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Diffstat (limited to 'arch/s390/kernel/kprobes.c')
-rw-r--r--arch/s390/kernel/kprobes.c70
1 files changed, 53 insertions, 17 deletions
diff --git a/arch/s390/kernel/kprobes.c b/arch/s390/kernel/kprobes.c
index d60fc4398516..2564793ec2b6 100644
--- a/arch/s390/kernel/kprobes.c
+++ b/arch/s390/kernel/kprobes.c
@@ -30,6 +30,7 @@
#include <asm/sections.h>
#include <linux/module.h>
#include <linux/slab.h>
+#include <linux/hardirq.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -212,7 +213,7 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
/* Set the PER control regs, turns on single step for this address */
__ctl_load(kprobe_per_regs, 9, 11);
regs->psw.mask |= PSW_MASK_PER;
- regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT | PSW_MASK_MCHECK);
+ regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
}
static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb)
@@ -239,7 +240,7 @@ static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs,
__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 | PSW_MASK_MCHECK);
+ (PSW_MASK_PER | PSW_MASK_IO | PSW_MASK_EXT);
/* Save the control regs that govern PER */
__ctl_store(kcb->kprobe_saved_ctl, 9, 11);
}
@@ -316,8 +317,6 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
return 1;
ss_probe:
- if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
- local_irq_disable();
prepare_singlestep(p, regs);
kcb->kprobe_status = KPROBE_HIT_SS;
return 1;
@@ -350,6 +349,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
struct hlist_node *node, *tmp;
unsigned long flags, orig_ret_address = 0;
unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
+ kprobe_opcode_t *correct_ret_addr = NULL;
INIT_HLIST_HEAD(&empty_rp);
kretprobe_hash_lock(current, &head, &flags);
@@ -372,10 +372,32 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
/* another task is sharing our hash bucket */
continue;
- if (ri->rp && ri->rp->handler)
- ri->rp->handler(ri, regs);
+ orig_ret_address = (unsigned long)ri->ret_addr;
+
+ if (orig_ret_address != trampoline_address)
+ /*
+ * This is the real return address. Any other
+ * instances associated with this task are for
+ * other calls deeper on the call stack
+ */
+ break;
+ }
+
+ kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
+ correct_ret_addr = ri->ret_addr;
+ hlist_for_each_entry_safe(ri, node, tmp, head, hlist) {
+ if (ri->task != current)
+ /* another task is sharing our hash bucket */
+ continue;
orig_ret_address = (unsigned long)ri->ret_addr;
+
+ if (ri->rp && ri->rp->handler) {
+ ri->ret_addr = correct_ret_addr;
+ ri->rp->handler(ri, regs);
+ }
+
recycle_rp_inst(ri, &empty_rp);
if (orig_ret_address != trampoline_address) {
@@ -387,7 +409,7 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p,
break;
}
}
- kretprobe_assert(ri, orig_ret_address, trampoline_address);
+
regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
reset_current_kprobe();
@@ -465,8 +487,6 @@ static int __kprobes post_kprobe_handler(struct pt_regs *regs)
goto out;
}
reset_current_kprobe();
- if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
- local_irq_enable();
out:
preempt_enable_no_resched();
@@ -482,7 +502,7 @@ out:
return 1;
}
-int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+static int __kprobes kprobe_trap_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
@@ -508,8 +528,6 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
restore_previous_kprobe(kcb);
else {
reset_current_kprobe();
- if (regs->psw.mask & (PSW_MASK_PER | PSW_MASK_IO))
- local_irq_enable();
}
preempt_enable_no_resched();
break;
@@ -553,6 +571,18 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
return 0;
}
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+{
+ int ret;
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_disable();
+ ret = kprobe_trap_handler(regs, trapnr);
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+ return ret;
+}
+
/*
* Wrapper routine to for handling exceptions.
*/
@@ -560,8 +590,12 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
unsigned long val, void *data)
{
struct die_args *args = (struct die_args *)data;
+ struct pt_regs *regs = args->regs;
int ret = NOTIFY_DONE;
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_disable();
+
switch (val) {
case DIE_BPT:
if (kprobe_handler(args->regs))
@@ -572,16 +606,17 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self,
ret = NOTIFY_STOP;
break;
case DIE_TRAP:
- /* kprobe_running() needs smp_processor_id() */
- preempt_disable();
- if (kprobe_running() &&
- kprobe_fault_handler(args->regs, args->trapnr))
+ if (!preemptible() && kprobe_running() &&
+ kprobe_trap_handler(args->regs, args->trapnr))
ret = NOTIFY_STOP;
- preempt_enable();
break;
default:
break;
}
+
+ if (regs->psw.mask & (PSW_MASK_IO | PSW_MASK_EXT))
+ local_irq_restore(regs->psw.mask & ~PSW_MASK_PER);
+
return ret;
}
@@ -595,6 +630,7 @@ int __kprobes setjmp_pre_handler(struct kprobe *p, struct pt_regs *regs)
/* setup return addr to the jprobe handler routine */
regs->psw.addr = (unsigned long)(jp->entry) | PSW_ADDR_AMODE;
+ regs->psw.mask &= ~(PSW_MASK_IO | PSW_MASK_EXT);
/* r14 is the function return address */
kcb->jprobe_saved_r14 = (unsigned long)regs->gprs[14];
generated by cgit v1.2.3 (git 2.0.4) at 2024-11-03 23:23:22 +0000