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Register a signal handler in _dl_start
- From: wuxi <wuxi at fudan dot edu dot cn>
- To: glibc-help <libc-help at sourceware dot org>
- Date: Mon, 01 Sep 2008 18:32:48 +0800
- Subject: Register a signal handler in _dl_start
Hi
I am doing a research project on IA-64 and glibc-2.5. My goal is to
instrument the program to enable whole-program taint tracking.
For that purpose, I need to register a special handler to handle SIGSEGV
at the very start of any program, for I use unmapped area as the bitmap
for taint tracking.
My problem is, when I hook signal handler at _dl_start (very start of
the library, according to my study of code) to enable taint tracking for
dynamic linker, the special signal handler seems not work - that is,
when I run ld.so, it reports Segment fault directly without trapping
into my signal handler. However, I dump the code and discover the hook
function has been called before such access.
So, am I missing something here to register a signal handler for dynamic
linker?
Thanks
yours sincerely
Andrew