C++ 如何计算ELF程序头的虚拟地址？

我已经写了一些汇编指令文件，我想让它们可以执行。然而，我把程序标题搞砸了。我已经阅读了关于精灵头的整个手册页，但我不太明白

#include <elf.h>
#include <unistd.h>
#include <fcntl.h>
#include <sys/stat.h>


void MakeExecutable(char *codeBuffer, char *startAddr, unsigned int codeSize){
    char *fileBuffer = (char*) malloc(2058);
    memset(fileBuffer, 0, 2058);

    //I've omitted the sections declaration

    unsigned int codeOffset = sizeof(Elf64_Ehdr) + (unsigned int ) (startAddr - codeBuffer);


    Elf64_Ehdr *h = (Elf64_Ehdr*) &fileBuffer[0];
    h->e_ident[0] = 0x7f;
    h->e_ident[1] = 0x45;
    h->e_ident[2] = 0x4c;
    h->e_ident[3] = 0x46;
    h->e_ident[EI_CLASS] = ELFCLASS64;
    h->e_ident[EI_DATA]  = ELFDATA2LSB;  
    h->e_ident[EI_VERSION]  = EV_CURRENT; 
    h->e_ident[EI_OSABI]  = ELFOSABI_SYSV;
    h->e_type    = ET_DYN;
    h->e_machine = EM_X86_64;
    h->e_version = EV_CURRENT;
    h->e_entry   = 64;
    h->e_phentsize = sizeof(Elf64_Phdr);
    h->e_shentsize = sizeof(Elf64_Shdr);
    h->e_shoff   = 0;
    h->e_phoff   = 800;
    h->e_shnum   = 0;
    h->e_phnum   = 1;
    h->e_shstrndx= 0;

    h->e_ehsize     = sizeof(Elf64_Ehdr);

    Elf64_Phdr *ph = (Elf64_Phdr*) &fileBuffer[800];
    ph->p_type = PT_LOAD;
    ph->p_vaddr = 0x8050000;
    ph->p_paddr = 0;
    ph->p_offset = 0x4000;
    ph->p_memsz  = 2058;
    ph->p_flags  = PF_X | PF_R | PF_W;
    ph->p_filesz = 2058;
    ph->p_align = 0x100000;

    int file = open("ex.out", O_TRUNC | O_RDWR, S_IRWXO | S_IRWXU | S_IRWXG );
    int error = write(file, fileBuffer, 2058);
    close(file);
}

它确实为我分配了4096字节的页面，那么这里会有什么问题呢？这是objdump

ex.out:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <.text>:
   0:   55                      push   %rbp
   1:   48 89 e5                mov    %rsp,%rbp
   4:   48 81 ec 01 00 00 00    sub    $0x1,%rsp
   b:   8a 85 10 00 00 00       mov    0x10(%rbp),%al
  11:   88 85 ff ff ff ff       mov    %al,-0x1(%rbp)
  17:   49 c7 c1 00 00 00 00    mov    $0x0,%r9
  1e:   49 c7 c0 00 00 00 00    mov    $0x0,%r8
  25:   49 c7 c2 00 00 00 00    mov    $0x0,%r10
  2c:   48 c7 c2 00 00 00 00    mov    $0x0,%rdx
  33:   48 c7 c6 00 00 00 00    mov    $0x0,%rsi
  3a:   48 c7 c7 00 00 00 00    mov    $0x0,%rdi
  41:   48 c7 c0 3c 00 00 00    mov    $0x3c,%rax
  48:   0f 05                   syscall 
  4a:   48 89 ec                mov    %rbp,%rsp
  4d:   5d                      pop    %rbp
  4e:   c3                      retq 

ex.out:文件格式elf64-x86-64
第节的分解。正文：
0000000000000000 :
0:55推送%rbp
1:48 89 e5 mov%rsp，%rbp
4:48 81 ec 01 00 00分$0x1，%rsp
b:8a 85 10 00 mov 0x10（%rbp），%al
11:88 85 ff移动%al，-0x1（%rbp）
17:49 c7 c1 00 mov$0x0，%r9
1e:49 c7 C000 mov$0x0，%r8
25:49 c7 c2 00 mov$0x0，%r10
2c:48 c7 c2 00 mov$0x0，%rdx
33:48 c7 C600 mov$0x0，%rsi
3a:48 c7 c7 00 mov$0x0，%rdi
41:48 c7 c0 3c 00 mov$0x3c，%rax
48:0f 05系统调用
4a:48 89 ec mov%rbp，%rsp
4d:5d pop%rbp
4e:c3 retq

另外，当我尝试使用它运行

gdb

时，它也会出现分段错误： '程序收到信号SIGSEGV，分段故障。 0x00007fffeffae040英寸？？？”

编辑

---

此外，如果我将p_vaddr设置为0，则不会出现分段错误，但是代码的行为与预期不符。例如，如果我在代码上放了一条打印指令，则在执行文件时，命令行上不会打印任何内容。

代码段不使用

codeBuffer

，也不使用

codefset

。请提供代码段不使用

codeBuffer

，也不使用

codecoffset

。请提供

ex.out:     file format elf64-x86-64


Disassembly of section .text:

0000000000000000 <.text>:
   0:   55                      push   %rbp
   1:   48 89 e5                mov    %rsp,%rbp
   4:   48 81 ec 01 00 00 00    sub    $0x1,%rsp
   b:   8a 85 10 00 00 00       mov    0x10(%rbp),%al
  11:   88 85 ff ff ff ff       mov    %al,-0x1(%rbp)
  17:   49 c7 c1 00 00 00 00    mov    $0x0,%r9
  1e:   49 c7 c0 00 00 00 00    mov    $0x0,%r8
  25:   49 c7 c2 00 00 00 00    mov    $0x0,%r10
  2c:   48 c7 c2 00 00 00 00    mov    $0x0,%rdx
  33:   48 c7 c6 00 00 00 00    mov    $0x0,%rsi
  3a:   48 c7 c7 00 00 00 00    mov    $0x0,%rdi
  41:   48 c7 c0 3c 00 00 00    mov    $0x3c,%rax
  48:   0f 05                   syscall 
  4a:   48 89 ec                mov    %rbp,%rsp
  4d:   5d                      pop    %rbp
  4e:   c3                      retq