mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-09-12 13:55:32 +00:00
5b0ab78998
Add exit_handler to fprobe. fprobe + rethook allows us to hook the kernel function return. The rethook will be enabled only if the fprobe::exit_handler is set. Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org> Tested-by: Steven Rostedt (Google) <rostedt@goodmis.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/164735290790.1084943.10601965782208052202.stgit@devnote2
93 lines
2.5 KiB
C
93 lines
2.5 KiB
C
/* SPDX-License-Identifier: GPL-2.0 */
|
|
/* Simple ftrace probe wrapper */
|
|
#ifndef _LINUX_FPROBE_H
|
|
#define _LINUX_FPROBE_H
|
|
|
|
#include <linux/compiler.h>
|
|
#include <linux/ftrace.h>
|
|
#include <linux/rethook.h>
|
|
|
|
/**
|
|
* struct fprobe - ftrace based probe.
|
|
* @ops: The ftrace_ops.
|
|
* @nmissed: The counter for missing events.
|
|
* @flags: The status flag.
|
|
* @rethook: The rethook data structure. (internal data)
|
|
* @entry_handler: The callback function for function entry.
|
|
* @exit_handler: The callback function for function exit.
|
|
*/
|
|
struct fprobe {
|
|
#ifdef CONFIG_FUNCTION_TRACER
|
|
/*
|
|
* If CONFIG_FUNCTION_TRACER is not set, CONFIG_FPROBE is disabled too.
|
|
* But user of fprobe may keep embedding the struct fprobe on their own
|
|
* code. To avoid build error, this will keep the fprobe data structure
|
|
* defined here, but remove ftrace_ops data structure.
|
|
*/
|
|
struct ftrace_ops ops;
|
|
#endif
|
|
unsigned long nmissed;
|
|
unsigned int flags;
|
|
struct rethook *rethook;
|
|
|
|
void (*entry_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs);
|
|
void (*exit_handler)(struct fprobe *fp, unsigned long entry_ip, struct pt_regs *regs);
|
|
};
|
|
|
|
#define FPROBE_FL_DISABLED 1
|
|
|
|
static inline bool fprobe_disabled(struct fprobe *fp)
|
|
{
|
|
return (fp) ? fp->flags & FPROBE_FL_DISABLED : false;
|
|
}
|
|
|
|
#ifdef CONFIG_FPROBE
|
|
int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter);
|
|
int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num);
|
|
int register_fprobe_syms(struct fprobe *fp, const char **syms, int num);
|
|
int unregister_fprobe(struct fprobe *fp);
|
|
#else
|
|
static inline int register_fprobe(struct fprobe *fp, const char *filter, const char *notfilter)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
static inline int register_fprobe_ips(struct fprobe *fp, unsigned long *addrs, int num)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
static inline int register_fprobe_syms(struct fprobe *fp, const char **syms, int num)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
static inline int unregister_fprobe(struct fprobe *fp)
|
|
{
|
|
return -EOPNOTSUPP;
|
|
}
|
|
#endif
|
|
|
|
/**
|
|
* disable_fprobe() - Disable fprobe
|
|
* @fp: The fprobe to be disabled.
|
|
*
|
|
* This will soft-disable @fp. Note that this doesn't remove the ftrace
|
|
* hooks from the function entry.
|
|
*/
|
|
static inline void disable_fprobe(struct fprobe *fp)
|
|
{
|
|
if (fp)
|
|
fp->flags |= FPROBE_FL_DISABLED;
|
|
}
|
|
|
|
/**
|
|
* enable_fprobe() - Enable fprobe
|
|
* @fp: The fprobe to be enabled.
|
|
*
|
|
* This will soft-enable @fp.
|
|
*/
|
|
static inline void enable_fprobe(struct fprobe *fp)
|
|
{
|
|
if (fp)
|
|
fp->flags &= ~FPROBE_FL_DISABLED;
|
|
}
|
|
|
|
#endif
|