100447ccdSAdrian Hunter /* 200447ccdSAdrian Hunter * thread-stack.c: Synthesize a thread's stack using call / return events 300447ccdSAdrian Hunter * Copyright (c) 2014, Intel Corporation. 400447ccdSAdrian Hunter * 500447ccdSAdrian Hunter * This program is free software; you can redistribute it and/or modify it 600447ccdSAdrian Hunter * under the terms and conditions of the GNU General Public License, 700447ccdSAdrian Hunter * version 2, as published by the Free Software Foundation. 800447ccdSAdrian Hunter * 900447ccdSAdrian Hunter * This program is distributed in the hope it will be useful, but WITHOUT 1000447ccdSAdrian Hunter * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 1100447ccdSAdrian Hunter * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 1200447ccdSAdrian Hunter * more details. 1300447ccdSAdrian Hunter * 1400447ccdSAdrian Hunter */ 1500447ccdSAdrian Hunter 1692a9e4f7SAdrian Hunter #include <linux/rbtree.h> 1792a9e4f7SAdrian Hunter #include <linux/list.h> 18256d92bcSAdrian Hunter #include <linux/log2.h> 19a43783aeSArnaldo Carvalho de Melo #include <errno.h> 2000447ccdSAdrian Hunter #include "thread.h" 2100447ccdSAdrian Hunter #include "event.h" 2292a9e4f7SAdrian Hunter #include "machine.h" 233c0cd952SAdrian Hunter #include "env.h" 2400447ccdSAdrian Hunter #include "util.h" 2500447ccdSAdrian Hunter #include "debug.h" 2692a9e4f7SAdrian Hunter #include "symbol.h" 2792a9e4f7SAdrian Hunter #include "comm.h" 28451db126SChris Phlipot #include "call-path.h" 2900447ccdSAdrian Hunter #include "thread-stack.h" 3000447ccdSAdrian Hunter 3192a9e4f7SAdrian Hunter #define STACK_GROWTH 2048 3292a9e4f7SAdrian Hunter 333c0cd952SAdrian Hunter /* 343c0cd952SAdrian Hunter * State of retpoline detection. 353c0cd952SAdrian Hunter * 363c0cd952SAdrian Hunter * RETPOLINE_NONE: no retpoline detection 373c0cd952SAdrian Hunter * X86_RETPOLINE_POSSIBLE: x86 retpoline possible 383c0cd952SAdrian Hunter * X86_RETPOLINE_DETECTED: x86 retpoline detected 393c0cd952SAdrian Hunter */ 403c0cd952SAdrian Hunter enum retpoline_state_t { 413c0cd952SAdrian Hunter RETPOLINE_NONE, 423c0cd952SAdrian Hunter X86_RETPOLINE_POSSIBLE, 433c0cd952SAdrian Hunter X86_RETPOLINE_DETECTED, 443c0cd952SAdrian Hunter }; 453c0cd952SAdrian Hunter 4692a9e4f7SAdrian Hunter /** 4792a9e4f7SAdrian Hunter * struct thread_stack_entry - thread stack entry. 4892a9e4f7SAdrian Hunter * @ret_addr: return address 4992a9e4f7SAdrian Hunter * @timestamp: timestamp (if known) 5092a9e4f7SAdrian Hunter * @ref: external reference (e.g. db_id of sample) 5192a9e4f7SAdrian Hunter * @branch_count: the branch count when the entry was created 52f435887eSAdrian Hunter * @db_id: id used for db-export 5392a9e4f7SAdrian Hunter * @cp: call path 5492a9e4f7SAdrian Hunter * @no_call: a 'call' was not seen 554d60e5e3SAdrian Hunter * @trace_end: a 'call' but trace ended 56f08046cbSAdrian Hunter * @non_call: a branch but not a 'call' to the start of a different symbol 5792a9e4f7SAdrian Hunter */ 5892a9e4f7SAdrian Hunter struct thread_stack_entry { 5992a9e4f7SAdrian Hunter u64 ret_addr; 6092a9e4f7SAdrian Hunter u64 timestamp; 6192a9e4f7SAdrian Hunter u64 ref; 6292a9e4f7SAdrian Hunter u64 branch_count; 63f435887eSAdrian Hunter u64 db_id; 6492a9e4f7SAdrian Hunter struct call_path *cp; 6592a9e4f7SAdrian Hunter bool no_call; 664d60e5e3SAdrian Hunter bool trace_end; 67f08046cbSAdrian Hunter bool non_call; 6892a9e4f7SAdrian Hunter }; 6992a9e4f7SAdrian Hunter 7092a9e4f7SAdrian Hunter /** 7192a9e4f7SAdrian Hunter * struct thread_stack - thread stack constructed from 'call' and 'return' 7292a9e4f7SAdrian Hunter * branch samples. 7392a9e4f7SAdrian Hunter * @stack: array that holds the stack 7492a9e4f7SAdrian Hunter * @cnt: number of entries in the stack 7592a9e4f7SAdrian Hunter * @sz: current maximum stack size 7692a9e4f7SAdrian Hunter * @trace_nr: current trace number 7792a9e4f7SAdrian Hunter * @branch_count: running branch count 7892a9e4f7SAdrian Hunter * @kernel_start: kernel start address 7992a9e4f7SAdrian Hunter * @last_time: last timestamp 8092a9e4f7SAdrian Hunter * @crp: call/return processor 8192a9e4f7SAdrian Hunter * @comm: current comm 82f6060ac6SAdrian Hunter * @arr_sz: size of array if this is the first element of an array 833c0cd952SAdrian Hunter * @rstate: used to detect retpolines 8492a9e4f7SAdrian Hunter */ 8500447ccdSAdrian Hunter struct thread_stack { 8600447ccdSAdrian Hunter struct thread_stack_entry *stack; 8700447ccdSAdrian Hunter size_t cnt; 8800447ccdSAdrian Hunter size_t sz; 8900447ccdSAdrian Hunter u64 trace_nr; 9092a9e4f7SAdrian Hunter u64 branch_count; 9192a9e4f7SAdrian Hunter u64 kernel_start; 9292a9e4f7SAdrian Hunter u64 last_time; 9392a9e4f7SAdrian Hunter struct call_return_processor *crp; 9492a9e4f7SAdrian Hunter struct comm *comm; 95f6060ac6SAdrian Hunter unsigned int arr_sz; 963c0cd952SAdrian Hunter enum retpoline_state_t rstate; 9700447ccdSAdrian Hunter }; 9800447ccdSAdrian Hunter 99256d92bcSAdrian Hunter /* 100256d92bcSAdrian Hunter * Assume pid == tid == 0 identifies the idle task as defined by 101256d92bcSAdrian Hunter * perf_session__register_idle_thread(). The idle task is really 1 task per cpu, 102256d92bcSAdrian Hunter * and therefore requires a stack for each cpu. 103256d92bcSAdrian Hunter */ 104256d92bcSAdrian Hunter static inline bool thread_stack__per_cpu(struct thread *thread) 105256d92bcSAdrian Hunter { 106256d92bcSAdrian Hunter return !(thread->tid || thread->pid_); 107256d92bcSAdrian Hunter } 108256d92bcSAdrian Hunter 10900447ccdSAdrian Hunter static int thread_stack__grow(struct thread_stack *ts) 11000447ccdSAdrian Hunter { 11100447ccdSAdrian Hunter struct thread_stack_entry *new_stack; 11200447ccdSAdrian Hunter size_t sz, new_sz; 11300447ccdSAdrian Hunter 11400447ccdSAdrian Hunter new_sz = ts->sz + STACK_GROWTH; 11500447ccdSAdrian Hunter sz = new_sz * sizeof(struct thread_stack_entry); 11600447ccdSAdrian Hunter 11700447ccdSAdrian Hunter new_stack = realloc(ts->stack, sz); 11800447ccdSAdrian Hunter if (!new_stack) 11900447ccdSAdrian Hunter return -ENOMEM; 12000447ccdSAdrian Hunter 12100447ccdSAdrian Hunter ts->stack = new_stack; 12200447ccdSAdrian Hunter ts->sz = new_sz; 12300447ccdSAdrian Hunter 12400447ccdSAdrian Hunter return 0; 12500447ccdSAdrian Hunter } 12600447ccdSAdrian Hunter 1272e9e8688SAdrian Hunter static int thread_stack__init(struct thread_stack *ts, struct thread *thread, 1282e9e8688SAdrian Hunter struct call_return_processor *crp) 1292e9e8688SAdrian Hunter { 1302e9e8688SAdrian Hunter int err; 1312e9e8688SAdrian Hunter 1322e9e8688SAdrian Hunter err = thread_stack__grow(ts); 1332e9e8688SAdrian Hunter if (err) 1342e9e8688SAdrian Hunter return err; 1352e9e8688SAdrian Hunter 1363c0cd952SAdrian Hunter if (thread->mg && thread->mg->machine) { 1373c0cd952SAdrian Hunter struct machine *machine = thread->mg->machine; 1383c0cd952SAdrian Hunter const char *arch = perf_env__arch(machine->env); 1393c0cd952SAdrian Hunter 1403c0cd952SAdrian Hunter ts->kernel_start = machine__kernel_start(machine); 1413c0cd952SAdrian Hunter if (!strcmp(arch, "x86")) 1423c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 1433c0cd952SAdrian Hunter } else { 1442e9e8688SAdrian Hunter ts->kernel_start = 1ULL << 63; 1453c0cd952SAdrian Hunter } 1462e9e8688SAdrian Hunter ts->crp = crp; 1472e9e8688SAdrian Hunter 1482e9e8688SAdrian Hunter return 0; 1492e9e8688SAdrian Hunter } 1502e9e8688SAdrian Hunter 151256d92bcSAdrian Hunter static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, 15292a9e4f7SAdrian Hunter struct call_return_processor *crp) 15300447ccdSAdrian Hunter { 154139f42f3SAdrian Hunter struct thread_stack *ts = thread->ts, *new_ts; 155139f42f3SAdrian Hunter unsigned int old_sz = ts ? ts->arr_sz : 0; 156139f42f3SAdrian Hunter unsigned int new_sz = 1; 15700447ccdSAdrian Hunter 158256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0) 159256d92bcSAdrian Hunter new_sz = roundup_pow_of_two(cpu + 1); 160256d92bcSAdrian Hunter 161139f42f3SAdrian Hunter if (!ts || new_sz > old_sz) { 162139f42f3SAdrian Hunter new_ts = calloc(new_sz, sizeof(*ts)); 163139f42f3SAdrian Hunter if (!new_ts) 16400447ccdSAdrian Hunter return NULL; 165139f42f3SAdrian Hunter if (ts) 166139f42f3SAdrian Hunter memcpy(new_ts, ts, old_sz * sizeof(*ts)); 167139f42f3SAdrian Hunter new_ts->arr_sz = new_sz; 168139f42f3SAdrian Hunter zfree(&thread->ts); 169139f42f3SAdrian Hunter thread->ts = new_ts; 170139f42f3SAdrian Hunter ts = new_ts; 17100447ccdSAdrian Hunter } 17200447ccdSAdrian Hunter 173256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0 && 174256d92bcSAdrian Hunter (unsigned int)cpu < ts->arr_sz) 175256d92bcSAdrian Hunter ts += cpu; 176256d92bcSAdrian Hunter 177139f42f3SAdrian Hunter if (!ts->stack && 178139f42f3SAdrian Hunter thread_stack__init(ts, thread, crp)) 179139f42f3SAdrian Hunter return NULL; 180bd8e68acSAdrian Hunter 18100447ccdSAdrian Hunter return ts; 18200447ccdSAdrian Hunter } 18300447ccdSAdrian Hunter 184256d92bcSAdrian Hunter static struct thread_stack *thread__cpu_stack(struct thread *thread, int cpu) 185bd8e68acSAdrian Hunter { 186256d92bcSAdrian Hunter struct thread_stack *ts = thread->ts; 187256d92bcSAdrian Hunter 188256d92bcSAdrian Hunter if (cpu < 0) 189256d92bcSAdrian Hunter cpu = 0; 190256d92bcSAdrian Hunter 191256d92bcSAdrian Hunter if (!ts || (unsigned int)cpu >= ts->arr_sz) 192256d92bcSAdrian Hunter return NULL; 193256d92bcSAdrian Hunter 194256d92bcSAdrian Hunter ts += cpu; 195256d92bcSAdrian Hunter 196256d92bcSAdrian Hunter if (!ts->stack) 197256d92bcSAdrian Hunter return NULL; 198256d92bcSAdrian Hunter 199256d92bcSAdrian Hunter return ts; 200256d92bcSAdrian Hunter } 201256d92bcSAdrian Hunter 202256d92bcSAdrian Hunter static inline struct thread_stack *thread__stack(struct thread *thread, 203256d92bcSAdrian Hunter int cpu) 204256d92bcSAdrian Hunter { 205256d92bcSAdrian Hunter if (!thread) 206256d92bcSAdrian Hunter return NULL; 207256d92bcSAdrian Hunter 208256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread)) 209256d92bcSAdrian Hunter return thread__cpu_stack(thread, cpu); 210256d92bcSAdrian Hunter 211256d92bcSAdrian Hunter return thread->ts; 212bd8e68acSAdrian Hunter } 213bd8e68acSAdrian Hunter 2144d60e5e3SAdrian Hunter static int thread_stack__push(struct thread_stack *ts, u64 ret_addr, 2154d60e5e3SAdrian Hunter bool trace_end) 21600447ccdSAdrian Hunter { 21700447ccdSAdrian Hunter int err = 0; 21800447ccdSAdrian Hunter 21900447ccdSAdrian Hunter if (ts->cnt == ts->sz) { 22000447ccdSAdrian Hunter err = thread_stack__grow(ts); 22100447ccdSAdrian Hunter if (err) { 22200447ccdSAdrian Hunter pr_warning("Out of memory: discarding thread stack\n"); 22300447ccdSAdrian Hunter ts->cnt = 0; 22400447ccdSAdrian Hunter } 22500447ccdSAdrian Hunter } 22600447ccdSAdrian Hunter 2274d60e5e3SAdrian Hunter ts->stack[ts->cnt].trace_end = trace_end; 22800447ccdSAdrian Hunter ts->stack[ts->cnt++].ret_addr = ret_addr; 22900447ccdSAdrian Hunter 23000447ccdSAdrian Hunter return err; 23100447ccdSAdrian Hunter } 23200447ccdSAdrian Hunter 23300447ccdSAdrian Hunter static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr) 23400447ccdSAdrian Hunter { 23500447ccdSAdrian Hunter size_t i; 23600447ccdSAdrian Hunter 23700447ccdSAdrian Hunter /* 23800447ccdSAdrian Hunter * In some cases there may be functions which are not seen to return. 23900447ccdSAdrian Hunter * For example when setjmp / longjmp has been used. Or the perf context 24000447ccdSAdrian Hunter * switch in the kernel which doesn't stop and start tracing in exactly 24100447ccdSAdrian Hunter * the same code path. When that happens the return address will be 24200447ccdSAdrian Hunter * further down the stack. If the return address is not found at all, 24300447ccdSAdrian Hunter * we assume the opposite (i.e. this is a return for a call that wasn't 24400447ccdSAdrian Hunter * seen for some reason) and leave the stack alone. 24500447ccdSAdrian Hunter */ 24600447ccdSAdrian Hunter for (i = ts->cnt; i; ) { 24700447ccdSAdrian Hunter if (ts->stack[--i].ret_addr == ret_addr) { 24800447ccdSAdrian Hunter ts->cnt = i; 24900447ccdSAdrian Hunter return; 25000447ccdSAdrian Hunter } 25100447ccdSAdrian Hunter } 25200447ccdSAdrian Hunter } 25300447ccdSAdrian Hunter 2544d60e5e3SAdrian Hunter static void thread_stack__pop_trace_end(struct thread_stack *ts) 2554d60e5e3SAdrian Hunter { 2564d60e5e3SAdrian Hunter size_t i; 2574d60e5e3SAdrian Hunter 2584d60e5e3SAdrian Hunter for (i = ts->cnt; i; ) { 2594d60e5e3SAdrian Hunter if (ts->stack[--i].trace_end) 2604d60e5e3SAdrian Hunter ts->cnt = i; 2614d60e5e3SAdrian Hunter else 2624d60e5e3SAdrian Hunter return; 2634d60e5e3SAdrian Hunter } 2644d60e5e3SAdrian Hunter } 2654d60e5e3SAdrian Hunter 26692a9e4f7SAdrian Hunter static bool thread_stack__in_kernel(struct thread_stack *ts) 26792a9e4f7SAdrian Hunter { 26892a9e4f7SAdrian Hunter if (!ts->cnt) 26992a9e4f7SAdrian Hunter return false; 27092a9e4f7SAdrian Hunter 27192a9e4f7SAdrian Hunter return ts->stack[ts->cnt - 1].cp->in_kernel; 27292a9e4f7SAdrian Hunter } 27392a9e4f7SAdrian Hunter 27492a9e4f7SAdrian Hunter static int thread_stack__call_return(struct thread *thread, 27592a9e4f7SAdrian Hunter struct thread_stack *ts, size_t idx, 27692a9e4f7SAdrian Hunter u64 timestamp, u64 ref, bool no_return) 27792a9e4f7SAdrian Hunter { 27892a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 27992a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 28092a9e4f7SAdrian Hunter struct call_return cr = { 28192a9e4f7SAdrian Hunter .thread = thread, 28292a9e4f7SAdrian Hunter .comm = ts->comm, 28392a9e4f7SAdrian Hunter .db_id = 0, 28492a9e4f7SAdrian Hunter }; 285f435887eSAdrian Hunter u64 *parent_db_id; 28692a9e4f7SAdrian Hunter 28792a9e4f7SAdrian Hunter tse = &ts->stack[idx]; 28892a9e4f7SAdrian Hunter cr.cp = tse->cp; 28992a9e4f7SAdrian Hunter cr.call_time = tse->timestamp; 29092a9e4f7SAdrian Hunter cr.return_time = timestamp; 29192a9e4f7SAdrian Hunter cr.branch_count = ts->branch_count - tse->branch_count; 292f435887eSAdrian Hunter cr.db_id = tse->db_id; 29392a9e4f7SAdrian Hunter cr.call_ref = tse->ref; 29492a9e4f7SAdrian Hunter cr.return_ref = ref; 29592a9e4f7SAdrian Hunter if (tse->no_call) 29692a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_CALL; 29792a9e4f7SAdrian Hunter if (no_return) 29892a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_RETURN; 299f08046cbSAdrian Hunter if (tse->non_call) 300f08046cbSAdrian Hunter cr.flags |= CALL_RETURN_NON_CALL; 30192a9e4f7SAdrian Hunter 302f435887eSAdrian Hunter /* 303f435887eSAdrian Hunter * The parent db_id must be assigned before exporting the child. Note 304f435887eSAdrian Hunter * it is not possible to export the parent first because its information 305f435887eSAdrian Hunter * is not yet complete because its 'return' has not yet been processed. 306f435887eSAdrian Hunter */ 307f435887eSAdrian Hunter parent_db_id = idx ? &(tse - 1)->db_id : NULL; 308f435887eSAdrian Hunter 309f435887eSAdrian Hunter return crp->process(&cr, parent_db_id, crp->data); 31092a9e4f7SAdrian Hunter } 31192a9e4f7SAdrian Hunter 312a5499b37SAdrian Hunter static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) 31392a9e4f7SAdrian Hunter { 31492a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 31592a9e4f7SAdrian Hunter int err; 31692a9e4f7SAdrian Hunter 31792a9e4f7SAdrian Hunter if (!crp) { 31892a9e4f7SAdrian Hunter ts->cnt = 0; 31992a9e4f7SAdrian Hunter return 0; 32092a9e4f7SAdrian Hunter } 32192a9e4f7SAdrian Hunter 32292a9e4f7SAdrian Hunter while (ts->cnt) { 32392a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 32492a9e4f7SAdrian Hunter ts->last_time, 0, true); 32592a9e4f7SAdrian Hunter if (err) { 32692a9e4f7SAdrian Hunter pr_err("Error flushing thread stack!\n"); 32792a9e4f7SAdrian Hunter ts->cnt = 0; 32892a9e4f7SAdrian Hunter return err; 32992a9e4f7SAdrian Hunter } 33092a9e4f7SAdrian Hunter } 33192a9e4f7SAdrian Hunter 33292a9e4f7SAdrian Hunter return 0; 33392a9e4f7SAdrian Hunter } 33492a9e4f7SAdrian Hunter 335a5499b37SAdrian Hunter int thread_stack__flush(struct thread *thread) 336a5499b37SAdrian Hunter { 337bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 338f6060ac6SAdrian Hunter unsigned int pos; 339f6060ac6SAdrian Hunter int err = 0; 340bd8e68acSAdrian Hunter 341f6060ac6SAdrian Hunter if (ts) { 342f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) { 343f6060ac6SAdrian Hunter int ret = __thread_stack__flush(thread, ts + pos); 344a5499b37SAdrian Hunter 345f6060ac6SAdrian Hunter if (ret) 346f6060ac6SAdrian Hunter err = ret; 347f6060ac6SAdrian Hunter } 348f6060ac6SAdrian Hunter } 349f6060ac6SAdrian Hunter 350f6060ac6SAdrian Hunter return err; 351a5499b37SAdrian Hunter } 352a5499b37SAdrian Hunter 353256d92bcSAdrian Hunter int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, 35400447ccdSAdrian Hunter u64 to_ip, u16 insn_len, u64 trace_nr) 35500447ccdSAdrian Hunter { 356256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 357bd8e68acSAdrian Hunter 35800447ccdSAdrian Hunter if (!thread) 35900447ccdSAdrian Hunter return -EINVAL; 36000447ccdSAdrian Hunter 361bd8e68acSAdrian Hunter if (!ts) { 362256d92bcSAdrian Hunter ts = thread_stack__new(thread, cpu, NULL); 363bd8e68acSAdrian Hunter if (!ts) { 36400447ccdSAdrian Hunter pr_warning("Out of memory: no thread stack\n"); 36500447ccdSAdrian Hunter return -ENOMEM; 36600447ccdSAdrian Hunter } 367bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 36800447ccdSAdrian Hunter } 36900447ccdSAdrian Hunter 37000447ccdSAdrian Hunter /* 37100447ccdSAdrian Hunter * When the trace is discontinuous, the trace_nr changes. In that case 37200447ccdSAdrian Hunter * the stack might be completely invalid. Better to report nothing than 37392a9e4f7SAdrian Hunter * to report something misleading, so flush the stack. 37400447ccdSAdrian Hunter */ 375bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 376bd8e68acSAdrian Hunter if (ts->trace_nr) 377bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 378bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 37900447ccdSAdrian Hunter } 38000447ccdSAdrian Hunter 38192a9e4f7SAdrian Hunter /* Stop here if thread_stack__process() is in use */ 382bd8e68acSAdrian Hunter if (ts->crp) 38392a9e4f7SAdrian Hunter return 0; 38492a9e4f7SAdrian Hunter 38500447ccdSAdrian Hunter if (flags & PERF_IP_FLAG_CALL) { 38600447ccdSAdrian Hunter u64 ret_addr; 38700447ccdSAdrian Hunter 38800447ccdSAdrian Hunter if (!to_ip) 38900447ccdSAdrian Hunter return 0; 39000447ccdSAdrian Hunter ret_addr = from_ip + insn_len; 39100447ccdSAdrian Hunter if (ret_addr == to_ip) 39200447ccdSAdrian Hunter return 0; /* Zero-length calls are excluded */ 393bd8e68acSAdrian Hunter return thread_stack__push(ts, ret_addr, 3944d60e5e3SAdrian Hunter flags & PERF_IP_FLAG_TRACE_END); 3954d60e5e3SAdrian Hunter } else if (flags & PERF_IP_FLAG_TRACE_BEGIN) { 3964d60e5e3SAdrian Hunter /* 3974d60e5e3SAdrian Hunter * If the caller did not change the trace number (which would 3984d60e5e3SAdrian Hunter * have flushed the stack) then try to make sense of the stack. 3994d60e5e3SAdrian Hunter * Possibly, tracing began after returning to the current 4004d60e5e3SAdrian Hunter * address, so try to pop that. Also, do not expect a call made 4014d60e5e3SAdrian Hunter * when the trace ended, to return, so pop that. 4024d60e5e3SAdrian Hunter */ 403bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 404bd8e68acSAdrian Hunter thread_stack__pop_trace_end(ts); 4054d60e5e3SAdrian Hunter } else if ((flags & PERF_IP_FLAG_RETURN) && from_ip) { 406bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 40700447ccdSAdrian Hunter } 40800447ccdSAdrian Hunter 40900447ccdSAdrian Hunter return 0; 41000447ccdSAdrian Hunter } 41100447ccdSAdrian Hunter 412256d92bcSAdrian Hunter void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr) 41392a9e4f7SAdrian Hunter { 414256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 415bd8e68acSAdrian Hunter 416bd8e68acSAdrian Hunter if (!ts) 41792a9e4f7SAdrian Hunter return; 41892a9e4f7SAdrian Hunter 419bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 420bd8e68acSAdrian Hunter if (ts->trace_nr) 421bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 422bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 42392a9e4f7SAdrian Hunter } 42492a9e4f7SAdrian Hunter } 42592a9e4f7SAdrian Hunter 426f6060ac6SAdrian Hunter static void __thread_stack__free(struct thread *thread, struct thread_stack *ts) 427f6060ac6SAdrian Hunter { 428f6060ac6SAdrian Hunter __thread_stack__flush(thread, ts); 429f6060ac6SAdrian Hunter zfree(&ts->stack); 430f6060ac6SAdrian Hunter } 431f6060ac6SAdrian Hunter 432f6060ac6SAdrian Hunter static void thread_stack__reset(struct thread *thread, struct thread_stack *ts) 433f6060ac6SAdrian Hunter { 434f6060ac6SAdrian Hunter unsigned int arr_sz = ts->arr_sz; 435f6060ac6SAdrian Hunter 436f6060ac6SAdrian Hunter __thread_stack__free(thread, ts); 437f6060ac6SAdrian Hunter memset(ts, 0, sizeof(*ts)); 438f6060ac6SAdrian Hunter ts->arr_sz = arr_sz; 439f6060ac6SAdrian Hunter } 440f6060ac6SAdrian Hunter 44100447ccdSAdrian Hunter void thread_stack__free(struct thread *thread) 44200447ccdSAdrian Hunter { 443bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 444f6060ac6SAdrian Hunter unsigned int pos; 445bd8e68acSAdrian Hunter 446bd8e68acSAdrian Hunter if (ts) { 447f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) 448f6060ac6SAdrian Hunter __thread_stack__free(thread, ts + pos); 44900447ccdSAdrian Hunter zfree(&thread->ts); 45000447ccdSAdrian Hunter } 45100447ccdSAdrian Hunter } 45200447ccdSAdrian Hunter 45324248306SAdrian Hunter static inline u64 callchain_context(u64 ip, u64 kernel_start) 45400447ccdSAdrian Hunter { 45524248306SAdrian Hunter return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL; 45624248306SAdrian Hunter } 45700447ccdSAdrian Hunter 458256d92bcSAdrian Hunter void thread_stack__sample(struct thread *thread, int cpu, 459256d92bcSAdrian Hunter struct ip_callchain *chain, 46024248306SAdrian Hunter size_t sz, u64 ip, u64 kernel_start) 46124248306SAdrian Hunter { 462256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 46324248306SAdrian Hunter u64 context = callchain_context(ip, kernel_start); 46424248306SAdrian Hunter u64 last_context; 46524248306SAdrian Hunter size_t i, j; 46600447ccdSAdrian Hunter 46724248306SAdrian Hunter if (sz < 2) { 46824248306SAdrian Hunter chain->nr = 0; 46924248306SAdrian Hunter return; 47024248306SAdrian Hunter } 47100447ccdSAdrian Hunter 47224248306SAdrian Hunter chain->ips[0] = context; 47324248306SAdrian Hunter chain->ips[1] = ip; 47424248306SAdrian Hunter 475bd8e68acSAdrian Hunter if (!ts) { 47624248306SAdrian Hunter chain->nr = 2; 47724248306SAdrian Hunter return; 47824248306SAdrian Hunter } 47924248306SAdrian Hunter 48024248306SAdrian Hunter last_context = context; 48124248306SAdrian Hunter 482bd8e68acSAdrian Hunter for (i = 2, j = 1; i < sz && j <= ts->cnt; i++, j++) { 483bd8e68acSAdrian Hunter ip = ts->stack[ts->cnt - j].ret_addr; 48424248306SAdrian Hunter context = callchain_context(ip, kernel_start); 48524248306SAdrian Hunter if (context != last_context) { 48624248306SAdrian Hunter if (i >= sz - 1) 48724248306SAdrian Hunter break; 48824248306SAdrian Hunter chain->ips[i++] = context; 48924248306SAdrian Hunter last_context = context; 49024248306SAdrian Hunter } 49124248306SAdrian Hunter chain->ips[i] = ip; 49224248306SAdrian Hunter } 49324248306SAdrian Hunter 49424248306SAdrian Hunter chain->nr = i; 49500447ccdSAdrian Hunter } 49692a9e4f7SAdrian Hunter 49792a9e4f7SAdrian Hunter struct call_return_processor * 498f435887eSAdrian Hunter call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), 49992a9e4f7SAdrian Hunter void *data) 50092a9e4f7SAdrian Hunter { 50192a9e4f7SAdrian Hunter struct call_return_processor *crp; 50292a9e4f7SAdrian Hunter 50392a9e4f7SAdrian Hunter crp = zalloc(sizeof(struct call_return_processor)); 50492a9e4f7SAdrian Hunter if (!crp) 50592a9e4f7SAdrian Hunter return NULL; 50692a9e4f7SAdrian Hunter crp->cpr = call_path_root__new(); 50792a9e4f7SAdrian Hunter if (!crp->cpr) 50892a9e4f7SAdrian Hunter goto out_free; 50992a9e4f7SAdrian Hunter crp->process = process; 51092a9e4f7SAdrian Hunter crp->data = data; 51192a9e4f7SAdrian Hunter return crp; 51292a9e4f7SAdrian Hunter 51392a9e4f7SAdrian Hunter out_free: 51492a9e4f7SAdrian Hunter free(crp); 51592a9e4f7SAdrian Hunter return NULL; 51692a9e4f7SAdrian Hunter } 51792a9e4f7SAdrian Hunter 51892a9e4f7SAdrian Hunter void call_return_processor__free(struct call_return_processor *crp) 51992a9e4f7SAdrian Hunter { 52092a9e4f7SAdrian Hunter if (crp) { 52192a9e4f7SAdrian Hunter call_path_root__free(crp->cpr); 52292a9e4f7SAdrian Hunter free(crp); 52392a9e4f7SAdrian Hunter } 52492a9e4f7SAdrian Hunter } 52592a9e4f7SAdrian Hunter 52692a9e4f7SAdrian Hunter static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, 52792a9e4f7SAdrian Hunter u64 timestamp, u64 ref, struct call_path *cp, 5282dcde4e1SAdrian Hunter bool no_call, bool trace_end) 52992a9e4f7SAdrian Hunter { 53092a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 53192a9e4f7SAdrian Hunter int err; 53292a9e4f7SAdrian Hunter 533e7a3a055SAdrian Hunter if (!cp) 534e7a3a055SAdrian Hunter return -ENOMEM; 535e7a3a055SAdrian Hunter 53692a9e4f7SAdrian Hunter if (ts->cnt == ts->sz) { 53792a9e4f7SAdrian Hunter err = thread_stack__grow(ts); 53892a9e4f7SAdrian Hunter if (err) 53992a9e4f7SAdrian Hunter return err; 54092a9e4f7SAdrian Hunter } 54192a9e4f7SAdrian Hunter 54292a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt++]; 54392a9e4f7SAdrian Hunter tse->ret_addr = ret_addr; 54492a9e4f7SAdrian Hunter tse->timestamp = timestamp; 54592a9e4f7SAdrian Hunter tse->ref = ref; 54692a9e4f7SAdrian Hunter tse->branch_count = ts->branch_count; 54792a9e4f7SAdrian Hunter tse->cp = cp; 54892a9e4f7SAdrian Hunter tse->no_call = no_call; 5492dcde4e1SAdrian Hunter tse->trace_end = trace_end; 550f08046cbSAdrian Hunter tse->non_call = false; 551f435887eSAdrian Hunter tse->db_id = 0; 55292a9e4f7SAdrian Hunter 55392a9e4f7SAdrian Hunter return 0; 55492a9e4f7SAdrian Hunter } 55592a9e4f7SAdrian Hunter 55692a9e4f7SAdrian Hunter static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts, 55792a9e4f7SAdrian Hunter u64 ret_addr, u64 timestamp, u64 ref, 55892a9e4f7SAdrian Hunter struct symbol *sym) 55992a9e4f7SAdrian Hunter { 56092a9e4f7SAdrian Hunter int err; 56192a9e4f7SAdrian Hunter 56292a9e4f7SAdrian Hunter if (!ts->cnt) 56392a9e4f7SAdrian Hunter return 1; 56492a9e4f7SAdrian Hunter 56592a9e4f7SAdrian Hunter if (ts->cnt == 1) { 56692a9e4f7SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[0]; 56792a9e4f7SAdrian Hunter 56892a9e4f7SAdrian Hunter if (tse->cp->sym == sym) 56992a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 57092a9e4f7SAdrian Hunter timestamp, ref, false); 57192a9e4f7SAdrian Hunter } 57292a9e4f7SAdrian Hunter 573f08046cbSAdrian Hunter if (ts->stack[ts->cnt - 1].ret_addr == ret_addr && 574f08046cbSAdrian Hunter !ts->stack[ts->cnt - 1].non_call) { 57592a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 57692a9e4f7SAdrian Hunter timestamp, ref, false); 57792a9e4f7SAdrian Hunter } else { 57892a9e4f7SAdrian Hunter size_t i = ts->cnt - 1; 57992a9e4f7SAdrian Hunter 58092a9e4f7SAdrian Hunter while (i--) { 581f08046cbSAdrian Hunter if (ts->stack[i].ret_addr != ret_addr || 582f08046cbSAdrian Hunter ts->stack[i].non_call) 58392a9e4f7SAdrian Hunter continue; 58492a9e4f7SAdrian Hunter i += 1; 58592a9e4f7SAdrian Hunter while (ts->cnt > i) { 58692a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, 58792a9e4f7SAdrian Hunter --ts->cnt, 58892a9e4f7SAdrian Hunter timestamp, ref, 58992a9e4f7SAdrian Hunter true); 59092a9e4f7SAdrian Hunter if (err) 59192a9e4f7SAdrian Hunter return err; 59292a9e4f7SAdrian Hunter } 59392a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 59492a9e4f7SAdrian Hunter timestamp, ref, false); 59592a9e4f7SAdrian Hunter } 59692a9e4f7SAdrian Hunter } 59792a9e4f7SAdrian Hunter 59892a9e4f7SAdrian Hunter return 1; 59992a9e4f7SAdrian Hunter } 60092a9e4f7SAdrian Hunter 601e0b89511SAdrian Hunter static int thread_stack__bottom(struct thread_stack *ts, 60292a9e4f7SAdrian Hunter struct perf_sample *sample, 60392a9e4f7SAdrian Hunter struct addr_location *from_al, 60492a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 60592a9e4f7SAdrian Hunter { 60692a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 60792a9e4f7SAdrian Hunter struct call_path *cp; 60892a9e4f7SAdrian Hunter struct symbol *sym; 60992a9e4f7SAdrian Hunter u64 ip; 61092a9e4f7SAdrian Hunter 61192a9e4f7SAdrian Hunter if (sample->ip) { 61292a9e4f7SAdrian Hunter ip = sample->ip; 61392a9e4f7SAdrian Hunter sym = from_al->sym; 61492a9e4f7SAdrian Hunter } else if (sample->addr) { 61592a9e4f7SAdrian Hunter ip = sample->addr; 61692a9e4f7SAdrian Hunter sym = to_al->sym; 61792a9e4f7SAdrian Hunter } else { 61892a9e4f7SAdrian Hunter return 0; 61992a9e4f7SAdrian Hunter } 62092a9e4f7SAdrian Hunter 62192a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, &cpr->call_path, sym, ip, 62292a9e4f7SAdrian Hunter ts->kernel_start); 62392a9e4f7SAdrian Hunter 624e0b89511SAdrian Hunter return thread_stack__push_cp(ts, ip, sample->time, ref, cp, 6252dcde4e1SAdrian Hunter true, false); 62692a9e4f7SAdrian Hunter } 62792a9e4f7SAdrian Hunter 62892a9e4f7SAdrian Hunter static int thread_stack__no_call_return(struct thread *thread, 62992a9e4f7SAdrian Hunter struct thread_stack *ts, 63092a9e4f7SAdrian Hunter struct perf_sample *sample, 63192a9e4f7SAdrian Hunter struct addr_location *from_al, 63292a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 63392a9e4f7SAdrian Hunter { 63492a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 63590c2cda7SAdrian Hunter struct call_path *root = &cpr->call_path; 63690c2cda7SAdrian Hunter struct symbol *fsym = from_al->sym; 63790c2cda7SAdrian Hunter struct symbol *tsym = to_al->sym; 63892a9e4f7SAdrian Hunter struct call_path *cp, *parent; 63992a9e4f7SAdrian Hunter u64 ks = ts->kernel_start; 64090c2cda7SAdrian Hunter u64 addr = sample->addr; 64190c2cda7SAdrian Hunter u64 tm = sample->time; 64290c2cda7SAdrian Hunter u64 ip = sample->ip; 64392a9e4f7SAdrian Hunter int err; 64492a9e4f7SAdrian Hunter 64590c2cda7SAdrian Hunter if (ip >= ks && addr < ks) { 64692a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 64792a9e4f7SAdrian Hunter while (thread_stack__in_kernel(ts)) { 64892a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 64990c2cda7SAdrian Hunter tm, ref, true); 65092a9e4f7SAdrian Hunter if (err) 65192a9e4f7SAdrian Hunter return err; 65292a9e4f7SAdrian Hunter } 65392a9e4f7SAdrian Hunter 65492a9e4f7SAdrian Hunter /* If the stack is empty, push the userspace address */ 65592a9e4f7SAdrian Hunter if (!ts->cnt) { 65690c2cda7SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 65790c2cda7SAdrian Hunter return thread_stack__push_cp(ts, 0, tm, ref, cp, true, 65890c2cda7SAdrian Hunter false); 65992a9e4f7SAdrian Hunter } 66090c2cda7SAdrian Hunter } else if (thread_stack__in_kernel(ts) && ip < ks) { 66192a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 66292a9e4f7SAdrian Hunter while (thread_stack__in_kernel(ts)) { 66392a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 66490c2cda7SAdrian Hunter tm, ref, true); 66592a9e4f7SAdrian Hunter if (err) 66692a9e4f7SAdrian Hunter return err; 66792a9e4f7SAdrian Hunter } 66892a9e4f7SAdrian Hunter } 66992a9e4f7SAdrian Hunter 67092a9e4f7SAdrian Hunter if (ts->cnt) 67192a9e4f7SAdrian Hunter parent = ts->stack[ts->cnt - 1].cp; 67292a9e4f7SAdrian Hunter else 67390c2cda7SAdrian Hunter parent = root; 67492a9e4f7SAdrian Hunter 6751f35cd65SAdrian Hunter if (parent->sym == from_al->sym) { 6761f35cd65SAdrian Hunter /* 6771f35cd65SAdrian Hunter * At the bottom of the stack, assume the missing 'call' was 6781f35cd65SAdrian Hunter * before the trace started. So, pop the current symbol and push 6791f35cd65SAdrian Hunter * the 'to' symbol. 6801f35cd65SAdrian Hunter */ 6811f35cd65SAdrian Hunter if (ts->cnt == 1) { 6821f35cd65SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 6831f35cd65SAdrian Hunter tm, ref, false); 6841f35cd65SAdrian Hunter if (err) 6851f35cd65SAdrian Hunter return err; 6861f35cd65SAdrian Hunter } 6871f35cd65SAdrian Hunter 6881f35cd65SAdrian Hunter if (!ts->cnt) { 6891f35cd65SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 6901f35cd65SAdrian Hunter 6911f35cd65SAdrian Hunter return thread_stack__push_cp(ts, addr, tm, ref, cp, 6921f35cd65SAdrian Hunter true, false); 6931f35cd65SAdrian Hunter } 6941f35cd65SAdrian Hunter 6951f35cd65SAdrian Hunter /* 6961f35cd65SAdrian Hunter * Otherwise assume the 'return' is being used as a jump (e.g. 6971f35cd65SAdrian Hunter * retpoline) and just push the 'to' symbol. 6981f35cd65SAdrian Hunter */ 6991f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 7001f35cd65SAdrian Hunter 7011f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, 0, tm, ref, cp, true, false); 7021f35cd65SAdrian Hunter if (!err) 7031f35cd65SAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 7041f35cd65SAdrian Hunter 7051f35cd65SAdrian Hunter return err; 7061f35cd65SAdrian Hunter } 7071f35cd65SAdrian Hunter 7081f35cd65SAdrian Hunter /* 7091f35cd65SAdrian Hunter * Assume 'parent' has not yet returned, so push 'to', and then push and 7101f35cd65SAdrian Hunter * pop 'from'. 7111f35cd65SAdrian Hunter */ 7121f35cd65SAdrian Hunter 7131f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 71492a9e4f7SAdrian Hunter 71590c2cda7SAdrian Hunter err = thread_stack__push_cp(ts, addr, tm, ref, cp, true, false); 71692a9e4f7SAdrian Hunter if (err) 71792a9e4f7SAdrian Hunter return err; 71892a9e4f7SAdrian Hunter 7191f35cd65SAdrian Hunter cp = call_path__findnew(cpr, cp, fsym, ip, ks); 7201f35cd65SAdrian Hunter 7211f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, ip, tm, ref, cp, true, false); 7221f35cd65SAdrian Hunter if (err) 7231f35cd65SAdrian Hunter return err; 7241f35cd65SAdrian Hunter 7251f35cd65SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, tm, ref, false); 72692a9e4f7SAdrian Hunter } 72792a9e4f7SAdrian Hunter 72892a9e4f7SAdrian Hunter static int thread_stack__trace_begin(struct thread *thread, 72992a9e4f7SAdrian Hunter struct thread_stack *ts, u64 timestamp, 73092a9e4f7SAdrian Hunter u64 ref) 73192a9e4f7SAdrian Hunter { 73292a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 73392a9e4f7SAdrian Hunter int err; 73492a9e4f7SAdrian Hunter 73592a9e4f7SAdrian Hunter if (!ts->cnt) 73692a9e4f7SAdrian Hunter return 0; 73792a9e4f7SAdrian Hunter 73892a9e4f7SAdrian Hunter /* Pop trace end */ 73992a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt - 1]; 7402dcde4e1SAdrian Hunter if (tse->trace_end) { 74192a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 74292a9e4f7SAdrian Hunter timestamp, ref, false); 74392a9e4f7SAdrian Hunter if (err) 74492a9e4f7SAdrian Hunter return err; 74592a9e4f7SAdrian Hunter } 74692a9e4f7SAdrian Hunter 74792a9e4f7SAdrian Hunter return 0; 74892a9e4f7SAdrian Hunter } 74992a9e4f7SAdrian Hunter 75092a9e4f7SAdrian Hunter static int thread_stack__trace_end(struct thread_stack *ts, 75192a9e4f7SAdrian Hunter struct perf_sample *sample, u64 ref) 75292a9e4f7SAdrian Hunter { 75392a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 75492a9e4f7SAdrian Hunter struct call_path *cp; 75592a9e4f7SAdrian Hunter u64 ret_addr; 75692a9e4f7SAdrian Hunter 75792a9e4f7SAdrian Hunter /* No point having 'trace end' on the bottom of the stack */ 75892a9e4f7SAdrian Hunter if (!ts->cnt || (ts->cnt == 1 && ts->stack[0].ref == ref)) 75992a9e4f7SAdrian Hunter return 0; 76092a9e4f7SAdrian Hunter 76192a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, NULL, 0, 76292a9e4f7SAdrian Hunter ts->kernel_start); 76392a9e4f7SAdrian Hunter 76492a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 76592a9e4f7SAdrian Hunter 76692a9e4f7SAdrian Hunter return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp, 7672dcde4e1SAdrian Hunter false, true); 76892a9e4f7SAdrian Hunter } 76992a9e4f7SAdrian Hunter 7703c0cd952SAdrian Hunter static bool is_x86_retpoline(const char *name) 7713c0cd952SAdrian Hunter { 7723c0cd952SAdrian Hunter const char *p = strstr(name, "__x86_indirect_thunk_"); 7733c0cd952SAdrian Hunter 7743c0cd952SAdrian Hunter return p == name || !strcmp(name, "__indirect_thunk_start"); 7753c0cd952SAdrian Hunter } 7763c0cd952SAdrian Hunter 7773c0cd952SAdrian Hunter /* 7783c0cd952SAdrian Hunter * x86 retpoline functions pollute the call graph. This function removes them. 7793c0cd952SAdrian Hunter * This does not handle function return thunks, nor is there any improvement 7803c0cd952SAdrian Hunter * for the handling of inline thunks or extern thunks. 7813c0cd952SAdrian Hunter */ 7823c0cd952SAdrian Hunter static int thread_stack__x86_retpoline(struct thread_stack *ts, 7833c0cd952SAdrian Hunter struct perf_sample *sample, 7843c0cd952SAdrian Hunter struct addr_location *to_al) 7853c0cd952SAdrian Hunter { 7863c0cd952SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[ts->cnt - 1]; 7873c0cd952SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 7883c0cd952SAdrian Hunter struct symbol *sym = tse->cp->sym; 7893c0cd952SAdrian Hunter struct symbol *tsym = to_al->sym; 7903c0cd952SAdrian Hunter struct call_path *cp; 7913c0cd952SAdrian Hunter 7923c0cd952SAdrian Hunter if (sym && is_x86_retpoline(sym->name)) { 7933c0cd952SAdrian Hunter /* 7943c0cd952SAdrian Hunter * This is a x86 retpoline fn. It pollutes the call graph by 7953c0cd952SAdrian Hunter * showing up everywhere there is an indirect branch, but does 7963c0cd952SAdrian Hunter * not itself mean anything. Here the top-of-stack is removed, 7973c0cd952SAdrian Hunter * by decrementing the stack count, and then further down, the 7983c0cd952SAdrian Hunter * resulting top-of-stack is replaced with the actual target. 7993c0cd952SAdrian Hunter * The result is that the retpoline functions will no longer 8003c0cd952SAdrian Hunter * appear in the call graph. Note this only affects the call 8013c0cd952SAdrian Hunter * graph, since all the original branches are left unchanged. 8023c0cd952SAdrian Hunter */ 8033c0cd952SAdrian Hunter ts->cnt -= 1; 8043c0cd952SAdrian Hunter sym = ts->stack[ts->cnt - 2].cp->sym; 8053c0cd952SAdrian Hunter if (sym && sym == tsym && to_al->addr != tsym->start) { 8063c0cd952SAdrian Hunter /* 8073c0cd952SAdrian Hunter * Target is back to the middle of the symbol we came 8083c0cd952SAdrian Hunter * from so assume it is an indirect jmp and forget it 8093c0cd952SAdrian Hunter * altogether. 8103c0cd952SAdrian Hunter */ 8113c0cd952SAdrian Hunter ts->cnt -= 1; 8123c0cd952SAdrian Hunter return 0; 8133c0cd952SAdrian Hunter } 8143c0cd952SAdrian Hunter } else if (sym && sym == tsym) { 8153c0cd952SAdrian Hunter /* 8163c0cd952SAdrian Hunter * Target is back to the symbol we came from so assume it is an 8173c0cd952SAdrian Hunter * indirect jmp and forget it altogether. 8183c0cd952SAdrian Hunter */ 8193c0cd952SAdrian Hunter ts->cnt -= 1; 8203c0cd952SAdrian Hunter return 0; 8213c0cd952SAdrian Hunter } 8223c0cd952SAdrian Hunter 8233c0cd952SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 2].cp, tsym, 8243c0cd952SAdrian Hunter sample->addr, ts->kernel_start); 8253c0cd952SAdrian Hunter if (!cp) 8263c0cd952SAdrian Hunter return -ENOMEM; 8273c0cd952SAdrian Hunter 8283c0cd952SAdrian Hunter /* Replace the top-of-stack with the actual target */ 8293c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].cp = cp; 8303c0cd952SAdrian Hunter 8313c0cd952SAdrian Hunter return 0; 8323c0cd952SAdrian Hunter } 8333c0cd952SAdrian Hunter 83492a9e4f7SAdrian Hunter int thread_stack__process(struct thread *thread, struct comm *comm, 83592a9e4f7SAdrian Hunter struct perf_sample *sample, 83692a9e4f7SAdrian Hunter struct addr_location *from_al, 83792a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref, 83892a9e4f7SAdrian Hunter struct call_return_processor *crp) 83992a9e4f7SAdrian Hunter { 840256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, sample->cpu); 8413c0cd952SAdrian Hunter enum retpoline_state_t rstate; 84292a9e4f7SAdrian Hunter int err = 0; 84392a9e4f7SAdrian Hunter 84403b32cb2SAdrian Hunter if (ts && !ts->crp) { 84592a9e4f7SAdrian Hunter /* Supersede thread_stack__event() */ 846f6060ac6SAdrian Hunter thread_stack__reset(thread, ts); 84703b32cb2SAdrian Hunter ts = NULL; 84892a9e4f7SAdrian Hunter } 84903b32cb2SAdrian Hunter 85003b32cb2SAdrian Hunter if (!ts) { 851256d92bcSAdrian Hunter ts = thread_stack__new(thread, sample->cpu, crp); 852bd8e68acSAdrian Hunter if (!ts) 85392a9e4f7SAdrian Hunter return -ENOMEM; 85492a9e4f7SAdrian Hunter ts->comm = comm; 85592a9e4f7SAdrian Hunter } 85692a9e4f7SAdrian Hunter 8573c0cd952SAdrian Hunter rstate = ts->rstate; 8583c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED) 8593c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 8603c0cd952SAdrian Hunter 86192a9e4f7SAdrian Hunter /* Flush stack on exec */ 86292a9e4f7SAdrian Hunter if (ts->comm != comm && thread->pid_ == thread->tid) { 863a5499b37SAdrian Hunter err = __thread_stack__flush(thread, ts); 86492a9e4f7SAdrian Hunter if (err) 86592a9e4f7SAdrian Hunter return err; 86692a9e4f7SAdrian Hunter ts->comm = comm; 86792a9e4f7SAdrian Hunter } 86892a9e4f7SAdrian Hunter 86992a9e4f7SAdrian Hunter /* If the stack is empty, put the current symbol on the stack */ 87092a9e4f7SAdrian Hunter if (!ts->cnt) { 871e0b89511SAdrian Hunter err = thread_stack__bottom(ts, sample, from_al, to_al, ref); 87292a9e4f7SAdrian Hunter if (err) 87392a9e4f7SAdrian Hunter return err; 87492a9e4f7SAdrian Hunter } 87592a9e4f7SAdrian Hunter 87692a9e4f7SAdrian Hunter ts->branch_count += 1; 87792a9e4f7SAdrian Hunter ts->last_time = sample->time; 87892a9e4f7SAdrian Hunter 87992a9e4f7SAdrian Hunter if (sample->flags & PERF_IP_FLAG_CALL) { 8802dcde4e1SAdrian Hunter bool trace_end = sample->flags & PERF_IP_FLAG_TRACE_END; 88192a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 88292a9e4f7SAdrian Hunter struct call_path *cp; 88392a9e4f7SAdrian Hunter u64 ret_addr; 88492a9e4f7SAdrian Hunter 88592a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 88692a9e4f7SAdrian Hunter return 0; 88792a9e4f7SAdrian Hunter 88892a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 88992a9e4f7SAdrian Hunter if (ret_addr == sample->addr) 89092a9e4f7SAdrian Hunter return 0; /* Zero-length calls are excluded */ 89192a9e4f7SAdrian Hunter 89292a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 89392a9e4f7SAdrian Hunter to_al->sym, sample->addr, 89492a9e4f7SAdrian Hunter ts->kernel_start); 89592a9e4f7SAdrian Hunter err = thread_stack__push_cp(ts, ret_addr, sample->time, ref, 8962dcde4e1SAdrian Hunter cp, false, trace_end); 8973c0cd952SAdrian Hunter 8983c0cd952SAdrian Hunter /* 8993c0cd952SAdrian Hunter * A call to the same symbol but not the start of the symbol, 9003c0cd952SAdrian Hunter * may be the start of a x86 retpoline. 9013c0cd952SAdrian Hunter */ 9023c0cd952SAdrian Hunter if (!err && rstate == X86_RETPOLINE_POSSIBLE && to_al->sym && 9033c0cd952SAdrian Hunter from_al->sym == to_al->sym && 9043c0cd952SAdrian Hunter to_al->addr != to_al->sym->start) 9053c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_DETECTED; 9063c0cd952SAdrian Hunter 90792a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_RETURN) { 90892a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 90992a9e4f7SAdrian Hunter return 0; 91092a9e4f7SAdrian Hunter 9113c0cd952SAdrian Hunter /* x86 retpoline 'return' doesn't match the stack */ 9123c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED && ts->cnt > 2 && 9133c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].ret_addr != sample->addr) 9143c0cd952SAdrian Hunter return thread_stack__x86_retpoline(ts, sample, to_al); 9153c0cd952SAdrian Hunter 91692a9e4f7SAdrian Hunter err = thread_stack__pop_cp(thread, ts, sample->addr, 91792a9e4f7SAdrian Hunter sample->time, ref, from_al->sym); 91892a9e4f7SAdrian Hunter if (err) { 91992a9e4f7SAdrian Hunter if (err < 0) 92092a9e4f7SAdrian Hunter return err; 92192a9e4f7SAdrian Hunter err = thread_stack__no_call_return(thread, ts, sample, 92292a9e4f7SAdrian Hunter from_al, to_al, ref); 92392a9e4f7SAdrian Hunter } 92492a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_BEGIN) { 92592a9e4f7SAdrian Hunter err = thread_stack__trace_begin(thread, ts, sample->time, ref); 92692a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_END) { 92792a9e4f7SAdrian Hunter err = thread_stack__trace_end(ts, sample, ref); 928f08046cbSAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_BRANCH && 929f08046cbSAdrian Hunter from_al->sym != to_al->sym && to_al->sym && 930f08046cbSAdrian Hunter to_al->addr == to_al->sym->start) { 931f08046cbSAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 932f08046cbSAdrian Hunter struct call_path *cp; 933f08046cbSAdrian Hunter 934f08046cbSAdrian Hunter /* 935f08046cbSAdrian Hunter * The compiler might optimize a call/ret combination by making 936f08046cbSAdrian Hunter * it a jmp. Make that visible by recording on the stack a 937f08046cbSAdrian Hunter * branch to the start of a different symbol. Note, that means 938f08046cbSAdrian Hunter * when a ret pops the stack, all jmps must be popped off first. 939f08046cbSAdrian Hunter */ 940f08046cbSAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 941f08046cbSAdrian Hunter to_al->sym, sample->addr, 942f08046cbSAdrian Hunter ts->kernel_start); 943f08046cbSAdrian Hunter err = thread_stack__push_cp(ts, 0, sample->time, ref, cp, false, 944f08046cbSAdrian Hunter false); 945f08046cbSAdrian Hunter if (!err) 946f08046cbSAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 94792a9e4f7SAdrian Hunter } 94892a9e4f7SAdrian Hunter 94992a9e4f7SAdrian Hunter return err; 95092a9e4f7SAdrian Hunter } 951e216708dSAdrian Hunter 952256d92bcSAdrian Hunter size_t thread_stack__depth(struct thread *thread, int cpu) 953e216708dSAdrian Hunter { 954256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 955bd8e68acSAdrian Hunter 956bd8e68acSAdrian Hunter if (!ts) 957e216708dSAdrian Hunter return 0; 958bd8e68acSAdrian Hunter return ts->cnt; 959e216708dSAdrian Hunter } 960