diff options
Diffstat (limited to 'tools/perf/util/thread-stack.c')
| -rw-r--r-- | tools/perf/util/thread-stack.c | 615 |
1 files changed, 537 insertions, 78 deletions
diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c index d52f27f373ce..c6a0a27b12c2 100644 --- a/tools/perf/util/thread-stack.c +++ b/tools/perf/util/thread-stack.c @@ -1,26 +1,20 @@ +// SPDX-License-Identifier: GPL-2.0-only /* * thread-stack.c: Synthesize a thread's stack using call / return events * Copyright (c) 2014, Intel Corporation. - * - * This program is free software; you can redistribute it and/or modify it - * under the terms and conditions of the GNU General Public License, - * version 2, as published by the Free Software Foundation. - * - * This program is distributed in the hope it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for - * more details. - * */ #include <linux/rbtree.h> #include <linux/list.h> #include <linux/log2.h> +#include <linux/zalloc.h> #include <errno.h> +#include <stdlib.h> +#include <string.h> #include "thread.h" #include "event.h" #include "machine.h" -#include "util.h" +#include "env.h" #include "debug.h" #include "symbol.h" #include "comm.h" @@ -29,24 +23,45 @@ #define STACK_GROWTH 2048 +/* + * State of retpoline detection. + * + * RETPOLINE_NONE: no retpoline detection + * X86_RETPOLINE_POSSIBLE: x86 retpoline possible + * X86_RETPOLINE_DETECTED: x86 retpoline detected + */ +enum retpoline_state_t { + RETPOLINE_NONE, + X86_RETPOLINE_POSSIBLE, + X86_RETPOLINE_DETECTED, +}; + /** * struct thread_stack_entry - thread stack entry. * @ret_addr: return address * @timestamp: timestamp (if known) * @ref: external reference (e.g. db_id of sample) * @branch_count: the branch count when the entry was created + * @insn_count: the instruction count when the entry was created + * @cyc_count the cycle count when the entry was created + * @db_id: id used for db-export * @cp: call path * @no_call: a 'call' was not seen * @trace_end: a 'call' but trace ended + * @non_call: a branch but not a 'call' to the start of a different symbol */ struct thread_stack_entry { u64 ret_addr; u64 timestamp; u64 ref; u64 branch_count; + u64 insn_count; + u64 cyc_count; + u64 db_id; struct call_path *cp; bool no_call; bool trace_end; + bool non_call; }; /** @@ -57,11 +72,18 @@ struct thread_stack_entry { * @sz: current maximum stack size * @trace_nr: current trace number * @branch_count: running branch count + * @insn_count: running instruction count + * @cyc_count running cycle count * @kernel_start: kernel start address * @last_time: last timestamp * @crp: call/return processor * @comm: current comm * @arr_sz: size of array if this is the first element of an array + * @rstate: used to detect retpolines + * @br_stack_rb: branch stack (ring buffer) + * @br_stack_sz: maximum branch stack size + * @br_stack_pos: current position in @br_stack_rb + * @mispred_all: mark all branches as mispredicted */ struct thread_stack { struct thread_stack_entry *stack; @@ -69,11 +91,18 @@ struct thread_stack { size_t sz; u64 trace_nr; u64 branch_count; + u64 insn_count; + u64 cyc_count; u64 kernel_start; u64 last_time; struct call_return_processor *crp; struct comm *comm; unsigned int arr_sz; + enum retpoline_state_t rstate; + struct branch_stack *br_stack_rb; + unsigned int br_stack_sz; + unsigned int br_stack_pos; + bool mispred_all; }; /* @@ -83,7 +112,7 @@ struct thread_stack { */ static inline bool thread_stack__per_cpu(struct thread *thread) { - return !(thread->tid || thread->pid_); + return !(thread__tid(thread) || thread__pid(thread)); } static int thread_stack__grow(struct thread_stack *ts) @@ -105,27 +134,48 @@ static int thread_stack__grow(struct thread_stack *ts) } static int thread_stack__init(struct thread_stack *ts, struct thread *thread, - struct call_return_processor *crp) + struct call_return_processor *crp, + bool callstack, unsigned int br_stack_sz) { int err; - err = thread_stack__grow(ts); - if (err) - return err; + if (callstack) { + err = thread_stack__grow(ts); + if (err) + return err; + } - if (thread->mg && thread->mg->machine) - ts->kernel_start = machine__kernel_start(thread->mg->machine); - else + if (br_stack_sz) { + size_t sz = sizeof(struct branch_stack); + + sz += br_stack_sz * sizeof(struct branch_entry); + ts->br_stack_rb = zalloc(sz); + if (!ts->br_stack_rb) + return -ENOMEM; + ts->br_stack_sz = br_stack_sz; + } + + if (thread__maps(thread) && maps__machine(thread__maps(thread))) { + struct machine *machine = maps__machine(thread__maps(thread)); + const char *arch = perf_env__arch(machine->env); + + ts->kernel_start = machine__kernel_start(machine); + if (!strcmp(arch, "x86")) + ts->rstate = X86_RETPOLINE_POSSIBLE; + } else { ts->kernel_start = 1ULL << 63; + } ts->crp = crp; return 0; } static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, - struct call_return_processor *crp) + struct call_return_processor *crp, + bool callstack, + unsigned int br_stack_sz) { - struct thread_stack *ts = thread->ts, *new_ts; + struct thread_stack *ts = thread__ts(thread), *new_ts; unsigned int old_sz = ts ? ts->arr_sz : 0; unsigned int new_sz = 1; @@ -139,8 +189,8 @@ static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, if (ts) memcpy(new_ts, ts, old_sz * sizeof(*ts)); new_ts->arr_sz = new_sz; - zfree(&thread->ts); - thread->ts = new_ts; + free(thread__ts(thread)); + thread__set_ts(thread, new_ts); ts = new_ts; } @@ -149,7 +199,7 @@ static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, ts += cpu; if (!ts->stack && - thread_stack__init(ts, thread, crp)) + thread_stack__init(ts, thread, crp, callstack, br_stack_sz)) return NULL; return ts; @@ -157,7 +207,7 @@ static struct thread_stack *thread_stack__new(struct thread *thread, int cpu, static struct thread_stack *thread__cpu_stack(struct thread *thread, int cpu) { - struct thread_stack *ts = thread->ts; + struct thread_stack *ts = thread__ts(thread); if (cpu < 0) cpu = 0; @@ -182,7 +232,7 @@ static inline struct thread_stack *thread__stack(struct thread *thread, if (thread_stack__per_cpu(thread)) return thread__cpu_stack(thread, cpu); - return thread->ts; + return thread__ts(thread); } static int thread_stack__push(struct thread_stack *ts, u64 ret_addr, @@ -256,20 +306,33 @@ static int thread_stack__call_return(struct thread *thread, .comm = ts->comm, .db_id = 0, }; + u64 *parent_db_id; tse = &ts->stack[idx]; cr.cp = tse->cp; cr.call_time = tse->timestamp; cr.return_time = timestamp; cr.branch_count = ts->branch_count - tse->branch_count; + cr.insn_count = ts->insn_count - tse->insn_count; + cr.cyc_count = ts->cyc_count - tse->cyc_count; + cr.db_id = tse->db_id; cr.call_ref = tse->ref; cr.return_ref = ref; if (tse->no_call) cr.flags |= CALL_RETURN_NO_CALL; if (no_return) cr.flags |= CALL_RETURN_NO_RETURN; + if (tse->non_call) + cr.flags |= CALL_RETURN_NON_CALL; - return crp->process(&cr, crp->data); + /* + * The parent db_id must be assigned before exporting the child. Note + * it is not possible to export the parent first because its information + * is not yet complete because its 'return' has not yet been processed. + */ + parent_db_id = idx ? &(tse - 1)->db_id : NULL; + + return crp->process(&cr, parent_db_id, crp->data); } static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) @@ -279,6 +342,9 @@ static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) if (!crp) { ts->cnt = 0; + ts->br_stack_pos = 0; + if (ts->br_stack_rb) + ts->br_stack_rb->nr = 0; return 0; } @@ -297,7 +363,7 @@ static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts) int thread_stack__flush(struct thread *thread) { - struct thread_stack *ts = thread->ts; + struct thread_stack *ts = thread__ts(thread); unsigned int pos; int err = 0; @@ -313,8 +379,33 @@ int thread_stack__flush(struct thread *thread) return err; } +static void thread_stack__update_br_stack(struct thread_stack *ts, u32 flags, + u64 from_ip, u64 to_ip) +{ + struct branch_stack *bs = ts->br_stack_rb; + struct branch_entry *be; + + if (!ts->br_stack_pos) + ts->br_stack_pos = ts->br_stack_sz; + + ts->br_stack_pos -= 1; + + be = &bs->entries[ts->br_stack_pos]; + be->from = from_ip; + be->to = to_ip; + be->flags.value = 0; + be->flags.abort = !!(flags & PERF_IP_FLAG_TX_ABORT); + be->flags.in_tx = !!(flags & PERF_IP_FLAG_IN_TX); + /* No support for mispredict */ + be->flags.mispred = ts->mispred_all; + + if (bs->nr < ts->br_stack_sz) + bs->nr += 1; +} + int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, - u64 to_ip, u16 insn_len, u64 trace_nr) + u64 to_ip, u16 insn_len, u64 trace_nr, bool callstack, + unsigned int br_stack_sz, bool mispred_all) { struct thread_stack *ts = thread__stack(thread, cpu); @@ -322,12 +413,13 @@ int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, return -EINVAL; if (!ts) { - ts = thread_stack__new(thread, cpu, NULL); + ts = thread_stack__new(thread, cpu, NULL, callstack, br_stack_sz); if (!ts) { pr_warning("Out of memory: no thread stack\n"); return -ENOMEM; } ts->trace_nr = trace_nr; + ts->mispred_all = mispred_all; } /* @@ -341,8 +433,14 @@ int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip, ts->trace_nr = trace_nr; } - /* Stop here if thread_stack__process() is in use */ - if (ts->crp) + if (br_stack_sz) + thread_stack__update_br_stack(ts, flags, from_ip, to_ip); + + /* + * Stop here if thread_stack__process() is in use, or not recording call + * stack. + */ + if (ts->crp || !callstack) return 0; if (flags & PERF_IP_FLAG_CALL) { @@ -390,6 +488,7 @@ static void __thread_stack__free(struct thread *thread, struct thread_stack *ts) { __thread_stack__flush(thread, ts); zfree(&ts->stack); + zfree(&ts->br_stack_rb); } static void thread_stack__reset(struct thread *thread, struct thread_stack *ts) @@ -403,13 +502,14 @@ static void thread_stack__reset(struct thread *thread, struct thread_stack *ts) void thread_stack__free(struct thread *thread) { - struct thread_stack *ts = thread->ts; + struct thread_stack *ts = thread__ts(thread); unsigned int pos; if (ts) { for (pos = 0; pos < ts->arr_sz; pos++) __thread_stack__free(thread, ts + pos); - zfree(&thread->ts); + free(thread__ts(thread)); + thread__set_ts(thread, NULL); } } @@ -457,8 +557,201 @@ void thread_stack__sample(struct thread *thread, int cpu, chain->nr = i; } +/* + * Hardware sample records, created some time after the event occurred, need to + * have subsequent addresses removed from the call chain. + */ +void thread_stack__sample_late(struct thread *thread, int cpu, + struct ip_callchain *chain, size_t sz, + u64 sample_ip, u64 kernel_start) +{ + struct thread_stack *ts = thread__stack(thread, cpu); + u64 sample_context = callchain_context(sample_ip, kernel_start); + u64 last_context, context, ip; + size_t nr = 0, j; + + if (sz < 2) { + chain->nr = 0; + return; + } + + if (!ts) + goto out; + + /* + * When tracing kernel space, kernel addresses occur at the top of the + * call chain after the event occurred but before tracing stopped. + * Skip them. + */ + for (j = 1; j <= ts->cnt; j++) { + ip = ts->stack[ts->cnt - j].ret_addr; + context = callchain_context(ip, kernel_start); + if (context == PERF_CONTEXT_USER || + (context == sample_context && ip == sample_ip)) + break; + } + + last_context = sample_ip; /* Use sample_ip as an invalid context */ + + for (; nr < sz && j <= ts->cnt; nr++, j++) { + ip = ts->stack[ts->cnt - j].ret_addr; + context = callchain_context(ip, kernel_start); + if (context != last_context) { + if (nr >= sz - 1) + break; + chain->ips[nr++] = context; + last_context = context; + } + chain->ips[nr] = ip; + } +out: + if (nr) { + chain->nr = nr; + } else { + chain->ips[0] = sample_context; + chain->ips[1] = sample_ip; + chain->nr = 2; + } +} + +void thread_stack__br_sample(struct thread *thread, int cpu, + struct branch_stack *dst, unsigned int sz) +{ + struct thread_stack *ts = thread__stack(thread, cpu); + const size_t bsz = sizeof(struct branch_entry); + struct branch_stack *src; + struct branch_entry *be; + unsigned int nr; + + dst->nr = 0; + + if (!ts) + return; + + src = ts->br_stack_rb; + if (!src->nr) + return; + + dst->nr = min((unsigned int)src->nr, sz); + + be = &dst->entries[0]; + nr = min(ts->br_stack_sz - ts->br_stack_pos, (unsigned int)dst->nr); + memcpy(be, &src->entries[ts->br_stack_pos], bsz * nr); + + if (src->nr >= ts->br_stack_sz) { + sz -= nr; + be = &dst->entries[nr]; + nr = min(ts->br_stack_pos, sz); + memcpy(be, &src->entries[0], bsz * ts->br_stack_pos); + } +} + +/* Start of user space branch entries */ +static bool us_start(struct branch_entry *be, u64 kernel_start, bool *start) +{ + if (!*start) + *start = be->to && be->to < kernel_start; + + return *start; +} + +/* + * Start of branch entries after the ip fell in between 2 branches, or user + * space branch entries. + */ +static bool ks_start(struct branch_entry *be, u64 sample_ip, u64 kernel_start, + bool *start, struct branch_entry *nb) +{ + if (!*start) { + *start = (nb && sample_ip >= be->to && sample_ip <= nb->from) || + be->from < kernel_start || + (be->to && be->to < kernel_start); + } + + return *start; +} + +/* + * Hardware sample records, created some time after the event occurred, need to + * have subsequent addresses removed from the branch stack. + */ +void thread_stack__br_sample_late(struct thread *thread, int cpu, + struct branch_stack *dst, unsigned int sz, + u64 ip, u64 kernel_start) +{ + struct thread_stack *ts = thread__stack(thread, cpu); + struct branch_entry *d, *s, *spos, *ssz; + struct branch_stack *src; + unsigned int nr = 0; + bool start = false; + + dst->nr = 0; + + if (!ts) + return; + + src = ts->br_stack_rb; + if (!src->nr) + return; + + spos = &src->entries[ts->br_stack_pos]; + ssz = &src->entries[ts->br_stack_sz]; + + d = &dst->entries[0]; + s = spos; + + if (ip < kernel_start) { + /* + * User space sample: start copying branch entries when the + * branch is in user space. + */ + for (s = spos; s < ssz && nr < sz; s++) { + if (us_start(s, kernel_start, &start)) { + *d++ = *s; + nr += 1; + } + } + + if (src->nr >= ts->br_stack_sz) { + for (s = &src->entries[0]; s < spos && nr < sz; s++) { + if (us_start(s, kernel_start, &start)) { + *d++ = *s; + nr += 1; + } + } + } + } else { + struct branch_entry *nb = NULL; + + /* + * Kernel space sample: start copying branch entries when the ip + * falls in between 2 branches (or the branch is in user space + * because then the start must have been missed). + */ + for (s = spos; s < ssz && nr < sz; s++) { + if (ks_start(s, ip, kernel_start, &start, nb)) { + *d++ = *s; + nr += 1; + } + nb = s; + } + + if (src->nr >= ts->br_stack_sz) { + for (s = &src->entries[0]; s < spos && nr < sz; s++) { + if (ks_start(s, ip, kernel_start, &start, nb)) { + *d++ = *s; + nr += 1; + } + nb = s; + } + } + } + + dst->nr = nr; +} + struct call_return_processor * -call_return_processor__new(int (*process)(struct call_return *cr, void *data), +call_return_processor__new(int (*process)(struct call_return *cr, u64 *parent_db_id, void *data), void *data) { struct call_return_processor *crp; @@ -493,6 +786,9 @@ static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, struct thread_stack_entry *tse; int err; + if (!cp) + return -ENOMEM; + if (ts->cnt == ts->sz) { err = thread_stack__grow(ts); if (err) @@ -504,9 +800,13 @@ static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr, tse->timestamp = timestamp; tse->ref = ref; tse->branch_count = ts->branch_count; + tse->insn_count = ts->insn_count; + tse->cyc_count = ts->cyc_count; tse->cp = cp; tse->no_call = no_call; tse->trace_end = trace_end; + tse->non_call = false; + tse->db_id = 0; return 0; } @@ -528,14 +828,16 @@ static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts, timestamp, ref, false); } - if (ts->stack[ts->cnt - 1].ret_addr == ret_addr) { + if (ts->stack[ts->cnt - 1].ret_addr == ret_addr && + !ts->stack[ts->cnt - 1].non_call) { return thread_stack__call_return(thread, ts, --ts->cnt, timestamp, ref, false); } else { size_t i = ts->cnt - 1; while (i--) { - if (ts->stack[i].ret_addr != ret_addr) + if (ts->stack[i].ret_addr != ret_addr || + ts->stack[i].non_call) continue; i += 1; while (ts->cnt > i) { @@ -576,13 +878,28 @@ static int thread_stack__bottom(struct thread_stack *ts, cp = call_path__findnew(cpr, &cpr->call_path, sym, ip, ts->kernel_start); - if (!cp) - return -ENOMEM; return thread_stack__push_cp(ts, ip, sample->time, ref, cp, true, false); } +static int thread_stack__pop_ks(struct thread *thread, struct thread_stack *ts, + struct perf_sample *sample, u64 ref) +{ + u64 tm = sample->time; + int err; + + /* Return to userspace, so pop all kernel addresses */ + while (thread_stack__in_kernel(ts)) { + err = thread_stack__call_return(thread, ts, --ts->cnt, + tm, ref, true); + if (err) + return err; + } + + return 0; +} + static int thread_stack__no_call_return(struct thread *thread, struct thread_stack *ts, struct perf_sample *sample, @@ -590,59 +907,91 @@ static int thread_stack__no_call_return(struct thread *thread, struct addr_location *to_al, u64 ref) { struct call_path_root *cpr = ts->crp->cpr; + struct call_path *root = &cpr->call_path; + struct symbol *fsym = from_al->sym; + struct symbol *tsym = to_al->sym; struct call_path *cp, *parent; u64 ks = ts->kernel_start; + u64 addr = sample->addr; + u64 tm = sample->time; + u64 ip = sample->ip; int err; - if (sample->ip >= ks && sample->addr < ks) { + if (ip >= ks && addr < ks) { /* Return to userspace, so pop all kernel addresses */ - while (thread_stack__in_kernel(ts)) { - err = thread_stack__call_return(thread, ts, --ts->cnt, - sample->time, ref, - true); - if (err) - return err; - } + err = thread_stack__pop_ks(thread, ts, sample, ref); + if (err) + return err; /* If the stack is empty, push the userspace address */ if (!ts->cnt) { - cp = call_path__findnew(cpr, &cpr->call_path, - to_al->sym, sample->addr, - ts->kernel_start); - if (!cp) - return -ENOMEM; - return thread_stack__push_cp(ts, 0, sample->time, ref, - cp, true, false); + cp = call_path__findnew(cpr, root, tsym, addr, ks); + return thread_stack__push_cp(ts, 0, tm, ref, cp, true, + false); } - } else if (thread_stack__in_kernel(ts) && sample->ip < ks) { + } else if (thread_stack__in_kernel(ts) && ip < ks) { /* Return to userspace, so pop all kernel addresses */ - while (thread_stack__in_kernel(ts)) { + err = thread_stack__pop_ks(thread, ts, sample, ref); + if (err) + return err; + } + + if (ts->cnt) + parent = ts->stack[ts->cnt - 1].cp; + else + parent = root; + + if (parent->sym == from_al->sym) { + /* + * At the bottom of the stack, assume the missing 'call' was + * before the trace started. So, pop the current symbol and push + * the 'to' symbol. + */ + if (ts->cnt == 1) { err = thread_stack__call_return(thread, ts, --ts->cnt, - sample->time, ref, - true); + tm, ref, false); if (err) return err; } + + if (!ts->cnt) { + cp = call_path__findnew(cpr, root, tsym, addr, ks); + + return thread_stack__push_cp(ts, addr, tm, ref, cp, + true, false); + } + + /* + * Otherwise assume the 'return' is being used as a jump (e.g. + * retpoline) and just push the 'to' symbol. + */ + cp = call_path__findnew(cpr, parent, tsym, addr, ks); + + err = thread_stack__push_cp(ts, 0, tm, ref, cp, true, false); + if (!err) + ts->stack[ts->cnt - 1].non_call = true; + + return err; } - if (ts->cnt) - parent = ts->stack[ts->cnt - 1].cp; - else - parent = &cpr->call_path; + /* + * Assume 'parent' has not yet returned, so push 'to', and then push and + * pop 'from'. + */ - /* This 'return' had no 'call', so push and pop top of stack */ - cp = call_path__findnew(cpr, parent, from_al->sym, sample->ip, - ts->kernel_start); - if (!cp) - return -ENOMEM; + cp = call_path__findnew(cpr, parent, tsym, addr, ks); + + err = thread_stack__push_cp(ts, addr, tm, ref, cp, true, false); + if (err) + return err; + + cp = call_path__findnew(cpr, cp, fsym, ip, ks); - err = thread_stack__push_cp(ts, sample->addr, sample->time, ref, cp, - true, false); + err = thread_stack__push_cp(ts, ip, tm, ref, cp, true, false); if (err) return err; - return thread_stack__pop_cp(thread, ts, sample->addr, sample->time, ref, - to_al->sym); + return thread_stack__call_return(thread, ts, --ts->cnt, tm, ref, false); } static int thread_stack__trace_begin(struct thread *thread, @@ -680,8 +1029,6 @@ static int thread_stack__trace_end(struct thread_stack *ts, cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, NULL, 0, ts->kernel_start); - if (!cp) - return -ENOMEM; ret_addr = sample->ip + sample->insn_len; @@ -689,6 +1036,68 @@ static int thread_stack__trace_end(struct thread_stack *ts, false, true); } +static bool is_x86_retpoline(const char *name) +{ + return strstr(name, "__x86_indirect_thunk_") == name; +} + +/* + * x86 retpoline functions pollute the call graph. This function removes them. + * This does not handle function return thunks, nor is there any improvement + * for the handling of inline thunks or extern thunks. + */ +static int thread_stack__x86_retpoline(struct thread_stack *ts, + struct perf_sample *sample, + struct addr_location *to_al) +{ + struct thread_stack_entry *tse = &ts->stack[ts->cnt - 1]; + struct call_path_root *cpr = ts->crp->cpr; + struct symbol *sym = tse->cp->sym; + struct symbol *tsym = to_al->sym; + struct call_path *cp; + + if (sym && is_x86_retpoline(sym->name)) { + /* + * This is a x86 retpoline fn. It pollutes the call graph by + * showing up everywhere there is an indirect branch, but does + * not itself mean anything. Here the top-of-stack is removed, + * by decrementing the stack count, and then further down, the + * resulting top-of-stack is replaced with the actual target. + * The result is that the retpoline functions will no longer + * appear in the call graph. Note this only affects the call + * graph, since all the original branches are left unchanged. + */ + ts->cnt -= 1; + sym = ts->stack[ts->cnt - 2].cp->sym; + if (sym && sym == tsym && to_al->addr != tsym->start) { + /* + * Target is back to the middle of the symbol we came + * from so assume it is an indirect jmp and forget it + * altogether. + */ + ts->cnt -= 1; + return 0; + } + } else if (sym && sym == tsym) { + /* + * Target is back to the symbol we came from so assume it is an + * indirect jmp and forget it altogether. + */ + ts->cnt -= 1; + return 0; + } + + cp = call_path__findnew(cpr, ts->stack[ts->cnt - 2].cp, tsym, + sample->addr, ts->kernel_start); + if (!cp) + return -ENOMEM; + + /* Replace the top-of-stack with the actual target */ + ts->stack[ts->cnt - 1].cp = cp; + + return 0; +} + int thread_stack__process(struct thread *thread, struct comm *comm, struct perf_sample *sample, struct addr_location *from_al, @@ -696,6 +1105,7 @@ int thread_stack__process(struct thread *thread, struct comm *comm, struct call_return_processor *crp) { struct thread_stack *ts = thread__stack(thread, sample->cpu); + enum retpoline_state_t rstate; int err = 0; if (ts && !ts->crp) { @@ -705,14 +1115,18 @@ int thread_stack__process(struct thread *thread, struct comm *comm, } if (!ts) { - ts = thread_stack__new(thread, sample->cpu, crp); + ts = thread_stack__new(thread, sample->cpu, crp, true, 0); if (!ts) return -ENOMEM; ts->comm = comm; } + rstate = ts->rstate; + if (rstate == X86_RETPOLINE_DETECTED) + ts->rstate = X86_RETPOLINE_POSSIBLE; + /* Flush stack on exec */ - if (ts->comm != comm && thread->pid_ == thread->tid) { + if (ts->comm != comm && thread__pid(thread) == thread__tid(thread)) { err = __thread_stack__flush(thread, ts); if (err) return err; @@ -727,6 +1141,8 @@ int thread_stack__process(struct thread *thread, struct comm *comm, } ts->branch_count += 1; + ts->insn_count += sample->insn_cnt; + ts->cyc_count += sample->cyc_cnt; ts->last_time = sample->time; if (sample->flags & PERF_IP_FLAG_CALL) { @@ -745,14 +1161,38 @@ int thread_stack__process(struct thread *thread, struct comm *comm, cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, to_al->sym, sample->addr, ts->kernel_start); - if (!cp) - return -ENOMEM; err = thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp, false, trace_end); + + /* + * A call to the same symbol but not the start of the symbol, + * may be the start of a x86 retpoline. + */ + if (!err && rstate == X86_RETPOLINE_POSSIBLE && to_al->sym && + from_al->sym == to_al->sym && + to_al->addr != to_al->sym->start) + ts->rstate = X86_RETPOLINE_DETECTED; + } else if (sample->flags & PERF_IP_FLAG_RETURN) { - if (!sample->ip || !sample->addr) + if (!sample->addr) { + u32 return_from_kernel = PERF_IP_FLAG_SYSCALLRET | + PERF_IP_FLAG_INTERRUPT; + + if (!(sample->flags & return_from_kernel)) + return 0; + + /* Pop kernel stack */ + return thread_stack__pop_ks(thread, ts, sample, ref); + } + + if (!sample->ip) return 0; + /* x86 retpoline 'return' doesn't match the stack */ + if (rstate == X86_RETPOLINE_DETECTED && ts->cnt > 2 && + ts->stack[ts->cnt - 1].ret_addr != sample->addr) + return thread_stack__x86_retpoline(ts, sample, to_al); + err = thread_stack__pop_cp(thread, ts, sample->addr, sample->time, ref, from_al->sym); if (err) { @@ -765,6 +1205,25 @@ int thread_stack__process(struct thread *thread, struct comm *comm, err = thread_stack__trace_begin(thread, ts, sample->time, ref); } else if (sample->flags & PERF_IP_FLAG_TRACE_END) { err = thread_stack__trace_end(ts, sample, ref); + } else if (sample->flags & PERF_IP_FLAG_BRANCH && + from_al->sym != to_al->sym && to_al->sym && + to_al->addr == to_al->sym->start) { + struct call_path_root *cpr = ts->crp->cpr; + struct call_path *cp; + + /* + * The compiler might optimize a call/ret combination by making + * it a jmp. Make that visible by recording on the stack a + * branch to the start of a different symbol. Note, that means + * when a ret pops the stack, all jmps must be popped off first. + */ + cp = call_path__findnew(cpr, ts->stack[ts->cnt - 1].cp, + to_al->sym, sample->addr, + ts->kernel_start); + err = thread_stack__push_cp(ts, 0, sample->time, ref, cp, false, + false); + if (!err) + ts->stack[ts->cnt - 1].non_call = true; } return err; |