如果BPF_CLASS(code)等于BPF_JMP或BPF_JMP32,则BPF_OP(code)是以下之一: BPF_JA0x00/* BPF_JMP only */BPF_JEQ0x10BPF_JGT0x20BPF_JGE
BPF_SRC(code) == BPF_X - use 'src_reg' register as source operand BPF_SRC(code) == BPF_K - use 32-bit immediate as source operand 也就是说,操作数的选择上,BPF_K代表使用立即数,BPF_X代表使用源寄存器的内容。 如果BPF_CLASS(code)等于BPF_ALU或BPF_ALU64,则BPF_OP(code)是以下之一: BP...
经过Code Generation & IR Builder模块的处理,AST会被转化成LLVM IR,具体处理如下图所示。 LLVM IR也可以通过bpftrace -d打印出来。 4. LLVM IR → BPF bytecode 如何把LLVM IR转成BPFbytecode, 这里就用到了LLVM编译器。下图是BPF bytecode指令的格式, BFP_CALL&JMP组合是0x85, get_current_pid_tgid对应的...
还用宏生成了一个名字为license的section 3.2.BPF程序中的字节码(bytecode) 可以用objdump工具查看 可见是将我们的bpf程序编译到elf文件的某个节中,右边黄框内就是常说的bpf字节码,对应左边灰色内容 接下来讲一下,bpf程序是如何转成字节码的 3.3.BPF内核辅助函数调用转换为BPF字节码的过程 我们用到的BPF内核辅助...
BPF code:#include <linux/ip.h>int filter(struct __sk_buff*skb) { struct iphdr*ip = bpf_hdr_pointer(skb); if (ip->saddr == 0xc0a80101) { return 1; } return 0; } 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 甘特图
Code-Survey: Uncovering Insights in Large-Scale Codebases with LLM Do we truly understand how complex systems, like the Linux kernel, work? How can we grasp the high-level design choices and evolution of such intricate systems? Code-Survey is the first step in using LLMs to gain meaningful...
Notes on BPF (5) - BPF bytecodes and the BPF verifier Oracle Linux kernel developer Alan Maguire presents this six-part series on BPF, wherein he presents an in depth look at the kernel's "Berkeley Packet Filter" -- a useful and extensible kernel functio
clean:rm-f*.o*.so $(EXECABLE)build:${BPFCODE.c}${BPFLOADER}$(CLANG)-O2-target bpf-c $(BPFCODE:=.c)$(CCINCLUDE)-o ${BPFCODE:=.o}bpfload:build clang-o $(EXECABLE)-lelf $(LOADINCLUDE)$(LIBRARY_PATH)$(BPFSO)\ $(BPFLOADER)load1.c ...
Code Issues Pull requests Discussions Capstone disassembly/disassembler framework for ARM, ARM64 (ARMv8), Alpha, BPF, Ethereum VM, HPPA, LoongArch, M68K, M680X, Mips, MOS65XX, PPC, RISC-V(rv32G/rv64G), SH, Sparc, SystemZ, TMS320C64X, TriCore, Webassembly, XCore and X86. ...
/* (1.4) 如果加载BPF_PROG_TYPE_KPROBE类型的BPF程序,指定的内核版本需要和当前内核版本匹配。不然由于内核的改动,可能会附加到错误的地址上。*/if (type == BPF_PROG_TYPE_KPROBE &&attr->kern_version != LINUX_VERSION_CODE)return -EINVAL;