source3/profile/profile.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    store smbd profiling information in shared memory
   4    Copyright (C) Andrew Tridgell 1999
   5
   6    This program is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2 of the License, or
   9    (at your option) any later version.
  10
  11    This program is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with this program; if not, write to the Free Software
  18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  19
  20 */
  21
  22 #include "includes.h"
  23
  24 #ifdef WITH_PROFILE
  25 #define IPC_PERMS ((S_IRUSR | S_IWUSR) | S_IRGRP | S_IROTH)
  26 #endif /* WITH_PROFILE */
  27
  28 #ifdef WITH_PROFILE
  29 static int shm_id;
  30 static BOOL read_only;
  31 #if defined(HAVE_CLOCK_GETTIME)
  32 clockid_t __profile_clock;
  33 BOOL have_profiling_clock = False;
  34 #endif
  35 #endif
  36
  37 struct profile_header *profile_h;
  38 struct profile_stats *profile_p;
  39
  40 BOOL do_profile_flag = False;
  41 BOOL do_profile_times = False;
  42
  43 /****************************************************************************
  44 receive a set profile level message
  45 ****************************************************************************/
  46 void profile_message(int msg_type, struct process_id src, void *buf, size_t len)
  47 {
  48         int level;
  49
  50         memcpy(&level, buf, sizeof(int));
  51 #ifdef WITH_PROFILE
  52         switch (level) {
  53         case 0:         /* turn off profiling */
  54                 do_profile_flag = False;
  55                 do_profile_times = False;
  56                 DEBUG(1,("INFO: Profiling turned OFF from pid %d\n",
  57                          (int)procid_to_pid(&src)));
  58                 break;
  59         case 1:         /* turn on counter profiling only */
  60                 do_profile_flag = True;
  61                 do_profile_times = False;
  62                 DEBUG(1,("INFO: Profiling counts turned ON from pid %d\n",
  63                          (int)procid_to_pid(&src)));
  64                 break;
  65         case 2:         /* turn on complete profiling */
  66
  67 #if defined(HAVE_CLOCK_GETTIME)
  68                 if (!have_profiling_clock) {
  69                         do_profile_flag = True;
  70                         do_profile_times = False;
  71                         DEBUG(1,("INFO: Profiling counts turned ON from "
  72                                 "pid %d\n", (int)procid_to_pid(&src)));
  73                         DEBUGADD(1,("INFO: Profiling times disabled "
  74                                 "due to lack of a suitable clock\n"));
  75                         break;
  76                 }
  77 #endif
  78
  79                 do_profile_flag = True;
  80                 do_profile_times = True;
  81                 DEBUG(1,("INFO: Full profiling turned ON from pid %d\n",
  82                          (int)procid_to_pid(&src)));
  83                 break;
  84         case 3:         /* reset profile values */
  85                 memset((char *)profile_p, 0, sizeof(*profile_p));
  86                 DEBUG(1,("INFO: Profiling values cleared from pid %d\n",
  87                          (int)procid_to_pid(&src)));
  88                 break;
  89         }
  90 #else /* WITH_PROFILE */
  91         DEBUG(1,("INFO: Profiling support unavailable in this build.\n"));
  92 #endif /* WITH_PROFILE */
  93 }
  94
  95 /****************************************************************************
  96 receive a request profile level message
  97 ****************************************************************************/
  98 void reqprofile_message(int msg_type, struct process_id src,
  99                         void *buf, size_t len)
 100 {
 101         int level;
 102
 103 #ifdef WITH_PROFILE
 104         level = 1 + (do_profile_flag?2:0) + (do_profile_times?4:0);
 105 #else
 106         level = 0;
 107 #endif
 108         DEBUG(1,("INFO: Received REQ_PROFILELEVEL message from PID %u\n",
 109                  (unsigned int)procid_to_pid(&src)));
 110         message_send_pid(src, MSG_PROFILELEVEL, &level, sizeof(int), True);
 111 }
 112
 113 /*******************************************************************
 114   open the profiling shared memory area
 115   ******************************************************************/
 116 #ifdef WITH_PROFILE
 117
 118 #ifdef HAVE_CLOCK_GETTIME
 119
 120 /* Find a clock. Just because the definition for a particular clock ID is
 121  * present doesn't mean the system actually supports it.
 122  */
 123 static void init_clock_gettime(void)
 124 {
 125         struct timespec ts;
 126
 127         have_profiling_clock = False;
 128
 129 #ifdef HAVE_CLOCK_PROCESS_CPUTIME_ID
 130         /* CLOCK_PROCESS_CPUTIME_ID is sufficiently fast that the
 131          * always profiling times is plausible. Unfortunately on Linux
 132          * it is only accurate if we can guarantee we will not be scheduled
 133          * scheduled onto a different CPU between samples. Until there is
 134          * some way to set processor affinity, we can only use this on
 135          * uniprocessors.
 136          */
 137         if (!this_is_smp()) {
 138             if (clock_gettime(CLOCK_PROCESS_CPUTIME_ID, &ts) == 0) {
 139                     DEBUG(10, ("Using CLOCK_PROCESS_CPUTIME_ID "
 140                                 "for profile_clock\n"));
 141                     __profile_clock = CLOCK_PROCESS_CPUTIME_ID;
 142                     have_profiling_clock = True;
 143             }
 144         }
 145 #endif
 146
 147 #ifdef HAVE_CLOCK_MONOTONIC
 148         if (!have_profiling_clock &&
 149             clock_gettime(CLOCK_MONOTONIC, &ts) == 0) {
 150                 DEBUG(10, ("Using CLOCK_MONOTONIC for profile_clock\n"));
 151                 __profile_clock = CLOCK_MONOTONIC;
 152                 have_profiling_clock = True;
 153         }
 154 #endif
 155
 156 #ifdef HAVE_CLOCK_REALTIME
 157         /* POSIX says that CLOCK_REALTIME should be defined everywhere
 158          * where we have clock_gettime...
 159          */
 160         if (!have_profiling_clock &&
 161             clock_gettime(CLOCK_REALTIME, &ts) == 0) {
 162                 __profile_clock = CLOCK_REALTIME;
 163                 have_profiling_clock = True;
 164
 165                 SMB_WARN(__profile_clock != CLOCK_REALTIME,
 166                         ("forced to use a slow profiling clock"));
 167         }
 168
 169 #endif
 170
 171         SMB_WARN(have_profiling_clock == True,
 172                 ("could not find a working clock for profiling"));
 173         return;
 174 }
 175 #endif
 176
 177 BOOL profile_setup(BOOL rdonly)
 178 {
 179         struct shmid_ds shm_ds;
 180
 181         read_only = rdonly;
 182
 183 #ifdef HAVE_CLOCK_GETTIME
 184         init_clock_gettime();
 185 #endif
 186
 187  again:
 188         /* try to use an existing key */
 189         shm_id = shmget(PROF_SHMEM_KEY, 0, 0);
 190
 191         /* if that failed then create one. There is a race condition here
 192            if we are running from inetd. Bad luck. */
 193         if (shm_id == -1) {
 194                 if (read_only) return False;
 195                 shm_id = shmget(PROF_SHMEM_KEY, sizeof(*profile_h),
 196                                 IPC_CREAT | IPC_EXCL | IPC_PERMS);
 197         }
 198
 199         if (shm_id == -1) {
 200                 DEBUG(0,("Can't create or use IPC area. Error was %s\n",
 201                          strerror(errno)));
 202                 return False;
 203         }
 204
 205
 206         profile_h = (struct profile_header *)shmat(shm_id, 0,
 207                                                    read_only?SHM_RDONLY:0);
 208         if ((long)profile_p == -1) {
 209                 DEBUG(0,("Can't attach to IPC area. Error was %s\n",
 210                          strerror(errno)));
 211                 return False;
 212         }
 213
 214         /* find out who created this memory area */
 215         if (shmctl(shm_id, IPC_STAT, &shm_ds) != 0) {
 216                 DEBUG(0,("ERROR shmctl : can't IPC_STAT. Error was %s\n",
 217                          strerror(errno)));
 218                 return False;
 219         }
 220
 221         if (shm_ds.shm_perm.cuid != sec_initial_uid() ||
 222             shm_ds.shm_perm.cgid != sec_initial_gid()) {
 223                 DEBUG(0,("ERROR: we did not create the shmem "
 224                          "(owned by another user, uid %u, gid %u)\n",
 225                          shm_ds.shm_perm.cuid,
 226                          shm_ds.shm_perm.cgid));
 227                 return False;
 228         }
 229
 230         if (shm_ds.shm_segsz != sizeof(*profile_h)) {
 231                 DEBUG(0,("WARNING: profile size is %d (expected %d). Deleting\n",
 232                          (int)shm_ds.shm_segsz, sizeof(*profile_h)));
 233                 if (shmctl(shm_id, IPC_RMID, &shm_ds) == 0) {
 234                         goto again;
 235                 } else {
 236                         return False;
 237                 }
 238         }
 239
 240         if (!read_only && (shm_ds.shm_nattch == 1)) {
 241                 memset((char *)profile_h, 0, sizeof(*profile_h));
 242                 profile_h->prof_shm_magic = PROF_SHM_MAGIC;
 243                 profile_h->prof_shm_version = PROF_SHM_VERSION;
 244                 DEBUG(3,("Initialised profile area\n"));
 245         }
 246
 247         profile_p = &profile_h->stats;
 248         message_register(MSG_PROFILE, profile_message);
 249         message_register(MSG_REQ_PROFILELEVEL, reqprofile_message);
 250         return True;
 251 }
 252 #endif /* WITH_PROFILE */