LXR linux-old/kernel/exec

   1#include <linux/personality.h>
   2#include <linux/ptrace.h>
   3#include <linux/sched.h>
   4#include <linux/mm.h>
   5
   6static asmlinkage void no_lcall7(struct pt_regs * regs);
   7
   8
   9static unsigned long ident_map[32] = {
  10        0,      1,      2,      3,      4,      5,      6,      7,
  11        8,      9,      10,     11,     12,     13,     14,     15,
  12        16,     17,     18,     19,     20,     21,     22,     23,
  13        24,     25,     26,     27,     28,     29,     30,     31
  14};
  15
  16struct exec_domain default_exec_domain = {
  17        "Linux",        /* name */
  18        no_lcall7,      /* lcall7 causes a seg fault. */
  19        0, 0xff,        /* All personalities. */
  20        ident_map,      /* Identity map signals. */
  21        ident_map,      /*  - both ways. */
  22        NULL,           /* No usage counter. */
  23        NULL            /* Nothing after this in the list. */
  24};
  25
  26static struct exec_domain *exec_domains = &default_exec_domain;
  27
  28
  29static asmlinkage void no_lcall7(struct pt_regs * regs)
  30{
  31        send_sig(SIGSEGV, current, 1);
  32}
  33
  34struct exec_domain *lookup_exec_domain(unsigned long personality)
  35{
  36        unsigned long pers = personality & PER_MASK;
  37        struct exec_domain *it;
  38
  39        for (it=exec_domains; it; it=it->next)
  40                if (pers >= it->pers_low
  41                && pers <= it->pers_high)
  42                        return it;
  43
  44        /* Should never get this far. */
  45        printk(KERN_ERR "No execution domain for personality 0x%02lx\n", pers);
  46        return NULL;
  47}
  48
  49int register_exec_domain(struct exec_domain *it)
  50{
  51        struct exec_domain *tmp;
  52
  53        if (!it)
  54                return -EINVAL;
  55        if (it->next)
  56                return -EBUSY;
  57        for (tmp=exec_domains; tmp; tmp=tmp->next)
  58                if (tmp == it)
  59                        return -EBUSY;
  60        it->next = exec_domains;
  61        exec_domains = it;
  62        return 0;
  63}
  64
  65int unregister_exec_domain(struct exec_domain *it)
  66{
  67        struct exec_domain ** tmp;
  68
  69        tmp = &exec_domains;
  70        while (*tmp) {
  71                if (it == *tmp) {
  72                        *tmp = it->next;
  73                        it->next = NULL;
  74                        return 0;
  75                }
  76                tmp = &(*tmp)->next;
  77        }
  78        return -EINVAL;
  79}
  80
  81asmlinkage int sys_personality(unsigned long personality)
  82{
  83        struct exec_domain *it;
  84        unsigned long old_personality;
  85
  86        if (personality == 0xffffffff)
  87                return current->personality;
  88
  89        it = lookup_exec_domain(personality);
  90        if (!it)
  91                return -EINVAL;
  92
  93        old_personality = current->personality;
  94        if (current->exec_domain && current->exec_domain->use_count)
  95                (*current->exec_domain->use_count)--;
  96        current->personality = personality;
  97        current->exec_domain = it;
  98        if (current->exec_domain->use_count)
  99                (*current->exec_domain->use_count)++;
 100
 101        return old_personality;
 102}
 103