[parisc-linux] fic problem

[parisc-linux] fic problem

[FARINATI,LEANDRO (HP-Brazil,ex1)]

Hi people,

	I have an error with the use of fic asm instruction(see piece code
below). 
            I'm ask you if you have a tip do help me to solve this problem.

       buf = (char *)malloc(4096);
        if(!buf)
        {
                printf("\n malloc error!");
                return(1);
        }


        /* copy instr stream(s) to new page */
        start = (unsigned int *)&(label of an asm code);
        spot = (unsigned int *)buf;
        end = (unsigned int *)&(label of an asm code);

        while(start <= end)
        {
                *spot = *start;
                __asm__ __volatile__("fdc (%0)" :: "r" (spot) );
                __asm__ __volatile__("sync" ::);
                __asm__ __volatile__("fic (%0)" :: "r" (spot) );
(segmentation fault in this line)
                __asm__ __volatile__("sync" ::);
                spot++;
                start++;
        }

Thanks in advance,

-----------------------------------------------------------------------
              Leandro Marcondes Farinati
                    Software Developer

*   leandro.farinati@hp.com

Re: [parisc-linux] fic problem

[Matthew Wilcox]

On Fri, Dec 13, 2002 at 04:27:13AM -0800, FARINATI,LEANDRO (HP-Brazil,ex1) wrote:
>                 __asm__ __volatile__("fdc (%0)" :: "r" (spot) );
>                 __asm__ __volatile__("sync" ::);
>                 __asm__ __volatile__("fic (%0)" :: "r" (spot) );
> (segmentation fault in this line)
>                 __asm__ __volatile__("sync" ::);

don't do it like this.  do it this way:

		__asm__ __volatile__("\n\
			fdc (%0)\n\
			sync\n\
			fic (%0)\n\
			sync\n"
			: : "r" (spot)
		);

that ensures that these 4 insns really are together.  you might want to
look at the generated assembly output for this function (objdump -dr
foo.o |less) and/or recompile the kernel with PRINT_USER_TRAPS turned
on so you get a register dump so you can debug this yourself.

-- 
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