X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=arch%2Fsparc64%2Fkernel%2Fkprobes.c;h=2e1c824c1cc9512356460ea3a09f2fd74c11dfe2;hp=96bd09b098f431876c87778594983f0bf514f85d;hb=69cd291c6bbc6647fe3783257c5a2e076e808f71;hpb=8006fdd6dc387abaa4b683bda4868c879fd76070 diff --git a/arch/sparc64/kernel/kprobes.c b/arch/sparc64/kernel/kprobes.c index 96bd09b098f4..2e1c824c1cc9 100644 --- a/arch/sparc64/kernel/kprobes.c +++ b/arch/sparc64/kernel/kprobes.c @@ -6,9 +6,11 @@ #include #include #include +#include #include #include #include +#include /* We do not have hardware single-stepping on sparc64. * So we implement software single-stepping with breakpoint @@ -42,15 +44,11 @@ DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); int __kprobes arch_prepare_kprobe(struct kprobe *p) -{ - return 0; -} - -void __kprobes arch_copy_kprobe(struct kprobe *p) { p->ainsn.insn[0] = *p->addr; p->ainsn.insn[1] = BREAKPOINT_INSTRUCTION_2; p->opcode = *p->addr; + return 0; } void __kprobes arch_arm_kprobe(struct kprobe *p) @@ -65,11 +63,7 @@ void __kprobes arch_disarm_kprobe(struct kprobe *p) flushi(p->addr); } -void __kprobes arch_remove_kprobe(struct kprobe *p) -{ -} - -static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) +static void __kprobes save_previous_kprobe(struct kprobe_ctlblk *kcb) { kcb->prev_kprobe.kp = kprobe_running(); kcb->prev_kprobe.status = kcb->kprobe_status; @@ -77,7 +71,7 @@ static inline void save_previous_kprobe(struct kprobe_ctlblk *kcb) kcb->prev_kprobe.orig_tstate_pil = kcb->kprobe_orig_tstate_pil; } -static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb) +static void __kprobes restore_previous_kprobe(struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = kcb->prev_kprobe.kp; kcb->kprobe_status = kcb->prev_kprobe.status; @@ -85,7 +79,7 @@ static inline void restore_previous_kprobe(struct kprobe_ctlblk *kcb) kcb->kprobe_orig_tstate_pil = kcb->prev_kprobe.orig_tstate_pil; } -static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs, +static void __kprobes set_current_kprobe(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { __get_cpu_var(current_kprobe) = p; @@ -93,7 +87,7 @@ static inline void set_current_kprobe(struct kprobe *p, struct pt_regs *regs, kcb->kprobe_orig_tstate_pil = (regs->tstate & TSTATE_PIL); } -static inline void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, +static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { regs->tstate |= TSTATE_PIL; @@ -138,11 +132,19 @@ static int __kprobes kprobe_handler(struct pt_regs *regs) */ save_previous_kprobe(kcb); set_current_kprobe(p, regs, kcb); - p->nmissed++; + kprobes_inc_nmissed_count(p); kcb->kprobe_status = KPROBE_REENTER; prepare_singlestep(p, regs, kcb); return 1; } else { + if (*(u32 *)addr != BREAKPOINT_INSTRUCTION) { + /* The breakpoint instruction was removed by + * another cpu right after we hit, no further + * handling of this interrupt is appropriate + */ + ret = 1; + goto no_kprobe; + } p = __get_cpu_var(current_kprobe); if (p->break_handler && p->break_handler(p, regs)) goto ss_probe; @@ -271,7 +273,7 @@ static void __kprobes resume_execution(struct kprobe *p, kcb->kprobe_orig_tstate_pil); } -static inline int post_kprobe_handler(struct pt_regs *regs) +static int __kprobes post_kprobe_handler(struct pt_regs *regs) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); @@ -298,20 +300,72 @@ out: return 1; } -static inline int kprobe_fault_handler(struct pt_regs *regs, int trapnr) +static int __kprobes kprobe_fault_handler(struct pt_regs *regs, int trapnr) { struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); + const struct exception_table_entry *entry; + + switch(kcb->kprobe_status) { + case KPROBE_HIT_SS: + case KPROBE_REENTER: + /* + * We are here because the instruction being single + * stepped caused a page fault. We reset the current + * kprobe and the tpc points back to the probe address + * and allow the page fault handler to continue as a + * normal page fault. + */ + regs->tpc = (unsigned long)cur->addr; + regs->tnpc = kcb->kprobe_orig_tnpc; + regs->tstate = ((regs->tstate & ~TSTATE_PIL) | + kcb->kprobe_orig_tstate_pil); + if (kcb->kprobe_status == KPROBE_REENTER) + restore_previous_kprobe(kcb); + else + reset_current_kprobe(); + preempt_enable_no_resched(); + break; + case KPROBE_HIT_ACTIVE: + case KPROBE_HIT_SSDONE: + /* + * We increment the nmissed count for accounting, + * we can also use npre/npostfault count for accouting + * these specific fault cases. + */ + kprobes_inc_nmissed_count(cur); + + /* + * We come here because instructions in the pre/post + * handler caused the page_fault, this could happen + * if handler tries to access user space by + * copy_from_user(), get_user() etc. Let the + * user-specified handler try to fix it first. + */ + if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) + return 1; - if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) - return 1; + /* + * In case the user-specified fault handler returned + * zero, try to fix up. + */ - if (kcb->kprobe_status & KPROBE_HIT_SS) { - resume_execution(cur, regs, kcb); + entry = search_exception_tables(regs->tpc); + if (entry) { + regs->tpc = entry->fixup; + regs->tnpc = regs->tpc + 4; + return 1; + } - reset_current_kprobe(); - preempt_enable_no_resched(); + /* + * fixup_exception() could not handle it, + * Let do_page_fault() fix it. + */ + break; + default: + break; } + return 0; } @@ -324,6 +378,9 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, struct die_args *args = (struct die_args *)data; int ret = NOTIFY_DONE; + if (args->regs && user_mode(args->regs)) + return ret; + switch (val) { case DIE_DEBUG: if (kprobe_handler(args->regs))