diff options
| -rw-r--r-- | arch/s390/include/asm/kprobes.h | 3 | ||||
| -rw-r--r-- | arch/s390/kernel/kprobes.c | 77 |
2 files changed, 36 insertions, 44 deletions
diff --git a/arch/s390/include/asm/kprobes.h b/arch/s390/include/asm/kprobes.h index 330f68caffe..15d0dec8dbb 100644 --- a/arch/s390/include/asm/kprobes.h +++ b/arch/s390/include/asm/kprobes.h @@ -72,9 +72,6 @@ struct ins_replace_args { struct prev_kprobe { struct kprobe *kp; unsigned long status; - unsigned long saved_psw; - unsigned long kprobe_saved_imask; - unsigned long kprobe_saved_ctl[3]; }; /* per-cpu kprobe control block */ diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c index b8e51759b6e..91c611f84ff 100644 --- a/arch/s390/kernel/kprobes.c +++ b/arch/s390/kernel/kprobes.c @@ -198,51 +198,58 @@ void __kprobes arch_remove_kprobe(struct kprobe *p) } } -static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) +static void __kprobes enable_singlestep(struct kprobe_ctlblk *kcb, + struct pt_regs *regs, + unsigned long ip) { per_cr_bits kprobe_per_regs[1]; - memset(kprobe_per_regs, 0, sizeof(per_cr_bits)); - regs->psw.addr = (unsigned long)p->ainsn.insn | PSW_ADDR_AMODE; - /* Set up the per control reg info, will pass to lctl */ + memset(kprobe_per_regs, 0, sizeof(per_cr_bits)); kprobe_per_regs[0].em_instruction_fetch = 1; - kprobe_per_regs[0].starting_addr = (unsigned long)p->ainsn.insn; - kprobe_per_regs[0].ending_addr = (unsigned long)p->ainsn.insn + 1; + kprobe_per_regs[0].starting_addr = ip; + kprobe_per_regs[0].ending_addr = ip; - /* Set the PER control regs, turns on single step for this address */ + /* Save control regs and psw mask */ + __ctl_store(kcb->kprobe_saved_ctl, 9, 11); + kcb->kprobe_saved_imask = regs->psw.mask & + (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT); + + /* Set PER control regs, turns on single step for the given address */ __ctl_load(kprobe_per_regs, 9, 11); regs->psw.mask |= PSW_MASK_PER; regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT); + regs->psw.addr = ip | PSW_ADDR_AMODE; } +static void __kprobes disable_singlestep(struct kprobe_ctlblk *kcb, + struct pt_regs *regs, + unsigned long ip) +{ + /* Restore control regs and psw mask, set new psw address */ + __ctl_load(kcb->kprobe_saved_ctl, 9, 11); + regs->psw.mask &= ~PSW_MASK_PER; + regs->psw.mask |= kcb->kprobe_saved_imask; + regs->psw.addr = ip | PSW_ADDR_AMODE; +} + + static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) { kcb->prev_kprobe.kp = kprobe_running(); kcb->prev_kprobe.status = kcb->kprobe_status; - kcb->prev_kprobe.kprobe_saved_imask = kcb->kprobe_saved_imask; - memcpy(kcb->prev_kprobe.kprobe_saved_ctl, kcb->kprobe_saved_ctl, - sizeof(kcb->kprobe_saved_ctl)); } static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; kcb->kprobe_status = kcb->prev_kprobe.status; - kcb->kprobe_saved_imask = kcb->prev_kprobe.kprobe_saved_imask; - memcpy(kcb->kprobe_saved_ctl, kcb->prev_kprobe.kprobe_saved_ctl, - sizeof(kcb->kprobe_saved_ctl)); } static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = p; - /* Save the interrupt and per flags */ - kcb->kprobe_saved_imask = regs->psw.mask & - (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT); - /* Save the control regs that govern PER */ - __ctl_store(kcb->kprobe_saved_ctl, 9, 11); } void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, @@ -282,7 +289,8 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) save_previous_kprobe(kcb); set_current_kprobe(p, regs, kcb); kprobes_inc_nmissed_count(p); - prepare_singlestep(p, regs); + enable_singlestep(kcb, regs, + (unsigned long) p->ainsn.insn); kcb->kprobe_status = KPROBE_REENTER; return 1; } else { @@ -311,7 +319,7 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) return 1; ss_probe: - prepare_singlestep(p, regs); + enable_singlestep(kcb, regs, (unsigned long) p->ainsn.insn); kcb->kprobe_status = KPROBE_HIT_SS; return 1; @@ -433,31 +441,20 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, static void __kprobes resume_execution(struct kprobe *p, struct pt_regs *regs) { struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - - regs->psw.addr &= PSW_ADDR_INSN; + unsigned long ip = regs->psw.addr & PSW_ADDR_INSN; if (p->ainsn.fixup & FIXUP_PSW_NORMAL) - regs->psw.addr = (unsigned long)p->addr + - ((unsigned long)regs->psw.addr - - (unsigned long)p->ainsn.insn); + ip += (unsigned long) p->addr - (unsigned long) p->ainsn.insn; if (p->ainsn.fixup & FIXUP_BRANCH_NOT_TAKEN) - if ((unsigned long)regs->psw.addr - - (unsigned long)p->ainsn.insn == p->ainsn.ilen) - regs->psw.addr = (unsigned long)p->addr + p->ainsn.ilen; + if (ip - (unsigned long) p->ainsn.insn == p->ainsn.ilen) + ip = (unsigned long) p->addr + p->ainsn.ilen; if (p->ainsn.fixup & FIXUP_RETURN_REGISTER) - regs->gprs[p->ainsn.reg] = ((unsigned long)p->addr + - (regs->gprs[p->ainsn.reg] - - (unsigned long)p->ainsn.insn)) - | PSW_ADDR_AMODE; + regs->gprs[p->ainsn.reg] += (unsigned long) p->addr - + (unsigned long) p->ainsn.insn; - regs->psw.addr |= PSW_ADDR_AMODE; - /* turn off PER mode */ - regs->psw.mask &= ~PSW_MASK_PER; - /* Restore the original per control regs */ - __ctl_load(kcb->kprobe_saved_ctl, 9, 11); - regs->psw.mask |= kcb->kprobe_saved_imask; + disable_singlestep(kcb, regs, ip); } static int __kprobes post_kprobe_handler(struct pt_regs *regs) @@ -515,9 +512,7 @@ static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr) * and allow the page fault handler to continue as a * normal page fault. */ - regs->psw.addr = (unsigned long)cur->addr | PSW_ADDR_AMODE; - regs->psw.mask &= ~PSW_MASK_PER; - regs->psw.mask |= kcb->kprobe_saved_imask; + disable_singlestep(kcb, regs, (unsigned long) cur->addr); if (kcb->kprobe_status == KPROBE_REENTER) restore_previous_kprobe(kcb); else { |