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kernel/linux-imx6_3.14.28/tools/perf/util/data.c 2.31 KB
6b13f685e   김민수   BSP 최초 추가
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  #include <linux/compiler.h>
  #include <linux/kernel.h>
  #include <sys/types.h>
  #include <sys/stat.h>
  #include <unistd.h>
  #include <string.h>
  
  #include "data.h"
  #include "util.h"
  
  static bool check_pipe(struct perf_data_file *file)
  {
  	struct stat st;
  	bool is_pipe = false;
  	int fd = perf_data_file__is_read(file) ?
  		 STDIN_FILENO : STDOUT_FILENO;
  
  	if (!file->path) {
  		if (!fstat(fd, &st) && S_ISFIFO(st.st_mode))
  			is_pipe = true;
  	} else {
  		if (!strcmp(file->path, "-"))
  			is_pipe = true;
  	}
  
  	if (is_pipe)
  		file->fd = fd;
  
  	return file->is_pipe = is_pipe;
  }
  
  static int check_backup(struct perf_data_file *file)
  {
  	struct stat st;
  
  	if (!stat(file->path, &st) && st.st_size) {
  		/* TODO check errors properly */
  		char oldname[PATH_MAX];
  		snprintf(oldname, sizeof(oldname), "%s.old",
  			 file->path);
  		unlink(oldname);
  		rename(file->path, oldname);
  	}
  
  	return 0;
  }
  
  static int open_file_read(struct perf_data_file *file)
  {
  	struct stat st;
  	int fd;
  
  	fd = open(file->path, O_RDONLY);
  	if (fd < 0) {
  		int err = errno;
  
  		pr_err("failed to open %s: %s", file->path, strerror(err));
  		if (err == ENOENT && !strcmp(file->path, "perf.data"))
  			pr_err("  (try 'perf record' first)");
  		pr_err("
  ");
  		return -err;
  	}
  
  	if (fstat(fd, &st) < 0)
  		goto out_close;
  
  	if (!file->force && st.st_uid && (st.st_uid != geteuid())) {
  		pr_err("file %s not owned by current user or root
  ",
  		       file->path);
  		goto out_close;
  	}
  
  	if (!st.st_size) {
  		pr_info("zero-sized file (%s), nothing to do!
  ",
  			file->path);
  		goto out_close;
  	}
  
  	file->size = st.st_size;
  	return fd;
  
   out_close:
  	close(fd);
  	return -1;
  }
  
  static int open_file_write(struct perf_data_file *file)
  {
  	if (check_backup(file))
  		return -1;
  
  	return open(file->path, O_CREAT|O_RDWR|O_TRUNC, S_IRUSR|S_IWUSR);
  }
  
  static int open_file(struct perf_data_file *file)
  {
  	int fd;
  
  	fd = perf_data_file__is_read(file) ?
  	     open_file_read(file) : open_file_write(file);
  
  	file->fd = fd;
  	return fd < 0 ? -1 : 0;
  }
  
  int perf_data_file__open(struct perf_data_file *file)
  {
  	if (check_pipe(file))
  		return 0;
  
  	if (!file->path)
  		file->path = "perf.data";
  
  	return open_file(file);
  }
  
  void perf_data_file__close(struct perf_data_file *file)
  {
  	close(file->fd);
  }
  
  ssize_t perf_data_file__write(struct perf_data_file *file,
  			      void *buf, size_t size)
  {
  	return writen(file->fd, buf, size);
  }