From 16ff6f7ac92e506a05d3720e4d9fa0647bb0b5c4 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 29 Aug 2020 22:01:37 +0900 Subject: [PATCH] parisc: kprobes: Use generic kretprobe trampoline handler Use the generic kretprobe trampoline handler. Don't use framepointer verification. Signed-off-by: Masami Hiramatsu Signed-off-by: Ingo Molnar Link: https://lore.kernel.org/r/159870609708.1229682.1861714117180719169.stgit@devnote2 --- arch/parisc/kernel/kprobes.c | 76 ++---------------------------------- 1 file changed, 4 insertions(+), 72 deletions(-) diff --git a/arch/parisc/kernel/kprobes.c b/arch/parisc/kernel/kprobes.c index 77ec51818916..6d21a515eea5 100644 --- a/arch/parisc/kernel/kprobes.c +++ b/arch/parisc/kernel/kprobes.c @@ -191,80 +191,11 @@ 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; + unsigned long orig_ret_address; - 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_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); - } + orig_ret_address = __kretprobe_trampoline_handler(regs, trampoline_p.addr, NULL); instruction_pointer_set(regs, orig_ret_address); + return 1; } @@ -272,6 +203,7 @@ 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;