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 5292a9e4f7SAdrian Hunter * @cp: call path 5392a9e4f7SAdrian Hunter * @no_call: a 'call' was not seen 544d60e5e3SAdrian Hunter * @trace_end: a 'call' but trace ended 55f08046cbSAdrian Hunter * @non_call: a branch but not a 'call' to the start of a different symbol 5692a9e4f7SAdrian Hunter */ 5792a9e4f7SAdrian Hunter struct thread_stack_entry { 5892a9e4f7SAdrian Hunter u64 ret_addr; 5992a9e4f7SAdrian Hunter u64 timestamp; 6092a9e4f7SAdrian Hunter u64 ref; 6192a9e4f7SAdrian Hunter u64 branch_count; 6292a9e4f7SAdrian Hunter struct call_path *cp; 6392a9e4f7SAdrian Hunter bool no_call; 644d60e5e3SAdrian Hunter bool trace_end; 65f08046cbSAdrian Hunter bool non_call; 6692a9e4f7SAdrian Hunter }; 6792a9e4f7SAdrian Hunter 6892a9e4f7SAdrian Hunter /** 6992a9e4f7SAdrian Hunter * struct thread_stack - thread stack constructed from 'call' and 'return' 7092a9e4f7SAdrian Hunter * branch samples. 7192a9e4f7SAdrian Hunter * @stack: array that holds the stack 7292a9e4f7SAdrian Hunter * @cnt: number of entries in the stack 7392a9e4f7SAdrian Hunter * @sz: current maximum stack size 7492a9e4f7SAdrian Hunter * @trace_nr: current trace number 7592a9e4f7SAdrian Hunter * @branch_count: running branch count 7692a9e4f7SAdrian Hunter * @kernel_start: kernel start address 7792a9e4f7SAdrian Hunter * @last_time: last timestamp 7892a9e4f7SAdrian Hunter * @crp: call/return processor 7992a9e4f7SAdrian Hunter * @comm: current comm 80f6060ac6SAdrian Hunter * @arr_sz: size of array if this is the first element of an array 813c0cd952SAdrian Hunter * @rstate: used to detect retpolines 8292a9e4f7SAdrian Hunter */ 8300447ccdSAdrian Hunter struct thread_stack { 8400447ccdSAdrian Hunter struct thread_stack_entry *stack; 8500447ccdSAdrian Hunter size_t cnt; 8600447ccdSAdrian Hunter size_t sz; 8700447ccdSAdrian Hunter u64 trace_nr; 8892a9e4f7SAdrian Hunter u64 branch_count; 8992a9e4f7SAdrian Hunter u64 kernel_start; 9092a9e4f7SAdrian Hunter u64 last_time; 9192a9e4f7SAdrian Hunter struct call_return_processor *crp; 9292a9e4f7SAdrian Hunter struct comm *comm; 93f6060ac6SAdrian Hunter unsigned int arr_sz; 943c0cd952SAdrian Hunter enum retpoline_state_t rstate; 9500447ccdSAdrian Hunter }; 9600447ccdSAdrian Hunter 97256d92bcSAdrian Hunter /* 98256d92bcSAdrian Hunter * Assume pid == tid == 0 identifies the idle task as defined by 99256d92bcSAdrian Hunter * perf_session__register_idle_thread(). The idle task is really 1 task per cpu, 100256d92bcSAdrian Hunter * and therefore requires a stack for each cpu. 101256d92bcSAdrian Hunter */ 102256d92bcSAdrian Hunter static inline bool thread_stack__per_cpu(struct thread *thread) 103256d92bcSAdrian Hunter { 104256d92bcSAdrian Hunter return !(thread->tid || thread->pid_); 105256d92bcSAdrian Hunter } 106256d92bcSAdrian Hunter 10700447ccdSAdrian Hunter static int thread_stack__grow(struct thread_stack *ts) 10800447ccdSAdrian Hunter { 10900447ccdSAdrian Hunter struct thread_stack_entry *new_stack; 11000447ccdSAdrian Hunter size_t sz, new_sz; 11100447ccdSAdrian Hunter 11200447ccdSAdrian Hunter new_sz = ts->sz + STACK_GROWTH; 11300447ccdSAdrian Hunter sz = new_sz * sizeof(struct thread_stack_entry); 11400447ccdSAdrian Hunter 11500447ccdSAdrian Hunter new_stack = realloc(ts->stack, sz); 11600447ccdSAdrian Hunter if (!new_stack) 11700447ccdSAdrian Hunter return -ENOMEM; 11800447ccdSAdrian Hunter 11900447ccdSAdrian Hunter ts->stack = new_stack; 12000447ccdSAdrian Hunter ts->sz = new_sz; 12100447ccdSAdrian Hunter 12200447ccdSAdrian Hunter return 0; 12300447ccdSAdrian Hunter } 12400447ccdSAdrian Hunter 1252e9e8688SAdrian Hunter static int thread_stack__init(struct thread_stack *ts, struct thread *thread, 1262e9e8688SAdrian Hunter struct call_return_processor *crp) 1272e9e8688SAdrian Hunter { 1282e9e8688SAdrian Hunter int err; 1292e9e8688SAdrian Hunter 1302e9e8688SAdrian Hunter err = thread_stack__grow(ts); 1312e9e8688SAdrian Hunter if (err) 1322e9e8688SAdrian Hunter return err; 1332e9e8688SAdrian Hunter 1343c0cd952SAdrian Hunter if (thread->mg && thread->mg->machine) { 1353c0cd952SAdrian Hunter struct machine *machine = thread->mg->machine; 1363c0cd952SAdrian Hunter const char *arch = perf_env__arch(machine->env); 1373c0cd952SAdrian Hunter 1383c0cd952SAdrian Hunter ts->kernel_start = machine__kernel_start(machine); 1393c0cd952SAdrian Hunter if (!strcmp(arch, "x86")) 1403c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 1413c0cd952SAdrian Hunter } else { 1422e9e8688SAdrian Hunter ts->kernel_start = 1ULL << 63; 1433c0cd952SAdrian Hunter } 1442e9e8688SAdrian Hunter ts->crp = crp; 1452e9e8688SAdrian Hunter 1462e9e8688SAdrian Hunter return 0; 1472e9e8688SAdrian Hunter } 1482e9e8688SAdrian Hunter 149256d92bcSAdrian Hunter static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, 15092a9e4f7SAdrian Hunter struct call_return_processor *crp) 15100447ccdSAdrian Hunter { 152139f42f3SAdrian Hunter struct thread_stack *ts = thread->ts, *new_ts; 153139f42f3SAdrian Hunter unsigned int old_sz = ts ? ts->arr_sz : 0; 154139f42f3SAdrian Hunter unsigned int new_sz = 1; 15500447ccdSAdrian Hunter 156256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0) 157256d92bcSAdrian Hunter new_sz = roundup_pow_of_two(cpu + 1); 158256d92bcSAdrian Hunter 159139f42f3SAdrian Hunter if (!ts || new_sz > old_sz) { 160139f42f3SAdrian Hunter new_ts = calloc(new_sz, sizeof(*ts)); 161139f42f3SAdrian Hunter if (!new_ts) 16200447ccdSAdrian Hunter return NULL; 163139f42f3SAdrian Hunter if (ts) 164139f42f3SAdrian Hunter memcpy(new_ts, ts, old_sz * sizeof(*ts)); 165139f42f3SAdrian Hunter new_ts->arr_sz = new_sz; 166139f42f3SAdrian Hunter zfree(&thread->ts); 167139f42f3SAdrian Hunter thread->ts = new_ts; 168139f42f3SAdrian Hunter ts = new_ts; 16900447ccdSAdrian Hunter } 17000447ccdSAdrian Hunter 171256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0 && 172256d92bcSAdrian Hunter (unsigned int)cpu < ts->arr_sz) 173256d92bcSAdrian Hunter ts += cpu; 174256d92bcSAdrian Hunter 175139f42f3SAdrian Hunter if (!ts->stack && 176139f42f3SAdrian Hunter thread_stack__init(ts, thread, crp)) 177139f42f3SAdrian Hunter return NULL; 178bd8e68acSAdrian Hunter 17900447ccdSAdrian Hunter return ts; 18000447ccdSAdrian Hunter } 18100447ccdSAdrian Hunter 182256d92bcSAdrian Hunter static struct thread_stack *thread__cpu_stack(struct thread *thread, int cpu) 183bd8e68acSAdrian Hunter { 184256d92bcSAdrian Hunter struct thread_stack *ts = thread->ts; 185256d92bcSAdrian Hunter 186256d92bcSAdrian Hunter if (cpu < 0) 187256d92bcSAdrian Hunter cpu = 0; 188256d92bcSAdrian Hunter 189256d92bcSAdrian Hunter if (!ts || (unsigned int)cpu >= ts->arr_sz) 190256d92bcSAdrian Hunter return NULL; 191256d92bcSAdrian Hunter 192256d92bcSAdrian Hunter ts += cpu; 193256d92bcSAdrian Hunter 194256d92bcSAdrian Hunter if (!ts->stack) 195256d92bcSAdrian Hunter return NULL; 196256d92bcSAdrian Hunter 197256d92bcSAdrian Hunter return ts; 198256d92bcSAdrian Hunter } 199256d92bcSAdrian Hunter 200256d92bcSAdrian Hunter static inline struct thread_stack *thread__stack(struct thread *thread, 201256d92bcSAdrian Hunter int cpu) 202256d92bcSAdrian Hunter { 203256d92bcSAdrian Hunter if (!thread) 204256d92bcSAdrian Hunter return NULL; 205256d92bcSAdrian Hunter 206256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread)) 207256d92bcSAdrian Hunter return thread__cpu_stack(thread, cpu); 208256d92bcSAdrian Hunter 209256d92bcSAdrian Hunter return thread->ts; 210bd8e68acSAdrian Hunter } 211bd8e68acSAdrian Hunter 2124d60e5e3SAdrian Hunter static int thread_stack__push(struct thread_stack *ts, u64 ret_addr, 2134d60e5e3SAdrian Hunter bool trace_end) 21400447ccdSAdrian Hunter { 21500447ccdSAdrian Hunter int err = 0; 21600447ccdSAdrian Hunter 21700447ccdSAdrian Hunter if (ts->cnt == ts->sz) { 21800447ccdSAdrian Hunter err = thread_stack__grow(ts); 21900447ccdSAdrian Hunter if (err) { 22000447ccdSAdrian Hunter pr_warning("Out of memory: discarding thread stack\n"); 22100447ccdSAdrian Hunter ts->cnt = 0; 22200447ccdSAdrian Hunter } 22300447ccdSAdrian Hunter } 22400447ccdSAdrian Hunter 2254d60e5e3SAdrian Hunter ts->stack[ts->cnt].trace_end = trace_end; 22600447ccdSAdrian Hunter ts->stack[ts->cnt++].ret_addr = ret_addr; 22700447ccdSAdrian Hunter 22800447ccdSAdrian Hunter return err; 22900447ccdSAdrian Hunter } 23000447ccdSAdrian Hunter 23100447ccdSAdrian Hunter static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr) 23200447ccdSAdrian Hunter { 23300447ccdSAdrian Hunter size_t i; 23400447ccdSAdrian Hunter 23500447ccdSAdrian Hunter /* 23600447ccdSAdrian Hunter * In some cases there may be functions which are not seen to return. 23700447ccdSAdrian Hunter * For example when setjmp / longjmp has been used. Or the perf context 23800447ccdSAdrian Hunter * switch in the kernel which doesn't stop and start tracing in exactly 23900447ccdSAdrian Hunter * the same code path. When that happens the return address will be 24000447ccdSAdrian Hunter * further down the stack. If the return address is not found at all, 24100447ccdSAdrian Hunter * we assume the opposite (i.e. this is a return for a call that wasn't 24200447ccdSAdrian Hunter * seen for some reason) and leave the stack alone. 24300447ccdSAdrian Hunter */ 24400447ccdSAdrian Hunter for (i = ts->cnt; i; ) { 24500447ccdSAdrian Hunter if (ts->stack[--i].ret_addr == ret_addr) { 24600447ccdSAdrian Hunter ts->cnt = i; 24700447ccdSAdrian Hunter return; 24800447ccdSAdrian Hunter } 24900447ccdSAdrian Hunter } 25000447ccdSAdrian Hunter } 25100447ccdSAdrian Hunter 2524d60e5e3SAdrian Hunter static void thread_stack__pop_trace_end(struct thread_stack *ts) 2534d60e5e3SAdrian Hunter { 2544d60e5e3SAdrian Hunter size_t i; 2554d60e5e3SAdrian Hunter 2564d60e5e3SAdrian Hunter for (i = ts->cnt; i; ) { 2574d60e5e3SAdrian Hunter if (ts->stack[--i].trace_end) 2584d60e5e3SAdrian Hunter ts->cnt = i; 2594d60e5e3SAdrian Hunter else 2604d60e5e3SAdrian Hunter return; 2614d60e5e3SAdrian Hunter } 2624d60e5e3SAdrian Hunter } 2634d60e5e3SAdrian Hunter 26492a9e4f7SAdrian Hunter static bool thread_stack__in_kernel(struct thread_stack *ts) 26592a9e4f7SAdrian Hunter { 26692a9e4f7SAdrian Hunter if (!ts->cnt) 26792a9e4f7SAdrian Hunter return false; 26892a9e4f7SAdrian Hunter 26992a9e4f7SAdrian Hunter return ts->stack[ts->cnt - 1].cp->in_kernel; 27092a9e4f7SAdrian Hunter } 27192a9e4f7SAdrian Hunter 27292a9e4f7SAdrian Hunter static int thread_stack__call_return(struct thread *thread, 27392a9e4f7SAdrian Hunter struct thread_stack *ts, size_t idx, 27492a9e4f7SAdrian Hunter u64 timestamp, u64 ref, bool no_return) 27592a9e4f7SAdrian Hunter { 27692a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 27792a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 27892a9e4f7SAdrian Hunter struct call_return cr = { 27992a9e4f7SAdrian Hunter .thread = thread, 28092a9e4f7SAdrian Hunter .comm = ts->comm, 28192a9e4f7SAdrian Hunter .db_id = 0, 28292a9e4f7SAdrian Hunter }; 28392a9e4f7SAdrian Hunter 28492a9e4f7SAdrian Hunter tse = &ts->stack[idx]; 28592a9e4f7SAdrian Hunter cr.cp = tse->cp; 28692a9e4f7SAdrian Hunter cr.call_time = tse->timestamp; 28792a9e4f7SAdrian Hunter cr.return_time = timestamp; 28892a9e4f7SAdrian Hunter cr.branch_count = ts->branch_count - tse->branch_count; 28992a9e4f7SAdrian Hunter cr.call_ref = tse->ref; 29092a9e4f7SAdrian Hunter cr.return_ref = ref; 29192a9e4f7SAdrian Hunter if (tse->no_call) 29292a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_CALL; 29392a9e4f7SAdrian Hunter if (no_return) 29492a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_RETURN; 295f08046cbSAdrian Hunter if (tse->non_call) 296f08046cbSAdrian Hunter cr.flags |= CALL_RETURN_NON_CALL; 29792a9e4f7SAdrian Hunter 29892a9e4f7SAdrian Hunter return crp->process(&cr, crp->data); 29992a9e4f7SAdrian Hunter } 30092a9e4f7SAdrian Hunter 301a5499b37SAdrian Hunter static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) 30292a9e4f7SAdrian Hunter { 30392a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 30492a9e4f7SAdrian Hunter int err; 30592a9e4f7SAdrian Hunter 30692a9e4f7SAdrian Hunter if (!crp) { 30792a9e4f7SAdrian Hunter ts->cnt = 0; 30892a9e4f7SAdrian Hunter return 0; 30992a9e4f7SAdrian Hunter } 31092a9e4f7SAdrian Hunter 31192a9e4f7SAdrian Hunter while (ts->cnt) { 31292a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 31392a9e4f7SAdrian Hunter ts->last_time, 0, true); 31492a9e4f7SAdrian Hunter if (err) { 31592a9e4f7SAdrian Hunter pr_err("Error flushing thread stack!\n"); 31692a9e4f7SAdrian Hunter ts->cnt = 0; 31792a9e4f7SAdrian Hunter return err; 31892a9e4f7SAdrian Hunter } 31992a9e4f7SAdrian Hunter } 32092a9e4f7SAdrian Hunter 32192a9e4f7SAdrian Hunter return 0; 32292a9e4f7SAdrian Hunter } 32392a9e4f7SAdrian Hunter 324a5499b37SAdrian Hunter int thread_stack__flush(struct thread *thread) 325a5499b37SAdrian Hunter { 326bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 327f6060ac6SAdrian Hunter unsigned int pos; 328f6060ac6SAdrian Hunter int err = 0; 329bd8e68acSAdrian Hunter 330f6060ac6SAdrian Hunter if (ts) { 331f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) { 332f6060ac6SAdrian Hunter int ret = __thread_stack__flush(thread, ts + pos); 333a5499b37SAdrian Hunter 334f6060ac6SAdrian Hunter if (ret) 335f6060ac6SAdrian Hunter err = ret; 336f6060ac6SAdrian Hunter } 337f6060ac6SAdrian Hunter } 338f6060ac6SAdrian Hunter 339f6060ac6SAdrian Hunter return err; 340a5499b37SAdrian Hunter } 341a5499b37SAdrian Hunter 342256d92bcSAdrian Hunter int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, 34300447ccdSAdrian Hunter u64 to_ip, u16 insn_len, u64 trace_nr) 34400447ccdSAdrian Hunter { 345256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 346bd8e68acSAdrian Hunter 34700447ccdSAdrian Hunter if (!thread) 34800447ccdSAdrian Hunter return -EINVAL; 34900447ccdSAdrian Hunter 350bd8e68acSAdrian Hunter if (!ts) { 351256d92bcSAdrian Hunter ts = thread_stack__new(thread, cpu, NULL); 352bd8e68acSAdrian Hunter if (!ts) { 35300447ccdSAdrian Hunter pr_warning("Out of memory: no thread stack\n"); 35400447ccdSAdrian Hunter return -ENOMEM; 35500447ccdSAdrian Hunter } 356bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 35700447ccdSAdrian Hunter } 35800447ccdSAdrian Hunter 35900447ccdSAdrian Hunter /* 36000447ccdSAdrian Hunter * When the trace is discontinuous, the trace_nr changes. In that case 36100447ccdSAdrian Hunter * the stack might be completely invalid. Better to report nothing than 36292a9e4f7SAdrian Hunter * to report something misleading, so flush the stack. 36300447ccdSAdrian Hunter */ 364bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 365bd8e68acSAdrian Hunter if (ts->trace_nr) 366bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 367bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 36800447ccdSAdrian Hunter } 36900447ccdSAdrian Hunter 37092a9e4f7SAdrian Hunter /* Stop here if thread_stack__process() is in use */ 371bd8e68acSAdrian Hunter if (ts->crp) 37292a9e4f7SAdrian Hunter return 0; 37392a9e4f7SAdrian Hunter 37400447ccdSAdrian Hunter if (flags & PERF_IP_FLAG_CALL) { 37500447ccdSAdrian Hunter u64 ret_addr; 37600447ccdSAdrian Hunter 37700447ccdSAdrian Hunter if (!to_ip) 37800447ccdSAdrian Hunter return 0; 37900447ccdSAdrian Hunter ret_addr = from_ip + insn_len; 38000447ccdSAdrian Hunter if (ret_addr == to_ip) 38100447ccdSAdrian Hunter return 0; /* Zero-length calls are excluded */ 382bd8e68acSAdrian Hunter return thread_stack__push(ts, ret_addr, 3834d60e5e3SAdrian Hunter flags & PERF_IP_FLAG_TRACE_END); 3844d60e5e3SAdrian Hunter } else if (flags & PERF_IP_FLAG_TRACE_BEGIN) { 3854d60e5e3SAdrian Hunter /* 3864d60e5e3SAdrian Hunter * If the caller did not change the trace number (which would 3874d60e5e3SAdrian Hunter * have flushed the stack) then try to make sense of the stack. 3884d60e5e3SAdrian Hunter * Possibly, tracing began after returning to the current 3894d60e5e3SAdrian Hunter * address, so try to pop that. Also, do not expect a call made 3904d60e5e3SAdrian Hunter * when the trace ended, to return, so pop that. 3914d60e5e3SAdrian Hunter */ 392bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 393bd8e68acSAdrian Hunter thread_stack__pop_trace_end(ts); 3944d60e5e3SAdrian Hunter } else if ((flags & PERF_IP_FLAG_RETURN) && from_ip) { 395bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 39600447ccdSAdrian Hunter } 39700447ccdSAdrian Hunter 39800447ccdSAdrian Hunter return 0; 39900447ccdSAdrian Hunter } 40000447ccdSAdrian Hunter 401256d92bcSAdrian Hunter void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr) 40292a9e4f7SAdrian Hunter { 403256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 404bd8e68acSAdrian Hunter 405bd8e68acSAdrian Hunter if (!ts) 40692a9e4f7SAdrian Hunter return; 40792a9e4f7SAdrian Hunter 408bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 409bd8e68acSAdrian Hunter if (ts->trace_nr) 410bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 411bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 41292a9e4f7SAdrian Hunter } 41392a9e4f7SAdrian Hunter } 41492a9e4f7SAdrian Hunter 415f6060ac6SAdrian Hunter static void __thread_stack__free(struct thread *thread, struct thread_stack *ts) 416f6060ac6SAdrian Hunter { 417f6060ac6SAdrian Hunter __thread_stack__flush(thread, ts); 418f6060ac6SAdrian Hunter zfree(&ts->stack); 419f6060ac6SAdrian Hunter } 420f6060ac6SAdrian Hunter 421f6060ac6SAdrian Hunter static void thread_stack__reset(struct thread *thread, struct thread_stack *ts) 422f6060ac6SAdrian Hunter { 423f6060ac6SAdrian Hunter unsigned int arr_sz = ts->arr_sz; 424f6060ac6SAdrian Hunter 425f6060ac6SAdrian Hunter __thread_stack__free(thread, ts); 426f6060ac6SAdrian Hunter memset(ts, 0, sizeof(*ts)); 427f6060ac6SAdrian Hunter ts->arr_sz = arr_sz; 428f6060ac6SAdrian Hunter } 429f6060ac6SAdrian Hunter 43000447ccdSAdrian Hunter void thread_stack__free(struct thread *thread) 43100447ccdSAdrian Hunter { 432bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 433f6060ac6SAdrian Hunter unsigned int pos; 434bd8e68acSAdrian Hunter 435bd8e68acSAdrian Hunter if (ts) { 436f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) 437f6060ac6SAdrian Hunter __thread_stack__free(thread, ts + pos); 43800447ccdSAdrian Hunter zfree(&thread->ts); 43900447ccdSAdrian Hunter } 44000447ccdSAdrian Hunter } 44100447ccdSAdrian Hunter 44224248306SAdrian Hunter static inline u64 callchain_context(u64 ip, u64 kernel_start) 44300447ccdSAdrian Hunter { 44424248306SAdrian Hunter return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL; 44524248306SAdrian Hunter } 44600447ccdSAdrian Hunter 447256d92bcSAdrian Hunter void thread_stack__sample(struct thread *thread, int cpu, 448256d92bcSAdrian Hunter struct ip_callchain *chain, 44924248306SAdrian Hunter size_t sz, u64 ip, u64 kernel_start) 45024248306SAdrian Hunter { 451256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 45224248306SAdrian Hunter u64 context = callchain_context(ip, kernel_start); 45324248306SAdrian Hunter u64 last_context; 45424248306SAdrian Hunter size_t i, j; 45500447ccdSAdrian Hunter 45624248306SAdrian Hunter if (sz < 2) { 45724248306SAdrian Hunter chain->nr = 0; 45824248306SAdrian Hunter return; 45924248306SAdrian Hunter } 46000447ccdSAdrian Hunter 46124248306SAdrian Hunter chain->ips[0] = context; 46224248306SAdrian Hunter chain->ips[1] = ip; 46324248306SAdrian Hunter 464bd8e68acSAdrian Hunter if (!ts) { 46524248306SAdrian Hunter chain->nr = 2; 46624248306SAdrian Hunter return; 46724248306SAdrian Hunter } 46824248306SAdrian Hunter 46924248306SAdrian Hunter last_context = context; 47024248306SAdrian Hunter 471bd8e68acSAdrian Hunter for (i = 2, j = 1; i < sz && j <= ts->cnt; i++, j++) { 472bd8e68acSAdrian Hunter ip = ts->stack[ts->cnt - j].ret_addr; 47324248306SAdrian Hunter context = callchain_context(ip, kernel_start); 47424248306SAdrian Hunter if (context != last_context) { 47524248306SAdrian Hunter if (i >= sz - 1) 47624248306SAdrian Hunter break; 47724248306SAdrian Hunter chain->ips[i++] = context; 47824248306SAdrian Hunter last_context = context; 47924248306SAdrian Hunter } 48024248306SAdrian Hunter chain->ips[i] = ip; 48124248306SAdrian Hunter } 48224248306SAdrian Hunter 48324248306SAdrian Hunter chain->nr = i; 48400447ccdSAdrian Hunter } 48592a9e4f7SAdrian Hunter 48692a9e4f7SAdrian Hunter struct call_return_processor * 48792a9e4f7SAdrian Hunter call_return_processor__new(int (*process)(struct call_return *cr, void *data), 48892a9e4f7SAdrian Hunter void *data) 48992a9e4f7SAdrian Hunter { 49092a9e4f7SAdrian Hunter struct call_return_processor *crp; 49192a9e4f7SAdrian Hunter 49292a9e4f7SAdrian Hunter crp = zalloc(sizeof(struct call_return_processor)); 49392a9e4f7SAdrian Hunter if (!crp) 49492a9e4f7SAdrian Hunter return NULL; 49592a9e4f7SAdrian Hunter crp->cpr = call_path_root__new(); 49692a9e4f7SAdrian Hunter if (!crp->cpr) 49792a9e4f7SAdrian Hunter goto out_free; 49892a9e4f7SAdrian Hunter crp->process = process; 49992a9e4f7SAdrian Hunter crp->data = data; 50092a9e4f7SAdrian Hunter return crp; 50192a9e4f7SAdrian Hunter 50292a9e4f7SAdrian Hunter out_free: 50392a9e4f7SAdrian Hunter free(crp); 50492a9e4f7SAdrian Hunter return NULL; 50592a9e4f7SAdrian Hunter } 50692a9e4f7SAdrian Hunter 50792a9e4f7SAdrian Hunter void call_return_processor__free(struct call_return_processor *crp) 50892a9e4f7SAdrian Hunter { 50992a9e4f7SAdrian Hunter if (crp) { 51092a9e4f7SAdrian Hunter call_path_root__free(crp->cpr); 51192a9e4f7SAdrian Hunter free(crp); 51292a9e4f7SAdrian Hunter } 51392a9e4f7SAdrian Hunter } 51492a9e4f7SAdrian Hunter 51592a9e4f7SAdrian Hunter static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, 51692a9e4f7SAdrian Hunter u64 timestamp, u64 ref, struct call_path *cp, 5172dcde4e1SAdrian Hunter bool no_call, bool trace_end) 51892a9e4f7SAdrian Hunter { 51992a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 52092a9e4f7SAdrian Hunter int err; 52192a9e4f7SAdrian Hunter 522e7a3a055SAdrian Hunter if (!cp) 523e7a3a055SAdrian Hunter return -ENOMEM; 524e7a3a055SAdrian Hunter 52592a9e4f7SAdrian Hunter if (ts->cnt == ts->sz) { 52692a9e4f7SAdrian Hunter err = thread_stack__grow(ts); 52792a9e4f7SAdrian Hunter if (err) 52892a9e4f7SAdrian Hunter return err; 52992a9e4f7SAdrian Hunter } 53092a9e4f7SAdrian Hunter 53192a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt++]; 53292a9e4f7SAdrian Hunter tse->ret_addr = ret_addr; 53392a9e4f7SAdrian Hunter tse->timestamp = timestamp; 53492a9e4f7SAdrian Hunter tse->ref = ref; 53592a9e4f7SAdrian Hunter tse->branch_count = ts->branch_count; 53692a9e4f7SAdrian Hunter tse->cp = cp; 53792a9e4f7SAdrian Hunter tse->no_call = no_call; 5382dcde4e1SAdrian Hunter tse->trace_end = trace_end; 539f08046cbSAdrian Hunter tse->non_call = false; 54092a9e4f7SAdrian Hunter 54192a9e4f7SAdrian Hunter return 0; 54292a9e4f7SAdrian Hunter } 54392a9e4f7SAdrian Hunter 54492a9e4f7SAdrian Hunter static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts, 54592a9e4f7SAdrian Hunter u64 ret_addr, u64 timestamp, u64 ref, 54692a9e4f7SAdrian Hunter struct symbol *sym) 54792a9e4f7SAdrian Hunter { 54892a9e4f7SAdrian Hunter int err; 54992a9e4f7SAdrian Hunter 55092a9e4f7SAdrian Hunter if (!ts->cnt) 55192a9e4f7SAdrian Hunter return 1; 55292a9e4f7SAdrian Hunter 55392a9e4f7SAdrian Hunter if (ts->cnt == 1) { 55492a9e4f7SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[0]; 55592a9e4f7SAdrian Hunter 55692a9e4f7SAdrian Hunter if (tse->cp->sym == sym) 55792a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 55892a9e4f7SAdrian Hunter timestamp, ref, false); 55992a9e4f7SAdrian Hunter } 56092a9e4f7SAdrian Hunter 561f08046cbSAdrian Hunter if (ts->stack[ts->cnt - 1].ret_addr == ret_addr && 562f08046cbSAdrian Hunter !ts->stack[ts->cnt - 1].non_call) { 56392a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 56492a9e4f7SAdrian Hunter timestamp, ref, false); 56592a9e4f7SAdrian Hunter } else { 56692a9e4f7SAdrian Hunter size_t i = ts->cnt - 1; 56792a9e4f7SAdrian Hunter 56892a9e4f7SAdrian Hunter while (i--) { 569f08046cbSAdrian Hunter if (ts->stack[i].ret_addr != ret_addr || 570f08046cbSAdrian Hunter ts->stack[i].non_call) 57192a9e4f7SAdrian Hunter continue; 57292a9e4f7SAdrian Hunter i += 1; 57392a9e4f7SAdrian Hunter while (ts->cnt > i) { 57492a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, 57592a9e4f7SAdrian Hunter --ts->cnt, 57692a9e4f7SAdrian Hunter timestamp, ref, 57792a9e4f7SAdrian Hunter true); 57892a9e4f7SAdrian Hunter if (err) 57992a9e4f7SAdrian Hunter return err; 58092a9e4f7SAdrian Hunter } 58192a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 58292a9e4f7SAdrian Hunter timestamp, ref, false); 58392a9e4f7SAdrian Hunter } 58492a9e4f7SAdrian Hunter } 58592a9e4f7SAdrian Hunter 58692a9e4f7SAdrian Hunter return 1; 58792a9e4f7SAdrian Hunter } 58892a9e4f7SAdrian Hunter 589e0b89511SAdrian Hunter static int thread_stack__bottom(struct thread_stack *ts, 59092a9e4f7SAdrian Hunter struct perf_sample *sample, 59192a9e4f7SAdrian Hunter struct addr_location *from_al, 59292a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 59392a9e4f7SAdrian Hunter { 59492a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 59592a9e4f7SAdrian Hunter struct call_path *cp; 59692a9e4f7SAdrian Hunter struct symbol *sym; 59792a9e4f7SAdrian Hunter u64 ip; 59892a9e4f7SAdrian Hunter 59992a9e4f7SAdrian Hunter if (sample->ip) { 60092a9e4f7SAdrian Hunter ip = sample->ip; 60192a9e4f7SAdrian Hunter sym = from_al->sym; 60292a9e4f7SAdrian Hunter } else if (sample->addr) { 60392a9e4f7SAdrian Hunter ip = sample->addr; 60492a9e4f7SAdrian Hunter sym = to_al->sym; 60592a9e4f7SAdrian Hunter } else { 60692a9e4f7SAdrian Hunter return 0; 60792a9e4f7SAdrian Hunter } 60892a9e4f7SAdrian Hunter 60992a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, &cpr->call_path, sym, ip, 61092a9e4f7SAdrian Hunter ts->kernel_start); 61192a9e4f7SAdrian Hunter 612e0b89511SAdrian Hunter return thread_stack__push_cp(ts, ip, sample->time, ref, cp, 6132dcde4e1SAdrian Hunter true, false); 61492a9e4f7SAdrian Hunter } 61592a9e4f7SAdrian Hunter 61692a9e4f7SAdrian Hunter static int thread_stack__no_call_return(struct thread *thread, 61792a9e4f7SAdrian Hunter struct thread_stack *ts, 61892a9e4f7SAdrian Hunter struct perf_sample *sample, 61992a9e4f7SAdrian Hunter struct addr_location *from_al, 62092a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 62192a9e4f7SAdrian Hunter { 62292a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 62390c2cda7SAdrian Hunter struct call_path *root = &cpr->call_path; 62490c2cda7SAdrian Hunter struct symbol *fsym = from_al->sym; 62590c2cda7SAdrian Hunter struct symbol *tsym = to_al->sym; 62692a9e4f7SAdrian Hunter struct call_path *cp, *parent; 62792a9e4f7SAdrian Hunter u64 ks = ts->kernel_start; 62890c2cda7SAdrian Hunter u64 addr = sample->addr; 62990c2cda7SAdrian Hunter u64 tm = sample->time; 63090c2cda7SAdrian Hunter u64 ip = sample->ip; 63192a9e4f7SAdrian Hunter int err; 63292a9e4f7SAdrian Hunter 63390c2cda7SAdrian Hunter if (ip >= ks && addr < ks) { 63492a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 63592a9e4f7SAdrian Hunter while (thread_stack__in_kernel(ts)) { 63692a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 63790c2cda7SAdrian Hunter tm, ref, true); 63892a9e4f7SAdrian Hunter if (err) 63992a9e4f7SAdrian Hunter return err; 64092a9e4f7SAdrian Hunter } 64192a9e4f7SAdrian Hunter 64292a9e4f7SAdrian Hunter /* If the stack is empty, push the userspace address */ 64392a9e4f7SAdrian Hunter if (!ts->cnt) { 64490c2cda7SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 64590c2cda7SAdrian Hunter return thread_stack__push_cp(ts, 0, tm, ref, cp, true, 64690c2cda7SAdrian Hunter false); 64792a9e4f7SAdrian Hunter } 64890c2cda7SAdrian Hunter } else if (thread_stack__in_kernel(ts) && ip < ks) { 64992a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 65092a9e4f7SAdrian Hunter while (thread_stack__in_kernel(ts)) { 65192a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 65290c2cda7SAdrian Hunter tm, ref, true); 65392a9e4f7SAdrian Hunter if (err) 65492a9e4f7SAdrian Hunter return err; 65592a9e4f7SAdrian Hunter } 65692a9e4f7SAdrian Hunter } 65792a9e4f7SAdrian Hunter 65892a9e4f7SAdrian Hunter if (ts->cnt) 65992a9e4f7SAdrian Hunter parent = ts->stack[ts->cnt - 1].cp; 66092a9e4f7SAdrian Hunter else 66190c2cda7SAdrian Hunter parent = root; 66292a9e4f7SAdrian Hunter 6631f35cd65SAdrian Hunter if (parent->sym == from_al->sym) { 6641f35cd65SAdrian Hunter /* 6651f35cd65SAdrian Hunter * At the bottom of the stack, assume the missing 'call' was 6661f35cd65SAdrian Hunter * before the trace started. So, pop the current symbol and push 6671f35cd65SAdrian Hunter * the 'to' symbol. 6681f35cd65SAdrian Hunter */ 6691f35cd65SAdrian Hunter if (ts->cnt == 1) { 6701f35cd65SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 6711f35cd65SAdrian Hunter tm, ref, false); 6721f35cd65SAdrian Hunter if (err) 6731f35cd65SAdrian Hunter return err; 6741f35cd65SAdrian Hunter } 6751f35cd65SAdrian Hunter 6761f35cd65SAdrian Hunter if (!ts->cnt) { 6771f35cd65SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 6781f35cd65SAdrian Hunter 6791f35cd65SAdrian Hunter return thread_stack__push_cp(ts, addr, tm, ref, cp, 6801f35cd65SAdrian Hunter true, false); 6811f35cd65SAdrian Hunter } 6821f35cd65SAdrian Hunter 6831f35cd65SAdrian Hunter /* 6841f35cd65SAdrian Hunter * Otherwise assume the 'return' is being used as a jump (e.g. 6851f35cd65SAdrian Hunter * retpoline) and just push the 'to' symbol. 6861f35cd65SAdrian Hunter */ 6871f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 6881f35cd65SAdrian Hunter 6891f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, 0, tm, ref, cp, true, false); 6901f35cd65SAdrian Hunter if (!err) 6911f35cd65SAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 6921f35cd65SAdrian Hunter 6931f35cd65SAdrian Hunter return err; 6941f35cd65SAdrian Hunter } 6951f35cd65SAdrian Hunter 6961f35cd65SAdrian Hunter /* 6971f35cd65SAdrian Hunter * Assume 'parent' has not yet returned, so push 'to', and then push and 6981f35cd65SAdrian Hunter * pop 'from'. 6991f35cd65SAdrian Hunter */ 7001f35cd65SAdrian Hunter 7011f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 70292a9e4f7SAdrian Hunter 70390c2cda7SAdrian Hunter err = thread_stack__push_cp(ts, addr, tm, ref, cp, true, false); 70492a9e4f7SAdrian Hunter if (err) 70592a9e4f7SAdrian Hunter return err; 70692a9e4f7SAdrian Hunter 7071f35cd65SAdrian Hunter cp = call_path__findnew(cpr, cp, fsym, ip, ks); 7081f35cd65SAdrian Hunter 7091f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, ip, tm, ref, cp, true, false); 7101f35cd65SAdrian Hunter if (err) 7111f35cd65SAdrian Hunter return err; 7121f35cd65SAdrian Hunter 7131f35cd65SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, tm, ref, false); 71492a9e4f7SAdrian Hunter } 71592a9e4f7SAdrian Hunter 71692a9e4f7SAdrian Hunter static int thread_stack__trace_begin(struct thread *thread, 71792a9e4f7SAdrian Hunter struct thread_stack *ts, u64 timestamp, 71892a9e4f7SAdrian Hunter u64 ref) 71992a9e4f7SAdrian Hunter { 72092a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 72192a9e4f7SAdrian Hunter int err; 72292a9e4f7SAdrian Hunter 72392a9e4f7SAdrian Hunter if (!ts->cnt) 72492a9e4f7SAdrian Hunter return 0; 72592a9e4f7SAdrian Hunter 72692a9e4f7SAdrian Hunter /* Pop trace end */ 72792a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt - 1]; 7282dcde4e1SAdrian Hunter if (tse->trace_end) { 72992a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 73092a9e4f7SAdrian Hunter timestamp, ref, false); 73192a9e4f7SAdrian Hunter if (err) 73292a9e4f7SAdrian Hunter return err; 73392a9e4f7SAdrian Hunter } 73492a9e4f7SAdrian Hunter 73592a9e4f7SAdrian Hunter return 0; 73692a9e4f7SAdrian Hunter } 73792a9e4f7SAdrian Hunter 73892a9e4f7SAdrian Hunter static int thread_stack__trace_end(struct thread_stack *ts, 73992a9e4f7SAdrian Hunter struct perf_sample *sample, u64 ref) 74092a9e4f7SAdrian Hunter { 74192a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 74292a9e4f7SAdrian Hunter struct call_path *cp; 74392a9e4f7SAdrian Hunter u64 ret_addr; 74492a9e4f7SAdrian Hunter 74592a9e4f7SAdrian Hunter /* No point having 'trace end' on the bottom of the stack */ 74692a9e4f7SAdrian Hunter if (!ts->cnt || (ts->cnt == 1 && ts->stack[0].ref == ref)) 74792a9e4f7SAdrian Hunter return 0; 74892a9e4f7SAdrian Hunter 74992a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, NULL, 0, 75092a9e4f7SAdrian Hunter ts->kernel_start); 75192a9e4f7SAdrian Hunter 75292a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 75392a9e4f7SAdrian Hunter 75492a9e4f7SAdrian Hunter return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp, 7552dcde4e1SAdrian Hunter false, true); 75692a9e4f7SAdrian Hunter } 75792a9e4f7SAdrian Hunter 7583c0cd952SAdrian Hunter static bool is_x86_retpoline(const char *name) 7593c0cd952SAdrian Hunter { 7603c0cd952SAdrian Hunter const char *p = strstr(name, "__x86_indirect_thunk_"); 7613c0cd952SAdrian Hunter 7623c0cd952SAdrian Hunter return p == name || !strcmp(name, "__indirect_thunk_start"); 7633c0cd952SAdrian Hunter } 7643c0cd952SAdrian Hunter 7653c0cd952SAdrian Hunter /* 7663c0cd952SAdrian Hunter * x86 retpoline functions pollute the call graph. This function removes them. 7673c0cd952SAdrian Hunter * This does not handle function return thunks, nor is there any improvement 7683c0cd952SAdrian Hunter * for the handling of inline thunks or extern thunks. 7693c0cd952SAdrian Hunter */ 7703c0cd952SAdrian Hunter static int thread_stack__x86_retpoline(struct thread_stack *ts, 7713c0cd952SAdrian Hunter struct perf_sample *sample, 7723c0cd952SAdrian Hunter struct addr_location *to_al) 7733c0cd952SAdrian Hunter { 7743c0cd952SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[ts->cnt - 1]; 7753c0cd952SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 7763c0cd952SAdrian Hunter struct symbol *sym = tse->cp->sym; 7773c0cd952SAdrian Hunter struct symbol *tsym = to_al->sym; 7783c0cd952SAdrian Hunter struct call_path *cp; 7793c0cd952SAdrian Hunter 7803c0cd952SAdrian Hunter if (sym && is_x86_retpoline(sym->name)) { 7813c0cd952SAdrian Hunter /* 7823c0cd952SAdrian Hunter * This is a x86 retpoline fn. It pollutes the call graph by 7833c0cd952SAdrian Hunter * showing up everywhere there is an indirect branch, but does 7843c0cd952SAdrian Hunter * not itself mean anything. Here the top-of-stack is removed, 7853c0cd952SAdrian Hunter * by decrementing the stack count, and then further down, the 7863c0cd952SAdrian Hunter * resulting top-of-stack is replaced with the actual target. 7873c0cd952SAdrian Hunter * The result is that the retpoline functions will no longer 7883c0cd952SAdrian Hunter * appear in the call graph. Note this only affects the call 7893c0cd952SAdrian Hunter * graph, since all the original branches are left unchanged. 7903c0cd952SAdrian Hunter */ 7913c0cd952SAdrian Hunter ts->cnt -= 1; 7923c0cd952SAdrian Hunter sym = ts->stack[ts->cnt - 2].cp->sym; 7933c0cd952SAdrian Hunter if (sym && sym == tsym && to_al->addr != tsym->start) { 7943c0cd952SAdrian Hunter /* 7953c0cd952SAdrian Hunter * Target is back to the middle of the symbol we came 7963c0cd952SAdrian Hunter * from so assume it is an indirect jmp and forget it 7973c0cd952SAdrian Hunter * altogether. 7983c0cd952SAdrian Hunter */ 7993c0cd952SAdrian Hunter ts->cnt -= 1; 8003c0cd952SAdrian Hunter return 0; 8013c0cd952SAdrian Hunter } 8023c0cd952SAdrian Hunter } else if (sym && sym == tsym) { 8033c0cd952SAdrian Hunter /* 8043c0cd952SAdrian Hunter * Target is back to the symbol we came from so assume it is an 8053c0cd952SAdrian Hunter * indirect jmp and forget it altogether. 8063c0cd952SAdrian Hunter */ 8073c0cd952SAdrian Hunter ts->cnt -= 1; 8083c0cd952SAdrian Hunter return 0; 8093c0cd952SAdrian Hunter } 8103c0cd952SAdrian Hunter 8113c0cd952SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 2].cp, tsym, 8123c0cd952SAdrian Hunter sample->addr, ts->kernel_start); 8133c0cd952SAdrian Hunter if (!cp) 8143c0cd952SAdrian Hunter return -ENOMEM; 8153c0cd952SAdrian Hunter 8163c0cd952SAdrian Hunter /* Replace the top-of-stack with the actual target */ 8173c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].cp = cp; 8183c0cd952SAdrian Hunter 8193c0cd952SAdrian Hunter return 0; 8203c0cd952SAdrian Hunter } 8213c0cd952SAdrian Hunter 82292a9e4f7SAdrian Hunter int thread_stack__process(struct thread *thread, struct comm *comm, 82392a9e4f7SAdrian Hunter struct perf_sample *sample, 82492a9e4f7SAdrian Hunter struct addr_location *from_al, 82592a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref, 82692a9e4f7SAdrian Hunter struct call_return_processor *crp) 82792a9e4f7SAdrian Hunter { 828256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, sample->cpu); 8293c0cd952SAdrian Hunter enum retpoline_state_t rstate; 83092a9e4f7SAdrian Hunter int err = 0; 83192a9e4f7SAdrian Hunter 83203b32cb2SAdrian Hunter if (ts && !ts->crp) { 83392a9e4f7SAdrian Hunter /* Supersede thread_stack__event() */ 834f6060ac6SAdrian Hunter thread_stack__reset(thread, ts); 83503b32cb2SAdrian Hunter ts = NULL; 83692a9e4f7SAdrian Hunter } 83703b32cb2SAdrian Hunter 83803b32cb2SAdrian Hunter if (!ts) { 839256d92bcSAdrian Hunter ts = thread_stack__new(thread, sample->cpu, crp); 840bd8e68acSAdrian Hunter if (!ts) 84192a9e4f7SAdrian Hunter return -ENOMEM; 84292a9e4f7SAdrian Hunter ts->comm = comm; 84392a9e4f7SAdrian Hunter } 84492a9e4f7SAdrian Hunter 8453c0cd952SAdrian Hunter rstate = ts->rstate; 8463c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED) 8473c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 8483c0cd952SAdrian Hunter 84992a9e4f7SAdrian Hunter /* Flush stack on exec */ 85092a9e4f7SAdrian Hunter if (ts->comm != comm && thread->pid_ == thread->tid) { 851a5499b37SAdrian Hunter err = __thread_stack__flush(thread, ts); 85292a9e4f7SAdrian Hunter if (err) 85392a9e4f7SAdrian Hunter return err; 85492a9e4f7SAdrian Hunter ts->comm = comm; 85592a9e4f7SAdrian Hunter } 85692a9e4f7SAdrian Hunter 85792a9e4f7SAdrian Hunter /* If the stack is empty, put the current symbol on the stack */ 85892a9e4f7SAdrian Hunter if (!ts->cnt) { 859e0b89511SAdrian Hunter err = thread_stack__bottom(ts, sample, from_al, to_al, ref); 86092a9e4f7SAdrian Hunter if (err) 86192a9e4f7SAdrian Hunter return err; 86292a9e4f7SAdrian Hunter } 86392a9e4f7SAdrian Hunter 86492a9e4f7SAdrian Hunter ts->branch_count += 1; 86592a9e4f7SAdrian Hunter ts->last_time = sample->time; 86692a9e4f7SAdrian Hunter 86792a9e4f7SAdrian Hunter if (sample->flags & PERF_IP_FLAG_CALL) { 8682dcde4e1SAdrian Hunter bool trace_end = sample->flags & PERF_IP_FLAG_TRACE_END; 86992a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 87092a9e4f7SAdrian Hunter struct call_path *cp; 87192a9e4f7SAdrian Hunter u64 ret_addr; 87292a9e4f7SAdrian Hunter 87392a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 87492a9e4f7SAdrian Hunter return 0; 87592a9e4f7SAdrian Hunter 87692a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 87792a9e4f7SAdrian Hunter if (ret_addr == sample->addr) 87892a9e4f7SAdrian Hunter return 0; /* Zero-length calls are excluded */ 87992a9e4f7SAdrian Hunter 88092a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 88192a9e4f7SAdrian Hunter to_al->sym, sample->addr, 88292a9e4f7SAdrian Hunter ts->kernel_start); 88392a9e4f7SAdrian Hunter err = thread_stack__push_cp(ts, ret_addr, sample->time, ref, 8842dcde4e1SAdrian Hunter cp, false, trace_end); 8853c0cd952SAdrian Hunter 8863c0cd952SAdrian Hunter /* 8873c0cd952SAdrian Hunter * A call to the same symbol but not the start of the symbol, 8883c0cd952SAdrian Hunter * may be the start of a x86 retpoline. 8893c0cd952SAdrian Hunter */ 8903c0cd952SAdrian Hunter if (!err && rstate == X86_RETPOLINE_POSSIBLE && to_al->sym && 8913c0cd952SAdrian Hunter from_al->sym == to_al->sym && 8923c0cd952SAdrian Hunter to_al->addr != to_al->sym->start) 8933c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_DETECTED; 8943c0cd952SAdrian Hunter 89592a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_RETURN) { 89692a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 89792a9e4f7SAdrian Hunter return 0; 89892a9e4f7SAdrian Hunter 8993c0cd952SAdrian Hunter /* x86 retpoline 'return' doesn't match the stack */ 9003c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED && ts->cnt > 2 && 9013c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].ret_addr != sample->addr) 9023c0cd952SAdrian Hunter return thread_stack__x86_retpoline(ts, sample, to_al); 9033c0cd952SAdrian Hunter 90492a9e4f7SAdrian Hunter err = thread_stack__pop_cp(thread, ts, sample->addr, 90592a9e4f7SAdrian Hunter sample->time, ref, from_al->sym); 90692a9e4f7SAdrian Hunter if (err) { 90792a9e4f7SAdrian Hunter if (err < 0) 90892a9e4f7SAdrian Hunter return err; 90992a9e4f7SAdrian Hunter err = thread_stack__no_call_return(thread, ts, sample, 91092a9e4f7SAdrian Hunter from_al, to_al, ref); 91192a9e4f7SAdrian Hunter } 91292a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_BEGIN) { 91392a9e4f7SAdrian Hunter err = thread_stack__trace_begin(thread, ts, sample->time, ref); 91492a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_END) { 91592a9e4f7SAdrian Hunter err = thread_stack__trace_end(ts, sample, ref); 916f08046cbSAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_BRANCH && 917f08046cbSAdrian Hunter from_al->sym != to_al->sym && to_al->sym && 918f08046cbSAdrian Hunter to_al->addr == to_al->sym->start) { 919f08046cbSAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 920f08046cbSAdrian Hunter struct call_path *cp; 921f08046cbSAdrian Hunter 922f08046cbSAdrian Hunter /* 923f08046cbSAdrian Hunter * The compiler might optimize a call/ret combination by making 924f08046cbSAdrian Hunter * it a jmp. Make that visible by recording on the stack a 925f08046cbSAdrian Hunter * branch to the start of a different symbol. Note, that means 926f08046cbSAdrian Hunter * when a ret pops the stack, all jmps must be popped off first. 927f08046cbSAdrian Hunter */ 928f08046cbSAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 929f08046cbSAdrian Hunter to_al->sym, sample->addr, 930f08046cbSAdrian Hunter ts->kernel_start); 931f08046cbSAdrian Hunter err = thread_stack__push_cp(ts, 0, sample->time, ref, cp, false, 932f08046cbSAdrian Hunter false); 933f08046cbSAdrian Hunter if (!err) 934f08046cbSAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 93592a9e4f7SAdrian Hunter } 93692a9e4f7SAdrian Hunter 93792a9e4f7SAdrian Hunter return err; 93892a9e4f7SAdrian Hunter } 939e216708dSAdrian Hunter 940256d92bcSAdrian Hunter size_t thread_stack__depth(struct thread *thread, int cpu) 941e216708dSAdrian Hunter { 942256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 943bd8e68acSAdrian Hunter 944bd8e68acSAdrian Hunter if (!ts) 945e216708dSAdrian Hunter return 0; 946bd8e68acSAdrian Hunter return ts->cnt; 947e216708dSAdrian Hunter } 948