From b6c5a58dd89e683e66b52a57a6f022fda79a0aab Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Sat, 29 Aug 2020 22:01:48 +0900 Subject: powerpc: 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/159870610825.1229682.2090635992093223399.stgit@devnote2 --- arch/powerpc/kernel/kprobes.c | 53 +++---------------------------------------- 1 file changed, 3 insertions(+), 50 deletions(-) diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index 6ab9b4d037c3..01ab2163659e 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -218,6 +218,7 @@ bool arch_kprobe_on_func_entry(unsigned long offset) void arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *)regs->link; + ri->fp = NULL; /* Replace the return addr with trampoline addr */ regs->link = (unsigned long)kretprobe_trampoline; @@ -396,50 +397,9 @@ asm(".global kretprobe_trampoline\n" */ 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); + unsigned long orig_ret_address; + orig_ret_address = __kretprobe_trampoline_handler(regs, &kretprobe_trampoline, NULL); /* * We get here through one of two paths: * 1. by taking a trap -> kprobe_handler() -> here @@ -458,13 +418,6 @@ static int trampoline_probe_handler(struct kprobe *p, struct pt_regs *regs) regs->nip = orig_ret_address - 4; regs->link = 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 0; } NOKPROBE_SYMBOL(trampoline_probe_handler); -- cgit v1.2.3