xref: /openbmc/linux/arch/x86/kernel/perf_regs.c (revision 12eb4683)
1 #include <linux/errno.h>
2 #include <linux/kernel.h>
3 #include <linux/sched.h>
4 #include <linux/perf_event.h>
5 #include <linux/bug.h>
6 #include <linux/stddef.h>
7 #include <asm/perf_regs.h>
8 #include <asm/ptrace.h>
9 
10 #ifdef CONFIG_X86_32
11 #define PERF_REG_X86_MAX PERF_REG_X86_32_MAX
12 #else
13 #define PERF_REG_X86_MAX PERF_REG_X86_64_MAX
14 #endif
15 
16 #define PT_REGS_OFFSET(id, r) [id] = offsetof(struct pt_regs, r)
17 
18 static unsigned int pt_regs_offset[PERF_REG_X86_MAX] = {
19 	PT_REGS_OFFSET(PERF_REG_X86_AX, ax),
20 	PT_REGS_OFFSET(PERF_REG_X86_BX, bx),
21 	PT_REGS_OFFSET(PERF_REG_X86_CX, cx),
22 	PT_REGS_OFFSET(PERF_REG_X86_DX, dx),
23 	PT_REGS_OFFSET(PERF_REG_X86_SI, si),
24 	PT_REGS_OFFSET(PERF_REG_X86_DI, di),
25 	PT_REGS_OFFSET(PERF_REG_X86_BP, bp),
26 	PT_REGS_OFFSET(PERF_REG_X86_SP, sp),
27 	PT_REGS_OFFSET(PERF_REG_X86_IP, ip),
28 	PT_REGS_OFFSET(PERF_REG_X86_FLAGS, flags),
29 	PT_REGS_OFFSET(PERF_REG_X86_CS, cs),
30 	PT_REGS_OFFSET(PERF_REG_X86_SS, ss),
31 #ifdef CONFIG_X86_32
32 	PT_REGS_OFFSET(PERF_REG_X86_DS, ds),
33 	PT_REGS_OFFSET(PERF_REG_X86_ES, es),
34 	PT_REGS_OFFSET(PERF_REG_X86_FS, fs),
35 	PT_REGS_OFFSET(PERF_REG_X86_GS, gs),
36 #else
37 	/*
38 	 * The pt_regs struct does not store
39 	 * ds, es, fs, gs in 64 bit mode.
40 	 */
41 	(unsigned int) -1,
42 	(unsigned int) -1,
43 	(unsigned int) -1,
44 	(unsigned int) -1,
45 #endif
46 #ifdef CONFIG_X86_64
47 	PT_REGS_OFFSET(PERF_REG_X86_R8, r8),
48 	PT_REGS_OFFSET(PERF_REG_X86_R9, r9),
49 	PT_REGS_OFFSET(PERF_REG_X86_R10, r10),
50 	PT_REGS_OFFSET(PERF_REG_X86_R11, r11),
51 	PT_REGS_OFFSET(PERF_REG_X86_R12, r12),
52 	PT_REGS_OFFSET(PERF_REG_X86_R13, r13),
53 	PT_REGS_OFFSET(PERF_REG_X86_R14, r14),
54 	PT_REGS_OFFSET(PERF_REG_X86_R15, r15),
55 #endif
56 };
57 
58 u64 perf_reg_value(struct pt_regs *regs, int idx)
59 {
60 	if (WARN_ON_ONCE(idx >= ARRAY_SIZE(pt_regs_offset)))
61 		return 0;
62 
63 	return regs_get_register(regs, pt_regs_offset[idx]);
64 }
65 
66 #define REG_RESERVED (~((1ULL << PERF_REG_X86_MAX) - 1ULL))
67 
68 #ifdef CONFIG_X86_32
69 int perf_reg_validate(u64 mask)
70 {
71 	if (!mask || mask & REG_RESERVED)
72 		return -EINVAL;
73 
74 	return 0;
75 }
76 
77 u64 perf_reg_abi(struct task_struct *task)
78 {
79 	return PERF_SAMPLE_REGS_ABI_32;
80 }
81 #else /* CONFIG_X86_64 */
82 #define REG_NOSUPPORT ((1ULL << PERF_REG_X86_DS) | \
83 		       (1ULL << PERF_REG_X86_ES) | \
84 		       (1ULL << PERF_REG_X86_FS) | \
85 		       (1ULL << PERF_REG_X86_GS))
86 
87 int perf_reg_validate(u64 mask)
88 {
89 	if (!mask || mask & REG_RESERVED)
90 		return -EINVAL;
91 
92 	if (mask & REG_NOSUPPORT)
93 		return -EINVAL;
94 
95 	return 0;
96 }
97 
98 u64 perf_reg_abi(struct task_struct *task)
99 {
100 	if (test_tsk_thread_flag(task, TIF_IA32))
101 		return PERF_SAMPLE_REGS_ABI_32;
102 	else
103 		return PERF_SAMPLE_REGS_ABI_64;
104 }
105 #endif /* CONFIG_X86_32 */
106