lib/libexec/exec_general.c

   1 #define _SYSTEM 1
   2
   3 #include <minix/type.h>
   4 #include <minix/const.h>
   5 #include <sys/param.h>
   6 #include <assert.h>
   7 #include <unistd.h>
   8 #include <errno.h>
   9 #include <libexec.h>
  10 #include <string.h>
  11 #include <assert.h>
  12 #include <minix/ipc.h>
  13 #include <minix/com.h>
  14 #include <minix/callnr.h>
  15 #include <minix/vm.h>
  16 #include <minix/ipc.h>
  17 #include <minix/syslib.h>
  18 #include <sys/mman.h>
  19 #include <machine/elf.h>
  20
  21 int libexec_alloc_mmap_prealloc(struct exec_info *execi, off_t vaddr, size_t len)
  22 {
  23         if(minix_mmap_for(execi->proc_e, (void *) vaddr, len,
  24                 PROT_READ|PROT_WRITE|PROT_EXEC,
  25                 MAP_ANON|MAP_PREALLOC|MAP_UNINITIALIZED|MAP_FIXED, -1, 0) == MAP_FAILED) {
  26                 return ENOMEM;
  27         }
  28
  29         return OK;
  30 }
  31
  32 int libexec_alloc_mmap_ondemand(struct exec_info *execi, off_t vaddr, size_t len)
  33 {
  34         if(minix_mmap_for(execi->proc_e, (void *) vaddr, len,
  35                 PROT_READ|PROT_WRITE|PROT_EXEC,
  36                 MAP_ANON|MAP_FIXED, -1, 0) == MAP_FAILED) {
  37                 return ENOMEM;
  38         }
  39
  40         return OK;
  41 }
  42
  43 int libexec_clearproc_vm_procctl(struct exec_info *execi)
  44 {
  45         return vm_procctl(execi->proc_e, VMPPARAM_CLEAR);
  46 }
  47
  48 int libexec_clear_sys_memset(struct exec_info *execi, off_t vaddr, size_t len)
  49 {
  50         return sys_memset(execi->proc_e, 0, vaddr, len);
  51 }
  52
  53 int libexec_copy_memcpy(struct exec_info *execi,
  54         off_t off, off_t vaddr, size_t len)
  55 {
  56         assert(off + len <= execi->hdr_len);
  57         memcpy((char *) vaddr, (char *) execi->hdr + off, len);
  58         return OK;
  59 }
  60
  61 int libexec_clear_memset(struct exec_info *execi, off_t vaddr, size_t len)
  62 {
  63         memset((char *) vaddr, 0, len);
  64         return OK;
  65 }
  66
  67 void libexec_patch_ptr(char stack[ARG_MAX], vir_bytes base)
  68 {
  69 /* When doing an exec(name, argv, envp) call, the user builds up a stack
  70  * image with arg and env pointers relative to the start of the stack.  Now
  71  * these pointers must be relocated, since the stack is not positioned at
  72  * address 0 in the user's address space.
  73  */
  74
  75   char **ap, flag;
  76   vir_bytes v;
  77
  78   flag = 0;                     /* counts number of 0-pointers seen */
  79   ap = (char **) stack;         /* points initially to 'nargs' */
  80   ap++;                         /* now points to argv[0] */
  81   while (flag < 2) {
  82         if (ap >= (char **) &stack[ARG_MAX]) return;    /* too bad */
  83         if (*ap != NULL) {
  84                 v = (vir_bytes) *ap;    /* v is relative pointer */
  85                 v += base;              /* relocate it */
  86                 *ap = (char *) v;       /* put it back */
  87         } else {
  88                 flag++;
  89         }
  90         ap++;
  91   }
  92 }
  93
  94 int libexec_pm_newexec(endpoint_t proc_e, struct exec_info *e)
  95 {
  96   int r;
  97   message m;
  98
  99   m.m_type = PM_NEWEXEC;
 100   m.EXC_NM_PROC = proc_e;
 101   m.EXC_NM_PTR = (char *)e;
 102   if ((r = sendrec(PM_PROC_NR, &m)) != OK) return(r);
 103
 104   e->allow_setuid = !!(m.m1_i2 & EXC_NM_RF_ALLOW_SETUID);
 105
 106   return(m.m_type);
 107 }