1 // SPDX-License-Identifier: GPL-2.0 1
2 #include <linux/compat.h>
3 #include <linux/errno.h>
4 #include <linux/kernel.h>
5 #include <linux/perf_event.h>
6 #include <linux/bug.h>
7 #include <linux/sched/task_stack.h>
8
9 #include <asm/perf_regs.h>
10 #include <asm/ptrace.h>
11
12 static u64 perf_ext_regs_value(int idx)
13 {
14 switch (idx) {
15 case PERF_REG_ARM64_VG:
16 if (WARN_ON_ONCE(!system_suppo
17 return 0;
18
19 /*
20 * Vector granule is current l
21 * divided by 64.
22 */
23 return (task_get_sve_vl(curren
24 default:
25 WARN_ON_ONCE(true);
26 return 0;
27 }
28 }
29
30 u64 perf_reg_value(struct pt_regs *regs, int i
31 {
32 if (WARN_ON_ONCE((u32)idx >= PERF_REG_
33 return 0;
34
35 /*
36 * Our handling of compat tasks (PERF_
37 * we're stuck with it for ABI compati
38 *
39 * For a 32-bit consumer inspecting a
40 * the first 16 registers (see arch/ar
41 * These correspond directly to a pref
42 * 'struct pt_regs', with the exceptio
43 * (x15 corresponds to SP_hyp in the a
44 *
45 * So far, so good.
46 *
47 * The oddity arises when a 64-bit con
48 * asks for registers beyond PERF_REG_
49 * SP_usr, LR_usr and PC in the positi
50 * PC registers would normally live. T
51 * 64-bit unwinder to unwind a 32-bit
52 * how well that works in practice, so
53 *
54 * At the time we make a sample, we do
55 * 32-bit or 64-bit, so we have to cat
56 */
57 if (compat_user_mode(regs)) {
58 if ((u32)idx == PERF_REG_ARM64
59 return regs->compat_sp
60 if ((u32)idx == PERF_REG_ARM64
61 return regs->compat_lr
62 if (idx == 15)
63 return regs->pc;
64 }
65
66 if ((u32)idx == PERF_REG_ARM64_SP)
67 return regs->sp;
68
69 if ((u32)idx == PERF_REG_ARM64_PC)
70 return regs->pc;
71
72 if ((u32)idx >= PERF_REG_ARM64_MAX)
73 return perf_ext_regs_value(idx
74
75 return regs->regs[idx];
76 }
77
78 #define REG_RESERVED (~((1ULL << PERF_REG_ARM6
79
80 int perf_reg_validate(u64 mask)
81 {
82 u64 reserved_mask = REG_RESERVED;
83
84 if (system_supports_sve())
85 reserved_mask &= ~(1ULL << PER
86
87 if (!mask || mask & reserved_mask)
88 return -EINVAL;
89
90 return 0;
91 }
92
93 u64 perf_reg_abi(struct task_struct *task)
94 {
95 if (is_compat_thread(task_thread_info(
96 return PERF_SAMPLE_REGS_ABI_32
97 else
98 return PERF_SAMPLE_REGS_ABI_64
99 }
100
101 void perf_get_regs_user(struct perf_regs *regs
102 struct pt_regs *regs)
103 {
104 regs_user->regs = task_pt_regs(current
105 regs_user->abi = perf_reg_abi(current)
106 }
107
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