minix/servers/vfs/gcov.c

   1
   2 #include <string.h>
   3
   4 #include "fs.h"
   5 #include "file.h"
   6
   7 /*===========================================================================*
   8  *                              do_gcov_flush                                *
   9  *===========================================================================*/
  10 int do_gcov_flush(void)
  11 {
  12 /* A userland tool has requested the gcov data from another
  13  * process (possibly vfs itself). Grant the target process
  14  * access to the supplied buffer, and perform the call that
  15  * makes the target copy its buffer to the caller (incl vfs
  16  * itself).
  17  */
  18   char label[LABEL_MAX];
  19   vir_bytes labeladdr, buf;
  20   size_t labellen, size;
  21   endpoint_t endpt;
  22   cp_grant_id_t grantid;
  23   int r;
  24   message m;
  25
  26   /*
  27    * Something as sensitive as system service coverage information must be
  28    * call to the target service, and so it is not impossible to deadlock the
  29    * system with this call.
  30    */
  31   if (!super_user) return(EPERM);
  32
  33   labeladdr = job_m_in.m_lc_vfs_gcov.label;
  34   labellen = job_m_in.m_lc_vfs_gcov.labellen;
  35   buf = job_m_in.m_lc_vfs_gcov.buf;
  36   size = job_m_in.m_lc_vfs_gcov.buflen;
  37
  38   /* Retrieve and look up the target label. */
  39   if (labellen >= sizeof(label))
  40         return EINVAL;
  41   if ((r = sys_datacopy_wrapper(who_e, labeladdr, SELF, (vir_bytes)label,
  42     labellen)) != OK)
  43         return r;
  44   label[labellen - 1] = '\0';
  45
  46   if ((r = ds_retrieve_label_endpt(label, &endpt)) != OK)
  47         return r;
  48
  49   /* Hack: init is the only non-system process with a valid label. */
  50   if (endpt == INIT_PROC_NR)
  51         return ENOENT;
  52
  53   /* Grant target process to requestor's buffer. */
  54   if ((grantid = cpf_grant_magic(endpt, who_e, buf, size, CPF_WRITE)) < 0) {
  55         printf("VFS: gcov_flush: grant failed\n");
  56         return(ENOMEM);
  57   }
  58
  59   if (endpt == VFS_PROC_NR) {
  60         /* Request is for VFS itself. */
  61         r = gcov_flush(VFS_PROC_NR, grantid, size);
  62   } else {
  63         /* Perform generic GCOV request. */
  64         memset(&m, 0, sizeof(m));
  65         m.m_vfs_lsys_gcov.grant = grantid;
  66         m.m_vfs_lsys_gcov.size = size;
  67         r = _taskcall(endpt, COMMON_REQ_GCOV_DATA, &m);
  68   }
  69
  70   cpf_revoke(grantid);
  71
  72   return(r);
  73 }