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Re: GDB remote debugging stub: Question about memory read


On Monday 27 September 2010 09:54:04, Niklas Quarfot Nielsen wrote:
> GDB tries to read 0x40 bytes starting at address 0xffffffff6effffc0, which (I guess) is from the RSP.
> Packet: mffffffff6effffc0,40
> 
> My question is:
> Why does GDB try to read 0x40 bytes, when there is only 0x20 bytes on the stack (RBP-RSP)?
> 
> The architecture is an AMD64 and the version of GDB is 7.1(x86_64-gnu-linux).
> 
> I appreciate any answer and/or clue to why GDB behaves like this.
> I have tried to look through the remote debugging source code of GDB, but this has not given me any answers.
> If needed, I can post debugging information from the target code in GDB.
> 

0x40 bytes is GDB's stack cache line size (dcache.c).
Try "(gdb) set stack-cache off".

-- 
Pedro Alves


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