From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sun, 7 Apr 2024 20:49:45 +0200 Subject: Adding upstream version 6.1.76. Signed-off-by: Daniel Baumann --- tools/perf/tests/dwarf-unwind.c | 242 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 242 insertions(+) create mode 100644 tools/perf/tests/dwarf-unwind.c (limited to 'tools/perf/tests/dwarf-unwind.c') diff --git a/tools/perf/tests/dwarf-unwind.c b/tools/perf/tests/dwarf-unwind.c new file mode 100644 index 000000000..afdca7f29 --- /dev/null +++ b/tools/perf/tests/dwarf-unwind.c @@ -0,0 +1,242 @@ +// SPDX-License-Identifier: GPL-2.0 +#include +#include +#include +#include +#include +#include +#include "tests.h" +#include "debug.h" +#include "machine.h" +#include "event.h" +#include "../util/unwind.h" +#include "perf_regs.h" +#include "map.h" +#include "symbol.h" +#include "thread.h" +#include "callchain.h" +#include "util/synthetic-events.h" + +/* For bsearch. We try to unwind functions in shared object. */ +#include + +/* + * The test will assert frames are on the stack but tail call optimizations lose + * the frame of the caller. Clang can disable this optimization on a called + * function but GCC currently (11/2020) lacks this attribute. The barrier is + * used to inhibit tail calls in these cases. + */ +#ifdef __has_attribute +#if __has_attribute(disable_tail_calls) +#define NO_TAIL_CALL_ATTRIBUTE __attribute__((disable_tail_calls)) +#define NO_TAIL_CALL_BARRIER +#endif +#endif +#ifndef NO_TAIL_CALL_ATTRIBUTE +#define NO_TAIL_CALL_ATTRIBUTE +#define NO_TAIL_CALL_BARRIER __asm__ __volatile__("" : : : "memory"); +#endif + +static int mmap_handler(struct perf_tool *tool __maybe_unused, + union perf_event *event, + struct perf_sample *sample, + struct machine *machine) +{ + return machine__process_mmap2_event(machine, event, sample); +} + +static int init_live_machine(struct machine *machine) +{ + union perf_event event; + pid_t pid = getpid(); + + memset(&event, 0, sizeof(event)); + return perf_event__synthesize_mmap_events(NULL, &event, pid, pid, + mmap_handler, machine, true); +} + +/* + * We need to keep these functions global, despite the + * fact that they are used only locally in this object, + * in order to keep them around even if the binary is + * stripped. If they are gone, the unwind check for + * symbol fails. + */ +int test_dwarf_unwind__thread(struct thread *thread); +int test_dwarf_unwind__compare(void *p1, void *p2); +int test_dwarf_unwind__krava_3(struct thread *thread); +int test_dwarf_unwind__krava_2(struct thread *thread); +int test_dwarf_unwind__krava_1(struct thread *thread); + +#define MAX_STACK 8 + +static int unwind_entry(struct unwind_entry *entry, void *arg) +{ + unsigned long *cnt = (unsigned long *) arg; + char *symbol = entry->ms.sym ? entry->ms.sym->name : NULL; + static const char *funcs[MAX_STACK] = { + "test__arch_unwind_sample", + "test_dwarf_unwind__thread", + "test_dwarf_unwind__compare", + "bsearch", + "test_dwarf_unwind__krava_3", + "test_dwarf_unwind__krava_2", + "test_dwarf_unwind__krava_1", + "test__dwarf_unwind" + }; + /* + * The funcs[MAX_STACK] array index, based on the + * callchain order setup. + */ + int idx = callchain_param.order == ORDER_CALLER ? + MAX_STACK - *cnt - 1 : *cnt; + + if (*cnt >= MAX_STACK) { + pr_debug("failed: crossed the max stack value %d\n", MAX_STACK); + return -1; + } + + if (!symbol) { + pr_debug("failed: got unresolved address 0x%" PRIx64 "\n", + entry->ip); + return -1; + } + + (*cnt)++; + pr_debug("got: %s 0x%" PRIx64 ", expecting %s\n", + symbol, entry->ip, funcs[idx]); + return strcmp((const char *) symbol, funcs[idx]); +} + +NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__thread(struct thread *thread) +{ + struct perf_sample sample; + unsigned long cnt = 0; + int err = -1; + + memset(&sample, 0, sizeof(sample)); + + if (test__arch_unwind_sample(&sample, thread)) { + pr_debug("failed to get unwind sample\n"); + goto out; + } + + err = unwind__get_entries(unwind_entry, &cnt, thread, + &sample, MAX_STACK, false); + if (err) + pr_debug("unwind failed\n"); + else if (cnt != MAX_STACK) { + pr_debug("got wrong number of stack entries %lu != %d\n", + cnt, MAX_STACK); + err = -1; + } + + out: + zfree(&sample.user_stack.data); + zfree(&sample.user_regs.regs); + return err; +} + +static int global_unwind_retval = -INT_MAX; + +NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__compare(void *p1, void *p2) +{ + /* Any possible value should be 'thread' */ + struct thread *thread = *(struct thread **)p1; + + if (global_unwind_retval == -INT_MAX) { + /* Call unwinder twice for both callchain orders. */ + callchain_param.order = ORDER_CALLER; + + global_unwind_retval = test_dwarf_unwind__thread(thread); + if (!global_unwind_retval) { + callchain_param.order = ORDER_CALLEE; + global_unwind_retval = test_dwarf_unwind__thread(thread); + } + } + + return p1 - p2; +} + +NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_3(struct thread *thread) +{ + struct thread *array[2] = {thread, thread}; + void *fp = &bsearch; + /* + * make _bsearch a volatile function pointer to + * prevent potential optimization, which may expand + * bsearch and call compare directly from this function, + * instead of libc shared object. + */ + void *(*volatile _bsearch)(void *, void *, size_t, + size_t, int (*)(void *, void *)); + + _bsearch = fp; + _bsearch(array, &thread, 2, sizeof(struct thread **), + test_dwarf_unwind__compare); + return global_unwind_retval; +} + +NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_2(struct thread *thread) +{ + int ret; + + ret = test_dwarf_unwind__krava_3(thread); + NO_TAIL_CALL_BARRIER; + return ret; +} + +NO_TAIL_CALL_ATTRIBUTE noinline int test_dwarf_unwind__krava_1(struct thread *thread) +{ + int ret; + + ret = test_dwarf_unwind__krava_2(thread); + NO_TAIL_CALL_BARRIER; + return ret; +} + +static int test__dwarf_unwind(struct test_suite *test __maybe_unused, + int subtest __maybe_unused) +{ + struct machine *machine; + struct thread *thread; + int err = -1; + + machine = machine__new_host(); + if (!machine) { + pr_err("Could not get machine\n"); + return -1; + } + + if (machine__create_kernel_maps(machine)) { + pr_err("Failed to create kernel maps\n"); + return -1; + } + + callchain_param.record_mode = CALLCHAIN_DWARF; + dwarf_callchain_users = true; + + if (init_live_machine(machine)) { + pr_err("Could not init machine\n"); + goto out; + } + + if (verbose > 1) + machine__fprintf(machine, stderr); + + thread = machine__find_thread(machine, getpid(), getpid()); + if (!thread) { + pr_err("Could not get thread\n"); + goto out; + } + + err = test_dwarf_unwind__krava_1(thread); + thread__put(thread); + + out: + machine__delete_threads(machine); + machine__delete(machine); + return err; +} + +DEFINE_SUITE("Test dwarf unwind", dwarf_unwind); -- cgit v1.2.3