// SPDX-License-Identifier: GPL-2.0
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#include <linux/compiler.h>
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#include <linux/types.h>
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#include <inttypes.h>
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#include <unistd.h>
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#include "tests.h"
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#include "debug.h"
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#include "machine.h"
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#include "event.h"
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#include "../util/unwind.h"
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#include "perf_regs.h"
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#include "map.h"
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#include "thread.h"
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#include "callchain.h"
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#if defined (__x86_64__) || defined (__i386__) || defined (__powerpc__)
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#include "arch-tests.h"
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#endif
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/* For bsearch. We try to unwind functions in shared object. */
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#include <stdlib.h>
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static int mmap_handler(struct perf_tool *tool __maybe_unused,
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union perf_event *event,
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struct perf_sample *sample,
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struct machine *machine)
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{
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return machine__process_mmap2_event(machine, event, sample);
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}
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static int init_live_machine(struct machine *machine)
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{
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union perf_event event;
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pid_t pid = getpid();
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return perf_event__synthesize_mmap_events(NULL, &event, pid, pid,
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mmap_handler, machine, true, 500);
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}
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/*
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* We need to keep these functions global, despite the
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* fact that they are used only locally in this object,
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* in order to keep them around even if the binary is
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* stripped. If they are gone, the unwind check for
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* symbol fails.
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*/
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int test_dwarf_unwind__thread(struct thread *thread);
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int test_dwarf_unwind__compare(void *p1, void *p2);
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int test_dwarf_unwind__krava_3(struct thread *thread);
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int test_dwarf_unwind__krava_2(struct thread *thread);
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int test_dwarf_unwind__krava_1(struct thread *thread);
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#define MAX_STACK 8
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static int unwind_entry(struct unwind_entry *entry, void *arg)
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{
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unsigned long *cnt = (unsigned long *) arg;
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char *symbol = entry->sym ? entry->sym->name : NULL;
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static const char *funcs[MAX_STACK] = {
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"test__arch_unwind_sample",
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"test_dwarf_unwind__thread",
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"test_dwarf_unwind__compare",
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"bsearch",
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"test_dwarf_unwind__krava_3",
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"test_dwarf_unwind__krava_2",
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"test_dwarf_unwind__krava_1",
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"test__dwarf_unwind"
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};
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/*
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* The funcs[MAX_STACK] array index, based on the
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* callchain order setup.
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*/
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int idx = callchain_param.order == ORDER_CALLER ?
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MAX_STACK - *cnt - 1 : *cnt;
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if (*cnt >= MAX_STACK) {
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pr_debug("failed: crossed the max stack value %d\n", MAX_STACK);
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return -1;
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}
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if (!symbol) {
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pr_debug("failed: got unresolved address 0x%" PRIx64 "\n",
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entry->ip);
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return -1;
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}
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(*cnt)++;
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pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n",
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symbol, entry->ip, funcs[idx]);
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return strcmp((const char *) symbol, funcs[idx]);
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}
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noinline int test_dwarf_unwind__thread(struct thread *thread)
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{
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struct perf_sample sample;
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unsigned long cnt = 0;
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int err = -1;
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memset(&sample, 0, sizeof(sample));
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if (test__arch_unwind_sample(&sample, thread)) {
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pr_debug("failed to get unwind sample\n");
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goto out;
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}
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err = unwind__get_entries(unwind_entry, &cnt, thread,
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&sample, MAX_STACK);
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if (err)
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pr_debug("unwind failed\n");
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else if (cnt != MAX_STACK) {
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pr_debug("got wrong number of stack entries %lu != %d\n",
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cnt, MAX_STACK);
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err = -1;
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}
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out:
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free(sample.user_stack.data);
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free(sample.user_regs.regs);
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return err;
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}
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static int global_unwind_retval = -INT_MAX;
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noinline int test_dwarf_unwind__compare(void *p1, void *p2)
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{
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/* Any possible value should be 'thread' */
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struct thread *thread = *(struct thread **)p1;
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if (global_unwind_retval == -INT_MAX) {
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/* Call unwinder twice for both callchain orders. */
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callchain_param.order = ORDER_CALLER;
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global_unwind_retval = test_dwarf_unwind__thread(thread);
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if (!global_unwind_retval) {
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callchain_param.order = ORDER_CALLEE;
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global_unwind_retval = test_dwarf_unwind__thread(thread);
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}
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}
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return p1 - p2;
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}
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noinline int test_dwarf_unwind__krava_3(struct thread *thread)
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{
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struct thread *array[2] = {thread, thread};
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void *fp = &bsearch;
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/*
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* make _bsearch a volatile function pointer to
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* prevent potential optimization, which may expand
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* bsearch and call compare directly from this function,
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* instead of libc shared object.
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*/
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void *(*volatile _bsearch)(void *, void *, size_t,
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size_t, int (*)(void *, void *));
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_bsearch = fp;
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_bsearch(array, &thread, 2, sizeof(struct thread **),
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test_dwarf_unwind__compare);
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return global_unwind_retval;
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}
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noinline int test_dwarf_unwind__krava_2(struct thread *thread)
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{
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return test_dwarf_unwind__krava_3(thread);
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}
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noinline int test_dwarf_unwind__krava_1(struct thread *thread)
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{
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return test_dwarf_unwind__krava_2(thread);
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}
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int test__dwarf_unwind(struct test *test __maybe_unused, int subtest __maybe_unused)
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{
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struct machine *machine;
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struct thread *thread;
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int err = -1;
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machine = machine__new_host();
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if (!machine) {
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pr_err("Could not get machine\n");
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return -1;
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}
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if (machine__create_kernel_maps(machine)) {
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pr_err("Failed to create kernel maps\n");
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return -1;
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}
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callchain_param.record_mode = CALLCHAIN_DWARF;
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dwarf_callchain_users = true;
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if (init_live_machine(machine)) {
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pr_err("Could not init machine\n");
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goto out;
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}
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if (verbose > 1)
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machine__fprintf(machine, stderr);
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thread = machine__find_thread(machine, getpid(), getpid());
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if (!thread) {
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pr_err("Could not get thread\n");
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goto out;
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}
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err = test_dwarf_unwind__krava_1(thread);
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thread__put(thread);
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out:
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machine__delete_threads(machine);
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machine__delete(machine);
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return err;
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}
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