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[S390] kprobes: Fix the return address of multiple kretprobes

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Analog to git commit 737480a0d5
fix the return address of subsequent kretprobes when multiple
kretprobes are set on the same function.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Martin Schwidefsky 2010-11-10 10:05:58 +01:00 committed by Martin Schwidefsky
parent adb4583981
commit 89480801a1
1 changed files with 26 additions and 3 deletions
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29
arch/s390/kernel/kprobes.c
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@ -349,6 +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);
@ -371,10 +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) {
@ -386,7 +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();