From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/tools/perf/tests/dwarf-unwind.c | 179 +++++++++++++++++++++++++++++++++ 1 file changed, 179 insertions(+) create mode 100644 kernel/tools/perf/tests/dwarf-unwind.c (limited to 'kernel/tools/perf/tests/dwarf-unwind.c') diff --git a/kernel/tools/perf/tests/dwarf-unwind.c b/kernel/tools/perf/tests/dwarf-unwind.c new file mode 100644 index 000000000..0bf06bec6 --- /dev/null +++ b/kernel/tools/perf/tests/dwarf-unwind.c @@ -0,0 +1,179 @@ +#include +#include +#include +#include "tests.h" +#include "debug.h" +#include "machine.h" +#include "event.h" +#include "unwind.h" +#include "perf_regs.h" +#include "map.h" +#include "thread.h" +#include "callchain.h" + +/* For bsearch. We try to unwind functions in shared object. */ +#include + +static int mmap_handler(struct perf_tool *tool __maybe_unused, + union perf_event *event, + struct perf_sample *sample __maybe_unused, + struct machine *machine) +{ + return machine__process_mmap2_event(machine, event, NULL); +} + +static int init_live_machine(struct machine *machine) +{ + union perf_event event; + pid_t pid = getpid(); + + return perf_event__synthesize_mmap_events(NULL, &event, pid, pid, + mmap_handler, machine, true); +} + +#define MAX_STACK 8 + +static int unwind_entry(struct unwind_entry *entry, void *arg) +{ + unsigned long *cnt = (unsigned long *) arg; + char *symbol = entry->sym ? entry->sym->name : NULL; + static const char *funcs[MAX_STACK] = { + "test__arch_unwind_sample", + "unwind_thread", + "compare", + "bsearch", + "krava_3", + "krava_2", + "krava_1", + "test__dwarf_unwind" + }; + + 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; + } + + pr_debug("got: %s 0x%" PRIx64 "\n", symbol, entry->ip); + return strcmp((const char *) symbol, funcs[(*cnt)++]); +} + +__attribute__ ((noinline)) +static int 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); + 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: + free(sample.user_stack.data); + free(sample.user_regs.regs); + return err; +} + +static int global_unwind_retval = -INT_MAX; + +__attribute__ ((noinline)) +static int compare(void *p1, void *p2) +{ + /* Any possible value should be 'thread' */ + struct thread *thread = *(struct thread **)p1; + + if (global_unwind_retval == -INT_MAX) + global_unwind_retval = unwind_thread(thread); + + return p1 - p2; +} + +__attribute__ ((noinline)) +static int 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 **), compare); + return global_unwind_retval; +} + +__attribute__ ((noinline)) +static int krava_2(struct thread *thread) +{ + return krava_3(thread); +} + +__attribute__ ((noinline)) +static int krava_1(struct thread *thread) +{ + return krava_2(thread); +} + +int test__dwarf_unwind(void) +{ + struct machines machines; + struct machine *machine; + struct thread *thread; + int err = -1; + + machines__init(&machines); + + machine = machines__find(&machines, HOST_KERNEL_ID); + if (!machine) { + pr_err("Could not get machine\n"); + return -1; + } + + callchain_param.record_mode = CALLCHAIN_DWARF; + + 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 = krava_1(thread); + + out: + machine__delete_threads(machine); + machine__exit(machine); + machines__exit(&machines); + return err; +} -- cgit 1.2.3-korg