Hi Ralf,
On 7/19/07, Ralf Baechle <ralf@xxxxxxxxxxxxxx> wrote:
On Thu, Jul 19, 2007 at 09:10:23AM +0200, Franck Bui-Huu wrote:
> This patch adds a page size range randomisation to the user
> stack pointer.
Looks fine to me aside of the issue Nigel raised.
I'll fix it.
There is a constant defining the ABI-specific alignment in <asm/asm.h>:
I didn't know about them. ALSZ name is not really self speaking, don't
you think ?
#if (_MIPS_SIM == _MIPS_SIM_ABI32)
#define ALSZ 7
#define ALMASK ~7
#endif
#if (_MIPS_SIM == _MIPS_SIM_NABI32) || (_MIPS_SIM == _MIPS_SIM_ABI64)
#define ALSZ 15
#define ALMASK ~15
#endif
this is weird I would have defined them like this instead:
#if (_MIPS_SIM == _MIPS_SIM_ABI32)
#define ALSZ 8
#elif (_MIPS_SIM == _MIPS_SIM_NABI32) || (_MIPS_SIM == _MIPS_SIM_ABI64)
#define ALSZ 16
#endif
#define ALMASK (~(ALSZ-1))
This will unnecessarily increase the alignment of the stack wasting a few
bytes of memory for O32 binaries running on 64-bit kernels but I'd just
ignore this artefact; the cure would be uglier than the disease ;-)
specially that we don't care to waste a couple of bytes in this case...
Thanks
--
Franck
