ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/tools/perf/util/thread-stack.c b/marvell/linux/tools/perf/util/thread-stack.c
new file mode 100644
index 0000000..cd8a948
--- /dev/null
+++ b/marvell/linux/tools/perf/util/thread-stack.c
@@ -0,0 +1,988 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * thread-stack.c: Synthesize a thread's stack using call / return events
+ * Copyright (c) 2014, Intel Corporation.
+ */
+
+#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 "env.h"
+#include "debug.h"
+#include "symbol.h"
+#include "comm.h"
+#include "call-path.h"
+#include "thread-stack.h"
+
+#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;
+};
+
+/**
+ * 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
+ * @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
+ */
+struct thread_stack {
+ struct thread_stack_entry *stack;
+ size_t cnt;
+ 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;
+};
+
+/*
+ * Assume pid == tid == 0 identifies the idle task as defined by
+ * perf_session__register_idle_thread(). The idle task is really 1 task per cpu,
+ * and therefore requires a stack for each cpu.
+ */
+static inline bool thread_stack__per_cpu(struct thread *thread)
+{
+ return !(thread->tid || thread->pid_);
+}
+
+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 int thread_stack__init(struct thread_stack *ts, struct thread *thread,
+ struct call_return_processor *crp)
+{
+ int err;
+
+ err = thread_stack__grow(ts);
+ if (err)
+ return err;
+
+ if (thread->mg && thread->mg->machine) {
+ struct machine *machine = thread->mg->machine;
+ 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 thread_stack *ts = thread->ts, *new_ts;
+ unsigned int old_sz = ts ? ts->arr_sz : 0;
+ unsigned int new_sz = 1;
+
+ if (thread_stack__per_cpu(thread) && cpu > 0)
+ new_sz = roundup_pow_of_two(cpu + 1);
+
+ if (!ts || new_sz > old_sz) {
+ new_ts = calloc(new_sz, sizeof(*ts));
+ if (!new_ts)
+ return NULL;
+ if (ts)
+ memcpy(new_ts, ts, old_sz * sizeof(*ts));
+ new_ts->arr_sz = new_sz;
+ zfree(&thread->ts);
+ thread->ts = new_ts;
+ ts = new_ts;
+ }
+
+ if (thread_stack__per_cpu(thread) && cpu > 0 &&
+ (unsigned int)cpu < ts->arr_sz)
+ ts += cpu;
+
+ if (!ts->stack &&
+ thread_stack__init(ts, thread, crp))
+ return NULL;
+
+ return ts;
+}
+
+static struct thread_stack *thread__cpu_stack(struct thread *thread, int cpu)
+{
+ struct thread_stack *ts = thread->ts;
+
+ if (cpu < 0)
+ cpu = 0;
+
+ if (!ts || (unsigned int)cpu >= ts->arr_sz)
+ return NULL;
+
+ ts += cpu;
+
+ if (!ts->stack)
+ return NULL;
+
+ return ts;
+}
+
+static inline struct thread_stack *thread__stack(struct thread *thread,
+ int cpu)
+{
+ if (!thread)
+ return NULL;
+
+ if (thread_stack__per_cpu(thread))
+ return thread__cpu_stack(thread, cpu);
+
+ return thread->ts;
+}
+
+static int thread_stack__push(struct thread_stack *ts, u64 ret_addr,
+ bool trace_end)
+{
+ 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].trace_end = trace_end;
+ 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 void thread_stack__pop_trace_end(struct thread_stack *ts)
+{
+ size_t i;
+
+ for (i = ts->cnt; i; ) {
+ if (ts->stack[--i].trace_end)
+ ts->cnt = i;
+ else
+ 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,
+ };
+ 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;
+
+ /*
+ * 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)
+{
+ 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)
+{
+ struct thread_stack *ts = thread->ts;
+ unsigned int pos;
+ int err = 0;
+
+ if (ts) {
+ for (pos = 0; pos < ts->arr_sz; pos++) {
+ int ret = __thread_stack__flush(thread, ts + pos);
+
+ if (ret)
+ err = ret;
+ }
+ }
+
+ return err;
+}
+
+int thread_stack__event(struct thread *thread, int cpu, u32 flags, u64 from_ip,
+ u64 to_ip, u16 insn_len, u64 trace_nr)
+{
+ struct thread_stack *ts = thread__stack(thread, cpu);
+
+ if (!thread)
+ return -EINVAL;
+
+ if (!ts) {
+ ts = thread_stack__new(thread, cpu, NULL);
+ if (!ts) {
+ pr_warning("Out of memory: no thread stack\n");
+ return -ENOMEM;
+ }
+ 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 != ts->trace_nr) {
+ if (ts->trace_nr)
+ __thread_stack__flush(thread, ts);
+ ts->trace_nr = trace_nr;
+ }
+
+ /* Stop here if thread_stack__process() is in use */
+ if (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(ts, ret_addr,
+ flags & PERF_IP_FLAG_TRACE_END);
+ } else if (flags & PERF_IP_FLAG_TRACE_BEGIN) {
+ /*
+ * If the caller did not change the trace number (which would
+ * have flushed the stack) then try to make sense of the stack.
+ * Possibly, tracing began after returning to the current
+ * address, so try to pop that. Also, do not expect a call made
+ * when the trace ended, to return, so pop that.
+ */
+ thread_stack__pop(ts, to_ip);
+ thread_stack__pop_trace_end(ts);
+ } else if ((flags & PERF_IP_FLAG_RETURN) && from_ip) {
+ thread_stack__pop(ts, to_ip);
+ }
+
+ return 0;
+}
+
+void thread_stack__set_trace_nr(struct thread *thread, int cpu, u64 trace_nr)
+{
+ struct thread_stack *ts = thread__stack(thread, cpu);
+
+ if (!ts)
+ return;
+
+ if (trace_nr != ts->trace_nr) {
+ if (ts->trace_nr)
+ __thread_stack__flush(thread, ts);
+ ts->trace_nr = trace_nr;
+ }
+}
+
+static void __thread_stack__free(struct thread *thread, struct thread_stack *ts)
+{
+ __thread_stack__flush(thread, ts);
+ zfree(&ts->stack);
+}
+
+static void thread_stack__reset(struct thread *thread, struct thread_stack *ts)
+{
+ unsigned int arr_sz = ts->arr_sz;
+
+ __thread_stack__free(thread, ts);
+ memset(ts, 0, sizeof(*ts));
+ ts->arr_sz = arr_sz;
+}
+
+void thread_stack__free(struct thread *thread)
+{
+ struct thread_stack *ts = thread->ts;
+ unsigned int pos;
+
+ if (ts) {
+ for (pos = 0; pos < ts->arr_sz; pos++)
+ __thread_stack__free(thread, ts + pos);
+ 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, int cpu,
+ struct ip_callchain *chain,
+ size_t sz, u64 ip, u64 kernel_start)
+{
+ struct thread_stack *ts = thread__stack(thread, cpu);
+ 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 (!ts) {
+ chain->nr = 2;
+ return;
+ }
+
+ last_context = context;
+
+ for (i = 2, j = 1; i < sz && j <= ts->cnt; i++, j++) {
+ ip = ts->stack[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, u64 *parent_db_id, 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, bool trace_end)
+{
+ struct thread_stack_entry *tse;
+ int err;
+
+ if (!cp)
+ return -ENOMEM;
+
+ 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->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;
+}
+
+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 &&
+ !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 ||
+ ts->stack[i].non_call)
+ 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_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);
+
+ 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,
+ struct addr_location *from_al,
+ 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 (ip >= ks && addr < ks) {
+ /* Return to userspace, so pop all kernel addresses */
+ 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, root, tsym, addr, ks);
+ return thread_stack__push_cp(ts, 0, tm, ref, cp, true,
+ false);
+ }
+ } else if (thread_stack__in_kernel(ts) && ip < ks) {
+ /* Return to userspace, so pop all kernel addresses */
+ 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,
+ 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;
+ }
+
+ /*
+ * Assume 'parent' has not yet returned, so push 'to', and then push and
+ * pop 'from'.
+ */
+
+ 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, ip, tm, ref, cp, true, false);
+ if (err)
+ return err;
+
+ return thread_stack__call_return(thread, ts, --ts->cnt, tm, ref, false);
+}
+
+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->trace_end) {
+ 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);
+
+ ret_addr = sample->ip + sample->insn_len;
+
+ return thread_stack__push_cp(ts, ret_addr, sample->time, ref, cp,
+ false, true);
+}
+
+static bool is_x86_retpoline(const char *name)
+{
+ const char *p = strstr(name, "__x86_indirect_thunk_");
+
+ return p == name || !strcmp(name, "__indirect_thunk_start");
+}
+
+/*
+ * 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,
+ struct addr_location *to_al, u64 ref,
+ 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) {
+ /* Supersede thread_stack__event() */
+ thread_stack__reset(thread, ts);
+ ts = NULL;
+ }
+
+ if (!ts) {
+ ts = thread_stack__new(thread, sample->cpu, crp);
+ 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) {
+ 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(ts, sample, from_al, to_al, ref);
+ if (err)
+ return err;
+ }
+
+ 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) {
+ bool trace_end = sample->flags & PERF_IP_FLAG_TRACE_END;
+ 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);
+ 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->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) {
+ 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);
+ } 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;
+}
+
+size_t thread_stack__depth(struct thread *thread, int cpu)
+{
+ struct thread_stack *ts = thread__stack(thread, cpu);
+
+ if (!ts)
+ return 0;
+ return ts->cnt;
+}