Re: [Valgrind-developers] Valgrind callgrind failure

[Eliot M. <mo...@cs...>]

On 4/26/2024 4:40 PM, Carl Love via Valgrind-developers wrote:
> Paul:
> 
> On Power, there are only 6 arguments maximum for a system call.  They are passed in regs 3 to 8 and get
> mapped to args 1 to 6.  The mmap call has agruments:
> 
>     __addr, __len, __prot, __flags, __fd, __offset
> 
> So, it does seem a little strange for the first agument to be zero????  As I mentioned, I do see call that succeed where arg1 is zero  So, I am still missing something.
> 
>                               Carl

As I recall, an address of 0 to mmap means to allow the system to choose the
address.  This generally makes sense only if MAP_FIXED is not set.

Cheers - Eliot