From 59495740f79524bebe4ecb8097cf206f86587b25 Mon Sep 17 00:00:00 2001 From: Florent Revest Date: Tue, 21 Mar 2023 15:04:18 +0100 Subject: ftrace: Let unregister_ftrace_direct_multi() call ftrace_free_filter() A common pattern when using the ftrace_direct_multi API is to unregister the ops and also immediately free its filter. We've noticed it's very easy for users to miss calling ftrace_free_filter(). This adds a "free_filters" argument to unregister_ftrace_direct_multi() to both remind the user they should free filters and also to make their life easier. Link: https://lkml.kernel.org/r/20230321140424.345218-2-revest@chromium.org Suggested-by: Steven Rostedt Signed-off-by: Florent Revest Acked-by: Mark Rutland Acked-by: Jiri Olsa Signed-off-by: Steven Rostedt (Google) --- kernel/bpf/trampoline.c | 2 +- kernel/trace/ftrace.c | 6 +++++- 2 files changed, 6 insertions(+), 2 deletions(-) (limited to 'kernel') diff --git a/kernel/bpf/trampoline.c b/kernel/bpf/trampoline.c index d0ed7d6f5eec..88bc23f1e10a 100644 --- a/kernel/bpf/trampoline.c +++ b/kernel/bpf/trampoline.c @@ -198,7 +198,7 @@ static int unregister_fentry(struct bpf_trampoline *tr, void *old_addr) int ret; if (tr->func.ftrace_managed) - ret = unregister_ftrace_direct_multi(tr->fops, (long)old_addr); + ret = unregister_ftrace_direct_multi(tr->fops, (long)old_addr, false); else ret = bpf_arch_text_poke(ip, BPF_MOD_CALL, old_addr, NULL); diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 0feea145bb29..98434196c6a1 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -5805,7 +5805,8 @@ EXPORT_SYMBOL_GPL(register_ftrace_direct_multi); * 0 on success * -EINVAL - The @ops object was not properly registered. */ -int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) +int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr, + bool free_filters) { struct ftrace_hash *hash = ops->func_hash->filter_hash; int err; @@ -5823,6 +5824,9 @@ int unregister_ftrace_direct_multi(struct ftrace_ops *ops, unsigned long addr) /* cleanup for possible another register call */ ops->func = NULL; ops->trampoline = 0; + + if (free_filters) + ftrace_free_filter(ops); return err; } EXPORT_SYMBOL_GPL(unregister_ftrace_direct_multi); -- cgit v1.2.3