如何解释 ncval 的输出？

发布于 2025-01-07 02:02:53 字数 961 浏览 2 评论 0原文

我正在尝试将一些软件移植到本机客户端。出于速度原因，它在代码中的多个位置使用一些内联汇编。（它们中的大多数都是非常简单的一行代码，它们非常简单，应该被认为是安全的。）

我让项目进行编译和链接，但目前它无法通过 Chrome 的代码分析。 Ncval 输出以下内容：

segment[0] p_type 6 p_offset 0 vaddr 0 paddr 0 align 4
    filesz b4 memsz b4 flags 4
segment[1] p_type 1 p_offset 10000 vaddr 20000 paddr 20000 align 65536
    filesz 2e91a0 memsz 2e91a0 flags 5
parsing segment 1
VALIDATOR: 31be8: Illegal instruction
segment[2] p_type 1 p_offset 300000 vaddr 10020000 paddr 10020000 align 65536
    filesz 72aac memsz 72aac flags 4
segment[3] p_type 1 p_offset 380000 vaddr 100a0000 paddr 100a0000 align 65536
    filesz 1cb8 memsz 29658 flags 6
*** client_x86_32.nexe IS UNSAFE ***
Validated client_x86_32.nexe
***  client_x86_32.nexe is UNSAFE ***

但我真的不知道这个输出意味着什么。我可以看到它至少发现了一条非法指令。我做了 client_x86_32.nexe 的 objdump，我试图根据 ncval 的输出找出非法指令的地址，但我做不到，因为我不知道如何根据ncval 输出。

欢迎任何帮助。

（与此同时，我将开始从代码中删除 asm 块，并希望找到有问题的块，以便我可以更正它以确保安全。）

原文

I am trying to port some software to native-client. It uses some inline asm at multiple locations in the code for speed reasons. (Most of them are really simple one-line ones, which are so simple that they should be considered safe.)

I got the project to compile and link, but at the moment it failes Chrome's code analysis. Ncval outputs the following:

segment[0] p_type 6 p_offset 0 vaddr 0 paddr 0 align 4
    filesz b4 memsz b4 flags 4
segment[1] p_type 1 p_offset 10000 vaddr 20000 paddr 20000 align 65536
    filesz 2e91a0 memsz 2e91a0 flags 5
parsing segment 1
VALIDATOR: 31be8: Illegal instruction
segment[2] p_type 1 p_offset 300000 vaddr 10020000 paddr 10020000 align 65536
    filesz 72aac memsz 72aac flags 4
segment[3] p_type 1 p_offset 380000 vaddr 100a0000 paddr 100a0000 align 65536
    filesz 1cb8 memsz 29658 flags 6
*** client_x86_32.nexe IS UNSAFE ***
Validated client_x86_32.nexe
***  client_x86_32.nexe is UNSAFE ***

But I don't really know what this output means. I can see that it found at least one illegal instruction. I did an objdump of client_x86_32.nexe, and I tried to figure out what the address of the illegal instruction(s?) is based on ncval's output, but I couldn't, because I don't know how to calculate it based on the ncval output.

Any help is welcome.

(In the meantime I will start removing asm blocks from the code, and hope I find the offending block, so that I can correct it to be safe.)

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