diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/include/asm/uprobes.h | 12 | ||||
| -rw-r--r-- | arch/x86/kernel/uprobes.c | 43 |
2 files changed, 28 insertions, 27 deletions
diff --git a/arch/x86/include/asm/uprobes.h b/arch/x86/include/asm/uprobes.h index 93bee7b93854..72caff7afbde 100644 --- a/arch/x86/include/asm/uprobes.h +++ b/arch/x86/include/asm/uprobes.h @@ -41,18 +41,20 @@ struct arch_uprobe { u8 ixol[MAX_UINSN_BYTES]; }; - u16 fixups; const struct uprobe_xol_ops *ops; union { -#ifdef CONFIG_X86_64 - unsigned long rip_rela_target_address; -#endif struct { s32 offs; u8 ilen; u8 opc1; - } branch; + } branch; + struct { +#ifdef CONFIG_X86_64 + long riprel_target; +#endif + u16 fixups; + } def; }; }; diff --git a/arch/x86/kernel/uprobes.c b/arch/x86/kernel/uprobes.c index b2bca293fc57..7824ce248f8f 100644 --- a/arch/x86/kernel/uprobes.c +++ b/arch/x86/kernel/uprobes.c @@ -251,10 +251,9 @@ static inline bool is_64bit_mm(struct mm_struct *mm) * If arch_uprobe->insn doesn't use rip-relative addressing, return * immediately. Otherwise, rewrite the instruction so that it accesses * its memory operand indirectly through a scratch register. Set - * arch_uprobe->fixups and arch_uprobe->rip_rela_target_address - * accordingly. (The contents of the scratch register will be saved - * before we single-step the modified instruction, and restored - * afterward.) + * def->fixups and def->riprel_target accordingly. (The contents of the + * scratch register will be saved before we single-step the modified + * instruction, and restored afterward). * * We do this because a rip-relative instruction can access only a * relatively small area (+/- 2 GB from the instruction), and the XOL @@ -308,18 +307,18 @@ handle_riprel_insn(struct arch_uprobe *auprobe, struct insn *insn) * is NOT the register operand, so we use %rcx (register * #1) for the scratch register. */ - auprobe->fixups = UPROBE_FIX_RIP_CX; + auprobe->def.fixups = UPROBE_FIX_RIP_CX; /* Change modrm from 00 000 101 to 00 000 001. */ *cursor = 0x1; } else { /* Use %rax (register #0) for the scratch register. */ - auprobe->fixups = UPROBE_FIX_RIP_AX; + auprobe->def.fixups = UPROBE_FIX_RIP_AX; /* Change modrm from 00 xxx 101 to 00 xxx 000 */ *cursor = (reg << 3); } /* Target address = address of next instruction + (signed) offset */ - auprobe->rip_rela_target_address = (long)insn->length + insn->displacement.value; + auprobe->def.riprel_target = (long)insn->length + insn->displacement.value; /* Displacement field is gone; slide immediate field (if any) over. */ if (insn->immediate.nbytes) { @@ -336,25 +335,25 @@ 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) { + if (auprobe->def.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) { + regs->ax += auprobe->def.riprel_target; + } else if (auprobe->def.fixups & UPROBE_FIX_RIP_CX) { autask->saved_scratch_register = regs->cx; regs->cx = current->utask->vaddr; - regs->cx += auprobe->rip_rela_target_address; + regs->cx += auprobe->def.riprel_target; } } 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)) { + if (auprobe->def.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) + if (auprobe->def.fixups & UPROBE_FIX_RIP_AX) regs->ax = autask->saved_scratch_register; else regs->cx = autask->saved_scratch_register; @@ -432,17 +431,17 @@ static int default_post_xol_op(struct arch_uprobe *auprobe, struct pt_regs *regs long correction = (long)(utask->vaddr - utask->xol_vaddr); handle_riprel_post_xol(auprobe, regs, &correction); - if (auprobe->fixups & UPROBE_FIX_IP) + if (auprobe->def.fixups & UPROBE_FIX_IP) regs->ip += correction; - if (auprobe->fixups & UPROBE_FIX_CALL) { + if (auprobe->def.fixups & UPROBE_FIX_CALL) { if (adjust_ret_addr(regs->sp, correction)) { regs->sp += sizeof_long(); return -ERESTART; } } /* popf; tell the caller to not touch TF */ - if (auprobe->fixups & UPROBE_FIX_SETF) + if (auprobe->def.fixups & UPROBE_FIX_SETF) utask->autask.saved_tf = true; return 0; @@ -646,13 +645,13 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, return ret; /* - * Figure out which fixups arch_uprobe_post_xol() will need to perform, - * and annotate arch_uprobe->fixups accordingly. To start with, ->fixups - * is either zero or it reflects rip-related fixups. + * Figure out which fixups default_post_xol_op() will need to perform, + * and annotate def->fixups accordingly. To start with, ->fixups is + * either zero or it reflects rip-related fixups. */ switch (OPCODE1(&insn)) { case 0x9d: /* popf */ - auprobe->fixups |= UPROBE_FIX_SETF; + auprobe->def.fixups |= UPROBE_FIX_SETF; break; case 0xc3: /* ret or lret -- ip is correct */ case 0xcb: @@ -680,9 +679,9 @@ int arch_uprobe_analyze_insn(struct arch_uprobe *auprobe, struct mm_struct *mm, } if (fix_ip) - auprobe->fixups |= UPROBE_FIX_IP; + auprobe->def.fixups |= UPROBE_FIX_IP; if (fix_call) - auprobe->fixups |= UPROBE_FIX_CALL; + auprobe->def.fixups |= UPROBE_FIX_CALL; auprobe->ops = &default_xol_ops; return 0; |