That's true, lets do it right, thanks.
/Carsten
Jun Sun wrote:
> Just to be nit-picking, the end point should be (addr + size - 1).
>
> Jun
>
> Carsten Langgaard wrote:
>
> > The __access_ok macro in include/asm-mips64/uaccess.h need to be changed
> > in order to work correctly, it's a copy from the 32-bit kernel.
> > It's not good enough to simply check for the "sign bit" of the address.
> > The area between USEG (XUSEG) and KSEG0 will in 64-bit addressing mode
> > generate an address error, if
> > accessed. The size of the area depend on the number of virtual
> > addressing bits, implemented in the CPU.
> >
> > I have tried to come up with a patch, please see below. Any thought ?
> > I also changed the macro in arch/mips64/kernel/unaligned.c
> >
> > /Carsten
> >
> >
> > Index: include/asm-mips64//uaccess.h
> > ===================================================================
> > RCS file:
> > /home/repository/sw/linux-2.4.18/include/asm-mips64/uaccess.h,v
> > retrieving revision 1.1.1.1
> > diff -u -r1.1.1.1 uaccess.h
> > --- include/asm-mips64//uaccess.h 4 Mar 2002 11:13:26 -0000
> > 1.1.1.1
> > +++ include/asm-mips64//uaccess.h 17 Jun 2002 11:35:32 -0000
> > @@ -12,6 +12,8 @@
> > #include <linux/errno.h>
> > #include <linux/sched.h>
> >
> > +#include <asm/addrspace.h>
> > +
> > #define STR(x) __STR(x)
> > #define __STR(x) #x
> >
> > @@ -40,16 +42,23 @@
> > * than tests.
> > *
> > * Address valid if:
> > - * - "addr" doesn't have any high-bits set
> > - * - AND "size" doesn't have any high-bits set
> > - * - AND "addr+size" doesn't have any high-bits set
> > - * - OR we are in kernel mode.
> > + * - In user mode and "addr" and "addr+size" in USEG (or XUSEG).
> > + * - OR we are in kernel mode and "addr" and "addr+size" isn't in the
> > + * area between USEG (XUSEG) and KSEG0.
> > */
> > #define
> > __ua_size(size) \
> > (__builtin_constant_p(size) && (signed long) (size) > 0 ? 0 :
> > (size))
> >
> > -#define __access_ok(addr,size,mask)
> > \
> > - (((signed long)((mask)&(addr | (addr + size) |
> > __ua_size(size)))) >= 0)
> > +static inline int
> > +__access_ok(unsigned long addr, unsigned long size, long mask)
> > +{
> > + if (((mask) && ((addr | (addr+size)) >= KUSIZE)) ||
> > + (((addr | (addr+size)) < K0BASE) &&
> > + ((addr | (addr+size)) >= KUSIZE)))
> > + return 0;
> > + else
> > + return 1;
> > +}
> >
> > #define __access_mask ((long)(get_fs().seg))
> >
> >
> > Index: arch/mips64/kernel/unaligned.c
> > ===================================================================
> > RCS file:
> > /home/repository/sw/linux-2.4.18/arch/mips64/kernel/unaligned.c,v
> > retrieving revision 1.2
> > diff -u -r1.2 unaligned.c
> > --- arch/mips64/kernel/unaligned.c 23 May 2002 11:11:45 -0000
> > 1.2
> > +++ arch/mips64/kernel/unaligned.c 17 Jun 2002 11:51:30 -0000
> > @@ -89,11 +89,14 @@
> > #define __STR(x) #x
> >
> > /*
> > - * User code may only access USEG; kernel code may access the
> > - * entire address space.
> > + * User code may only access USEG;
> > + * Kernel code may access the entire address space, except the area
> > between
> > + * USEG (XUSEG) and KSEG0.
> > */
> > -#define check_axs(pc,a,s) \
> > - if ((long)(~(pc) & ((a) | ((a)+(s)))) < 0) \
> > +#define check_axs(pc,a,s)
> > \
> > + if (((pc < KUSIZE) && (((a) | ((a)+(s))) >= KUSIZE))
> > || \
> > + ((((a) | ((a)+(s))) < K0BASE) &&
> > \
> > + (((a) | ((a)+(s))) >= KUSIZE)))
> > \
> > goto sigbus;
> >
> >
> >
> > --
> > _ _ ____ ___ Carsten Langgaard Mailto:carstenl@mips.com
> > |\ /|||___)(___ MIPS Denmark Direct: +45 4486 5527
> > | \/ ||| ____) Lautrupvang 4B Switch: +45 4486 5555
> > TECHNOLOGIES 2750 Ballerup Fax...: +45 4486 5556
> > Denmark http://www.mips.com
> >
> >
> >
> >
--
_ _ ____ ___ Carsten Langgaard Mailto:carstenl@mips.com
|\ /|||___)(___ MIPS Denmark Direct: +45 4486 5527
| \/ ||| ____) Lautrupvang 4B Switch: +45 4486 5555
TECHNOLOGIES 2750 Ballerup Fax...: +45 4486 5556
Denmark http://www.mips.com
