diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 118 |
1 files changed, 53 insertions, 65 deletions
diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index 963c121c0307..c52c30fa7871 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -313,6 +313,48 @@ handle_riprel_insn(struct arch_uprobe *auprobe, struct insn *insn) } } +/* + * If we're emulating a rip-relative instruction, save the contents + * of the scratch register and store the target address in that register. + */ +static void +pre_xol_rip_insn(struct arch_uprobe *auprobe, struct pt_regs *regs, + struct arch_uprobe_task *autask) +{ + if (auprobe->fixups & UPROBE_FIX_RIP_AX) { + autask->saved_scratch_register = regs->ax; + regs->ax = current->utask->vaddr; + regs->ax += auprobe->rip_rela_target_address; + } else if (auprobe->fixups & UPROBE_FIX_RIP_CX) { + autask->saved_scratch_register = regs->cx; + regs->cx = current->utask->vaddr; + regs->cx += auprobe->rip_rela_target_address; + } +} + +static void +handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long *correction) +{ + if (auprobe->fixups & (UPROBE_FIX_RIP_AX | UPROBE_FIX_RIP_CX)) { + struct arch_uprobe_task *autask; + + autask = ¤t->utask->autask; + if (auprobe->fixups & UPROBE_FIX_RIP_AX) + regs->ax = autask->saved_scratch_register; + else + regs->cx = autask->saved_scratch_register; + + /* + * The original instruction includes a displacement, and so + * is 4 bytes longer than what we've just single-stepped. + * Caller may need to apply other fixups to handle stuff + * like "jmpq *...(%rip)" and "callq *...(%rip)". + */ + if (correction) + *correction += 4; + } +} + static int validate_insn_64bits(struct arch_uprobe *auprobe, struct insn *insn) { insn_init(insn, auprobe->insn, true); @@ -339,9 +381,19 @@ static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm, return validate_insn_64bits(auprobe, insn); } #else /* 32-bit: */ +/* + * No RIP-relative addressing on 32-bit + */ static void handle_riprel_insn(struct arch_uprobe *auprobe, struct insn *insn) { - /* No RIP-relative addressing on 32-bit */ +} +static void pre_xol_rip_insn(struct arch_uprobe *auprobe, struct pt_regs *regs, + struct arch_uprobe_task *autask) +{ +} +static void handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, + long *correction) +{ } static int validate_insn_bits(struct arch_uprobe *auprobe, struct mm_struct *mm, struct insn *insn) @@ -415,34 +467,6 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, return 0; } -#ifdef CONFIG_X86_64 -/* - * If we're emulating a rip-relative instruction, save the contents - * of the scratch register and store the target address in that register. - */ -static void -pre_xol_rip_insn(struct arch_uprobe *auprobe, struct pt_regs *regs, - struct arch_uprobe_task *autask) -{ - if (auprobe->fixups & UPROBE_FIX_RIP_AX) { - autask->saved_scratch_register = regs->ax; - regs->ax = current->utask->vaddr; - regs->ax += auprobe->rip_rela_target_address; - } else if (auprobe->fixups & UPROBE_FIX_RIP_CX) { - autask->saved_scratch_register = regs->cx; - regs->cx = current->utask->vaddr; - regs->cx += auprobe->rip_rela_target_address; - } -} -#else -static void -pre_xol_rip_insn(struct arch_uprobe *auprobe, struct pt_regs *regs, - struct arch_uprobe_task *autask) -{ - /* No RIP-relative addressing on 32-bit */ -} -#endif - /* * arch_uprobe_pre_xol - prepare to execute out of line. * @auprobe: the probepoint information. @@ -492,42 +516,6 @@ static int adjust_ret_addr(unsigned long sp, long correction) return 0; } -#ifdef CONFIG_X86_64 -static bool is_riprel_insn(struct arch_uprobe *auprobe) -{ - return ((auprobe->fixups & (UPROBE_FIX_RIP_AX | UPROBE_FIX_RIP_CX)) != 0); -} - -static void -handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long *correction) -{ - if (is_riprel_insn(auprobe)) { - struct arch_uprobe_task *autask; - - autask = ¤t->utask->autask; - if (auprobe->fixups & UPROBE_FIX_RIP_AX) - regs->ax = autask->saved_scratch_register; - else - regs->cx = autask->saved_scratch_register; - - /* - * The original instruction includes a displacement, and so - * is 4 bytes longer than what we've just single-stepped. - * Fall through to handle stuff like "jmpq *...(%rip)" and - * "callq *...(%rip)". - */ - if (correction) - *correction += 4; - } -} -#else -static void -handle_riprel_post_xol(struct arch_uprobe *auprobe, struct pt_regs *regs, long *correction) -{ - /* No RIP-relative addressing on 32-bit */ -} -#endif - /* * If xol insn itself traps and generates a signal(Say, * SIGILL/SIGSEGV/etc), then detect the case where a singlestepped |