Re: [PATCH v9 3.2 1/9] uprobes: Install and remove breakpoints.

[Masami Hiramatsu]

(2012/01/10 20:48), Srikar Dronamraju wrote:
> +static void handle_riprel_insn(struct mm_struct *mm, struct uprobe *uprobe,
> +							struct insn *insn)
> +{
> +	u8 *cursor;
> +	u8 reg;
> +
> +	if (mm->context.ia32_compat)
> +		return;
> +
> +	uprobe->arch_info.rip_rela_target_address = 0x0;
> +	if (!insn_rip_relative(insn))
> +		return;
> +
> +	/*
> +	 * Point cursor at the modrm byte.  The next 4 bytes are the
> +	 * displacement.  Beyond the displacement, for some instructions,
> +	 * is the immediate operand.
> +	 */
> +	cursor = uprobe->insn + insn->prefixes.nbytes
> +			+ insn->rex_prefix.nbytes + insn->opcode.nbytes;

FYI, insn.h already provide a macro for this purpose.
You can write this as below;

	cursor = uprobe->insn + insn_offset_modrm(insn);

Thank you,

-- 
Masami HIRAMATSU
Software Platform Research Dept. Linux Technology Center
Hitachi, Ltd., Yokohama Research Laboratory
E-mail: masami.hiramatsu.pt@xxxxxxxxxxx
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/