From: Masami Hiramatsu mhiramat@kernel.org
[ Upstream commit e792ff804f49720ce003b3e4c618b5d996256a18 ]
Use the generic kretprobe trampoline handler. Don't use framepointer verification.
Signed-off-by: Masami Hiramatsu mhiramat@kernel.org Signed-off-by: Ingo Molnar mingo@kernel.org Link: https://lore.kernel.org/r/159870606883.1229682.12331813108378725668.stgit@de... Signed-off-by: Sasha Levin sashal@kernel.org --- arch/ia64/kernel/kprobes.c | 77 +------------------------------------- 1 file changed, 2 insertions(+), 75 deletions(-)
diff --git a/arch/ia64/kernel/kprobes.c b/arch/ia64/kernel/kprobes.c index b8356edbde659..b3dc39050c1ad 100644 --- a/arch/ia64/kernel/kprobes.c +++ b/arch/ia64/kernel/kprobes.c @@ -396,83 +396,9 @@ static void kretprobe_trampoline(void) { }
-/* - * At this point the target function has been tricked into - * returning into our trampoline. Lookup the associated instance - * and then: - * - call the handler function - * - cleanup by marking the instance as unused - * - long jump back to the original return address - */ 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 = - ((struct fnptr *)kretprobe_trampoline)->ip; - - 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; - - 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; - } - - regs->cr_iip = orig_ret_address; - - 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); - - kretprobe_hash_unlock(current, &flags); - - hlist_for_each_entry_safe(ri, tmp, &empty_rp, hlist) { - hlist_del(&ri->hlist); - kfree(ri); - } + regs->cr_iip = __kretprobe_trampoline_handler(regs, kretprobe_trampoline, NULL); /* * By returning a non-zero value, we are telling * kprobe_handler() that we don't want the post_handler @@ -485,6 +411,7 @@ void __kprobes arch_prepare_kretprobe(struct kretprobe_instance *ri, struct pt_regs *regs) { ri->ret_addr = (kprobe_opcode_t *)regs->b0; + ri->fp = NULL;
/* Replace the return addr with trampoline addr */ regs->b0 = ((struct fnptr *)kretprobe_trampoline)->ip;