blocks|key|3723548|text|语法问题..。Nasm将使用"$+%2B+5"，(G)将使用".+%2B+5"，也可能需要"$“(？)。我从最初的标签上了解到，我们在使用纳玛斯？那么"$+%2B+5“应该是正确的，但可能不会做你想做的事情。asm语法将是"jmp目标“(或用于Gas的"jmp+$target”)，您将在反汇编中看到同样的情况.但是仔细看看正在生成的字节。"jmp“操作码后面是”距离目标“，而不是”目标“！如果您想编码“距离到目标”，我认为您需要使用"db+0xE8“(或适当的操作码)，然后是"db+(或dw或dd)+0x??”(我认为“.byte”或".long“表示天然气)。这可能不是你想做的。重新考虑你的密码。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|3723549|最好，弗兰克|3723550|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|F|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|G|8|@]|9|@]|A|$]]|$1|D|3|-4|5|6|7|H|8|@]|9|@]|A|$]]]|E|$]]

Syntax issue... Nasm would use "$ + 5", (G)as would use ". + 5", and might need a "$" as well(?). I understand from the original tag, that we're using Nasm? Then "$ + 5" should be correct, but probably won't do what you want. The asm syntax would be "jmp target" (or "jmp $target" for Gas?), and you'll see the same thing in a disassembly... but look closely at the bytes being generated. The "jmp" opcode is followed by "distance to target", not "target"! If you want to code "distance to target", I think you'll need to resort to "db 0xE8" (or appropriate opcode) followed by "db (or dw or dd) 0x??" (".byte" or ".long" for Gas, I think). This probably isn't what you want to do. Re-think your code.

Best,
Frank

blocks|key|2843355|text|您可以使用相对跳转，例如|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2843356|jmp+$%2B5|code-block|syntax|javascript|2843357|它相对于跳跃的开始。|2843358|entityMap^0|0|0|0^^$0|@$1|2|3|4|5|6|7|K|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|L|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|M|8|@]|9|@]|A|$]]|$1|I|3|-4|5|6|7|N|8|@]|9|@]|A|$]]]|J|$]]

You can use a relative jump like

<pre><code>jmp $+5
</code></pre>

It relative to the start of the jump.

blocks|key|2864486|text|下面是我为好玩而做的一个例子。(使用NASM)|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2864487|BITS+32
segment+.text
global+_start
_start:
++++jmp+tmp
++++PUSH+0x68732f
++++PUSH+0x6e69622f
++++LEA+EBX,[ESP]
++++;+...
_jumpstop:
++++tmp+equ+($+-+_start)|code-block|syntax|javascript|2864488|这样，一旦被编译，它就变成了|2864489|00000000++E90D000000++++++++jmp+0x12
00000005++682F736800++++++++push+dword+0x68732f
0000000A++682F62696E++++++++push+dword+0x6e69622f
0000000F++8D1C24++++++++++++lea+ebx,[esp]|2864490|因此跳转在lea+ebx,[esp]之后立即着陆|offset|length|style|CODE|2864491|entityMap^0|0|0|0|0|5|D|0^^$0|@$1|2|3|4|5|6|7|S|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|T|8|@]|9|@]|A|$E|F]]|$1|G|3|H|5|6|7|U|8|@]|9|@]|A|$]]|$1|I|3|J|5|D|7|V|8|@]|9|@]|A|$E|F]]|$1|K|3|L|5|6|7|W|8|@$M|X|N|Y|O|P]]|9|@]|A|$]]|$1|Q|3|-4|5|6|7|Z|8|@]|9|@]|A|$]]]|R|$]]

Here is an example usage I made for fun. (Uses NASM)
<pre><code>BITS 32
segment .text
global _start
_start:
 jmp tmp
 PUSH 0x68732f
 PUSH 0x6e69622f
 LEA EBX,[ESP]
 ; ...
_jumpstop:
 tmp equ ($ - _start)

</code></pre>
That way once it is compiled it becomes
<pre><code>00000000 E90D000000 jmp 0x12
00000005 682F736800 push dword 0x68732f
0000000A 682F62696E push dword 0x6e69622f
0000000F 8D1C24 lea ebx,[esp]
</code></pre>
So that the jump lands immediately after the <code>lea ebx,[esp]</code>

blocks|key|3723573|text|GAS和NASM没有语法直接设置rel8或rel32位移，只有目标地址。(例如，jmp+%2B0被解释为跳转到绝对地址0，或语法错误)。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|3723574|您可以使用.byte+/+.long+(GAS)或db+(NASM和大多数其他非GAS+x86汇编程序)手动编码它。注意，相对分支位移相对于分支指令的末尾。|3723575|++++db++0xEB,+0x01++++;+jmp+short+%2B1+++over+the+1-byte+nop
++++nop+++++++++++++++++++
+jump_target:++++
++++db++0xE9
++++++++dd++++-5+++++;++jmp+near+-5++++also+jump+backwards+to+jump_target,+i.e.+to+itself|code-block|syntax|javascript|3723576|(GAS与.byte和.long完全相同，而不是db和dd)|3723577|3723578|或使用语法描述相对于行开头的地址。|BOLD|3723579|jmp+short++$%2B3+++++++++++;+rel8+=+%2B1++++++NASM,+forcing+the+jmp+size+to+2+bytes

jmp++.%2B3+++++++++++++++++#+rel8+=+%2B1++++++GAS|3723580|How+does+$+work+in+NASM,+exactly?展示了手动编码分支以到达给定目标、从目标地址减去$+(当前输出位置)和调整分支长度的示例。|3723581|在这里，我们需要考虑分支长度，以获得所需的相对偏移量编码，因为$+%2B+x的参考点是指令的开始，而不是结束。我们可以在结尾处贴上标签：|3723582|+++jmp++.rel_anchor+%2B+123+++++++;+rel8=+%2B123+++NASM+local+label
.rel_anchor:

+++jmp++1f+%2B+123;+1:++++++++++++#+GAS+local+label+on+the+same+line+but+a+separate+statement
+1:+++++++++++++++++++++++++++++#+It+might+be+more+readable+to+put+the+label+here.|3723583|这实际上是有效的，我们从气体中得到eb+7b。|3723584|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/47494744/how-does-work-in-nasm-exactly^0|14|6|0|5|5|D|5|P|2|0|0|5|5|B|5|O|2|R|2|0|0|0|B|0|0|1L|1|0|X|0|0|V|5|0|0|H|5|0^^$0|@$1|2|3|4|5|6|7|1A|8|@$9|1B|A|1C|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|1D|8|@$9|1E|A|1F|B|C]|$9|1G|A|1H|B|C]|$9|1I|A|1J|B|C]]|D|@]|E|$]]|$1|H|3|I|5|J|7|1K|8|@]|D|@]|E|$K|L]]|$1|M|3|N|5|6|7|1L|8|@$9|1M|A|1N|B|C]|$9|1O|A|1P|B|C]|$9|1Q|A|1R|B|C]|$9|1S|A|1T|B|C]]|D|@]|E|$]]|$1|O|3|-4|5|6|7|1U|8|@]|D|@]|E|$]]|$1|P|3|Q|5|6|7|1V|8|@$9|1W|A|1X|B|R]]|D|@]|E|$]]|$1|S|3|T|5|J|7|1Y|8|@]|D|@]|E|$K|L]]|$1|U|3|V|5|6|7|1Z|8|@$9|20|A|21|B|C]]|D|@$9|22|A|23|1|24]]|E|$]]|$1|W|3|X|5|6|7|25|8|@$9|26|A|27|B|C]]|D|@]|E|$]]|$1|Y|3|Z|5|J|7|28|8|@]|D|@]|E|$K|L]]|$1|10|3|11|5|6|7|29|8|@$9|2A|A|2B|B|C]]|D|@]|E|$]]|$1|12|3|-4|5|6|7|2C|8|@]|D|@]|E|$]]]|13|$14|$5|15|16|17|E|$18|19]]]]

GAS and NASM don't have syntax to set the rel8 or rel32 displacement directly, only the target address. (e.g. <code>jmp +0</code> is interpreted as a jump to absolute address 0, or a syntax error).
You can encode it manually with <code>.byte</code> / <code>.long</code> (GAS) or <code>db</code> (NASM and most other non-GAS x86 assemblers). Note that the relative branch displacement is relative to the end of the branch instruction.
<pre><code> db 0xEB, 0x01 ; jmp short +1 over the 1-byte nop
 nop 
 jump_target: 
 db 0xE9
 dd -5 ; jmp near -5 also jump backwards to jump_target, i.e. to itself
</code></pre>
(GAS would be identical but with <code>.byte</code> and <code>.long</code> instead of <code>db</code> and <code>dd</code>)
<hr />
Or, use syntax for describing an address relative to the start of the line
<pre><code>jmp short $+3 ; rel8 = +1 NASM, forcing the jmp size to 2 bytes

jmp .+3 # rel8 = +1 GAS
</code></pre>
<a href="https://stackoverflow.com/questions/47494744/how-does-work-in-nasm-exactly">How does $ work in NASM, exactly?</a> shows an example of manually encoding a branch to reach a given target, subtracting <code>$</code> (the current output position) from the target address, and adjusting for the length of the branch.
Here we need to take the branch length into account to get the the desired relative offset encoded, because our reference point for <code>$ + x</code>is the start, not end of the instruction. We could put a label at the end:
<pre><code> jmp .rel_anchor + 123 ; rel8= +123 NASM local label
.rel_anchor:

 jmp 1f + 123; 1: # GAS local label on the same line but a separate statement
 1: # It might be more readable to put the label here.
</code></pre>
This does actually work, we get <code>eb 7b</code> from GAS.

How can I force the value of the relative offsets?
I know how to do: jmp label_name
Would like to do: jmp $0x01

relative offset jumps

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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如何才能强迫相对偏移量的值？我知道该怎么做：jmp label_name想做的事：jmp $0x01

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