Re: symbol table
In message: <[EMAIL PROTECTED]> Erik Trulsson <[EMAIL PROTECTED]> writes: : On Sun, Apr 20, 2008 at 12:02:09PM +0300, emily becker wrote: : > Hi, : > : > I have a question about symbol table. : > One of the section In symbol table is memory adress which symbol is located. : > I wonder if this memory adress is bound at run-time or compile-time? : : It depends. Symbols referring to objects in a dynamically loaded library : will be bound at run-time, the rest should be bound at compile-time. They are bound at link-time, not compile-time. This is splitting a fine hair, but compile-time is when a .o or .so is created, while link time combines .o-like things together into a bigger thing. When that bigger thing is a final link, the addresses for the static portions of the binary are set. When the final thing is a dynamic library, the addresses float (since all the code is PIC anyway, they don't really matter). Dynamic parts of executables are bound at run-time. : > if it is compile-time, I don't understand how do we know whether the symbol : > is located this adress. : > Maybe this adress is already bound by other process or like this. : : Each process runs in its own address space, and therefore the compiler : (actually: the linker) can know exactly where in this address space things : will end up. The run-time linker (ld.so) is the one that knows where things wind up in a given process... libc.so and other shared libraries can and do link at different addresses for different processes. Warner ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: symbol table
In message: <[EMAIL PROTECTED]> "emily becker" <[EMAIL PROTECTED]> writes: : Hi, : : I have a question about symbol table. : One of the section In symbol table is memory adress which symbol is located. : I wonder if this memory adress is bound at run-time or compile-time? Typically, run-time, but there are exceptions. : if it is compile-time, I don't understand how do we know whether the symbol : is located this adress. The exceptions are for things like 'start' which live at a fixed address by the ELF ABI specification for most processors. Warner ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: Yarrow's Counter
On Sat, 19 Apr 2008 23:30:23 +0400 Eygene Ryabinkin <[EMAIL PROTECTED]> wrote: > I would not do it without consultations with Yarrow's creators: OK, I didn't realise it was actually specified, I thought it an implementation detail. > this modification seems not to help anything, It possibly doesn't help with an attack against Yarrow itself, but it means that 512 bits of entropy, rather than 256 bits, can be read-out from /dev/random. ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: symbol table
On Sun, Apr 20, 2008 at 12:02:09PM +0300, emily becker wrote: > Hi, > > I have a question about symbol table. > One of the section In symbol table is memory adress which symbol is located. > I wonder if this memory adress is bound at run-time or compile-time? It depends. Symbols referring to objects in a dynamically loaded library will be bound at run-time, the rest should be bound at compile-time. > if it is compile-time, I don't understand how do we know whether the symbol > is located this adress. > Maybe this adress is already bound by other process or like this. Each process runs in its own address space, and therefore the compiler (actually: the linker) can know exactly where in this address space things will end up. (The above is true for FreeBSD and just about all other Unix-derived systems. Other systems can do things differently.) -- Erik Trulsson [EMAIL PROTECTED] ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
symbol table
Hi, I have a question about symbol table. One of the section In symbol table is memory adress which symbol is located. I wonder if this memory adress is bound at run-time or compile-time? if it is compile-time, I don't understand how do we know whether the symbol is located this adress. Maybe this adress is already bound by other process or like this. I look forward to answers thank you ___ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "[EMAIL PROTECTED]"
