ftrace_regs.h

 1/* SPDX-License-Identifier: GPL-2.0 */
 2#ifndef _LINUX_FTRACE_REGS_H
 3#define _LINUX_FTRACE_REGS_H
 4
 5/*
 6 * For archs that just copy pt_regs in ftrace regs, it can use this default.
 7 * If an architecture does not use pt_regs, it must define all the below
 8 * accessor functions.
 9 */
10#ifndef HAVE_ARCH_FTRACE_REGS
11struct __arch_ftrace_regs {
12	struct pt_regs		regs;
13};
14
15#define arch_ftrace_regs(fregs) ((struct __arch_ftrace_regs *)(fregs))
16
17struct ftrace_regs;
18
19#define ftrace_regs_get_instruction_pointer(fregs) \
20	instruction_pointer(&arch_ftrace_regs(fregs)->regs)
21#define ftrace_regs_get_argument(fregs, n) \
22	regs_get_kernel_argument(&arch_ftrace_regs(fregs)->regs, n)
23#define ftrace_regs_get_stack_pointer(fregs) \
24	kernel_stack_pointer(&arch_ftrace_regs(fregs)->regs)
25#define ftrace_regs_get_return_value(fregs) \
26	regs_return_value(&arch_ftrace_regs(fregs)->regs)
27#define ftrace_regs_set_return_value(fregs, ret) \
28	regs_set_return_value(&arch_ftrace_regs(fregs)->regs, ret)
29#define ftrace_override_function_with_return(fregs) \
30	override_function_with_return(&arch_ftrace_regs(fregs)->regs)
31#define ftrace_regs_query_register_offset(name) \
32	regs_query_register_offset(name)
33#define ftrace_regs_get_frame_pointer(fregs) \
34	frame_pointer(&arch_ftrace_regs(fregs)->regs)
35
36static __always_inline void
37ftrace_partial_regs_update(struct ftrace_regs *fregs, struct pt_regs *regs) { }
38
39#else
40
41/*
42 * ftrace_partial_regs_update - update the original ftrace_regs from regs
43 * @fregs: The ftrace_regs to update from @regs
44 * @regs: The partial regs from ftrace_partial_regs() that was updated
45 *
46 * Some architectures have the partial regs living in the ftrace_regs
47 * structure, whereas other architectures need to make a different copy
48 * of the @regs. If a partial @regs is retrieved by ftrace_partial_regs() and
49 * if the code using @regs updates a field (like the instruction pointer or
50 * stack pointer) it may need to propagate that change to the original @fregs
51 * it retrieved the partial @regs from. Use this function to guarantee that
52 * update happens.
53 */
54static __always_inline void
55ftrace_partial_regs_update(struct ftrace_regs *fregs, struct pt_regs *regs)
56{
57	ftrace_regs_set_instruction_pointer(fregs, instruction_pointer(regs));
58	ftrace_regs_set_return_value(fregs, regs_return_value(regs));
59}
60
61#endif /* HAVE_ARCH_FTRACE_REGS */
62
63/* This can be overridden by the architectures */
64#ifndef FTRACE_REGS_MAX_ARGS
65# define FTRACE_REGS_MAX_ARGS	6
66#endif
67
68#endif /* _LINUX_FTRACE_REGS_H */