= *(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that mul�ples their size, and padding is added for the proper alignment. Because of this, the size of struct may o�en grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

*(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 10. Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

*(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 10. Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

*(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 10. Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

*(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 10. Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

*(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 10. Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

*(u64 *)(r10 -8) 7: (95) exit processed 8 insns (limit 131072), stack depth 8 10. Remove struct padding with aligning members by using #pragma pack. In modern compilers, data structures are aligned by memory efficiently. Structure members are aligned to memory address that multiples their size, and padding is added for the proper alignment. Because of this, the size of struct may often grow larger than | // |________________________| // | sector(4) | PADDING | <= address aligned to 8 // |____________|___________| with 4-byte PADDING. The BPF verifier in the kernel checks the stack boundary

that, when the pointer is used together with a basic data type that is less than 8 bytes, memory padding may occur, wasting memory space. As a result, the page table is refreshed frequently, memory access

Fragmentation Offset Time To Live Protocol Header Checksum Source Address Destination Address Options Padding Data 图 2.3-1、IP 封包的表头资料 在上面的图示中有个地方要注意，那就是『每一行所占用的位数为 32 bits』， 各个表头的内容分别介绍如下： Version(版本)宣告这个 的网络层相关封包与数据 - 58 - 本文档使用 书栈(BookStack.CN) 构建 等。 Padding(补齐项目)由于 Options 的内容不一定有多大，但是我们知道 IP 每个数据都必须要是 32 bits，所以，若 Options 的数据不足 32 bits 时，则由 padding 主动补齐。 你只要知道 IP 表头里面含有： TTL, Protocol, 来源地址与目标地址也就够了！而这个 Sequence Number Acknowledge Number Data Offset Reserved Code Window Checksum Urgent Pointer Options Padding Data 图 2.4-2、TCP 封包的表头资料 上图就是一个 TCP 封包的表头数据，各个项目以 Source Port, Destination Port 及 Code 算是比较重要