From 0cf0e2fe91fade050bfda2a7240550ba6106b760 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 29 Aug 2020 22:02:15 +0900 Subject: [PATCH] sh: 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/159870613547.1229682.15519965962108261812.stgit@devnote2 --- arch/sh/kernel/kprobes.c | 58 +++------------------------------------- 1 file changed, 3 insertions(+), 55 deletions(-) diff --git a/arch/sh/kernel/kprobes.c b/arch/sh/kernel/kprobes.c index 318296f48f1a..756100b01e84 100644 --- a/arch/sh/kernel/kprobes.c +++ b/arch/sh/kernel/kprobes.c @@ -204,6 +204,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *) regs->pr; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ regs->pr = (unsigned long)kretprobe_trampoline; @@ -302,62 +303,9 @@ static void __used kretprobe_trampoline_holder(void) */ 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)&kretprobe_trampoline; + regs->pc = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, 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 an multiple functions in the call path - * have a return probe installed on them, and/or more then 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) { - __this_cpu_write(current_kprobe, &ri->rp->kp); - ri->rp->handler(ri, regs); - __this_cpu_write(current_kprobe, NULL); - } - - 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); - - regs->pc = orig_ret_address; - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } - - return orig_ret_address; + return 1; } static int __kprobes post_kprobe_handler(struct pt_regs *regs)