12025cf9eSThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only 200447ccdSAdrian Hunter /* 300447ccdSAdrian Hunter * thread-stack.c: Synthesize a thread's stack using call / return events 400447ccdSAdrian Hunter * Copyright (c) 2014, Intel Corporation. 500447ccdSAdrian Hunter */ 600447ccdSAdrian Hunter 792a9e4f7SAdrian Hunter #include <linux/rbtree.h> 892a9e4f7SAdrian Hunter #include <linux/list.h> 9256d92bcSAdrian Hunter #include <linux/log2.h> 10a43783aeSArnaldo Carvalho de Melo #include <errno.h> 1100447ccdSAdrian Hunter #include "thread.h" 1200447ccdSAdrian Hunter #include "event.h" 1392a9e4f7SAdrian Hunter #include "machine.h" 143c0cd952SAdrian Hunter #include "env.h" 1500447ccdSAdrian Hunter #include "util.h" 1600447ccdSAdrian Hunter #include "debug.h" 1792a9e4f7SAdrian Hunter #include "symbol.h" 1892a9e4f7SAdrian Hunter #include "comm.h" 19451db126SChris Phlipot #include "call-path.h" 2000447ccdSAdrian Hunter #include "thread-stack.h" 2100447ccdSAdrian Hunter 2292a9e4f7SAdrian Hunter #define STACK_GROWTH 2048 2392a9e4f7SAdrian Hunter 243c0cd952SAdrian Hunter /* 253c0cd952SAdrian Hunter * State of retpoline detection. 263c0cd952SAdrian Hunter * 273c0cd952SAdrian Hunter * RETPOLINE_NONE: no retpoline detection 283c0cd952SAdrian Hunter * X86_RETPOLINE_POSSIBLE: x86 retpoline possible 293c0cd952SAdrian Hunter * X86_RETPOLINE_DETECTED: x86 retpoline detected 303c0cd952SAdrian Hunter */ 313c0cd952SAdrian Hunter enum retpoline_state_t { 323c0cd952SAdrian Hunter RETPOLINE_NONE, 333c0cd952SAdrian Hunter X86_RETPOLINE_POSSIBLE, 343c0cd952SAdrian Hunter X86_RETPOLINE_DETECTED, 353c0cd952SAdrian Hunter }; 363c0cd952SAdrian Hunter 3792a9e4f7SAdrian Hunter /** 3892a9e4f7SAdrian Hunter * struct thread_stack_entry - thread stack entry. 3992a9e4f7SAdrian Hunter * @ret_addr: return address 4092a9e4f7SAdrian Hunter * @timestamp: timestamp (if known) 4192a9e4f7SAdrian Hunter * @ref: external reference (e.g. db_id of sample) 4292a9e4f7SAdrian Hunter * @branch_count: the branch count when the entry was created 43f435887eSAdrian Hunter * @db_id: id used for db-export 4492a9e4f7SAdrian Hunter * @cp: call path 4592a9e4f7SAdrian Hunter * @no_call: a 'call' was not seen 464d60e5e3SAdrian Hunter * @trace_end: a 'call' but trace ended 47f08046cbSAdrian Hunter * @non_call: a branch but not a 'call' to the start of a different symbol 4892a9e4f7SAdrian Hunter */ 4992a9e4f7SAdrian Hunter struct thread_stack_entry { 5092a9e4f7SAdrian Hunter u64 ret_addr; 5192a9e4f7SAdrian Hunter u64 timestamp; 5292a9e4f7SAdrian Hunter u64 ref; 5392a9e4f7SAdrian Hunter u64 branch_count; 54f435887eSAdrian Hunter u64 db_id; 5592a9e4f7SAdrian Hunter struct call_path *cp; 5692a9e4f7SAdrian Hunter bool no_call; 574d60e5e3SAdrian Hunter bool trace_end; 58f08046cbSAdrian Hunter bool non_call; 5992a9e4f7SAdrian Hunter }; 6092a9e4f7SAdrian Hunter 6192a9e4f7SAdrian Hunter /** 6292a9e4f7SAdrian Hunter * struct thread_stack - thread stack constructed from 'call' and 'return' 6392a9e4f7SAdrian Hunter * branch samples. 6492a9e4f7SAdrian Hunter * @stack: array that holds the stack 6592a9e4f7SAdrian Hunter * @cnt: number of entries in the stack 6692a9e4f7SAdrian Hunter * @sz: current maximum stack size 6792a9e4f7SAdrian Hunter * @trace_nr: current trace number 6892a9e4f7SAdrian Hunter * @branch_count: running branch count 6992a9e4f7SAdrian Hunter * @kernel_start: kernel start address 7092a9e4f7SAdrian Hunter * @last_time: last timestamp 7192a9e4f7SAdrian Hunter * @crp: call/return processor 7292a9e4f7SAdrian Hunter * @comm: current comm 73f6060ac6SAdrian Hunter * @arr_sz: size of array if this is the first element of an array 743c0cd952SAdrian Hunter * @rstate: used to detect retpolines 7592a9e4f7SAdrian Hunter */ 7600447ccdSAdrian Hunter struct thread_stack { 7700447ccdSAdrian Hunter struct thread_stack_entry *stack; 7800447ccdSAdrian Hunter size_t cnt; 7900447ccdSAdrian Hunter size_t sz; 8000447ccdSAdrian Hunter u64 trace_nr; 8192a9e4f7SAdrian Hunter u64 branch_count; 8292a9e4f7SAdrian Hunter u64 kernel_start; 8392a9e4f7SAdrian Hunter u64 last_time; 8492a9e4f7SAdrian Hunter struct call_return_processor *crp; 8592a9e4f7SAdrian Hunter struct comm *comm; 86f6060ac6SAdrian Hunter unsigned int arr_sz; 873c0cd952SAdrian Hunter enum retpoline_state_t rstate; 8800447ccdSAdrian Hunter }; 8900447ccdSAdrian Hunter 90256d92bcSAdrian Hunter /* 91256d92bcSAdrian Hunter * Assume pid == tid == 0 identifies the idle task as defined by 92256d92bcSAdrian Hunter * perf_session__register_idle_thread(). The idle task is really 1 task per cpu, 93256d92bcSAdrian Hunter * and therefore requires a stack for each cpu. 94256d92bcSAdrian Hunter */ 95256d92bcSAdrian Hunter static inline bool thread_stack__per_cpu(struct thread *thread) 96256d92bcSAdrian Hunter { 97256d92bcSAdrian Hunter return !(thread->tid || thread->pid_); 98256d92bcSAdrian Hunter } 99256d92bcSAdrian Hunter 10000447ccdSAdrian Hunter static int thread_stack__grow(struct thread_stack *ts) 10100447ccdSAdrian Hunter { 10200447ccdSAdrian Hunter struct thread_stack_entry *new_stack; 10300447ccdSAdrian Hunter size_t sz, new_sz; 10400447ccdSAdrian Hunter 10500447ccdSAdrian Hunter new_sz = ts->sz + STACK_GROWTH; 10600447ccdSAdrian Hunter sz = new_sz * sizeof(struct thread_stack_entry); 10700447ccdSAdrian Hunter 10800447ccdSAdrian Hunter new_stack = realloc(ts->stack, sz); 10900447ccdSAdrian Hunter if (!new_stack) 11000447ccdSAdrian Hunter return -ENOMEM; 11100447ccdSAdrian Hunter 11200447ccdSAdrian Hunter ts->stack = new_stack; 11300447ccdSAdrian Hunter ts->sz = new_sz; 11400447ccdSAdrian Hunter 11500447ccdSAdrian Hunter return 0; 11600447ccdSAdrian Hunter } 11700447ccdSAdrian Hunter 1182e9e8688SAdrian Hunter static int thread_stack__init(struct thread_stack *ts, struct thread *thread, 1192e9e8688SAdrian Hunter struct call_return_processor *crp) 1202e9e8688SAdrian Hunter { 1212e9e8688SAdrian Hunter int err; 1222e9e8688SAdrian Hunter 1232e9e8688SAdrian Hunter err = thread_stack__grow(ts); 1242e9e8688SAdrian Hunter if (err) 1252e9e8688SAdrian Hunter return err; 1262e9e8688SAdrian Hunter 1273c0cd952SAdrian Hunter if (thread->mg && thread->mg->machine) { 1283c0cd952SAdrian Hunter struct machine *machine = thread->mg->machine; 1293c0cd952SAdrian Hunter const char *arch = perf_env__arch(machine->env); 1303c0cd952SAdrian Hunter 1313c0cd952SAdrian Hunter ts->kernel_start = machine__kernel_start(machine); 1323c0cd952SAdrian Hunter if (!strcmp(arch, "x86")) 1333c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 1343c0cd952SAdrian Hunter } else { 1352e9e8688SAdrian Hunter ts->kernel_start = 1ULL << 63; 1363c0cd952SAdrian Hunter } 1372e9e8688SAdrian Hunter ts->crp = crp; 1382e9e8688SAdrian Hunter 1392e9e8688SAdrian Hunter return 0; 1402e9e8688SAdrian Hunter } 1412e9e8688SAdrian Hunter 142256d92bcSAdrian Hunter static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, 14392a9e4f7SAdrian Hunter struct call_return_processor *crp) 14400447ccdSAdrian Hunter { 145139f42f3SAdrian Hunter struct thread_stack *ts = thread->ts, *new_ts; 146139f42f3SAdrian Hunter unsigned int old_sz = ts ? ts->arr_sz : 0; 147139f42f3SAdrian Hunter unsigned int new_sz = 1; 14800447ccdSAdrian Hunter 149256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0) 150256d92bcSAdrian Hunter new_sz = roundup_pow_of_two(cpu + 1); 151256d92bcSAdrian Hunter 152139f42f3SAdrian Hunter if (!ts || new_sz > old_sz) { 153139f42f3SAdrian Hunter new_ts = calloc(new_sz, sizeof(*ts)); 154139f42f3SAdrian Hunter if (!new_ts) 15500447ccdSAdrian Hunter return NULL; 156139f42f3SAdrian Hunter if (ts) 157139f42f3SAdrian Hunter memcpy(new_ts, ts, old_sz * sizeof(*ts)); 158139f42f3SAdrian Hunter new_ts->arr_sz = new_sz; 159139f42f3SAdrian Hunter zfree(&thread->ts); 160139f42f3SAdrian Hunter thread->ts = new_ts; 161139f42f3SAdrian Hunter ts = new_ts; 16200447ccdSAdrian Hunter } 16300447ccdSAdrian Hunter 164256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread) && cpu > 0 && 165256d92bcSAdrian Hunter (unsigned int)cpu < ts->arr_sz) 166256d92bcSAdrian Hunter ts += cpu; 167256d92bcSAdrian Hunter 168139f42f3SAdrian Hunter if (!ts->stack && 169139f42f3SAdrian Hunter thread_stack__init(ts, thread, crp)) 170139f42f3SAdrian Hunter return NULL; 171bd8e68acSAdrian Hunter 17200447ccdSAdrian Hunter return ts; 17300447ccdSAdrian Hunter } 17400447ccdSAdrian Hunter 175256d92bcSAdrian Hunter static struct thread_stack *thread__cpu_stack(struct thread *thread, int cpu) 176bd8e68acSAdrian Hunter { 177256d92bcSAdrian Hunter struct thread_stack *ts = thread->ts; 178256d92bcSAdrian Hunter 179256d92bcSAdrian Hunter if (cpu < 0) 180256d92bcSAdrian Hunter cpu = 0; 181256d92bcSAdrian Hunter 182256d92bcSAdrian Hunter if (!ts || (unsigned int)cpu >= ts->arr_sz) 183256d92bcSAdrian Hunter return NULL; 184256d92bcSAdrian Hunter 185256d92bcSAdrian Hunter ts += cpu; 186256d92bcSAdrian Hunter 187256d92bcSAdrian Hunter if (!ts->stack) 188256d92bcSAdrian Hunter return NULL; 189256d92bcSAdrian Hunter 190256d92bcSAdrian Hunter return ts; 191256d92bcSAdrian Hunter } 192256d92bcSAdrian Hunter 193256d92bcSAdrian Hunter static inline struct thread_stack *thread__stack(struct thread *thread, 194256d92bcSAdrian Hunter int cpu) 195256d92bcSAdrian Hunter { 196256d92bcSAdrian Hunter if (!thread) 197256d92bcSAdrian Hunter return NULL; 198256d92bcSAdrian Hunter 199256d92bcSAdrian Hunter if (thread_stack__per_cpu(thread)) 200256d92bcSAdrian Hunter return thread__cpu_stack(thread, cpu); 201256d92bcSAdrian Hunter 202256d92bcSAdrian Hunter return thread->ts; 203bd8e68acSAdrian Hunter } 204bd8e68acSAdrian Hunter 2054d60e5e3SAdrian Hunter static int thread_stack__push(struct thread_stack *ts, u64 ret_addr, 2064d60e5e3SAdrian Hunter bool trace_end) 20700447ccdSAdrian Hunter { 20800447ccdSAdrian Hunter int err = 0; 20900447ccdSAdrian Hunter 21000447ccdSAdrian Hunter if (ts->cnt == ts->sz) { 21100447ccdSAdrian Hunter err = thread_stack__grow(ts); 21200447ccdSAdrian Hunter if (err) { 21300447ccdSAdrian Hunter pr_warning("Out of memory: discarding thread stack\n"); 21400447ccdSAdrian Hunter ts->cnt = 0; 21500447ccdSAdrian Hunter } 21600447ccdSAdrian Hunter } 21700447ccdSAdrian Hunter 2184d60e5e3SAdrian Hunter ts->stack[ts->cnt].trace_end = trace_end; 21900447ccdSAdrian Hunter ts->stack[ts->cnt++].ret_addr = ret_addr; 22000447ccdSAdrian Hunter 22100447ccdSAdrian Hunter return err; 22200447ccdSAdrian Hunter } 22300447ccdSAdrian Hunter 22400447ccdSAdrian Hunter static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr) 22500447ccdSAdrian Hunter { 22600447ccdSAdrian Hunter size_t i; 22700447ccdSAdrian Hunter 22800447ccdSAdrian Hunter /* 22900447ccdSAdrian Hunter * In some cases there may be functions which are not seen to return. 23000447ccdSAdrian Hunter * For example when setjmp / longjmp has been used. Or the perf context 23100447ccdSAdrian Hunter * switch in the kernel which doesn't stop and start tracing in exactly 23200447ccdSAdrian Hunter * the same code path. When that happens the return address will be 23300447ccdSAdrian Hunter * further down the stack. If the return address is not found at all, 23400447ccdSAdrian Hunter * we assume the opposite (i.e. this is a return for a call that wasn't 23500447ccdSAdrian Hunter * seen for some reason) and leave the stack alone. 23600447ccdSAdrian Hunter */ 23700447ccdSAdrian Hunter for (i = ts->cnt; i; ) { 23800447ccdSAdrian Hunter if (ts->stack[--i].ret_addr == ret_addr) { 23900447ccdSAdrian Hunter ts->cnt = i; 24000447ccdSAdrian Hunter return; 24100447ccdSAdrian Hunter } 24200447ccdSAdrian Hunter } 24300447ccdSAdrian Hunter } 24400447ccdSAdrian Hunter 2454d60e5e3SAdrian Hunter static void thread_stack__pop_trace_end(struct thread_stack *ts) 2464d60e5e3SAdrian Hunter { 2474d60e5e3SAdrian Hunter size_t i; 2484d60e5e3SAdrian Hunter 2494d60e5e3SAdrian Hunter for (i = ts->cnt; i; ) { 2504d60e5e3SAdrian Hunter if (ts->stack[--i].trace_end) 2514d60e5e3SAdrian Hunter ts->cnt = i; 2524d60e5e3SAdrian Hunter else 2534d60e5e3SAdrian Hunter return; 2544d60e5e3SAdrian Hunter } 2554d60e5e3SAdrian Hunter } 2564d60e5e3SAdrian Hunter 25792a9e4f7SAdrian Hunter static bool thread_stack__in_kernel(struct thread_stack *ts) 25892a9e4f7SAdrian Hunter { 25992a9e4f7SAdrian Hunter if (!ts->cnt) 26092a9e4f7SAdrian Hunter return false; 26192a9e4f7SAdrian Hunter 26292a9e4f7SAdrian Hunter return ts->stack[ts->cnt - 1].cp->in_kernel; 26392a9e4f7SAdrian Hunter } 26492a9e4f7SAdrian Hunter 26592a9e4f7SAdrian Hunter static int thread_stack__call_return(struct thread *thread, 26692a9e4f7SAdrian Hunter struct thread_stack *ts, size_t idx, 26792a9e4f7SAdrian Hunter u64 timestamp, u64 ref, bool no_return) 26892a9e4f7SAdrian Hunter { 26992a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 27092a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 27192a9e4f7SAdrian Hunter struct call_return cr = { 27292a9e4f7SAdrian Hunter .thread = thread, 27392a9e4f7SAdrian Hunter .comm = ts->comm, 27492a9e4f7SAdrian Hunter .db_id = 0, 27592a9e4f7SAdrian Hunter }; 276f435887eSAdrian Hunter u64 *parent_db_id; 27792a9e4f7SAdrian Hunter 27892a9e4f7SAdrian Hunter tse = &ts->stack[idx]; 27992a9e4f7SAdrian Hunter cr.cp = tse->cp; 28092a9e4f7SAdrian Hunter cr.call_time = tse->timestamp; 28192a9e4f7SAdrian Hunter cr.return_time = timestamp; 28292a9e4f7SAdrian Hunter cr.branch_count = ts->branch_count - tse->branch_count; 283f435887eSAdrian Hunter cr.db_id = tse->db_id; 28492a9e4f7SAdrian Hunter cr.call_ref = tse->ref; 28592a9e4f7SAdrian Hunter cr.return_ref = ref; 28692a9e4f7SAdrian Hunter if (tse->no_call) 28792a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_CALL; 28892a9e4f7SAdrian Hunter if (no_return) 28992a9e4f7SAdrian Hunter cr.flags |= CALL_RETURN_NO_RETURN; 290f08046cbSAdrian Hunter if (tse->non_call) 291f08046cbSAdrian Hunter cr.flags |= CALL_RETURN_NON_CALL; 29292a9e4f7SAdrian Hunter 293f435887eSAdrian Hunter /* 294f435887eSAdrian Hunter * The parent db_id must be assigned before exporting the child. Note 295f435887eSAdrian Hunter * it is not possible to export the parent first because its information 296f435887eSAdrian Hunter * is not yet complete because its 'return' has not yet been processed. 297f435887eSAdrian Hunter */ 298f435887eSAdrian Hunter parent_db_id = idx ? &(tse - 1)->db_id : NULL; 299f435887eSAdrian Hunter 300f435887eSAdrian Hunter return crp->process(&cr, parent_db_id, crp->data); 30192a9e4f7SAdrian Hunter } 30292a9e4f7SAdrian Hunter 303a5499b37SAdrian Hunter static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) 30492a9e4f7SAdrian Hunter { 30592a9e4f7SAdrian Hunter struct call_return_processor *crp = ts->crp; 30692a9e4f7SAdrian Hunter int err; 30792a9e4f7SAdrian Hunter 30892a9e4f7SAdrian Hunter if (!crp) { 30992a9e4f7SAdrian Hunter ts->cnt = 0; 31092a9e4f7SAdrian Hunter return 0; 31192a9e4f7SAdrian Hunter } 31292a9e4f7SAdrian Hunter 31392a9e4f7SAdrian Hunter while (ts->cnt) { 31492a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 31592a9e4f7SAdrian Hunter ts->last_time, 0, true); 31692a9e4f7SAdrian Hunter if (err) { 31792a9e4f7SAdrian Hunter pr_err("Error flushing thread stack!\n"); 31892a9e4f7SAdrian Hunter ts->cnt = 0; 31992a9e4f7SAdrian Hunter return err; 32092a9e4f7SAdrian Hunter } 32192a9e4f7SAdrian Hunter } 32292a9e4f7SAdrian Hunter 32392a9e4f7SAdrian Hunter return 0; 32492a9e4f7SAdrian Hunter } 32592a9e4f7SAdrian Hunter 326a5499b37SAdrian Hunter int thread_stack__flush(struct thread *thread) 327a5499b37SAdrian Hunter { 328bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 329f6060ac6SAdrian Hunter unsigned int pos; 330f6060ac6SAdrian Hunter int err = 0; 331bd8e68acSAdrian Hunter 332f6060ac6SAdrian Hunter if (ts) { 333f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) { 334f6060ac6SAdrian Hunter int ret = __thread_stack__flush(thread, ts + pos); 335a5499b37SAdrian Hunter 336f6060ac6SAdrian Hunter if (ret) 337f6060ac6SAdrian Hunter err = ret; 338f6060ac6SAdrian Hunter } 339f6060ac6SAdrian Hunter } 340f6060ac6SAdrian Hunter 341f6060ac6SAdrian Hunter return err; 342a5499b37SAdrian Hunter } 343a5499b37SAdrian Hunter 344256d92bcSAdrian Hunter int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, 34500447ccdSAdrian Hunter u64 to_ip, u16 insn_len, u64 trace_nr) 34600447ccdSAdrian Hunter { 347256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 348bd8e68acSAdrian Hunter 34900447ccdSAdrian Hunter if (!thread) 35000447ccdSAdrian Hunter return -EINVAL; 35100447ccdSAdrian Hunter 352bd8e68acSAdrian Hunter if (!ts) { 353256d92bcSAdrian Hunter ts = thread_stack__new(thread, cpu, NULL); 354bd8e68acSAdrian Hunter if (!ts) { 35500447ccdSAdrian Hunter pr_warning("Out of memory: no thread stack\n"); 35600447ccdSAdrian Hunter return -ENOMEM; 35700447ccdSAdrian Hunter } 358bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 35900447ccdSAdrian Hunter } 36000447ccdSAdrian Hunter 36100447ccdSAdrian Hunter /* 36200447ccdSAdrian Hunter * When the trace is discontinuous, the trace_nr changes. In that case 36300447ccdSAdrian Hunter * the stack might be completely invalid. Better to report nothing than 36492a9e4f7SAdrian Hunter * to report something misleading, so flush the stack. 36500447ccdSAdrian Hunter */ 366bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 367bd8e68acSAdrian Hunter if (ts->trace_nr) 368bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 369bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 37000447ccdSAdrian Hunter } 37100447ccdSAdrian Hunter 37292a9e4f7SAdrian Hunter /* Stop here if thread_stack__process() is in use */ 373bd8e68acSAdrian Hunter if (ts->crp) 37492a9e4f7SAdrian Hunter return 0; 37592a9e4f7SAdrian Hunter 37600447ccdSAdrian Hunter if (flags & PERF_IP_FLAG_CALL) { 37700447ccdSAdrian Hunter u64 ret_addr; 37800447ccdSAdrian Hunter 37900447ccdSAdrian Hunter if (!to_ip) 38000447ccdSAdrian Hunter return 0; 38100447ccdSAdrian Hunter ret_addr = from_ip + insn_len; 38200447ccdSAdrian Hunter if (ret_addr == to_ip) 38300447ccdSAdrian Hunter return 0; /* Zero-length calls are excluded */ 384bd8e68acSAdrian Hunter return thread_stack__push(ts, ret_addr, 3854d60e5e3SAdrian Hunter flags & PERF_IP_FLAG_TRACE_END); 3864d60e5e3SAdrian Hunter } else if (flags & PERF_IP_FLAG_TRACE_BEGIN) { 3874d60e5e3SAdrian Hunter /* 3884d60e5e3SAdrian Hunter * If the caller did not change the trace number (which would 3894d60e5e3SAdrian Hunter * have flushed the stack) then try to make sense of the stack. 3904d60e5e3SAdrian Hunter * Possibly, tracing began after returning to the current 3914d60e5e3SAdrian Hunter * address, so try to pop that. Also, do not expect a call made 3924d60e5e3SAdrian Hunter * when the trace ended, to return, so pop that. 3934d60e5e3SAdrian Hunter */ 394bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 395bd8e68acSAdrian Hunter thread_stack__pop_trace_end(ts); 3964d60e5e3SAdrian Hunter } else if ((flags & PERF_IP_FLAG_RETURN) && from_ip) { 397bd8e68acSAdrian Hunter thread_stack__pop(ts, to_ip); 39800447ccdSAdrian Hunter } 39900447ccdSAdrian Hunter 40000447ccdSAdrian Hunter return 0; 40100447ccdSAdrian Hunter } 40200447ccdSAdrian Hunter 403256d92bcSAdrian Hunter void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr) 40492a9e4f7SAdrian Hunter { 405256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 406bd8e68acSAdrian Hunter 407bd8e68acSAdrian Hunter if (!ts) 40892a9e4f7SAdrian Hunter return; 40992a9e4f7SAdrian Hunter 410bd8e68acSAdrian Hunter if (trace_nr != ts->trace_nr) { 411bd8e68acSAdrian Hunter if (ts->trace_nr) 412bd8e68acSAdrian Hunter __thread_stack__flush(thread, ts); 413bd8e68acSAdrian Hunter ts->trace_nr = trace_nr; 41492a9e4f7SAdrian Hunter } 41592a9e4f7SAdrian Hunter } 41692a9e4f7SAdrian Hunter 417f6060ac6SAdrian Hunter static void __thread_stack__free(struct thread *thread, struct thread_stack *ts) 418f6060ac6SAdrian Hunter { 419f6060ac6SAdrian Hunter __thread_stack__flush(thread, ts); 420f6060ac6SAdrian Hunter zfree(&ts->stack); 421f6060ac6SAdrian Hunter } 422f6060ac6SAdrian Hunter 423f6060ac6SAdrian Hunter static void thread_stack__reset(struct thread *thread, struct thread_stack *ts) 424f6060ac6SAdrian Hunter { 425f6060ac6SAdrian Hunter unsigned int arr_sz = ts->arr_sz; 426f6060ac6SAdrian Hunter 427f6060ac6SAdrian Hunter __thread_stack__free(thread, ts); 428f6060ac6SAdrian Hunter memset(ts, 0, sizeof(*ts)); 429f6060ac6SAdrian Hunter ts->arr_sz = arr_sz; 430f6060ac6SAdrian Hunter } 431f6060ac6SAdrian Hunter 43200447ccdSAdrian Hunter void thread_stack__free(struct thread *thread) 43300447ccdSAdrian Hunter { 434bd8e68acSAdrian Hunter struct thread_stack *ts = thread->ts; 435f6060ac6SAdrian Hunter unsigned int pos; 436bd8e68acSAdrian Hunter 437bd8e68acSAdrian Hunter if (ts) { 438f6060ac6SAdrian Hunter for (pos = 0; pos < ts->arr_sz; pos++) 439f6060ac6SAdrian Hunter __thread_stack__free(thread, ts + pos); 44000447ccdSAdrian Hunter zfree(&thread->ts); 44100447ccdSAdrian Hunter } 44200447ccdSAdrian Hunter } 44300447ccdSAdrian Hunter 44424248306SAdrian Hunter static inline u64 callchain_context(u64 ip, u64 kernel_start) 44500447ccdSAdrian Hunter { 44624248306SAdrian Hunter return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL; 44724248306SAdrian Hunter } 44800447ccdSAdrian Hunter 449256d92bcSAdrian Hunter void thread_stack__sample(struct thread *thread, int cpu, 450256d92bcSAdrian Hunter struct ip_callchain *chain, 45124248306SAdrian Hunter size_t sz, u64 ip, u64 kernel_start) 45224248306SAdrian Hunter { 453256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 45424248306SAdrian Hunter u64 context = callchain_context(ip, kernel_start); 45524248306SAdrian Hunter u64 last_context; 45624248306SAdrian Hunter size_t i, j; 45700447ccdSAdrian Hunter 45824248306SAdrian Hunter if (sz < 2) { 45924248306SAdrian Hunter chain->nr = 0; 46024248306SAdrian Hunter return; 46124248306SAdrian Hunter } 46200447ccdSAdrian Hunter 46324248306SAdrian Hunter chain->ips[0] = context; 46424248306SAdrian Hunter chain->ips[1] = ip; 46524248306SAdrian Hunter 466bd8e68acSAdrian Hunter if (!ts) { 46724248306SAdrian Hunter chain->nr = 2; 46824248306SAdrian Hunter return; 46924248306SAdrian Hunter } 47024248306SAdrian Hunter 47124248306SAdrian Hunter last_context = context; 47224248306SAdrian Hunter 473bd8e68acSAdrian Hunter for (i = 2, j = 1; i < sz && j <= ts->cnt; i++, j++) { 474bd8e68acSAdrian Hunter ip = ts->stack[ts->cnt - j].ret_addr; 47524248306SAdrian Hunter context = callchain_context(ip, kernel_start); 47624248306SAdrian Hunter if (context != last_context) { 47724248306SAdrian Hunter if (i >= sz - 1) 47824248306SAdrian Hunter break; 47924248306SAdrian Hunter chain->ips[i++] = context; 48024248306SAdrian Hunter last_context = context; 48124248306SAdrian Hunter } 48224248306SAdrian Hunter chain->ips[i] = ip; 48324248306SAdrian Hunter } 48424248306SAdrian Hunter 48524248306SAdrian Hunter chain->nr = i; 48600447ccdSAdrian Hunter } 48792a9e4f7SAdrian Hunter 48892a9e4f7SAdrian Hunter struct call_return_processor * 489f435887eSAdrian Hunter call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), 49092a9e4f7SAdrian Hunter void *data) 49192a9e4f7SAdrian Hunter { 49292a9e4f7SAdrian Hunter struct call_return_processor *crp; 49392a9e4f7SAdrian Hunter 49492a9e4f7SAdrian Hunter crp = zalloc(sizeof(struct call_return_processor)); 49592a9e4f7SAdrian Hunter if (!crp) 49692a9e4f7SAdrian Hunter return NULL; 49792a9e4f7SAdrian Hunter crp->cpr = call_path_root__new(); 49892a9e4f7SAdrian Hunter if (!crp->cpr) 49992a9e4f7SAdrian Hunter goto out_free; 50092a9e4f7SAdrian Hunter crp->process = process; 50192a9e4f7SAdrian Hunter crp->data = data; 50292a9e4f7SAdrian Hunter return crp; 50392a9e4f7SAdrian Hunter 50492a9e4f7SAdrian Hunter out_free: 50592a9e4f7SAdrian Hunter free(crp); 50692a9e4f7SAdrian Hunter return NULL; 50792a9e4f7SAdrian Hunter } 50892a9e4f7SAdrian Hunter 50992a9e4f7SAdrian Hunter void call_return_processor__free(struct call_return_processor *crp) 51092a9e4f7SAdrian Hunter { 51192a9e4f7SAdrian Hunter if (crp) { 51292a9e4f7SAdrian Hunter call_path_root__free(crp->cpr); 51392a9e4f7SAdrian Hunter free(crp); 51492a9e4f7SAdrian Hunter } 51592a9e4f7SAdrian Hunter } 51692a9e4f7SAdrian Hunter 51792a9e4f7SAdrian Hunter static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, 51892a9e4f7SAdrian Hunter u64 timestamp, u64 ref, struct call_path *cp, 5192dcde4e1SAdrian Hunter bool no_call, bool trace_end) 52092a9e4f7SAdrian Hunter { 52192a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 52292a9e4f7SAdrian Hunter int err; 52392a9e4f7SAdrian Hunter 524e7a3a055SAdrian Hunter if (!cp) 525e7a3a055SAdrian Hunter return -ENOMEM; 526e7a3a055SAdrian Hunter 52792a9e4f7SAdrian Hunter if (ts->cnt == ts->sz) { 52892a9e4f7SAdrian Hunter err = thread_stack__grow(ts); 52992a9e4f7SAdrian Hunter if (err) 53092a9e4f7SAdrian Hunter return err; 53192a9e4f7SAdrian Hunter } 53292a9e4f7SAdrian Hunter 53392a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt++]; 53492a9e4f7SAdrian Hunter tse->ret_addr = ret_addr; 53592a9e4f7SAdrian Hunter tse->timestamp = timestamp; 53692a9e4f7SAdrian Hunter tse->ref = ref; 53792a9e4f7SAdrian Hunter tse->branch_count = ts->branch_count; 53892a9e4f7SAdrian Hunter tse->cp = cp; 53992a9e4f7SAdrian Hunter tse->no_call = no_call; 5402dcde4e1SAdrian Hunter tse->trace_end = trace_end; 541f08046cbSAdrian Hunter tse->non_call = false; 542f435887eSAdrian Hunter tse->db_id = 0; 54392a9e4f7SAdrian Hunter 54492a9e4f7SAdrian Hunter return 0; 54592a9e4f7SAdrian Hunter } 54692a9e4f7SAdrian Hunter 54792a9e4f7SAdrian Hunter static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts, 54892a9e4f7SAdrian Hunter u64 ret_addr, u64 timestamp, u64 ref, 54992a9e4f7SAdrian Hunter struct symbol *sym) 55092a9e4f7SAdrian Hunter { 55192a9e4f7SAdrian Hunter int err; 55292a9e4f7SAdrian Hunter 55392a9e4f7SAdrian Hunter if (!ts->cnt) 55492a9e4f7SAdrian Hunter return 1; 55592a9e4f7SAdrian Hunter 55692a9e4f7SAdrian Hunter if (ts->cnt == 1) { 55792a9e4f7SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[0]; 55892a9e4f7SAdrian Hunter 55992a9e4f7SAdrian Hunter if (tse->cp->sym == sym) 56092a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 56192a9e4f7SAdrian Hunter timestamp, ref, false); 56292a9e4f7SAdrian Hunter } 56392a9e4f7SAdrian Hunter 564f08046cbSAdrian Hunter if (ts->stack[ts->cnt - 1].ret_addr == ret_addr && 565f08046cbSAdrian Hunter !ts->stack[ts->cnt - 1].non_call) { 56692a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 56792a9e4f7SAdrian Hunter timestamp, ref, false); 56892a9e4f7SAdrian Hunter } else { 56992a9e4f7SAdrian Hunter size_t i = ts->cnt - 1; 57092a9e4f7SAdrian Hunter 57192a9e4f7SAdrian Hunter while (i--) { 572f08046cbSAdrian Hunter if (ts->stack[i].ret_addr != ret_addr || 573f08046cbSAdrian Hunter ts->stack[i].non_call) 57492a9e4f7SAdrian Hunter continue; 57592a9e4f7SAdrian Hunter i += 1; 57692a9e4f7SAdrian Hunter while (ts->cnt > i) { 57792a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, 57892a9e4f7SAdrian Hunter --ts->cnt, 57992a9e4f7SAdrian Hunter timestamp, ref, 58092a9e4f7SAdrian Hunter true); 58192a9e4f7SAdrian Hunter if (err) 58292a9e4f7SAdrian Hunter return err; 58392a9e4f7SAdrian Hunter } 58492a9e4f7SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, 58592a9e4f7SAdrian Hunter timestamp, ref, false); 58692a9e4f7SAdrian Hunter } 58792a9e4f7SAdrian Hunter } 58892a9e4f7SAdrian Hunter 58992a9e4f7SAdrian Hunter return 1; 59092a9e4f7SAdrian Hunter } 59192a9e4f7SAdrian Hunter 592e0b89511SAdrian Hunter static int thread_stack__bottom(struct thread_stack *ts, 59392a9e4f7SAdrian Hunter struct perf_sample *sample, 59492a9e4f7SAdrian Hunter struct addr_location *from_al, 59592a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 59692a9e4f7SAdrian Hunter { 59792a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 59892a9e4f7SAdrian Hunter struct call_path *cp; 59992a9e4f7SAdrian Hunter struct symbol *sym; 60092a9e4f7SAdrian Hunter u64 ip; 60192a9e4f7SAdrian Hunter 60292a9e4f7SAdrian Hunter if (sample->ip) { 60392a9e4f7SAdrian Hunter ip = sample->ip; 60492a9e4f7SAdrian Hunter sym = from_al->sym; 60592a9e4f7SAdrian Hunter } else if (sample->addr) { 60692a9e4f7SAdrian Hunter ip = sample->addr; 60792a9e4f7SAdrian Hunter sym = to_al->sym; 60892a9e4f7SAdrian Hunter } else { 60992a9e4f7SAdrian Hunter return 0; 61092a9e4f7SAdrian Hunter } 61192a9e4f7SAdrian Hunter 61292a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, &cpr->call_path, sym, ip, 61392a9e4f7SAdrian Hunter ts->kernel_start); 61492a9e4f7SAdrian Hunter 615e0b89511SAdrian Hunter return thread_stack__push_cp(ts, ip, sample->time, ref, cp, 6162dcde4e1SAdrian Hunter true, false); 61792a9e4f7SAdrian Hunter } 61892a9e4f7SAdrian Hunter 61992a9e4f7SAdrian Hunter static int thread_stack__no_call_return(struct thread *thread, 62092a9e4f7SAdrian Hunter struct thread_stack *ts, 62192a9e4f7SAdrian Hunter struct perf_sample *sample, 62292a9e4f7SAdrian Hunter struct addr_location *from_al, 62392a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref) 62492a9e4f7SAdrian Hunter { 62592a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 62690c2cda7SAdrian Hunter struct call_path *root = &cpr->call_path; 62790c2cda7SAdrian Hunter struct symbol *fsym = from_al->sym; 62890c2cda7SAdrian Hunter struct symbol *tsym = to_al->sym; 62992a9e4f7SAdrian Hunter struct call_path *cp, *parent; 63092a9e4f7SAdrian Hunter u64 ks = ts->kernel_start; 63190c2cda7SAdrian Hunter u64 addr = sample->addr; 63290c2cda7SAdrian Hunter u64 tm = sample->time; 63390c2cda7SAdrian Hunter u64 ip = sample->ip; 63492a9e4f7SAdrian Hunter int err; 63592a9e4f7SAdrian Hunter 63690c2cda7SAdrian Hunter if (ip >= ks && addr < ks) { 63792a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 63892a9e4f7SAdrian Hunter while (thread_stack__in_kernel(ts)) { 63992a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 64090c2cda7SAdrian Hunter tm, ref, true); 64192a9e4f7SAdrian Hunter if (err) 64292a9e4f7SAdrian Hunter return err; 64392a9e4f7SAdrian Hunter } 64492a9e4f7SAdrian Hunter 64592a9e4f7SAdrian Hunter /* If the stack is empty, push the userspace address */ 64692a9e4f7SAdrian Hunter if (!ts->cnt) { 64790c2cda7SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 64890c2cda7SAdrian Hunter return thread_stack__push_cp(ts, 0, tm, ref, cp, true, 64990c2cda7SAdrian Hunter false); 65092a9e4f7SAdrian Hunter } 65190c2cda7SAdrian Hunter } else if (thread_stack__in_kernel(ts) && ip < ks) { 65292a9e4f7SAdrian Hunter /* Return to userspace, so pop all kernel addresses */ 65392a9e4f7SAdrian Hunter while (thread_stack__in_kernel(ts)) { 65492a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 65590c2cda7SAdrian Hunter tm, ref, true); 65692a9e4f7SAdrian Hunter if (err) 65792a9e4f7SAdrian Hunter return err; 65892a9e4f7SAdrian Hunter } 65992a9e4f7SAdrian Hunter } 66092a9e4f7SAdrian Hunter 66192a9e4f7SAdrian Hunter if (ts->cnt) 66292a9e4f7SAdrian Hunter parent = ts->stack[ts->cnt - 1].cp; 66392a9e4f7SAdrian Hunter else 66490c2cda7SAdrian Hunter parent = root; 66592a9e4f7SAdrian Hunter 6661f35cd65SAdrian Hunter if (parent->sym == from_al->sym) { 6671f35cd65SAdrian Hunter /* 6681f35cd65SAdrian Hunter * At the bottom of the stack, assume the missing 'call' was 6691f35cd65SAdrian Hunter * before the trace started. So, pop the current symbol and push 6701f35cd65SAdrian Hunter * the 'to' symbol. 6711f35cd65SAdrian Hunter */ 6721f35cd65SAdrian Hunter if (ts->cnt == 1) { 6731f35cd65SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 6741f35cd65SAdrian Hunter tm, ref, false); 6751f35cd65SAdrian Hunter if (err) 6761f35cd65SAdrian Hunter return err; 6771f35cd65SAdrian Hunter } 6781f35cd65SAdrian Hunter 6791f35cd65SAdrian Hunter if (!ts->cnt) { 6801f35cd65SAdrian Hunter cp = call_path__findnew(cpr, root, tsym, addr, ks); 6811f35cd65SAdrian Hunter 6821f35cd65SAdrian Hunter return thread_stack__push_cp(ts, addr, tm, ref, cp, 6831f35cd65SAdrian Hunter true, false); 6841f35cd65SAdrian Hunter } 6851f35cd65SAdrian Hunter 6861f35cd65SAdrian Hunter /* 6871f35cd65SAdrian Hunter * Otherwise assume the 'return' is being used as a jump (e.g. 6881f35cd65SAdrian Hunter * retpoline) and just push the 'to' symbol. 6891f35cd65SAdrian Hunter */ 6901f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 6911f35cd65SAdrian Hunter 6921f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, 0, tm, ref, cp, true, false); 6931f35cd65SAdrian Hunter if (!err) 6941f35cd65SAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 6951f35cd65SAdrian Hunter 6961f35cd65SAdrian Hunter return err; 6971f35cd65SAdrian Hunter } 6981f35cd65SAdrian Hunter 6991f35cd65SAdrian Hunter /* 7001f35cd65SAdrian Hunter * Assume 'parent' has not yet returned, so push 'to', and then push and 7011f35cd65SAdrian Hunter * pop 'from'. 7021f35cd65SAdrian Hunter */ 7031f35cd65SAdrian Hunter 7041f35cd65SAdrian Hunter cp = call_path__findnew(cpr, parent, tsym, addr, ks); 70592a9e4f7SAdrian Hunter 70690c2cda7SAdrian Hunter err = thread_stack__push_cp(ts, addr, tm, ref, cp, true, false); 70792a9e4f7SAdrian Hunter if (err) 70892a9e4f7SAdrian Hunter return err; 70992a9e4f7SAdrian Hunter 7101f35cd65SAdrian Hunter cp = call_path__findnew(cpr, cp, fsym, ip, ks); 7111f35cd65SAdrian Hunter 7121f35cd65SAdrian Hunter err = thread_stack__push_cp(ts, ip, tm, ref, cp, true, false); 7131f35cd65SAdrian Hunter if (err) 7141f35cd65SAdrian Hunter return err; 7151f35cd65SAdrian Hunter 7161f35cd65SAdrian Hunter return thread_stack__call_return(thread, ts, --ts->cnt, tm, ref, false); 71792a9e4f7SAdrian Hunter } 71892a9e4f7SAdrian Hunter 71992a9e4f7SAdrian Hunter static int thread_stack__trace_begin(struct thread *thread, 72092a9e4f7SAdrian Hunter struct thread_stack *ts, u64 timestamp, 72192a9e4f7SAdrian Hunter u64 ref) 72292a9e4f7SAdrian Hunter { 72392a9e4f7SAdrian Hunter struct thread_stack_entry *tse; 72492a9e4f7SAdrian Hunter int err; 72592a9e4f7SAdrian Hunter 72692a9e4f7SAdrian Hunter if (!ts->cnt) 72792a9e4f7SAdrian Hunter return 0; 72892a9e4f7SAdrian Hunter 72992a9e4f7SAdrian Hunter /* Pop trace end */ 73092a9e4f7SAdrian Hunter tse = &ts->stack[ts->cnt - 1]; 7312dcde4e1SAdrian Hunter if (tse->trace_end) { 73292a9e4f7SAdrian Hunter err = thread_stack__call_return(thread, ts, --ts->cnt, 73392a9e4f7SAdrian Hunter timestamp, ref, false); 73492a9e4f7SAdrian Hunter if (err) 73592a9e4f7SAdrian Hunter return err; 73692a9e4f7SAdrian Hunter } 73792a9e4f7SAdrian Hunter 73892a9e4f7SAdrian Hunter return 0; 73992a9e4f7SAdrian Hunter } 74092a9e4f7SAdrian Hunter 74192a9e4f7SAdrian Hunter static int thread_stack__trace_end(struct thread_stack *ts, 74292a9e4f7SAdrian Hunter struct perf_sample *sample, u64 ref) 74392a9e4f7SAdrian Hunter { 74492a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 74592a9e4f7SAdrian Hunter struct call_path *cp; 74692a9e4f7SAdrian Hunter u64 ret_addr; 74792a9e4f7SAdrian Hunter 74892a9e4f7SAdrian Hunter /* No point having 'trace end' on the bottom of the stack */ 74992a9e4f7SAdrian Hunter if (!ts->cnt || (ts->cnt == 1 && ts->stack[0].ref == ref)) 75092a9e4f7SAdrian Hunter return 0; 75192a9e4f7SAdrian Hunter 75292a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, NULL, 0, 75392a9e4f7SAdrian Hunter ts->kernel_start); 75492a9e4f7SAdrian Hunter 75592a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 75692a9e4f7SAdrian Hunter 75792a9e4f7SAdrian Hunter return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp, 7582dcde4e1SAdrian Hunter false, true); 75992a9e4f7SAdrian Hunter } 76092a9e4f7SAdrian Hunter 7613c0cd952SAdrian Hunter static bool is_x86_retpoline(const char *name) 7623c0cd952SAdrian Hunter { 7633c0cd952SAdrian Hunter const char *p = strstr(name, "__x86_indirect_thunk_"); 7643c0cd952SAdrian Hunter 7653c0cd952SAdrian Hunter return p == name || !strcmp(name, "__indirect_thunk_start"); 7663c0cd952SAdrian Hunter } 7673c0cd952SAdrian Hunter 7683c0cd952SAdrian Hunter /* 7693c0cd952SAdrian Hunter * x86 retpoline functions pollute the call graph. This function removes them. 7703c0cd952SAdrian Hunter * This does not handle function return thunks, nor is there any improvement 7713c0cd952SAdrian Hunter * for the handling of inline thunks or extern thunks. 7723c0cd952SAdrian Hunter */ 7733c0cd952SAdrian Hunter static int thread_stack__x86_retpoline(struct thread_stack *ts, 7743c0cd952SAdrian Hunter struct perf_sample *sample, 7753c0cd952SAdrian Hunter struct addr_location *to_al) 7763c0cd952SAdrian Hunter { 7773c0cd952SAdrian Hunter struct thread_stack_entry *tse = &ts->stack[ts->cnt - 1]; 7783c0cd952SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 7793c0cd952SAdrian Hunter struct symbol *sym = tse->cp->sym; 7803c0cd952SAdrian Hunter struct symbol *tsym = to_al->sym; 7813c0cd952SAdrian Hunter struct call_path *cp; 7823c0cd952SAdrian Hunter 7833c0cd952SAdrian Hunter if (sym && is_x86_retpoline(sym->name)) { 7843c0cd952SAdrian Hunter /* 7853c0cd952SAdrian Hunter * This is a x86 retpoline fn. It pollutes the call graph by 7863c0cd952SAdrian Hunter * showing up everywhere there is an indirect branch, but does 7873c0cd952SAdrian Hunter * not itself mean anything. Here the top-of-stack is removed, 7883c0cd952SAdrian Hunter * by decrementing the stack count, and then further down, the 7893c0cd952SAdrian Hunter * resulting top-of-stack is replaced with the actual target. 7903c0cd952SAdrian Hunter * The result is that the retpoline functions will no longer 7913c0cd952SAdrian Hunter * appear in the call graph. Note this only affects the call 7923c0cd952SAdrian Hunter * graph, since all the original branches are left unchanged. 7933c0cd952SAdrian Hunter */ 7943c0cd952SAdrian Hunter ts->cnt -= 1; 7953c0cd952SAdrian Hunter sym = ts->stack[ts->cnt - 2].cp->sym; 7963c0cd952SAdrian Hunter if (sym && sym == tsym && to_al->addr != tsym->start) { 7973c0cd952SAdrian Hunter /* 7983c0cd952SAdrian Hunter * Target is back to the middle of the symbol we came 7993c0cd952SAdrian Hunter * from so assume it is an indirect jmp and forget it 8003c0cd952SAdrian Hunter * altogether. 8013c0cd952SAdrian Hunter */ 8023c0cd952SAdrian Hunter ts->cnt -= 1; 8033c0cd952SAdrian Hunter return 0; 8043c0cd952SAdrian Hunter } 8053c0cd952SAdrian Hunter } else if (sym && sym == tsym) { 8063c0cd952SAdrian Hunter /* 8073c0cd952SAdrian Hunter * Target is back to the symbol we came from so assume it is an 8083c0cd952SAdrian Hunter * indirect jmp and forget it altogether. 8093c0cd952SAdrian Hunter */ 8103c0cd952SAdrian Hunter ts->cnt -= 1; 8113c0cd952SAdrian Hunter return 0; 8123c0cd952SAdrian Hunter } 8133c0cd952SAdrian Hunter 8143c0cd952SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 2].cp, tsym, 8153c0cd952SAdrian Hunter sample->addr, ts->kernel_start); 8163c0cd952SAdrian Hunter if (!cp) 8173c0cd952SAdrian Hunter return -ENOMEM; 8183c0cd952SAdrian Hunter 8193c0cd952SAdrian Hunter /* Replace the top-of-stack with the actual target */ 8203c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].cp = cp; 8213c0cd952SAdrian Hunter 8223c0cd952SAdrian Hunter return 0; 8233c0cd952SAdrian Hunter } 8243c0cd952SAdrian Hunter 82592a9e4f7SAdrian Hunter int thread_stack__process(struct thread *thread, struct comm *comm, 82692a9e4f7SAdrian Hunter struct perf_sample *sample, 82792a9e4f7SAdrian Hunter struct addr_location *from_al, 82892a9e4f7SAdrian Hunter struct addr_location *to_al, u64 ref, 82992a9e4f7SAdrian Hunter struct call_return_processor *crp) 83092a9e4f7SAdrian Hunter { 831256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, sample->cpu); 8323c0cd952SAdrian Hunter enum retpoline_state_t rstate; 83392a9e4f7SAdrian Hunter int err = 0; 83492a9e4f7SAdrian Hunter 83503b32cb2SAdrian Hunter if (ts && !ts->crp) { 83692a9e4f7SAdrian Hunter /* Supersede thread_stack__event() */ 837f6060ac6SAdrian Hunter thread_stack__reset(thread, ts); 83803b32cb2SAdrian Hunter ts = NULL; 83992a9e4f7SAdrian Hunter } 84003b32cb2SAdrian Hunter 84103b32cb2SAdrian Hunter if (!ts) { 842256d92bcSAdrian Hunter ts = thread_stack__new(thread, sample->cpu, crp); 843bd8e68acSAdrian Hunter if (!ts) 84492a9e4f7SAdrian Hunter return -ENOMEM; 84592a9e4f7SAdrian Hunter ts->comm = comm; 84692a9e4f7SAdrian Hunter } 84792a9e4f7SAdrian Hunter 8483c0cd952SAdrian Hunter rstate = ts->rstate; 8493c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED) 8503c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_POSSIBLE; 8513c0cd952SAdrian Hunter 85292a9e4f7SAdrian Hunter /* Flush stack on exec */ 85392a9e4f7SAdrian Hunter if (ts->comm != comm && thread->pid_ == thread->tid) { 854a5499b37SAdrian Hunter err = __thread_stack__flush(thread, ts); 85592a9e4f7SAdrian Hunter if (err) 85692a9e4f7SAdrian Hunter return err; 85792a9e4f7SAdrian Hunter ts->comm = comm; 85892a9e4f7SAdrian Hunter } 85992a9e4f7SAdrian Hunter 86092a9e4f7SAdrian Hunter /* If the stack is empty, put the current symbol on the stack */ 86192a9e4f7SAdrian Hunter if (!ts->cnt) { 862e0b89511SAdrian Hunter err = thread_stack__bottom(ts, sample, from_al, to_al, ref); 86392a9e4f7SAdrian Hunter if (err) 86492a9e4f7SAdrian Hunter return err; 86592a9e4f7SAdrian Hunter } 86692a9e4f7SAdrian Hunter 86792a9e4f7SAdrian Hunter ts->branch_count += 1; 86892a9e4f7SAdrian Hunter ts->last_time = sample->time; 86992a9e4f7SAdrian Hunter 87092a9e4f7SAdrian Hunter if (sample->flags & PERF_IP_FLAG_CALL) { 8712dcde4e1SAdrian Hunter bool trace_end = sample->flags & PERF_IP_FLAG_TRACE_END; 87292a9e4f7SAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 87392a9e4f7SAdrian Hunter struct call_path *cp; 87492a9e4f7SAdrian Hunter u64 ret_addr; 87592a9e4f7SAdrian Hunter 87692a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 87792a9e4f7SAdrian Hunter return 0; 87892a9e4f7SAdrian Hunter 87992a9e4f7SAdrian Hunter ret_addr = sample->ip + sample->insn_len; 88092a9e4f7SAdrian Hunter if (ret_addr == sample->addr) 88192a9e4f7SAdrian Hunter return 0; /* Zero-length calls are excluded */ 88292a9e4f7SAdrian Hunter 88392a9e4f7SAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 88492a9e4f7SAdrian Hunter to_al->sym, sample->addr, 88592a9e4f7SAdrian Hunter ts->kernel_start); 88692a9e4f7SAdrian Hunter err = thread_stack__push_cp(ts, ret_addr, sample->time, ref, 8872dcde4e1SAdrian Hunter cp, false, trace_end); 8883c0cd952SAdrian Hunter 8893c0cd952SAdrian Hunter /* 8903c0cd952SAdrian Hunter * A call to the same symbol but not the start of the symbol, 8913c0cd952SAdrian Hunter * may be the start of a x86 retpoline. 8923c0cd952SAdrian Hunter */ 8933c0cd952SAdrian Hunter if (!err && rstate == X86_RETPOLINE_POSSIBLE && to_al->sym && 8943c0cd952SAdrian Hunter from_al->sym == to_al->sym && 8953c0cd952SAdrian Hunter to_al->addr != to_al->sym->start) 8963c0cd952SAdrian Hunter ts->rstate = X86_RETPOLINE_DETECTED; 8973c0cd952SAdrian Hunter 89892a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_RETURN) { 89992a9e4f7SAdrian Hunter if (!sample->ip || !sample->addr) 90092a9e4f7SAdrian Hunter return 0; 90192a9e4f7SAdrian Hunter 9023c0cd952SAdrian Hunter /* x86 retpoline 'return' doesn't match the stack */ 9033c0cd952SAdrian Hunter if (rstate == X86_RETPOLINE_DETECTED && ts->cnt > 2 && 9043c0cd952SAdrian Hunter ts->stack[ts->cnt - 1].ret_addr != sample->addr) 9053c0cd952SAdrian Hunter return thread_stack__x86_retpoline(ts, sample, to_al); 9063c0cd952SAdrian Hunter 90792a9e4f7SAdrian Hunter err = thread_stack__pop_cp(thread, ts, sample->addr, 90892a9e4f7SAdrian Hunter sample->time, ref, from_al->sym); 90992a9e4f7SAdrian Hunter if (err) { 91092a9e4f7SAdrian Hunter if (err < 0) 91192a9e4f7SAdrian Hunter return err; 91292a9e4f7SAdrian Hunter err = thread_stack__no_call_return(thread, ts, sample, 91392a9e4f7SAdrian Hunter from_al, to_al, ref); 91492a9e4f7SAdrian Hunter } 91592a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_BEGIN) { 91692a9e4f7SAdrian Hunter err = thread_stack__trace_begin(thread, ts, sample->time, ref); 91792a9e4f7SAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_TRACE_END) { 91892a9e4f7SAdrian Hunter err = thread_stack__trace_end(ts, sample, ref); 919f08046cbSAdrian Hunter } else if (sample->flags & PERF_IP_FLAG_BRANCH && 920f08046cbSAdrian Hunter from_al->sym != to_al->sym && to_al->sym && 921f08046cbSAdrian Hunter to_al->addr == to_al->sym->start) { 922f08046cbSAdrian Hunter struct call_path_root *cpr = ts->crp->cpr; 923f08046cbSAdrian Hunter struct call_path *cp; 924f08046cbSAdrian Hunter 925f08046cbSAdrian Hunter /* 926f08046cbSAdrian Hunter * The compiler might optimize a call/ret combination by making 927f08046cbSAdrian Hunter * it a jmp. Make that visible by recording on the stack a 928f08046cbSAdrian Hunter * branch to the start of a different symbol. Note, that means 929f08046cbSAdrian Hunter * when a ret pops the stack, all jmps must be popped off first. 930f08046cbSAdrian Hunter */ 931f08046cbSAdrian Hunter cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, 932f08046cbSAdrian Hunter to_al->sym, sample->addr, 933f08046cbSAdrian Hunter ts->kernel_start); 934f08046cbSAdrian Hunter err = thread_stack__push_cp(ts, 0, sample->time, ref, cp, false, 935f08046cbSAdrian Hunter false); 936f08046cbSAdrian Hunter if (!err) 937f08046cbSAdrian Hunter ts->stack[ts->cnt - 1].non_call = true; 93892a9e4f7SAdrian Hunter } 93992a9e4f7SAdrian Hunter 94092a9e4f7SAdrian Hunter return err; 94192a9e4f7SAdrian Hunter } 942e216708dSAdrian Hunter 943256d92bcSAdrian Hunter size_t thread_stack__depth(struct thread *thread, int cpu) 944e216708dSAdrian Hunter { 945256d92bcSAdrian Hunter struct thread_stack *ts = thread__stack(thread, cpu); 946bd8e68acSAdrian Hunter 947bd8e68acSAdrian Hunter if (!ts) 948e216708dSAdrian Hunter return 0; 949bd8e68acSAdrian Hunter return ts->cnt; 950e216708dSAdrian Hunter } 951