On 01/13, Will Drewry wrote: > > On Fri, Jan 13, 2012 at 1:01 PM, Will Drewry <wad@xxxxxxxxxxxx> wrote: > > On Fri, Jan 13, 2012 at 11:31 AM, Oleg Nesterov <oleg@xxxxxxxxxx> wrote: > >> > >> Me too. I see no point in using user_regs_struct. > > > > I'll rev the change to use pt_regs and drop all the helper code. If > > no one says otherwise, that certainly seems ideal from a performance > > perspective, and I see pt_regs exported to userland along with ptrace > > abi register offset macros. > > On second thought, pt_regs is scary :) > > From looking at > http://lxr.linux.no/linux+v3.2.1/arch/x86/include/asm/syscall.h#L97 > and ia32syscall enty code, it appears that for x86, at least, the > pt_regs for compat processes will be 8 bytes wide per register on the > stack. This means if a self-filtering 32-bit program runs on a 64-bit host in > IA32_EMU, its filters will always index into pt_regs incorrectly. Yes, thanks, I forgot about compat tasks again. But this is easy, just we need regs_64_to_32(). Doesn't matter. I think Indan has a better suggestion. Oleg. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
