执行二进制文件时出现“没有此文件或目录”错误,同时显示权限被拒绝

执行二进制文件时出现“没有此文件或目录”错误,同时显示权限被拒绝
I was just trying to execute a simple program **.c** program on **OPNESUSE-42.1** 
I did the following set of commands in which showing **Permission Denied** and also showing **relocatable** i am not able to understand that how it becomes relocatable file.

$ 文件数据大小.o

datasize.o:ELF 64 位 LSB 可重定位,x86-64,版本 1 (SYSV),未剥离

无法执行:-

./数据大小.o

bash:./datasize.o:权限被拒绝

即使使用 ldd

ldd 数据大小.o

ldd:警告:您没有“./datasize.o”的执行权限,该权限不是动态可执行文件

strace 的输出

strace ./datasize.o

execve("./datasize.o", ["./datasize.o"], [/* 87 vars */]) = -1 EACCES (Permission denied)
write(2, "strace: exec: Permission denied\n", 32strace: exec: Permission denied
) = 32
exit_group(1)                           = ?
+++ exited with 1 +++

readelf 的输出:-

readelf -a ./datasize.o 

ELF Header:
  Magic:   7f 45 4c 46 02 01 01 00 00 00 00 00 00 00 00 00 
  Class:                             ELF64
  Data:                              2's complement, little endian
  Version:                           1 (current)
  OS/ABI:                            UNIX - System V
  ABI Version:                       0
  Type:                              REL (Relocatable file)
  Machine:                           Advanced Micro Devices X86-64
  Version:                           0x1
  Entry point address:               0x0
  Start of program headers:          0 (bytes into file)
  Start of section headers:          1040 (bytes into file)
  Flags:                             0x0
  Size of this header:               64 (bytes)
  Size of program headers:           0 (bytes)
  Number of program headers:         0
  Size of section headers:           64 (bytes)
  Number of section headers:         13
  Section header string table index: 10

Section Headers:
  [Nr] Name              Type             Address           Offset
       Size              EntSize          Flags  Link  Info  Align
  [ 0]                   NULL             0000000000000000  00000000
       0000000000000000  0000000000000000           0     0     0
  [ 1] .text             PROGBITS         0000000000000000  00000040
       000000000000009c  0000000000000000  AX       0     0     1
  [ 2] .rela.text        RELA             0000000000000000  00000318
       0000000000000078  0000000000000018   I      11     1     8
  [ 3] .data             PROGBITS         0000000000000000  000000dc
       0000000000000000  0000000000000000  WA       0     0     1
  [ 4] .bss              NOBITS           0000000000000000  000000dc
       0000000000000000  0000000000000000  WA       0     0     1
  [ 5] .rodata           PROGBITS         0000000000000000  000000e0
       0000000000000087  0000000000000000   A       0     0     8
  [ 6] .comment          PROGBITS         0000000000000000  00000167
       0000000000000019  0000000000000001  MS       0     0     1
  [ 7] .note.GNU-stack   PROGBITS         0000000000000000  00000180
       0000000000000000  0000000000000000           0     0     1
  [ 8] .eh_frame         PROGBITS         0000000000000000  00000180
       0000000000000038  0000000000000000   A       0     0     8
  [ 9] .rela.eh_frame    RELA             0000000000000000  00000390
       0000000000000018  0000000000000018   I      11     8     8
  [10] .shstrtab         STRTAB           0000000000000000  000003a8
       0000000000000061  0000000000000000           0     0     1
  [11] .symtab           SYMTAB           0000000000000000  000001b8
       0000000000000138  0000000000000018          12     9     8
  [12] .strtab           STRTAB           0000000000000000  000002f0
       0000000000000023  0000000000000000           0     0     1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings), l (large)
  I (info), L (link order), G (group), T (TLS), E (exclude), x (unknown)
  O (extra OS processing required) o (OS specific), p (processor specific)

There are no section groups in this file.

There are no program headers in this file.

Relocation section '.rela.text' at offset 0x318 contains 5 entries:
  Offset          Info           Type           Sym. Value    Sym. Name + Addend
000000000023  000a00000002 R_X86_64_PC32     0000000000000000 uname - 4
000000000028  00050000000a R_X86_64_32       0000000000000000 .rodata + 0
00000000002d  000b00000002 R_X86_64_PC32     0000000000000000 puts - 4
000000000087  00050000000a R_X86_64_32       0000000000000000 .rodata + 48
000000000091  000c00000002 R_X86_64_PC32     0000000000000000 printf - 4

Relocation section '.rela.eh_frame' at offset 0x390 contains 1 entries:
  Offset          Info           Type           Sym. Value    Sym. Name + Addend
000000000020  000200000002 R_X86_64_PC32     0000000000000000 .text + 0

The decoding of unwind sections for machine type Advanced Micro Devices X86-64 is not currently supported.

Symbol table '.symtab' contains 13 entries:
   Num:    Value          Size Type    Bind   Vis      Ndx Name
     0: 0000000000000000     0 NOTYPE  LOCAL  DEFAULT  UND 
     1: 0000000000000000     0 FILE    LOCAL  DEFAULT  ABS datasize.c
     2: 0000000000000000     0 SECTION LOCAL  DEFAULT    1 
     3: 0000000000000000     0 SECTION LOCAL  DEFAULT    3 
     4: 0000000000000000     0 SECTION LOCAL  DEFAULT    4 
     5: 0000000000000000     0 SECTION LOCAL  DEFAULT    5 
     6: 0000000000000000     0 SECTION LOCAL  DEFAULT    7 
     7: 0000000000000000     0 SECTION LOCAL  DEFAULT    8 
     8: 0000000000000000     0 SECTION LOCAL  DEFAULT    6 
     9: 0000000000000000   156 FUNC    GLOBAL DEFAULT    1 main
    10: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND uname
    11: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND puts
    12: 0000000000000000     0 NOTYPE  GLOBAL DEFAULT  UND printf

No version information found in this file.

答案1

实际上,如果“.o”文件不是真正的“.o”文件,则可以执行它们。例如,如果您将“ls”复制到“ls.o”,则可以执行 ls.o,它将为您提供“ls”命令的输出。顺便说一句,@jaychris,您可能不想将编译的输出放入“C”源文件中。您可以,但就像有一个可执行文件“ls.o”一样,它可能会造成混淆。

我在原始帖子中没有看到任何内容表明用户尝试运行的文件具有可执行权限。如果作者可以执行“\ls -l datasize.o”,他们会显示该文件具有哪些权限。

请注意,如果它确实是可链接文件,则仅设置可执行位(使用“chmod +x datasize.o”)不会使其成为可以运行的程序。在这种情况下,如果 datasize.o 中包含“main”,您可以尝试 @jaychris 所暗示的内容...使用 gcc -o datasize datasize.c ...这不会生成可链接的“datasize.o”,但会尝试创建一个可执行文件并将其放在名为“datasize”的文件中(您仍然必须使用“chmod +x datasize”启用“可执行”权限)。

顺便说一句,您可能需要阅读“chmod”手册页(“man 1 chmod”)。

希望这可以帮助 (?)...

答案2

.o 文件无法执行。它们需要链接并创建最终的可执行文件。通常的方法是“gcc -o file.c”,或者编译和链接分步进行。

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