From d032ae8921ea792c1e6b2abb44022b2403f651f6 Mon Sep 17 00:00:00 2001 From: Joel Fernandes Date: Tue, 15 Nov 2016 12:31:20 -0800 Subject: [PATCH] ftrace: Provide API to use global filtering for ftrace ops Currently the global_ops filtering hash is not available to outside users registering for function tracing. Provide an API for those users to be able to choose global filtering. This is in preparation for pstore's ftrace feature to be able to use the global filters. Suggested-by: Steven Rostedt Cc: Anton Vorontsov Cc: Colin Cross Cc: Kees Cook Cc: Tony Luck Signed-off-by: Joel Fernandes Acked-by: Steven Rostedt Signed-off-by: Kees Cook --- include/linux/ftrace.h | 2 ++ kernel/trace/ftrace.c | 17 +++++++++++++++++ 2 files changed, 19 insertions(+) diff --git a/include/linux/ftrace.h b/include/linux/ftrace.h index b3d34d3e0e7e..d4a884db16a3 100644 --- a/include/linux/ftrace.h +++ b/include/linux/ftrace.h @@ -398,6 +398,7 @@ int ftrace_set_notrace(struct ftrace_ops *ops, unsigned char *buf, void ftrace_set_global_filter(unsigned char *buf, int len, int reset); void ftrace_set_global_notrace(unsigned char *buf, int len, int reset); void ftrace_free_filter(struct ftrace_ops *ops); +void ftrace_ops_set_global_filter(struct ftrace_ops *ops); int register_ftrace_command(struct ftrace_func_command *cmd); int unregister_ftrace_command(struct ftrace_func_command *cmd); @@ -645,6 +646,7 @@ static inline unsigned long ftrace_location(unsigned long ip) #define ftrace_set_filter(ops, buf, len, reset) ({ -ENODEV; }) #define ftrace_set_notrace(ops, buf, len, reset) ({ -ENODEV; }) #define ftrace_free_filter(ops) do { } while (0) +#define ftrace_ops_set_global_filter(ops) do { } while (0) static inline ssize_t ftrace_filter_write(struct file *file, const char __user *ubuf, size_t cnt, loff_t *ppos) { return -ENODEV; } diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 2050a7652a86..89d46e1c9302 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -4239,6 +4239,23 @@ int ftrace_set_filter_ip(struct ftrace_ops *ops, unsigned long ip, } EXPORT_SYMBOL_GPL(ftrace_set_filter_ip); +/** + * ftrace_ops_set_global_filter - setup ops to use global filters + * @ops - the ops which will use the global filters + * + * ftrace users who need global function trace filtering should call this. + * It can set the global filter only if ops were not initialized before. + */ +void ftrace_ops_set_global_filter(struct ftrace_ops *ops) +{ + if (ops->flags & FTRACE_OPS_FL_INITIALIZED) + return; + + ftrace_ops_init(ops); + ops->func_hash = &global_ops.local_hash; +} +EXPORT_SYMBOL_GPL(ftrace_ops_set_global_filter); + static int ftrace_set_regex(struct ftrace_ops *ops, unsigned char *buf, int len, int reset, int enable) -- GitLab