src/afs/AIX/osi_gcpags.c

   1 /*
   2  * Copyright 2000, International Business Machines Corporation and others.
   3  * All Rights Reserved.
   4  *
   5  * This software has been released under the terms of the IBM Public
   6  * License.  For details, see the LICENSE file in the top-level source
   7  * directory or online at http://www.openafs.org/dl/license10.html
   8  */
   9
  10 #include <afsconfig.h>
  11 #include "afs/param.h"
  12
  13
  14 #include "afs/sysincludes.h"    /* Standard vendor system headers */
  15 #include "afsincludes.h"        /* Afs-based standard headers */
  16 #include "afs/afs_stats.h"      /* afs statistics */
  17 #include <sys/adspace.h>        /* for vm_att(), vm_det() */
  18
  19 #if AFS_GCPAGS
  20
  21 /* afs_osi_TraverseProcTable() - Walk through the systems process
  22  * table, calling afs_GCPAGs_perproc_func() for each process.
  23  */
  24
  25 #ifdef AFS_AIX51_ENV
  26 #define max_proc v.ve_proc
  27 #endif
  28 void
  29 afs_osi_TraverseProcTable(void)
  30 {
  31     afs_proc_t *p;
  32     int i;
  33
  34     /*
  35      * For binary compatibility, on AIX we need to be careful to use the
  36      * proper size of a struct proc, even if it is different from what
  37      * we were compiled with.
  38      */
  39     if (!afs_gcpags_procsize)
  40         return;
  41
  42 #ifndef AFS_AIX51_ENV
  43     simple_lock(&proc_tbl_lock);
  44 #endif
  45     for (p = (afs_proc_t *)v.vb_proc, i = 0; p < max_proc;
  46          p = (afs_proc_t *)((char *)p + afs_gcpags_procsize), i++) {
  47
  48 #ifdef AFS_AIX51_ENV
  49         if (p->p_pvprocp->pv_stat == SNONE)
  50             continue;
  51         if (p->p_pvprocp->pv_stat == SIDL)
  52             continue;
  53         if (p->p_pvprocp->pv_stat == SEXIT)
  54             continue;
  55 #else
  56         if (p->p_stat == SNONE)
  57             continue;
  58         if (p->p_stat == SIDL)
  59             continue;
  60         if (p->p_stat == SEXIT)
  61             continue;
  62 #endif
  63
  64         /* sanity check */
  65
  66         if (PROCMASK(p->p_pid) != i) {
  67             afs_gcpags = AFS_GCPAGS_EPIDCHECK;
  68             break;
  69         }
  70
  71         /* sanity check */
  72
  73         if ((p->p_nice < P_NICE_MIN) || (P_NICE_MAX < p->p_nice)) {
  74             afs_gcpags = AFS_GCPAGS_ENICECHECK;
  75             break;
  76         }
  77
  78         afs_GCPAGs_perproc_func(p);
  79     }
  80 #ifndef AFS_AIX51_ENV
  81     simple_unlock(&proc_tbl_lock);
  82 #endif
  83 }
  84
  85 /* return a pointer (sometimes a static copy ) to the cred for a
  86  * given afs_proc_t.
  87  * subsequent calls may overwrite the previously returned value.
  88  */
  89
  90 /* GLOBAL DECLARATIONS */
  91
  92 /*
  93  * LOCKS: the caller must do
  94  *  simple_lock(&proc_tbl_lock);
  95  *  simple_unlock(&proc_tbl_lock);
  96  * around calls to this function.
  97  */
  98
  99 const afs_ucred_t *
 100 afs_osi_proc2cred(afs_proc_t * pproc)
 101 {
 102     afs_ucred_t *pcred = 0;
 103
 104     /*
 105      * pointer to process user structure valid in *our*
 106      * address space
 107      *
 108      * The user structure for a process is stored in the user
 109      * address space (as distinct from the kernel address
 110      * space), and so to refer to the user structure of a
 111      * different process we must employ special measures.
 112      *
 113      * I followed the example used in the AIX getproc() system
 114      * call in bos/kernel/proc/getproc.c
 115      */
 116     struct user *xmem_userp;
 117
 118     struct xmem dp;             /* ptr to xmem descriptor */
 119     int xm;                     /* xmem result */
 120
 121     if (!pproc) {
 122         return pcred;
 123     }
 124
 125     /*
 126      * The process private segment in which the user
 127      * area is located may disappear. We need to increment
 128      * its use count. Therefore we
 129      *    - get the proc_tbl_lock to hold the segment.
 130      *    - get the p_lock to lockout vm_cleardata.
 131      *    - vm_att to load the segment register (no check)
 132      *    - xmattach to bump its use count.
 133      *    - release the p_lock.
 134      *    - release the proc_tbl_lock.
 135      *    - do whatever we need.
 136      *    - xmdetach to decrement the use count.
 137      *    - vm_det to free the segment register (no check)
 138      */
 139
 140     xmem_userp = NULL;
 141     xm = XMEM_FAIL;
 142     /* simple_lock(&proc_tbl_lock); */
 143 #ifdef __64BIT__
 144     if (pproc->p_adspace != vm_handle(NULLSEGID, (int32long64_t) 0)) {
 145 #else
 146     if (pproc->p_adspace != NULLSEGVAL) {
 147 #endif
 148
 149 #ifdef AFS_AIX51_ENV
 150         simple_lock(&pproc->p_pvprocp->pv_lock);
 151 #else
 152         simple_lock(&pproc->p_lock);
 153 #endif
 154
 155         if (pproc->p_threadcount &&
 156 #ifdef AFS_AIX51_ENV
 157             pproc->p_pvprocp->pv_threadlist) {
 158 #else
 159             pproc->p_threadlist) {
 160 #endif
 161
 162             /*
 163              * arbitrarily pick the first thread in pproc
 164              */
 165             struct thread *pproc_thread =
 166 #ifdef AFS_AIX51_ENV
 167                 pproc->p_pvprocp->pv_threadlist;
 168 #else
 169                 pproc->p_threadlist;
 170 #endif
 171
 172             /*
 173              * location of 'struct user' in pproc's
 174              * address space
 175              */
 176             struct user *pproc_userp = pproc_thread->t_userp;
 177
 178             /*
 179              * create a pointer valid in my own address space
 180              */
 181
 182             xmem_userp = (struct user *)vm_att(pproc->p_adspace, pproc_userp);
 183
 184             dp.aspace_id = XMEM_INVAL;
 185             xm = xmattach(xmem_userp, sizeof(*xmem_userp), &dp, SYS_ADSPACE);
 186         }
 187
 188 #ifdef AFS_AIX51_ENV
 189         simple_unlock(&pproc->p_pvprocp->pv_lock);
 190 #else
 191         simple_unlock(&pproc->p_lock);
 192 #endif
 193     }
 194     /* simple_unlock(&proc_tbl_lock); */
 195     if (xm == XMEM_SUCC) {
 196
 197         static afs_ucred_t cred;
 198
 199         /*
 200          * What locking should we use to protect access to the user
 201          * area?  If needed also change the code in AIX/osi_groups.c.
 202          */
 203
 204         /* copy cred to local address space */
 205         cred = *xmem_userp->U_cred;
 206         pcred = &cred;
 207
 208         xmdetach(&dp);
 209     }
 210     if (xmem_userp) {
 211         vm_det((void *)xmem_userp);
 212     }
 213
 214     return pcred;
 215 }
 216
 217
 218 #endif /* AFS_GCPAGS */