diff options
Diffstat (limited to 'arch/powerpc/kernel/kprobes.c')
| -rw-r--r-- | arch/powerpc/kernel/kprobes.c | 47 |
1 files changed, 32 insertions, 15 deletions
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 81efb605113e..6f96f65ebfe8 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -23,6 +23,7 @@ #include <asm/cacheflush.h> #include <asm/sstep.h> #include <asm/sections.h> +#include <asm/inst.h> #include <linux/uaccess.h> DEFINE_PER_CPU(struct kprobe *, current_kprobe) = NULL; @@ -105,7 +106,9 @@ kprobe_opcode_t *kprobe_lookup_name(const char *name, unsigned int offset) int arch_prepare_kprobe(struct kprobe *p) { int ret = 0; - kprobe_opcode_t insn = *p->addr; + struct kprobe *prev; + struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->addr); + struct ppc_inst prefix = ppc_inst_read((struct ppc_inst *)(p->addr - 1)); if ((unsigned long)p->addr & 0x03) { printk("Attempt to register kprobe at an unaligned address\n"); @@ -113,6 +116,17 @@ int arch_prepare_kprobe(struct kprobe *p) } else if (IS_MTMSRD(insn) || IS_RFID(insn) || IS_RFI(insn)) { printk("Cannot register a kprobe on rfi/rfid or mtmsr[d]\n"); ret = -EINVAL; + } else if (ppc_inst_prefixed(prefix)) { + printk("Cannot register a kprobe on the second word of prefixed instruction\n"); + ret = -EINVAL; + } + preempt_disable(); + prev = get_kprobe(p->addr - 1); + preempt_enable_no_resched(); + if (prev && + ppc_inst_prefixed(ppc_inst_read((struct ppc_inst *)prev->ainsn.insn))) { + printk("Cannot register a kprobe on the second word of prefixed instruction\n"); + ret = -EINVAL; } /* insn must be on a special executable page on ppc64. This is @@ -124,11 +138,8 @@ int arch_prepare_kprobe(struct kprobe *p) } if (!ret) { - memcpy(p->ainsn.insn, p->addr, - MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); - p->opcode = *p->addr; - flush_icache_range((unsigned long)p->ainsn.insn, - (unsigned long)p->ainsn.insn + sizeof(kprobe_opcode_t)); + patch_instruction((struct ppc_inst *)p->ainsn.insn, insn); + p->opcode = ppc_inst_val(insn); } p->ainsn.boostable = 0; @@ -138,13 +149,13 @@ NOKPROBE_SYMBOL(arch_prepare_kprobe); void arch_arm_kprobe(struct kprobe *p) { - patch_instruction(p->addr, BREAKPOINT_INSTRUCTION); + patch_instruction((struct ppc_inst *)p->addr, ppc_inst(BREAKPOINT_INSTRUCTION)); } NOKPROBE_SYMBOL(arch_arm_kprobe); void arch_disarm_kprobe(struct kprobe *p) { - patch_instruction(p->addr, p->opcode); + patch_instruction((struct ppc_inst *)p->addr, ppc_inst(p->opcode)); } NOKPROBE_SYMBOL(arch_disarm_kprobe); @@ -216,7 +227,7 @@ NOKPROBE_SYMBOL(arch_prepare_kretprobe); static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) { int ret; - unsigned int insn = *p->ainsn.insn; + struct ppc_inst insn = ppc_inst_read((struct ppc_inst *)p->ainsn.insn); /* regs->nip is also adjusted if emulate_step returns 1 */ ret = emulate_step(regs, insn); @@ -233,7 +244,7 @@ static int try_to_emulate(struct kprobe *p, struct pt_regs *regs) * So, we should never get here... but, its still * good to catch them, just in case... */ - printk("Can't step on instruction %x\n", insn); + printk("Can't step on instruction %x\n", ppc_inst_val(insn)); BUG(); } else { /* @@ -276,14 +287,18 @@ int kprobe_handler(struct pt_regs *regs) p = get_kprobe(addr); if (!p) { - if (*addr != BREAKPOINT_INSTRUCTION) { + unsigned int instr; + + if (probe_kernel_address(addr, instr)) + goto no_kprobe; + + if (instr != BREAKPOINT_INSTRUCTION) { /* * PowerPC has multiple variants of the "trap" * instruction. If the current instruction is a * trap variant, it could belong to someone else */ - kprobe_opcode_t cur_insn = *addr; - if (is_trap(cur_insn)) + if (is_trap(instr)) goto no_kprobe; /* * The breakpoint instruction was removed right @@ -464,14 +479,16 @@ NOKPROBE_SYMBOL(trampoline_probe_handler); */ int kprobe_post_handler(struct pt_regs *regs) { + int len; struct kprobe *cur = kprobe_running(); struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); if (!cur || user_mode(regs)) return 0; + len = ppc_inst_len(ppc_inst_read((struct ppc_inst *)cur->ainsn.insn)); /* make sure we got here for instruction we have a kprobe on */ - if (((unsigned long)cur->ainsn.insn + 4) != regs->nip) + if (((unsigned long)cur->ainsn.insn + len) != regs->nip) return 0; if ((kcb->kprobe_status != KPROBE_REENTER) && cur->post_handler) { @@ -480,7 +497,7 @@ int kprobe_post_handler(struct pt_regs *regs) } /* Adjust nip to after the single-stepped instruction */ - regs->nip = (unsigned long)cur->addr + 4; + regs->nip = (unsigned long)cur->addr + len; regs->msr |= kcb->kprobe_saved_msr; /*Restore back the original saved kprobes variables and continue. */ |