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-rw-r--r--Documentation/kprobes.txt1
-rw-r--r--arch/powerpc/kernel/kprobes.c25
-rw-r--r--arch/powerpc/kernel/traps.c26
3 files changed, 37 insertions, 15 deletions
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt
index 6877e7187113..a79633d702bf 100644
--- a/Documentation/kprobes.txt
+++ b/Documentation/kprobes.txt
@@ -172,6 +172,7 @@ architectures:
- ia64 (Does not support probes on instruction slot1.)
- sparc64 (Return probes not yet implemented.)
- arm
+- ppc
3. Configuring Kprobes
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c
index 74693d91731f..4ba2af125450 100644
--- a/arch/powerpc/kernel/kprobes.c
+++ b/arch/powerpc/kernel/kprobes.c
@@ -34,6 +34,13 @@
#include <asm/cacheflush.h>
#include <asm/sstep.h>
#include <asm/uaccess.h>
+#include <asm/system.h>
+
+#ifdef CONFIG_BOOKE
+#define MSR_SINGLESTEP (MSR_DE)
+#else
+#define MSR_SINGLESTEP (MSR_SE)
+#endif
DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL;
DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk);
@@ -53,7 +60,8 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p)
ret = -EINVAL;
}
- /* insn must be on a special executable page on ppc64 */
+ /* insn must be on a special executable page on ppc64. This is
+ * not explicitly required on ppc32 (right now), but it doesn't hurt */
if (!ret) {
p->ainsn.insn = get_insn_slot();
if (!p->ainsn.insn)
@@ -100,7 +108,11 @@ static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs)
* possible we'd get the single step reported for an exception handler
* like Decrementer or External Interrupt */
regs->msr &= ~MSR_EE;
- regs->msr |= MSR_SE;
+ regs->msr |= MSR_SINGLESTEP;
+#ifdef CONFIG_BOOKE
+ regs->msr &= ~MSR_CE;
+ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM);
+#endif
/*
* On powerpc we should single step on the original
@@ -163,7 +175,8 @@ static int __kprobes kprobe_handler(struct pt_regs *regs)
kprobe_opcode_t insn = *p->ainsn.insn;
if (kcb->kprobe_status == KPROBE_HIT_SS &&
is_trap(insn)) {
- regs->msr &= ~MSR_SE;
+ /* Turn off 'trace' bits */
+ regs->msr &= ~MSR_SINGLESTEP;
regs->msr |= kcb->kprobe_saved_msr;
goto no_kprobe;
}
@@ -404,10 +417,10 @@ out:
/*
* if somebody else is singlestepping across a probe point, msr
- * will have SE set, in which case, continue the remaining processing
+ * will have DE/SE set, in which case, continue the remaining processing
* of do_debug, as if this is not a probe hit.
*/
- if (regs->msr & MSR_SE)
+ if (regs->msr & MSR_SINGLESTEP)
return 0;
return 1;
@@ -430,7 +443,7 @@ int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr)
* normal page fault.
*/
regs->nip = (unsigned long)cur->addr;
- regs->msr &= ~MSR_SE;
+ regs->msr &= ~MSR_SINGLESTEP; /* Turn off 'trace' bits */
regs->msr |= kcb->kprobe_saved_msr;
if (kcb->kprobe_status == KPROBE_REENTER)
restore_previous_kprobe(kcb);
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 4b5b7ff4f78b..b463d48145a4 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -1030,21 +1030,29 @@ void SoftwareEmulation(struct pt_regs *regs)
#if defined(CONFIG_40x) || defined(CONFIG_BOOKE)
-void DebugException(struct pt_regs *regs, unsigned long debug_status)
+void __kprobes DebugException(struct pt_regs *regs, unsigned long debug_status)
{
if (debug_status & DBSR_IC) { /* instruction completion */
regs->msr &= ~MSR_DE;
+
+ /* Disable instruction completion */
+ mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
+ /* Clear the instruction completion event */
+ mtspr(SPRN_DBSR, DBSR_IC);
+
+ if (notify_die(DIE_SSTEP, "single_step", regs, 5,
+ 5, SIGTRAP) == NOTIFY_STOP) {
+ return;
+ }
+
+ if (debugger_sstep(regs))
+ return;
+
if (user_mode(regs)) {
current->thread.dbcr0 &= ~DBCR0_IC;
- } else {
- /* Disable instruction completion */
- mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) & ~DBCR0_IC);
- /* Clear the instruction completion event */
- mtspr(SPRN_DBSR, DBSR_IC);
- if (debugger_sstep(regs))
- return;
}
- _exception(SIGTRAP, regs, TRAP_TRACE, 0);
+
+ _exception(SIGTRAP, regs, TRAP_TRACE, regs->nip);
}
}
#endif /* CONFIG_4xx || CONFIG_BOOKE */