. Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20220209021745.2215452-1-iii@linux.ibm.com [0] Link: https://lore.kernel.org/bpf/20240831041934.1629216-5-pulehui@huaweicloud.com

libbpf: Access first syscall argument with CO-RE direct read on arm64

2024-09-05T00:06:06Z

Currently PT_REGS_PARM1 SYSCALL(x) is consistent with PT_REGS_PARM1_CORE SYSCALL(x), which will introduce the overhead of BPF_CORE_READ(), taking into account the read pt_regs comes directly from the context, let's use CO-RE direct read to access the first system call argument. Suggested-by: Andrii Nakryiko Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Acked-by: Xu Kuohai Link: https://lore.kernel.org/bpf/20240831041934.1629216-3-pulehui@huaweicloud.com

libbpf: Access first syscall argument with CO-RE direct read on s390

2024-09-05T00:05:30Z

Currently PT_REGS_PARM1 SYSCALL(x) is consistent with PT_REGS_PARM1_CORE SYSCALL(x), which will introduce the overhead of BPF_CORE_READ(), taking into account the read pt_regs comes directly from the context, let's use CO-RE direct read to access the first system call argument. Suggested-by: Andrii Nakryiko Signed-off-by: Pu Lehui Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240831041934.1629216-2-pulehui@huaweicloud.com

libbpf: Avoid casts from pointers to enums in bpf_tracing.h

2024-05-03T05:58:58Z

[Differences from V1: - Do not introduce a global typedef, as this is a public header. - Keep the void* casts in BPF_KPROBE_READ_RET_IP and BPF_KRETPROBE_READ_RET_IP, as these are necessary for converting to a const void* argument of bpf_probe_read_kernel.] The BPF_PROG, BPF_KPROBE and BPF_KSYSCALL macros defined in tools/lib/bpf/bpf_tracing.h use a clever hack in order to provide a convenient way to define entry points for BPF programs as if they were normal C functions that get typed actual arguments, instead of as elements in a single "context" array argument. For example, PPF_PROGS allows writing: SEC("struct_ops/cwnd_event") void BPF_PROG(cwnd_event, struct sock *sk, enum tcp_ca_event event) { bbr_cwnd_event(sk, event); dctcp_cwnd_event(sk, event); cubictcp_cwnd_event(sk, event); } That expands into a pair of functions: void ____cwnd_event (unsigned long long *ctx, struct sock *sk, enum tcp_ca_event event) { bbr_cwnd_event(sk, event); dctcp_cwnd_event(sk, event); cubictcp_cwnd_event(sk, event); } void cwnd_event (unsigned long long *ctx) { _Pragma("GCC diagnostic push") _Pragma("GCC diagnostic ignored \"-Wint-conversion\"") return ____cwnd_event(ctx, (void*)ctx[0], (void*)ctx[1]); _Pragma("GCC diagnostic pop") } Note how the 64-bit unsigned integers in the incoming CTX get casted to a void pointer, and then implicitly converted to whatever type of the actual argument in the wrapped function. In this case: Arg1: unsigned long long -> void * -> struct sock * Arg2: unsigned long long -> void * -> enum tcp_ca_event The behavior of GCC and clang when facing such conversions differ: pointer -> pointer Allowed by the C standard. GCC: no warning nor error. clang: no warning nor error. pointer -> integer type [C standard says the result of this conversion is implementation defined, and it may lead to unaligned pointer etc.] GCC: error: integer from pointer without a cast [-Wint-conversion] clang: error: incompatible pointer to integer conversion [-Wint-conversion] pointer -> enumerated type GCC: error: incompatible types in assigment (*) clang: error: incompatible pointer to integer conversion [-Wint-conversion] These macros work because converting pointers to pointers is allowed, and converting pointers to integers also works provided a suitable integer type even if it is implementation defined, much like casting a pointer to uintptr_t is guaranteed to work by the C standard. The conversion errors emitted by both compilers by default are silenced by the pragmas. However, the GCC error marked with (*) above when assigning a pointer to an enumerated value is not associated with the -Wint-conversion warning, and it is not possible to turn it off. This is preventing building the BPF kernel selftests with GCC. This patch fixes this by avoiding intermediate casts to void*, replaced with casts to `unsigned long long', which is an integer type capable of safely store a BPF pointer, much like the standard uintptr_t. Testing performed in bpf-next master: - vmtest.sh -- ./test_verifier - vmtest.sh -- ./test_progs - make M=samples/bpf No regressions. Signed-off-by: Jose E. Marchesi Signed-off-by: Andrii Nakryiko Link: https://lore.kernel.org/bpf/20240502170925.3194-1-jose.marchesi@oracle.com

libbpf: Fix syscall access arguments on riscv

2023-10-04T20:19:13Z

Since commit 08d0ce30e0e4 ("riscv: Implement syscall wrappers"), riscv selects ARCH_HAS_SYSCALL_WRAPPER so let's use the generic implementation of PT_REGS_SYSCALL_REGS(). Fixes: 08d0ce30e0e4 ("riscv: Implement syscall wrappers") Signed-off-by: Alexandre Ghiti Signed-off-by: Andrii Nakryiko Reviewed-by: Sami Tolvanen Link: https://lore.kernel.org/bpf/20231004110905.49024-2-bjorn@kernel.org

libbpf: Use local includes inside the library

2023-08-04T22:06:46Z

In our monrepo, we try to minimize special processing when importing (aka vendor) third-party source code. Ideally, we try to import directly from the repositories with the code without changing it, we try to stick to the source code dependency instead of the artifact dependency. In the current situation, a patch has to be made for libbpf to fix the includes in bpf headers so that they work directly from libbpf/src. Signed-off-by: Sergey Kacheev Acked-by: Yonghong Song Link: https://lore.kernel.org/r/CAJVhQqUg6OKq6CpVJP5ng04Dg+z=igevPpmuxTqhsR3dKvd9+Q@mail.gmail.com Signed-off-by: Martin KaFai Lau