12025cf9eSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 200447ccdSAdrian Hunter /* 300447ccdSAdrian Hunter * thread-stack.c: Synthesize a thread's stack using call / return events 400447ccdSAdrian Hunter * Copyright (c) 2014, Intel Corporation. 500447ccdSAdrian Hunter */ 600447ccdSAdrian Hunter 792a9e4f7SAdrian Hunter #include <linux/rbtree.h> 892a9e4f7SAdrian Hunter #include <linux/list.h> 9256d92bcSAdrian Hunter #include <linux/log2.h> 10a43783aeSArnaldo Carvalho de Melo #include <errno.h> 1100447ccdSAdrian Hunter #include "thread.h" 1200447ccdSAdrian Hunter #include "event.h" 1392a9e4f7SAdrian Hunter #include "machine.h" 143c0cd952SAdrian Hunter #include "env.h" 1500447ccdSAdrian Hunter #include "util.h" 1600447ccdSAdrian Hunter #include "debug.h" 1792a9e4f7SAdrian Hunter #include "symbol.h" 1892a9e4f7SAdrian Hunter #include "comm.h" 19451db126SChris Phlipot #include "call-path.h" 2000447ccdSAdrian Hunter #include "thread-stack.h" 2100447ccdSAdrian Hunter 2292a9e4f7SAdrian Hunter #define STACK_GROWTH 2048 2392a9e4f7SAdrian Hunter 243c0cd952SAdrian Hunter /* 253c0cd952SAdrian Hunter * State of retpoline detection. 263c0cd952SAdrian Hunter * 273c0cd952SAdrian Hunter * RETPOLINE_NONE: no retpoline detection 283c0cd952SAdrian Hunter * X86_RETPOLINE_POSSIBLE: x86 retpoline possible 293c0cd952SAdrian Hunter * X86_RETPOLINE_DETECTED: x86 retpoline detected 303c0cd952SAdrian Hunter */ 313c0cd952SAdrian Hunter enum retpoline_state_t { 323c0cd952SAdrian Hunter RETPOLINE_NONE, 333c0cd952SAdrian Hunter X86_RETPOLINE_POSSIBLE, 343c0cd952SAdrian Hunter X86_RETPOLINE_DETECTED, 353c0cd952SAdrian Hunter }; 363c0cd952SAdrian Hunter 3792a9e4f7SAdrian Hunter /** 3892a9e4f7SAdrian Hunter * struct thread_stack_entry - thread stack entry. 3992a9e4f7SAdrian Hunter * @ret_addr: return address 4092a9e4f7SAdrian Hunter * @timestamp: timestamp (if known) 4192a9e4f7SAdrian Hunter * @ref: external reference (e.g. db_id of sample) 4292a9e4f7SAdrian Hunter * @branch_count: the branch count when the entry was created 43003ccdc7SAdrian Hunter * @insn_count: the instruction count when the entry was created 44003ccdc7SAdrian Hunter * @cyc_count the cycle count when the entry was created 45f435887eSAdrian Hunter * @db_id: id used for db-export 4692a9e4f7SAdrian Hunter * @cp: call path 4792a9e4f7SAdrian Hunter * @no_call: a 'call' was not seen 484d60e5e3SAdrian Hunter * @trace_end: a 'call' but trace ended 49f08046cbSAdrian Hunter * @non_call: a branch but not a 'call' to the start of a different symbol 5092a9e4f7SAdrian Hunter */ 5192a9e4f7SAdrian Hunter struct thread_stack_entry { 5292a9e4f7SAdrian Hunter u64 ret_addr; 5392a9e4f7SAdrian Hunter u64 timestamp; 5492a9e4f7SAdrian Hunter u64 ref; 5592a9e4f7SAdrian Hunter u64 branch_count; 56003ccdc7SAdrian Hunter u64 insn_count; 57003ccdc7SAdrian Hunter u64 cyc_count; 58f435887eSAdrian Hunter u64 db_id; 5992a9e4f7SAdrian Hunter struct call_path *cp; 6092a9e4f7SAdrian Hunter bool no_call; 614d60e5e3SAdrian Hunter bool trace_end; 62f08046cbSAdrian Hunter bool non_call; 6392a9e4f7SAdrian Hunter }; 6492a9e4f7SAdrian Hunter 6592a9e4f7SAdrian Hunter /** 6692a9e4f7SAdrian Hunter * struct thread_stack - thread stack constructed from 'call' and 'return' 6792a9e4f7SAdrian Hunter * branch samples. 6892a9e4f7SAdrian Hunter * @stack: array that holds the stack 6992a9e4f7SAdrian Hunter * @cnt: number of entries in the stack 7092a9e4f7SAdrian Hunter * @sz: current maximum stack size 7192a9e4f7SAdrian Hunter * @trace_nr: current trace number 7292a9e4f7SAdrian Hunter * @branch_count: running branch count 73003ccdc7SAdrian Hunter * @insn_count: running instruction count 74003ccdc7SAdrian Hunter * @cyc_count running cycle count 7592a9e4f7SAdrian Hunter * @kernel_start: kernel start address 7692a9e4f7SAdrian Hunter * @last_time: last timestamp 7792a9e4f7SAdrian Hunter * @crp: call/return processor 7892a9e4f7SAdrian Hunter * @comm: current comm 79f6060ac6SAdrian Hunter * @arr_sz: size of array if this is the first element of an array 803c0cd952SAdrian Hunter * @rstate: used to detect retpolines 8192a9e4f7SAdrian Hunter */ 8200447ccdSAdrian Hunter struct thread_stack { 8300447ccdSAdrian Hunter struct thread_stack_entry *stack; 8400447ccdSAdrian Hunter size_t cnt; 8500447ccdSAdrian Hunter size_t sz; 8600447ccdSAdrian Hunter u64 trace_nr; 8792a9e4f7SAdrian Hunter u64 branch_count; 88003ccdc7SAdrian Hunter u64 insn_count; 89003ccdc7SAdrian Hunter u64 cyc_count; 9092a9e4f7SAdrian Hunter u64 kernel_start; 9192a9e4f7SAdrian Hunter u64 last_time; 9292a9e4f7SAdrian Hunter struct call_return_processor *crp; 9392a9e4f7SAdrian Hunter struct comm *comm; 94f6060ac6SAdrian Hunter unsigned int arr_sz; 953c0cd952SAdrian Hunter enum retpoline_state_t rstate; 9600447ccdSAdrian Hunter }; 9700447ccdSAdrian Hunter 98256d92bcSAdrian Hunter /* 99256d92bcSAdrian Hunter * Assume pid == tid == 0 identifies the idle task as defined by 100256d92bcSAdrian Hunter * perf_session__register_idle_thread(). The idle task is really 1 task per cpu, 101256d92bcSAdrian Hunter * and therefore requires a stack for each cpu. 102256d92bcSAdrian Hunter */ 103256d92bcSAdrian Hunter static inline bool thread_stack__per_cpu(struct thread *thread) 104256d92bcSAdrian Hunter { 105256d92bcSAdrian Hunter return !(thread->tid || thread->pid_); 106256d92bcSAdrian Hunter } 107256d92bcSAdrian Hunter 10800447ccdSAdrian Hunter static int thread_stack__grow(struct thread_stack *ts) 10900447ccdSAdrian Hunter { 11000447ccdSAdrian Hunter struct thread_stack_entry *new_stack; 11100447ccdSAdrian Hunter size_t sz, new_sz; 11200447ccdSAdrian Hunter 11300447ccdSAdrian Hunter new_sz = ts->sz + STACK_GROWTH; 11400447ccdSAdrian Hunter sz = new_sz * sizeof(struct thread_stack_entry); 11500447ccdSAdrian Hunter 11600447ccdSAdrian Hunter new_stack = realloc(ts->stack, sz); 11700447ccdSAdrian Hunter if (!new_stack) 11800447ccdSAdrian Hunter return -ENOMEM; 11900447ccdSAdrian Hunter 12000447ccdSAdrian Hunter ts->stack = new_stack; 12100447ccdSAdrian Hunter ts->sz = new_sz; 12200447ccdSAdrian Hunter 12300447ccdSAdrian Hunter return 0; 12400447ccdSAdrian Hunter } 12500447ccdSAdrian Hunter 1262e9e8688SAdrian Hunter static int thread_stack__init(struct thread_stack *ts, struct thread *thread, 1272e9e8688SAdrian Hunter struct call_return_processor *crp) 1282e9e8688SAdrian Hunter { 1292e9e8688SAdrian Hunter int err; 1302e9e8688SAdrian Hunter 1312e9e8688SAdrian Hunter err = thread_stack__grow(ts); 1322e9e8688SAdrian Hunter if (err) 1332e9e8688SAdrian Hunter return err; 1342e9e8688SAdrian Hunter 1353c0cd952SAdrian Hunter if (thread->mg && thread->mg->machine) { 1363c0cd952SAdrian Hunter struct machine *machine = thread->mg->machine; 1373c0cd952SAdrian Hunter const char *arch = perf_env__arch(machine->env); 1383c0cd952SAdrian Hunter 1393c0cd952SAdrian Hunter ts->kernel_start = machine__kernel_start(machine); 1403c0cd952SAdrian Hunter if (!strcmp(arch, "x86")) 1413c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 1423c0cd952SAdrian Hunter } else { 1432e9e8688SAdrian Hunter ts->kernel_start = 1ULL << 63; 1443c0cd952SAdrian Hunter } 1452e9e8688SAdrian Hunter ts->crp = crp; 1462e9e8688SAdrian Hunter 1472e9e8688SAdrian Hunter return 0; 1482e9e8688SAdrian Hunter } 1492e9e8688SAdrian Hunter 150256d92bcSAdrian Hunter static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, 15192a9e4f7SAdrian Hunter struct call_return_processor *crp) 15200447ccdSAdrian Hunter { 153139f42f3SAdrian Hunter struct thread_stack *ts = thread->ts, *new_ts; 154139f42f3SAdrian Hunter unsigned int old_sz = ts ? ts->arr_sz : 0; 155139f42f3SAdrian Hunter unsigned int new_sz = 1; 15600447ccdSAdrian Hunter 157256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0) 158256d92bcSAdrian Hunter new_sz = roundup_pow_of_two(cpu + 1); 159256d92bcSAdrian Hunter 160139f42f3SAdrian Hunter if (!ts || new_sz > old_sz) { 161139f42f3SAdrian Hunter new_ts = calloc(new_sz, sizeof(*ts)); 162139f42f3SAdrian Hunter if (!new_ts) 16300447ccdSAdrian Hunter return NULL; 164139f42f3SAdrian Hunter if (ts) 165139f42f3SAdrian Hunter memcpy(new_ts, ts, old_sz * sizeof(*ts)); 166139f42f3SAdrian Hunter new_ts->arr_sz = new_sz; 167139f42f3SAdrian Hunter zfree(&thread->ts); 168139f42f3SAdrian Hunter thread->ts = new_ts; 169139f42f3SAdrian Hunter ts = new_ts; 17000447ccdSAdrian Hunter } 17100447ccdSAdrian Hunter 172256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0 && 173256d92bcSAdrian Hunter (unsigned int)cpu < ts->arr_sz) 174256d92bcSAdrian Hunter ts += cpu; 175256d92bcSAdrian Hunter 176139f42f3SAdrian Hunter if (!ts->stack && 177139f42f3SAdrian Hunter thread_stack__init(ts, thread, crp)) 178139f42f3SAdrian Hunter return NULL; 179bd8e68acSAdrian Hunter 18000447ccdSAdrian Hunter return ts; 18100447ccdSAdrian Hunter } 18200447ccdSAdrian Hunter 183256d92bcSAdrian Hunter static struct thread_stack *thread__cpu_stack(struct thread *thread, int cpu) 184bd8e68acSAdrian Hunter { 185256d92bcSAdrian Hunter struct thread_stack *ts = thread->ts; 186256d92bcSAdrian Hunter 187256d92bcSAdrian Hunter if (cpu < 0) 188256d92bcSAdrian Hunter cpu = 0; 189256d92bcSAdrian Hunter 190256d92bcSAdrian Hunter if (!ts || (unsigned int)cpu >= ts->arr_sz) 191256d92bcSAdrian Hunter return NULL; 192256d92bcSAdrian Hunter 193256d92bcSAdrian Hunter ts += cpu; 194256d92bcSAdrian Hunter 195256d92bcSAdrian Hunter if (!ts->stack) 196256d92bcSAdrian Hunter return NULL; 197256d92bcSAdrian Hunter 198256d92bcSAdrian Hunter return ts; 199256d92bcSAdrian Hunter } 200256d92bcSAdrian Hunter 201256d92bcSAdrian Hunter static inline struct thread_stack *thread__stack(struct thread *thread, 202256d92bcSAdrian Hunter int cpu) 203256d92bcSAdrian Hunter { 204256d92bcSAdrian Hunter if (!thread) 205256d92bcSAdrian Hunter return NULL; 206256d92bcSAdrian Hunter 207256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread)) 208256d92bcSAdrian Hunter return thread__cpu_stack(thread, cpu); 209256d92bcSAdrian Hunter 210256d92bcSAdrian Hunter return thread->ts; 211bd8e68acSAdrian Hunter } 212bd8e68acSAdrian Hunter 2134d60e5e3SAdrian Hunter static int thread_stack__push(struct thread_stack *ts, u64 ret_addr, 2144d60e5e3SAdrian Hunter bool trace_end) 21500447ccdSAdrian Hunter { 21600447ccdSAdrian Hunter int err = 0; 21700447ccdSAdrian Hunter 21800447ccdSAdrian Hunter if (ts->cnt == ts->sz) { 21900447ccdSAdrian Hunter err = thread_stack__grow(ts); 22000447ccdSAdrian Hunter if (err) { 22100447ccdSAdrian Hunter pr_warning("Out of memory: discarding thread stack\n"); 22200447ccdSAdrian Hunter ts->cnt = 0; 22300447ccdSAdrian Hunter } 22400447ccdSAdrian Hunter } 22500447ccdSAdrian Hunter 2264d60e5e3SAdrian Hunter ts->stack[ts->cnt].trace_end = trace_end; 22700447ccdSAdrian Hunter ts->stack[ts->cnt++].ret_addr = ret_addr; 22800447ccdSAdrian Hunter 22900447ccdSAdrian Hunter return err; 23000447ccdSAdrian Hunter } 23100447ccdSAdrian Hunter 23200447ccdSAdrian Hunter static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr) 23300447ccdSAdrian Hunter { 23400447ccdSAdrian Hunter size_t i; 23500447ccdSAdrian Hunter 23600447ccdSAdrian Hunter /* 23700447ccdSAdrian Hunter * In some cases there may be functions which are not seen to return. 23800447ccdSAdrian Hunter * For example when setjmp / longjmp has been used. Or the perf context 23900447ccdSAdrian Hunter * switch in the kernel which doesn't stop and start tracing in exactly 24000447ccdSAdrian Hunter * the same code path. When that happens the return address will be 24100447ccdSAdrian Hunter * further down the stack. If the return address is not found at all, 24200447ccdSAdrian Hunter * we assume the opposite (i.e. this is a return for a call that wasn't 24300447ccdSAdrian Hunter * seen for some reason) and leave the stack alone. 24400447ccdSAdrian Hunter */ 24500447ccdSAdrian Hunter for (i = ts->cnt; i; ) { 24600447ccdSAdrian Hunter if (ts->stack[--i].ret_addr == ret_addr) { 24700447ccdSAdrian Hunter ts->cnt = i; 24800447ccdSAdrian Hunter return; 24900447ccdSAdrian Hunter } 25000447ccdSAdrian Hunter } 25100447ccdSAdrian Hunter } 25200447ccdSAdrian Hunter 2534d60e5e3SAdrian Hunter static void thread_stack__pop_trace_end(struct thread_stack *ts) 2544d60e5e3SAdrian Hunter { 2554d60e5e3SAdrian Hunter size_t i; 2564d60e5e3SAdrian Hunter 2574d60e5e3SAdrian Hunter for (i = ts->cnt; i; ) { 2584d60e5e3SAdrian Hunter if (ts->stack[--i].trace_end) 2594d60e5e3SAdrian Hunter ts->cnt = i; 2604d60e5e3SAdrian Hunter else 2614d60e5e3SAdrian Hunter return; 2624d60e5e3SAdrian Hunter } 2634d60e5e3SAdrian Hunter } 2644d60e5e3SAdrian Hunter 26592a9e4f7SAdrian Hunter static bool thread_stack__in_kernel(struct thread_stack *ts) 26692a9e4f7SAdrian Hunter { 26792a9e4f7SAdrian Hunter if (!ts->cnt) 26892a9e4f7SAdrian Hunter return false; 26992a9e4f7SAdrian Hunter 27092a9e4f7SAdrian Hunter return ts->stack[ts->cnt - 1].cp->in_kernel; 27192a9e4f7SAdrian Hunter } 27292a9e4f7SAdrian Hunter 27392a9e4f7SAdrian Hunter static int thread_stack__call_return(struct thread *thread, 27492a9e4f7SAdrian Hunter struct thread_stack *ts, size_t idx, 27592a9e4f7SAdrian Hunter u64 timestamp, u64 ref, bool no_return) 27692a9e4f7SAdrian Hunter { 27792a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 27892a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 27992a9e4f7SAdrian Hunter struct call_return cr = { 28092a9e4f7SAdrian Hunter .thread = thread, 28192a9e4f7SAdrian Hunter .comm = ts->comm, 28292a9e4f7SAdrian Hunter .db_id = 0, 28392a9e4f7SAdrian Hunter }; 284f435887eSAdrian Hunter u64 *parent_db_id; 28592a9e4f7SAdrian Hunter 28692a9e4f7SAdrian Hunter tse = &ts->stack[idx]; 28792a9e4f7SAdrian Hunter cr.cp = tse->cp; 28892a9e4f7SAdrian Hunter cr.call_time = tse->timestamp; 28992a9e4f7SAdrian Hunter cr.return_time = timestamp; 29092a9e4f7SAdrian Hunter cr.branch_count = ts->branch_count - tse->branch_count; 291003ccdc7SAdrian Hunter cr.insn_count = ts->insn_count - tse->insn_count; 292003ccdc7SAdrian Hunter cr.cyc_count = ts->cyc_count - tse->cyc_count; 293f435887eSAdrian Hunter cr.db_id = tse->db_id; 29492a9e4f7SAdrian Hunter cr.call_ref = tse->ref; 29592a9e4f7SAdrian Hunter cr.return_ref = ref; 29692a9e4f7SAdrian Hunter if (tse->no_call) 29792a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_CALL; 29892a9e4f7SAdrian Hunter if (no_return) 29992a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_RETURN; 300f08046cbSAdrian Hunter if (tse->non_call) 301f08046cbSAdrian Hunter cr.flags |= CALL_RETURN_NON_CALL; 30292a9e4f7SAdrian Hunter 303f435887eSAdrian Hunter /* 304f435887eSAdrian Hunter * The parent db_id must be assigned before exporting the child. Note 305f435887eSAdrian Hunter * it is not possible to export the parent first because its information 306f435887eSAdrian Hunter * is not yet complete because its 'return' has not yet been processed. 307f435887eSAdrian Hunter */ 308f435887eSAdrian Hunter parent_db_id = idx ? &(tse - 1)->db_id : NULL; 309f435887eSAdrian Hunter 310f435887eSAdrian Hunter return crp->process(&cr, parent_db_id, crp->data); 31192a9e4f7SAdrian Hunter } 31292a9e4f7SAdrian Hunter 313a5499b37SAdrian Hunter static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) 31492a9e4f7SAdrian Hunter { 31592a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 31692a9e4f7SAdrian Hunter int err; 31792a9e4f7SAdrian Hunter 31892a9e4f7SAdrian Hunter if (!crp) { 31992a9e4f7SAdrian Hunter ts->cnt = 0; 32092a9e4f7SAdrian Hunter return 0; 32192a9e4f7SAdrian Hunter } 32292a9e4f7SAdrian Hunter 32392a9e4f7SAdrian Hunter while (ts->cnt) { 32492a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 32592a9e4f7SAdrian Hunter ts->last_time, 0, true); 32692a9e4f7SAdrian Hunter if (err) { 32792a9e4f7SAdrian Hunter pr_err("Error flushing thread stack!\n"); 32892a9e4f7SAdrian Hunter ts->cnt = 0; 32992a9e4f7SAdrian Hunter return err; 33092a9e4f7SAdrian Hunter } 33192a9e4f7SAdrian Hunter } 33292a9e4f7SAdrian Hunter 33392a9e4f7SAdrian Hunter return 0; 33492a9e4f7SAdrian Hunter } 33592a9e4f7SAdrian Hunter 336a5499b37SAdrian Hunter int thread_stack__flush(struct thread *thread) 337a5499b37SAdrian Hunter { 338bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 339f6060ac6SAdrian Hunter unsigned int pos; 340f6060ac6SAdrian Hunter int err = 0; 341bd8e68acSAdrian Hunter 342f6060ac6SAdrian Hunter if (ts) { 343f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) { 344f6060ac6SAdrian Hunter int ret = __thread_stack__flush(thread, ts + pos); 345a5499b37SAdrian Hunter 346f6060ac6SAdrian Hunter if (ret) 347f6060ac6SAdrian Hunter err = ret; 348f6060ac6SAdrian Hunter } 349f6060ac6SAdrian Hunter } 350f6060ac6SAdrian Hunter 351f6060ac6SAdrian Hunter return err; 352a5499b37SAdrian Hunter } 353a5499b37SAdrian Hunter 354256d92bcSAdrian Hunter int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, 35500447ccdSAdrian Hunter u64 to_ip, u16 insn_len, u64 trace_nr) 35600447ccdSAdrian Hunter { 357256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 358bd8e68acSAdrian Hunter 35900447ccdSAdrian Hunter if (!thread) 36000447ccdSAdrian Hunter return -EINVAL; 36100447ccdSAdrian Hunter 362bd8e68acSAdrian Hunter if (!ts) { 363256d92bcSAdrian Hunter ts = thread_stack__new(thread, cpu, NULL); 364bd8e68acSAdrian Hunter if (!ts) { 36500447ccdSAdrian Hunter pr_warning("Out of memory: no thread stack\n"); 36600447ccdSAdrian Hunter return -ENOMEM; 36700447ccdSAdrian Hunter } 368bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 36900447ccdSAdrian Hunter } 37000447ccdSAdrian Hunter 37100447ccdSAdrian Hunter /* 37200447ccdSAdrian Hunter * When the trace is discontinuous, the trace_nr changes. In that case 37300447ccdSAdrian Hunter * the stack might be completely invalid. Better to report nothing than 37492a9e4f7SAdrian Hunter * to report something misleading, so flush the stack. 37500447ccdSAdrian Hunter */ 376bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 377bd8e68acSAdrian Hunter if (ts->trace_nr) 378bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 379bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 38000447ccdSAdrian Hunter } 38100447ccdSAdrian Hunter 38292a9e4f7SAdrian Hunter /* Stop here if thread_stack__process() is in use */ 383bd8e68acSAdrian Hunter if (ts->crp) 38492a9e4f7SAdrian Hunter return 0; 38592a9e4f7SAdrian Hunter 38600447ccdSAdrian Hunter if (flags & PERF_IP_FLAG_CALL) { 38700447ccdSAdrian Hunter u64 ret_addr; 38800447ccdSAdrian Hunter 38900447ccdSAdrian Hunter if (!to_ip) 39000447ccdSAdrian Hunter return 0; 39100447ccdSAdrian Hunter ret_addr = from_ip + insn_len; 39200447ccdSAdrian Hunter if (ret_addr == to_ip) 39300447ccdSAdrian Hunter return 0; /* Zero-length calls are excluded */ 394bd8e68acSAdrian Hunter return thread_stack__push(ts, ret_addr, 3954d60e5e3SAdrian Hunter flags & PERF_IP_FLAG_TRACE_END); 3964d60e5e3SAdrian Hunter } else if (flags & PERF_IP_FLAG_TRACE_BEGIN) { 3974d60e5e3SAdrian Hunter /* 3984d60e5e3SAdrian Hunter * If the caller did not change the trace number (which would 3994d60e5e3SAdrian Hunter * have flushed the stack) then try to make sense of the stack. 4004d60e5e3SAdrian Hunter * Possibly, tracing began after returning to the current 4014d60e5e3SAdrian Hunter * address, so try to pop that. Also, do not expect a call made 4024d60e5e3SAdrian Hunter * when the trace ended, to return, so pop that. 4034d60e5e3SAdrian Hunter */ 404bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 405bd8e68acSAdrian Hunter thread_stack__pop_trace_end(ts); 4064d60e5e3SAdrian Hunter } else if ((flags & PERF_IP_FLAG_RETURN) && from_ip) { 407bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 40800447ccdSAdrian Hunter } 40900447ccdSAdrian Hunter 41000447ccdSAdrian Hunter return 0; 41100447ccdSAdrian Hunter } 41200447ccdSAdrian Hunter 413256d92bcSAdrian Hunter void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr) 41492a9e4f7SAdrian Hunter { 415256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 416bd8e68acSAdrian Hunter 417bd8e68acSAdrian Hunter if (!ts) 41892a9e4f7SAdrian Hunter return; 41992a9e4f7SAdrian Hunter 420bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 421bd8e68acSAdrian Hunter if (ts->trace_nr) 422bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 423bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 42492a9e4f7SAdrian Hunter } 42592a9e4f7SAdrian Hunter } 42692a9e4f7SAdrian Hunter 427f6060ac6SAdrian Hunter static void __thread_stack__free(struct thread *thread, struct thread_stack *ts) 428f6060ac6SAdrian Hunter { 429f6060ac6SAdrian Hunter __thread_stack__flush(thread, ts); 430f6060ac6SAdrian Hunter zfree(&ts->stack); 431f6060ac6SAdrian Hunter } 432f6060ac6SAdrian Hunter 433f6060ac6SAdrian Hunter static void thread_stack__reset(struct thread *thread, struct thread_stack *ts) 434f6060ac6SAdrian Hunter { 435f6060ac6SAdrian Hunter unsigned int arr_sz = ts->arr_sz; 436f6060ac6SAdrian Hunter 437f6060ac6SAdrian Hunter __thread_stack__free(thread, ts); 438f6060ac6SAdrian Hunter memset(ts, 0, sizeof(*ts)); 439f6060ac6SAdrian Hunter ts->arr_sz = arr_sz; 440f6060ac6SAdrian Hunter } 441f6060ac6SAdrian Hunter 44200447ccdSAdrian Hunter void thread_stack__free(struct thread *thread) 44300447ccdSAdrian Hunter { 444bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 445f6060ac6SAdrian Hunter unsigned int pos; 446bd8e68acSAdrian Hunter 447bd8e68acSAdrian Hunter if (ts) { 448f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) 449f6060ac6SAdrian Hunter __thread_stack__free(thread, ts + pos); 45000447ccdSAdrian Hunter zfree(&thread->ts); 45100447ccdSAdrian Hunter } 45200447ccdSAdrian Hunter } 45300447ccdSAdrian Hunter 45424248306SAdrian Hunter static inline u64 callchain_context(u64 ip, u64 kernel_start) 45500447ccdSAdrian Hunter { 45624248306SAdrian Hunter return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL; 45724248306SAdrian Hunter } 45800447ccdSAdrian Hunter 459256d92bcSAdrian Hunter void thread_stack__sample(struct thread *thread, int cpu, 460256d92bcSAdrian Hunter struct ip_callchain *chain, 46124248306SAdrian Hunter size_t sz, u64 ip, u64 kernel_start) 46224248306SAdrian Hunter { 463256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 46424248306SAdrian Hunter u64 context = callchain_context(ip, kernel_start); 46524248306SAdrian Hunter u64 last_context; 46624248306SAdrian Hunter size_t i, j; 46700447ccdSAdrian Hunter 46824248306SAdrian Hunter if (sz < 2) { 46924248306SAdrian Hunter chain->nr = 0; 47024248306SAdrian Hunter return; 47124248306SAdrian Hunter } 47200447ccdSAdrian Hunter 47324248306SAdrian Hunter chain->ips[0] = context; 47424248306SAdrian Hunter chain->ips[1] = ip; 47524248306SAdrian Hunter 476bd8e68acSAdrian Hunter if (!ts) { 47724248306SAdrian Hunter chain->nr = 2; 47824248306SAdrian Hunter return; 47924248306SAdrian Hunter } 48024248306SAdrian Hunter 48124248306SAdrian Hunter last_context = context; 48224248306SAdrian Hunter 483bd8e68acSAdrian Hunter for (i = 2, j = 1; i < sz && j <= ts->cnt; i++, j++) { 484bd8e68acSAdrian Hunter ip = ts->stack[ts->cnt - j].ret_addr; 48524248306SAdrian Hunter context = callchain_context(ip, kernel_start); 48624248306SAdrian Hunter if (context != last_context) { 48724248306SAdrian Hunter if (i >= sz - 1) 48824248306SAdrian Hunter break; 48924248306SAdrian Hunter chain->ips[i++] = context; 49024248306SAdrian Hunter last_context = context; 49124248306SAdrian Hunter } 49224248306SAdrian Hunter chain->ips[i] = ip; 49324248306SAdrian Hunter } 49424248306SAdrian Hunter 49524248306SAdrian Hunter chain->nr = i; 49600447ccdSAdrian Hunter } 49792a9e4f7SAdrian Hunter 49892a9e4f7SAdrian Hunter struct call_return_processor * 499f435887eSAdrian Hunter call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), 50092a9e4f7SAdrian Hunter void *data) 50192a9e4f7SAdrian Hunter { 50292a9e4f7SAdrian Hunter struct call_return_processor *crp; 50392a9e4f7SAdrian Hunter 50492a9e4f7SAdrian Hunter crp = zalloc(sizeof(struct call_return_processor)); 50592a9e4f7SAdrian Hunter if (!crp) 50692a9e4f7SAdrian Hunter return NULL; 50792a9e4f7SAdrian Hunter crp->cpr = call_path_root__new(); 50892a9e4f7SAdrian Hunter if (!crp->cpr) 50992a9e4f7SAdrian Hunter goto out_free; 51092a9e4f7SAdrian Hunter crp->process = process; 51192a9e4f7SAdrian Hunter crp->data = data; 51292a9e4f7SAdrian Hunter return crp; 51392a9e4f7SAdrian Hunter 51492a9e4f7SAdrian Hunter out_free: 51592a9e4f7SAdrian Hunter free(crp); 51692a9e4f7SAdrian Hunter return NULL; 51792a9e4f7SAdrian Hunter } 51892a9e4f7SAdrian Hunter 51992a9e4f7SAdrian Hunter void call_return_processor__free(struct call_return_processor *crp) 52092a9e4f7SAdrian Hunter { 52192a9e4f7SAdrian Hunter if (crp) { 52292a9e4f7SAdrian Hunter call_path_root__free(crp->cpr); 52392a9e4f7SAdrian Hunter free(crp); 52492a9e4f7SAdrian Hunter } 52592a9e4f7SAdrian Hunter } 52692a9e4f7SAdrian Hunter 52792a9e4f7SAdrian Hunter static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, 52892a9e4f7SAdrian Hunter u64 timestamp, u64 ref, struct call_path *cp, 5292dcde4e1SAdrian Hunter bool no_call, bool trace_end) 53092a9e4f7SAdrian Hunter { 53192a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 53292a9e4f7SAdrian Hunter int err; 53392a9e4f7SAdrian Hunter 534e7a3a055SAdrian Hunter if (!cp) 535e7a3a055SAdrian Hunter return -ENOMEM; 536e7a3a055SAdrian Hunter 53792a9e4f7SAdrian Hunter if (ts->cnt == ts->sz) { 53892a9e4f7SAdrian Hunter err = thread_stack__grow(ts); 53992a9e4f7SAdrian Hunter if (err) 54092a9e4f7SAdrian Hunter return err; 54192a9e4f7SAdrian Hunter } 54292a9e4f7SAdrian Hunter 54392a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt++]; 54492a9e4f7SAdrian Hunter tse->ret_addr = ret_addr; 54592a9e4f7SAdrian Hunter tse->timestamp = timestamp; 54692a9e4f7SAdrian Hunter tse->ref = ref; 54792a9e4f7SAdrian Hunter tse->branch_count = ts->branch_count; 548003ccdc7SAdrian Hunter tse->insn_count = ts->insn_count; 549003ccdc7SAdrian Hunter tse->cyc_count = ts->cyc_count; 55092a9e4f7SAdrian Hunter tse->cp = cp; 55192a9e4f7SAdrian Hunter tse->no_call = no_call; 5522dcde4e1SAdrian Hunter tse->trace_end = trace_end; 553f08046cbSAdrian Hunter tse->non_call = false; 554f435887eSAdrian Hunter tse->db_id = 0; 55592a9e4f7SAdrian Hunter 55692a9e4f7SAdrian Hunter return 0; 55792a9e4f7SAdrian Hunter } 55892a9e4f7SAdrian Hunter 55992a9e4f7SAdrian Hunter static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts, 56092a9e4f7SAdrian Hunter u64 ret_addr, u64 timestamp, u64 ref, 56192a9e4f7SAdrian Hunter struct symbol *sym) 56292a9e4f7SAdrian Hunter { 56392a9e4f7SAdrian Hunter int err; 56492a9e4f7SAdrian Hunter 56592a9e4f7SAdrian Hunter if (!ts->cnt) 56692a9e4f7SAdrian Hunter return 1; 56792a9e4f7SAdrian Hunter 56892a9e4f7SAdrian Hunter if (ts->cnt == 1) { 56992a9e4f7SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[0]; 57092a9e4f7SAdrian Hunter 57192a9e4f7SAdrian Hunter if (tse->cp->sym == sym) 57292a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 57392a9e4f7SAdrian Hunter timestamp, ref, false); 57492a9e4f7SAdrian Hunter } 57592a9e4f7SAdrian Hunter 576f08046cbSAdrian Hunter if (ts->stack[ts->cnt - 1].ret_addr == ret_addr && 577f08046cbSAdrian Hunter !ts->stack[ts->cnt - 1].non_call) { 57892a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 57992a9e4f7SAdrian Hunter timestamp, ref, false); 58092a9e4f7SAdrian Hunter } else { 58192a9e4f7SAdrian Hunter size_t i = ts->cnt - 1; 58292a9e4f7SAdrian Hunter 58392a9e4f7SAdrian Hunter while (i--) { 584f08046cbSAdrian Hunter if (ts->stack[i].ret_addr != ret_addr || 585f08046cbSAdrian Hunter ts->stack[i].non_call) 58692a9e4f7SAdrian Hunter continue; 58792a9e4f7SAdrian Hunter i += 1; 58892a9e4f7SAdrian Hunter while (ts->cnt > i) { 58992a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, 59092a9e4f7SAdrian Hunter --ts->cnt, 59192a9e4f7SAdrian Hunter timestamp, ref, 59292a9e4f7SAdrian Hunter true); 59392a9e4f7SAdrian Hunter if (err) 59492a9e4f7SAdrian Hunter return err; 59592a9e4f7SAdrian Hunter } 59692a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 59792a9e4f7SAdrian Hunter timestamp, ref, false); 59892a9e4f7SAdrian Hunter } 59992a9e4f7SAdrian Hunter } 60092a9e4f7SAdrian Hunter 60192a9e4f7SAdrian Hunter return 1; 60292a9e4f7SAdrian Hunter } 60392a9e4f7SAdrian Hunter 604e0b89511SAdrian Hunter static int thread_stack__bottom(struct thread_stack *ts, 60592a9e4f7SAdrian Hunter struct perf_sample *sample, 60692a9e4f7SAdrian Hunter struct addr_location *from_al, 60792a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 60892a9e4f7SAdrian Hunter { 60992a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 61092a9e4f7SAdrian Hunter struct call_path *cp; 61192a9e4f7SAdrian Hunter struct symbol *sym; 61292a9e4f7SAdrian Hunter u64 ip; 61392a9e4f7SAdrian Hunter 61492a9e4f7SAdrian Hunter if (sample->ip) { 61592a9e4f7SAdrian Hunter ip = sample->ip; 61692a9e4f7SAdrian Hunter sym = from_al->sym; 61792a9e4f7SAdrian Hunter } else if (sample->addr) { 61892a9e4f7SAdrian Hunter ip = sample->addr; 61992a9e4f7SAdrian Hunter sym = to_al->sym; 62092a9e4f7SAdrian Hunter } else { 62192a9e4f7SAdrian Hunter return 0; 62292a9e4f7SAdrian Hunter } 62392a9e4f7SAdrian Hunter 62492a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, &cpr->call_path, sym, ip, 62592a9e4f7SAdrian Hunter ts->kernel_start); 62692a9e4f7SAdrian Hunter 627e0b89511SAdrian Hunter return thread_stack__push_cp(ts, ip, sample->time, ref, cp, 6282dcde4e1SAdrian Hunter true, false); 62992a9e4f7SAdrian Hunter } 63092a9e4f7SAdrian Hunter 63197860b48SAdrian Hunter static int thread_stack__pop_ks(struct thread *thread, struct thread_stack *ts, 63297860b48SAdrian Hunter struct perf_sample *sample, u64 ref) 63397860b48SAdrian Hunter { 63497860b48SAdrian Hunter u64 tm = sample->time; 63597860b48SAdrian Hunter int err; 63697860b48SAdrian Hunter 63797860b48SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 63897860b48SAdrian Hunter while (thread_stack__in_kernel(ts)) { 63997860b48SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 64097860b48SAdrian Hunter tm, ref, true); 64197860b48SAdrian Hunter if (err) 64297860b48SAdrian Hunter return err; 64397860b48SAdrian Hunter } 64497860b48SAdrian Hunter 64597860b48SAdrian Hunter return 0; 64697860b48SAdrian Hunter } 64797860b48SAdrian Hunter 64892a9e4f7SAdrian Hunter static int thread_stack__no_call_return(struct thread *thread, 64992a9e4f7SAdrian Hunter struct thread_stack *ts, 65092a9e4f7SAdrian Hunter struct perf_sample *sample, 65192a9e4f7SAdrian Hunter struct addr_location *from_al, 65292a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 65392a9e4f7SAdrian Hunter { 65492a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 65590c2cda7SAdrian Hunter struct call_path *root = &cpr->call_path; 65690c2cda7SAdrian Hunter struct symbol *fsym = from_al->sym; 65790c2cda7SAdrian Hunter struct symbol *tsym = to_al->sym; 65892a9e4f7SAdrian Hunter struct call_path *cp, *parent; 65992a9e4f7SAdrian Hunter u64 ks = ts->kernel_start; 66090c2cda7SAdrian Hunter u64 addr = sample->addr; 66190c2cda7SAdrian Hunter u64 tm = sample->time; 66290c2cda7SAdrian Hunter u64 ip = sample->ip; 66392a9e4f7SAdrian Hunter int err; 66492a9e4f7SAdrian Hunter 66590c2cda7SAdrian Hunter if (ip >= ks && addr < ks) { 66692a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 667eb5d8544SAdrian Hunter err = thread_stack__pop_ks(thread, ts, sample, ref); 66892a9e4f7SAdrian Hunter if (err) 66992a9e4f7SAdrian Hunter return err; 67092a9e4f7SAdrian Hunter 67192a9e4f7SAdrian Hunter /* If the stack is empty, push the userspace address */ 67292a9e4f7SAdrian Hunter if (!ts->cnt) { 67390c2cda7SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 67490c2cda7SAdrian Hunter return thread_stack__push_cp(ts, 0, tm, ref, cp, true, 67590c2cda7SAdrian Hunter false); 67692a9e4f7SAdrian Hunter } 67790c2cda7SAdrian Hunter } else if (thread_stack__in_kernel(ts) && ip < ks) { 67892a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 679eb5d8544SAdrian Hunter err = thread_stack__pop_ks(thread, ts, sample, ref); 68092a9e4f7SAdrian Hunter if (err) 68192a9e4f7SAdrian Hunter return err; 68292a9e4f7SAdrian Hunter } 68392a9e4f7SAdrian Hunter 68492a9e4f7SAdrian Hunter if (ts->cnt) 68592a9e4f7SAdrian Hunter parent = ts->stack[ts->cnt - 1].cp; 68692a9e4f7SAdrian Hunter else 68790c2cda7SAdrian Hunter parent = root; 68892a9e4f7SAdrian Hunter 6891f35cd65SAdrian Hunter if (parent->sym == from_al->sym) { 6901f35cd65SAdrian Hunter /* 6911f35cd65SAdrian Hunter * At the bottom of the stack, assume the missing 'call' was 6921f35cd65SAdrian Hunter * before the trace started. So, pop the current symbol and push 6931f35cd65SAdrian Hunter * the 'to' symbol. 6941f35cd65SAdrian Hunter */ 6951f35cd65SAdrian Hunter if (ts->cnt == 1) { 6961f35cd65SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 6971f35cd65SAdrian Hunter tm, ref, false); 6981f35cd65SAdrian Hunter if (err) 6991f35cd65SAdrian Hunter return err; 7001f35cd65SAdrian Hunter } 7011f35cd65SAdrian Hunter 7021f35cd65SAdrian Hunter if (!ts->cnt) { 7031f35cd65SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 7041f35cd65SAdrian Hunter 7051f35cd65SAdrian Hunter return thread_stack__push_cp(ts, addr, tm, ref, cp, 7061f35cd65SAdrian Hunter true, false); 7071f35cd65SAdrian Hunter } 7081f35cd65SAdrian Hunter 7091f35cd65SAdrian Hunter /* 7101f35cd65SAdrian Hunter * Otherwise assume the 'return' is being used as a jump (e.g. 7111f35cd65SAdrian Hunter * retpoline) and just push the 'to' symbol. 7121f35cd65SAdrian Hunter */ 7131f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 7141f35cd65SAdrian Hunter 7151f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, 0, tm, ref, cp, true, false); 7161f35cd65SAdrian Hunter if (!err) 7171f35cd65SAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 7181f35cd65SAdrian Hunter 7191f35cd65SAdrian Hunter return err; 7201f35cd65SAdrian Hunter } 7211f35cd65SAdrian Hunter 7221f35cd65SAdrian Hunter /* 7231f35cd65SAdrian Hunter * Assume 'parent' has not yet returned, so push 'to', and then push and 7241f35cd65SAdrian Hunter * pop 'from'. 7251f35cd65SAdrian Hunter */ 7261f35cd65SAdrian Hunter 7271f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 72892a9e4f7SAdrian Hunter 72990c2cda7SAdrian Hunter err = thread_stack__push_cp(ts, addr, tm, ref, cp, true, false); 73092a9e4f7SAdrian Hunter if (err) 73192a9e4f7SAdrian Hunter return err; 73292a9e4f7SAdrian Hunter 7331f35cd65SAdrian Hunter cp = call_path__findnew(cpr, cp, fsym, ip, ks); 7341f35cd65SAdrian Hunter 7351f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, ip, tm, ref, cp, true, false); 7361f35cd65SAdrian Hunter if (err) 7371f35cd65SAdrian Hunter return err; 7381f35cd65SAdrian Hunter 7391f35cd65SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, tm, ref, false); 74092a9e4f7SAdrian Hunter } 74192a9e4f7SAdrian Hunter 74292a9e4f7SAdrian Hunter static int thread_stack__trace_begin(struct thread *thread, 74392a9e4f7SAdrian Hunter struct thread_stack *ts, u64 timestamp, 74492a9e4f7SAdrian Hunter u64 ref) 74592a9e4f7SAdrian Hunter { 74692a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 74792a9e4f7SAdrian Hunter int err; 74892a9e4f7SAdrian Hunter 74992a9e4f7SAdrian Hunter if (!ts->cnt) 75092a9e4f7SAdrian Hunter return 0; 75192a9e4f7SAdrian Hunter 75292a9e4f7SAdrian Hunter /* Pop trace end */ 75392a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt - 1]; 7542dcde4e1SAdrian Hunter if (tse->trace_end) { 75592a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 75692a9e4f7SAdrian Hunter timestamp, ref, false); 75792a9e4f7SAdrian Hunter if (err) 75892a9e4f7SAdrian Hunter return err; 75992a9e4f7SAdrian Hunter } 76092a9e4f7SAdrian Hunter 76192a9e4f7SAdrian Hunter return 0; 76292a9e4f7SAdrian Hunter } 76392a9e4f7SAdrian Hunter 76492a9e4f7SAdrian Hunter static int thread_stack__trace_end(struct thread_stack *ts, 76592a9e4f7SAdrian Hunter struct perf_sample *sample, u64 ref) 76692a9e4f7SAdrian Hunter { 76792a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 76892a9e4f7SAdrian Hunter struct call_path *cp; 76992a9e4f7SAdrian Hunter u64 ret_addr; 77092a9e4f7SAdrian Hunter 77192a9e4f7SAdrian Hunter /* No point having 'trace end' on the bottom of the stack */ 77292a9e4f7SAdrian Hunter if (!ts->cnt || (ts->cnt == 1 && ts->stack[0].ref == ref)) 77392a9e4f7SAdrian Hunter return 0; 77492a9e4f7SAdrian Hunter 77592a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, NULL, 0, 77692a9e4f7SAdrian Hunter ts->kernel_start); 77792a9e4f7SAdrian Hunter 77892a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 77992a9e4f7SAdrian Hunter 78092a9e4f7SAdrian Hunter return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp, 7812dcde4e1SAdrian Hunter false, true); 78292a9e4f7SAdrian Hunter } 78392a9e4f7SAdrian Hunter 7843c0cd952SAdrian Hunter static bool is_x86_retpoline(const char *name) 7853c0cd952SAdrian Hunter { 7863c0cd952SAdrian Hunter const char *p = strstr(name, "__x86_indirect_thunk_"); 7873c0cd952SAdrian Hunter 7883c0cd952SAdrian Hunter return p == name || !strcmp(name, "__indirect_thunk_start"); 7893c0cd952SAdrian Hunter } 7903c0cd952SAdrian Hunter 7913c0cd952SAdrian Hunter /* 7923c0cd952SAdrian Hunter * x86 retpoline functions pollute the call graph. This function removes them. 7933c0cd952SAdrian Hunter * This does not handle function return thunks, nor is there any improvement 7943c0cd952SAdrian Hunter * for the handling of inline thunks or extern thunks. 7953c0cd952SAdrian Hunter */ 7963c0cd952SAdrian Hunter static int thread_stack__x86_retpoline(struct thread_stack *ts, 7973c0cd952SAdrian Hunter struct perf_sample *sample, 7983c0cd952SAdrian Hunter struct addr_location *to_al) 7993c0cd952SAdrian Hunter { 8003c0cd952SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[ts->cnt - 1]; 8013c0cd952SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 8023c0cd952SAdrian Hunter struct symbol *sym = tse->cp->sym; 8033c0cd952SAdrian Hunter struct symbol *tsym = to_al->sym; 8043c0cd952SAdrian Hunter struct call_path *cp; 8053c0cd952SAdrian Hunter 8063c0cd952SAdrian Hunter if (sym && is_x86_retpoline(sym->name)) { 8073c0cd952SAdrian Hunter /* 8083c0cd952SAdrian Hunter * This is a x86 retpoline fn. It pollutes the call graph by 8093c0cd952SAdrian Hunter * showing up everywhere there is an indirect branch, but does 8103c0cd952SAdrian Hunter * not itself mean anything. Here the top-of-stack is removed, 8113c0cd952SAdrian Hunter * by decrementing the stack count, and then further down, the 8123c0cd952SAdrian Hunter * resulting top-of-stack is replaced with the actual target. 8133c0cd952SAdrian Hunter * The result is that the retpoline functions will no longer 8143c0cd952SAdrian Hunter * appear in the call graph. Note this only affects the call 8153c0cd952SAdrian Hunter * graph, since all the original branches are left unchanged. 8163c0cd952SAdrian Hunter */ 8173c0cd952SAdrian Hunter ts->cnt -= 1; 8183c0cd952SAdrian Hunter sym = ts->stack[ts->cnt - 2].cp->sym; 8193c0cd952SAdrian Hunter if (sym && sym == tsym && to_al->addr != tsym->start) { 8203c0cd952SAdrian Hunter /* 8213c0cd952SAdrian Hunter * Target is back to the middle of the symbol we came 8223c0cd952SAdrian Hunter * from so assume it is an indirect jmp and forget it 8233c0cd952SAdrian Hunter * altogether. 8243c0cd952SAdrian Hunter */ 8253c0cd952SAdrian Hunter ts->cnt -= 1; 8263c0cd952SAdrian Hunter return 0; 8273c0cd952SAdrian Hunter } 8283c0cd952SAdrian Hunter } else if (sym && sym == tsym) { 8293c0cd952SAdrian Hunter /* 8303c0cd952SAdrian Hunter * Target is back to the symbol we came from so assume it is an 8313c0cd952SAdrian Hunter * indirect jmp and forget it altogether. 8323c0cd952SAdrian Hunter */ 8333c0cd952SAdrian Hunter ts->cnt -= 1; 8343c0cd952SAdrian Hunter return 0; 8353c0cd952SAdrian Hunter } 8363c0cd952SAdrian Hunter 8373c0cd952SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 2].cp, tsym, 8383c0cd952SAdrian Hunter sample->addr, ts->kernel_start); 8393c0cd952SAdrian Hunter if (!cp) 8403c0cd952SAdrian Hunter return -ENOMEM; 8413c0cd952SAdrian Hunter 8423c0cd952SAdrian Hunter /* Replace the top-of-stack with the actual target */ 8433c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].cp = cp; 8443c0cd952SAdrian Hunter 8453c0cd952SAdrian Hunter return 0; 8463c0cd952SAdrian Hunter } 8473c0cd952SAdrian Hunter 84892a9e4f7SAdrian Hunter int thread_stack__process(struct thread *thread, struct comm *comm, 84992a9e4f7SAdrian Hunter struct perf_sample *sample, 85092a9e4f7SAdrian Hunter struct addr_location *from_al, 85192a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref, 85292a9e4f7SAdrian Hunter struct call_return_processor *crp) 85392a9e4f7SAdrian Hunter { 854256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, sample->cpu); 8553c0cd952SAdrian Hunter enum retpoline_state_t rstate; 85692a9e4f7SAdrian Hunter int err = 0; 85792a9e4f7SAdrian Hunter 85803b32cb2SAdrian Hunter if (ts && !ts->crp) { 85992a9e4f7SAdrian Hunter /* Supersede thread_stack__event() */ 860f6060ac6SAdrian Hunter thread_stack__reset(thread, ts); 86103b32cb2SAdrian Hunter ts = NULL; 86292a9e4f7SAdrian Hunter } 86303b32cb2SAdrian Hunter 86403b32cb2SAdrian Hunter if (!ts) { 865256d92bcSAdrian Hunter ts = thread_stack__new(thread, sample->cpu, crp); 866bd8e68acSAdrian Hunter if (!ts) 86792a9e4f7SAdrian Hunter return -ENOMEM; 86892a9e4f7SAdrian Hunter ts->comm = comm; 86992a9e4f7SAdrian Hunter } 87092a9e4f7SAdrian Hunter 8713c0cd952SAdrian Hunter rstate = ts->rstate; 8723c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED) 8733c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 8743c0cd952SAdrian Hunter 87592a9e4f7SAdrian Hunter /* Flush stack on exec */ 87692a9e4f7SAdrian Hunter if (ts->comm != comm && thread->pid_ == thread->tid) { 877a5499b37SAdrian Hunter err = __thread_stack__flush(thread, ts); 87892a9e4f7SAdrian Hunter if (err) 87992a9e4f7SAdrian Hunter return err; 88092a9e4f7SAdrian Hunter ts->comm = comm; 88192a9e4f7SAdrian Hunter } 88292a9e4f7SAdrian Hunter 88392a9e4f7SAdrian Hunter /* If the stack is empty, put the current symbol on the stack */ 88492a9e4f7SAdrian Hunter if (!ts->cnt) { 885e0b89511SAdrian Hunter err = thread_stack__bottom(ts, sample, from_al, to_al, ref); 88692a9e4f7SAdrian Hunter if (err) 88792a9e4f7SAdrian Hunter return err; 88892a9e4f7SAdrian Hunter } 88992a9e4f7SAdrian Hunter 89092a9e4f7SAdrian Hunter ts->branch_count += 1; 891003ccdc7SAdrian Hunter ts->insn_count += sample->insn_cnt; 892003ccdc7SAdrian Hunter ts->cyc_count += sample->cyc_cnt; 89392a9e4f7SAdrian Hunter ts->last_time = sample->time; 89492a9e4f7SAdrian Hunter 89592a9e4f7SAdrian Hunter if (sample->flags & PERF_IP_FLAG_CALL) { 8962dcde4e1SAdrian Hunter bool trace_end = sample->flags & PERF_IP_FLAG_TRACE_END; 89792a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 89892a9e4f7SAdrian Hunter struct call_path *cp; 89992a9e4f7SAdrian Hunter u64 ret_addr; 90092a9e4f7SAdrian Hunter 90192a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 90292a9e4f7SAdrian Hunter return 0; 90392a9e4f7SAdrian Hunter 90492a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 90592a9e4f7SAdrian Hunter if (ret_addr == sample->addr) 90692a9e4f7SAdrian Hunter return 0; /* Zero-length calls are excluded */ 90792a9e4f7SAdrian Hunter 90892a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 90992a9e4f7SAdrian Hunter to_al->sym, sample->addr, 91092a9e4f7SAdrian Hunter ts->kernel_start); 91192a9e4f7SAdrian Hunter err = thread_stack__push_cp(ts, ret_addr, sample->time, ref, 9122dcde4e1SAdrian Hunter cp, false, trace_end); 9133c0cd952SAdrian Hunter 9143c0cd952SAdrian Hunter /* 9153c0cd952SAdrian Hunter * A call to the same symbol but not the start of the symbol, 9163c0cd952SAdrian Hunter * may be the start of a x86 retpoline. 9173c0cd952SAdrian Hunter */ 9183c0cd952SAdrian Hunter if (!err && rstate == X86_RETPOLINE_POSSIBLE && to_al->sym && 9193c0cd952SAdrian Hunter from_al->sym == to_al->sym && 9203c0cd952SAdrian Hunter to_al->addr != to_al->sym->start) 9213c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_DETECTED; 9223c0cd952SAdrian Hunter 92392a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_RETURN) { 92497860b48SAdrian Hunter if (!sample->addr) { 92597860b48SAdrian Hunter u32 return_from_kernel = PERF_IP_FLAG_SYSCALLRET | 92697860b48SAdrian Hunter PERF_IP_FLAG_INTERRUPT; 92797860b48SAdrian Hunter 92897860b48SAdrian Hunter if (!(sample->flags & return_from_kernel)) 92997860b48SAdrian Hunter return 0; 93097860b48SAdrian Hunter 93197860b48SAdrian Hunter /* Pop kernel stack */ 93297860b48SAdrian Hunter return thread_stack__pop_ks(thread, ts, sample, ref); 93397860b48SAdrian Hunter } 93497860b48SAdrian Hunter 93597860b48SAdrian Hunter if (!sample->ip) 93692a9e4f7SAdrian Hunter return 0; 93792a9e4f7SAdrian Hunter 9383c0cd952SAdrian Hunter /* x86 retpoline 'return' doesn't match the stack */ 9393c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED && ts->cnt > 2 && 9403c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].ret_addr != sample->addr) 9413c0cd952SAdrian Hunter return thread_stack__x86_retpoline(ts, sample, to_al); 9423c0cd952SAdrian Hunter 94392a9e4f7SAdrian Hunter err = thread_stack__pop_cp(thread, ts, sample->addr, 94492a9e4f7SAdrian Hunter sample->time, ref, from_al->sym); 94592a9e4f7SAdrian Hunter if (err) { 94692a9e4f7SAdrian Hunter if (err < 0) 94792a9e4f7SAdrian Hunter return err; 94892a9e4f7SAdrian Hunter err = thread_stack__no_call_return(thread, ts, sample, 94992a9e4f7SAdrian Hunter from_al, to_al, ref); 95092a9e4f7SAdrian Hunter } 95192a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_BEGIN) { 95292a9e4f7SAdrian Hunter err = thread_stack__trace_begin(thread, ts, sample->time, ref); 95392a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_END) { 95492a9e4f7SAdrian Hunter err = thread_stack__trace_end(ts, sample, ref); 955f08046cbSAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_BRANCH && 956f08046cbSAdrian Hunter from_al->sym != to_al->sym && to_al->sym && 957f08046cbSAdrian Hunter to_al->addr == to_al->sym->start) { 958f08046cbSAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 959f08046cbSAdrian Hunter struct call_path *cp; 960f08046cbSAdrian Hunter 961f08046cbSAdrian Hunter /* 962f08046cbSAdrian Hunter * The compiler might optimize a call/ret combination by making 963f08046cbSAdrian Hunter * it a jmp. Make that visible by recording on the stack a 964f08046cbSAdrian Hunter * branch to the start of a different symbol. Note, that means 965f08046cbSAdrian Hunter * when a ret pops the stack, all jmps must be popped off first. 966f08046cbSAdrian Hunter */ 967f08046cbSAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 968f08046cbSAdrian Hunter to_al->sym, sample->addr, 969f08046cbSAdrian Hunter ts->kernel_start); 970f08046cbSAdrian Hunter err = thread_stack__push_cp(ts, 0, sample->time, ref, cp, false, 971f08046cbSAdrian Hunter false); 972f08046cbSAdrian Hunter if (!err) 973f08046cbSAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 97492a9e4f7SAdrian Hunter } 97592a9e4f7SAdrian Hunter 97692a9e4f7SAdrian Hunter return err; 97792a9e4f7SAdrian Hunter } 978e216708dSAdrian Hunter 979256d92bcSAdrian Hunter size_t thread_stack__depth(struct thread *thread, int cpu) 980e216708dSAdrian Hunter { 981256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 982bd8e68acSAdrian Hunter 983bd8e68acSAdrian Hunter if (!ts) 984e216708dSAdrian Hunter return 0; 985bd8e68acSAdrian Hunter return ts->cnt; 986e216708dSAdrian Hunter } 987