Hi Andi, PPC64 IA64 and S390 use variable size TASK_SIZE for 32 bit and 64 bit program. I feel it is hard to maintain if we try to audit TASK_SIZE use everywhere, because most of them are in generic code.
And maintaining those audit code in separate place is also a problem. E.g. in current 32 bit emulation code TASK_SIZE is defined as 0xfffffff in elf loading, but defined as 0xffffe000 in mmaping. How did that earlier patch break applications? Thanks Zou Nan hai > -----Original Message----- > From: Andi Kleen [mailto:[EMAIL PROTECTED] > Sent: Thursday, April 21, 2005 7:54 PM > To: Zou, Nanhai > Cc: Andi Kleen; [EMAIL PROTECTED]; linux-kernel@vger.kernel.org; Siddha, > Suresh B > Subject: Re: [discuss] [Patch] X86_64 TASK_SIZE cleanup - more comments > > > Another comment: > > In general I am not too happy about the variable size TASK_SIZE. > There was a patch for this earlier, but it broke 32bit emulation > completely. And I think it needs auditing of all uses of TASK_SIZE, > because I suspect there are more bugs lurking in it. > > The way hugetlb etc. mmap were supposed to be handled was to > let the mmap succeed and then check in the mmap wrapper > if any address is > 4GB and free it. Probably that code > has some problems or got broken (I think it worked at least > in 2.4, but there might have been regressions later) > > -Andi - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/