lkml.org 
[lkml]   [1998]   [Jul]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Progress! was: Re: Yet more VM writable swap-cached pages

WOW!!! Finally!! Proof that Linus *has* implimented time-travel in the
Linux kernel: He's now fixing bugs the day before they happen!

(yes, yes, I know.. I saw the timezones.. But's it's still funny)

On Thu, 9 Jul 1998, Linus Torvalds wrote:

>
>
> On Fri, 10 Jul 1998, Ganesh Sittampalam wrote:
> >
> > Since this is now 100% reproducible on my system, I'd be happy to
> > guinea-pig any fixes, however experimental.
>
> Does this fix it dor you?
>
> Linus
> -----
> diff -u --recursive --new-file v2.1.108/linux/include/asm-i386/pgtable.h linux/include/asm-i386/pgtable.h
> --- v2.1.108/linux/include/asm-i386/pgtable.h Wed Jun 24 22:54:10 1998
> +++ linux/include/asm-i386/pgtable.h Thu Jul 9 18:13:50 1998
> @@ -225,6 +225,9 @@
> #define _PAGE_4M 0x080 /* 4 MB page, Pentium+.. */
> #define _PAGE_GLOBAL 0x100 /* Global TLB entry PPro+ */
>
> +#define _PAGE_READABLE (_PAGE_PRESENT)
> +#define _PAGE_WRITABLE (_PAGE_PRESENT | _PAGE_RW)
> +
> #define _PAGE_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
> #define _KERNPG_TABLE (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
> #define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
> @@ -330,21 +333,25 @@
> * Undefined behaviour if not..
> */
> extern inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
> -extern inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_RW; }
> extern inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_USER; }
> extern inline int pte_dirty(pte_t pte) { return pte_val(pte) & _PAGE_DIRTY; }
> extern inline int pte_young(pte_t pte) { return pte_val(pte) & _PAGE_ACCESSED; }
>
> -extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~_PAGE_RW; return pte; }
> extern inline pte_t pte_rdprotect(pte_t pte) { pte_val(pte) &= ~_PAGE_USER; return pte; }
> extern inline pte_t pte_exprotect(pte_t pte) { pte_val(pte) &= ~_PAGE_USER; return pte; }
> extern inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; }
> extern inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; }
> -extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_RW; return pte; }
> extern inline pte_t pte_mkread(pte_t pte) { pte_val(pte) |= _PAGE_USER; return pte; }
> extern inline pte_t pte_mkexec(pte_t pte) { pte_val(pte) |= _PAGE_USER; return pte; }
> extern inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; }
> extern inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; }
> +
> +/*
> + * These are harder, as writability is two bits, not one..
> + */
> +extern inline int pte_write(pte_t pte) { return (pte_val(pte) & _PAGE_WRITABLE) == _PAGE_WRITABLE; }
> +extern inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= ~((pte_val(pte) & _PAGE_PRESENT) << 1); return pte; }
> +extern inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_RW; return pte; }
>
> /*
> * Conversion functions: convert a page and protection to a page entry,
>
>
>
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@vger.rutgers.edu
>


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.rutgers.edu

\
 
 \ /
  Last update: 2005-03-22 13:43    [W:0.069 / U:0.452 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site