diff options
Diffstat (limited to 'arch/parisc/kernel/kprobes.c')
| -rw-r--r-- | arch/parisc/kernel/kprobes.c | 104 |
1 files changed, 21 insertions, 83 deletions
diff --git a/arch/parisc/kernel/kprobes.c b/arch/parisc/kernel/kprobes.c index 77ec51818916..6e0b86652f30 100644 --- a/arch/parisc/kernel/kprobes.c +++ b/arch/parisc/kernel/kprobes.c @@ -5,6 +5,7 @@ * PA-RISC kprobes implementation * * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org> + * Copyright (c) 2022 Helge Deller <deller@gmx.de> */ #include <linux/types.h> @@ -25,9 +26,14 @@ int __kprobes arch_prepare_kprobe(struct kprobe *p) if (!p->ainsn.insn) return -ENOMEM; - memcpy(p->ainsn.insn, p->addr, - MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); + /* + * Set up new instructions. Second break instruction will + * trigger call of parisc_kprobe_ss_handler(). + */ p->opcode = *p->addr; + p->ainsn.insn[0] = p->opcode; + p->ainsn.insn[1] = PARISC_KPROBES_BREAK_INSN2; + flush_insn_slot(p); return 0; } @@ -73,9 +79,7 @@ static void __kprobes setup_singlestep(struct kprobe *p, { kcb->iaoq[0] = regs->iaoq[0]; kcb->iaoq[1] = regs->iaoq[1]; - regs->iaoq[0] = (unsigned long)p->ainsn.insn; - mtctl(0, 0); - regs->gr[0] |= PSW_R; + instruction_pointer_set(regs, (unsigned long)p->ainsn.insn); } int __kprobes parisc_kprobe_break_handler(struct pt_regs *regs) @@ -148,7 +152,7 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs) /* for absolute branch instructions we can copy iaoq_b. for relative * branch instructions we need to calculate the new address based on the * difference between iaoq_f and iaoq_b. We cannot use iaoq_b without - * modificationt because it's based on our ainsn.insn address. + * modifications because it's based on our ainsn.insn address. */ if (p->post_handler) @@ -165,9 +169,8 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs) regs->iaoq[0] = kcb->iaoq[1]; break; default: - regs->iaoq[1] = kcb->iaoq[0]; - regs->iaoq[1] += (regs->iaoq[1] - regs->iaoq[0]) + 4; regs->iaoq[0] = kcb->iaoq[1]; + regs->iaoq[1] = regs->iaoq[0] + 4; break; } kcb->kprobe_status = KPROBE_HIT_SSDONE; @@ -175,7 +178,7 @@ int __kprobes parisc_kprobe_ss_handler(struct pt_regs *regs) return 1; } -static inline void kretprobe_trampoline(void) +void __kretprobe_trampoline(void) { asm volatile("nop"); asm volatile("nop"); @@ -191,87 +194,22 @@ static struct kprobe trampoline_p = { static int __kprobes 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)trampoline_p.addr; - kprobe_opcode_t *correct_ret_addr = NULL; - - 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 multiple functions in the call path have - * a return probe installed on them, and/or more than one 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; - - orig_ret_address = (unsigned long)ri->ret_addr; - - 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_trampoline_handler(regs, NULL); - kretprobe_assert(ri, orig_ret_address, trampoline_address); - - correct_ret_addr = ri->ret_addr; - hlist_for_each_entry_safe(ri, tmp, head, hlist) { - if (ri->task != current) - /* another task is sharing our hash bucket */ - continue; - - orig_ret_address = (unsigned long)ri->ret_addr; - if (ri->rp && ri->rp->handler) { - __this_cpu_write(current_kprobe, &ri->rp->kp); - get_kprobe_ctlblk()->kprobe_status = KPROBE_HIT_ACTIVE; - ri->ret_addr = correct_ret_addr; - ri->rp->handler(ri, regs); - __this_cpu_write(current_kprobe, NULL); - } - - 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_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } - instruction_pointer_set(regs, orig_ret_address); return 1; } +void arch_kretprobe_fixup_return(struct pt_regs *regs, + kprobe_opcode_t *correct_ret_addr) +{ + regs->gr[2] = (unsigned long)correct_ret_addr; +} + void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *)regs->gr[2]; + ri->fp = NULL; /* Replace the return addr with trampoline addr. */ regs->gr[2] = (unsigned long)trampoline_p.addr; @@ -285,6 +223,6 @@ int __kprobes arch_trampoline_kprobe(struct kprobe *p) int __init arch_init_kprobes(void) { trampoline_p.addr = (kprobe_opcode_t *) - dereference_function_descriptor(kretprobe_trampoline); + dereference_function_descriptor(__kretprobe_trampoline); return register_kprobe(&trampoline_p); } |