tools/perf/util/session.c

   1 #include <linux/kernel.h>
   2
   3 #include <unistd.h>
   4 #include <sys/types.h>
   5
   6 #include "session.h"
   7 #include "util.h"
   8
   9 static int perf_session__open(struct perf_session *self, bool force)
  10 {
  11         struct stat input_stat;
  12
  13         self->fd = open(self->filename, O_RDONLY);
  14         if (self->fd < 0) {
  15                 pr_err("failed to open file: %s", self->filename);
  16                 if (!strcmp(self->filename, "perf.data"))
  17                         pr_err("  (try 'perf record' first)");
  18                 pr_err("\n");
  19                 return -errno;
  20         }
  21
  22         if (fstat(self->fd, &input_stat) < 0)
  23                 goto out_close;
  24
  25         if (!force && input_stat.st_uid && (input_stat.st_uid != geteuid())) {
  26                 pr_err("file %s not owned by current user or root\n",
  27                        self->filename);
  28                 goto out_close;
  29         }
  30
  31         if (!input_stat.st_size) {
  32                 pr_info("zero-sized file (%s), nothing to do!\n",
  33                         self->filename);
  34                 goto out_close;
  35         }
  36
  37         if (perf_header__read(&self->header, self->fd) < 0) {
  38                 pr_err("incompatible file format");
  39                 goto out_close;
  40         }
  41
  42         self->size = input_stat.st_size;
  43         return 0;
  44
  45 out_close:
  46         close(self->fd);
  47         self->fd = -1;
  48         return -1;
  49 }
  50
  51 struct perf_session *perf_session__new(const char *filename, int mode,
  52                                        bool force)
  53 {
  54         size_t len = strlen(filename) + 1;
  55         struct perf_session *self = zalloc(sizeof(*self) + len);
  56
  57         if (self == NULL)
  58                 goto out;
  59
  60         if (perf_header__init(&self->header) < 0)
  61                 goto out_delete;
  62
  63         memcpy(self->filename, filename, len);
  64
  65         if (mode == O_RDONLY && perf_session__open(self, force) < 0) {
  66                 perf_session__delete(self);
  67                 self = NULL;
  68         }
  69 out:
  70         return self;
  71 out_delete:
  72         free(self);
  73         return NULL;
  74 }
  75
  76 void perf_session__delete(struct perf_session *self)
  77 {
  78         perf_header__exit(&self->header);
  79         close(self->fd);
  80         free(self);
  81 }