v4.19.13 snapshot.
diff --git a/tools/perf/util/thread-stack.c b/tools/perf/util/thread-stack.c
new file mode 100644
index 0000000..a5669d0
--- /dev/null
+++ b/tools/perf/util/thread-stack.c
@@ -0,0 +1,652 @@
+/*
+ * 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 <errno.h>
+#include "thread.h"
+#include "event.h"
+#include "machine.h"
+#include "util.h"
+#include "debug.h"
+#include "symbol.h"
+#include "comm.h"
+#include "call-path.h"
+#include "thread-stack.h"
+
+#define STACK_GROWTH 2048
+
+/**
+ * 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
+ * @cp: call path
+ * @no_call: a 'call' was not seen
+ */
+struct thread_stack_entry {
+ u64 ret_addr;
+ u64 timestamp;
+ u64 ref;
+ u64 branch_count;
+ struct call_path *cp;
+ bool no_call;
+};
+
+/**
+ * struct thread_stack - thread stack constructed from 'call' and 'return'
+ * branch samples.
+ * @stack: array that holds the stack
+ * @cnt: number of entries in the stack
+ * @sz: current maximum stack size
+ * @trace_nr: current trace number
+ * @branch_count: running branch count
+ * @kernel_start: kernel start address
+ * @last_time: last timestamp
+ * @crp: call/return processor
+ * @comm: current comm
+ */
+struct thread_stack {
+ struct thread_stack_entry *stack;
+ size_t cnt;
+ size_t sz;
+ u64 trace_nr;
+ u64 branch_count;
+ u64 kernel_start;
+ u64 last_time;
+ struct call_return_processor *crp;
+ struct comm *comm;
+};
+
+static int thread_stack__grow(struct thread_stack *ts)
+{
+ struct thread_stack_entry *new_stack;
+ size_t sz, new_sz;
+
+ new_sz = ts->sz + STACK_GROWTH;
+ sz = new_sz * sizeof(struct thread_stack_entry);
+
+ new_stack = realloc(ts->stack, sz);
+ if (!new_stack)
+ return -ENOMEM;
+
+ ts->stack = new_stack;
+ ts->sz = new_sz;
+
+ return 0;
+}
+
+static struct thread_stack *thread_stack__new(struct thread *thread,
+ struct call_return_processor *crp)
+{
+ struct thread_stack *ts;
+
+ ts = zalloc(sizeof(struct thread_stack));
+ if (!ts)
+ return NULL;
+
+ if (thread_stack__grow(ts)) {
+ free(ts);
+ return NULL;
+ }
+
+ if (thread->mg && thread->mg->machine)
+ ts->kernel_start = machine__kernel_start(thread->mg->machine);
+ else
+ ts->kernel_start = 1ULL << 63;
+ ts->crp = crp;
+
+ return ts;
+}
+
+static int thread_stack__push(struct thread_stack *ts, u64 ret_addr)
+{
+ int err = 0;
+
+ if (ts->cnt == ts->sz) {
+ err = thread_stack__grow(ts);
+ if (err) {
+ pr_warning("Out of memory: discarding thread stack\n");
+ ts->cnt = 0;
+ }
+ }
+
+ ts->stack[ts->cnt++].ret_addr = ret_addr;
+
+ return err;
+}
+
+static void thread_stack__pop(struct thread_stack *ts, u64 ret_addr)
+{
+ size_t i;
+
+ /*
+ * In some cases there may be functions which are not seen to return.
+ * For example when setjmp / longjmp has been used. Or the perf context
+ * switch in the kernel which doesn't stop and start tracing in exactly
+ * the same code path. When that happens the return address will be
+ * further down the stack. If the return address is not found at all,
+ * we assume the opposite (i.e. this is a return for a call that wasn't
+ * seen for some reason) and leave the stack alone.
+ */
+ for (i = ts->cnt; i; ) {
+ if (ts->stack[--i].ret_addr == ret_addr) {
+ ts->cnt = i;
+ return;
+ }
+ }
+}
+
+static bool thread_stack__in_kernel(struct thread_stack *ts)
+{
+ if (!ts->cnt)
+ return false;
+
+ return ts->stack[ts->cnt - 1].cp->in_kernel;
+}
+
+static int thread_stack__call_return(struct thread *thread,
+ struct thread_stack *ts, size_t idx,
+ u64 timestamp, u64 ref, bool no_return)
+{
+ struct call_return_processor *crp = ts->crp;
+ struct thread_stack_entry *tse;
+ struct call_return cr = {
+ .thread = thread,
+ .comm = ts->comm,
+ .db_id = 0,
+ };
+
+ 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.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;
+
+ return crp->process(&cr, crp->data);
+}
+
+static int __thread_stack__flush(struct thread *thread, struct thread_stack *ts)
+{
+ struct call_return_processor *crp = ts->crp;
+ int err;
+
+ if (!crp) {
+ ts->cnt = 0;
+ return 0;
+ }
+
+ while (ts->cnt) {
+ err = thread_stack__call_return(thread, ts, --ts->cnt,
+ ts->last_time, 0, true);
+ if (err) {
+ pr_err("Error flushing thread stack!\n");
+ ts->cnt = 0;
+ return err;
+ }
+ }
+
+ return 0;
+}
+
+int thread_stack__flush(struct thread *thread)
+{
+ if (thread->ts)
+ return __thread_stack__flush(thread, thread->ts);
+
+ return 0;
+}
+
+int thread_stack__event(struct thread *thread, u32 flags, u64 from_ip,
+ u64 to_ip, u16 insn_len, u64 trace_nr)
+{
+ if (!thread)
+ return -EINVAL;
+
+ if (!thread->ts) {
+ thread->ts = thread_stack__new(thread, NULL);
+ if (!thread->ts) {
+ pr_warning("Out of memory: no thread stack\n");
+ return -ENOMEM;
+ }
+ thread->ts->trace_nr = trace_nr;
+ }
+
+ /*
+ * When the trace is discontinuous, the trace_nr changes. In that case
+ * the stack might be completely invalid. Better to report nothing than
+ * to report something misleading, so flush the stack.
+ */
+ if (trace_nr != thread->ts->trace_nr) {
+ if (thread->ts->trace_nr)
+ __thread_stack__flush(thread, thread->ts);
+ thread->ts->trace_nr = trace_nr;
+ }
+
+ /* Stop here if thread_stack__process() is in use */
+ if (thread->ts->crp)
+ return 0;
+
+ if (flags & PERF_IP_FLAG_CALL) {
+ u64 ret_addr;
+
+ if (!to_ip)
+ return 0;
+ ret_addr = from_ip + insn_len;
+ if (ret_addr == to_ip)
+ return 0; /* Zero-length calls are excluded */
+ return thread_stack__push(thread->ts, ret_addr);
+ } else if (flags & PERF_IP_FLAG_RETURN) {
+ if (!from_ip)
+ return 0;
+ thread_stack__pop(thread->ts, to_ip);
+ }
+
+ return 0;
+}
+
+void thread_stack__set_trace_nr(struct thread *thread, u64 trace_nr)
+{
+ if (!thread || !thread->ts)
+ return;
+
+ if (trace_nr != thread->ts->trace_nr) {
+ if (thread->ts->trace_nr)
+ __thread_stack__flush(thread, thread->ts);
+ thread->ts->trace_nr = trace_nr;
+ }
+}
+
+void thread_stack__free(struct thread *thread)
+{
+ if (thread->ts) {
+ __thread_stack__flush(thread, thread->ts);
+ zfree(&thread->ts->stack);
+ zfree(&thread->ts);
+ }
+}
+
+static inline u64 callchain_context(u64 ip, u64 kernel_start)
+{
+ return ip < kernel_start ? PERF_CONTEXT_USER : PERF_CONTEXT_KERNEL;
+}
+
+void thread_stack__sample(struct thread *thread, struct ip_callchain *chain,
+ size_t sz, u64 ip, u64 kernel_start)
+{
+ u64 context = callchain_context(ip, kernel_start);
+ u64 last_context;
+ size_t i, j;
+
+ if (sz < 2) {
+ chain->nr = 0;
+ return;
+ }
+
+ chain->ips[0] = context;
+ chain->ips[1] = ip;
+
+ if (!thread || !thread->ts) {
+ chain->nr = 2;
+ return;
+ }
+
+ last_context = context;
+
+ for (i = 2, j = 1; i < sz && j <= thread->ts->cnt; i++, j++) {
+ ip = thread->ts->stack[thread->ts->cnt - j].ret_addr;
+ context = callchain_context(ip, kernel_start);
+ if (context != last_context) {
+ if (i >= sz - 1)
+ break;
+ chain->ips[i++] = context;
+ last_context = context;
+ }
+ chain->ips[i] = ip;
+ }
+
+ chain->nr = i;
+}
+
+struct call_return_processor *
+call_return_processor__new(int (*process)(struct call_return *cr, void *data),
+ void *data)
+{
+ struct call_return_processor *crp;
+
+ crp = zalloc(sizeof(struct call_return_processor));
+ if (!crp)
+ return NULL;
+ crp->cpr = call_path_root__new();
+ if (!crp->cpr)
+ goto out_free;
+ crp->process = process;
+ crp->data = data;
+ return crp;
+
+out_free:
+ free(crp);
+ return NULL;
+}
+
+void call_return_processor__free(struct call_return_processor *crp)
+{
+ if (crp) {
+ call_path_root__free(crp->cpr);
+ free(crp);
+ }
+}
+
+static int thread_stack__push_cp(struct thread_stack *ts, u64 ret_addr,
+ u64 timestamp, u64 ref, struct call_path *cp,
+ bool no_call)
+{
+ struct thread_stack_entry *tse;
+ int err;
+
+ if (ts->cnt == ts->sz) {
+ err = thread_stack__grow(ts);
+ if (err)
+ return err;
+ }
+
+ tse = &ts->stack[ts->cnt++];
+ tse->ret_addr = ret_addr;
+ tse->timestamp = timestamp;
+ tse->ref = ref;
+ tse->branch_count = ts->branch_count;
+ tse->cp = cp;
+ tse->no_call = no_call;
+
+ return 0;
+}
+
+static int thread_stack__pop_cp(struct thread *thread, struct thread_stack *ts,
+ u64 ret_addr, u64 timestamp, u64 ref,
+ struct symbol *sym)
+{
+ int err;
+
+ if (!ts->cnt)
+ return 1;
+
+ if (ts->cnt == 1) {
+ struct thread_stack_entry *tse = &ts->stack[0];
+
+ if (tse->cp->sym == sym)
+ return thread_stack__call_return(thread, ts, --ts->cnt,
+ timestamp, ref, false);
+ }
+
+ if (ts->stack[ts->cnt - 1].ret_addr == ret_addr) {
+ 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)
+ continue;
+ i += 1;
+ while (ts->cnt > i) {
+ err = thread_stack__call_return(thread, ts,
+ --ts->cnt,
+ timestamp, ref,
+ true);
+ if (err)
+ return err;
+ }
+ return thread_stack__call_return(thread, ts, --ts->cnt,
+ timestamp, ref, false);
+ }
+ }
+
+ return 1;
+}
+
+static int thread_stack__bottom(struct thread *thread, struct thread_stack *ts,
+ struct perf_sample *sample,
+ struct addr_location *from_al,
+ struct addr_location *to_al, u64 ref)
+{
+ struct call_path_root *cpr = ts->crp->cpr;
+ struct call_path *cp;
+ struct symbol *sym;
+ u64 ip;
+
+ if (sample->ip) {
+ ip = sample->ip;
+ sym = from_al->sym;
+ } else if (sample->addr) {
+ ip = sample->addr;
+ sym = to_al->sym;
+ } else {
+ return 0;
+ }
+
+ cp = call_path__findnew(cpr, &cpr->call_path, sym, ip,
+ ts->kernel_start);
+ if (!cp)
+ return -ENOMEM;
+
+ return thread_stack__push_cp(thread->ts, ip, sample->time, ref, cp,
+ true);
+}
+
+static int thread_stack__no_call_return(struct thread *thread,
+ struct thread_stack *ts,
+ struct perf_sample *sample,
+ struct addr_location *from_al,
+ struct addr_location *to_al, u64 ref)
+{
+ struct call_path_root *cpr = ts->crp->cpr;
+ struct call_path *cp, *parent;
+ u64 ks = ts->kernel_start;
+ int err;
+
+ if (sample->ip >= ks && sample->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;
+ }
+
+ /* 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);
+ }
+ } else if (thread_stack__in_kernel(ts) && sample->ip < 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;
+ }
+ }
+
+ if (ts->cnt)
+ parent = ts->stack[ts->cnt - 1].cp;
+ else
+ parent = &cpr->call_path;
+
+ /* 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;
+
+ err = thread_stack__push_cp(ts, sample->addr, sample->time, ref, cp,
+ true);
+ if (err)
+ return err;
+
+ return thread_stack__pop_cp(thread, ts, sample->addr, sample->time, ref,
+ to_al->sym);
+}
+
+static int thread_stack__trace_begin(struct thread *thread,
+ struct thread_stack *ts, u64 timestamp,
+ u64 ref)
+{
+ struct thread_stack_entry *tse;
+ int err;
+
+ if (!ts->cnt)
+ return 0;
+
+ /* Pop trace end */
+ tse = &ts->stack[ts->cnt - 1];
+ if (tse->cp->sym == NULL && tse->cp->ip == 0) {
+ err = thread_stack__call_return(thread, ts, --ts->cnt,
+ timestamp, ref, false);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+static int thread_stack__trace_end(struct thread_stack *ts,
+ struct perf_sample *sample, u64 ref)
+{
+ struct call_path_root *cpr = ts->crp->cpr;
+ struct call_path *cp;
+ u64 ret_addr;
+
+ /* No point having 'trace end' on the bottom of the stack */
+ if (!ts->cnt || (ts->cnt == 1 && ts->stack[0].ref == ref))
+ return 0;
+
+ 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;
+
+ return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp,
+ false);
+}
+
+int thread_stack__process(struct thread *thread, struct comm *comm,
+ struct perf_sample *sample,
+ struct addr_location *from_al,
+ struct addr_location *to_al, u64 ref,
+ struct call_return_processor *crp)
+{
+ struct thread_stack *ts = thread->ts;
+ int err = 0;
+
+ if (ts) {
+ if (!ts->crp) {
+ /* Supersede thread_stack__event() */
+ thread_stack__free(thread);
+ thread->ts = thread_stack__new(thread, crp);
+ if (!thread->ts)
+ return -ENOMEM;
+ ts = thread->ts;
+ ts->comm = comm;
+ }
+ } else {
+ thread->ts = thread_stack__new(thread, crp);
+ if (!thread->ts)
+ return -ENOMEM;
+ ts = thread->ts;
+ ts->comm = comm;
+ }
+
+ /* Flush stack on exec */
+ if (ts->comm != comm && thread->pid_ == thread->tid) {
+ err = __thread_stack__flush(thread, ts);
+ if (err)
+ return err;
+ ts->comm = comm;
+ }
+
+ /* If the stack is empty, put the current symbol on the stack */
+ if (!ts->cnt) {
+ err = thread_stack__bottom(thread, ts, sample, from_al, to_al,
+ ref);
+ if (err)
+ return err;
+ }
+
+ ts->branch_count += 1;
+ ts->last_time = sample->time;
+
+ if (sample->flags & PERF_IP_FLAG_CALL) {
+ struct call_path_root *cpr = ts->crp->cpr;
+ struct call_path *cp;
+ u64 ret_addr;
+
+ if (!sample->ip || !sample->addr)
+ return 0;
+
+ ret_addr = sample->ip + sample->insn_len;
+ if (ret_addr == sample->addr)
+ return 0; /* Zero-length calls are excluded */
+
+ 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);
+ } else if (sample->flags & PERF_IP_FLAG_RETURN) {
+ if (!sample->ip || !sample->addr)
+ return 0;
+
+ err = thread_stack__pop_cp(thread, ts, sample->addr,
+ sample->time, ref, from_al->sym);
+ if (err) {
+ if (err < 0)
+ return err;
+ err = thread_stack__no_call_return(thread, ts, sample,
+ from_al, to_al, ref);
+ }
+ } else if (sample->flags & PERF_IP_FLAG_TRACE_BEGIN) {
+ 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);
+ }
+
+ return err;
+}
+
+size_t thread_stack__depth(struct thread *thread)
+{
+ if (!thread->ts)
+ return 0;
+ return thread->ts->cnt;
+}