System.map documents upgrade

I located that System.map documents has addresses of icons. Does it entail system telephone calls? I read that it is just upgraded when a new kernel is freshly assembled.

So does that suggests that with the exception of a new kernel collection, these are constantly saved in the very same address?

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2019-05-13 04:38:52
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System.map has a symbol table, i.e. a checklist of function names in the Linux kernel, with for each and every function the address at which its code is filled in memory (the addresses are not physical addresses, they remain in the kernel is address room, like any kind of executable icon table remains in the crammed procedure address room). This isn't restricted to system telephone calls (the user interfaces revealed to customer procedures) : the documents additionally details features that could be called by a crammed component, and also also inner features. The system calls are the icons whose name starts with sys_.

The addresses are linked to a certain kernel binary (vmlinux, bzImage or various other layout ; the photo layout does not transform the addresses, it is simply an encoding) ; they are reproducible for an offered kernel resource, arrangement and also compiler. The documents is created by scripts/mksysmap near completion of the kernel construct procedure ; it is the result of the nm command.

The documents is made use of mostly for debugging, yet it is additionally read when assembling some 3rd - event components that make use of unpredictable kernel user interfaces (unpredictable as in transforming from one variation to the next).

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2019-05-17 16:37:41
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