Commit | Line | Data |
---|---|---|
b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
997963ed JP |
2 | #ifndef _ASM_X86_FRAME_H |
3 | #define _ASM_X86_FRAME_H | |
4 | ||
4625cd63 | 5 | #include <asm/asm.h> |
ecaf45ee | 6 | |
997963ed JP |
7 | /* |
8 | * These are stack frame creation macros. They should be used by every | |
9 | * callable non-leaf asm function to make kernel stack traces more reliable. | |
10 | */ | |
ec518655 | 11 | |
ecaf45ee | 12 | #ifdef CONFIG_FRAME_POINTER |
997963ed | 13 | |
ec518655 JP |
14 | #ifdef __ASSEMBLY__ |
15 | ||
997963ed JP |
16 | .macro FRAME_BEGIN |
17 | push %_ASM_BP | |
18 | _ASM_MOV %_ASM_SP, %_ASM_BP | |
19 | .endm | |
20 | ||
21 | .macro FRAME_END | |
22 | pop %_ASM_BP | |
23 | .endm | |
24 | ||
a9b3c699 PZ |
25 | #ifdef CONFIG_X86_64 |
26 | /* | |
27 | * This is a sneaky trick to help the unwinder find pt_regs on the stack. The | |
28 | * frame pointer is replaced with an encoded pointer to pt_regs. The encoding | |
29 | * is just setting the LSB, which makes it an invalid stack address and is also | |
30 | * a signal to the unwinder that it's a pt_regs pointer in disguise. | |
31 | * | |
32 | * NOTE: This macro must be used *after* PUSH_AND_CLEAR_REGS because it corrupts | |
33 | * the original rbp. | |
34 | */ | |
35 | .macro ENCODE_FRAME_POINTER ptregs_offset=0 | |
36 | leaq 1+\ptregs_offset(%rsp), %rbp | |
37 | .endm | |
38 | #else /* !CONFIG_X86_64 */ | |
39 | /* | |
40 | * This is a sneaky trick to help the unwinder find pt_regs on the stack. The | |
41 | * frame pointer is replaced with an encoded pointer to pt_regs. The encoding | |
42 | * is just clearing the MSB, which makes it an invalid stack address and is also | |
43 | * a signal to the unwinder that it's a pt_regs pointer in disguise. | |
44 | * | |
45 | * NOTE: This macro must be used *after* SAVE_ALL because it corrupts the | |
46 | * original ebp. | |
47 | */ | |
48 | .macro ENCODE_FRAME_POINTER | |
49 | mov %esp, %ebp | |
50 | andl $0x7fffffff, %ebp | |
51 | .endm | |
52 | #endif /* CONFIG_X86_64 */ | |
53 | ||
ec518655 JP |
54 | #else /* !__ASSEMBLY__ */ |
55 | ||
56 | #define FRAME_BEGIN \ | |
57 | "push %" _ASM_BP "\n" \ | |
58 | _ASM_MOV "%" _ASM_SP ", %" _ASM_BP "\n" | |
59 | ||
60 | #define FRAME_END "pop %" _ASM_BP "\n" | |
61 | ||
a9b3c699 | 62 | #ifdef CONFIG_X86_64 |
6f9885a3 | 63 | |
a9b3c699 PZ |
64 | #define ENCODE_FRAME_POINTER \ |
65 | "lea 1(%rsp), %rbp\n\t" | |
6f9885a3 JP |
66 | |
67 | static inline unsigned long encode_frame_pointer(struct pt_regs *regs) | |
68 | { | |
69 | return (unsigned long)regs + 1; | |
70 | } | |
71 | ||
a9b3c699 | 72 | #else /* !CONFIG_X86_64 */ |
6f9885a3 | 73 | |
a9b3c699 PZ |
74 | #define ENCODE_FRAME_POINTER \ |
75 | "movl %esp, %ebp\n\t" \ | |
76 | "andl $0x7fffffff, %ebp\n\t" | |
6f9885a3 JP |
77 | |
78 | static inline unsigned long encode_frame_pointer(struct pt_regs *regs) | |
79 | { | |
80 | return (unsigned long)regs & 0x7fffffff; | |
81 | } | |
82 | ||
a9b3c699 PZ |
83 | #endif /* CONFIG_X86_64 */ |
84 | ||
ec518655 JP |
85 | #endif /* __ASSEMBLY__ */ |
86 | ||
997963ed JP |
87 | #define FRAME_OFFSET __ASM_SEL(4, 8) |
88 | ||
89 | #else /* !CONFIG_FRAME_POINTER */ | |
90 | ||
a9b3c699 PZ |
91 | #ifdef __ASSEMBLY__ |
92 | ||
93 | .macro ENCODE_FRAME_POINTER ptregs_offset=0 | |
94 | .endm | |
95 | ||
96 | #else /* !__ASSEMBLY */ | |
97 | ||
98 | #define ENCODE_FRAME_POINTER | |
99 | ||
6f9885a3 JP |
100 | static inline unsigned long encode_frame_pointer(struct pt_regs *regs) |
101 | { | |
102 | return 0; | |
103 | } | |
104 | ||
a9b3c699 PZ |
105 | #endif |
106 | ||
997963ed JP |
107 | #define FRAME_BEGIN |
108 | #define FRAME_END | |
109 | #define FRAME_OFFSET 0 | |
110 | ||
111 | #endif /* CONFIG_FRAME_POINTER */ | |
7e02cb94 | 112 | |
997963ed | 113 | #endif /* _ASM_X86_FRAME_H */ |