diff options
Diffstat (limited to 'arch/mips/kernel/kprobes.c')
-rw-r--r-- | arch/mips/kernel/kprobes.c | 123 |
1 files changed, 41 insertions, 82 deletions
diff --git a/arch/mips/kernel/kprobes.c b/arch/mips/kernel/kprobes.c index 6cfae2411c04..dc39f5b3fb83 100644 --- a/arch/mips/kernel/kprobes.c +++ b/arch/mips/kernel/kprobes.c @@ -11,6 +11,8 @@ * Copyright (C) IBM Corporation, 2002, 2004 */ +#define pr_fmt(fmt) "kprobes: " fmt + #include <linux/kprobes.h> #include <linux/preempt.h> #include <linux/uaccess.h> @@ -42,19 +44,20 @@ static const union mips_instruction breakpoint2_insn = { DEFINE_PER_CPU(struct kprobe *, current_kprobe); DEFINE_PER_CPU(struct kprobe_ctlblk, kprobe_ctlblk); -static int __kprobes insn_has_delayslot(union mips_instruction insn) +static int insn_has_delayslot(union mips_instruction insn) { return __insn_has_delay_slot(insn); } +NOKPROBE_SYMBOL(insn_has_delayslot); /* * insn_has_ll_or_sc function checks whether instruction is ll or sc * one; putting breakpoint on top of atomic ll/sc pair is bad idea; * so we need to prevent it and refuse kprobes insertion for such * instructions; cannot do much about breakpoint in the middle of - * ll/sc pair; it is upto user to avoid those places + * ll/sc pair; it is up to user to avoid those places */ -static int __kprobes insn_has_ll_or_sc(union mips_instruction insn) +static int insn_has_ll_or_sc(union mips_instruction insn) { int ret = 0; @@ -70,8 +73,9 @@ static int __kprobes insn_has_ll_or_sc(union mips_instruction insn) } return ret; } +NOKPROBE_SYMBOL(insn_has_ll_or_sc); -int __kprobes arch_prepare_kprobe(struct kprobe *p) +int arch_prepare_kprobe(struct kprobe *p) { union mips_instruction insn; union mips_instruction prev_insn; @@ -80,15 +84,14 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) insn = p->addr[0]; if (insn_has_ll_or_sc(insn)) { - pr_notice("Kprobes for ll and sc instructions are not" - "supported\n"); + pr_notice("Kprobes for ll and sc instructions are not supported\n"); ret = -EINVAL; goto out; } - if ((probe_kernel_read(&prev_insn, p->addr - 1, - sizeof(mips_instruction)) == 0) && - insn_has_delayslot(prev_insn)) { + if (copy_from_kernel_nofault(&prev_insn, p->addr - 1, + sizeof(mips_instruction)) == 0 && + insn_has_delayslot(prev_insn)) { pr_notice("Kprobes for branch delayslot are not supported\n"); ret = -EINVAL; goto out; @@ -131,26 +134,30 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) out: return ret; } +NOKPROBE_SYMBOL(arch_prepare_kprobe); -void __kprobes arch_arm_kprobe(struct kprobe *p) +void arch_arm_kprobe(struct kprobe *p) { *p->addr = breakpoint_insn; flush_insn_slot(p); } +NOKPROBE_SYMBOL(arch_arm_kprobe); -void __kprobes arch_disarm_kprobe(struct kprobe *p) +void arch_disarm_kprobe(struct kprobe *p) { *p->addr = p->opcode; flush_insn_slot(p); } +NOKPROBE_SYMBOL(arch_disarm_kprobe); -void __kprobes arch_remove_kprobe(struct kprobe *p) +void arch_remove_kprobe(struct kprobe *p) { if (p->ainsn.insn) { free_insn_slot(p->ainsn.insn, 0); p->ainsn.insn = NULL; } } +NOKPROBE_SYMBOL(arch_remove_kprobe); static void save_previous_kprobe(struct kprobe_ctlblk *kcb) { @@ -219,7 +226,7 @@ static int evaluate_branch_instruction(struct kprobe *p, struct pt_regs *regs, return 0; unaligned: - pr_notice("%s: unaligned epc - sending SIGBUS.\n", current->comm); + pr_notice("Failed to emulate branch instruction because of unaligned epc - sending SIGBUS to %s.\n", current->comm); force_sig(SIGBUS); return -EFAULT; @@ -238,10 +245,8 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, regs->cp0_epc = (unsigned long)p->addr; else if (insn_has_delayslot(p->opcode)) { ret = evaluate_branch_instruction(p, regs, kcb); - if (ret < 0) { - pr_notice("Kprobes: Error in evaluating branch\n"); + if (ret < 0) return; - } } regs->cp0_epc = (unsigned long)&p->ainsn.insn[0]; } @@ -258,7 +263,7 @@ static void prepare_singlestep(struct kprobe *p, struct pt_regs *regs, * breakpoint trap. In case of branch instructions, the target * epc to be restored. */ -static void __kprobes resume_execution(struct kprobe *p, +static void resume_execution(struct kprobe *p, struct pt_regs *regs, struct kprobe_ctlblk *kcb) { @@ -269,8 +274,9 @@ static void __kprobes resume_execution(struct kprobe *p, regs->cp0_epc = orig_epc + 4; } } +NOKPROBE_SYMBOL(resume_execution); -static int __kprobes kprobe_handler(struct pt_regs *regs) +static int kprobe_handler(struct pt_regs *regs) { struct kprobe *p; int ret = 0; @@ -368,6 +374,7 @@ no_kprobe: return ret; } +NOKPROBE_SYMBOL(kprobe_handler); static inline int post_kprobe_handler(struct pt_regs *regs) { @@ -403,9 +410,6 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - if (cur->fault_handler && cur->fault_handler(cur, regs, trapnr)) - return 1; - if (kcb->kprobe_status & KPROBE_HIT_SS) { resume_execution(cur, regs, kcb); regs->cp0_status |= kcb->kprobe_old_SR; @@ -419,7 +423,7 @@ int kprobe_fault_handler(struct pt_regs *regs, int trapnr) /* * Wrapper routine for handling exceptions. */ -int __kprobes kprobe_exceptions_notify(struct notifier_block *self, +int kprobe_exceptions_notify(struct notifier_block *self, unsigned long val, void *data) { @@ -450,6 +454,7 @@ int __kprobes kprobe_exceptions_notify(struct notifier_block *self, } return ret; } +NOKPROBE_SYMBOL(kprobe_exceptions_notify); /* * Function return probe trampoline: @@ -464,81 +469,33 @@ static void __used kretprobe_trampoline_holder(void) /* Keep the assembler from reordering and placing JR here. */ ".set noreorder\n\t" "nop\n\t" - ".global kretprobe_trampoline\n" - "kretprobe_trampoline:\n\t" + ".global __kretprobe_trampoline\n" + "__kretprobe_trampoline:\n\t" "nop\n\t" ".set pop" : : : "memory"); } -void kretprobe_trampoline(void); +void __kretprobe_trampoline(void); -void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, +void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *) regs->regs[31]; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ - regs->regs[31] = (unsigned long)kretprobe_trampoline; + regs->regs[31] = (unsigned long)__kretprobe_trampoline; } +NOKPROBE_SYMBOL(arch_prepare_kretprobe); /* * Called when the probe at kretprobe trampoline is hit */ -static int __kprobes trampoline_probe_handler(struct kprobe *p, +static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) { - struct kretprobe_instance *ri = NULL; - struct hlist_head *head, empty_rp; - struct hlist_node *tmp; - unsigned long flags, orig_ret_address = 0; - unsigned long trampoline_address = (unsigned long)kretprobe_trampoline; - - INIT_HLIST_HEAD(&empty_rp); - kretprobe_hash_lock(current, &head, &flags); - - /* - * It is possible to have multiple instances associated with a given - * task either because an multiple functions in the call path - * have a return probe installed on them, and/or more than one return - * return probe was registered for a target function. - * - * We can handle this because: - * - instances are always inserted at the head of the list - * - when multiple return probes are registered for the same - * function, the first instance's ret_addr will point to the - * real return address, and all the rest will point to - * kretprobe_trampoline - */ - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* 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; - recycle_rp_inst(ri, &empty_rp); - - 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); - instruction_pointer(regs) = orig_ret_address; - - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } + instruction_pointer(regs) = __kretprobe_trampoline_handler(regs, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler @@ -546,17 +503,19 @@ static int __kprobes trampoline_probe_handler(struct kprobe *p, */ return 1; } +NOKPROBE_SYMBOL(trampoline_probe_handler); -int __kprobes arch_trampoline_kprobe(struct kprobe *p) +int arch_trampoline_kprobe(struct kprobe *p) { - if (p->addr == (kprobe_opcode_t *)kretprobe_trampoline) + if (p->addr == (kprobe_opcode_t *)__kretprobe_trampoline) return 1; return 0; } +NOKPROBE_SYMBOL(arch_trampoline_kprobe); static struct kprobe trampoline_p = { - .addr = (kprobe_opcode_t *)kretprobe_trampoline, + .addr = (kprobe_opcode_t *)__kretprobe_trampoline, .pre_handler = trampoline_probe_handler }; |