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linux/kernel/trace/ftrace_internal.h
Steven Rostedt (Google) 4267fda4af function_graph: Make fgraph_update_pid_func() a stub for !DYNAMIC_FTRACE
When CONFIG_DYNAMIC_FTRACE is not set, the function
fgraph_update_pid_func() doesn't do anything. Currently, most of its logic
is within a "#ifdef CONFIG_DYNAMIC_FTRACE" block, but its variables were
declared outside that, and when DYNAMIC_FTRACE is not set, it produces
unused variable warnings.

Instead, just place it (and the helper function fgraph_pid_func()) within
the #ifdef block and have the header file use a empty stub function for
when DYNAMIC_FTRACE is not defined.

Link: https://lore.kernel.org/linux-trace-kernel/20240607094833.6a787d73@rorschach.local.home

Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202406071806.BRjaC5FF-lkp@intel.com/
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
2024-06-10 18:08:23 -04:00

69 lines
2.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_KERNEL_FTRACE_INTERNAL_H
#define _LINUX_KERNEL_FTRACE_INTERNAL_H
int __register_ftrace_function(struct ftrace_ops *ops);
int __unregister_ftrace_function(struct ftrace_ops *ops);
#ifdef CONFIG_FUNCTION_TRACER
extern struct mutex ftrace_lock;
extern struct ftrace_ops global_ops;
#ifdef CONFIG_DYNAMIC_FTRACE
int ftrace_startup(struct ftrace_ops *ops, int command);
int ftrace_shutdown(struct ftrace_ops *ops, int command);
int ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs);
int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command);
int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command);
#else /* !CONFIG_DYNAMIC_FTRACE */
/* Keep as macros so we do not need to define the commands */
# define ftrace_startup(ops, command) \
({ \
int ___ret = __register_ftrace_function(ops); \
if (!___ret) \
(ops)->flags |= FTRACE_OPS_FL_ENABLED; \
___ret; \
})
# define ftrace_shutdown(ops, command) \
({ \
int ___ret = __unregister_ftrace_function(ops); \
if (!___ret) \
(ops)->flags &= ~FTRACE_OPS_FL_ENABLED; \
___ret; \
})
static inline int
ftrace_ops_test(struct ftrace_ops *ops, unsigned long ip, void *regs)
{
return 1;
}
static inline int ftrace_startup_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command)
{
return -EINVAL;
}
static inline int ftrace_shutdown_subops(struct ftrace_ops *ops, struct ftrace_ops *subops, int command)
{
return -EINVAL;
}
#endif /* CONFIG_DYNAMIC_FTRACE */
#ifdef CONFIG_FUNCTION_GRAPH_TRACER
extern int ftrace_graph_active;
# ifdef CONFIG_DYNAMIC_FTRACE
extern void fgraph_update_pid_func(void);
# else
static inline void fgraph_update_pid_func(void) {}
# endif
#else /* !CONFIG_FUNCTION_GRAPH_TRACER */
# define ftrace_graph_active 0
static inline void fgraph_update_pid_func(void) {}
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
#else /* !CONFIG_FUNCTION_TRACER */
#endif /* CONFIG_FUNCTION_TRACER */
#endif