kallsyms是否具有内核功能的所有符号?

问题描述

在Linux内核中，我想探究内核功能effective_prio().它定义为static.当我在 kallsyms 中搜索它的符号时，找不到它. kallsyms 是否具有内核功能的所有符号?如果没有，哪些符号不包括在内?

In the Linux kernel I want to probe the kernel function effective_prio(). It defined as static.When I go to search the symbol of it in the kallsyms I cannot find it. Does kallsyms have all the symbol of the kernel functions? If not, which symbols are not included?

推荐答案

对于在/proc/kallsyms中不出现的功能，有两种可能性:

There are two possibilities for a function not appearing in /proc/kallsyms:

1. 如果该功能被标记为static，并且编译器决定内联该功能(带有或不带有inline关键字)

2. 如果一个配置选项或另一个#define从编译中删除了一个函数，例如:

1. If the function is marked as static, and the compiler decides to inline the function (with or without the inline keyword)

2. If a config option or another #define removes a function from being compiled, e.g.:

#ifdef CONFIG_OPT
void foo(void) {
}
#endif

据我所知，如果一个功能没有出现在/proc/kallsyms中，则不可能从模块中调用或探测它.但是，/proc/kallsyms包含内核的所有功能，而不仅仅是通过EXPORT_SYMBOL/EXPORT_SYMBOL_GPL导出的功能.

As far as I know, if a function does not appear in /proc/kallsyms, it is not possible to call or probe it from a module.However, /proc/kallsyms contains all functions of the kernel, not just the ones exported via EXPORT_SYMBOL/EXPORT_SYMBOL_GPL.

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