PATCH: Map GNU attributes section to PT_GNU_ATTR (aka PT_GNU_STACK) segment

[Daniel Jacobowitz]

On Thu, Aug 16, 2007 at 05:54:55AM -0700, H.J. Lu wrote:
>   GNU_ATTR       0x008004 0x00000000 0x00000000 0x0002c 0x00000 RW  0x1
> 
>  Section to Segment mapping:
>   Segment Sections...
>    00     .text
>    01     .ARM.attributes
> [hjl@gnu-6 attr-1]$
> 
> Run-time loader can access the attribute section by checking offset
> and filesize without making it SEC_ALLOC.

Because you now have a non-allocated section that you want the runtime
loader to look at.  There's no guarantee that it is mapped in memory
anywhere after mapping the PT_LOAD segments.  Forcing the runtime
loader to make an extra mmap to get at the attributes basically
ensures that glibc's loader won't do so - that's at least one extra
syscall for every loaded object.

How are you planning to use this in the loader, and have you discussed
it with the glibc maintainers at all?

-- 
Daniel Jacobowitz
CodeSourcery