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