On Thu, 2013-10-31 at 13:38 -0500, Tom wrote:
> From: Tom Musta <tommu...@gmail.com>
>
> This patch modifies the unaligned access routines of the sstep.c
> module so that it properly reverses the bytes of storage operands
> in the little endian kernel kernel.
Do that patch differ from v1 ? (I already merged v1)
Cheers,
Ben.
> Signed-off-by: Tom Musta <tommu...@gmail.com>
> ---
> arch/powerpc/lib/sstep.c | 45 +++++++++++++++++++++++++++++++++++++++++++++
> 1 files changed, 45 insertions(+), 0 deletions(-)
>
> diff --git a/arch/powerpc/lib/sstep.c b/arch/powerpc/lib/sstep.c
> index 7bfaa9d..c8743e1 100644
> --- a/arch/powerpc/lib/sstep.c
> +++ b/arch/powerpc/lib/sstep.c
> @@ -212,11 +212,19 @@ static int __kprobes read_mem_unaligned(unsigned long
> *dest, unsigned long ea,
> {
> int err;
> unsigned long x, b, c;
> +#ifdef __LITTLE_ENDIAN__
> + int len = nb; /* save a copy of the length for byte reversal */
> +#endif
>
> /* unaligned, do this in pieces */
> x = 0;
> for (; nb > 0; nb -= c) {
> +#ifdef __LITTLE_ENDIAN__
> + c = 1;
> +#endif
> +#ifdef __BIG_ENDIAN__
> c = max_align(ea);
> +#endif
> if (c > nb)
> c = max_align(nb);
> err = read_mem_aligned(&b, ea, c);
> @@ -225,7 +233,24 @@ static int __kprobes read_mem_unaligned(unsigned long
> *dest, unsigned long ea,
> x = (x << (8 * c)) + b;
> ea += c;
> }
> +#ifdef __LITTLE_ENDIAN__
> + switch (len) {
> + case 2:
> + *dest = byterev_2(x);
> + break;
> + case 4:
> + *dest = byterev_4(x);
> + break;
> +#ifdef __powerpc64__
> + case 8:
> + *dest = byterev_8(x);
> + break;
> +#endif
> + }
> +#endif
> +#ifdef __BIG_ENDIAN__
> *dest = x;
> +#endif
> return 0;
> }
>
> @@ -273,9 +298,29 @@ static int __kprobes write_mem_unaligned(unsigned long
> val, unsigned long ea,
> int err;
> unsigned long c;
>
> +#ifdef __LITTLE_ENDIAN__
> + switch (nb) {
> + case 2:
> + val = byterev_2(val);
> + break;
> + case 4:
> + val = byterev_4(val);
> + break;
> +#ifdef __powerpc64__
> + case 8:
> + val = byterev_8(val);
> + break;
> +#endif
> + }
> +#endif
> /* unaligned or little-endian, do this in pieces */
> for (; nb > 0; nb -= c) {
> +#ifdef __LITTLE_ENDIAN__
> + c = 1;
> +#endif
> +#ifdef __BIG_ENDIAN__
> c = max_align(ea);
> +#endif
> if (c > nb)
> c = max_align(nb);
> err = write_mem_aligned(val >> (nb - c) * 8, ea, c);
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