#include <linux/ptrace.h>
#include <linux/preempt.h>
#include <linux/stop_machine.h>
+#include <linux/kdebug.h>
#include <asm/cacheflush.h>
-#include <asm/kdebug.h>
#include <asm/sections.h>
#include <asm/uaccess.h>
#include <linux/module.h>
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
+struct kretprobe_blackpoint kretprobe_blacklist[] = {{NULL, NULL}};
+
int __kprobes arch_prepare_kprobe(struct kprobe *p)
{
/* Make sure the probe isn't going on a difficult instruction */
if (is_prohibited_opcode((kprobe_opcode_t *) p->addr))
return -EINVAL;
- if ((unsigned long)p->addr & 0x01) {
- printk("Attempt to register kprobe at an unaligned address\n");
+ if ((unsigned long)p->addr & 0x01)
return -EINVAL;
- }
/* Use the get_insn_slot() facility for correctness */
if (!(p->ainsn.insn = get_insn_slot()))
ainsn->reg = (*ainsn->insn & 0xf0) >> 4;
/* save the instruction length (pop 5-5) in bytes */
- switch (*(__u8 *) (ainsn->insn) >> 4) {
+ switch (*(__u8 *) (ainsn->insn) >> 6) {
case 0:
ainsn->ilen = 2;
break;
static int __kprobes swap_instruction(void *aref)
{
struct ins_replace_args *args = aref;
+ u32 *addr;
+ u32 instr;
int err = -EFAULT;
+ /*
+ * Text segment is read-only, hence we use stura to bypass dynamic
+ * address translation to exchange the instruction. Since stura
+ * always operates on four bytes, but we only want to exchange two
+ * bytes do some calculations to get things right. In addition we
+ * shall not cross any page boundaries (vmalloc area!) when writing
+ * the new instruction.
+ */
+ addr = (u32 *)((unsigned long)args->ptr & -4UL);
+ if ((unsigned long)args->ptr & 2)
+ instr = ((*addr) & 0xffff0000) | args->new;
+ else
+ instr = ((*addr) & 0x0000ffff) | args->new << 16;
+
asm volatile(
- "0: mvc 0(2,%2),0(%3)\n"
- "1: la %0,0\n"
+ " lra %1,0(%1)\n"
+ "0: stura %2,%1\n"
+ "1: la %0,0\n"
"2:\n"
EX_TABLE(0b,2b)
- : "+d" (err), "=m" (*args->ptr)
- : "a" (args->ptr), "a" (&args->new), "m" (args->new));
+ : "+d" (err)
+ : "a" (addr), "d" (instr)
+ : "memory", "cc");
+
return err;
}
args.new = BREAKPOINT_INSTRUCTION;
kcb->kprobe_status = KPROBE_SWAP_INST;
- stop_machine_run(swap_instruction, &args, NR_CPUS);
+ stop_machine(swap_instruction, &args, NULL);
kcb->kprobe_status = status;
}
args.new = p->opcode;
kcb->kprobe_status = KPROBE_SWAP_INST;
- stop_machine_run(swap_instruction, &args, NR_CPUS);
+ stop_machine(swap_instruction, &args, NULL);
kcb->kprobe_status = status;
}
void __kprobes arch_remove_kprobe(struct kprobe *p)
{
- mutex_lock(&kprobe_mutex);
- free_insn_slot(p->ainsn.insn, 0);
- mutex_unlock(&kprobe_mutex);
+ if (p->ainsn.insn) {
+ free_insn_slot(p->ainsn.insn, 0);
+ p->ainsn.insn = NULL;
+ }
}
static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
__ctl_store(kcb->kprobe_saved_ctl, 9, 11);
}
-/* Called with kretprobe_lock held */
-void __kprobes arch_prepare_kretprobe(struct kretprobe *rp,
+void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri,
struct pt_regs *regs)
{
- struct kretprobe_instance *ri;
-
- if ((ri = get_free_rp_inst(rp)) != NULL) {
- ri->rp = rp;
- ri->task = current;
- ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
-
- /* Replace the return addr with trampoline addr */
- regs->gprs[14] = (unsigned long)&kretprobe_trampoline;
+ ri->ret_addr = (kprobe_opcode_t *) regs->gprs[14];
- add_rp_inst(ri);
- } else {
- rp->nmissed++;
- }
+ /* Replace the return addr with trampoline addr */
+ regs->gprs[14] = (unsigned long)&kretprobe_trampoline;
}
static int __kprobes kprobe_handler(struct pt_regs *regs)
}
p = get_kprobe(addr);
- if (!p) {
- if (*addr != BREAKPOINT_INSTRUCTION) {
- /*
- * The breakpoint instruction was removed right
- * after we hit it. Another cpu has removed
- * either a probepoint or a debugger breakpoint
- * at this address. In either case, no further
- * handling of this interrupt is appropriate.
- *
- */
- ret = 1;
- }
- /* Not one of ours: let kernel handle it */
+ if (!p)
+ /*
+ * No kprobe at this address. The fault has not been
+ * caused by a kprobe breakpoint. The race of breakpoint
+ * vs. kprobe remove does not exist because on s390 we
+ * use stop_machine to arm/disarm the breakpoints.
+ */
goto no_kprobe;
- }
kcb->kprobe_status = KPROBE_HIT_ACTIVE;
set_current_kprobe(p, regs, kcb);
* - When the probed function returns, this probe
* causes the handlers to fire
*/
-void __kprobes kretprobe_trampoline_holder(void)
+static void __used kretprobe_trampoline_holder(void)
{
asm volatile(".global kretprobe_trampoline\n"
"kretprobe_trampoline: bcr 0,0\n");
unsigned long trampoline_address = (unsigned long)&kretprobe_trampoline;
INIT_HLIST_HEAD(&empty_rp);
- spin_lock_irqsave(&kretprobe_lock, flags);
- head = kretprobe_inst_table_head(current);
+ kretprobe_hash_lock(current, &head, &flags);
/*
* It is possible to have multiple instances associated with a given
break;
}
}
- BUG_ON(!orig_ret_address || (orig_ret_address == trampoline_address));
+ kretprobe_assert(ri, orig_ret_address, trampoline_address);
regs->psw.addr = orig_ret_address | PSW_ADDR_AMODE;
reset_current_kprobe();
- spin_unlock_irqrestore(&kretprobe_lock, flags);
+ kretprobe_hash_unlock(current, &flags);
preempt_enable_no_resched();
hlist_for_each_entry_safe(ri, node, tmp, &empty_rp, hlist) {
return 1;
}
-static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
+int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
{
struct kprobe *cur = kprobe_running();
struct kprobe_ctlblk *kcb = get_kprobe_ctlblk();
ret = NOTIFY_STOP;
break;
case DIE_TRAP:
- case DIE_PAGE_FAULT:
/* kprobe_running() needs smp_processor_id() */
preempt_disable();
if (kprobe_running() &&
{
return register_kprobe(&trampoline_p);
}
+
+int __kprobes arch_trampoline_kprobe(struct kprobe *p)
+{
+ if (p->addr == (kprobe_opcode_t *) & kretprobe_trampoline)
+ return 1;
+ return 0;
+}