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.
$ file datasize.o
datasize.o：可重定位的ELF 64位LSB，x86-64，版本1（SYSV），未剥离
无法执行：-
./datasize.o
bash：./datasize.o：权限被拒绝
即使有ldd
ldd datasize.o
ldd：警告：您没有动态可执行文件`./datasize.o'的执行权限
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.
实际上，如果“ .o”文件不是真正的“ .o”文件，则可以执行它们。即，如果将“ 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，但是就像拥有可执行文件“ ls.o”一样，这可能会令人困惑。
在原始发布中，我没有看到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”，则他们将显示对其具有的权限。
请注意，仅设置可执行位（使用“ chmod + x datasize.o”），就不会使其成为可运行的程序（如果它确实是可链接文件）。在这种情况下，如果datasize.o中包含“ main”，则可以尝试@jaychris暗示的内容...使用gcc -o datasize datasize.c ...不会生成可链接的“ datasize.o” ”，但将尝试创建可执行文件并将其放入名为“ datasize”的文件中（您仍必须使用“ chmod + x datasize”启用“可执行”权限）。
顺便说一句，您可能想阅读“ chmod”联机帮助页（“ man 1 chmod”）。
希望这可以帮助 （？）...
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我来说两句