some symbols of libc may be resolved by RTLD internal entities.

[Alexander Kabaev]

On Tue, 30 Jan 2007 18:00:46 +0900
takawata at jp.freebsd.org wrote:

> Hi, 
> 
> It seems that some symbols in libc is resolved by libc entities
> which is linked with RTLD to implement it.
> 
> % nm -D ld-elf.so.1
> ...
> 000158ec T mmap
> 0000c4fc W mprotect
> 0000c4dc W munmap
> ...

It doesn't. rtld is a special beast and its symbols availability to
user programs is controlled by a special code in rtld. Look up
static func_ptr_type exports[] in rtld.c and see how it is used.

-- 
Alexander Kabaev
P.S. The proper way to control symbol visibility is to use version
script file when linking rtld-elf.so.1 in order to force all unintended
symbols to local scope. exports array is there for historical reasons.
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