tools/perf/util/unwind-libunwind.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "unwind.h"
   3 #include "map.h"
   4 #include "thread.h"
   5 #include "session.h"
   6 #include "debug.h"
   7 #include "env.h"
   8 #include "callchain.h"
   9
  10 struct unwind_libunwind_ops __weak *local_unwind_libunwind_ops;
  11 struct unwind_libunwind_ops __weak *x86_32_unwind_libunwind_ops;
  12 struct unwind_libunwind_ops __weak *arm64_unwind_libunwind_ops;
  13
  14 static void unwind__register_ops(struct thread *thread,
  15                           struct unwind_libunwind_ops *ops)
  16 {
  17         thread->unwind_libunwind_ops = ops;
  18 }
  19
  20 int unwind__prepare_access(struct thread *thread, struct map *map,
  21                            bool *initialized)
  22 {
  23         const char *arch;
  24         enum dso_type dso_type;
  25         struct unwind_libunwind_ops *ops = local_unwind_libunwind_ops;
  26         int err;
  27
  28         if (!dwarf_callchain_users)
  29                 return 0;
  30
  31         if (thread->addr_space) {
  32                 pr_debug("unwind: thread map already set, dso=%s\n",
  33                          map->dso->name);
  34                 if (initialized)
  35                         *initialized = true;
  36                 return 0;
  37         }
  38
  39         /* env->arch is NULL for live-mode (i.e. perf top) */
  40         if (!thread->mg->machine->env || !thread->mg->machine->env->arch)
  41                 goto out_register;
  42
  43         dso_type = dso__type(map->dso, thread->mg->machine);
  44         if (dso_type == DSO__TYPE_UNKNOWN)
  45                 return 0;
  46
  47         arch = perf_env__arch(thread->mg->machine->env);
  48
  49         if (!strcmp(arch, "x86")) {
  50                 if (dso_type != DSO__TYPE_64BIT)
  51                         ops = x86_32_unwind_libunwind_ops;
  52         } else if (!strcmp(arch, "arm64") || !strcmp(arch, "arm")) {
  53                 if (dso_type == DSO__TYPE_64BIT)
  54                         ops = arm64_unwind_libunwind_ops;
  55         }
  56
  57         if (!ops) {
  58                 pr_err("unwind: target platform=%s is not supported\n", arch);
  59                 return 0;
  60         }
  61 out_register:
  62         unwind__register_ops(thread, ops);
  63
  64         err = thread->unwind_libunwind_ops->prepare_access(thread);
  65         if (initialized)
  66                 *initialized = err ? false : true;
  67         return err;
  68 }
  69
  70 void unwind__flush_access(struct thread *thread)
  71 {
  72         if (!dwarf_callchain_users)
  73                 return;
  74
  75         if (thread->unwind_libunwind_ops)
  76                 thread->unwind_libunwind_ops->flush_access(thread);
  77 }
  78
  79 void unwind__finish_access(struct thread *thread)
  80 {
  81         if (!dwarf_callchain_users)
  82                 return;
  83
  84         if (thread->unwind_libunwind_ops)
  85                 thread->unwind_libunwind_ops->finish_access(thread);
  86 }
  87
  88 int unwind__get_entries(unwind_entry_cb_t cb, void *arg,
  89                          struct thread *thread,
  90                          struct perf_sample *data, int max_stack)
  91 {
  92         if (thread->unwind_libunwind_ops)
  93                 return thread->unwind_libunwind_ops->get_entries(cb, arg, thread, data, max_stack);
  94         return 0;
  95 }