diff options
| -rw-r--r-- | Documentation/kprobes.txt | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 25 | ||||
| -rw-r--r-- | arch/powerpc/kernel/traps.c | 26 |
3 files changed, 37 insertions, 15 deletions
diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt index 6877e718711..a79633d702b 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 74693d91731..4ba2af12545 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 4b5b7ff4f78..b463d48145a 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 */ |