RFC: Adding non-PIC executable support to MIPS

Mark Mitchell mark@codesourcery.com
Sun Jul 27 23:48:00 GMT 2008


Richard Sandiford wrote:
> Daniel Jacobowitz <dan@debian.org> writes:
>> All comments welcome - Richard, especially from you.  How would you
>> like to proceed?  I think the first step should be to get your other
>> binutils/gcc patches merged, including MIPS16 PIC; I used those as a
>> base.  But see a few of the notes for potential problems with those
>> patches.
> 
> Yeah, Nick's approved most of the remaining binutils changes (thanks).
> I haven't applied them yet because of the doubt over whether st_size
> should be even or odd for ISA-encoded MIPS16 symbols.  I don't really
> have an opinion, so I'll accept a maintainerly decision...

[I'm not sure if this is a helpful suggestion or not, so feel free to 
ignore it if it's not.]

I would suggest that st_size be the actual size of the function, as it 
lives in memory.  A test of it's start/end location is "could I stick a 
random data byte there and have it affect the function".  For example, 
for a Thumb function whose ISA address is "0x00000001", I would consider 
for size purposes that it starts at "0x00000000", since altering that 
byte at run-time would change the meaning of the function.

-- 
Mark Mitchell
CodeSourcery
mark@codesourcery.com
(650) 331-3385 x713



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