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 #include <string.h> 8 9 #define perf_event_arm_regs perf_event_arm64_regs 10 #include "../../arch/arm64/include/uapi/asm/perf_regs.h" 11 #undef perf_event_arm_regs 12 13 struct entries { 14 u64 stack[2]; 15 size_t length; 16 }; 17 18 static bool get_leaf_frame_caller_enabled(struct perf_sample *sample) 19 { 20 struct regs_dump *regs; 21 22 if (callchain_param.record_mode != CALLCHAIN_FP) 23 return false; 24 25 regs = perf_sample__user_regs(sample); 26 return regs->regs && regs->mask & SMPL_REG_MASK(PERF_REG_ARM64_LR); 27 } 28 29 static int add_entry(struct unwind_entry *entry, void *arg) 30 { 31 struct entries *entries = arg; 32 33 entries->stack[entries->length++] = entry->ip; 34 return 0; 35 } 36 37 u64 get_leaf_frame_caller_aarch64(struct perf_sample *sample, struct thread *thread, int usr_idx) 38 { 39 int ret; 40 struct entries entries = {}; 41 struct regs_dump old_regs, *regs; 42 43 if (!get_leaf_frame_caller_enabled(sample)) 44 return 0; 45 46 /* 47 * If PC and SP are not recorded, get the value of PC from the stack 48 * and set its mask. SP is not used when doing the unwinding but it 49 * still needs to be set to prevent failures. 50 */ 51 regs = perf_sample__user_regs(sample); 52 memcpy(&old_regs, regs, sizeof(*regs)); 53 if (!(regs->mask & SMPL_REG_MASK(PERF_REG_ARM64_PC))) { 54 regs->cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_PC); 55 regs->cache_regs[PERF_REG_ARM64_PC] = sample->callchain->ips[usr_idx+1]; 56 } 57 58 if (!(regs->mask & SMPL_REG_MASK(PERF_REG_ARM64_SP))) { 59 regs->cache_mask |= SMPL_REG_MASK(PERF_REG_ARM64_SP); 60 regs->cache_regs[PERF_REG_ARM64_SP] = 0; 61 } 62 63 ret = unwind__get_entries(add_entry, &entries, thread, sample, 2, true); 64 memcpy(regs, &old_regs, sizeof(*regs)); 65 66 if (ret || entries.length != 2) 67 return ret; 68 69 return callchain_param.order == ORDER_CALLER ? entries.stack[0] : entries.stack[1]; 70 } 71