forked from luck/tmp_suning_uos_patched
[S390] kprobes: single step cleanup
The saved interrupt mask and the saved control registers are only relevant while single stepping is set up. A secondary kprobe while kprobe single stepping is active may not occur. That makes is safe to remove the save and restore of kprobe_saved_imask / kprobe_save_ctl from save_previous_kprobe and restore_previous_kprobe. Move all single step related code to two functions, enable_singlestep and disable_singlestep. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
parent
35f2aaa79a
commit
fc0a1fea6b
|
@ -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 */
|
||||
|
|
|
@ -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 {
|
||||
|
|
Loading…
Reference in New Issue
Block a user