1 // SPDX-License-Identifier: GPL-2.0
2 #include "arm64-frame-pointer-unwind-support.h"
3 #include "callchain.h"
4 #include "event.h"
5 #include "perf_regs.h" // SMPL_REG_MASK
6 #include "unwind.h"
7
8 #define perf_event_arm_regs perf_event_arm64_regs
9 #include "../../arch/arm64/include/uapi/asm/perf_regs.h"
10 #undef perf_event_arm_regs
11
12 struct entries {
13 u64 stack[2];
14 size_t length;
15 };
16
17 static bool get_leaf_frame_caller_enabled(struct perf_sample *sample)
18 {
19 return callchain_param.record_mode == CALLCHAIN_FP && sample->user_regs.regs
20 && sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_LR);
21 }
22
23 static int add_entry(struct unwind_entry *entry, void *arg)
24 {
25 struct entries *entries = arg;
26
27 entries->stack[entries->length++] = entry->ip;
28 return 0;
29 }
30
31 u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread, int usr_idx)
32 {
33 int ret;
34 struct entries entries = {};
35 struct regs_dump old_regs = sample->user_regs;
36
37 if (!get_leaf_frame_caller_enabled(sample))
38 return 0;
39
40 /*
41 * If PC and SP are not recorded, get the value of PC from the stack
42 * and set its mask. SP is not used when doing the unwinding but it
43 * still needs to be set to prevent failures.
44 */
45
46 if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_PC))) {
47 sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_PC);
48 sample->user_regs.cache_regs[PERF_REG_ARM64_PC] = sample->callchain->ips[usr_idx+1];
49 }
50
51 if (!(sample->user_regs.mask & SMPL_REG_MASK(PERF_REG_ARM64_SP))) {
52 sample->user_regs.cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_SP);
53 sample->user_regs.cache_regs[PERF_REG_ARM64_SP] = 0;
54 }
55
56 ret = unwind__get_entries(add_entry, &entries, thread, sample, 2, true);
57 sample->user_regs = old_regs;
58
59 if (ret || entries.length != 2)
60 return ret;
61
62 return callchain_param.order == ORDER_CALLER ? entries.stack[0] : entries.stack[1];
63 }
64
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.