Re: Potential bug in fs/binfmt_elf.c?

[John Reiser]

> >  LOAD           0x001000 0x00400000 0x00400000 0x00000 0x10000000 R   0x1000
>
>
> What is the purpose of allocating 256MB of read-only zeros?

To prevent the kernel from placing any shared libraries there [via mmap()
from ld-linux.so.2], especially under the influence of exec-shield.
This is 'wine', which wants to reserve that address space for mapping
executables that were built for some other operating system.  For this
purpose, the .p_flags of PF_R instead could be 0 [==> PROT_NONE]; but
do_brk() still turns either one into 'prw.' which has potential memory
[over-]commit charges.  The expected 'pr--' [or 'p---'] should have
a memory commit cost of zero.

--

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/