From: Oleg Nesterov Date: Mon, 31 Mar 2014 15:24:14 +0000 (+0200) Subject: uprobes/x86: Conditionalize the usage of handle_riprel_insn() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=e55848a4f8ee52465771983e144f0c3337776eda;p=linux-beck.git uprobes/x86: Conditionalize the usage of handle_riprel_insn() arch_uprobe_analyze_insn() calls handle_riprel_insn() at the start, but only "0xff" and "default" cases need the UPROBE_FIX_RIP_ logic. Move the callsite into "default" case and change the "0xff" case to fall-through. We are going to add the various hooks to handle the rip-relative jmp/call instructions (and more), we need this change to enforce the fact that the new code can not conflict with is_riprel_insn() logic which, after this change, can only be used by default_xol_ops. Note: arch_uprobe_abort_xol() still calls handle_riprel_post_xol() directly. This is fine unless another _xol_ops we may add later will need to reuse "UPROBE_FIX_RIP_AX|UPROBE_FIX_RIP_CX" bits in ->fixup. In this case we can add uprobe_xol_ops->abort() hook, which (perhaps) we will need anyway in the long term. Signed-off-by: Oleg Nesterov Reviewed-by: Jim Keniston Reviewed-by: Masami Hiramatsu --- diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 13ad8a38c2d9..08cdb82815fe 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -482,8 +482,6 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, * and annotate arch_uprobe->fixups accordingly. To start with, ->fixups * is either zero or it reflects rip-related fixups. */ - handle_riprel_insn(auprobe, &insn); - switch (OPCODE1(&insn)) { case 0x9d: /* popf */ auprobe->fixups |= UPROBE_FIX_SETF; @@ -512,9 +510,9 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, case 4: case 5: /* jmp or ljmp, indirect */ fix_ip = false; } - break; + /* fall through */ default: - break; + handle_riprel_insn(auprobe, &insn); } if (fix_ip)